Renoir's RepRap Heater Board

This is a breakout board for an arduino that boosts the 5v signal from the arduino output to a high-power 12v, suitable for running RepRap heaters, fans, heated beds, etc.
The IDC will plug into my Arduino Mega Shield ( http://www.thingiverse.com/thing:3308 ) and the power socket is designed to accept standard PC disk drive power plugs.

The signal from the arduino is amplified using a MOSFET - I used FDB8880 ( http://uk.farnell.com/jsp/search/productdetail.jsp?SKU=1228327 ) at 60p each, whic