It will need to be battery backed so no AC. It will not likely be working very hard. I almost think if the timer could free run in background and I just looked at it every so often that would likely work. My thinking is the timer is setup to roll over at 1 second and start over and I just watch it from my code. Just keep reading and recording its value and when I notice it rolled back to zero or past I need to do my pulse thing. I just have no idea how to work with the timers.

Matt