I have a model rocket launch control system which uses LEDs on each pad to indicate continuity through the engine ignitor. I used 12v LEDs because they draw only 20ma and thus don't cause the ignitor to fire (50ma + needed to ignite them). The problem is that a) the LEDs are hard to see in the bright sunlight and b) I need to display continuity at two points - the launch pads and the main control panel. I figured that using an opto-isolator to power a couple of higher current 12volt indicator lamps would work, but I've not had much luck with figuring out which device to use (or how); most have a current rating for the input (LED) side of the device of 60ma - the one I happened to have in the junk box cheerfully fired the ignitor. Any suggestions for devices (or suggestions for how to find an appropriate device) or circuit ideas? Back when dinosaurs roamed the earth I built some 555 timer circuits, decade counters and the like, but I've never done anything with opto-isolators.
Its a 12 volt DC system with a common ground but separate +Vcc wires for the continuity and launch power for each pad.
Its a 12 volt DC system with a common ground but separate +Vcc wires for the continuity and launch power for each pad.