Peter L. Peres wrote:
>
> > how do you switch that SCR off?  Turns out, you switch
> > a capacitor across the device which diverts the current
> > around it for just a few micro(?)seconds and that's
> > enough to turn it off.  Pretty impressive, I thought.
>
> Barry, the two-thyristor scheme was used extensively for horizontal
> deflection and HV circuits before HV transistors were available. Try to
> get hold of a Grundig color TV set schematic from about 10-15 years ago.
> Maybe Roman has one. It's a neat scheme. Of course the theory is discussed
> in contemporary application notes (from ITT and others).


We didn't get many German sets here, but I have seen
that system. Some even used the deliberate ringing
of the driven transformer to turn off the SCR. I do
know I have a heap of those old Thyristors lying
around, high voltage medium current TO-3 etc.
Good paperweights. :o)
-Roman

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