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Re: KV's and multimeters
From: D.C. Cox[SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent: Saturday, November 22, 1997 2:09 PM
To: Tesla List
Subject: Re: KV's and multimeters
To: Matt
The kickbacks are killing the 555. You need some blocking diodes to stop
the feedback, or, even better, don't use the 555 --- just use the 2N3055
xsistor -- they should run for months with a little resistance in the
circuit to eliminate the spikes. I use a pulse width modulator to drive a
100 amp peak xsistor (Motorola) which seems to hold up well in flyback
circuits.
DR.RESONANCE-at-next-wave-dot-net
----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-poodle.pupman-dot-com>
> Subject: Re: KV's and multimeters
> Date: Friday, November 21, 1997 9:34 PM
>
>
> From: MATTHEW A PRICE[SMTP:ch038map-at-mode.lanl.k12.nm.us]
> Sent: Friday, November 21, 1997 1:45 PM
> To: Tesla List
> Subject: RE: KV's and multimeters
>
>
> >
> > >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!
> ........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
>
> Help!!!! The driver that I was talking about is now giving me seriuos
> problems. I replaced the TV transistor with a 3055 and the voltage was,
as
> you said, increased, but the thing quit working. After trying a few
things
> I decided to try a new 555, and it worked again, but quit again. I
decided
> not to fry anymore 555 (thats what I was doing, and the things don't grow
> on trees!) so I wanted to ask you guys what I am doing wrong. Part of the
> problem may be that I need a higher voltage rated wire, but I don't know.
> The second time it only ran for a few seconds, and I didn't touch
> anything... Please tell me what I am doing wrong
>
> Thanks
> Matthew
>
>