On Thu, 13 Jun 2002 20:40:44 +0100, "Andrew Tierney"
<urbex@xxxxxxxxxxxx> wrote:
>Hi,
>
>I have been looking at the circuit diagram for the T32 and the OM 2 (not 2N).
>The TTL socket is derived straight from the contacts on the hot shoe, so I can
>check these.
>
>I also looked to she how the pulse of voltage on the flash quench works. On the
>OM 2, it is simply connected to the shutter magnet coil via a resistor. The
>back
>emf when the coil turns off sends a voltage pulse. So, if the shutter is
>working
>(as in changing in speeds), then unless this resistor is broken, or a loose
>contact somewhere, then the pulse must get there.
>
That surprises me. First the shutter has to stay open for 1/60
second, yet the flash must receive its quench pulse in something less
than 1/1000 second (assuming full power is 1/1000 second). Doesn't
seem to add up!
>This of course assumes that the 2 is the same as the 2N in this respect.
I don't think it is. There is definately an IC (IC501) from which the
flash quench is sent.
I would be very interested to hear more about this, too!
Regards
John Gruffydd (Mold, Wales, UK)
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