Build Your Own Doug Coil Machine.ppt

Build your own Doug Coil Machine Easy to follow steps with clear explanations and numerous photographs

Written by John Stolar Professor of Geology/Astronomy (ret) And Lyme victim

Dedication It is important to recognize the efforts of those rare individuals who make a difference in the lives of large numbers of people. I would like to dedicate this tutorial to two such people who helped many who recovered their lives from pain and despair to having hope and light. Doug MacLean designed what is now known as the “Doug Coil Machine” and showed what could be achieved with ingenuity and amazing curiosity. His discoveries are admired by many thousands who appreciate his contributions to all of us. John Propster designed the current model of the Doug Coil Machine and touched lives that he could not possibly imagine. Our gratitude to these exceptional individuals is well deserved. Thank you, Doug and John, for making a difference.

Disclaimer page Coil machines are not approved for the treatment of any disease or condition by the Federal Drug Administration or any other government, public, or private agency. Coil machines are not recommended for use on humans since the effects have not been fully researched and understood. Women who are pregnant and anyone having a pacemaker should not use a coil machine. Precautions regarding electrical devices and magnetic fields should be taken. Coil machines are for the purpose of experimental investigation into the effects of electromagnetic frequencies and magnetic fields. Users having serious medical conditions should heed the advice of competent and trained medical personnel. Do not substitute the use of a coil machine for competent medical advice and counseling. It should be understood that human biological responses to coil machines are not fully known. It is understood that the user is responsible for experimental investigation and accepts all responsibility for the use of this device. The user cannot hold the author of this coil machine tutorial responsible for any consequences that may result from the building of this device.

Introduction This presentation will organize the construction of a Doug coil machine (DCM) in a logical series of steps and will provide detailed explanations and illustrate the steps with many sequential photographs of a DCM being built. A person with no electrical experience will be able to complete this project safely with some basic tools and common sense. The tutorial took over 200 hours to complete. It contains 150+ photographs and 139 PowerPoint pages covering all of the topics Involved in building a Doug Coil Machine. The purpose for producing such a thing is to provide some aid to my fellow Lyme-infected sufferers - its my chance in life to do something good for a large number of people, most of whom, unfortunately, I will never meet. Not many people get a chance like this so for this reason, this CD will always be free. The material in the tutorial can be shared, copied, and printed but cannot be included in part or its entirety in any publication or in any other medium that will be sold. My point is to help people – not to take their money. If you find that you don’t understand something in the tutorial or have questions, please feel free to email me at: [email protected].

Table of Contents Pages 5 6 -8 9 - 14 15 - 20 21 - 40 41 - 43 44 - 47 48 - 50 51 - 54 55 - 63 64 - 84 85 - 101 102 - 106 107 - 108 109 - 122 123 - 129 130 - 138 139

Schematic of a DCM Tools and Materials Operating a DCM, Shutdown Procedure Coils Coil Winding Device, soldering speaker wire to the coil Measuring your Coil’s Inductance Multimeter Amplifier Switches Capacitors Making Capacitor Arrays Connecting the Capacitor Arrays to the Switches Resistors Wave/Signal Generator Coil Stand Doug Coil Machine on a Cart New and Alternate Ideas Section Encouragement Page

signal generator

The Instek SFG 2004 signal generator comes with a cable that plugs into the BNC jack on the bottom right of the generator and alligator clips on the other end. I cut the clips off and attached fork connectors. The red wire should be attached to Channel 1 + and the black wire to the Channel 1 – terminals. Use a small wire loop to connect the – terminal and the ground terminals together.

Schematic of a DCM amplifier input

QSC1850HD amplifier (back) Mode Switches all are off (push sliders to the left) except for #4 and #5 parallel inputs

barrier strip (screws) Channel 1 & 2 inputs

amplifier output _

Channel 1

+ + Channel 2 _ connect top & bottom terminals with 12 gauge wire loop

double binding post

12 ga..speaker wire

coil wire nuts connecting 2 coil wires and speaker wires

all other switches

all other switches

cap arrays (2 are shown there are 15)

switch A

2 sets of 5 resistors each

volt meter

no caps on switch A

A terminal block with two rows of 8 screws each (rated 20 amps) could be used here. See terminals blocks on P.137 near the end of the tutorial.

Tools and Materials • • • • • • • •

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wire cutter and insulation stripper electrician’s pliers for twisting wires together needle-nosed pliers (for reaching where fingers can’t fit) electric soldering iron or gun Solder - rosin core, .062” diameter works well wire nuts: (2 yellow size for each coil) (3 large grey size) ( 20+/- red size) (3 blue – very large size for 5 or 6 (12 gauge wires). If you use terminal blocks instead you will need two double row, 8 screw blocks.

44 female spade connectors for 12 gauge wire wire connector crimping pliers cable ties 11” length (for banding the wire in a coil and for holding the coil to the stand) cable ties 7” length (for banding capacitors to mounts or to a panel - about 25 needed) cable tie mounting bases (for mounting capacitors and resistors but a ¼” plywood panel and cable ties works well) electric drill or drill press, 1/2”, 5/8, and 1” Forstner bits, Phillips driver bit

Electrician’s pliers Wire stripper and cutter This tool is specifically made for 12 gauge wire. Other sizes are available but this may the most important tool for this project so to avoid much wasted time – get the 12 gauge one.

Wire nuts

Blunt ends allow for twisting 3+ wires together

Wire connector crimping tool. This does a much better job than regular pliers. Notice the bare wire inside the connector- the insulation should be stripped so the tinned metal sleeve is crimped around bare copper wire. Get female connectors that are made for 10 or 12 gauge wire.

Soldering iron with temperature control and hot iron rest stand. Soldering is mostly done to secure capacitors together in a DCM. Cost is about $16. Check http://www.elexp.com for parts and tools

Soldering iron – no temp. control and no rest stand

Operating the DCM Knowing how to operate the DCM before building it may help people understand how the components work together. 1. Place the coil so the hole faces you. It can lean on something sturdy or can hang with ties to the back of a wooden chair, etc. It can get hot (well over 100 F) so be sure to keep plastic items away from the coil. Electrical tape can melt if used to hold a coil together or to hold it in place while in use. Details are given later in this tutorial for building a coil stand. Be sure to place the coil at least 6 or 8 feet away from TVs, stereos, computers, memory cards, digital cameras, and credit cards. The coil’s magnetic field may interfere with these things in addition to other things in your home. Plug the end of the 15 ft 12 gauge wire attached to the coil into the binding post jacks on the DCM. 2. Turn the multimeter on and set the dial for V~ (volts AC current) and use the RANGE button to set the units shown on the LCD screen of the meter to V~ (not mV which is millivolts). Be sure to dial the V~ for alternating current and not V---- for direct current. The manual helps here. The test lead wires coming out of the multimeter (with alligator clips to hold the test leads in place) must be placed at both sides of a set of 5 resistors (see picture on next page) that are soldered together. Be sure to plug in the black test lead wire into the black jack (or Com) in the multimeter and the red test lead in the red jack that has V next to it.

Two sets of five resistors each. The red alligator clip test lead Is attached to one side of a set of resistors and the black test lead is connected to the other side. Details on soldering the resistors together are given in the section on Resistors

This is how the meter should be setup to operate the DCM. Notice the positions of the red and black test leads. The dial is pointing to V~ and the “Range” button was pushed to get the decimal behind the first zero since the meter will read 1.500 volts when the DCM is in use.

1. Turn on the signal generator and input a frequency such as 432 and push the Hertz button. Push the “Wave “ button to get the curvy sine curve icon. Push “Shift” and “8” to get the -20db icon. This subtracts current from the input to the amplifier so the “Ampl” knob is much less sensitive and can be adjusted better. The generator is now outputting waves of the frequency you chose. You could check this by setting your multimeter dial to Hz and using its test lead wires to touch the end of the red lead and the black lead wire. When you use a frequency from about 800Hz you will need to remove the -20db function or the meter may not be able to reach 1.5 volts when the machine is operating. 2. Turn on the amplifier with its rocker switch – be sure that the 2 volume dials on the front of the amplifier are turned counter clockwise to zero. 3. Flip the correct toggle switches up to the ON position to set the required capacitance for the frequency you chose. (See the section on capacitors) 4. Turn both amplifier dials clockwise to the maximum position

5. Turn the “Ampl” knob up on the signal generator until the reading on the LCD multimeter display reads 1.5 volts. The coil machine is ready to use. It hums fairly loudly. The coil heats up in time so if the phone rings – let it ring. If the red clip lights on the amplifier ever go on turn the “AMPL” knob CCW to lower the current. The coil can get hot so it should be on a stand that you can hold or get close to. It is recommended that you have a fan blowing on the coil for cooling purposes and for ventilation. The plastic insulation on the wire in the coil can emit fumes if the coil exceeds 235 F. so be sure to be in a well ventilated room – a closet would not be suitable. 6. When you finish with one frequency and want to choose another, turn the “AMPL” knob off and both gain knobs on the amplifier counterclockwise to zero. Don’t change capacitor toggle switches when the amplifier volume dials are anywhere other than zero. This prevents overloading the capacitors with electric current.

7. Pull capacitance toggle switches down to the off position and turn on the new set of switches for the new frequency. (see the freq cap calculator on the CD). 8. Repeat the procedure on the signal generator but with the new frequency 9. Turn up both amplifier volume dials to maximum, turn the signal generator volume dial so the multimeter again reads 1.5 volts. 10. That’s it – you just repeat the procedure for another frequency. You will notice that a fan in the amplifier begins running at a higher speed a few minutes into the use of the coil. This is normal to control overheating of the amplifier. If the heating is more than the fan can handle the amplifier stops its output of current to the coil and shuts down until cooled and then restarts automatically – you can resume using the coil at that point.

Shutdown Procedure

Shutdown is simply the reverse of the steps you do to operate the DCM Turn the “AMPL” knob off, Turn the amplifier gain knobs off (counterclockwise all the way) Flip capacitor toggle switches to off (in the down position) however the switches can be left on but it is advised to check that the correct switches are turned on Turn both the multimeter and signal generator off. Keep the amplifier on for a few minutes to cool. The air coming out of the front of the amplifier will be warm or hot at first. Push the rocker switch to off after the air feels cool.

Coils Insulated copper wire coils are used to produce magnetic fields that change the positions of the magnetic poles at different frequencies. For instance at a frequency of 432 Hz the magnetic poles change position 432 times per second Coils differ from one another in various ways such as 1. different size (gauge) insulated wire, DCM coils use 12 gauge insulated solid copper wire. The copper is 2mm in diameter and with the insulation it is 3mm in diameter. 2. different thickness of wire insulation 3. different width and thickness of coil dimensions (width and thickness) 4. variation in tightness of wraps A general rule is that the more wire you can get into a coil of a given volume, the higher the coil’s inductance will be.

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An electrical measurement that is important for building a DCM is the inductance of the coil. Inductance for our purpose is not important to understand in depth but a short definition is that inductance is the ability of a coil carrying an electric current to resist a change in the current flowing through the coil. Another way to understand inductance is that it is a measure of the amount of copper in a cross section of a coil if the coil could be cut across the wires. Coils that have an alternating (the current travels in a wave form) electric current running through them produce an alternating magnetic field. Moving electric current (charged particles) automatically produces a magnetic field. Even hot gas becomes charged and produces very strong magnetism due to movement of the gas as in the surface of the sun.

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The reason Inductance is important is that it is related mathematically to frequency and capacitance. If we know two of these values we can calculate the third one.

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For example when make a coil you physically measure its inductance with your multimeter. This gives you one of the values needed. You choose what frequency to generate with your signal generator – so now you have two of the values. A calculator program supplied on this CD will allow you to get the desired capacitance so you can turn on the correct capacitors to generate an alternating magnetic with your coil.

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Most coil machine builders have one coil. This coil with an inductance of 7 to 8 millihenries (mh) will easily produce alternating magnetic fields from about 20 pole reversals per second to about 2000. The unit of frequency is Hertz where 1 Hertz is one pole reversal per second. To have higher frequencies you will need a coil of lower inductance approximately in the range of 4 to 5 mh. Overheating of the amplifier is the result of attempting to generate higher frequency with a high inductance coil (you should use a low inductance coil for the frequencies over approximately 2000 Hz. You can try all of this out on the calculator by typing in various frequencies and inductances to see how capacitance changes How do you make a coil of lower inductance? less wire - accomplished by less width and thickness of your coil (assuming you still have tight windings).

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For example – a coil I wrapped with 12 gauge solid, insulated THNN wire (available in 500 foot spools at all Lowe’s and Home Depot stores) that measures 2 inches wide and 1.5 inches thick, wound very tightly, measured an inductance of 8.51 mh. This coil has 12 layers of wire in the 1.5 inch thickness and 16 rows of wire in the 2 inch width. It contains approximately 425 - 450 feet of wire. The coil was wrapped around a 6 inch form (described in detail in later slides) so the finished coil has a 6 inch diameter hole in its center. The outside diameter of the entire coil is 9 inches.

A coil wrapped with the same gauge wire on the same form and measuring 1.5” in thickness and 1.75” in width has an inductance of 7.20 mh. This coil has 15 layers on wire in the 1.5” of thickness and 13 rows of wire in the 1.75” of width. This coil has the 6” diameter hole and 9” outside diameter Another coil wrapped with the same gauge wire on the same form but this time the width and thickness both are 1 3/8” now has an inductance of 2.98 mh. This coil has 11 layers of wire in the 1 3/8” thickness and 11 rows of wire in the 1 3/8” of width. This coil has the 6” diameter hole and 9” outside diameter . A coil that is too large in width and thickness and tightly wound could have an inductance of 12 mh or more and prove to be useless for higher frequencies. What matters is that you end up with a coil of about 7 to 8 mh if you intend to have only one coil. If your coil comes out slightly higher or lower, it doesn’t matter significantly because the capacitors you will switch on for a particular frequency will change with the inductance of the coil you make. That is precisely why this tutorial cannot supply you with a list of capacitor switches to use for a given frequency you wish to generate since your personal coil determines this factor. You don’t have to calculate anything since there is a calculator program on this CD that will calculate everything you need. It is all very easy.

Measuring Inductance with a Multimeter

Notice the position of the dial. It is pointing to the mH symbol (Henry is the unit of measure for inductance). Also notice that the red test lead is plugged into the far left red socket labeled with an H. The coils are not connected to a coil machine in these pictures. The magnetic field is very strong in the hole area of the coil and would produce heating in any metallic object placed there – your meter would be ruined.

Coil dimensions and Inductance (all coils have 6” diameter holes and are wrapped with 12 gauge THNN solid copper wire)

coil size

layers of wire

rows of wire

inductance

1 3/8” thick x 1 3/8” wide

11 layers

11 rows

2.98 mH

1 3/8” thick x 1 ½” wide

12 layers

12 rows

4.39 mH

1 ¼” thick x 2” wide

11 layers

15 rows

7.01 mH

1.5” thick x 1.75” wide

15 layers

13 rows

7.20 mH

1.5” thick x 2’ wide

12.5 layers

16 rows

8.49 mH

1.5” thick x 2” wide

12 layers

16 rows

8.51 mH

These coils were wrapped over a 3 week period. It seems apparent that there must be some variation in either the thickness of the insulation on the wire or of the tension on the wire during wrapping. It is assumed that the copper wire is the same diameter. The spool winder was very rigid and is not a factor in introducing extra rows in some coils. Three of the coils are 2” wide but one coil has an extra row. Wire tension during winding has more of an effect on the number of layers than on the number of rows so this is one of those things to ponder( I suspect that if wraps nestle in between the wire wraps below them throughout the coil you will get a higher inductance coil than if layers of wire sit exactly on top of the wires in the layer below). Some of each happens in every coil. The 8.49 mH coil had 13 layers but I removed half of the last layer to get the inductance down from 9.58 to 8.49 mH. I removed the wire foot by foot and checked the inductance continually. It was surprising how much the inductance changed with the removal of just a few wraps of wire.

Coil Winding Device There are many good ways to wrap insulated solid copper wire tightly enough to make a good coil. I wrapped 50+ coils in seven months with the device I made and of course the last one is better than the first. I decided that I needed firm sides on the form I would wrap the wire upon. That decision eliminated anything that would flex with pressure so I used ¾” thick (actually .707 inches thick and not .75”) birch plywood. A series of pictures illustrating the making of the winding device is on the next slides. The first step was to use a compass to draw a 6” diameter circle on the birch plywood. A 9” diameter circle was drawn using the same center point as for the 6” circle. This resulted in two concentric circles. I drew a line across the largest circle and through the center point and then drew lines 15 degrees apart (I used a plastic protractor) from the center of both circles out to the 6” circle. Thirty 3/8” holes would be drilled at these15 degree intervals along the inside of the 6” circle. It is necessary to only draw the circles and lines on one of the plywood pieces since they will be taped together so the drilling of 3/8” holes results in two identical pieces.

I used a band saw to cut out the circles (you cut on the outside of the line of the 9” circle).

These are 15 degree spaces on the 6” circle. A 3/8” hole will be drilled inside the 6 inch circle at the end of each line. The drilled holes will all be inside the 6” circle and not cross over into the space between the 6” and 9” circles. The center of each 3/8” hole should be on the lines pointed to by the blue arrow.

These are 8 areas where slots will be cut to hold the cable ties that will eventually hold the wire coil together. It’s a nice way to have the ties held in place while winding wire. The birch plywood is stained because it was a shelf from a large TV cabinet I made. I got a larger TV and didn’t need the cabinet any more.

The holes are completely inside the 6” circle. The dowels that are placed in the holes will form the surface that the wire is wound upon. Note that the disks are taped together so they can be drilled together. The dark holes are charred wood caused by a dull drill bit. Its easy to see what a sharp drill bit does on the other holes. The sharp bit I used is a brad point wood drill bit. It has a pointed tip which makes it easy to see where the center of the hole will be when the bit is turning in the drill.

Both plywood circles were drilled at the same time. To do otherwise would make it impossible to join the two disks together with dowels. The disks must be in the orientation shown. To assemble, the disk on the right will end up on the outside of the winding spool and the surface of the disk on the left will be on the inside of the winding spool. The arrows show the alignment of the disks when they were taped and drilled.

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beeswax The grooves were cut with a radial arm saw but there are other ways to cut the grooves – but none as easy as with a radial arm saw. A sharp chisel would work but it would be slow. The blade is raised otherwise I would cut the disk into pieces. Since the saw blade teeth are 1/8” wide and the cable ties that will go Into the grooves are wider, you need to make several cuts to fit the ties. A groove slightly large is better than a groove that is too narrow. The depth of each groove is slightly deeper than a cable tie is thick. Notice how these grooves are between the holes. This is so the cable ties can slide easily in the grooves.

Drill a 5/8 inch hole for a dowel or iron rod so the winding spool can easily turn.

I highly recommend oak 3/8” dowel rods (from Home Depot). The are tough and will take the hammering required to assemble the winding spool for winding a coil and taking it apart to get the wire coil off. I waxed them with bees wax to make them easier to use. The dowels are 3 ½” long. This length allows them to be firmly in each disk and to have 2” of space between disks for winding a 2” wide wire coil. If you want to wind wider coils – make the dowels respectively longer.

The head of this rubber hammer is filled with lead shot. The inertia of the shot gives solid hits.

All of the dowels are inserted into the holes and are flush with the other side of this disk

The winding spool is assembled. I recommend driving the dowels Into a disk as it sits on a firm surface. A rubber hammer will not dent and destroy your wood disks and dowels like a metal hammer will soon do. After all the dowels are in the first disk as shown to the left, it is a little tricky to get the second disk started onto the dowels. If you slightly tilt the second disk you can get a few dowels started into the holes of the second disk and just slowly work your way around the perimeter. You will have to use your fingers to force some dowels into alignment. Don’t hammer on the outer rim – it might break – hammer inside of the ring of the dowel holes

1 1/2”

10”

Notice the dowels are sticking out of what was the top disk shown in the previous picture. If the dowels would be flush with both disks, the gap between the disks would be 2” wide for a 2” wide wire coil.

Since I wanted to wind a 1 3/8” wide coil, I placed 4 wood blocks exactly 1 3/8” long between the plywood disks and then I used the rubber hammer to drive the disks together. That is why the dowels are sticking out of the disk In this picture. Remove the blocks and you are ready to wind a coil.

A length of ½” steel rod makes a good axle but a wood dowel would be fine. The distance between the dowel rods in the gap between the disks out to the outside edge of the disks is 1 ½” so the wire coil will be 1 ½” thick. grooves for the cable ties

2 ½”

10” 7 ¼“

This is one cable tie, the locking socket on the right end and the tongue end on the left. It loops down between the dowels and is held in place in the grooves. I used 11” cable ties because 8” ties are not long enough to pull tight easily.

Clamp to hold wire roll holder The coil winding spool. I used 3” long screws through the 2x4 bottom of each wire roll stand and into the end of the 2x4 upright pieces. This is simply a U-shaped structure.

This the roll of wire that will be wound onto the winding spool to make the wire coil.

A small hole is drilled here to secure the end of the wire to start the coil. Without this hole the stiff 12 gauge wire could not be pulled tight enough to start the first layer of wire

Cable ties in grooves

The first wrap - the start of a good coil is based on having tight layers and rows.

Once you start to wind a coil you can’t stop unless you keep a piece of duct tape handy and can tape down the wire on your coil – it will unwind for several layers if you release the tension

The wire is wound inch by inch with constant tension with the fingers to keep the wraps tight. There is nothing fast about this part. Try not to impart bends in the wire by the finger or fingers that “lay” the wire in place. I used my right index finger to lay the wire in place while turning the spool with my left hand. You will find that you need to pry wraps of wire to get a tight row and to get the last wrap of the row tight against the plywood. I used a screwdriver with a flat bladed end to pry gently – great care must be taken to not cut the insulation of the wire. I used a small wood block to push the wire down into the space created.

The coil is finished. Now the cable ties can be tightened. You can cut the wire off leaving about 10” remaining.

Push the socket end of the cable tie down into the groove in the wood disk so about ½” of the tie sticks up above the wire. Put the tongue end into the socket and pull to the left so the cable is tight. Don’t over do it with the tightening as the tie can cut the insulation. The cable tie in this picture has not been tightened yet. The cable tie in the background has been pulled and tightened. You can trim the excess length off all cable ties.

Use an oak dowel and a rubber hammer to drive the dowels one by one through the top plywood disk. Sand or file this dowel (at least the first 1 ½” or so) so it doesn’t stick in the hole

Hang the edge of the spool over the edge of a work table or other solid surface and hammer the dowels through the top disk Once about 10 of the dowels are sticking out on the other side of the spool – you can then just balance the entire spool on those dowels to hammer the rest of the dowels out without hanging the spool over the edge of the workbench.

All of the dowels are now through the top plywood disk.

The work is almost finished. It took 45 minutes to wrap this coil. After making 50 coils I can wrap the wire for a coil in 11 minutes.

Pry the coil off of the dowels with your fingers. If you can’t budge the wire coil you will need to hammer some dowels (hammer them to the left in this picture) so they clear the coil for removal.

This is a fairly low inductance coil. It is 1 3/8” wide and 1 ½” thick. The inductance is 4.39 micro henries (4.39mh) and will be used for frequencies over 2000 Hz.

Adding wire to a coil Let’s assume that you finished wrapping a coil and have cut the wire coming from the original roll of wire. Upon using your multimeter you find that the inductance of the coil is 5.6 mh and you were expecting a value closer to 7.6 mh. What to do is a question you will ask to no one in particular as you worry about having to buy another roll of wire. The next pictures show a simple jig you can make in a few minutes that will allow you to splice the wire back onto the coil and continue wrapping to get a thicker coil and therefore a higher inductance coil.

This jig is very simple. Start with a block of wood and screw two strips of wood to the block. The gap between the strips should be about 1 ½”. You should pre drill the screw holes so you don’t split the strips. The strips should be at least ½” thick. Cut two more identical strips and clamp one to each strip and drill holes through both strips. Put arrows on the top strip to show the orientation when both were drilled so you can reattach them. It helps to have A and B or 1 and 2 on the top strips also. Cut a groove across the top strips that is wide enough for 12 gauge wire but not as deep as the wire is thick so the wire can be clamped and held down when you screw the strips together.

Its difficult to see in this picture but the end of the wire has been cut at less than a 45 degree angle (cut the wire at a very shallow angle, placed in the groove and the wood strip has been screwed to the strip below to hold the wire in place. The wire stripper/cutter tool is ideal for cutting this angle. Regular wire cutters can’t cut as nice an angle since they are designed for just cross cutting. The wire shown is the end of the coil wire that needs to be extended.

The second wire has been angled and screwed down by its wood strip holder. Use needle nosed pliers to form the joint so it is as smooth a transition as possible. Be sure to slip a piece of heat shrink tubing onto one of the wires before placing them in the jig.

Use about a 3” length of a strand of stranded copper wire and tightly wrap the strand around the splice. You can see how small the bump is where the two wires meet. A large lump here would make your coil have a lump.

Here is the soldered joint. It is very strong and will allow you to continue to wrap a thicker coil.

Here the wires are out of the clamp. Shown is a piece of heat shrink tubing that is long enough to overlap the wire insulation on both sides. The last step is to carefully heat the tubing with a propane torch, a candle, or a lighter so it shrinks around your solder joint. Don’t over do it since you certainly don’t want to melt the wire insulation. If you forget the heat shrink tubing you will have to cut the joint off and start over.

Soldering banana plugs to the coil’s 15 ft. speaker wire

Banana plugs – 12 gauge speaker wire is soldered into the end of each plug. These are available at Radio Shack. There is a small screw-in adapter for smaller wire that I removed and discarded.

Since the flanged ends of the banana plugs are delicate you should not squeeze them with pliers. Here I used pliers and taped the handles together with just enough pressure to hold the plug so it can be soldered.

Heat the end of the banana plug with the soldering iron. Hold the roll in the other hand and insert the end of the solder into the hole carefully so it melts and almost fills the hole. While the solder is molten insert the end of one of speaker wires (strip about 3/8” of the insulation) into the hole and hold there until the solder hardens (about 10 seconds).

It is easy to forget to put the red or black plastic pieces onto the wire before soldering. Once the metal plug is soldered to the wire, the plastic insulator cannot be put on the wire. When the metal plugs cool, turn the plastic insulator onto the threaded plugs. The other ends of the speaker wires are connected to the two wires on the coil. It doesn’t matter which of the coil wires are attached to the red or black banana plugs, in fact you don’t need red black plug covers at all since any color will work fine.

Measuring your coil’s Inductance There are two ways to measure the inductance of the coil you wrapped. The first method is to simply buy a multimeter that can measure inductance. Since you will need a meter that also measures alternating current accurately to monitor the current flowing through the coil when in use, having the same meter measure inductance is very handy. The meter will have an H and mH on the dial for Inductance (measured in Henries

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If you already have a True RMS multimeter you can measure your coil’s inductance another way to avoid buying a meter that measures Inductance. Your DCM must be operable to use this method since you need to turn it on to measure your coil’s Inductance. Turn on the signal generator and set it for 470 Hz sine wave output. Turn on the 16 μf capacitor switch. Turn on your multimeter with the alligator clip lead wires connected to each set of 5 resistors – set dial to V~ for alternating current. Turn on the amplifier and turn the 2 gain dials until the yellow lights come on Turn the large dial (clockwise or counterclockwise) on the signal generator to change the frequency up or down to get the highest voltage reading on your multimeter you can get. Record the frequency you dialed on the signal generator when the multimeter reaches the highest voltage You can calculate the inductance with the formula below. .(the Inductance will be in Henries which means that you will need to move the decimal place 3 places to the right to change the unit to milliHenries – You can now use the Excel freq cap switch calculator on the CD by typing in the Inductance to get the switches that need to be turned on for a frequency you choose.)

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Inductance = 25330/Freq2 X 1/capacitance

You can use the following formula to calculate the capacitance you need for each frequency you want to generate if you choose to do the calculations manually. Capacitance = 25330/Freq2 Inductance The capacitance will be in microfarads, the frequency should be in Hertz, and the Inductance should be in Henries. An excellent calculator can also be found at www.opamplabs.com/cfl.htm. The above calculation can be done with the Excel calculator program called “freq cap calculator” given on the CD.

Multimeter A well built meter is the Wavetek Meterman 37XR. I purchased one from Electronix Express at 1-800-972-2225 or at http://www.elexp.com/tst_38xr.htm. An online search will produce many other meters for lower prices, I chose to get one that also measures inductance and because I like to buy tools. Meters are constantly discontinued and relabeled so don’t get locked into buying a particular model. I recommend searching online for best prices and free shipping. Goggle removed the Froogle option but you can still sort items by price. Do a search by model number and click the hypertext “Products” or “Shopping” at the top left of the page. Click in the menu bar “by lowest price” and you will see what is available. Sometimes searching like this is not absolute. I have searched for an item with a opened catalog next to me and searches many times don’t include the company whose catalog I have or their price.

One of the basic differences between expensive and the lowest cost multimeters is that the ranges of things like voltage will be limited in the cheapest meters. For example the range of voltage may be half as large on a low cost meter. The number of functions that you can measure is larger on the more expensive models also. Measuring inductance is great if you build coils but the price of a meter that measures inductance just one time is probably not necessary.

Shown is an example of meter at http://elexp.com/tst_205e.htm. There are literally hundreds of meters that you can buy.

Range button moves the decimal point

This is the dial setting for voltage – alternating current

Plug the red test wire in to this jack if you want to measure the inductance if your coil – note the H For Henries.

Dial setting for measuring the inductance of your coil (microhenries)

The black test wire plugs in here

The red test wire is plugged in here when measuring voltage

Amplifier •

The amplifier in the DCM is used to boost the power input to the coil. The amplifier of choice among coil machine builders is the QSC RMX1850HD. The HD represents “heavy duty.” The maximum power output is 1800 watts. The maximum output of contact and other frequency devices is approximately 2 to 10 watts. This amplifier is loaded with circuit protection electronics so the risk of overheating damage is reduced. It would be prudent to search for this amplifier online and find the best current price. Many times shipping is free. When searching you will find that many sites do not use the RMX in the name for the amplifier – just QSC1850HD. The cost of this amplifier represents about 36% of the total cost to build a DCM

These terminals must be connected together with a piece of 12 gauge wire.

.

This is a bank of small slider switches. Slide all to the OFF position (left) except for the 2 switches labeled “parallel input #4 and #5 to the ON position (right).

barrier strip (screws) The red wire from the signal generator cable is attached to to the top screw, the black wire from the signal generator cable is attached to the 2nd screw and a wire loop must be used to connect the 2nd and 3rd screws together. This mean that the 2nd screw down has two wires connected to it. .

Run 12 gauge wire from here to one of the terminals of the binding post mounted on the switch panel. The coil plugs into the binding post. Run 12 gauge wire from here to the first set of 5 resistors

Run wire from here to the second set of 5 resistors (the side closest to the amplifier). You can screw the plastic insulator out and fit 2 – 12 gauge wires in the hole in the shaft (note that the top black terminal will have 2 wires connected to it. The 2 red and other black terminals only have one wire connected there.

The input from a signal generator to the QSC185HD cannot be greater than 1.16 volts RMS (Root Mean Squared) or 3.34 volts peak to peak according to the manual. If you use a signal generator other than the Instek SFG 2004 model be sure that the lowest output is as low as possible. The Instek 2004 lowest output is .1Hz which means that the lowest voltage output is also very low. A better situation would be to have the lowest output be 0Hz which would mean that the lowest voltage output is also zero. RMS means that the entire sine wave is sampled and can be measured by True RMS multimeters. You can usually choose the voltage output of your signal generator - it can vary from some minimum value to as much as10v and is measured peak to peak which is not the same thing as RMS voltage. The peak to peak voltage is greater than the RMS voltage by a factor of 2.88. You cannot choose the minimum voltage output of your signal generator.

Switches You can use regular house wall switches used for lights, etc. - they require more space than toggle switches but they are much less expensive. I chose to use toggle switches to reduce the size of the switch bank on the front panel of my DCM and am very pleased with the result.

wall switch

Toggle switch

The toggle switches I used for this tutorial were purchased from Action Electronics. http://www.action-lectronics.com/switches.htm?zoom_highlight=toggle+switches#Standard

I used the heavy duty 20 amp switch # 30-305 for this project but used #30-310 for my first DCM. I recommend the #30-310 or the switch listed below which is the lowest cost switch I found online. http://www.alliedelec.com/Catalog/Indices/MfrLandingPage.asp?N=4294931389&Supplier=Carling_Technologies&sid=46C788005FB8E17F The part number is 683-0049. This is the same company where I purchased the capacitors.

This is the back of the switch panel. I used tape to apply the switch labels to aid in wiring. Since each capacitor array is labeled with letters B thru P, it makes sense to label the switches also. Since my DCM structure is a cart, this panel will be secured on the second shelf of the cart. An alternative to the cart is shown in the last section of the tutorial – a frame and panel cabinet.

This the front of the switch panel. Each switch should be labeled with the capacitance and the letter A thru P. The red and black plugs on the left are the binding posts where the coil is plugged in for use. A Word document on the CD called “cap switch labels” prints a set of labels for you. Shown are two banana plugs that will be soldered onto the ends of the speaker wires connected to the coil. Each coil has its own 15 feet of speaker wire and banana plugs. The binding post. The ¼” plywood switch panel ends up between the red and black plates shown on the right. The switches and binding posts are designed for panels up to ¼” in thickness or thinner.

Capacitors •

A capacitor is an electronic device that stores an electric charge to a certain level and then releases it. Capacitance, or the amount of current that is stored, is measured in farads or in our case with the DCM in microfarads (1/1,000,000th of 1 farad). The DCM uses 15 capacitor combinations of single capacitors or combinations of capacitors that are connected to 15 switches – altogether 26 capacitors are used. There are really 16 switches but one is not connected to any capacitors (switch A). The switches are labeled with the capacitance value of the capacitors connected to that switch and by letters A through P. A Microsoft Word document is provided on this CD that when printed will provide you with labels for your switches (a glue stick is a good way to stick the labels to the panel your switches are mounted on).

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Capacitors are used in the DCM to store and release electric charge which produces the alternating magnetic field in the coil. The capacitor voltage is 180 degrees out of phase with the voltage output of the amplifier and when these voltages are equal you have achieved resonance in the coil. This means that the two voltages cancel each other out which produces the magnetic field and resistance which results in the heating of the coil.

A resonating coil is necessary in the DCM which is the reason for using capacitors. Connecting capacitors together can be done in parallel or series connections. Imagine a train composed of many individual cars or units. The front of each car is connected to the back of the car in front – connecting capacitors in this manner would be a series of capacitors. Now imagine that two trains are next to each other on their separate tracks. Now if the front of a car in train 1 is connected to the front of a car in train 2 ( the backs are connected also) you would have created train cars in parallel – connecting capacitors in this way produces parallel capacitors. Adding the capacitance values of capacitors in series is different than adding them in parallel circuits. If you use the capacitors given in this tutorial you will not have to calculate capacitance values since they are given. If you decide to add additional capacitors to your DCM such as large capacitors to generate lower frequencies or very small capacitance capacitors to generate higher frequencies, you will need to calculate capacitance values.

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If you only use the capacitors given in this tutorial you can skip this slide, but if you put different capacitors in your DCM or are curious – read on.

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Adding capacitance of parallel capacitors is simple – just add them together.

•

For example: if you have capacitors of 16 μf and .062 μf connected in parallel, the capacitance of this array is 16.062 μf. Your label on the switch connected to this array of capacitors should be labeled 16.062 μf.

•

If you have capacitors in series – train cars in a line - the adding of capacitance values is done differently. For example: if you have 3 capacitors each of 3μf capacitance in series – the total capacitance is: Total Cap. = (1/3 + 1/3 + 1/3) = 3/3 or 1 μf The toggle switch connected to this series of capacitors should be labeled 1μf.

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• •

•

Why do I need to have some capacitors in series and others in parallel mode? The answer is that you need to have a list of enough capacitances to add together and be able to match any capacitance required by any frequency you choose. A DCM cannot actually produce all frequencies by turning capacitors on, just those between approximately 230 Hz +/- and 2000 Hz +/-. The +/- means that your coil’s inductance will determine how far above 2000 and below 230 you will attain. For example: If you choose to generate a frequency of 625 HZ you would need a capacitance of 7.619 μf with an 8.51 mh coil, but what if you only had 5 capacitors connected to 5 switches with capacitance values of 16, 8, 4, 2, and .1 μf. You would not have the right capacitances to add together to have a total of 7.619 μf. So capacitors are connected together so you can attain enough capacitance values that allow you to match almost any capacitance needed for the frequencies the DCM can produce. It would be possible and perhaps useful to expand the list with additional capacitors and switches to “fill in the gaps” of the list but when you actually use your DCM you’ll find that the capacitance list is very adequate.

So to answer the question again – you need a variety of capacitances so their values cover the range of the ones you need for your required frequencies. The list on the right is very adequate for a DCM. For example: Examine this list of the capacitances used in this tutorial for the building of a coil machine. If you choose a frequency that required a capacitance of 2.662 μf you would have to turn on the switches with capacitances of 2, .5, .122, .033, and .007 to give a total of 2.662 μf. You would flip the toggle switches F,H,J, L, and O to the up or on position. .

• • • • • • • • • • • • • • •

30 μf 16 μf 8 μf 4 μf 2 μf 1 μf .5 μf .25 μf .122 μf .062 μf .033 μf .015 μf .010 μf .007 μf .005 μf

B C D E F G H I J K L M N O P

Here is a photo of the front of a coil machine. Notice that there are 16 toggle switches each labeled with the capacitance of the capacitors connected to that switch. If you add all the switch capacitance values you get a total of 62uf. A frequency requiring a greater capacitance than 62uf cannot be done by using the switches. Instead you can use the A switch alone for any Frequency lower than about 230Hz that requires a capacitance higher than 62uf. This is the binding post where you plug in the coil

switches A - H switches I - P

Switch Labels – The CD contains a Word document titled “cap switch “labels” that will print a set of labels for your 16 switches

A no cap B 30μf C 16μf D 8μf E 4μf F 2μf G 1μf H .5μf I .25μf J .122μf

K .062μf L .033μf M .015μf N .01μf O .007μf P .005μf

Making capacitor arrays There are 16 toggle switches on a typical DCM and are each connected to single capacitors or capacitors in series or parallel connections. Toggle switch A is the only switch not connected to any capacitors. When it is turned on all the other capacitors are inactive. In the next slides we will build 2 mounting platforms for all of the capacitor circuits. These platforms are nothing more than two pieces of birch plywood that are held in an upright position on a shelf. This provides a large amount of surface area for spacing of the capacitors without needing very much flat surface area as in shelves. The picture on the next page shows the upright panels with all of the capacitors attached on the second shelf of the first cart I made. You could easily eliminate the cart and build a box or cabinet structure that could hold the capacitor panels. The most important feature is that the switches must be mounted on a ¼” thick panel so they can be wired to the capacitors. A panel for the switches could also just be supported by framing wood – the switch panel must be 1/4” thick to accommodate the toggle switches and binding post.

To start building capacitor arrays I cut two panels (15” x 9”) of birch plywood left over from another project. There is nothing special about this panel size except that everything fits on the 4 available sides and there is adequate space between all components.

Back of the binding post. The coil plugs in on the front (the other side) of this panel

This wire is going from the left terminal of the binding post to the negative output terminal on the back of the amplifier which is on the shelf below. The two panels are shown here. The far left panel has the 2 sets of resistors on the hidden side. This is a view from the back of the cart so the switches are all just to the left of the binding post

This is .062” rosin core solder and is a good size to use for this project. Shown is a 1 pound spool but much less is required to do all the soldering for a DCM. I got this spool at Radio Shack. Make sure that you get non-lead solder (which is tin and antimony).

Velleman Soldering Station Model VTSS5U http://www.elexp.com/sdr_ss5u.htm This is an example of an inexpensive soldering iron with temperature control from 374 to 896 F. A handy feature is the black tube for holding the hot iron when you are busy getting the next connection ready.

Cable ties and cable tie mounting bases (Home Depot and Lowe’s). You could eliminate these bases by simply drilling holes in the plywood panels and using cable ties to hold the capacitors in place.

In a setting with children or pets you might consider building a box so all electrical components are out of view. Some wires are not insulated such as the ones attached to capacitors and resistors. These are bare and electrified when the coil machine is in use plus capacitors store electric charge and may be dangerous to touch well after you turn the components off You may have to wrap protective insulating tape around these wires. A cart with exposed electrified wires would not be a good idea if children have access to the cart. The only items that gets warm are the two sets of resistors. None of the capacitors have gotten warm with use of the coil machine.

As many doug coil builders did before me, I used the standard 26 capacitors given in this list. I ordered them from Allied Electronics at www.alliedelec.com. The total order quantities and part numbers are given below. 1 - #225-5010 3 - #591-7045 1 - #591-7025 2 – #591-4205 3 - #591-4200 2 - #591-6085 2 - #591-6075 1 - #591-6175 1 - #591-6165 1 - #591-6160 1 - #591-6155 5 - #591-6150 3 - #591-6145 The list given on the next page shows the capacitors that will be connected to each toggle switch . I recommend that you do not dump all the capacitors out of their bags when the box arrives. Each bag is labeled with the part # and each capacitor is labeled with the capacitance but not the part #. I found it much easier to search through the bags for the part number – then remove that capacitor, search any others that belong in that connection – connect the capacitors, mount them to the shelf, panel, or whatever you are using and then go to the next array. The majority of the switches have only one capacitor in the circuit so the term “array” may not strictly apply as commonly used.

Switch

Capacitance

Quantity/connection

A

none

no capacitors used for this switch

B

30 μf

1 / one capacitor used

225-5010

C

16 μf

2 / 8 μf in parallel

591-7045

D

8 μf

1 / one capacitor used

591-7045

E

4 μf

1 / one capacitor used

591-7025

F

2 μf

2 / 4 μf in series

591-4205

G

1 μf

3 / 3 μf in series

591-4200

H

.5 μf

2 / 1 μf in series

591-6085

I

.25 μ

2 / 0.47 in series with

591-6075

1 / 0.015 μf in parallel

591-6150

1 / 0.1 μf in parallel with

591-6175

1 / 0.022 μf

591-6155

1 / 0.047 μf in parallel with

591-6165

1 / 0.015 μf

591-6150

J

K

.122 μf

.062 μf

Allied Elec. Part

L

.033 μf

1 / one capacitor used

591-6160

M

.015 μf

1 / one capacitor used

591-6150

N

.01 μf

1 / one capacitor used

591-6145

O

.007 μf

2 / 0.015 μf in series

591-6150

P

.005 μf

2 / 0.01 μf in series

591-6145

These capacitors can be ordered from www.alliedelec.com

In the next pages the capacitor arrays will be assembled and mounted on two birch plywood panels (each 9” x 15”). Since 2 panels have 4 sides, 3 of the sides are reserved for capacitors. I used “cable tie mount bases” (Home Depot) to secure the capacitors to the panels. For single capacitors I used the adhesive back to secure the mount base but where larger capacitors were involved, I used #6 x 3/8” Phillips screws to secure the mounting bases to the panels. An easier way to mount the capacitors is to drill holes through the panel and use cable ties. If you use a metal mounting panel you will need to use rubber sheeting to keep the metal capacitors from contacting the metal. Gene Dillman found considerable stray current in his metal cabinet but solved the problem by insulating the metal capacitors. These are two of the cable tie mounting bases. They have slots for the cable ties to pass through and up around the capacitors. The ties are 7 inch ties and are just long enough for all the capacitors used in a DCM. The mount bases have an adhesive backing but when mounting the larger capacitors there is some prying action when you tighten the cable tie and the adhesive releases. This prying occurs because two bases are used for the large capacitors so they can cradle in the gap between the two mounts.

This is the 30 μf capacitor. The dark strip of wood on the left edge of the panel is a cap of cherry that hides the edge of the plywood when this plywood was used as a shelf long ago.

This 30 μf (PART 225-5010) capacitor is the only one on switch B. I label all capacitors to avoid mistakes in wiring to the switches. Avoid pulling too tightly on the cable ties. The capacitors shouldn’t move around but make the tie just snug enough.

These capacitors for switch C, each 8 μf (PART 591-7045) will be connected together in a parallel circuit so they should be mounted near each other.

On the next page these capacitors will be connected in a parallel circuit

The 4 μf (PART 591-7025) capacitor for switch E has been mounted to the panel and above the 8 μf (PART 591-7045) for switch D will follow.

The short pieces of 12 gauge wire have their ends stripped of insulation and the spade connectors will be crimped on. These wires are used to connect the two capacitors in cap array C together in a parallel circuit.

Use this section of the crimping tool to secure the connector to the wire – be sure there is no wire insulation in the aluminum collar that will be crimped. Also be sure that the wire does not turn independently of the connector –if it does crimp It some more. Notice how flattened the yellow insulation is where the crimping pliers were used

The capacitors used in a DCM do not have plus and minus terminals. By connecting the top terminals together and the bottom terminals together you get a parallel circuit (even if you turned one of the capacitors 180 degrees and rewired it. Here the panel is lying flat and in the picture to the right it is upright on its edge – the way it will be mounted in the cart.

Here is the entire side of the first panel. There is no capacitor for switch A. Switch A is used for frequencies that require capacitances larger than 62μf which is the sum of all capacitors in a DCM.

These 4 μf (PART 591-4205) capacitors for switch F will be in a series circuit. It doesn’t matter which ends you twist together. Hold them as shown. Leave about ¾” of wire Is between the capacitor and where they cross. They will be twisted together with fingers so once you start the twist be sure to pinch the spot where the wires cross so the twisting doesn’t migrate down toward the capacitors.

They don’t all work out to be this neat but this one makes a good picture.

Trim the ends but not so much that the twist is loose. All of the twist connections like this must be soldered

Decide where you want to place them then attach mounting bases and cable ties or drill holes and use cable ties.

This series connection of 2 - 4μf (PART 591-4205) capacitor will be connected to switch F

For switch G three 3 μf (PART 591-4200) capacitors will be connected in a series circuit

Twist the wires together as before - place the array to determine the location of mounting bases. Using a marker to label helps when wiring the capacitors together. Its just another way to keep yourself organized

series

parallel

Capacitor array H two 1 μf (PART 591-6085) to be connected in series to switch H is shown mounted on the panel. Notice that the wire twists that will be soldered are all out where a soldering iron can be used very easily.

The capacitors for switch I involve a parallel and a series circuit. First connect two .47 μf (PART 591-6075) capacitors end to end. Use needle nose pliers to make a bend In each of the free wires so they are perpendicular to the two joined capacitors. Connect a .015 μf (PART 591-6150) to these free wires which results in a parallel connection I used pliers to twist these connections since the available wire for the parallel connection is limited in length.

Just a few more arrays on this panel will be enough.

Switch J is connected to capacitors in a parallel circuit. Connect a .1 μf capacitor (PART 591-6175) front to front and back to back to a .022 μf capacitor (PART 591-6155). They are shown here mounted to the panel.

F

H I

G

J

Switch K is connected to two capacitors connected in a parallel circuit. Connect a .047 μf (PART 591-6165) capacitor front to front and back to back with a .015 μf (PART 591-6150) capacitor. Don’t twist the wire so much that the capacitors get close together.

K

The second panel is finished. All the wires on the left of each array will be connected to their respective toggle switches. The wires on the right of each array and all other capacitor arrays will be joined together and go to one of the terminals on the binding post. The binding post is where the coil plugs into the system with banana plugs.

We are now working on the second panel (the third side for capacitors). This side will contain the remaining capacitors and the other side of the panel will contain the resistors. Shown is the capacitor for switch L. It is a single .033 μf (PART 591-6160) capacitor.

This is another single capacitor for switch M. It is a .015 μf (PART 591-6150) capacitor.

Switch N connects to this Single .01 μf (PART (591-6145) capacitor.

Switch P connects to this series of two .01 μf (PART 591-6145) capacitors.

Switch O connects to this series circuit consisting of two .015 μf (591-6150) capacitors. The switches are located to the right. Both panels will be mounted in a perpendicular direction to the back of the switch panel

Soldering capacitor arrays Soldering is easy and fun. Be very careful with the hot soldering iron tip since it would be very easy to melt a hole in the casing of a capacitor. Ventilation is a good idea because the flux in the hollow core of the solder wire vaporizes when you melt the solder. Vaporized flux damages the eyes and lungs. Once the soldering tip is hot, touch the wires to be soldered and melt some solder on the tip of the soldering iron. The solder flows by capillary action so to ensure that it seals the connection, heat just long enough until you see the solder appear to sink into the joint.

The soldering iron tip is under the twisted wire to be soldered. The idea is to get the solder melted and onto the twisted wire quickly. Heating too long can ruin components like capacitors.

This is a strip of solder coming directly from a 1 lb. spool.

Connecting the capacitor arrays to the switches Each capacitor array has been lettered. It would be wise to check each array (before soldering) to be sure that where a series circuit is needed you actually do have a series connection and not a parallel connection. I chose to use solid 12 gauge wire to connect the capacitor arrays to the switches because there is always enough left over from coil winding but you could use stranded wire instead. Stranded wire is much easier to use than solid wire since it bends so easily.

A wire is soldered to one end of each capacitor array and then goes to the bottom spade terminal of the respective switch. In the case of the large metal jacketed capacitors with spade terminals, a spade connector is crimped to each end of the wire so no soldering is necessary. The switches shown have 3 male spade connectors. Switches with just 2 are easier to use since you don’t have to figure which one is not used.

Here a spade connector is pushed onto one of the two terminals of the 30 μf capacitor for switch B. Each of the 2 terminals has 4 spade connecting spots. You can choose any of the spade ends but when we connect all the capacitors together later you must use the other terminal to connect a wire to. The grey wire shown goes to switch B so the upper terminal with 4 spade ends is the one we must use later. After all of the capacitor arrays are connected to switches the wire on the other side of each capacitor array are all connected together and will go to the binding post where the coil plugs in.

The 30 μf capacitor is connected to the bottom spade end of switch B.

You can choose any of the 4 terminals on these parallel capacitors to connect to the switch. I chose the one on the lower capacitor and the terminal back toward the panel. The grey wire is going to switch C. When we connect all the capacitors together later, the terminal away from the panel (on either capacitor must be used).

This wire from capacitor array C is connected to switch C.

Connecting capacitor arrays that don’t have spade terminals requires soldering directly to the capacitor wire. An easy way to do this is to use about 3” of a strand of stranded wire and wrap the copper wire going to the switch and the capacitor wire together. Its easy to solder the connection this way. Another way to make this connection is to wrap the capacitor wire around the thicker 12 gauge solid wire and then solder the connection

Capacitor array F is connected to switch F. You can connect all the other capacitor arrays to their respective switches but I recommend that you first do the operations on the next few pages. The reason is that finishing the capacitor to switch part is easy – just push the spade connectors onto the lowest terminal of each switch. The next steps require a lot of finger room and will prove to be easier if all the switch wires were not in the way.

To avoid photographs that were mostly masses of wires and clumsy to work around. I do not have the switches and capacitor arrays connected to their switches in the next several pages. The next step is to cut 31 four inch long pieces of stranded 12 gauge wire. Strip 3/8” of the insulation off one end of 16 of the pieces and crimp a spade connector to that end. Strip about 5/8” of the insulation from the other end of the 16 wires. Attach the spade connectors to the middle terminal on the back of each switch. Spread the strands into a fan to make the next step easier. The top-most terminal on each switch is not used. There is an alternative method for this wiring shown in the last section of this tutorial.

Take the remaining 4” sections of stranded wire and strip 5/8” on insulation off of both ends. Spread the strands into fans as shown above.

Take 2 of the wires you just stripped and fanned and place them with the 4” piece of fanned wire connected to switch H (top left on the back of the switch panel). You will be twisting three pieces of wire together with your fingers. The fan shape make twisting easier.

Here two of the pieces of wire and the wire attached to switch H are twisted together. Don’t use pliers to twist since many of the fine strands may be broken. It is sufficient to use your fingers. Use an alligator clip or two to hold the three wires in place for soldering.

The connection has been soldered. When the solder cools use a red wire nut to cap the connection. The stranded wire that is almost vertical in this picture will be twisted with the wire immediately behind it and another loose piece of wire. What we are doing here is using the loose pieces of wire to “jump” from one switch to the next. In the end all switches will be connected together. The piece of wire pointing to the left coming from the soldered connection will be twisted with the wire below it and a loose piece of wire.

Keep connecting the set of wires until you get to switch A. There are just two wires to twist and solder for this switch. All of the twisted connections should be soldered and capped with wire nuts.

This photo shows the detail of switch H. Notice that the wire nut has two “jumpers” which allow you to continue across the top row of switches to the right to switch A and down to the bottom row of switches to the right to switch I. When you get to switch I do not solder until you see the next page.

When you get to switch I add in about 9” of stranded wire (I used black so you can see it in the picture. This black wire will be connected to both set of resistors

switch I

Notice the grey wires that are soldered to the bare copper wire that connects a set of resistors. The grey wires go to the left and are attached to the black wire. The black wire goes behind the wood panel to the wire nut that leads to switch I as shown in the picture to the left. The above resistor panel is not in the picture to the left – it was added to show how the resistors connect to the switches. Building the resistors sets is discussed in the resistors section.

The grey wires coming from the left side of both resistor sets go to the black wire and then to the wire nut at switch I.

The other two grey wires go to the right and go the back of the amplifier. Notice they are soldered onto the bare copper wires connecting the right sides of the resistor sets.

Connecting all of the capacitor arrays

Notice how grey wires go from a terminal on a capacitor to the switches. Also notice that grey wires now attached to the other terminal go back toward the left. The wires will be connected together and with “jumpers” will be connected to all of the other capacitors.

Here are the rest of the capacitors on this panel showing the grey wires going to the left. The top two capacitors labeled C are actually identical in size. The photo was taken at an angle which suggests that the top capacitor is larger. Notice that the wire going to switch C is connected to a different terminal than the wire going to the left. Both of these wires could have been attached respectively to the other C capacitor at the top.

A large blue wire nut secures all of the capacitor wires. Notice that a “jumper” wire goes to the left and through a hole to connect the other capacitors on the other panels. An extra wire is joined to the blue wire nut and goes to the binding post where it will be soldered. The wire insulation on the end of this wire is stripped so the bare end can be wrapped with a strand of copper wire and secured to the post for soldering.

Grey wires were soldered to the ends of the capacitor arrays and twisted with electrician’s pliers and will be soldered. The wire to the lower left is a “jumper” that will connect with a group of capacitors mounted on the panel to the right. Again notice that the wire on the other side of the capacitors will be connected to their respective switches but are not yet connected in this picture This picture shows the 3rd panel of capacitor arrays – the other side of this panel is where the resistors are attached.

There are too many capacitor arrays on these two panels to twist all the wires together so I made three bundles of wires connected by “jumper” wires. The arrow points to the “jumper” that is already connected with the wire nut to all the capacitor arrays on the panel to the left. The next page shows the 3 bundles.

•

The

There are 3 jumper” wires in this picture. The wire bundles with grey wire nuts were composed of fewer wires so required a smaller wire nut. See an alternative way of connecting the capacitors together at the end of the tutorial on the “New and Alternate Ideas Section. The unseen side of this panel has all of the metal jacketed capacitors on it. The blue wire nut connects all of those capacitors together.

This is the wire nut connecting all the metal jacketed capacitors – the “jumper” wire connects this panel of capacitors to all the other capacitors.

Resistors

There are 10 resistors in a DCM. They are connected in two groups of five resistors each. The wires coming out of a resistor are not quite long enough to twist all five resistors together and still have space for cooling around each one so I mounted each one on a cable tie mounting base.

After 5 resistors are mounted and strapped down, strip a length of solid 12 gauge wire of insulation and wrap about ½’ of each resistor wire around the solid copper wire. Do the same thing on the other side of the resistors. Each resistor could easily be held in place by drilling holes and using just cable ties.

The resistors on the left have been connected to each other on both sides. Mount the remaining 5 resistors on mounting bases and connect them together also.

Here are the 2 sets of resistors. The resistor wirecopper wire connections should now be soldered.

Choose the side of the resistor sets that is closest to the back of your QSC1850HD amplifier. Two solid copper wires must be connected to teach resistor set and one must go to the Channel 1 Minus output terminal and one must go to the Channel 2 minus output terminal on the back of the amplifier. Since my DCM is completely contained on a cart, I had to drill a hole in the shelf that holds the capacitor arrays and resistors to allow these wires to pass down to the first and lowest shelf to the amplifier. The two copper wires are hard to hold in place while soldering since you will have a roll of solder in one hand and the soldering iron in the other. Use one thin strand of wire to wrap the two together and then solder the joint and all the copper wire-resistor joints.

It doesn’t matter which set of resistors is connected to the amplifier Channel 1 minus output terminal. Connect the other set of resistors to the Channel 2 minus output terminal. Here are two copper wires that lead to the amplifier channel 1 an 2 minus output terminals. The wiring for the other side of the resistors is discussed in the section on Capacitors.

One set of resistors should be connected to Channel 1 output. The other set of resistors should be connected to Channel 2 output.

Wave/Signal Generator Many people wonder how a DCM can pulse a magnetic field at a given frequency. It’s easy – you choose! A DCM has as an integral part, a wave generator but you must purchase a wave generator that produces low frequencies. – in the Hz range (for waves such as 306 Hz, 432 Hz, 625 Hz, 2112 Hz). A short online survey of wave generators will quickly show you that most produce waves in the mega Hertz (MHz) millions of waves/second and many produce Giga Hertz (billions of waves/second) frequencies. A wave generator such as these will not be compatible with a DCM. You must have a wave (sometimes called a signal or audio) generator that emits very low frequency waves - as low as you can go toward zero waves per second. The Instek SFG-2004 generator produces waves down to .1 Hz (waves per second).

This is a BNC jack – the cable supplied with the generator has a BNC connector on one end And alligator clips on the red and black wires that split from the main cable. You can change the clips to fork connectors that fit under the screws on the back of the amplifier if you choose

This is the Instek SFG 2004 signal Generator..

Coil Stand •

I designed a coil stand that holds the coil off the back of the stand about ¾ inches for better cooling. There are four short 1 ¼” long dowel pieces glued in ½” deep holes. Each of these pieces has a ¼” hole drilled through it so the coil can be strapped down to these support pillars with 4 cable ties. The weight of the coil is further supported on 3 dowels that are 3 ½” long and glued into ½” deep holes (so 3” of each dowel sticks out of the back of the stand. This dowel length will accommodate coils that are as wide as 2 ½”, which is wider than the vast majority of coils used in coil machines. The coil shown is an 8.51 mh coil. The stand is made of red oak. The base is 1 1/8” thick and the tilted back is 7/8” thick. The angle between the back and the base is 14 degrees.

Cutout for handle allows coil to be moved but not abraded by constant handling. Cutout was made by drilling overlapping 1” holes with a Forstner bit with a drill press.

The cable tie goes through the pillar and around the coil – there are 4 pillars holding the coil off the back

The coil rests on three 1 inch diameter dowels in addition to being strapped to 4 pillar supports with 4 cable ties. The two bottom dowels are really the only ones needed for support.

Top support pillar

Bottom support pillars

The top right shows that two pieces of red oak have been glued together to make a wider piece for a coil stand base. The dried glue is shown along the glue joint. I use polyurethane glue exclusively. The wood must be slightly dampened to activate the glue but when it cures in a day its very strong.

The slanted blades shown (an adjustable dado cutter) consists of two blades that rotate around a wedge that tilts one blade so grooves (dadoes) of various widths can be – up to 7/8”. The saw is tilted 14 degrees to give the tilted dado. This helps to move the center of gravity of the 9 lb. coil backwards and stabilizes the stand

A spindle sander is great for cleaning up the insides of cutouts. I drilled 1” diameter overlapping holes to make the cutout. This is the vertical part that holds the coil. Here it is being planed so it fits into the slanted dado groove

The 3” radius curves have been cut of a bandsaw for the edges. The piece on the right is the base and the piece on the left is the upright

I could do without the sanding part but there are parts for 3 coil stands here and they all need a lot of sanding.

The 4 one inch circles will be drilled 1/2” deep with a 1” diameter Forstner bit. One inch diameter and 1” long dowel pillars will be glued in these holes for the wire coil to sit on.

The 4 dowel pillars have a 1/4” hole drilled so a cable tie can be put through the hole and around the wire coil. This straps the wire coil to the coil stand. Be sure to drill the hole before the pillar is glued in its hole and be sure to turn the pillar in such a way that the cable tie will go through the hole and around the wire coil without twisting.

The other 3 one inch holes are for longer dowels to support The weight of the wire coil. The coil for this stand is 1 ¾” thick and the holes are 3/8” deep so the dowel supports end up about 2 3/8” long (they are slightly longer than the coil is thick).

All dowels are glued in place.

The wire coil is strapped to the 4 short pillars with cable ties and the wire coil sits on the 3 longer dowels. A more universal stand would be to eliminate the long uppermost dowel. Coils of different sizes could then just sit on the two lower large dowels.

Three glued stands. They will dry overnight. The cured glue usually squeezes out and must scraped off with a sharp wood chisel. I use one coat of a tung Oil..

After removing any glue (with a narrow, sharp chisel) that squeezes out around the dowels, the stand is sanded and coated with tung oi lfinish. I let it dry for a day and then mount the coil with cable ties that pass through the short dowels and around the coil.

Here the cable tie has been pulled tight and the end has been trimmed.

This is one of the 15’ long speaker wires that will attach to the coil on one end and to a banana plug on the other end. It has been stripped of its Insulation (about 1/2”) and twisted around one of the solid copper wires of the coil. An alligator clip is very handy for holding the two wires while they are soldered.

The connection has been soldered. Cut off any of the stranded wires that stick out and trim the length of the solid wire if it sticks out. Use a wire nut to insulate the connection.

This is a finished coil stand with an 8.51 mh inductance coil. The coil’s dimensions are 2” wide and 1 ½ inches thick. This section on building a coil stand is not intended to show the best way to support a coil. The intent is to generate ideas when one way of supporting a coil is shown. This design however is especially nice to hold in your lap while sitting.

Connecting the speaker wire to the banana plugs

Unscrew the plastic insulator from the plug. A small adapter (not shown) was screwed into this plug in case the user wanted to solder very thin wire Into the plug – just discard this part. These plugs were purchased from http://www.elexp.com but many suppliers have Them.

I used regular pliers to hold the banana plug. To hold the pliers in a closed position without squashing the tip portion of the banana plug, I used masking tape on the handles. Strip about 3/8” of the clear insulation off the ends of both wires and be sure to put the red and black insulators onto the wires before soldering.

Hold the flat bladed tip of the soldering iron against the threaded end of the banana plug. It will be hot enough to melt solder in about 30 seconds. Put the end of the solder into the hollow end of the plug and almost fill it with molten solder. Put the soldering iron down and quickly pick up the end of the speaker wire and insert the well twisted stranded wire end into the molten solder. Hold it there for a few seconds until it is secure. If you fill the end of the plug with too much molten solder, it will run out and into the threads of the plug. You might have to file the threads off if the solder is too thick. Taper the end of the plug with a fine file so the plastic insulator can be twisted on without stripping the threads inside. It’s a lot easier to not fill the hole with too much solder.

The color of the insulated plastic barrel has nothing to do with the color of the wire in the above picture. The other end of the speaker wires will be connected to the two wires on the coil – do it wrong and there will be a huge explosion – just kidding – just connect them.

Doug Coil Machine on a Cart I designed a cart for my DCM so all components could be in one place and also be portable. Since the QSC1850HD amplifier is the largest part and heaviest (50 lbs.), the cart’s dimensions are based on it alone. The lowest shelf holds the amplifier, the second shelf contains all of the capacitors, resistors, and wiring to the switches. The top shelf holds the coil stand, the multimeter, the signal generator, a stop watch, and a printout of the frequencies and switches. The next pages will show the cart but not all the woodworking details. The legs and shelf supports (stretchers because they hold the legs in place) are all made of red oak. The shelves are ¾” oak-veneered plywood. The wheels are 2 ½” diameter rubber swivel wheels (Home Depot). I am presently designing a model that will eliminate the cart. The electronics will be in a frame and panel red oak cabinet that will fit exactly on top of the amplifier and will itself be about 7 or so inches high.

The 16 switches are here

The binding post is here

The bundle of wires goes through a hole in the top shelf to the signal generator and the multimeter The 2 white wires go to a signal generator + and – output terminals, they come through the hole leading down to the amplifier

The side panels have cutout hand-holds. I The cart seemed like a great idea because it is mobile but it turned out to be in the way most of the time. The last section of this tutorial has some details of an oak cabinet that has the same footprint as the amplifier.

The two sets of resistors are here One of the black wires is the power cord for the signal generator on the top shelf. The other black wire and the red wire are the test leads from the multimeter located on the top shelf. The red and black alligator clips are shown attached to a set of resistors.

This is the cart with the top shelf removed so you can see the electronics shelf. This is the first DCM I built and is not the one photographed for this tutorial but is virtually identical. You can easily see the three panels of capacitors. If you go through the tutorial a few times you will recognize everything that is here.

Each vertical plywood panel is held upright by twos ¾” x ¾” X 19” wood strip on each side of the bottom of the panel. They are just screwed to the shelf. An additional screw or two could be placed horizontally to the shelf through the wood strips and into the panels. The vertical panels are not attached to anything at their tops

New and Alternate Ideas Section 1. The twisting of capacitor wires together with wire nuts is messy looking. It certainly works but here is an idea for a neater look. Radio Shack (and many others) sells terminal blocks. You will need 3 if you have 2 upright panels containing capacitors and resistors but just 2 if you have all of your capacitors on one surface (shelf). The screws across from each other on a terminal block are connected electrically but not to any of the other screws. Here is a way to make all the screws have continuity. The jaws of wire stripping pliers have grooves on the jaws that grip very well. Strip about 2” of the insulation from some 12 gauge wire. Use the pliers to grip the wire about 1/8” from its end. Turn the pliers to bend the wire into a small loop. When you have a 180 degree bend use the pliers to squeeze the bend into a tight U-shape. Make sure the ends of the U are just far enough apart to fit between 2 adjacent screws on the terminal block. You may have to adjust the shape of the U with the pliers. If your terminal block has 8 sets of screws you will need 7 U-shaped bends of wire. The pictures on the next page illustrate this idea.

This is a terminal block. Each set of 2 screws between the black dividers are connected together with a metal plate beneath the screws. To get all the screws connected together you need to use jumpers or bridges.

Here a loop of wire was formed with the stripping pliers and then the loop of wire was squeezed into U-shape.

Every screw on the top row can have 2 wires attached to it (on its left and right sides). Notice the two end screws on the bottom row – 1 more wire can be attached on each side of the terminal block for a total of 18 wires. The black plastic is a good insulator so the block can be screwed down to a mounting surface.

The 4 wire nuts in this picture connect the wires from 15 capacitor arrays and 3 jumper wires to connect the capacitor arrays together - it makes for a busy look. Three terminal blocks (one for each capacitor panel) would be mounted on the panels and each of the wires going to the wire nuts would instead go to the terminal blocks. Only 2 jumper wires would still be required to get from panel to panel. If all capacitors and resistors were mounted on one flat surface – only 1 terminal block would be needed. The 8 screws could each accommodate 2 wires from capacitor arrays plus the ends of the block containing the copper loops has 2 spots for 2 additional wires. There are actually 18 places wires can attach.

2. Most people do not have complete wood shops for cabinet making. Here is an idea for a simple structure but not in (because the electronics are exposed) a household with children or pets unless you could restrict access to the coil machine when it is in use. To look balanced, the base of this structure should be same size (or less) as the length and width of the QSC 1850HD amplifier since it would sit on top of the amplifier. Short feet, chair feet protector buttons, or small blocks of wood could be attached to the base to allow for air circulation above the amplifier.

The ¼” thick panel should not be thicker because the switches would not be long enough to secure the threaded collar to tighten them onto the panel.

A few screws will hold the panel to the base.

switches and binding post go here capacitors and resistors This base sits on the amplifier

3. Another idea is to eliminate the extra wiring with jumpers and wire nuts to connect the switches together. A simple solution would be to use #30-305 switches (the switches used in the tutorial #30-310 could be used as well) which have 2 terminals and on/off switch action. On pages 82-85 a wiring method is shown to connect all the switches to each other with the red stranded wire. All of this could be eliminated by mounting one terminal block on the back of the switch panel (and use copper U-shaped jumpers to connect all the screws on the 2 row, 16 screw terminal block together) . Use a length of solid 12 gauge wire with a spade connector on its end to connect to the bottom terminal of the switch. The other end of this wire would be connected under one side of a screw of the terminal block. Do this operation with every switch so that 16 switch wires would go to the terminal block. Two additional wires would have to come out of the terminal block and go to the two resistor sets to connect them into the system.

A much more compact DCM than a cart model is the frame and panel cabinet model. The cabinet sits on top of the amplifier so the footprint is as small as possible. The main disadvantage is that the space inside the cabinet for capacitors and wiring is much more limited so the capacitor and resistor layout is more important since space cannot be wasted. I decided to place the resistors on a small vertical panel.

vertical resistor panel

terminal blocks instead of twisting wires and wire nuts

This is the back of the switch panel (switches are #30-310 – see the Word document “Coil Machine Parts List” on the CD for the source for the switches - with 3 spade terminals). If you would mount a terminal block above the switches you could simply attach a wire to a switch’s middle spade terminal and attach the other end of the wire to the terminal block. To do this with all switches would connect all of them electrically. Switch #30-305 only has 2 terminals so you would connect the wire from the correct capacitor array to the bottom spade terminal. The wire going to the terminal block would attach to the switch’s other terminal. A terminal block in this situation would save a lot time (no twisting of wires and no soldering). Since the switch panel is 1/4” plywood you cannot attach the terminal block with screws. One way around this problem is to glue a strip of wood about the width of a terminal block but about 1/2” longer onto the panel. You will need to clamp the wood strip and let the glue dry overnight. Place the terminal block on the wood strip – mark where the holes are located and drill small holes in the wood strip and attach the terminal block.

I would be very pleased if anyone who invents an improvement in design or finds an easier way to do any of the things shown in this tutorial would email the ideas to me. Especially important would be structures to house the electronics portion of the Doug Coil Machine, coil stands, wiring improvements and I will incorporate them into this tutorial either in the main body or in this section. The idea is to make the construction of this coil machine as clear and as uncomplicated as possible for anyone to build. Your name will be attached to your ideas.

Encouragement Page That’s all there is. I hope everyone who views this tutorial will do it more than once because it will become more and more clear as you begin to understand initial points. Don’t give up and say I can’t do it because you can start and finish a Doug Coil Machine. Just think for a second that this might be the best accomplishment, as far as making something is concerned, in your entire life. I cannot believe that anyone who built a Doug Coil Machine would feel bad about it afterward – you will not only feel good, but the most important point is that you will be helping yourself. If you have questions, I would be most happy to hear what you need to know. Thanks for your interest, John Stolar [email protected]