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| xtremediver:
I recently built a mp3 jukebox I have 14 lighted pushbuttons and 1 coin light. In my arcade cabs I just used a ac-adapter but that won't do for all of these lights. I am going to go into the yellow and black wires on my cpu power supply for the 12v which should be enough power for all the lights. I used 22 gauge for the pushbuttons is this big enough to do all of the lights with or should I go with 18 gauge? |
| grafixmonkey:
I'm assuming you're using incandescent lamps. I tested one of those and they draw around 150 - 160 mA from my PC power supply. 22 is definitely big enough for at least two or three lights at once. If you run a single loop of 22 wire to each light from the power supply, you have nothing to worry about. If you run a single loop of wire and try to put all your lights on it in parallel, you should break it up into different loops with 4 lights each, or use the thicker wire. If you're using LEDs, you can run everything off one loop no prob! All that'll happen if it's too thin is the wire might heat up. You can just feel it after running the lights for a few minutes and check. |
| xtremediver:
All 15 lights stay lit as long at the cpu is on. I'm a bit reluctant to use the cpu power supply though because I did burn out a 12vdc and don't want the same to happen to my cpu power supply. The number on the bulbs are #161. And yes I do have all the lights daisy chained together. I can change this though. I did look into the led lights but not willing to spend $250.00 for 15 of them. So would it be possible to still us a 12vdc and just use 18 or 16 gauge wire instead of the 22. Would it still burn it out? I could get two of them and split the lights in half too if that would help. |
| grafixmonkey:
I can't answer for certain given only the information that's there. To answer fully I need to know what is in the computer, what else is connected to its power supply (besides the computer and the lights), and how much current your bulbs draw. But I can say a few things without all that: The gauge of wire you use will not change the total power your lights consume, neither will how many are on each loop. So, if you have enough lights to burn out a power supply, the wire you use or how you loop them won't change that. However, I misread your first post and thought you had five or six lights... you should definitely not use 22 gauge wire if it's going to carry 2.4 amps, which is what it would with all those lights in parallel. You can use thicker wire, or you can put only three lights on each loop, and have five loops of wire. If you are using incandescent lamps like mine from the illuminated pushbuttons I got from Happ (# C161) they consume 160 mA when plugged into a 12v power supply. 12volts * 0.16amps is 1.92 watts each, and with 15 of them that's about 30 watts. I have an old 300 watt AT power supply I use for testing circuits. On one side of it is a sticker that tells how much power each connector can supply. For mine it's 168 watts for the 12v connector. That's about half of the power my unit can supply. Lacking any real specs to look at right now, I'd venture to assume that holds for other power supplies as well (makes sense - two sources, 5v and 12v, half the power each...). So, take the minimum wattage power supply your particular pc should be able to work in, compare to the power supply you have, and half of the difference is the room you have for powering other stuff off of the 12v connector. I should also mention that you can power your lights off of any power supply you stick in there, so you can easily buy a 30-40 watt 12v power supply from RadioShack (shudder) or maybe some other parts supply store like www.newark.com or www.digikey.com, and those often come in a package that's easy to just bolt or screw to a wood surface, plug in, and connect to your lights. Then you have to find a way to turn the lights on and off with the computer, but there are numerous methods for that. Or you can buy a 450 or 500 watt power supply for your PC, and have plenty of extra power. |
| grafixmonkey:
I should also mention, when the computer is first powered up, there is a strong burst of current being drawn from the power supply, because it is spinning up every drive in the system and recharging all the capacitors that have emptied themselves. This is the most demanding time for the power supply, and the time when having extra power-consumers is most likely to burn it out if you're cutting things close. So, you might consider putting your lights on a switch so you can turn them on after the PC starts up. You could use a momentary contact switch and a single-pole double-throw relay to make a push-on stay-on switch that would automatically turn off when it lost power, so you wouldn't forget to turn it off. Here's how to do it: |
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