Hello there! I have an idea I want to realise practically, but my electrical knowledge is almost zero. Everything I might have known is long forgotten. I'm asking for a good online course/site or any other resource that would provide me with enough information and examples to cal, wire, construct the following and not kill myself in the proccess: 0) 101 electrical fundamentals 1) A device that would let me turn AC to DC, 2) A device that would let me vary the voltage and amps on a fixed wattage. (Also, ways how to decrease or increase source wattage) 3) A device that would let me switch between a constant current and a pulsating one. 4) Information on electrical discharges, breakthrough voltages, working principles etc.