Re: Vacuum Gap

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

Original poster: "Daniel Barrett by way of Terry Fritz <teslalist-at-qwest-dot-net>" <dbarrett1-at-austin.rr-dot-com>

 > So I've created my vacuum gap -- PVC electrical 'T'
 > junction and an old vacuum cleaner motor.
...
 > I thought about affixing a phototransistor to the T
 > junction to sense when the big spark happens. That
 > phototransistor would turn the spark into a digital
 > pulse after buffering some of the noise out
 > with a few discreet electronic components.

     I think it's likely that just having the microcontroller within a few
inches of the fact will be trigger enough ;)
Seriously though, the "EMP" (EMI/RFI) near the gap is *huge* and you will
likely burn through "several" microcontrollers and shielding arrangements
until you get something that doesn't crash / reset itself at every firing...
     Maybe a photodiode buried deep inside a shielded box, looking out
through a tube of some sort, as far from the gap as practical, ridiculous
amounts of power supply decoupling, etc-
db