I’m using laser pointers to trigger light switches, but I need to power them from power supply, not batteries for easier maintenance for long-term exhibition (2 weeks). I got cheap laser pointers ($1.75 each), and they run with 3 button cells (total of 4.5v).
First thing I did was to directly hook them up with 5v power supply, but it stopped working after 10 second I pressed the buttons.
….well, no surprise!!! Looks like they won’t work with more than 4.5v, otherwise I’m frying them up.