Door lights

[Bitsyncmaster]

When I first bought my car the first thing I changed was installing LEDs into the door lights. That was over 12 years ago and I have always been thinking of updating them. This first design used 4 LEDs they were using in street lights at the time. That string with a constant current of 30 ma.

So I bought a set of NOS door lights to start playing.

It's been so long since I've seen an NOS bulb in a door light here are some photos. The bulb has no part number but is labeled "JAHN UK".
At 12.50 volts it draws 0.371 amps which is 4.64 watts.

[Bitsyncmaster]

Here are some photos of my old LEDs. I also painted the insides of the rubber cup with aluminum paint.

[Bitsyncmaster]

I've been looking at many different vendors red LED chips (size 0805 footprint) and they just do not seem very bright and when running the max current of 20 ma. the color seems to change more orange if looking directly at the chip. So I'm still buying more LEDs to test.

I also laid out a prototype circuit board which was suppose to arrive Friday but they shipped me another customers circuit boards by accident. That new board has 16 LEDs spaced in a circle which I plan to use as 4 strings of 10 ma. each. I could run each string up to the max of 20 ma. but then the 6 door lights would 0.48 amps which may be a little high draw for a long car show but that's just resistor value changes to set the current.

By the way, laying out that new circuit board is the first time I've used "sin and cos" since school. I had to get X/Y coordinates to place the LEDs in a circle. Calculators are great in that you can use degrees now instead or radians. Much better than a slide rule when I was in high school.

[ZLoftsgard]

I've been looking at many different vendors red LED chips (size 0805 footprint) and they just do not seem very bright and when running the max current of 20 ma. the color seems to change more orange if looking directly at the chip. So I'm still buying more LEDs to test.

I also laid out a prototype circuit board which was suppose to arrive Friday but they shipped me another customers circuit boards by accident. That new board has 16 LEDs spaced in a circle which I plan to use as 4 strings of 10 ma. each. I could run each string up to the max of 20 ma. but then the 6 door lights would 0.48 amps which may be a little high draw for a long car show but that's just resistor value changes to set the current.

By the way, laying out that new circuit board is the first time I've used "sin and cos" since school. I had to get X/Y coordinates to place the LEDs in a circle. Calculators are great in that you can use degrees now instead or radians. Much better than a slide rule when I was in high school.

Thanks for the information. I was curious how bright the new setup will be? Similar to your previous LED setup?

[Bitsyncmaster]

Thanks for the information. I was curious how bright the new setup will be? Similar to your previous LED setup?

When I get the circuit boards I will post photos. The problem with the LEDs that plug in is it puts the dots right next to the lens. My board will remove the socket and the board will be glued onto the bottom of the rubber housing. What can be done is you reuse the wires you cut off the socket but that would require you solder those two wire to my board or I can solder some short wires and you would join them to your old wires. The NOS configuration has a two pin connector on each light.

[Rhye]

The problem with the LEDs that plug in is it puts the dots right next to the lens. My board will remove the socket and the board will be glued onto the bottom of the rubber housing.

How about using a large, warm COB LED and running it with a very low current, like 5% of max or so?
65038
It should give a fairly uniform pattern when placed close to the lens - you could still use a stock bulb socket. I'm only not sure what the efficiency would be at a very low power level.

[Bitsyncmaster]

How about using a large, warm COB LED and running it with a very low current, like 5% of max or so?
65038
It should give a fairly uniform pattern when placed close to the lens - you could still use a stock bulb socket. I'm only not sure what the efficiency would be at a very low power level.

Ive found using more LEDs at less power is better when back-lighting. If you have a colored lens than you want to use the same color LED for best efficiency.

[Timeless]

Dave, I'm sure you know these:

http://deloreana.com/

[Mark D]

Dave, I'm sure you know these:

http://deloreana.com/

I've got those in my car and really like them. I have a thin piece of milk jug plastic behind the normal lens to help diffuse the LEDs.

Not the best photos, but you get the idea

The left photo has no lens and on the right I"m holding the diffuser plastic half on / half off the regular lens

http://dmctalk.org/attachment.php?attachmentid=65039&d=1606157718

[Jonathan]

Dave,

You ever look on any of the Pinball parts webstores for what they offer for LED bulbs? Usually lots of different shapes and sizes, bases, lens colours, dome styles, etc.

https://www.titanpinball.com/index.php?route=product/category&path=17

[Bitsyncmaster]

Here are some photos with 40 ma. total current (12.5 volts). Looking straight on to the lens it's very even but when you get to some angles you can still see the ring of LEDs. One photo is no lens which shows the 16 LEDs on the round circuit board.

[Bitsyncmaster]

Here is a side by side inside house at 12.50 volts with NOS (incandescent) and my new LED board. One is in the dark, other is with lights on (note I have LED lights inside my house). The red color is really the same but my camera displays not true colors with LEDs.

I will have to do a compare outside. Usually LEDs don't look as bright in sunlight as incandescent.

[Bitsyncmaster]

I made up a board with amber LEDs and they look more red than amber. I wonder if my supplier sent the wrong parts. So now I'm not happy with the red (look a little orange) and the amber (look a little red).

The lens has a low pyramid shaped top surface. I'm thinking that is causing the four images of the set of round spaced LEDs I see when looking at an angle to the lens. I may try to machine one flat.

Back to buying more LEDs to test.

Red is 665nm, orange is 630nm, amber is 590nm.

[Dhennick99]

Once you have a design finalized, I'll be a day one buyer. Your upgrades are the best!

[Bitsyncmaster]

Well I found the amber LEDs that match the color of the lens. I sanded the pyramid off the outside of the lens with 120 grit wet sanding. That did eliminate the image of the circle of lights when viewing at an angle. It makes the lens look frosted with that grit of sanding. I think I will try sanding with finer grit and putting a polish on that surface just to see the result.

Well just tried with the lens reversed (flipped so diamond pattern is outside). I love the look of it now.

I was running my old door lights with it flipped also.

Now sanding does take a lot of time. The plastic is very hard and you don't put a lot of pressure on it when sanding.

[Bitsyncmaster]

Did some more experimenting. It does not matter which side is outside with the sanded surface but running it inside will keep oils off the "frosted" side which would remove the "frosting").

I tried the painting of the walls of the black rubber and not sure if that helps anything. I would need to have both black and silver side by side to compare. That will come after I get the production circuit board done.

I've been thinking of a better way to produce the production boards. Yes I could order round boards at about $3 each but I'm considering getting an array which is many board made from one large board. The array is V scored so you can break the boards apart. Of course you can not break apart a round V scored board. I will then have a hole in the center of the board and I can mount 10 or more on my lathe and turn the boards round.

[Bitsyncmaster]

Well all forms of shipping are really bad now. I waited for another LED I found where the specs looked more like what I needed. That shipping took 11 days. It was finally shipped to our local distribution center then it got shipped to DC. UPS and FedEx are the same.

Anyway those LEDs are much better as far a having a red color than most of the others more amber than red. The spectral frequency from red, amber and orange is very narrow. Also the eye does not see red as good as the higher frequency light so manufactures looking for the higher lumens in their specifications want to call amber red. Nothing seems to beat the old 5 mm red LEDs I used 15 years ago that were manufactured for traffic lights (now obsolete).

These new LEDs don't seem to look much brighter at 20 ma then 10 ma. Since they are rated to 30 ma max that lets me just use a resistor to set each string current. Now if you want to run max current you should use a regulated current source. I'm still not ready to order production PCBs yet since I may still keep searching for a better LED.

[Bitsyncmaster]

Well I've decided the LEDs I got on my last order are the best ones yet. The red color is good and orange are good for the amber lights. I went ahead and ordered circuit boards. The boards ended up costing $1.08 each which is higher than I guess it would cost. I had to pay NRE charges getting break away boards. I don't expect many sales of these since it requires the customer pulling the LENS, the bulb and socket, then cutting the socket off and soldering the two wires on my board. Then if they want to sand off the pyramid off the lens to get really even light.

Boards will take 4 to 5 weeks to arrive. I did put a center hole in the board so I can machine (many at a time) round on my lathe.

[Bitsyncmaster]

Well I got the new boards and installed them in my car. Result looks very good but I don't expect many owners to want them because it requires you cut your lamp socket off and solder the wires to my board. I had the rubber pulled out also so I could put some hot glue where the wires enter which holds the board in.

NOS rubber seems to be the same condition of my originals so not much reason to replace the rubber or lens.

Sanding the lens flat will probably help with any LED or bulb. It does frost the side to disperse the light. I ended at sanding the final result at a 45 deg. to the sides thinking not to follow the molded horizontal and vertical pyramids cast into the lens. The lens is a hard plastic so it takes a long time to hand wet sand it. I did not chance to use a machine to sand them since it is hard to hold onto. I put the lens in with the sanded side in. That way no oils from you fingers can get on the frosted side. Also sanded the sharp edges off the sides to help when the lens is removed or inserted.

I did paint the inside of the rubber with a silver paint but not sure if that aided anything.