1: So I have been playing with transistors, awesome little woks of science aren't they!? Well everything I have done has been arduino based with the same voltage switching as the transistor's input. Now of course there has to be a way to send more voltage across than is used to do the switching, but how do you add a ground and prevent that high voltage from entering the controlling circuit. The basic idea is using an arduino to operate a transistor which controls a 12v DC light source. Lets assume the arduino can't handle 12 volts and can only get up to 5v which is the highest supplied voltage. Can a simple resistor attached to the emitter side work? I still feel like the voltage potential on the emitter would be too high for this to work, but I am new to transistors, any wiring diagram recommendations. I have been through amplifier diagrams, but its too confusing to pick out just what is going on with the transistor, and the most important factor of why. 2: I was looking at aircraft lamps today for the sake of improved vehicle lighting, its quite popular around here, but the majority are 24 volts, at least they are on the brighter end of the spectrum. Now I know you could use two 12 volt batteries and get the 24 volts and also just pull isolated power from one, (i think) to run the 12v system. The problem I see is when applying voltage from a 24 volt alternator, It could potentially bring the 12v system voltage above desired levels right? There isn't a high power easy 12v limiter is there either. So would these require two completely separate systems along with 3 batteries or are there other ways of handling this task which allude me. Bonus: for all those light lovers check out these incandescent beasts!: http://www.normanlamps.com/index.php/cPath/473_53 Oh no, now I realized these are PS type, there goes those radical fun ideas. Would this mean probe start or pulse start, and if so how do they work?