89 Turbo LED project

89TurboPC · 09-20-2007, 06:14 PM

Well, many of you are into engine/turbo and other stuff for speed. I'm on other hand are more into electronic related. I bought this car since 1995 and been thru BHG like many of you, but the engine is still consider 99% original other than BHG related fixed. Before this Supra, I also had a 85 that I bought in 92 and sold it in 96.

So there it is. My carPC project is completed (other than software update). It's time for me to play around with LED. First thing is external lighting. Once that complete, I will tackle instrument cluster and other internal lighting.

I plan to finish the project and then posted here, but someone already find out on hidplanet.com so I just post in case someone want to work along. There are more discussion about problem I encountered over at hidplanet: MK3 Supra Turbo LED setup project.

Before anything done, I build the PWM (Pulse Width Modulator) that is used to dim the rear running lights and full brightness when brake is on.
This is the circuit. The drawing is similar to some design you find on the web, but the circuit is design base on information I found on hidplanet LED forum. There are many knowledge people in that forum that put great amount of time contribute to the design of the circuit.

89TurboPC · 09-20-2007, 06:25 PM

From the circuit above, working with expressPCB, this is the result.

Bottom of the PCB and the lazer print out. There are 6 of them. I may have 2 or 3 left when I finish and probably sell it back to those who want. But as of now, nothing is for sale.
I use iron transfer method and Ferric Chloride to etch the board. The paper use is the popular Stapples Photo Paper.
Click on the image for larger photo.

Top or silkscreen of the PWM. The same paper is use for silkscreen.

2 PWMs are finalized. One is 9V and the other is 12V. 9V @ 1A is for the front signal. I opted to have DRL as well which being dim by PWM. 12V @ 2A is for the back running light and brake. Dedicated turn signal will be regulated with stand alone 9V. Why I use 9V for turn signal instead of 12? Well, my meter only read between 10-11V instead of 12+V. 9V regulated will be ok on the safe side

Each of those regulator will power 16 amber LED running at 30mA.

This is what the whole light housing look like. There are 1 tiny screw at the end of the housing (marker end). Use a needle noise plier to unscrew/pull it out. Once the screw come out, you can use oven heat to separate the lens if you wish. 280 degree F for about 5 minutes (make sure to check often). I use hair dryer at low speed and high heat. Come out nice and clean after 4-5 minutes.

The smaller board with 10 LEDs is the amber marker light. Those run at car voltage (12.8V the same voltage as factory 3rd LED brake light). I know the brightness will be different, but what the hell.

Because the PWM will be outside of the cabin, I need a protective case of it in case of rain/car wash and other unknown objects.

I want to thanks a few fellow over at hidplanet especially azdave, CoZZm0_AU, DarkAngel, and many others for the contribution to the design of the PWM.

**shaeff** · 09-20-2007, 06:28 PM

nice work thus far!

-shaeff

89TurboPC · 09-20-2007, 06:35 PM

These shots are taken in the garage. One of the light has reflector on while the other isn't.
The following 2 pictures are with the 500K turn about 1/2 way. I still need to adjust the brightness during the day when it is actually in the car.

The following 2 are at max brightness for turn signal.

89TurboPC · 09-21-2007, 09:58 AM

The turn signal and drl combination isn't working so well as DRL. I remove the PWM and have the turn signal by itself.
I modify the marker (smaller 10 led portion) to function as DRL by wire it to the ignition and marker light separate by diodes. Also I add 4 more led so the board look more fill now.
So the current configuration is marker/drl + signal.

The small side markers also get LED. I also wire it to be use as signal/marker.

side front marker is combined to be marker/signal.

The back of the marker. Ugly but, what the hell.

89TurboPC · 09-21-2007, 10:07 AM

Ok some may ask how do I deal with turbo/hyper flash?
I went to local junk yard and get couple flashers from an early (80-85) BMW 3/5 series. Those flasher make by Hella (like most BMW lighting stuff) that came with an Amtel U643B chip. What special about U643B chip? Bulbs failure feature can be defeated.

To disable bulb failure detection circuit, cut the trace to pin 7 of the chip.

This is the BMW flasher and the stock 89 Supra flasher. They are PIN compartible.

. You can see the part number for both flashers. NOTE: pre 89 Supra use different flasher. Pre 89 use #81980-16010 flasher and 89+ use 81980-12070 flashers are not interchangeable. Basically, all Toyota cars of the same year use the same flasher.

Inside of the 2 flashers. You can tell which one is which.

Close up of the BMW flasher internal and the feature chip.

Can you tell where the trace being cut? Thanks to a sharp utility blade.

The BMW flasher flash a little faster than I want it to. I measure the resistor that control the flash rate that came to about 130K ohms. With a 160K ohm, the rate is perfect for me. I don't have one in hand but a 500K POT in hand so I use a POT instead. Adjustable flasher anyone?

The picture below is the 2 BMW flasher, one with a default resistor (130K) and the modified adjustable flasher.

Anyway, the front end is basically finish.

89TurboPC · 09-21-2007, 10:13 AM

Alright, with the front end is completed, it's time to move to the rear tail light.

There are 2 bulbs for marker and brake light, 1 bulb for backup and one for flash. They all has diffuser inside. Signal has an additional yellow lens insert.

The Supra tail light has a total of 7 screws that hold the lens to the housing in addition to the sticky glue. 6 of them can be easily find because they are just next to the bigger screws. This is how they look like

The 7th screw is on the side. If you look at the Left light, it will be on the upper left and upper right on the Right light. See the picture below. The screw is pointed by the pen. You can easily unscrew this one with a plier.

Because I want to re-use those screw, I take my time to unscrew them. The picture below is the tools I use to flatten the plastic around the screw so I can unscrew them with the plier.

This is how it look after the plastic was removed

This is how I unscrew those screws.

One out, 5 more to go.

After all of the screw removed. Turn on an oven and put on bake at 280 F. When the temperature reach 280F, turn off the oven and put the tail light in there on an aluminum foil on top of a bake pan. Keep the oven door partially open and keep an eye on it. After about 7 minutes, I rotate the light around because the light is TOO big for the oven. Keep it in there for another 3-4 minutes for a total of about 10-11 minutes. Take the light out and put it on a tower (to prevent scratch) face down. Use paint scraper or flat head screw driver and start separate the lens. Do not force it, If it doesn't feel easy, try different spot or put it back in the oven for another 1-2 minutes.
Take me about 5 minutes to separate them and this is what it look like.

Alright, time to work on the board for those leds.

*supraguy@aol* · 09-21-2007, 10:22 AM

Awesome work man- I really like the detail of your reports.

89TurboPC · 09-21-2007, 10:39 AM

Thanks guys.
This is what the rear marker/brake led board will look like. There are 90 of those led running 5 in series with 33ohm resistor which is about 37-40mA thru each led.
I already etch the board and drilling the holes, but couldn't find the freaking reader to upload the pictures.

*Poodles* · 09-21-2007, 10:52 AM

damn, making your own boards any everything... and even silk screening them

very good work