LED Taillights, Custom Made for the 914 Options

[Spoke]

I've wanted to convert my 914 taillights to LED for a while but never got around to it.

Finally I started working on the design of the taillights. This will be a single custom PCB for each side and will have all the LEDs and control circuits on it. One PCB will be used for both sides.

The plan is to remove the existing plastic reflector and bulb assembly and mount a custom board in its place. With proper standoffs, I should be able to mount the board using the same 2 screw holes that secure the reflector.

I'm trying to decide now how many LEDs to use for each purpose. Right now, I have 8 LEDs for the backup lights, 20 LEDs for the running/Brake lights, 24 LEDs for the turnsignals, and 4 LEDs for the side marker.

I've been observing modern cars with LED taillights and some use a few LEDs (like 8) and some a lot (+20).

I would like your opinions on how many LEDs you think would be good to use. On the board below, the LEDs are spaced about 0.7 inches apart. These will be medium brightness white LEDs. (I'll let the lenses provide the color).

The first cut at the board is shown below for the driver's side. The side marker LEDs will be right angle LEDs pointing out the side of the board. They can be seen on the extreme left side of the board.

If these work out, I could manufacture them for World members. One thing though, they won't be cheap. The LEDs are about $0.50 through Digikey and there are more than 55 LEDs on each right now. Plus there's 2 dc-dc converters for providing constant current for the tail/brake and turnsignal LEDs.

Cheers
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[Spoke]

Here's a close up of the outside end of the board. The side marker LEDs are mounted on the edge of the board.

The circuitry is a constant current dc-dc boost converter to drive the turnsignals. This will provide constant current regardless of battery voltage which we all know varies all over the place in the 914. This converter and associated components represents about $10 cost but will give superb operation.

The outside edge of the board is cut at an angle on the top and bottom to allow the same board to be used on both sides.



This little T cut-out is for the webbing in the lens cover. The one mounting hole is very close to the cut-out. I'm hoping to not have to trim the webbing but that wouldn't be that bad to trim the webbing a bit.

The 5 holes at the top are to solder the wires from the enclosure. I'm trying to think of a better way to connect the wiring to the board.