[Sussex] Outcome Re: OT: another hardware question

[Antony]

Desmond Armstrong wrote:
> Antony wrote:
> > I hoped that DC mode would make it easier to provide a ramping (fixed at
> > 2 seconds) gate voltage, leading to a simple DIY circuit adequate for
> > amateur use.  If the current never drops sufficiently for a triac or SCR
> > to turn off, how about controlling AC using two SCRs back to back with
> > RC circuits on their gates?
> 
> No, you can't do that either, as the thyristor is simply 1/4 of a triac 
> (or 1/3 of a modern triac).

Not 1/2?  I guess this wouldn't do the trick then?
AC live - diode - R - (to diac) - R - {R || C} - AC neutral

> I can see that I will have to talk to you on the elements of phase 
> control of these devices. And a bit about controlling AC as well.

Thanks I'm looking forward to that, be gentle!  ;-)

Anthony
PS perhaps we should take this off list now..?