Build your own Doug coil machine

8/7/2019 Build your own Doug coil machine

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Build your ownBuild your own

Doug Coil MachineDoug Coil MachineEasy to follow steps with clear explanations andEasy to follow steps with clear explanations and

numerous photographsnumerous photographs

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

And Lyme victimAnd Lyme victim



D edicationD edicationIt 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.D oug MacLean designed what is now known as the ³ D oug Coil Machine´

and showed what could be achieved with ingenuity and amazing curiosity.His discoveries are admired by many thousands who appreciate hiscontributions to all of us.

John Propster designed the current model of the D oug Coil Machine andtouched lives that he could not possibly imagine.

Our gratitude to these exceptional individuals is well deserved.

Thank you, D oug and John, for making a difference.



D isclaimer pageD isclaimer page

Coil machines are not approved for the treatment of any disease or condition by theFederal D rug Administration or any other government, public, or private agency.

Coil machines are not recommended for use on humans since the effects have not beenfully researched and understood.

Women who are pregnant and anyone having a pacemaker should not use a coilmachine.

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. D o not substitute the use of a coil machine for competent medicaladvice and counseling.

It should be understood that human biological responses to coil machines are not fullyknown.

It is understood that the user is responsible for experimental investigation and accepts allresponsibility for the use of this device.

The user cannot hold the author of this coil machine tutorial responsible for anyconsequences that may result from the building of this device.



IntroductionIntroduction

This presentation will organize the construction of a D oug coil machine(D CM) in a logical series of steps and will provide detailed explanations andillustrate the steps with many sequential photographs of a D CM being built.A person with no electrical experience will be able to complete this projectsafely 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 D oug Coil Machine. The purpose for producing such a thing isto provide some aid to my fellow Lyme-infected sufferers - its my chance in life to do something good for alarge number of people, most of whom, unfortunately, I will never meet. Not many people get a chance likethis so for this reason, this C D 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 ContentsTable of ContentsP ages

5 Schematic of a D CM6 - 8 Tools and Materials9 - 14 Operating a D CM, Shutdown Procedure

15 - 20 Coils21 - 40 Coil Winding D evice, soldering speaker wire to the coil41 - 43 Measuring your Coil¶s Inductance44 - 47 Multimeter 48 - 50 Amplifier 51 - 54 Switches55 - 63 Capacitors64 - 84 Making Capacitor Arrays85 - 101 Connecting the Capacitor Arrays to the Switches

102 - 106 Resistors

107 - 108 Wave/Signal Generator 109 - 122 Coil Stand123 - 129 D oug Coil Machine on a Cart130 - 138 New and Alternate Ideas Section139 Encouragement Page



Schematic of a D CMSchematic of a D CMsignal

generator

QS C1850HD amplifier (back) Channel 1_

+

amplifier output

Channel 2+_

volt meter

amplifier input

barrier strip(screws)

Channel 1 & 2inputs

Mode Switchesall are off (pushsliders to the left)except for #4 and#5 parallel inputs

caparrays(2 areshownthereare 15)

all other switches

all other switches

switchA

coil

12 ga..speaker wire

double binding post

connect top & bottom terminalswith 12 gauge wire loop

2 sets of 5 resistors

each

wire nuts connecting2 coil wires and speaker

wires

no caps onswitch A

The Instek SFG 2004 signal generator comes with a cable that plugs into theBNC jack on the bottom right of thegenerator and alligator clips on the other end. I cut the clips off and attached forkconnectors. The red wire should beattached to Channel 1 + and the blackwire to the Channel 1 ± terminals.Use a small wire loop to connectthe ± terminal andthe ground terminals together.

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



Tools and MaterialsTools and Materials

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



W ire stripper and cutter This tool is specifically made for 12 gaugewire. Other sizes are available but this maythe most important tool for this project soto avoid much wasted time ± get the 12 gaugeone.

Electrician¶s pliers

W ire nuts

Blunt ends allowfor twisting 3+ wirestogether



Soldering iron with temperature control and hot ironrest stand. Soldering is mostly done to securecapacitors together in a D CM. Cost is about $16.Check http://www.elexp.com for parts and tools

Soldering iron ± no temp. control and no rest stand

Wire connector crimping tool. This does a much better job thanregular pliers. Notice the bare wire inside the connector- theinsulation should be stripped so the tinned metal sleeve is crimpedaround bare copper wire. Get female connectors that are madefor 10 or 12 gauge wire.



Operating the D CMOperating the D CM

Knowing how to operate the D CM before building it may help people understand howthe components work together.

1. Place the coil so the hole faces you. It can lean on something sturdy or can hangwith ties to the back of a wooden chair, etc. It can get hot (well over 100 F) so besure to keep plastic items away from the coil. Electrical tape can melt if used to holda coil together or to hold it in place while in use. D etails 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¶smagnetic 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 jackson the D CM.

2. Turn the multimeter on and set the dial for V ~ (volts AC current) and use the RANGEbutton to set the units shown on the LC D screen of the meter to V ~ (not mV which ismillivolts). 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 (withalligator clips to hold the test leads in place) must be placed at both sides of a set of 5resistors (see picture on next page) that are soldered together. Be sure to plug in theblack test lead wire into the black jack (or Com) in the multimeter and the red testlead in the red jack that has V next to it.



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

This is how the meter should be setup to operate theD CM. Notice the positions of the red and black testleads. The dial is pointing to V~ and the ³Range´ buttonwas pushed to get the decimal behind the first zerosince the meter will read 1.500 volts when the D CM is inuse.



1. Turn on the signal generator and input a frequency such as 432 and pushthe Hertz button. Push the ³Wave ³ button to get the curvy sine curve icon.Push ³Shift´ and ³8´ to get the -20db icon. This subtracts current from theinput to the amplifier so the ³Ampl´ knob is much less sensitive and can beadjusted better. The generator is now outputting waves of the frequency youchose. You could check this by setting your multimeter dial to Hz and usingits 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 themachine is operating.

2. Turn on the amplifier with its rocker switch ± be sure that the 2 volume dialson 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 requiredcapacitance for the frequency you chose. (See the section on capacitors)

4. Turn both amplifier dials clockwise to the maximum position



5. Turn the ³Ampl´ knob up on the signal generator until the reading on theLCD multimeter display reads 1.5 volts. The coil machine is ready to use. Ithums fairly loudly. The coil heats up in time so if the phone rings ± let itring. If the red clip lights on the amplifier ever go on turn the ³AM PL´ knob CC W to lower the current.

The coil can get hot so it should be on a stand that you can hold or get closeto. It is recommended that you have a fan blowing on the coil for coolingpurposes and for ventilation. The plastic insulation on the wire in the coilcan emit fumes if the coil exceeds 235 F. so be sure to be in a wellventilated room ± a closet would not be suitable.

6. When you finish with one frequency and want to choose another, turn the³AMPL´ knob off and both gain knobs on the amplifier counterclockwise to

zero.D

on¶t change capacitor toggle switches when the amplifier volumedials are anywhere other than zero. This prevents overloading thecapacitors with electric current.





Shutdown ProcedureShutdown Procedure

Shutdown is simply the reverse of the steps you do to operate the D CM

Turn the ³AMPL´ knob off, Turn the amplifier gain knobs off (counterclockwise all the way)

Flip capacitor toggle switches to off (in the down position) however theswitches can be left on but it is advised to check that the correct switchesare 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 thefront of the amplifier will be warm or hot at first. Push the rocker switch tooff after the air feels cool.



CoilsCoils

Insulated copper wire coils are used to produce magnetic fields thatchange the positions of the magnetic poles at different frequencies.For instance at a frequency of 432 Hz the magnetic poles changeposition 432 times per second

Coils differ from one another in various ways such as

1. different size (gauge) insulated wire, D CM coils use 12 gaugeinsulated solid copper wire. The copper is 2mm in diameter andwith the insulation it is 3mm in diameter.

2. different thickness of wire insulation3. 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 givenvolume, the higher the coil¶s inductance will be.



An electrical measurement that is important for building a D CM is theinductance of the coil. Inductance for our purpose is not important tounderstand in depth but a short definition is that inductance is the ability of acoil carrying an electric current to resist a change in the current flowingthrough the coil. Another way to understand inductance is that it is ameasure of the amount of copper in a cross section of a coil if the coil couldbe cut across the wires. Coils that have an alternating (the current travels ina wave form) electric current running through them produce an alternatingmagnetic field. Moving electric current (charged particles) automaticallyproduces a magnetic field. Even hot gas becomes charged and produces

very strong magnetism due to movement of the gas as in the surface of thesun.

The reason Inductance is important is that it is related mathematically tofrequency and capacitance. If we know two of these values we cancalculate the third one.

For example when make a coil you physically measure its inductance withyour multimeter. This gives you one of the values needed. You choosewhat frequency to generate with your signal generator ± so now you havetwo of the values. A calculator program supplied on this C D will allow youto get the desired capacitance so you can turn on the correct capacitors togenerate an alternating magnetic with your coil.



Most coil machine builders have one coil. This coil with an inductance of 7to 8 millihenries (mh) will easily produce alternating magnetic fields fromabout 20 pole reversals per second to about 2000. The unit of frequency isHertz where 1 Hertz is one pole reversal per second. To have higher frequencies you will need a coil of lower inductance approximately in therange of 4 to 5 mh. Overheating of the amplifier is the result of attemptingto generate higher frequency with a high inductance coil (you should use alow inductance coil for the frequencies over approximately 2000 Hz.You can try all of this out on the calculator by typing in various frequenciesand inductances to see how capacitance changes

How do you make a coil of lower inductance? less wire - accomplished byless width and thickness of your coil (assuming you still have tightwindings).

For example ± a coil I wrapped with 12 gauge solid, insulated THNN wire(available in 500 foot spools at all Lowe¶s and Home D epot stores) thatmeasures 2 inches wide and 1.5 inches thick, wound very tightly, measuredan inductance of 8.51 mh. This coil has 12 layers of wire in the 1.5 inchthickness and 16 rows of wire in the 2 inch width. It contains approximately425 - 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 1.5ín thickness and 1.75´ in width has an inductance of 7.20 mh. This coil has 15layers 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 coilwrapped with the same gauge wire on the same form but this time the widthand thickness both are 1 3/8´ now has an inductance of 2.98 mh. This coil has11 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 istoo 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 tohave only one coil. If your coil comes out slightly higher or lower, it doesn¶tmatter significantly because the capacitors you will switch on for a particular frequency will change with the inductance of the coil you make. That isprecisely why this tutorial cannot supply you with a list of capacitor switches touse for a given frequency you wish to generate since your personal coildetermines this factor.You don¶t have to calculate anything since there is a calculator programon this C D 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 mHsymbol (Henry is the unit of measure for inductance).Also notice that the red test lead is plugged into thefar left red socket labeled with an H. The coils are notconnected to a coil machine in these pictures. Themagnetic field is very strong in the hole area of the coiland would produce heating in any metallic objectplaced there ± your meter would be ruined.



Coil dimensions and InductanceCoil dimensions and Inductance

(all coils have 6´ diameter holes and are wrapped with 12 gauge THNN solid copper wire)(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. Thespool 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 hasan extra row. W ire tension during winding has more of an effect on the number of layers than on the number of rows so this is oneof those things to ponder( I suspect that if wraps nestle in between the wire wraps below them throughout the coil you will get ahigher inductance coil than if layers of wire sit exactly on top of the wires in the layer below). S ome 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 thewire 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 D eviceCoil Winding D eviceThere are many good ways to wrap insulated solid copper wire tightlyenough to make a good coil. I wrapped 50+ coils in seven months with thedevice I made and of course the last one is better than the first. I decidedthat I needed firm sides on the form I would wrap the wire upon. Thatdecision eliminated anything that would flex with pressure so I used ¾´ thick(actually .707 inches thick and not .75´) birch plywood. A series of picturesillustrating 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 birchplywood. 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 thelargest circle and through the center point and then drew lines 15 degreesapart (I used a plastic protractor) from the center of both circles out to the 6ćircle. Thirty 3/8´ holes would be drilled at these15 degree intervals alongthe inside of the 6´ circle. It is necessary to only draw the circles and lineson one of the plywood pieces since they will be taped together so the drillingof 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 8 areas where slots wil l be cut to hold the cable ties thatwill eventually hold the wire coil together. It¶s a nice way to have theties held in place while winding wire. The birch plywood is stainedbecause it was a shelf from a large TV cabinet I made. I got a larger TV and didn¶t need the cabinet any more.

These are 15 degree spaces on the 6ćircle. A 3/8´ hole will be drilled insidethe 6 inch circle at the end of each line. Thedrilled holes will all be inside the 6´ circleand not cross over into the space between the6´ and 9́ circles. The center of each3/8´ hole should be on the lines pointed to bythe blue arrow.



The holes are completely inside the 6´ circle.The dowels that are placed in the holes will formthe surface that the wire is wound upon. Note thatthe disks are taped together so they can be drilled

together.

The dark holes are charred wood caused bya dull drill bit. Its easy to see what a sharpdrill bit does on the other holes. The sharp bitI used is a brad point wood drill bit. It has a pointedtip which makes it easy to see where the center of thehole 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 jointhe 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 thewinding spool and the surface of the disk on the left willbe on the inside of the winding spool. The arrows show thealignment of the disks when they were taped and drilled.



e

The grooves were cut with a radial arm saw but there are other waysto cut the grooves ± but none as easy as with a radial arm saw. Asharp chisel would work but it would be slow. The blade is raisedotherwise I would cut the disk into pieces. Since the saw blade teethare 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 grooveslightly large is better than a groove that is too narrow. The depthof each groove is slightly deeper than a cable tie is thick. Noticehow these grooves are between the holes. This is so the cable tiescan slide easily in the grooves.

D rill a 5/8 inch hole for a dowelor iron rod so the winding spoolcan easily turn.

I highly recommend oak 3/8´ dowel rods (fromHome D epot). The are tough and will take the hammeringrequired to assemble the winding spool for winding acoil and taking it apart to get the wire coil off. I waxedthem with bees wax to make them easier to use. Thedowels are 3 ½´ long. This length allows them tobe firmly in each disk and to have 2´ of spacebetween disks for winding a 2´ wide wire coil. If you want to wind wider coils ± make the dowelsrespectively longer.

beeswax



The winding spool is assembled. I recommend driving the dowelsInto a disk as it sits on a firm surface. A rubber hammer will not dentand destroy your wood disks and dowels like a metal hammer will soondo. After all the dowels are in the first disk as shown to the left, it is a littletricky to get the second disk started onto the dowels. If you slightly tiltthe second disk you can get a few dowels started into the holes of thesecond disk and just slowly work your way around the perimeter. Youwill have to use your fingers to force some dowels into alignment. D on¶thammer on the outer rim ± it might break ± hammer inside of the ring of the dowel holes

The head of this rubber hammer is filled with leadshot. The inertia of the shotgives solid hits.

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



Notice the dowels are sticking out of what was the top diskshown in the previous picture. If the dowels would be flushwith both disks, the gap between the disks would be2´ wide for a 2´ wide wire coil.

Since I wanted to wind a 1 3/8´ wide coil, I placed 4 woodblocks exactly 1 3/8´ long between the plywood disks andthen I used the rubber hammer to drive the diskstogether. That is why the dowels are sticking out of the diskIn this picture. Remove the blocks and you are ready to winda coil.

A length of ½´ steel rod makes a good axle but awood dowel would be fine. The distance betweenthe dowel rods in the gap between the disks out to theoutside edge of the disks is 1 ½´ so the wire coilwill be 1 ½´ thick. grooves for the cable ties

10´

1 1/2´



This is one cable tie, the lockingsocket on the right end and thetongue end on the left. It loops downbetween the dowels and is held inplace in the grooves. I used 11ćable ties because 8´ ties are notlong enough to pull tight easily.

This the roll of wire thatwill be wound onto the windingspool to make the wire coil.

The coil winding spool. Iused 3´ long screwsthrough the 2x4 bottom of each wire roll stand and intothe end of the 2x4 uprightpieces. This is simply aU-shaped structure.

10´

2 ½´

Clamp to holdwire roll holder

7 ¼ ³



A small hole is dril led here to secure theend of the wire to start the coil. Without thishole the stiff 12 gauge wire could not be pulled tightenough to start the first layer of wire

Cable ties in grooves The first wrap - the start of a good coil is based on havingtight layers and rows.

Once you start to wind a coil you can¶t stopunless you keep a piece of duct tape handyand can tape down the wire on your coil ± itwill unwind for several layers if you releasethe tension



The wire is wound inch by inch with constant tensionwith the fingers to keep the wraps tight. There is nothingfast about this part. Try not to impart bends in the wire bythe finger or fingers that ³lay´ the wire in place. I used my right

index finger to lay the wire in place while turning the spoolwith 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 tightagainst the plywood. I used a screwdriver with a flat bladedend to pry gently ± great care must be taken to not cut theinsulation of the wire. I used a small wood block to push the wiredown 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 thewood 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 cableis tight. D on¶t over do it with the tightening as the tie can cut theinsulation. 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 thedowels one by one through the top plywood disk. Sandor file this dowel (at least the first 1 ½´ or so) so itdoesn¶t stick in the hole



Hang the edge of the spool over the edge of a work table or other solidsurface and hammer the dowels throughthe top disk Once about 10 of the dowelsare sticking out on the other side of thespool ± you can then just balance theentire spool on those dowels to hammer the rest of the dowels out without hangingthe spool over the edge of the workbench.

All of the dowels are now through thetop plywood disk.



The work is almost finished. Ittook 45 minutes to wrap thiscoil. After making 50 coils I canwrap the wire for a coil in 11minutes.

Pry the coil off of the dowels with your fingers. If youcan¶t budge the wire coil you will need to hammer somedowels (hammer them to the left in this picture) so theyclear 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) andwill be used for f requencies over 2000 Hz.



Adding wire to a coilAdding 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 theinductance 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 abouthaving 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 athicker coil and therefore a higher inductance coil.





Its difficult to see in this picture but the end of the wire has been cutat 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 stripbelow 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 designedfor 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 downby its wood strip holder. Use needle nosed pliers to formthe joint so it is as smooth a transition as possible.

Be sure to slip a piece of heat shrink tubing onto one of thewires before placing them in the jig.



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



Here is the soldered joint. It is very strong and willallow 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 tocarefully heat the tubing with a propane torch, a candle, or a lighter so it shrinks around your solder joint. D on¶t over doit since you certainly don¶t want to melt the wire insulation. If you forget the heat shrink tubing you will have to cut the jointoff and start over.



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

Banana plugs ± 12 gauge speaker wire issoldered into the end of each plug. These areavailable at Radio Shack. There is a small screw-inadapter for smaller wire that I removed anddiscarded.

Since the flanged ends of the banana plugs are delicateyou should not squeeze them with pliers. Here I used pliers andtaped the handles together with just enough pressure to hold theplug so it can be soldered.



Heat the end of the banana plug with the solderingiron. Hold the roll in the other hand and insert the endof the solder into the hole carefully so it melts andalmost fills the hole. While the solder is molten insertthe end of one of speaker wires (strip about 3/8óf the insulation) into the hole and hold there untilthe solder hardens (about 10 seconds).

It is easy to forget to put the red or blackplastic pieces onto the wire before soldering.Once the metal plug is soldered to the wire, theplastic insulator cannot be put on the wire. When

the metal plugs cool, turn the plastic insulator onto thethreaded plugs. The other ends of the speaker wiresare connected to the two wires on the coil. It doesn¶tmatter which of the coil wires are attached to thered or black banana plugs, in fact you don¶t need redblack plug covers at all since any color wil l work fine.



Measuring your coil¶s InductanceMeasuring your coil¶s InductanceThere are two ways to measure the inductance of the coilyou wrapped.

The first method is to simply buy a multimeter that canmeasure inductance. Since you will need a meter that alsomeasures alternating current accurately to monitor the

current flowing through the coil when in use, having the samemeter measure inductance is very handy. The meter willhave an H and mH on the dial for Inductance (measured inHenries



If you already have a True RMS multimeter you can measure your coil¶sinductance another way to avoid buying a meter that measures Inductance.Your D CM must be operable to use this method since you need to turn it onto measure your coil¶s Inductance.

Turn on the signal generator and set it for 470 Hz sine wave output. Turn on the 16 f 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 onyour multimeter you can get. Record the frequency you dialed on the signalgenerator when the multimeter reaches the highest voltage

You can calculate the inductance with the formula below. .(the Inductance will be inHenries which means that you will need to move the decimal place 3 places to the right to change the unit to milliHenries ± You cannow use the Excel f req cap switch calculator on the C D by typing in the Inductance to get the switches that need to be turned on for afrequency you choose.)

Inductance = 25330/Freq 2 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 calculationsmanually.

Capacitance = 25330/Freq 2 Inductance

The capacitance will be in microfarads, the frequency should be in Hertz, andthe Inductance should be in Henries. An excellent calculator can also befound at www.opamplabs.com/cfl.htm .

The above calculation can be done with the Excel calculator program called ³freq cap calculator´ given on the C D .



Multimeter Multimeter A well built meter is the Wavetek Meterman 37XR. I purchased one fromElectronix Express at 1-800-972-2225 or athttp://www.elexp.com/tst_38xr.htm. An online search will produce manyother meters for lower prices, I chose to get one that also measuresinductance and because I like to buy tools. Meters are constantly discontinuedand relabeled so don¶t get locked into buying a particular model.

I recommend searching online for best prices and free shipping. Goggleremoved the Froogle option but you can still sort items by price. D o a searchby model number and click the hypertext ³Products´ or ³Shopping´ at the topleft of the page. Click in the menu bar ³by lowest price´ and you will seewhat is available. Sometimes searching like this is not absolute. I havesearched for an item with a opened catalog next to me and searches manytimes don¶t include the company whose catalog I have or their price.



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



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



Range button moves the decimal point

Plug the red test wire into this jack if you want tomeasure the inductanceif your coil ± note the HFor Henries.

This is the dial setting for voltage ± alternating current D ial setting for measuring the inductance

of your coil (microhenries)

The black test wire plugs in here

The red test wire is plugged in here whenmeasuring voltage



Amplifier Amplifier The amplifier in the D CM is used to boost the power input to the coil. The

amplifier of choice among coil machine builders is the QSC RMX1850H D . TheHD represents ³heavy duty.´ The maximum power output is 1800 watts. Themaximum output of contact and other frequency devices is approximately 2 to10 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. Whensearching you will find that many sites do not use the RMX in the name for the

amplifier ± just QSC1850H D . The cost of this amplifier represents about 36% of the total cost to build a D CM



Run 12 gauge wire from here to oneof the terminals of the binding postmounted on the switch panel. The coilplugs into the binding post.

Run 12 gauge wire from here to the firstset of 5 resistors

Run wire from here to the second setof 5 resistors (the side closest to theamplifier). You can screw the plasticinsulator out and fit 2 ± 12 gauge wiresin the hole in the shaft (note that the topblack terminal will have 2 wires connectedto it. The 2 red and other black terminalsonly have one wire connected there.

This is a bank of smallslider switches. Slide allto the OFF position (left)except for the 2 switcheslabeled ³parallel input#4 and #5 to the ONposition (right).

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

.barrier strip (screws)The red wire from the signal generator cable is attached toto the top screw, the black wire from the signal generator cable is attached to the 2 nd screw and a wire loop must be usedto connect the 2 nd and 3 rd screws together. This mean that the2nd screw down has two wires connected to it..



The input from a signal generator to the QSC185H D cannot be greater than1.16 volts RMS (Root Mean Squared) or 3.34 volts peak to peak accordingto the manual. If you use a signal generator other than the Instek SFG2004 model be sure that the lowest output is as low as possible. The Instek2004 lowest output is .1Hz which means that the lowest voltage output isalso very low. A better situation would be to have the lowest output be 0Hzwhich would mean that the lowest voltage output is also zero.

RMS means that the entire sine wave is sampled and can be measured byTrue RMS multimeters. You can usually choose the voltage output of your signal generator - it can vary from some minimum value to as much as10vand 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 signalgenerator.



SwitchesSwitches

You can use regular house wall switches used for lights, etc. - theyrequire more space than toggle switches but they are much less expensive. Ichose to use toggle switches to reduce the size of the switch bank on the frontpanel of my D CM and am very pleased with the result.

Toggle switch

wall switch



The toggle switches I used for this tutorial were purchased from ActionElectronics.

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 #30-310for my first D CM. I recommend the #30-310 or the switch listed below which isthe 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 eachcapacitor array is labeled with letters B thru P, it makes sense to label the switches also.Since my D CM 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 thecapacitance and the letter A thru P. The red and black plugs on the left arethe binding posts where the coil is plugged in for use. A Word documenton the C D called ³cap switch labels´ prints a set of labels for you.

Shown are two banana plugsthat will be soldered onto the endsof the speaker wires connectedto the coil. Each coil has its own15 feet of speaker wire andbanana plugs.

The binding post. The ¼´ plywood switchpanel ends up between the red and blackplates shown on the right. The switches andbinding posts are designed for panels up to¼´ in thickness or thinner.



CapacitorsCapacitors 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 isstored, is measured in farads or in our case with the D CM in microfarads(1/1,000,000 th of 1 farad). The D CM uses 15 capacitor combinations of single capacitors or combinations of capacitors that are connected to 15switches ± altogether 26 capacitors are used. There are really 16 switchesbut one is not connected to any capacitors (switch A). The switches arelabeled with the capacitance value of the capacitors connected to thatswitch and by letters A through P. A Microsoft Word document is providedon this C D that when printed will provide you with labels for your switches (aglue stick is a good way to stick the labels to the panel your switches aremounted on).

Capacitors are used in the D CM to store and release electric charge whichproduces the alternating magnetic field in the coil. The capacitor voltage is180 degrees out of phase with the voltage output of the amplifier and when

these voltages are equal you have achieved resonance in the coil. Thismeans that the two voltages cancel each other out which produces themagnetic field and resistance which results in the heating of the coil.



A resonating coil is necessary in the D CM which is the reason for usingcapacitors. Connecting capacitors together can be done in parallel or seriesconnections. 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. Nowimagine that two trains are next to each other on their separate tracks. Nowif 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 thanadding them in parallel circuits. If you use the capacitors given in thistutorial you will not have to calculate capacitance values since they are

given. If you decide to add additional capacitors to your D

CM such as largecapacitors to generate lower frequencies or very small capacitancecapacitors to generate higher frequencies, you will need to calculatecapacitance values.



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

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

For example: if you have capacitors of 16 f and .062 f connected inparallel , the capacitance of this array is 16.062 f. Your label on theswitch connected to this array of capacitors should be labeled 16.062 f.

If you have capacitors in series ± train cars in a line - the adding of capacitance values is done differently. For example: if you have 3capacitors each of 3 f capacitance in series ± the total capacitance is:

Total Cap. = (1/3 + 1/3 + 1/3) = 3/3 or 1 f The toggle switch connected tothis series of capacitors should be labeled 1 f.



Why do I need to have some capacitors in series and others in parallelmode?

The answer is that you need to have a list of enough capacitances to addtogether and be able to match any capacitance required by any frequencyyou choose. A D CM cannot actually produce all frequencies by turningcapacitors on, just those between approximately 230 Hz +/- and 2000 Hz +/-. The +/- means that your coil¶s inductance will determine how far above2000 and below 230 you will attain.

For example: If you choose to generate a frequency of 625 HZ you wouldneed a capacitance of 7.619 f with an 8.51 mh coil, but what if you onlyhad 5 capacitors connected to 5 switches with capacitance values of 16, 8,4, 2, and .1 f. You would not have the right capacitances to add together to have a total of 7.619 f. So capacitors are connected together so youcan attain enough capacitance values that allow you to match almost any

capacitance needed for the frequencies the D CM can produce. It would bepossible and perhaps useful to expand the list with additional capacitors andswitches to ³fill in the gaps´ of the list but when you actually use your D CMyou¶ll find that the capacitance list is very adequate.



So to answer the question again ± youneed a variety of capacitances so their values cover the range of the ones youneed for your required frequencies. Thelist on the right is very adequate for aD CM.

For example: Examine this list of thecapacitances used in this tutorial for thebuilding of a coil machine. If you choosea frequency that required a capacitanceof 2.662 f you would have to turn on theswitches with capacitances of 2, .5, .122,

.033, and .007 to give a total of 2.662 f.You would flip the toggle switches F,H,J,L, and O to the up or on position..

30 f B 16 f C 8 f D 4 f E 2 f F 1 f G .5 f H .25 f I .122 f J .062 f K .033 f L .015 f M .010 f N .007 f O

.005 f P



Here is a photo of the front of a coil machine. Notice that there are 16toggle switches each labeled with the capacitance of the capacitorsconnected 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 bedone by using the switches. Instead you can use the A switch alone for anyFrequency lower than about 230Hz that requires a capacitance higher than62uf.

This is the binding postwhere you plug in the coil

switches A - H

switches I - P



Switch Labels ± The C D contains a Word document titled ³cap switch ³labels´that will print a set of labels for your 16 switches

A no cap K .062 f B 30 f L .033 f C 16 f M .015 f D 8 f N .01 f

E 4 f O .007 f F 2 f P .005 f G 1 f H .5 f I .25 f J .122 f





Making capacitor arraysMaking capacitor arrays

There are 16 toggle switches on a typical D CM and are each connected tosingle capacitors or capacitors in series or parallel connections. Toggleswitch A is the only switch not connected to any capacitors. When it isturned on all the other capacitors are inactive. In the next slides we willbuild 2 mounting platforms for all of the capacitor circuits. These platforms

are nothing more than two pieces of birch plywood that are held in anupright 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 inshelves. 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. Youcould easily eliminate the cart and build a box or cabinet structure that could

hold the capacitor panels. The most important feature is that the switchesmust be mounted on a ¼´ thick panel so they can be wired to thecapacitors. A panel for the switches could also just be supported by framingwood ± the switch panel must be 1/4´ thick to accommodate the toggleswitches and binding post.



To start building capacitor arrays I cut two panels (15´ x 9´) of birch plywoodleft over from another project. There is nothing special about this panel size

except that everything fits on the 4 available sides and there is adequatespace between all components.

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

The two panels are shown here. The far left panel has the 2 setsof resistors on the hidden side. This is a view from the back of the cartso the switches are all just to the left of the binding post

This wire is going from the

left terminal of the binding postto the negative output terminalon the back of the amplifier whichis on the shelf below.



VellemanS oldering S tation

Model VTSS5U

http://www.elexp.com/sdr_ss5u.htm

This is an example of an inexpensive soldering iron withtemperature control from 374 to 896 F. A handy featureis the black tube for holding the hot iron when you arebusy getting the next connection ready.

This is .062´ rosin core solder and is a good size touse for this project. Shown is a 1 pound spool but muchless is required to do all the soldering for a D CM. I got thisspool at Radio Shack. Make sure that you get non-leadsolder (which is tin and antimony).

Cable ties and cable tie mounting bases (Home D epot and Lowe¶s).You could eliminate these bases by simply drill ing holes in the plywoodpanels 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 asthe ones attached to capacitors and resistors. These are bare and electrifiedwhen the coil machine is in use plus capacitors store electric charge and maybe dangerous to touch well after you turn the components off You may have towrap protective insulating tape around these wires. A cart with exposedelectrified 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 thecapacitors 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 fromAllied Electronics at www.alliedelec.com .The total order quantities and part numbers are given below.1 - #225-5010

3 - #591-70451 - #591-70252 ± #591-42053 - #591-42002 - #591-60852 - #591-60751 - #591-61751 - #591-61651 - #591-61601 - #591-61555 - #591-61503 - #591-6145

The list given on the next page shows the capacitors that will be connected to each toggle switch . I recommendthat 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 thebags for the part number ± then remove that capacitor, search any others that belong in that connection ± connectthe capacitors, mount them to the shelf, panel, or whatever you are using and then go to the next array. Themajority of the switches have only one capacitor in the circuit so the term ³array´ may not strictly apply ascommonly used.



S witch Capacitance Q uant ity/connect ion Allied Elec. P art

A noneno capacitors used for thisswitch

B 30 f 1 / one capacitor used 225-5010

C 16 f 2 / 8 f in parallel 591-7045

D 8 f 1 / one capacitor used 591-7045

E 4 f 1 / one capacitor used 591-7025

F 2 f 2 / 4 f in series 591-4205

G 1 f 3 / 3 f in series 591-4200

H .5 f 2 / 1 f in series 591-6085

I .25 2 / 0.47 in series with 591-6075

1 / 0.015 f in parallel 591-6150

J .122 f 1 / 0.1 f in parallel with 591-6175

1 / 0.022 f 591-6155

K .062 f 1 / 0.047 f in parallel with 591-6165

1 / 0.015 f 591-6150

L .033 f 1 / one capacitor used 591-6160

M .015 f 1 / one capacitor used 591-6150

N .01 f 1 / one capacitor used 591-6145

O .007 f 2 / 0.015 f in series 591-6150

P .005 f 2 / 0.01 f in series 591-6145

These capacitors can be orderedfrom 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 ³cabletie mount bases´ (Home D epot) to secure the capacitors to the panels. For single capacitors I usedthe adhesive back to secure the mount base but where larger capacitors were involved, I used #6 x3/8´ Phillips screws to secure the mounting bases to the panels. An easier way to mount thecapacitors is to drill holes through the panel and use cable ties. If you use a metal mounting panelyou will need to use rubber sheeting to keep the metal capacitors from contacting the metal. GeneD illman found considerable stray current in his metal cabinet but solved the problem by insulating themetal capacitors.

This is the 30 f capacitor. The darkstrip of wood on the left edge of thepanel is a cap of cherry that hidesthe edge of the plywood when thisplywood was used as a shelf long ago.

These are two of the cable tiemounting bases. They have slotsfor the cable ties to pass throughand up around the capacitors. Theties are 7 inch ties and are justlong enough for all the capacitorsused in a D CM.

The mount bases have an adhesivebacking but when mounting thelarger capacitors there is some pryingaction when you tighten the cable tieand the adhesive releases. Thisprying occurs because two bases areused for the large capacitors so theycan cradle in the gap between thetwo mounts.



This 30 f ( P ART 225-5010 ) capacitor is the only oneon switch B. I label all capacitors to avoid mistakes in

wiring to the switches. Avoid pulling too tightly on thecable ties. The capacitors shouldn¶t move around butmake the tie just snug enough.

These capacitors for switch C, each 8 f ( P ART 591-7045 )will be connected together in a parallel circuit so they shouldbe mounted near each other.



On the next page these capacitors will beconnected in a parallel circuit

The 4 f ( P ART 591-7025 ) capacitor for switch E hasbeen mounted to the panel and above the 8 f ( P ART 591-7045 )for switch D will follow.



The short pieces of 12 gauge wire have their endsstripped of insulation and the spade connectors

will be crimped on. These wires are used to connectthe two capacitors in cap array C together in a parallelcircuit.

Use this section of the cr imping tool to secure the connector to the wire ± be sure there is no wire insulation in thealuminum collar that will be crimped. Also be sure that the wiredoes not turn independently of the connector ±if it does crimpIt some more. Notice how flattened the yellow insulation iswhere the crimping pliers were used



The capacitors used in a D CM do not have plus andminus terminals. By connecting the top terminals together and the bottom terminals together you get a parallelcircuit (even if you turned one of the capacitors 180 degrees

and rewired it. Here the panel is lying flat and in the pictureto the right it is upright on its edge ± the way it will bemounted 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 62 f which is the sum of all capacitorsin a D CM.



These 4 f ( P ART 591-4205 ) capacitors for switch F willbe in a series circuit. It doesn¶t matter which ends youtwist 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 youstart the twist be sure to pinch the spot where the wirescross so the twisting doesn¶t migrate down toward thecapacitors.

They don¶t all work out to be this neat but this one makesa good picture.



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

D ecide where you want to place them then attach mountingbases and cable ties or drill holes and use cable ties.



This series connection of 2 - 4 f ( P ART 591-4205 ) capacitor will be connected to switch F For switch G three 3 f ( P ART 591-4200 ) capacitors will be

connected in a series circuit



Twist the wires together as before - place the array to determinethe location of mounting bases.

Using a marker to label helps when wiring the capacitors together.Its just another way to keep yourself organized



Capacitor array H two 1 f ( P ART 591-6085 ) to be connected inseries to switch H is shown mounted on the panel. Notice that thewire twists that will be soldered are all out where a soldering ironcan be used very easily.

The capacitors for switch I involve a parallel and a seriescircuit. First connect two .47 f ( P ART 591-6075 )capacitors end to end. Use needle nose pliers to make abend In each of the free wires so they are perpendicular to the two joined capacitors. Connect a .015 f (P ART 591-6150 ) to these free wires which results in aparallel connection I used pliers to twist these connectionssince the available wire for the parallel connection is limitedin length.

parallel

series



Just a few more arrays on this panel will be enough. Switch J is connected to capacitors in a parallel circuit.Connect a .1 f capacitor ( P ART 591-6175 ) front to frontand back to back to a .022 f capacitor ( P ART 591-6155 ).

They are shown here mounted to the panel.



Switch K is connected to two capacitors connected in aparallel circuit. Connect a .047 f ( P ART 591-6165 )capacitor front to front and back to back with a .015 f (P ART 591-6150 ) capacitor. D on¶t twist the wire somuch that the capacitors get close together.

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

F

G

H

I

J K



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

This is another single capacitor for switch M. It is a .015 f (P ART 591-6150 ) capacitor.





Soldering capacitor arraysSoldering capacitor arraysSoldering is easy and fun. Be very careful with the hot soldering iron tip since it would be very easy to melt a hole inthe casing of a capacitor. Ventilation is a good idea because the flux in the hollow core of the solder wire vaporizeswhen you melt the solder. Vaporized flux damages the eyes and lungs. Once the soldering tip is hot, touch the wiresto be soldered and melt some solder on the tip of the soldering iron. The solder flows by capillary action so to ensurethat 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 wirequickly. Heating too long can ruin components like capacitors.

This is a strip of solder coming directly from a1 lb. spool.

h h hh h h



Connecting the capacitor arrays to the switchesConnecting the capacitor arrays to the switchesEach 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 actuallydo have a series connection and not a parallel connection. I chose to usesolid 12 gauge wire to connect the capacitor arrays to the switches becausethere is always enough left over from coil winding but you could use strandedwire 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 thengoes to the bottom spade terminal of the respective switch. In thecase of the large metal jacketed capacitors with spade terminals,a spade connector is crimped to each end of the wire so no solderingis necessary. The switches shown have 3 male spade connectors.Switches with just 2 are easier to use since you don¶t have to figurewhich one is not used.

Here a spade connector is pushed onto one of the twoterminals of the 30 f capacitor for switch B. Each of the2 terminals has 4 spade connecting spots. You can chooseany of the spade ends but when we connect all the capacitorstogether later you must use the other terminal to connect a wire to.The grey wire shown goes to switch B so the upper terminal with4 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 eachcapacitor array are all connected together and will go to thebinding post where the coil plugs in.



You can choose any of the 4 terminals on these parallel capacitorsto connect to the switch. I chose the one on the lower capacitor andthe terminal back toward the panel. The grey wire is going to switch C.

When we connect all the capacitors together later, the terminal awayfrom the panel (on either capacitor must be used).

The 30 f capacitor is connected to the bottomspade end of switch B.



Connecting capacitor arrays that don¶t have spade terminalsrequires soldering directly to the capacitor wire. An easy wayto do this is to use about 3´ of a strand of stranded wire andwrap 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

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



Capacitor array F is connected to switch F. You can connectall the other capacitor arrays to their respective switches but Irecommend that you first do the operations on the next fewpages. The reason is that finishing the capacitor to switchpart is easy ± just push the spade connectors onto the lowestterminal of each switch. The next steps require a lot of finger room and will prove to be easier if all the switch wires were notin the way.

To avoid photographs that were mostly masses of wiresand clumsy to work around. I do not have the switches andcapacitor arrays connected to their switches in the next severalpages. 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 16wires. Attach the spade connectors to the middle terminal onthe back of each switch. Spread the strands into a fan to makethe next step easier. The top-most terminal on each switchis not used.

There is an alternative method for this wiring shown in the lastsection of this tutorial.



Take the remaining 4´ sections of stranded wire andstrip 5/8´ on insulation off of both ends. Spread the strandsinto fans as shown above.

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



Here two of the pieces of wire and the wire attached to switch Hare twisted together. D on¶t use pliers to twist since many of the finestrands may be broken. It is sufficient to use your fingers. Use analligator clip or two to hold the three wires in place for soldering.

The connection has been soldered. When the solder coolsuse a red wire nut to cap the connection. The stranded wirethat is almost vertical in this picture will be twisted with thewire immediately behind it and another loose piece of wire.What we are doing here is using the loose pieces of wire to

³jump´ from one switch to the next. In the end all switcheswill be connected together.

The piece of wire pointing to the left coming from the solderedconnection will be twisted with the wire below it and a loose pieceof 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 andcapped with wire nuts.

This photo shows the detail of switch H. Notice that the wirenut has two ³jumpers´ which allow you to continue across thetop row of switches to the right to switch A and down to thebottom row of switches to the right to switch I. When you getto 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 wirewill be connected to both set of resistors

Notice the grey wires that are soldered to the bare copper wirethat connects a set of resistors. The grey wires go to the left andare attached to the black wire. The black wire goes behind thewood panel to the wire nut that leads to switch I as shown in thepicture to the left. The above resistor panel is not in the picture tothe left ± it was added to show how the resistors connect to theswitches.

Building the resistors sets is discussed in the resistors section.

switch I



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

The other two grey wires go to the right andgo the back of the amplifier. Notice they aresoldered onto the bare copper wiresconnecting 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 attachedto the other terminal go back toward the left. The wires willbe connected together and with ³jumpers´ will be connected toall 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 atan angle which suggests that the top capacitor is larger. Notice that the wire going to switch Cis connected to a different terminal than the wire going to the left. Both of these wires couldhave 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 ³jumper´ wiregoes 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 s tripped so the bare end can be wrapped with a strandof copper wire and secured to the post for soldering.



Grey wires were soldered to the ends of the capacitor arrays and twisted withelectrician¶s pliers and will be soldered. The wire to the lower left is a ³jumper´ that willconnect with a group of capacitors mounted on the panel to the right. Again noticethat the wire on the other side of the capacitors will be connected to their respectiveswitches but are not yet connected in this picture

This picture shows the 3 rd panel of capacitor arrays ± the other side of this panelis where the resistors are attached.



There are too many capacitor arrays on these two panels to twist all the wires together so I madethree bundles of wires connected by ³jumper´ wires. The arrow points to the ³jumper´ that isalready connected with the wire nut to all the capacitor arrays on the panel to the left. The nextpage shows the 3 bundles.



The

There are 3 jumper´ wires in this picture. The wire bundles with grey wire nuts werecomposed 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 ³New andAlternate Ideas Section.

The unseen side of this panelhas all of the metal jacketedcapacitors on it. The blue wirenut connects all of those capacitorstogether.



This is the wire nut connecting all the metal jacketed capacitors ± the ³jumper´ wireconnects this panel of capacitors to all the other capacitors.

R i tR i t



ResistorsResistorsThere are 10 resistors in a D CM. They are connected in two groupsof five resistors each. The wires coming out of a resistor are not quitelong enough to twist all five resistors together and still havespace for cooling around each one so I mounted each one on a cabletie mounting base.



After 5 resistors are mounted and strapped down, strip alength of solid 12 gauge wire of insulation and wrap about½¶ of each resistor wire around the solid copper wire. D othe same thing on the other side of the resistors. Eachresistor could easily be held in place by drilling holes andusing just cable ties.

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



Here are the 2 sets of resistors. The resistor wire-

copper wire connections should now be soldered.

Choose the side of the resistor sets that is closest to the backof your QSC1850H D amplifier. Two solid copper wires must beconnected to teach resistor set and one must go to the Channel 1Minus output terminal and one must go to the Channel 2 minusoutput terminal on the back of the amplifier. Since my D CM iscompletely contained on a cart, I had to drill a hole in the shelf thatholds 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 solderingsince you will have a roll of solder in one hand and the solderingiron in the other. Use one thin strand of wire to wrap the twotogether and then solder the joint and all the copper wire-resistor joints.



It doesn¶t matter which set of resistors is connected to theamplifier 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 2minus output terminals.

The wiring for the other side of the resistors is discussed in thesection 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 Wave/Signal Generator

Many people wonder how a D CM can pulse a magnetic field at a givenfrequency. It¶s easy ± you choose!

A D CM has as an integral part, a wave generator but you must purchase awave 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 wavegenerators 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 becompatible with a D CM. You must have a wave (sometimes called a signal or audio) generator that emits very low frequency waves - as low as youcan go toward zero waves per second. The Instek SFG-2004 generator produces waves down to .1 Hz (waves per second).



This is the Instek SFG 2004 signal Generator..

This is a BNCjack ± the cablesupplied with thegenerator has a BNCconnector on one endAnd alligator clips on thered and black wiresthat split from the maincable. You canchange the clips tofork connectors thatfit under the screws onthe back of the amplifier if you choose

Coil StandCoil Stand



Coil StandCoil Stand I designed a coil stand that holds the

coil off the back of the stand about ¾

inches for better cooling. There arefour short 1 ¼´ long dowel piecesglued in ½´ deep holes. Each of thesepieces has a ¼´ hole drilled through itso the coil can be strapped down tothese 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 (so3´ of each dowel sticks out of the backof the stand. This dowel length willaccommodate coils that are as wide as2 ½´, which is wider than the vastmajority of coils used in coil machines.The coil shown is an 8.51 mh coil. Thestand is made of red oak. The base is1 1/8´ thick and the tilted back is 7/8´thick. The angle between the backand the base is 14 degrees.

Cutout for handle allows coil to be moved



The cable tie goes through the pillar andaround the coil ± there are 4 pillars holdingthe coil off the back

Cutout for handle allows coil to be movedbut not abraded by constant handling. Cutoutwas made by dril ling overlapping 1´ holeswith a Forstner bit with a drill press.

The coil rests on three 1 inch diameter dowels in addition to being strapped to4 pillar supports with 4 cable ties. The twobottom dowels are really the only ones neededfor support.



Top support pillar

Bottom support pillars



The top right shows that two pieces of red oak have beenglued 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 toactivate 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 thattilts one blade so grooves (dadoes) of various widthscan be ± up to 7/8´. The saw is tilted 14 degreesto give the tilted dado. This helps to move the center of gravity of the 9 lb. coil backwards and stabilizesthe 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 isbeing 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 theleft is the upright

I could do without the sanding part but there areparts for 3 coil stands here and they all need alot of sanding.



The 4 one inch circles will be drilled 1/2´ deepwith a 1´ diameter Forstner bit. One inch diameter and 1´ long dowel pillars will be glued in theseholes for the wire coil to sit on.

The 4 dowel pillars have a 1/4´ hole drilled so a cable tiecan be put through the hole and around the wire coil. Thisstraps 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 andaround the wire coil without twisting.



The other 3 one inch holes are for longer dowels to supportThe weight of the wire coil. The coil for this stand is1 ¾´ thick and the holes are 3/8´ deep so the dowelsupports end up about 2 3/8´ long (they are slightly longer than the coil is thick).

All dowels are glued in place.



Three glued stands. They will dry overnight.The cured glue usually squeezes out and must scrapedoff with a sharp wood chisel. I use one coat of a tungOil..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 upper-most dowel. Coils of different sizes could then just sit on thetwo lower large dowels.



After removing any glue (with a narrow, sharp chisel) thatsqueezes out around the dowels, the stand is sanded andcoated with tung oi lfinish. I let it dry for a day and then

mount the coil with cable ties that pass through the shortdowels and around the coil.

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





This is a finished coil stand with an 8.51 mh inductance coil. The coil¶s dimensionsare 2´ wide and 1 ½ inches thick. This section on building a coil stand is not intendedto 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 lapwhile sitting.

Connecting the speaker wire to the banana plugsConnecting the speaker wire to the banana plugs



Unscrew the plastic insulator from the plug. Asmall adapter (not shown) was screwed intothis plug in case the user wanted to solder very thin wire Into the plug ± just discard thispart. These plugs were purchased fromhttp://www.elexp.com but many suppliers haveThem.

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



Hold the flat bladed tip of the soldering iron against thethreaded end of the banana plug. It will be hot enoughto melt solder in about 30 seconds. Put the end of thesolder into the hollow end of the plug and almost f ill itwith molten solder. Put the soldering iron down andquickly pick up the end of the speaker wire and insertthe well twisted stranded wire end into the molten solder.

Hold it there for a few seconds until it is secure. If you fillthe end of the plug with too much molten solder, it wi ll runout and into the threads of the plug. You might have to filethe threads off if the solder is too thick. Taper the end of theplug with a fine file so the plastic insulator can be twisted onwithout stripping the threads inside. It¶s a lot easier to notfill the hole with too much solder.

The color of the insulated plastic barrel hasnothing to do with the color of the wire in theabove picture. The other end of the speaker wires will be connected to the two wires onthe coil ± do it wrong and there will be a hugeexplosion ± just kidding ± just connect them.

D oug Coil Machine on a CartD oug Coil Machine on a Cart



ggI designed a cart for my D CM so all components could be in one place and alsobe portable. Since the QSC1850H D amplifier is the largest part and heaviest(50 lbs.), the cart¶s dimensions are based on it alone. The lowest shelf holdsthe amplifier, the second shelf contains all of the capacitors, resistors, andwiring to the switches. The top shelf holds the coil stand, the multimeter, thesignal 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. Thelegs and shelf supports (stretchers because they hold the legs in place)are all made of red oak. The shelves are ¾´ oak-veneered plywood. Thewheels are 2 ½´ diameter rubber swivel wheels (Home D epot). I am presentlydesigning a model that will eliminate the cart. The electronics will be in a frameand panel red oak cabinet that will fit exactly on top of the amplifier and willitself be about 7 or so inches high.

Th b dl f i

The 16 switches are here The binding post is here



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

The two sets of resistors are here

The bundle of wiresgoes through a hole inthe top shelf to thesignal generator and themultimeter

The 2 white wires goto a signal generator + and ± output terminals,they come through thehole leading down to theamplifier

One of the black wires isthe power cord for thesignal generator on thetop shelf.

The other black wire andthe red wire are the testleads from the multi-meter located on the topshelf. The red and blackalligator clips are shownattached to a set of resistors.

The side panels have cutouthand-holds. I

The cart seemed like a greatidea because it is mobile butit turned out to be in the waymost of the time. The lastsection of this tutorial has somedetails of an oak cabinet that hasthe same footprint as the

amplifier.



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









New and Alternate Ideas SectionNew 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 (andmany others) sells terminal blocks. You will need 3 if you have 2 uprightpanels 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 aterminal 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 verywell. Strip about 2´ of the insulation from some 12 gauge wire. Use thepliers to grip the wire about 1/8´ from its end. Turn the pliers to bend thewire into a small loop. When you have a 180 degree bend use the pliers tosqueeze 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 terminalblock has 8 sets of screws you will need 7 U-shaped bends of wire. Thepictures on the next page illustrate this idea.



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

Here a loop of wire was formed withthe stripping pliers and then the loopof 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 eachside 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 toconnect 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 nutswould instead go to the terminal blocks. Only 2 jumper wires would still be required to get from panelto panel. If all capacitors and resistors were mounted on one flat surface ± only 1 terminal block would beneeded. The 8 screws could each accommodate 2 wires from capacitor arrays plus the ends of the blockcontaining the copper loops has 2 spots for 2 additional wires. There are actually 18 places wires canattach.

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 areexposed) 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 thisstructure should be same size (or less) as the length and width of the QSC

1850H D 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 baseto allow for air circulation above the amplifier.

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

switches andbinding postgo here

capacitors andresistors

A few screws will holdthe panel to the base.

This base sits onthe amplifier



3. Another idea is to eliminate the extra wiring with jumpers and wirenuts to connect the switches together. A simple solution would beto use #30-305 switches (the switches used in the tutorial #30-310could be used as well) which have 2 terminals and on/off switchaction. On pages 82-85 a wiring method is shown to connect all theswitches to each other with the red stranded wire. All of this could beeliminated by mounting one terminal block on the back of the switchpanel (and use copper U-shaped jumpers to connect all the screws onthe 2 row, 16 screw terminal block together) . Use a length of solid 12gauge wire with a spade connector on its end to connect to the bottomterminal of the switch. The other end of this wire would be connectedunder one side of a screw of the terminal block. D o this operation withevery switch so that 16 switch wires would go to the terminal block. Twoadditional wires would have to come out of the terminal block and go tothe two resistor sets to connect them into the system.

A much more compact D CM 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 aspossible. The main disadvantage is that the space inside the cabinet for

capacitors and wiring is much more limited so the capacitor and resistor layoutis more important since space cannot be wasted. I decided to place theresistors 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 document³Coil Machine Parts List´ on the C D 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 wireto a switch¶s middle spade terminal and attach the other end of the wire to the terminalblock. To do this with all switches would connect all of them electrically. Switch #30-305 only has2 terminals so you would connect the wire from the correct capacitor array to the bottom spadeterminal. The wire going to the terminal block would attach to the switch¶s other terminal. Aterminal 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 blockbut about 1/2´ longer onto the panel. You will need to clamp the wood strip and let the glue dryovernight. Place the terminal block on the wood strip ± mark where the holes are located and drillsmall 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 emailthe ideas to me. Especially important would be structures to house theelectronics portion of the D oug Coil Machine, coil stands, wiring improvementsand I will incorporate them into this tutorial either in the main bodyor in this section. The idea is to make the construction of this coil machine asclear and as uncomplicated as possible for anyone to build. Your name will beattached to your ideas.

Encouragement PageEncouragement 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 understandinitial points. D on¶t give up and say I can¶t do it because you can start andfinish a D oug Coil Machine. Just think for a second that this might be the bestaccomplishment, as far as making something is concerned, in your entire life. Icannot believe that anyone who built a D oug Coil Machine would feel bad

about it afterward ± you will not only feel good, but the most important point isthat 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]

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Build your own Doug coil machine