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Re: Using sync gaps



In a message dated 98-09-28 00:14:25 EDT, you write:

<< Hi John,
 >	In my case, nothing else but the gap needed to change.  My single 60mA
> neon is a non-resonant charged system (the neon's voltage and current are
> 15kV at 60mA with 120 VAC in charging 20nF of capacitance).  It was always
> designed to run at 120 BPS  My attempts to run with lower value caps and
> higher BPS never worked as good as the 120 BPS non-resonant mode (I
> probably didn't turn it up high enough :-)). 

Hi Terry,

Yes, your cap is *big enough* to do the job.

> I did put a powerful safety
 >gap on the neon output but this is more to protect against secondary from
> primary strikes which modeling shows is "bad" (I don't use strike rails).

I don't either.

> However, with the protection gap, the neon and all will be kept within
> their ratings in such an event.
> 	You are very correct in pointing out that if you change from a static to a
> sync (or async) gap in a resonant charged system, you must have an
> effective safety gap system to protect the neon from over voltage and over
> current.  If the gap miss-fires, the over voltage will arc at the gap and
> in effect provide a load to drain the energy from the rising voltages of
> the resonating charging system.  If this load were not there, the resonance
> could easily charge the system up to several times the normal voltages and
> blow the neon, caps, etc.

Those safety gaps are great.  I carboned tracked a couple neons
before I started using them.  The async gaps are esp. destructive to
the NST's (they demand, to permit coil operation, a wider safety
gap due to the erratic and skipped firings as you said, but I didn't 
really experiment much with the asyncs + NST combo).  At least
the sync-gaps fire every half cycle unless somethings really wrong.

John Freau
 
 >	Terry Fritz
  >>