James Newton wrote:
> When the nStrobe line is not connected to the circuit, using a program on
> the PC to toggle the pin, I can get 0.009 - 5.07 VDC on the pin as read by
> my multi-meter.
> 
> When the circuit is connected, and powered up, I get 0.010 - 0.657 VDC and
> the relay does not close.
> 
> I attached a potentiometer between the base an +5 and turned it until the
> relay just activated, then backed it off and tried toggling the nStrobe
> line. At that point I was able to control the relay from the PC port, but
> removing the pot and measuring its value showed that it was 203Ohms. Not K
> Ohms; Ohms. That ain't going to cut it.

Sounds like insufficient base current?  I would try putting an NMOSFET 
in there instead of the NPN.
-- 
Timothy J. Weber
http://timothyweber.org
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