RE: KV's and multimeters

To: "'Tesla List'" <tesla-at-poodle.pupman-dot-com>
Subject: RE: KV's and multimeters
From: Tesla List <tesla-at-stic-dot-net>
Date: Fri, 21 Nov 1997 18:30:13 -0600
Approved: tesla-at-stic-dot-net


From: 	Atle Jorstad[SMTP:anjorsta-at-online.no]
Sent: 	Friday, November 21, 1997 10:41 AM
To: 	Tesla List
Subject: 	Re: KV's and multimeters

At 11:16 PM 11/19/97 -0600, you wrote:
>
>From: 	MATTHEW A PRICE[SMTP:ch038map-at-mode.lanl.k12.nm.us]
>Sent: 	Wednesday, November 19, 1997 10:47 AM
>To: 	Tesla List
>Subject: 	KV's and multimeters
>
>	
>Last night I finished the driver for the ignition coil useing a 555 timer.
>I was surprised when I hooked the thing up and it actually worked!
>especially considering I used a HV transistor I found in an ol TV without
>knowning how many amps it could take or anything. The result was amazing
>(hey i'm just your average 16 year old, so even though it wasn't too great
>it was still exciting) The coil that used to put out only about 500 V now
>makes sparks about 1/4 in long. My question is: is there to figure out the
>voltage its putting out? My multimeter is a cheapie that only goes up to
>1000 V. Also why does it spark to everything..even when its not grounded?
>
>Matthew
>
>If you want to make better sparks, put in a variable resistor in the
555 circuit. Tune it until you get the longest spark. The best ignition
coils are the red or blue ones. These are specially for use w/ transistors.
Also, TV transistors arent the best. IGBTs are the best, but simply a 3055
is ok. My ignition coil throws 3/4 inch sparks easily. Or, if you want to
make the longest and fattest sparks, use a thyristor in series with a 1uf
cap and the primary. Feed this arrangement with 250 VDC. The cap charges up
and discharges throught the primary. I used 350 VDC and a 4,7uf cap, that
made 2 1/4 inch sparks!
Atle Jorstad