I’m trying to make a very compact circuit that will detect a laser beam’s presence and then allow 3.7V from a lipo battery to flow continuously through 3 LEDs in parallel, regardless of whether or not the laser is still present. Basically, I need a switch that is activated by intense light. Can anyone suggest a component or simple combination of components that will help me achieve this effect?
And, while I’m here asking questions, how could I set this up to have the LEDs fade on, instead of just turning on? I’m assuming using a capacitor-resistor circuit inline, but if anyone knows how to do this off-hand, I would really appreciate if you could post a schematic for me. This is an added bonus for my project, but would be really awesome if I can fit it in.