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I have a 120 >12 volt power supply and would like to be able to adjust the out-put for use in foam cutting Answered

120volt ac >12 volt dc that I would like to regulate tho output as a variable instead of  fixed 3-5-12 volt 

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Yonatan24

Best Answer 2 years ago

You need to put a proper dimmer at the output of the power supply. Search for 12V dimmer on eBay.

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dogscatsand9752

2 years ago

Got a 12-24 volt dimmer at Fry's electronics works great Thanks go out to everyone that worked on this

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dogscatsand9752

2 years ago

OK so if I use a dimmer (120 volt) it of course change the output at the power supply. my power supply is just a simple 120 ac >12 volt dc

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Downunder35m

2 years ago

I have done a fair bit of foam cutting back in the day and I still wonder how people like to complicate things for no reason ;)
There is a very basic rule that helps to avoid problems with the power supply:
You select the wire lenght and diameter according to your power supply and heating requirements.
If the wire is getting far too hot then it is too short or too thin.
If the power supply overheats or fails then the wire is too thick or too short.
Quite simple math according to Ohm's law.
Depending on how you design your cutter you can simply leave some extra wire to put the clamp on and adjut the output that way....

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steveastrouk

2 years ago

What is your power supply ? All you need is a transformer and a dimmer to drive the transformer.

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dogscatsand9752

2 years ago

OK if I had a variac I would not need to adjust the out put of my 120 volt ac to 12 volt dc thanks for the answer. can't I just put a potentiometer at the output

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steveastroukdogscatsand9752

Answer 2 years ago

No, because the potentiometer has to dissipate as much power as your wire, or even more.

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dogscatsand9752rickharris

Answer 2 years ago

That,s great but I dont read schematics was hopping for just a simple fix

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iceng

2 years ago

Here is a very simple circuit, how to use it, how it is wired and examples.

I use gloves to avoid burns.

Click on the pics to see the entire Image.

styrofoamCutter.jpgsplitBolt.jpgTool1 round.bmpTool2 trim.bmpTool3 knife.bmpFirstcutting(25).JPGTool molding.pngVaric.JPGXFMR1.JPGXFMR2.JPGHotCurrent.JPG