This is another of the regular surface mount solder workshops I'm holding at vhs. In June we'll be building a 12 channel FET driver board for either Arduino or Raspberry Pi. You can find out more about VHS at vancouver.hackspace.ca.

At maker faire 2013 we were offered a donation of a large amount of SMD components. Amongst those components were lots of obscure semiconductors (like 4.096V regulators for a/d converters). Amongst the obscure semiconductors were some gems, including a partial reel of high current FETs.

I set about designing a board to use them and this workshop is the result. You're saving about $16 for the 12 FETs - they are SI4850, you can read the specs at http://www.vishay.com/doc?71146.

I'm limiting the FETs to 12 per person (ie. 1 board). You can buy an additional board with no FETs for the same price and split the FETs between them ie. you could make a 6 FET Raspberry pi board and a 6 FET Arduino board.

All of the channels are opto isolated. Four of the 12 channels on the board can be reversed - so you omit the FETs and use them as opto isolated inputs instead.

The board is designed to take 5V or 12V but can work at different voltages. There are also options to power the pi/arduino using the same power supply but you need to make sure you are within the limits of the device.

With appropriate external circuits the board can drive high current leds, dc motors, relays, solenoids etc. Each FET is capable of carrying 7A, the PCB is not capable of 12x7A however.

The soldering is fairly easy, only the resistors on the underside are small. Anyone with reasonable soldering skills can complete this.

Please consider bringing your own soldering iron as we don't have enough for everyone.