Posted by Ryan Osborn on August 17, 1999 at 13:18:29:
In Reply to: Illuminated pushbuttons - electronics question posted by matt(v) on August 16, 1999 at 23:16:53:
: 2) use the current LED as a kind of switch. hook up a 12 volt battery to the bulb in the pushbutton and wire it through the LED, now that I wriet that I can see that would fry the LED straight away. useless
: So has anyone done this? if so how? I guess you could use a transistoror or two but i don't know enough about electronics to make this work. Any ideas are welcome
A transistor would work, or something much easier would be to use a relay. Use the current that lights your keyboard LED as the switching current. The relay can then complete the circuit for the pushbutton light. It might sound like a car's turn signal while flashing though. If that bugs you then it would be time to go with the transistor solution.