LED Night Lamp

A bit more of an artistic project I had a play round with to make use of a 10W LED and driver combo I got off eBay. The files are here: http://www.thingiverse.com/thing:1318807

The bottom piece was designed in OpenSCAD, the top piece - the "box" - was designed in Blender because it was originally meant to have complex patterns on the inside which would only be visible when lit.

Finished product:

The 10W LED is still surprisingly bright when covered, the colour output of the LED is white but the plastic box unfortunately yellows the light a lot.

Make sure you fit the hidden captive M3 nuts on the back side of those screw holes. This can be done by poking a long M3 screw through the hole, threading a nut on and then pulling the nut down into the nut trap. If the nut trap is undersized, heat the nut up with a soldering iron then quickly pull it into the nut trap.

Small 12v switch mode PSU on the left with a ~0.8A current limiter integrated which is important for powering LEDs and not having them burn up due to their non-ohmic behavior. The quality of the PSU isn't bad either, there's filtering and proper separation between high and low voltage, I didn't inspect the transformer's wingdings but I hope it's of the same quality inside as the rest of the board. The LED "chip" is on the right.

The makeshift bending process for the dual aluminium heat sink/outer casing. Had to keep that protective wrap on till the end so it didn't scratch! Those edges where the wrapping is curling up did get scratched though - turns out toothpaste is a scarily effective (and still pretty coarse) abrasive if you don't have anything else to polish with.

Oops... something went wrong, but this wasn't totally unexpected given the tooling. More important than the total height of the base or the slightly mis-matched bend radii was getting the sides level so I cut down the left side.

Here it is drilled and re-sized through much chiseling, and sanding. The amount I had to take off was a bit small for a hacksaw, too large to sand and don't even think about grinding aluminium!

Make the aluminium outer first and see how it comes out then modify the printed base to suit the errors - that's why it's parametric. In this case the radius has been made larger on one side and the overall height reduced. Some gaps are visible, and the aluminium isn't flat in the middle so viewing distance, angle and favourable lighting are late additions to the BOM.

All wired up, the PSU is hot glued to the base because it has no mounting holes anyway. Since the device runs on 240V mains and has exposed metal, a three pronged plug and lead with earth are crucial - even more crucial is to connect the ground lead to the metal casing: note the bottom right screw pillar which was made slightly shorter to allow room for a connection. I'm not an electrician or nuanced in electrical codes - so wiring is your own responsibility and most LED drivers from China aren't certified either. I don't leave this light running for long periods of time unattended.