12V supply for LEDs and fans

[joergen 2]

My UM was missing a decent 12V supply for add-ons and extensions, so I hacked one together:

You can get +19V from the terminal screw from the bed heater, and ground from other places (I soldered a blue screw terminal to the right side of the UM PCB). A crude daughter board with two LM7812 as voltage regulators creates two 12V bus rails with 1A each. since the LM7812 is a very inefficient regulator (it's dumbing up to 7V x 1A as heat), a heat sink is mandatory. a single LED strip can consume as much as 200mAh at 12V, so make sure you don't overload the bus. (I have 5 LED strips running and 2 fans).

The daughter board is held in place by a simple printed square PCB holder and some hot glue between the PLA and the plywood.

This is good for fans: http://www.thingiverse.com/thing:10064 and http://www.thingiverse.com/thing:9617) and 12V LED strips.

Planned upgrades: using a proper switching voltage regulator to cut down on the wasted energy/heat