Staccato Problem Solved - I Think

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Chris Fanjoy" <zappyman@xxxxxxxxxxx>

  I was getting tired of trying to correct the problem I mentioned 
in a previous post. I couldn't seem to keep RF noise from reaching 
the gate of the SCR, causing the coil to operate in CW rather than 
pulsed. Then I got the bright idea to use a relay. Instead of using 
the staccato pulse to drive an SCR, I used it to feed the base of a 
transistor, which then applies the required voltage to a small relay. 
It seems to work great in initial testing; the coil can now run at 
full voltage without any apparent problems. But it will be some time 
before I see how the relay holds up - some sparking occurs on the 
contacts, so I'm guessing they won't last forever. The other downside 
is that the pulse width must be quite wide to trigger the relay. And 
of course the relay makes a bit of noise, but it's still nothing 
compared to a conventional spark gap!
  Anyway, I think this project is finally back on track. I'm 
surprised nobody has suggested the use of a relay before....