I am considering designing something for the rear lights in my Z. I am wanting to convert them to LED. All of the LED conversions I've seen just don't look that special on the Z32, whilst they look better than stock, when illuminated, the LEDs are very defined and I've never seen anyone make them illuminate the complete area the bulbs did. The nice radius of the edges is lost and I want a more even glow.

 

I am wondering if anyone here would know whether a contoured PCB with wave soldered micro/nano LEDs would work effectively? You'll not only get rid of the dots that large standard size LEDs emit but also, being more compact, you'd also be able to match the radius of the edges.

 

I don't know much about micro LED technology, so any input would be great.

 

I am concerned about being able to create a 2 stage system like the rear lights/brake light. Not sure on the boundaries on micro-LEDs and wiring.

 

In effect, I want to create 2 thin PCBs with wave soldered LEDs that can simply be placed behind the defusers in the rear lights.

 

Not sure how do-able this would be.

 

Edited September 9, 200817 yr by FunkySi

Similar to the right hand picture.

 

 

....this sort of thing, but high powered with curvatures that match the Z32 light bezels.

 

....no-one suggest clear-corners as it's those that I don't want to replicate.... lol

I think the propper name for them are 'miniature SMD LEDs', they are tiny. About 2mm x 2mm They have been in cell phones for some time now.

 

Hi Si

Probably not the answer to your question, but my thoughts on the subject.

 

The smd leds(or micro leds) are cheap as chips but cannot be soldered with a normal iron and with out magnification as the terminals are tiny. There is a soldering system available to them but i havent had the time to source properly.

Wave soldering would be fine if you could find a company to do them, they are generally set up for mass production of specifics, although there must be some small electonics firms around to offer this service.

 

I tried something similar in converting one of the reversing lights to fog using leds on a pcb board, my findings as follows: you need the pcb an inch or so away from the lense, otherwise you see the dots of light and with the way the back moulding of the light housing is you cant do it without cutting away most of the plastic to get the distance.

You would also need to cut away the plastic moulding to get the depth to be able to cover the complete contour of the lense.

 

Wiring the reds as a 2 stage is straight forward, getting it to look right, which is what you are after is the pain imo. And you would need hundreds of leds to do the job

 

The smd leds are the same forward voltage just in micro size, i bought some blue ones, they come taped to a strip and are so small that i decided not to bother using them until i had the right system to solder them.

 

It will be good to see any suggestions or progress on this.

 

Cheers

Graham

Thanks Graham. Fortunately, I supply PCB hardware to electronics companies, and I could probably get some specials made as my colleagues have a wealth of good contacts if I really wanted to go that route.

 

I've not taken apart the rear lenses, so can't quite understand why I'd need to cut anything forward of the diffuser, I' need to get a spare set to pull apart! LOL...also, shouldn't the stock diffuser be sufficient to evenly spread out the light of densely populated SMD LEDs?

 

Regarding the side light/brakelight issue, can you not get SMD LEDS with dual functions in them to save on space so that you could still populate the PCB enough to give the desired light emission? Is that the same as dual stage?

....also, what are the restraints with getting the look of dual stage LEDs? BMW and Mercedes managed to get it work with regular sized LEDs. No additional population within the lense.

....here are the ones I'm interested in.

 

Si why are you bothering with all this! We all know you want to give in and install some lambo style round lights :D :rofl: :rofl: It just so happens i'm selling my old ones ;) :D

Hi Si

Re: dispersion, the bulb utilises the reflector at the rear of the light to help project the light evenly across the lense. If you place the pcb board directly behind the diffuser, you have to rely upon the leds doing the work, so if they are too close to the diffuser, you will see the dots, so by drawing them back away from the diffuser you will see amore even light.

 

By using a 33watt resistor in line with the side lights and the break light feed direct to the leds with no extra resistor, you will get the correct effect of sidelight/breaklight without the need to over populate the board with extra leds.

 

Cheers

Graham

Si why are you bothering with all this! We all know you want to give in and install some lambo style round lights :D :rofl: :rofl: It just so happens i'm selling my old ones ;) :D

 

I'd rather smear faeces all over my interior! lol

 

 

 

Hi Si

Re: dispersion, the bulb utilises the reflector at the rear of the light to help project the light evenly across the lense. If you place the pcb board directly behind the diffuser, you have to rely upon the leds doing the work, so if they are too close to the diffuser, you will see the dots, so by drawing them back away from the diffuser you will see amore even light.

 

By using a 33watt resistor in line with the side lights and the break light feed direct to the leds with no extra resistor, you will get the correct effect of sidelight/breaklight without the need to over populate the board with extra leds.

 

Cheers

Graham

 

Oh right I see. I guess by gutting the tail lights, you'd remove the rear reflector and something like that, it would give the appearance of having darker/dulled lenses. Unless there was some chrome effect film that I could cover the array with?....if that makes sense.

 

Regarding the resistor, does that mean you can't populate the board as densely as you could without them?

You can have as many leds as you want as they will have their own resistors either in series or parallel, the 33watt resistor is a separate item and is connected inline from the feed to the sidelights which dims them to the right brightness for sidelights and the brake light feed without a resistor connects to the same live feed to the leds, so in short 2 feeds to the leds, 1 with the resistor and the brake light feed without.

Oh right I see, so you can have one circut in series? Rather than 2 seperate circuits?

Ignore what I just wrote...lol

So, it's doable then. Main contraints are 'getting someone to fabricate it', which I should be able to do. Then there's fitting it in the stock light surrounds. If it can be fitted behind the stock defuser with sufficient space. Also, main constraint for me, would the lights appear duller without the stock innerds behind the deffuser? How can that be overcome?

In a way, lets say for instance you have 50 leds on your pcb, they should have the 12v/470 ohm resistors on the board so that all 50 leds light up. Now forget the 470 ohm part, thats just an example and depends on how they are wired. The 33watt resistor inline with the sidelight feed will light up all 50 leds. The 33 watt resistor acts as a choke to stop the full brightness for sidelight use. By connecting the brake light feed to the leds after the 33 watt resistor all 50 leds will light up at full brightness. thus giving you the 2 stage effect you are after.

I have done this to my rear leds (6 pot venoms) and works perfectly.

 

You will also need a separate resistor for the indicator leds so they flash correctly and you will need to take out the light out bulb in the dash.

The lights wont appear duller than stock, the problem is with even distribution through the diffuser that the reflector helps the bulb to do, brightness wont be an issue, not seeing the dots of the source is the issue to overcome

Oh right, I understand completely. So I wouldn't be able to have the indicator check light in the dash?

 

Did you get the desired brightness level with that method you used when doing your lights? Do you have a video clip?

The lights wont appear duller than stock, the problem is with even distribution through the diffuser that the reflector helps the bulb to do, brightness wont be an issue

 

 

If you have very densly populated PCBs with very small micro LEDs, spaced far enough behind the diffuser, should the light distribution be an issue?

The ecu thinks that bulbs have blown because of the lack of resistance. The dash warning light would come on when you touch the brakes or when the lights are on.

 

I have found that using this method, which by the way isnt my own method, its suggested when i bought the rear leds works really well.

I dont have any vid yet, but they are the same as mario's, i have some pics, but i will try to get some video later.

Oh right, yes of course. Is there a way of overcoming that bit fitting additional resistors to fool the ECU to think otherwise?

 

Will the indicator flash really quickly as if a bulb has blown?

anything is possible, i just need to work out the resistence of the rear light load total and work out the resistor to mimic it.

There is a resistor to stop the indicators flashing too fast, so thats do able

Oh right cool. I'll have a chat with a few guys at work over the course of the week and see if there's anyone I could use. I also need to get a set of spare clustors and rip them apart.

 

One last thing. When fitting an LED array in the rear lense, you loose the chrome reflector, if it's possible, would the LEDs be bright enough to penetrate chrome coated film? Visually, without the lights working, I want them to look as near-stock as possible. Don't want any dulling/darkening of the appearance of the lense.

If you have very densly populated PCBs with very small micro LEDs, spaced far enough behind the diffuser, should the light distribution be an issue?

 

not at all, but thats where the possible cutting out of the rear light moulding comes in, if you cant get the board far enough away from the diffuser.

I found that with the reverse light lense at least that the moulded part of the bulb holder as it bowls out ends up only a few millimetres away from the lense

making placing the board onto the complete contour of the lense not possible without losing some plastic. This may not be the case with the rear lights, i will take apart a spare pair i have here to see whats possible.

 

 

And off topic, by the way i did some pods for transmandan in white and i have to say they looked pretty cool, more of an updated stock look but crisper.

I get what you mean, it will be a case of trial and error on that one, possibly a frost filter lighting gel, i used some for the auto selector so that you couldnt see a point of source.

That's cool. It's something I still want doing. I fitted LEDs to a V6 converted Astra I built about 6 years ago and loved the look. Makes it much more crips and modern. Need to get a set of UK clocks though really before I do that.