Since the voltage is pretty high, the induction pickup can be as simple as some magnet wire coiled around the HT lead. If you just wanted to light up some LEDS, you could drive some opto-isolators and tie their outputs to LEDs. You may even get by with driving a transistor directly as long as you clamp the base with a zener.
If you wanted to get real fancy, you could run the 4 pickups into a micro and slow down the LED transitions until you got something that looked cool. You could also have it latch a misfire warning LED when one cylinder misses. Wire up a LCD and you could even display RPM... a shift-now light... bar graph RPM indication... even a flux capacitor control for time travel! Oops... got carried away... Gene '79 Spitfire 1500 '88 Jeep Cherokee TSV http://webpages.charter.net/eighmy/spitfire > Here's one for you electronics people... > > > Anyone know how to make an induction pickup? > > Might sound odd - but I have this feeling in the back of my head that > my engine misfires every so often... > > I thought it would be most useful to build a device with 4 LEDs on - > each one hooked to an induction pickup on each HT lead... > > I'd get a cool Night Rider style effect at idle too... *** http://www.team.net/the-local *** Your messages not reaching the list? Check out http://www.team.net/posting.html *** unsubscribe/change address requests to [EMAIL PROTECTED] or try *** http://www.team.net/cgi-bin/majorcool *** http://www.team.net/mailman/listinfo *** Archives at http://www.team.net/archive *** Edit your replies!