So a car runs off of 12V DC right? Well, that's what they're supposed to. I decided that I would add some chrome LED windsheild washer nozzles to my case to be original, and because they also ran off of 12V DC. No one told me that they needed to be hooked up to a relay (which I still don't know what it is). So once I soldered them to a spare molex I had lying around, and drilled the holes, and stuck them in and everything, they looked pretty cool. So I turned on my computer. They started out nice and bright, but then started fading, until finally one started smoking and the other one caught fire. I don't have any pics, as I'm going to show them with the rest of the finished mod (later on). So now I'm off to find some new LEDs, and some resistors, to make sure this doesn't happen again. Hopefully someone could tell me what happened, or at least learn from my mistake.
I thought a relay was something which used a small current which is safe to switch to open up a circuit providing a large current. For example, on a car ignition. Someone correct me please if I'm wrong. Btw, I think the problem must have been because of the amperage from the power supply rather than the voltage.
Adams description of a relay is correct. Its kind of like a transistor, but the mechanism is mechanical. The small base voltage going to the relay will trigger an electromagnetic switch thingy allowing a lot more current to flow between the main terminals of the relay. however, i dont think the statement about 'amperage from the power supply' is correct because as long as a circuit is designed to take 12v dc, and you give it 12v, its not going to fry just because your groovy pc power supply CAN supply assloads of amps. The circuit will draw the current it needs. the thing is, i know jack about cars, so i dunno why things burnt out for you. perhaps there were a few resistors in series with the car's light circuit somewhere that you forgot to duplicate in your circuit. perhaps the relay is used to rapidly switch the lights on/off really fast so it appears to be on, but is actually on for only half the time so it doesnt heat up as much. anyways those are my dumb ideas im bored
A car battery can give up to around 2k amps in a dead short A PSU can be worked out using Volts/Watts = Amps Jam a steel rod between the poles of a car battery and watch how quick you get dead for further proof) rgrds Dalt
I shorted one with a screwdriver once lol... It kinda glowed red hot while I was holding it. Damn that hurt. Threw the battery out in the yard cos I was afraid of it blowing up, and the casing split too, and I ended up with f*cking hydrochloric acid all over the yard and a melted screwdriver and a bloody great burn on my left hand!!!!! Ahhhh!!!! Well it wasn't my battery anyway These things are dangerous anyway...
