Hey. I am trying to build a circuit which would switch on/off another device. So far I have tried using an IR LED on the controller and with a phototransistor on the load device (which has it's own batteries), but I cannot figure out how to get it to work. I do not need complicated signals, just a simple on/off toggle to switch on a 9V motor in series with a 9V battery (like a regular manual switch). Does anyone have any suggestions? Thanks.