I have finished my Arduino based pulse width modulated (PWM) hot wire cutter controller. It allows precise USB or analog temperature control of a hot wire of length from 10cm to 2m for use with manual cutters or CNC based cutter. The PSU is extermal (battery or PSU) The 12v power is attached to the GND and + 12V terminals. The + to the hotwire is attached on the red terminal on the top. The current return thru the FET is connected to the black return terminal. An FTDI board can be attached to the Arduino thru the "programming window".
What do you think :) ?