3 Jan
2006
3 Jan
'06
7:01 p.m.
Incidentally, I made a relay flup-flop without
realising it a few months
back. I had a pair of contactors (high-power relays, basically) that
were mechnaically interlocked so they couldn't both close together
and electrically [mutually inverting-coupled].
I fairly quickly relaised it was logically equivalent
to a pair of
cross-coupled NOR gates -- the classic Eccles-Jordan circuit.
Actually, cross-coupled NAND gates - unless you count "power present"
as a logic 0, rather than 1 - because the "maintain memory" state is
power present on both supply lines and the "lost memory" state is power
absent on both, rather than the other way around.
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