Tim Hughes wrote:
>Moose wrote: >>nobody else posting on this
>topic seems to have read<<. (Mark's post saying the OM3 is all mechanical
>switches)
>
> As the original poster of this erroneous notion, I did post and agree
> with Mark immediately after he posted the correction to my OM3
> misconceptions. I guess it got more confused after somebody "confirmed" it
> had a thyristor.
>
Oops, guess I deleted it, thinking the matter cleared up, and didn't
remember when others later ignored it to to continue with the SCR, etc.
thread.
>The only good reason for a thyristor would be if the OM3 offered OTF flash
>mode.
>
>Moose also wrote:
>"Another form of thyristor, a triac,..... One of its most
>important uses is in automatic electronic flashes."
>
>I don't think there is a good reason to use a triac for flashes since the
>current flow is kept pretty much unidirectional to protect the flashtube from
>reverse current damage and the triac has a higher voltage drop in general,so
>it would just increase losses. I certainly have never seen one in a flash.
>
You are so right! I meant to add that sentence to the end of the
previous paragraph about the SCR. Thanks for the correction.
> In modern flashes, particularly small flashes inside the cameras, SCR's are
> typically replaced by IGBJT's (insulated gate bipolar transistors)
>
Ah, all after my time with electronics. And here I though I was on solid
old fashioned ground! :-)
> >>But I don't like muddled info.<<
>Agreed, given no OTF flash in the OM3 and works without batteries, the chances
>of there being a thyristor in there are just about 0.
>
Moose
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