The extruder controller is based on the Arduino Diecimila. It contains all the electronics required to drive one extruder, as well as extra electronics to drive a heated/automated build platform. It has built-in USB, so you can talk to it and program it with a normal USB cable.
The power MOSFETs are what control the extruder heater, build platform heater, and the conveyor belt motor. These little chips are beasts that can handle 10A of current. They can easily power the MK5 or 120mm x 120mm heated build surface.
They are labeled 'Heater', 'Extra', and 'Fan' respectively.
The pinouts are the same for all 3 MOSFETs, and looking at the board with the USB port at the top, pin 1 is toward the bottom.
PIN NAME FUNCTION
1 +12V Connected directly to the +12V power supply.
2 Output Connected to the drain of the N-channel MOSFET. When on, connects to ground. Otherwise, high impedance.
Accurate temperature measurement is critical for high quality 3D printing. Thermocouples are a really solid way to measure high temperatures. They are accurate, reliable, and high tolerance. They also have the side benefit of being easy to mount. Simply bolt the thermocouple to the side of your thermal core. This board is designed to be used with Type K thermocouples, a very standard type of thermocouple.
Thermocouples are polarized, so if you wire it up wrong, the temperature will not read correctly. The thermocouples we ship are color coded, so wire it up based on the colors.
It may also help to trim down the thermocouple leads so that they fit nicely in the terminals. About 5-6mm is the appropriate length for the bare wires.
PIN NAME FUNCTION
1 T- This is the negative side of the thermocouple. It should be Red.
2 T+ This is the positive side of the thermocouple. It should be Yellow.