Pics of new style LED taillight and turn signals

[mohrds]

Originally Posted by ThetaReactor

Ultra spiffy.

Incidentally, what is the output of those LEDs? I'm guessing they look a bit more red in person, too...

They are pure red. It is virtually impossible for an amatur photogropher to get a color correct picture of an LED.
Brake lights:
4-PIN Super Flux Red Lamp: 5,000 mcd
7.4mm x 7.4mm water clear package. High performance super flux led lamps, suitable for high pulse operation of up to 50mA. Unique conical radiaton pattern, wide surface area distribution. Ideal for backlighting outdoor signs, moving message boards, displays. Color: InGaAlP/GaP TS Red (630nm). Intensity: 5 cd (If=20mA). Total angle: 70 Deg.

Turn Signals:
4-PIN Super Flux Amber LED Lamp: 3,500 mcd
7.4mm x 7.4mm water clear package. High performance led lamps, suitable for high pulse operation of up to 50mA. Unique conical radiaton pattern, wide surface area distribution. Ideal for backlighting outdoor signs, moving message boards, displays. Color: InGaAlP/GaP TS amber (590nm). Intensity: 3.5 cd (If=20mA). Total angle: 70 Deg.

CMHSL:
Super Bright Red (60 Deg.): 3,000 mcd
T1 3/4 High flux LED lamps utilizing InGaAlP/GaP technology. Color: 630 nm TS red. Viewing angles: 60 Degrees. Water Clear lens. Solder leads without stand-off.

[mohrds]

Originally Posted by SilverSpear

hehe, i am waiting. I want it, I want it, I want it, I want it, I want it................................................ .... oh boy

I can do the board over here very easily, i have some friends who work in electricity and stuff and they have a machine to do that board. still i need the leds, Doug: I need each of the parts specs and if you can send close pics of them for me what to look for...

Xcellent job buddy..

You can get all the specs and images at lc-led.com The individual part numbers are in the parts list attached to my first post.

I'd love to get your freinds to do a batch run of boards. The design is in ExpressPCB format http://www.expresspcb.com but I could re-create it in autocad or something if they need it in that format.

Doug

[SilverSpear]

just an idea guys, i think you have junk yards in the states, right? and you do have damaged cars with led taillights, right?... so why don't someone go and get a bundle of broken led taillights and do the conversion without taking that expensive road...

[AFBeefcake]

Originally Posted by mohrds

Yes, but it required building a custom flasher. I wasn't about to drop $40 for a "LED Flasher" when I can build one for less than $5.

How would one build one?

[SSSVX]

LED lights are much brighter and faster for my observations.

It looks awesome, doug!

When I'm rich, I will consider about this improvement...

[mohrds]

Originally Posted by SilverSpear

just an idea guys, i think you have junk yards in the states, right? and you do have damaged cars with led taillights, right?... so why don't someone go and get a bundle of broken led taillights and do the conversion without taking that expensive road...

Two reasons:
1. Salvage yards charge top dollar for taillights with LEDs in them
2. The LEDs and circuits are coated with a clear epoxy about 3mm thick to provide shock resistence. That stuff is virtually impossible to remove without destroying the components.

[mohrds]

Originally Posted by AFBeefcake

How would one build one?

I'll dig up the schematic and post it.

"Seriously, I can't imagine anyone on this board shelling out $500-600 for this conversion."

*cough* I would.........

BG Micro has some excellent deals on LEDs, by the way...

http://www.bgmicro.com/pdf/page11.pdf

And I'm sure you've come across these monsters:

http://www.luxeonstar.com/

A friend of mine put in a blue one as the dome light on his Jetta. It was not something you wished to turn on without warning.

[kuoh]

Great job on the build, but you can get almost identical LEDs at Digikey for about 1/2 the price and I'm not sure that you really need those extra diodes or the large power resistors. The single current limiting resistor for each 3 LED array should suffice I would think.

160-1625-ND 3375mcd $30.80/100 pcs (red slightly dimmer)
160-1631-ND 7500mcd $33.80/100 pcs (red much brighter)
160-1658-ND 3200mcd $27.60/100 pcs (red same)
160-1632-ND 4180mcd $33.80/100 pcs (amber same)

KuoH

[mohrds]

Originally Posted by kuoh

Great job on the build, but you can get almost identical LEDs at Digikey for about 1/2 the price and I'm not sure that you really need those extra diodes or the large power resistors. The single current limiting resistor for each 3 LED array should suffice I would think.

160-1625-ND 3375mcd $30.80/100 pcs (red slightly dimmer)
160-1631-ND 7500mcd $33.80/100 pcs (red much brighter)
160-1658-ND 3200mcd $27.60/100 pcs (red same)
160-1632-ND 4180mcd $33.80/100 pcs (amber same)

KuoH

Great find!

The diodes are for keeping the tail/stop circuits isolated. I needed two for each circuit to keep the board layout as simple as possible. I went with those resistors because they were the same price as the smaller ones.

To keep the panel thin and pleasant looking, all the resistors/ diodes are on the back, only the LEDs are on the front side.

Please, I'm looking for any improvement ideas so keep 'em coming!

Doug

[kuoh]

Ok, I see where I went wrong now. You're using the larger resistor to limit the brightness for the taillights and the brake lights bypasses it. Did you intentionally leave out the tail light resistor for the lower 3 rows of lights on the circuit board PDF?

Looking over the parts list, it appears that you've designed the LED current to be about 72ma@12.7V when the brake lights are activated. The spec sheet indicates the maximum forward DC current is 50ma and pulse current is 100ma. Since I see no PWM circuitry, I would suggest going up on the array resistors to dial the current down to below 50ma. 120 ohm resistors should work fine.

KuoH

Originally Posted by mohrds

The diodes are for keeping the tail/stop circuits isolated. I needed two for each circuit to keep the board layout as simple as possible. I went with those resistors because they were the same price as the smaller ones.

[mohrds]

Originally Posted by kuoh

Ok, I see where I went wrong now. You're using the larger resistor to limit the brightness for the taillights and the brake lights bypasses it. Did you intentionally leave out the tail light resistor for the lower 3 rows of lights on the circuit board PDF?

Looking over the parts list, it appears that you've designed the LED current to be about 72ma@12.7V when the brake lights are activated. The spec sheet indicates the maximum forward DC current is 50ma and pulse current is 100ma. Since I see no PWM circuitry, I would suggest going up on the array resistors to dial the current down to below 50ma. 120 ohm resistors should work fine.

KuoH

I probably missed it (or got distracted) when creating the circuit.

I used this site http://ourworld.compuserve.com/homep...Bowden/led.htm
and the specs from lc-led's website to find the resistors. It calculated 75 Ohm at 13 volts will give me 50mA. If it is wrong, then I'm probably in trouble

[kuoh]

What values did you put into the form? With 3 LEDs at 2.2V each running 50ma on 13V system voltage, it comes up with 130 ohms. However, that form does not take into account the extra 0.7V dropped by the isolating diode.

The way to calculate the value of the current limiting resistor is to subtract the LED voltage(s) from system voltage, then divide by the desired LED current. With the values you're using now, you're exceeding maximum DC current by almost 50%, which will probably result in the LEDs failing much sooner than expected. It may be the reason that you already have one dead column, one of the LEDs might have already fried.

KuoH

[mohrds]

Originally Posted by kuoh

What values did you put into the form? With 3 LEDs at 2.2V each running 50ma on 13V system voltage, it comes up with 130 ohms. However, that form does not take into account the extra 0.7V dropped by the isolating diode.

The way to calculate the value of the current limiting resistor is to subtract the LED voltage(s) from system voltage, then divide by the desired LED current. With the values you're using now, you're exceeding maximum DC current by almost 50%, which will probably result in the LEDs failing much sooner than expected. It may be the reason that you already have one dead column, one of the LEDs might have already fried.

KuoH

I did for the low end 2.2V each and 10.2 volts gives me 75 Ohm, on the max end, 3.1V and 13.2 Volts gives me 75 Ohm, so I should be good with voltages between 10.2 and 13.2

The "dead" leds aren't dead. If you tap them, they come back on. They just have bad solder joints somewhere.