On Sat, 08 Jan 2005 10:01:54 -0800, DaveC wrote:

On Fri, 7 Jan 2005 16:07:32 -0800, DaveC wrote
(in article et):

Thanks for all the great ideas. All of this makes my (volunteer) job much
easier.

A new twist to the challenge:

The output needs to be a one-shot, momentary-close event. In other words, 5
minutes after power fails, the contacts need to close and open again. This
alerts the alarm to the power out-condition, and clears the alarm sense line
for another event to be reported.

Ideas?

Sure. Use the battery and charger and switch from an emergency light. Use
the 6V or whatever to power a two-555 circuit, or for a more accurate five
minutes, use a 4060. And you could use another output from the
4060 to turn itself off until power comes back on.

Good Luck!
Rich