# Need help for my hot wire cutter



## Erebus (Jul 28, 2009)

I got a power supply from my neighbor (pictured below) and I hooked it as I thought it was supposed to. I put the positive to the top of the wire, and the negative to the bottom. I have checked the connections with a voltage reader and I am getting power to both alligator clips but the wire won't get hot. I am using 0.016" plain steel (guitar string) wire. I let it sit for about 5 minutes and still nothing. I put the power supply at roughly 7 volts. Do you know where my problem is?


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## Erebus (Jul 28, 2009)

I think I found the answer. This power supply only puts out .1 amp max. How many amps do I need to make it work?


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## fritz42_male (May 5, 2009)

The thread I read suggested a 12V 60Watt setup using a halogen downlight transformer. This equates to 5 amps.


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## pshort (May 6, 2008)

The current limit on that p/s might very well be kicking in...


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## spinman1949 (Jun 29, 2009)

*No amps.*

You pretty much answered your own question. 7 volts at .1 amp equals .7 watts. What kind of Power Supply is that ? .1 amps ? That is much lower than even the smallest WART.


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## Erebus (Jul 28, 2009)

I have no idea what they used this for. My neighbor gave it to me. I can switch it between A and B Range but A range is a max of .05 amps and B range is .1 amps. Guess the third time the charm. We origanally tried to use a tattoo machine PS but it kept going in fault when we turned it on. Guess I will just have to build a GOE one.


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## pshort (May 6, 2008)

Looking it up on the web, that power supply should be good for up to 5A on the 0-36VDC range, up to 10A on the 0-18V range. My guess as to your problem is that your wire is such a heavy load that the supply is limiting the current to those low values to protect itself (foldback current limiting).


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## spinman1949 (Jun 29, 2009)

*Or Direct short protection.*



pshort said:


> Looking it up on the web, that power supply should be good for up to 5A on the 0-36VDC range, up to 10A on the 0-18V range. My guess as to your problem is that your wire is such a heavy load that the supply is limiting the current to those low values to protect itself (foldback current limiting).


A piece of wire is a direct short. I doubt the ohm's are much of anything. Maybe the power supply has a perceived short protection circuit.

You might want to test the power supply on something like a brake light from a car. See if it will light one of those?

PS I just looked up the specs as well. I suspect your unit is a bit older. The new new units don't show the three prong outlets in the front and mention a thermal magnetic circuit breaker. Yours shows a reset button. That looks like a circuit breaker. Is that popping out ?


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## Erebus (Jul 28, 2009)

It was made on January on 1985. It's older than me. Ha. I am not sure if the circuit breaker thing is popping out or not. But I hooked it up, and I used a meter reader with it and it had power. Would it reset itself when I turn it off? I will push that button when I get home and see if that works. How long does it usually take to heat the wire up before it will cut foam? Thanks for letting me know that it is 5 and 10 amps. I don't know why it has a . infront of it. It is all squished to gether so I guess it is there way of using it as a space.


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## Erebus (Jul 28, 2009)

OK. It works now. I put my meter reader to it on the amps setting and I found that I have to turn the nob way down for it to work. At first the string started to turn red so I turned it down and it works great. Thanks for you help.


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