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Re: TC's power supply

At 11:09 PM 12/31/96 -0700, you wrote:
>Subscriber: dixie-at-icenet.fi Tue Dec 31 22:34:53 1996
>Date: Tue, 31 Dec 1996 15:55:20 +0000
>From: dixie-at-icenet.fi
>To: tesla-at-pupman-dot-com
>Subject: Re:  TC's power supply
>
>> "they are basically a light dimming circuit using a
>> triac and an inductor within a single 3 pin chip. They come in a
>> variety of current ratings, I used 6A which is probably way over the
>> top, but better safe than sorry. You need to get a 1Meg variable
>> resistor to vary the phase angle. So connect up the phase angle
>> device, with 1 meg resistor and place a 3 microdfarad cap in series
>> with the output (use >250 volts rated cap). Now connect to + and -
>> terminals on the coil. You should be able to run the spark gap
>> directly from the HV terminal of the coil. I have got sparks about
>> 30mm (approx 30KV) from this arrangement."
>
>> 	THIS might work OK.  Note the use of the 3 mfd capacitor
>> in the circuit.  This is important, and should be rated at well
>> over 250 volts.  In this application the SCR or Triac is hooking
>> the coil primary directly to the power line through the capacitor,
>> so large peak currents will be drawn from the line (and pass 
>> through the coil primary).  I am using a somewhat similar idea
>> here, based on an original design from Tedd Payne, and it works
>> quite well.  Difference in my case is that I rectify the line
>> to produce about 300 volts DC, then use an inductor to charge
>> the capacitor.  Can get sparks up to 3 INCHES from a single
>> General Motors "High-Energy" ignition coil.  Peak output isd
>> is limited by voltage breakdown around the outside of the coil.
>
>Can you maybe post circuit diagrams here?
>
>> 	I get the coils cheaply from local junk yard (they are
>> in distributor cap of Oldsmobile, Buick, and Cadillac of recent
>> vintage) so haven't worried about destroying them, but so far
>> only real damage has been a short between primary and secondary.
>> 	Give this one a try, don't forget the capacitor, and
>> GOOD LUCK!
>
>What if I forget the capacitor?
>
>
>
>Tero. 


Don't do it. 

I've tryed it.

Without the cap your dimmer will pop first.

If you build a husky dimmer, your coil will explode/burst open/pop the top
spray oil everywhere/catch fire, etc,etc,etc.

Ignition coils are not meant for high power inputs, just high impulse
powers. 30 KV at a few mills is all they are capable of, with normal
circuitry...

It is possible to use a variac to feed low voltage AC to the primary
and get some HV from it, but you'll soon overheat the coil and/or
burn it up.

Testing things to destruction can be fun, but very, very dangerious !

Daryl