Re: ignition coil
From: William Noble[SMTP:William_B_Noble-at-msn-dot-com]
Sent: Wednesday, July 23, 1997 4:42 PM
To: Tesla List
Subject: RE: ignition coil
SCR is a solid state device that is best thought of as a diode that can be
switched on by a pulse to the gate, and will stay on until the current through
the diode drops to zero. Place SCR, capacitor, ignition coil primary in
series. Add a charging circuit to put 200 to 400 VDC into the capacitor.
Make polarity such that current will flow when diode conducts. Suggest 1
microfarad as a good start for capacitor value, but as low as .25 will be ok.
Set up 555 to produce short (a few tens of microseconds to 100 microsec)
pulses that are positive going. connect 555 to SCR so pulses drive gate
positive with respect to the cathode. I could scan a schematic, but it may be
easier for you to look at an SCR handbook to get the idea.
From: Tesla List
Sent: Wednesday, July 23, 1997 8:19 PM
To: 'Tesla List'
Subject: Re: ignition coil
well, I'm new to this stuff (basicaly) and I don't know what a SCR is,
what it does, etc.
regardinf the 555 oscilator, I bought a circuit that was a 555
timer/oscialtor, either/or. I assume
that will work?