Dimmable Cafe Light Prototype

I received an order to provide a working sample to test Nichia 3000K 144AM from my friend for his client. I decided to make a rather stylish prototype using scraps found in my workshop. The sample light must has easy access to replace the LED and optics using various MCPCB and LED setup. And the most important thing is it can be tested in actual working conditions for several days.

I made two prototypes, one for the actual request and the other for the marketing guy to keep for his presentation in the future. This is a good chance to show them the difference between “common” CRI 80 standard vs CRI 9080 in real condition.

I have some big aluminum 40cm reflectors like this from my former company inventory (wedding project). Later I used the smaller 35cm for easier packing. The idea is to make the reflector as passive cooling radiator. The large surface area should be enough to cool up to 30 watt LED module.

The dance floor style reflector will not be a good idea. Will have to be painted matte white for uniform beam pattern

Cleaned all the nickel coating to expose bare aluminum for better heat dissipation, some brass coating still remains (completely removed later).

Matte white paint for uniform beam pattern.

Made two base plate from 20mm thick 5056 aluminum plate. Tapped and drill 8pcs M6x1 thread to mount the reflector. It’s a bit overkill but I just want to make sure enough clamping force (for good heat path) between the base plate and the reflector. The thin (0,5mm) reflector’s mounting area where the base plate bolted made by somewhat crude machining process. The reflector material is also very soft and the one of the easiest way to get good heat path is by increasing the clamping force.

Left: straight from the lathe. Right: lapped to #1000 using grit SiC. Final finish is lapped down to #2000 grit sandpaper on glass surface.

The backside of the base plate was roughly machined using 45° HSS blade 0,5mm deep.

The internals are installed. I used 8-24V buck driver running at 2,8A at max. Connected to a 250K potentiometer resulted in 0,4 –18 watt adjustable output. Most of the light beam shaped by the 20mm TIR optic. The white reflector just to aid directing some of the spill leaked from the TIR.

Power supply using old DC power adapter from my broken laptop:

Left: 1 x 144AM sm305 E1100 R8000. Right: 4x E21A sm303 D200 R9080 (6V config)

- Clemence

I really should wear my glasses. I read the title as dimable car light and read through the post without it making any sense at all. The last few pictures gave it away. :person_facepalming:
Nice work as usual. :slight_smile:

Yes you can use it inside your car too! :laughing:
As long as the input is 8 - 24V

- Clemence

I wonder how much it would cost ..... to have some woman come in and clean your shop ?

i keep thinking wireless remote controls on lights like these

Cool project ..

A mans cave cannot be cleaned by a woman. They can find lost items that have disappeared into thin air though.

Yah, well, on one of the knife threads, someone was talking about his “Arius” ( A r i u s ), and I kept reading it multiple times as “Anus” ( A n u s ). :person_facepalming:

Rather ironic that the offending font is “Arial”, or should I say “Anal”?

Wow, that’s an incredible difference for 2 lights that side-by-side look almost the same.

Btw, what does the pot do that controls the brightness? Not familiar with the driver… parallels the sense resistor?

Thinking… for even better heat-transfer, just a dab of AS5 on your finger and running it around the periphery where the disc meets the reflector might shave some thermal resistance off the unit.

They’re totally different. Everything looks better under the R9080.
Adjustable driver made by Anatoly in Russia. Bought them from his ebay store years ago. Yes, it adjust the sense resistor.
As usual, I always forget to buy the AS5 and keeps using my Moly-graphite bearing grease. A full night running at 30C ambient resulted in less than 42C base plate temp. This will definitely makes the purchase of AS5 delayed much longer.

- Clemence

Nah, I meant the shot looking at both lights side-by-side, they both looked “warm”, and about the same color.

But the 2 different shots of each one on individually made an incredible difference.

I’m sold. :smiley:

Cool project!

Do you have a source for those buck drivers?

I’ll post it in the OP. I forgot where I bought it. Checking my old email archive……
EDIT: got it! Looks like he’s selling a new upgraded driver with screw mounting holes. Great, no more thermal adhesives.
Here’s the link to his store: Security Measure

- Clemence

such a cool project, didn’t expect the lights to be this bright.

awesome work!