tBot wrote:
> The primary concern
> is of course to stop burning out my ULN2004A's, but limiting release
> latency would be nice as well.

First thing I would do is not try driving 1/3 amp with something that has as
high a turn on voltage as a darlington.  You could be dissipating 350mW in
each.  I don't know how many there are per package, but add them up and they
could well exceed the total device power dissipation.

You could drive a NPN transistor with 10mA base current.  At 350mZ collector
current that requires a minimum gain of 35, which is doable.

As for the snubber, it really should be as close as possible to the relay
coil.  A resistor and diode in series should be fine.  The voltage will be
the diode drop plus the 350mA times the resistance.  With 10V reverse on the
coil, I suspect the current will drop off fast enough that going further
won't make the mechanical relay respond significantly faster.


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