# Hi Chris...

July 21 2011 at 5:46 PM

YC

Response to You're right...it's not current-controlled

Here's what I have on the cutter. Its 4.5" of 26 ga NiCh wire. I found a similar chart that that told me 12 inches of wire gives 2.57 ohms. And for a cutting temp of 600 deg. I need 2.14 amps.

http://hotwirefoamcutterinfo.com/Hot_Wire_Foam_Cutter_Info/__ETheory.html

Now if I use 4.5" does that mean I'm getting .964 ohms or with shorter wire am I getting 6.8 ohms?

Then in the first case V= 2.14amps*.964ohms=2.06 volts

Or in the second case V= 2.14amps*6.8ohms=14.5volts

Based on my early use of the cutter, 12 volts and 2amps cut foam, so maybe the second case is the valid one?. So even a 2 amp 15 volt supply may be better.

I am no electrical expert at all. I did burn up the 24v 2 amp doorbell transfomer running off a router speed controller. I also burned up a router speed controller by itself. So I am gradually investing a lot into this project, so my hope is to find a good power supply for this purpose.lol I guess if I could find a power supply that gave a constant 12-15 volts at 2 amps I would be good?

Maybe this?