Backlit LED HVAC Controls for your B4?

Are you interested in a set to backlight your B4's HVAC controls?


  • Total voters
    13
  • Poll closed .

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
Anyone interested? I received my first prototype boards in the mail today . I made a goof when I had the boards made and don't have a proper groove to allow correct dispersion of light from the LEDs. I'll tweak/dremel the PCBs for testing this and adjust the groove cutouts to compensate. Also, I've not used this LED package before, but it's fairly unique. So much that I have only found it in white. Color temperature is ~5600K white is daylight white.

If you guys want more details please ask. Glamor shot time!





I should note that I only have the ring made from the vent selection. However, this PCB has the same dimensions as the fan speed selection. The tricky board will be for the temperature controls. This prototype is for clearance and brightness and dispersion testing.
 
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Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Looking forward to seeing how well it lights the HVAC controls.

Drives me nuts that I can only see the controls at night if I crank the rheostat all the way up, and then the Instrument cluster is way too bright.

I can solder pretty good - send me a few! :D
 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
The LED package is rated to give about 180 lm @ 120 degree spread at 20 mA of current. I think this is a bit bright so I picked up resistors for about 10 mA to the LEDs. Easy enough to varry these to tweak the base brightness.

I actually put these in for that very reason, Windex. I'll post photos tonight if the results are good :)
 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
Oh, and depending on the boards required to make these, if I can do it in 2 or 3 boards that is, I expect that a small order of ~25 people could bring the PCB costs down to where I can send out a set, i.e. it'll cover all 3 dials, for about $60-65 + a little for shipping. If you want to solder yourself I can take off ~10.

FYI - This is my test LED. Looks like Osram has other colors, but I need to check availability.
Looks like there are other color options
 
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Windex

Top Post Dawg
Joined
Apr 1, 2006
Location
Cambridge
TDI
05 B5V 01E FRF
Heh, for $10 i'd let you do the soldering. :D

If you are thinking $65 for all three, and the brightness is good, I'm in.
 

lisab4

Veteran Member
Joined
Oct 20, 2013
Location
Belgium
TDI
1996 Passat B4 1.9 TDI
Any chance of getting the same green light as the dash and other lighting?
 

tdidieselbobny

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Apr 4, 2005
Location
Stafford,NY (WNY)
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'03 Galactic Blue Jetta TDI, '15 Silk Blue Golf Sportwagen TDI
Do you know if you could get blue ones? Years ago Darkscout did the sunroof switches to blue light(not LED) for the Jetta,which I transferred to the Passat,and look good.I didn't see blue led's in the link you provided.I'd like to see pics of the white ones when you can get a chance before I decide.
 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
As long as the package dimensions are close enough to being the same, any other "reverse gullwing" LED will do. I've not looked into color options yet, but white is the most expensive so it shouldn't be much of a problem.

Aaaaanyhow...

So I mucked the prototype progress a bit. Looks like I misinterpreted the pad dimensions of the LEDs by a fair margin. I'd take a photo if I didn't need to get some sleep right now. However, I can sand off the solder mask and still solder the LEDs in their respective places. I've addressed the problem in the CAD work and I took the liberty of adding a drill into the design to account for the 120˚ spread (2.8 + 2*(1.6mm / sine 30˚) = 9.2 mm) which should help "blotchiness". Also in my rush to order parts I neglected one little letter, "K". I ordered 909K and 698K resistors instead of 909 ohm and 698 ohm. :mad: Dumb :mad: dumb :mad: dumb :mad:. Last time I order parts at 8 am, 4 hours after I should have gone to bed.

Due to the expense of the boards, ~$40 for a set of 3 only able to order in multiples of 3, I'll just get new resistors to fix my itty bitty problem and on Tuesday, I'll measure out the left half of the temp control dial. Good new is that I had no dimensional problems with the original board outline. I'll stop by Radio Shack and/or Frys to see if they have any resistors close enough to spec while I wait for the proper SMD resistors to arrive.

:( :( Sorry for the delay :( :(
 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
So, that design above, already scrapped it. Unfortunately 7 LEDs just doesn't cut it; I was hoping for better dispersion characteristics:
Dimmer all the way down and all of the way up:


So I went back to the drawing board as to the simplest way I can disperse the light. The datasheet actually was a bit of help here. First I decided that I needed 2 LEDs per quarter ring because, well you can see why. Next, I paid attention to how the light was interacting with the PCB. I use the PCB as a perforated filter for dimming the bright center spot:


Next up, I masked out the solder mask (what makes a board colored) of the PCB on the side the light emits so the fiberglass helps with the diffusion but doesn't "hold" the light. There is more unmasked than what this image can show:


FYI - I'm doing this prototyping on my dime, but due to that, I'm making special care before I order 3 boards of which I cannot use or alter to work.
I need to make the left half of the temp controls and I can get that to nicely snug together. Oh, and my target of $60-$65 for a complete replacement is still achievable.
 
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Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
Here is v5 of the PCB. I'm going to print it out to make sure it all matches up to the backside of the HVAC panel, along with it's protrusions, and I'll order up some boards. I'm crossing my fingers :)



 
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Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
So they didn't leave the interior "filter" intact, but I got my next prototypes in. I can put a plastic bead of what not of dab of hot glue in the center if I need to dim the bright spot. I'll test these later tonight after I finish some more time sensitive work. Crappy cell phone pics until then.



 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
So, it's been a while ;). If any of you followed my rebuild thread, then you know why I've been busy. Anyhow, today I assembled the latest PCB I had fabbed a while back. Unfortunately it's lighting was too fragmented as well. Thanks to another user on the forum, I was pointed to a different design that another used. There are points to it that I didn't like but overall it's probably easier to implement.

I'm going to have a look at LEDs again, thus meaning that colors can vary more, and change a few things. I'll have to triple the LED count in the very least, but at the same time, I have a good benchmark for how bright of a chip I need in order to make this so it matches the cluster better. Mine are about 3.5-4 stops (photography) too bright.



 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
EL Panels tend to be fairly dim and I'm one of those people who is annoyed by the buzz caused by the high voltage inverters. I'm just working with the HVAC controls (and I see a couple from them), but thanks for the thought.
 

lisab4

Veteran Member
Joined
Oct 20, 2013
Location
Belgium
TDI
1996 Passat B4 1.9 TDI
Thanks for the update! I've been waiting for one :) I also don't like the EL.
 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
October is a rough month for me. I'm sorry I've not completed this yet, but it is on the docket. Aside from bouncing around on 0900 an 1700 start times at work every week, I've recently developed some back problems. I've not forgotten and will get this done asap.
 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
Not forgot. Mounting LEDs flush with a PCB but in a cutout will be the probable option, though due to various circumstances, this is on the back burner for a spell; along with half of a dozen other things.
 

Digital Corpus

Top Post Dawg
Joined
Mar 14, 2008
Location
Ontario, California
TDI
'97 B4 w/ 236K mi body, 46K mi soul
I saw your initial post and though it works, I'm looking to attempt to do something more complete and drop-in. Thank you for your contribution though.
 
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