Calculating heating effect.? Answered
I have been experimenting with making a hot wire foam cutter. This needs to be at least 600 mm wide. I have to hand a PSU capable of providing 14 volts at 2 amps (or slightly below) This is 28 watts.
Now the question i would like to calculate the heat the Nichrome wire will reach at any given wattage but have no idea if I can do this.
I have several wires that work to different levels, resistance of 30R, 4 R, 137R at the length I am using.
Any one any ideas how to calculate the temp or are there too many variables?
So far I have worked empirically and arrived at the conclusion I need either around 18 volts at about 3 amps or I need a wire with a resistance of around 7R to suite the power i have available. I do know that the 20+ watts I am generating is just heating the wire to the melting point of the polystyrene foam. The melting point of the foam is apparently around 220 to 240 deg C (internet)
At present it isn't cutting fast enough for my project. which required producing 5 mm thick sheets of foam with a reasonable consistency. i am cutting them from a 50 mm thick 1000mm x 500 mm block.