This is a control circuit for a Hotwire foam cutter. Using ~6inches of nichrome wire and running some current through it we can cut .5inch thick foam. Eventually this will use the current feedback from the mosfet to better regulate the temperature of the wire.

This circuit utilizes a high current MOSFET (basically a switch) to vary the amount of current flowing through a piece of nichrome wire. The idea is that when the nichrome heats up we can use it to cut through foam. Using feedback from a potentiometer an arduino provides a square wave signal with a variable duty to the mosfet. By changing the duty (% of time signal is on) the temperature of the nichrome can be controlled. The included arduino sketch limits the MAX_DUTY to 15 as any more caused our nichrome wire to get too hot and melt. You may need to vary this value. Happy Building. CAUTION: This circuit uses a 20v supply, DO NOT hook this directly to your arduino, it will blow up. Also be careful as 20v can cause severe heating and or damage to electronics if incorrectly hooked up!

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uaneme 5 years, 1 month ago

Is this actually build and tested or does something go wrong when i try to open it in a more recent version of fritzing? Some powerrail connection are wrong. (Ground of the LM conncted to +5V for example) Why not use 12V instead of 20V?