gauge of wire to use

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xtremediver:
ok, first of all thanks for your help. This is what I've done. I re-wired the lamps using 14 gauge wire. I had a 12v ac-adapter but I decided to get a different one. I have one that is hooked up to it now that can either be set to 18 or 24. Both shine up just the way I want it to look. Question? which setting should I use to ensure it doesn't burn out in a couple of hours like the 12v did? Also keep in mind the 12v was hooked up with 22 gauge wire and not 14. And all 15 lamps are dasiy chained together.

Thanks

grafixmonkey:
You're fine daisy-chaining all your lights with 14 gauge wire for sure.

You still didn't say what wattage your power supply is or really what kind of bulbs you have, although I assumed they're 12v bulbs from your other post.

Did you mean to say it switches between 18 and 24? so you're powering 12 volt lights on 18 volts? (not a good idea - just checking?)

If you have to choose between either 18 or 24 volts on 12v bulbs, use 24v and put loops of two bulbs in series, in parallel... like this:

xtremediver:
sorry, the light bulb is 16v and am using the adapter not the cpu power supply. the adapter is set to 18. I thought since I was lighting 15 lamps that alittle more power wouldn't hurt. I figure it would just burn the bulb out alittle prematurely. I can always take that 18 back out and put the 12 in that I have. If you think that would be better and safer.

thanks again.

grafixmonkey:
I'm reading a little misconception about voltage here... the voltage is not something the thing can supply, it's something that it WILL supply. Whether the device takes it or not. Picture having 30 people all running off a 5 foot ledge, and jumping down to the ground below. I'd say those people are rated for about 7 feet - jump them off 7 feet and they're fine. You raise that to 9 feet though, and you're running them above their rated "voltage." Chances are they'll survive but will be gradually getting minor injuries. Put them on a 12 foot ledge and chances are your little "people device" will be broken pretty quick. But they'll still be jumping off a 12 foot ledge. They won't be jumping, but landing 5 feet off the ground, with "power left over." The wattage of your power supply is what's important. It's how many people it can shove off the ledge in a second. Problem is, the people are shoving themselves off the ledge. They determine how many jump per second. The power supply has to keep up, or it will burn out.

Running a 16v lamp on 18v isn't much of a problem. Those power supplies often only get within half a volt of their target anyway. The lamp will burn a little bit brighter, maybe a little bit hotter, will burn out sooner, and will draw more power. Per lamp. Since your lamps are 16v and mine are 12v, I can't make a guess how much power they draw so if you wanna know if things will burn out before you plug it in, you'll have to measure yourself.

If anyone you know has a voltmeter or multimeter, try to measure the current (not voltage!) going through one. Say you get something like 180 mA. That's 0.18 amps.

So, take your measurement... (let's pretend it's 0.18) and do this calculation:

current * voltage * number of lamps = 0.18 * 18 * 15

In this case you get 48.6. So your power supply better be able to supply at least 50 watts, or guess what it's gonna burn out too. Unfortunately those power supplies RadioShack sells are usually 20 or 30 watts so you'd better check on this if you don't want anything to start smoking. And it might not start smoking right away. It might start smoking some day when you've left it on all night, or off at work, and aren't watching it. If your unit can supply 60 watts, it's just about sure to be ok.

At this point I'm gonna suggest you try and find an old AT style (not ATX) power supply from a computer shop around town. Chances are someone will have one somewhere, and it should be very cheap. Those things are almost never rated for less than 200 watts, often 300 or above. You can use the power connectors to power your lights if you use 12v lights. There's a 16 volt connector in there too if you know where to look but it might not be able to supply 50 watts.

xtremediver:
ok, I'll probably buy a second power supply. Just out of curiosity though. My current power supply is 200w. All it is powering is the motherboard, C:\ and D:\ drives. I have one extra A:\ drive power plug and 3 regular power plugs. Although one of those is split off of another. So it would really be only 2 power plugs. The computer itself is P3 933. I haven't yet bought a multimeter to test the current. But was wonderng if I split the lights in half. 8 on one power supply and 7 on the other. Would my cpu power supply be ok? Or would I just be better off getting the 2nd power supply?

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