Build Your Own Arcade Controls Forum
Main => Main Forum => Topic started by: kagem on June 07, 2006, 11:10:56 am
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Ok, got a jpac and since there's no jamma board hooked up to the power supply, I figured I would use resistors to provide load. I was just wondering if using two 1.0 ohm 10W 10% Wirewound Resistors wired in series would work? I was then planning to use a case fan on the 12v+ rail to help cool down the resistors.
I'm trying to use these resistors since I can easily get them at radio shack. If they have better ones that I can easily get, then please let me know. Thanks.
**Update**
I went ahead and tried it out and it seems to work just fine. I had it on for about 30 minutes and the power supply didn't blow up or turn off so I guess it's ok ;D
Tips if you want to do this:
Make sure you wire the 2 resistors in series and not parallel. Also they do get hot so keep them seperated and away from anything that can get damaged. I attached them on top of an old cpu heatsink with cable ties and wired a 12v case fan pointed at them. I'm not sure if this actually helps or not but I don't see how it can hurt.
The resistors come in a two pack from Radio Shack at $1.79 Catalog #: 271-131
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It would make more sense to just disconnect the AC from powering your power supply.
Or if you want to be neat about it, add in a second AC toggle switch.
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Yeah, I'm still debating which way to go, but main reason I want to keep the powersupply hooked up is because my monitor gets power from it, and this way I can easily pop in a jamma board if I wanted to.
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Yeah, I'm still debating which way to go, but main reason I want to keep the powersupply hooked up is because my monitor gets power from it, and this way I can easily pop in a jamma board if I wanted to.
Wait, are we talking about a power supply or the AC distribution block? I've never heard of a monitor that can run off DC voltage (unless you've got one of those mini LCD screens...?)
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reference:
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What about some light bulbs as a load?
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Yeah, I'm still debating which way to go, but main reason I want to keep the powersupply hooked up is because my monitor gets power from it, and this way I can easily pop in a jamma board if I wanted to.
Wait, are we talking about a power supply or the AC distribution block? I've never heard of a monitor that can run off DC voltage (unless you've got one of those mini LCD screens...?)
Actually, it doesn't get power from the power supply itself, it's just wired through the power supply. I want to keep it that way so I don't have to rewire it and swapping in a jamma board will be easy.
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What about some light bulbs as a load?
I was thinking of doing that also, but I figured a resistor will be smaller and won't heat up the cab as much.
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10 watts isn't enough heat dissipation for that resistor. You'll find it gets real HOT real fast! Here's exactly what you need at Mouser Electronics (www.mouser.com):
# 588-L50J-1.0 Ohmite fixed vitreous enamel power resistor, 1.0 ohm, 50 watt
It's only $7.18 for it and is the proper one to correctly load the 5 volt line on the power supply.
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10 watts isn't enough heat dissipation for that resistor. You'll find it gets real HOT real fast! Here's exactly what you need at Mouser Electronics (www.mouser.com):
# 588-L50J-1.0 Ohmite fixed vitreous enamel power resistor, 1.0 ohm, 50 watt
It's only $7.18 for it and is the proper one to correctly load the 5 volt line on the power supply.
Actually, I think it's enough, since there are two of them. At 2 ohms, you get 12.5 watts of power and since there are two, each only have to worry about 6.25 watts. I'm not exactly skilled in this, but I did look it up and most people say that when two resistors are used in series you double their power rating, as long as you use two identical resistors.
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I can't believe the amount of trouble you're going thru. Just rewire and be done with it.