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Re: SG electric control Idea - opinions wanted



Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, March 31, 2002 7:21 PM
Subject: RE: SG electric control Idea - opinions wanted


> Original poster: "Pete Komen by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<pkomen-at-zianet-dot-com>
>
> Hello Cory,
>
> TRIACs don't  turn off until current through the device goes to almost
zero.
> There are such things as Gate Controlled SCRs, but these are DC devices.
>
> OTOH, trigger the triac just after zero crossing with a somewhat LTR cap
and
> the cap will charge to a peak and current will start to reverse, turning
the
> TRIAC off.  Time the gap trigger to fire after the TRIAC turns off.
>
> Still, High Voltage SS devices are not cheap.  The output voltage of a MOT
> is 2200-2400V.  The peak is around 3300-3400V and I would want to use
> something rated twice that.  Does any TRIAC that can handle those voltages
> exist?  And at a price we can afford?

Triggered spark gaps?

As for SCR's and TRIACs, depending on the circuit configuration, a series
stack of lower voltage units might work just fine.  When the bottom SCR
fires, the voltage across the rest will increase, triggering them.  All SCRs
have a breakdown voltage (forward) and all the gate input does is reduce the
voltage at which it triggers (kind of like reducing the spacing on a spark
gap).



>
> Regards,
>
> Pete Komen
> Original poster: "Cory Roussel by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <imcuddlycory-at-yahoo-dot-com>
>
> Hello again,
>
> i have an idea: it is my understanding SCRs and TRIACs
> arent fast enough switching and dependable enough to
> handle TC spark gap replacement...  it is also my
> understanding that a single MOT is not useful as a TC
> trannie because it doesnt have near enough voltage for
> a reasonable gap, ide like to change this:
> <snip>
>  just an idea,
>
> Cory Roussel
> G1206
>
> __
>
>