There are some good instructions on youtube. This board is a buck or step down converter. This version is setup for the charging of lithium batteries.
These instructions are for the 12v power adapter supplied with the Filastruder.
1) Connect the 12 volt power supply wires to the board using the connectors on the left hand side of the board. Watch that you have the correct polarity (marked on the board). Make sure you have no wires in the output connector (right side) at this stage so there is no load on the circuit.
2) You should now see the LED display light up. The output button on the right of the LED moves the LED through the modes of the LED display, alternating, voltage in, voltage out, amps out and power out. The input button on the left of the display turns the display on and off. Press the right button until the input voltage display is shown, this should be around 12 volts. Now press the button until the output voltage is shown.
3) The CV and CA adjustment screws are at the top of the board, CV (voltage) is the left one CA is the right.
4) Turn the CV screw clock wise until the output voltage is roughly the same as the input voltage.
5) Connect the heater wires to the output + and - on the top right of the board. This adds a load to the circuit.
6) Select the output button on the right of the LED until the amp output display is shown.
7) Turn the CA screw anti clockwise or clockwise until the amps are set to around 1.6 amps.
8) If you select the output voltage LED display now using the right output button you should have around 6 volts. This is now your starting point for the Filastruder. You can reduce the voltage by turning the CV screw anti-clockwise this will reduce the voltage and auger("drill bit") speed.