So, here my problem: I'm 16 and have self taught myself a he'll of a lot about electronics and so on, I have been a main attribution to the building of a Cnc wood lathe that has 2 cutting heads which cut simultaneously and I have also wired a switchboard consisting of 2 transformers, 4 contactors, 2 pneumatic solenoids, 2 three phase motors, a VFD, a user interface of 14 buttons/switches, 28 relays, multiple limit switches, and a sophisticated emergency system! So everyone tells me how they would love to employ me! Enough about me and now to my latest little project which is a simple taper charger with current limiting using lm317 regulators the problem is that I don't know much about transistors and apparently I can somehow incorporate an led with a transistor and resistor that will light up once the charge cycle is finished! That is when the input current to the charger drops below about 20mA! Anybody like to help me? Preferably not tell me how to but teach me how to?