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Re: Ignition Coils (fwd)

---------- Forwarded message ----------
Date: Wed, 11 Jul 2007 17:13:06 -0500
From: D.C. Cox <resonance@xxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: Ignition Coils (fwd)

Use a MOSFET or small IGBT for the switching to replace the vibratory 
contacts.  Works much better and 35% better performance as no heat or light 
is lost in a spark gap.  International Rectifier has the IGBT drivers for 
$1.42 thru Digi-Key.

We use the Accel Super Coil with this setup to provide a 50 kV trigger for 
our Marx Lightning Impulse Generators.  I use a 2 uF 600 VDC cap with a 120 
VAC voltage doubled line for 336 VDC charging the cap and firing into the 
primary of the Accel Super Coil (JEGS.com for the coils).  Mallory also 
makes a very nice coil, their super duty Drag Racing Coil.

Resonance Research Corp.

----- Original Message ----- 
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Wednesday, July 11, 2007 4:28 PM
Subject: Re: Ignition Coils (fwd)

> ---------- Forwarded message ----------
> Date: Wed, 11 Jul 2007 20:48:09 +0000
> From: Jeff Behary <jeff_behary@xxxxxxxxxxx>
> To: tesla@xxxxxxxxxx
> Subject: Re: Ignition Coils (fwd)
> Hello Scott, Daniel,
> Running an ignition coil from 110V does seem crazy, but I managed to run 
> one
> from 220V, which seems even more crazy:
> http://www.electrotherapymuseum.com/2007/250WT/index.htm
> This ignition coil in the photo is from a Model T.  I'm sure a modern one
> would work even better...maybe someone will try.
> In the old days of points/condensers the voltage on the cap could reach a
> few hundred volts when the circuit was broken.  I just used this concept
> with a spark gap to do in the interrupting instead of the points or
> electronics..and switched the wiring to a normal TC circuit.  The 
> discharge
> is pretty mean, low frequency, not one you would want to come into contact
> with by any means!   I was consuming a little over an amp or from a 220V
> line (actual measured voltage was 241V).  The only tricky bit is the
> tungsten spark gap, which should be near to .001" or around the thickness 
> of
> a piece of paper.  The cap was 1/2 mfd.  I also tried it with a microwave
> oven cap, around 1 mfd.
> I'm curious to test this one day to see how it will power a normal TC
> instead of a transformer.
> Jeff Behary, c/o
> The Turn Of The Century Electrotherapy Museum
> http://www.electrotherapymuseum.com
>>From: Scott Bogard <teslas-intern@xxxxxxxxxxx>
>>To: tesla@xxxxxxxxxx
>>Subject: Re: Ignition Coils (fwd)
>>      I think putting an ignition coil across 120 V AC is asking for a 
>> pile
>>of molten copper (correct me if I'm wrong guys).  They are meant for 12 V
>>so DC input (off a condenser, triggered by the distributer), and get HV
>>by operating at resonance (like a TC, using one off of turns ratio alone
>>doesn't amount to much).  You have to drive the coils with a small solid
>>state circuit (either a 555 timer based circuit, or you can be tricky, and
>>use a circuit like this
>>just wind three windings on a small toroid core transformer (pirated out 
>>something) and they will be your primary, and feedback windings, as well 
>>a winding to put voltage into you ignition coil.  I have never actually
>>tried this, but it does work with flybacks, so it should work with an
>>ignition coil as well.)  After you have your ignition coils resonating at
>>whatever frequency they work best at (my circuit may not perfectly match
>>their frequency, therefore may not be the most efficient, but it is real
>>easy), you rectify their outputs (parallel as many as you want for maximum
>>power, give each coil its own driver though), and make yourself a tiny DC
>>coil.  I wouldn't rule out subbing in flybacks instead of Ignition coils,
>>but you might have to use the old AC type, and rectify them, as I think 
>>polarity of modern rectified flybacks is wrong for your application (maybe
>>it doesn't make a difference!  I don't know).  Good luck.
>>Scott Bogard.
>> >From: "Tesla list" <tesla@xxxxxxxxxx>
>> >To: tesla@xxxxxxxxxx
>> >Subject: Re: Ignition Coils (fwd)
>> >Date: Tue, 10 Jul 2007 20:50:52 -0600 (MDT)
>> >
>> >
>> >---------- Forwarded message ----------
>> >Date: Wed, 11 Jul 2007 02:31:53 +0000
>> >From: Langer Giv'r <transworldsnowboarding19@xxxxxxxxxxx>
>> >To: tesla@xxxxxxxxxx
>> >Subject: Re: Ignition Coils (fwd)
>> >
>> >hey that looks like a pretty good schematic.  Thanks.  Just a quick
>> >question
>> >on it:  The signal generator being the 555 does not show which prongs to
>> >use.  The 2N3055 transistors are pretty staight forward, but I can't
>> >out which of the 8 prongs to use on the 555.
>> >
>> >this is the page that shows the schematic i'm looking at:
>> >http://www.rmcybernetics.com/projects/DIY_Devices/homemade_tesla_coil.htm
>> >
>> >Also, if I wanted to use more power, would I be able to use 120V AC to
>> >power
>> >the coils? (kinda like a small version of a NST)  Would i need heavy
>> >resisting or ballasting?  Could i just use like three in parallel to
>> >increase the voltage I can put accross them?
>> >
>> >
>> >Daniel
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