I wanted some auxiliary spotlight for my car, for use in particularly dark highways (they do not have streetlights) and found that the commercially available options were not to my liking.
Baja Designs was ridiculously overpriced to just be a non-DTP aluminum board, Diode Dynamics was using emitters too cool in CCT, and MTNLiteBar’s products were not the right form factor.
So I decided to give my attempt to make something better than what’s available and do it on a budget of less than $50, in the spirit of the forum.
I started with some LED 3" pod spotlights from Aliexpress, which I got a pair of for $20. The build quality was acceptable for the price, being made of cast aluminum with a thick polycarbonate lens and a thick shelf/heatsink in the back. The reflectors are plastic, but seem to be fine for now. FW1A for scale.
Unfortunately, the board is a buck driver (wired as 2S) on a thin aluminum MCPCB with some terrible 3v 5050 LEDs.
Contrast enhanced to better see the traces:
I considered modifying the original board by just swapping the emitters to tint-mixed W5050SQ3, but the controller is a weird one where there’s only chinese datasheets and I was out of my depth when it came to increasing the current.
Instead, what I am currently going to do is to put in 4 20mm DTP MCPCBs wired as 2S in each pod and use an external constant-current buck driver, set to 20A which will be shared over the pair of spotlights, meaning 5A per emitter. I believe this should be fine as long as I only use the lights at speed, so that the airflow cools them.
The driver is a generic “600W 12-75V DC” constant-current buck regulator ($10) that will probably end up near the spotlights so that the high-current wires are shorter, possibly inside a modified tupperware box to give it some water resistance. I’ll probably put a relay in there too, so that the switch in the car only switches a low-current signal.
The emitters will be Lumenpioneer (LMP) W5050SQ3 in a 3000/6500k tint mix, which has already given me good results in a D4Sv2 (4300k Ra70 with neutral DUV) mounted on Convoy 20mm DTP MCPCBs ($16 for all 8). This should roughly match the color of my HID low beams as well.
I am currently waiting for the new parts to arrive, but figured I should post about it to see what BLF thinks, and in case anyone has an idea I may have overlooked.
I will be updating when the new parts arrive, in a few weeks.