"George" wrote in message
...
Button Pusher for Time-Lapse Photography

[snip]


Since the relay requires at least 12V, and a fair amount of current,
I used a MAX232 chip to convert the incoming 6V from the battery
pack to a much higher voltage the relay can use, and a large
capacitor to store that charge between presses. The two-transistor
coil driver was suggested by James in the .design group, but the
resistor values are all my fault. Thanks to James and all the
others there who helped me figure this out.

If your relay coil resistance is really 100ohm, I don't see how that MAX232
can supply the needed 120mA. From the datasheet, the MAX232 can only supply
about 10mA (short circuit), but this is with 1uF caps (not the 10uF that you
use).

What voltage are you really getting across the coil when it's on?

Bob