Re: SCR spark gap results are in!

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Jim Lux" <jimlux@xxxxxxxxxxxxx>

You're certainly right with that observation.  When all is said and done, a
spark gap is a pretty good switch, especially for relatively low cost.
----- Original Message -----
From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Thursday, December 02, 2004 7:06 AM
Subject: SCR spark gap results are in!


> Original poster: eahab el naga <tesla.dude@xxxxxxxxx>
>
> After much debate and experiments, the results of the SCR spark gap
> are dissapointing. With the large SCRs that i originally planned to
> use, the turn on time was 130us. That was way too slow and the turn
> off time being presumably ten times that. Wile the SCR attempts to
> turn off several cycles have passed making it impossible to turn...in
> turn shorting the powersupply across the primary. Failure....I do not
> stop there...i went and bought hyper-SCRs that have a turn on time of
> 1us and sadly enough the results were the same...with a turn off time
> of 10us the scr would only work with coils less than 60khz. I am
> greatly dissapointed but i am now working on a single transistor spark
> gap replacement. I have a darlington 400A 1000V transistor that is
> pretty slow but i only need 120 pulses per second...perhaps easily
> accomplishable...Like a good friend always told...its hella hard to
> replace them metal switches...
>
> Eahab
>
>