Hey Everyone,
I am fairly new to building raw circuits without the use of a micro controller. I have a small project I am working on for my grandfather. He is hellbent on the idea that if the power goes out at his place his c-pap machine will sufficate him. He knows I tinker so he asked if I could put something together. So I found 2 small cheap devices that I believe should be able to be hacked together to make an alarm loud enough to wake him if the power goes out.
I have a small wall pluggable emergency led flashlight. One of those deals that when the power goes out the light immediately turns on.
Second I have a simple smoke detector. So what I was thinking is this.
I took the smoke detector apart and there are 2 leads that when bridged fire the "test" mode on the alarm. Perfect. Normally with a micro-controller i would just use a transistor or mosfet and wire it up to the leads and done. However, not wanting to put a micro controller on it. I was trying to figure out how I can use the current going to the led in the light to trip the transistor. That way as soon as you flip the switch on the light, or the power comes back on, the alarm turns off.
But I am lost at how to get the led current to trigger the transistor.
Any help would be hugely appreciated both by me and my grandfather. Thanks!
