This should be dead simple, but I'm obviously not searching for the right things. I basically have a circuit that lights up an LED. I want to replace the LED (or add on to it) with a switch. When power goes through the LED, I want another thing to turn on. I tried using a relay, but the voltage was too low (< 2V). It actually worked the other day, but I guess the battery is getting lower or something and it won't work anymore. I imagine this can be done with transistors or something instead of a relay, since everything is low voltage.
