LED Brake Lights

[spoke]

Originally Posted by A horse with no name

After reversing the connections within the R signal light, the problem was resolved.

Awesome!

Sometimes the most frustrating electrical problems are stem from some simple mistake.

What do you think about the diffusers? Looks like you've used them. One side of my car has one and the other not. It makes the biggest difference when the lights are off as you can't clearly see the LEDs like without the diffuser.

[A horse with no name]

Yes Jerry, 'Happiness is' when solving, particularly electrical issues...As you noticed, I did use the diffusers that you supplied...They are even brighter without the diffusers but I personally prefer the look with them... I am though looking forward to wiring them so as to have them working in conjunction with the signal lights!

Again, thanks Jerry for your fine products, and especially your assitance in resolving the electrical issue that I was experiencing.

Take care

[dannyg911]

Got my rear brake / side markers installed and they are GREAT. Super easy to install and at least double or triple visibility. I did the front DRL a couple of months ago and now I am moving on to the side markers with the turn signal wiring. I can’t say enough about spoke (Jerry) and his products

Before

After

[spoke]

Still working on the 356 front lights. Recall that I destroyed the switching MOSFET and the PCB on the first attempt.

The switching converter board was redesigned to use a much larger MOSFET with a D2PAK package with much lower ON resistance (0.0056 vs 0.350 ohm). Also replaced the inductor with one with much lower series resistance. Resistance in these components means power loss and temperature rise. Also added a heat sink around the MOSFET.

Here's the new converter board mounted on the LED board. Initial tests with the assembly in the lamp enclosure showed very high temperatures with no airflow. A thermal probe on the MOSFET case showed temperatures above 120C and ambient temperature inside the fixture at almost 95C. At this point the entire circuit is burning a bit over 20W.

Concerned about the high internal temperatures, I reduced the LED current from 0.35A to 0.275A and power reduction to about 16W. Temps now max out at 113C for the MOSFET and about 80C inside ambient temperatures with no airflow. With low airflow of about 10MPH the temperatures dropped almost 15C.

The lamp has been run for about 40 hours already and seems to be operating ok.



One thing I'm trying is to try to thermally isolate the converter board from the LED heatsink. This is done with a blank circuit board mounted between the LED heatsink and the converter board. The blank circuit board can be seen in this picture already mounted on the LED heatsink. Not sure it helps but it was cheap to install it.

[spoke]

The first light is working well. About 50 hours running with voltages between 10-16Vdc. Worst case is 10V with current about 1.6Amp. MOSFET case runs as high as 113C at standstill and as low as 90C with airflow as car is moving.

Getting the 2nd LED board done. LED Lenses and holders are glued in. These lamps are bright and pretty well focused. The light pattern is below. The light pattern is wide and someone directional in the vertical direction. I think the lights will need to be pointed a bit downward on the car to not blind on-coming traffic.

[Arne2]

Originally Posted by 69porsche

Arne,
So in order to ensure there's a significant contrast between brake and tail light, you removed the R3---How's that working for you? and how were you able to remove the R3 and did it take any other skills or modifications to the existing board?

I just happened to see this question, and I see that Spoke answered the how-to part.

I actually went one step farther and removed a second resistor from each board a few months ago, to increase the difference even more. Very pleased with it now. Tail lights still appear to be brighter than with incandescent bulbs, and there is a LOT of difference when I step on the brakes now. Totally happy.

[spoke]

Finally finished the 356 front running lights. Assembled the wire harness. I tied a knot in the wires then added several layers of shrink wrap to make a strain relief.

These lamps burn about 16W and are as bright as the low beam on my daily car.

The owner of the lights asked about the cost of the pair of lights. Because these are prototypes, the cost to him is zero. For me it was a great learning experience since I did not have experience doing a high-power LED lamp like this.

The owner asked if I could build these in 6 weeks and I said I'd try. It's been about 6 months so I guess my time estimate was a bit optimistic. As one of my colleagues once stated: "You can't schedule invention".

[spoke]

Another LED project I'm working on. This one is for a former 911 owner who has purchased a Ferrari 348 and is doing some custom brake/turnsignal fixtures.

The brake and turnsignal will use the same board. The turnsignal lens shown here has the reverse light in the middle of the turnsignal. The board is pretty large at just over 5 inches in diameter.

The brake/running light and turnsignal will have 100 LEDs and the center reverse light has 30. These lights will be bright as they have over 2x the number of LEDs as the 911 LED brake.

When configured for the brake/running light the center white LEDs will not be populated. This is ok since the center of the brake lens is a reflector and not transparent to light.

[boxcarracer]

A huge thank you to Jerry for his patience and expertise in my project. Buttoned the custom taillights up last night; now it's time to work on the final touches to make everything come together.
The video really doesn't do them justice, but here it is (it also helped me realize I have a burnt license plate lamp):
https://youtu.be/TAHINSq2OAE

[RocketWrench]

Originally Posted by spoke

Got the first set of front sidemarker boards built and installed on my car. They look a lot better than I thought they would.

Because there no dispersion qualities to the lens, the 48 LEDs are quite visible either on or off although it looks ok either way.

The weirdest thing about this board is I started out thinking of just a sidemarker board like the rear which has 12 LEDs and ended up with a front turnsignal board with 48 LEDs and capability to be very bright.

When I put 12 LEDs on this board they look lost. So I increased the LEDs to 30. Still a lot of blank space. Then up to 48 LEDs where this board is. In the end, all I ended up doing was redesigning the first front turnsignal board I made with 48 amber LEDs. Duh.

To keep the running light brightness to the same as the front turnsignal, I used the same resistive drive network. This means the LEDs can be operated at a bright level for turnsignals as well as the dim running light level. So if someone wanted to do some rewiring on the front of the car to run turnsignal power to this board, it would also flash with the turnsignal.

For connection to the car's running light power, the boards will come with a BA9 bulb base connector to connect to the existing sidemarker bulb socket. There will also be an extra red wire which will be curled up unused. The red wire would allow the sidemarker to double as a turnsignal if the car wiring is modified to bring turnsignal power to the sidemarker enclosure.

Spoke, can you make lenses too, or do you know anyone that can make them?

The reason I ask is I was refitting your indicator LED boards following some repair work, and it occurred to me that a single wrap-around lens for the front of impact bumper cars would look a lot neater than the two hard-to-align single lenses side by side that we currently have...?

Also, I am about to start my Datsun 280Z project and wondering if you might be able to help?

[spoke]

Originally Posted by RocketWrench

Spoke, can you make lenses too, or do you know anyone that can make them?

The reason I ask is I was refitting your indicator LED boards following some repair work, and it occurred to me that a single wrap-around lens for the front of impact bumper cars would look a lot neater than the two hard-to-align single lenses side by side that we currently have...?

Sounds like an interesting idea to have one large lens. I've found the sidemarker lenses to be a pain to get them seated and screws started. I haven't done anything in plastic like lenses and fixtures.

Also, I am about to start my Datsun 280Z project and wondering if you might be able to help?

Sure I'd love to make some LED boards for your 280Z. Do the lenses unscrew from the fixtures like the 911? I need to get inside the cavity to install a board. You would need to send me one of the fixtures. Post some pics if you have them. PM sent.

[Satanas]

Originally Posted by spoke

I tried putting a piece of fluorescent lighting diffuser in front of the front sidemarker.

It definitely hides the LEDs especially when not lit up. Not sure of the look when lit. I'll have to see it more outside in the dark.

Hi guys,
Please let me introduce myself and participate in your thread.
I'm Eric from France and have a 1987 3.2 since more than 10 years. I am a member of this French website that some of you may allready know: www.type911.org.
I'm impressed by all the upgrades and improvments that you are doing on different threads.
Talking about DRL, I've done this kind of modification on my car.


With turn light ON


You can see the video and explanation on the following link:
https://www.type911.org/blog/?idmembre=150

Sorry it's in French...

[PabloX]

Spoke, have you done anything with Chip On Board LEDs? If you do a set for DRLs, I'd be very interested.

[RSBob]

Santanas. Beautiful car. Wish I knew French.

[Satanas]

Thank you RSBob,

You should try Google Translate, it works pretty well...:-)

[spoke]

Originally Posted by Satanas

Hi guys,
Please let me introduce myself and participate in your thread.
I'm Eric from France and have a 1987 3.2 since more than 10 years. I am a member of this French website that some of you may allready know: www.type911.org.
I'm impressed by all the upgrades and improvments that you are doing on different threads.
Talking about DRL, I've done this kind of modification on my car.

Very nice work adapting the LED bulb to the front turnsignal bucket. The perfect positioning allows the top, bottom, and side LEDs (by your orientation) to reflect light towards the front as the reflection of the LEDs is visible in the picture.

My only suggestion if you happen to change your setup or others want to follow your installation is to remove the ballast resistor and change the OEM flasher to LED-compatible EP26 which is readily available online and in some auto parts stores.

[spoke]

Originally Posted by PabloX

Spoke, have you done anything with Chip On Board LEDs? If you do a set for DRLs, I'd be very interested.

Until you mentioned COB LEDs, I had not seen them. Did some searching on Digikey and they have a wide assortment available.

It looks like the Chip On Board LEDs are small LED chips placed in an array to create one large light emitting surface (LES). I imagine they are fairly bright.

I've ordered a couple of the Cree CXA2520 which have a 19mm diameter LES to see how they perform.

It looks like these COB LEDs are connected mostly in series and maybe in some are in parallel. This Cree COB LED needs about 35V to operate as with series LEDs the ON voltages add up. On my boards I stack 3 white or 4 red/amber LEDs to drop about 8V. With 35V ON voltage these COB LEDs would need a dc-dc converter to produce 35V from the 12V battery.

Another item is the wide viewing angle of the COB LED shown below. These COB's look like they're tailored for flood lights or would require a lens to focus the light into a tighter beam. Notice the bottom spatial distribution of the C503B LEDs that I use and how tight their distribution is. The COBs if used as DRL and are bright might cause excessive glare to oncoming vehicles.



Cree CXA2520



Cree C503B-WAN

[PabloX]

Originally Posted by spoke

Until you mentioned COB LEDs, I had not seen them. Did some searching on Digikey and they have a wide assortment available.

The big advantage I see is that they come in long rectangles and I think, visually, they'd be great as a DRL. You'd see a continuous, large area of light being emitted. Good point about glare though.

https://www.dhgate.com/product/60x8mm-1w-3w-cob-led-light-source-dc-3v-4v/402787684.html

https://store.ijdmtoy.com/High-Power-COB-LED-Bulbs-For-Car-s/288.htm

I have your LED DRL/signal boards in front and they work well, but I'd kind of like the DRL portion to be brighter.

Hopefully these work for you.

[Satanas]

Originally Posted by spoke

Very nice work adapting the LED bulb to the front turnsignal bucket. The perfect positioning allows the top, bottom, and side LEDs (by your orientation) to reflect light towards the front as the reflection of the LEDs is visible in the picture.

My only suggestion if you happen to change your setup or others want to follow your installation is to remove the ballast resistor and change the OEM flasher to LED-compatible EP26 which is readily available online and in some auto parts stores.

Thanks for your suggestion Spoke.
As you can see, my adaptation is a simple and cheap solution made from a complete kit made in China which includes this ballast resistor. I guess the advantage is to keep the standard bulb on the back, and be able to use the LED bulb on the front with the OEM flasher.
I'll see if this solution is reliable...
My goal was to make no modification to the car and be able to come back quickly to the original turn signal on the front without any problem.

[spoke]

I was asked how well amber LEDs would shine through a red lens and if they would look amber or red. The amber LEDs show through the red lens and they do look amber.

Setup is a board with 56 amber LEDs and the red lens is from my 930. Light intensity is measured at 1 meter straight with the LEDs and then behind the red lens.

Amber LEDs only: 209 lux
Amber LEDs behind red lens: 60 lux

To compare the loss with red LEDs behind a red lens, the same test was repeated for 56 red LEDs.

Red LEDs only: 210 lux
Red LEDs behind red lens: 146 lux

It looks like the loss of the amber LED through a red lens is about 2x the red LEDs. Since the LEDs are 2-3x brighter than standard bulbs, it would seem the amber LEDs behind a red lens are about as bright as a standard bulb.