RE: Ford Coil Triggered Gap Testing

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

Hi Terry:

What is the consequence of adjusting the dimmer control with this circuit?
Does the amplitude of the HV pulse change, or does just the phase/timing of
the HV pulses change, or do both timing AND amplitude change?  And for
timing, what is the range of adjustment relative to mains zero-crossing?

Thanks, Gary Lau
MA, USA

>Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net>
>
>Hi Marc,
>
>I fiddled with it a bit and now the AC line input looks like:
>
>http://hot-streamer-dot-com/temp/CoilTest/NewACinput.gif
>
>And the coil input looks like:
>
>http://hot-streamer-dot-com/temp/CoilTest/NewCoilinput.gif
>
>Some of the voltage spikes are radiated noise getting on the big probe and
>are not real.  There is a 240 volt MOV across it and if I disconnect and
>short the probe, the noise is still there ;-)  The Tek5100 probe would be
>far better but the big probe can take a direct 40kV hit.
>
>So it is well under control and very tame now.  I'll have to look at the
>grounding system some more and see if I can get rid of that $30 line
>filter.  It would be nice to model the thing and do some fault studies
>(like discharging the primary cap into the coil's output and the coil's
>input wires) to be sure there are no holes that could blow it up.  Far from
>done yet but the problems should be tiny now...  Probably should ground the
>coil can too...
>
>Cheers,
>
>	Terry