Help picking/identifing LED's for gauge cluster

Discussion in 'The Projects Forum' started by SpeedEuphoria, Nov 7, 2010.

  1. SpeedEuphoria

    Thread Starter Member

    Mar 23, 2008
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    Hello again

    I'm trying to change the color of my stock 03 Dodge Stratus gauge cluster from orange to blue. There are no removable bulbs in this cluster(I wish) they are soldered surface mount LED's.

    I found a "How-TO" on it but not sure what LED's to get. Here is the how to (without signing in you can view the pics by clicking the photobucket links) http://www.2gstratus.org/forums/index.php?showtopic=31352

    Anyway I found some on ebay here: http://cgi.ebay.com/50-Surface-Moun...915?pt=LH_DefaultDomain_0&hash=item20b4e8898b

    I am unsure what led's I would need. The ebay ones are 0805's. I found a page describing a couple other surface mount led's and I'm not sure how to tell them apart other than size.

    Is the only difference size?

    Thanks in advance I know someone will know as I've seen some led projects here
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Blue would be a poor choice.

    Orange is close to what it should be.

    Aircraft use red for instrument lighting. That is because red is the least likely color to cause night blindness; which is a very likely reason why tail/brake lights are a red-orange color.

    However, I'd prefer that a Moderator weigh in on this before continuing discussion on this due to safety concerns.

    In the meantime, please review this thread:
    http://forum.allaboutcircuits.com/showthread.php?t=40361
     
  3. marshallf3

    Well-Known Member

    Jul 26, 2010
    2,358
    201
    Not much of a how to if it doesn't indicate the size.

    Go to a major website like mouser or digikey and look through the surface mount LEDs, click on the datasheets to see dimensions.

    Once you find the dimensions you're going to need to measure the voltage and current of an existing LED while it's operating then try to match things up.

    The problem enters in that blue LEDs take more voltage to operate than orange ones so you'll have to locate and change the current limiting resistor(s) as well.
     
  4. SpeedEuphoria

    Thread Starter Member

    Mar 23, 2008
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    0
    Last edited: Nov 7, 2010
  5. SpeedEuphoria

    Thread Starter Member

    Mar 23, 2008
    11
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    Well got them soldered in, after the 1st one they were not bad to remove(figured out an easy procedure). 1st one was a pain since they are all also glued on the pcb.

    Anyway they are deff dimmer than the orange ones. Pretty sure thats due to the voltage.

    There are 8 resistors that say 220ohm 3w, I'm thinking those may be for the LED's, but there are also more led's on the board for all the warning/turn signal lights. there is also a LCD display on the board for the odometer

    if I posted some decent pics of the board do you think you could point me to the ones you think are for these LED's?
     
  6. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    3,795
    951
    If you can see the resistors on the board, you can trace the copper runs (with your eyes)on the board from the resistors to the LED's. That will tell you which ones they are.
     
  7. SpeedEuphoria

    Thread Starter Member

    Mar 23, 2008
    11
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    Well what's strange to me is that there are 8 identical resistors on the board, all on the same side.

    The other thing is that with the gauge motors out the LED's would not light, so they are tied together but pretty sure its just the ground and other wise the dimmer would affect the gauges.

    So I can see what looks like 2 resistors that go to the furthest LED.

    Well just not good at reading pcb's, have to stare at it for awhile and see if I can figure it out.
     
  8. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
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    Blue LEDs typically need a higher voltage to be on compared to Orange LEDs. If you are using the same resistors for Blue as you were for Orange, the blue will not be as bright due to less current.

    Automotive dimming circuits do not change the resistance in LED based lighting, they typically use PWM for dimming LEDs.
     
  9. SpeedEuphoria

    Thread Starter Member

    Mar 23, 2008
    11
    0
    Even for gauge cluster lighting?

    So what exactly does this mean?? As the LED's can be dimmed/brightened by the dimmer knob(same dimmer that controls the intensity of the HVAC lights which are regular bulbs). Also note that with the dimmer knob unhooked they all dont light up. There still has to be a voltage limiting resistor in the circuit correct? I know pwm would increase the brightness by increasing the duty cycle(only way I know how to explain) but since the orange need less voltage than blue something before the pwm would control the max voltage correct?

    here's some pics:
    You can see the blue marker on the ones of interest(7 in total all controlled by the dimmer)
    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]
     
    Last edited: Nov 17, 2010
  10. Audioguru

    New Member

    Dec 20, 2007
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    I think the Chevy Cruze is Korean. Maybe it was designed by Koreans, not by GM.
    It has a dinky little engine.
     
  11. Wendy

    Moderator

    Mar 24, 2008
    20,766
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    Probably just as well. Wookies comments on night vision are well founded, and not based on myth. Military adheres to it strictly. White and blue tend to reduce night vision (also not a myth) radically, while red and orange maintain it. By reducing the intensity of the blue LEDs you are going to mitigate this somewhat, but it is still a very real and present hazard. One that could have been easily avoided.
     
  12. SpeedEuphoria

    Thread Starter Member

    Mar 23, 2008
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    Like I said that Cruze dash has 2x the intensity of mine currently and I think if you are really concerned about the night blindness(which I do understand the principals) you should write letters to Chevy about how dangerous there new car's dash is. They have sold over 270,000 of them so far and you prob have some in your neighborhood which are blind projectiles. How many people that buy the new cars actually are informed about the risks of having blue instrument lightning? Does Chevy have them sign a waiver saying they are not liable? Are insurance rates higher for cars with blue instrument lighting? Also I'm pretty positive this is not the only automobile/vehicle sold with blue instrument lighting. Better write congress and put a stop to it. While your at it get a bill passed to revoke driver's licenses for people that get in an accident from talking/texting/watching video while driving as surely your going to get hit by one of them 1st.

    Just like everything else I do in life I'll defy the naysayers and figure it out for myself which I have no problems with
     
    Last edited: Nov 18, 2010
  13. Audioguru

    New Member

    Dec 20, 2007
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    The Chevy Cruze is sold in 60 countries in the world for at least one year. Millions of them have been sold. It was The Car of The Year in India maybe last year or the year before. I think it is made and maybe was designed in Korea.
     
  14. Wendy

    Moderator

    Mar 24, 2008
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    I suspect some lawyer will get around to it.
     
  15. mtl

    New Member

    Nov 21, 2010
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    While it is true that red or amber are best for maintaining night vision (makes sense why military would use them), many vehicles come with other colors. The sensitivity of the driver is key (since it's a function of both light wavelength AND intensity) thus the ability to dim the LEDs is a crucial part of a good design. White and blue are certainly the most likely to give people headaches at night, but when dimmed they can be perfectly acceptable as dash lighting.
     
  16. mtl

    New Member

    Nov 21, 2010
    2
    0
    The issue as others have mentioned is that the resistors on your LEDs are correct for the OEM orange LEDs but not for other colors. You're going to need to use a trimming pot to find out what the new resistor value should be (set the pot so that the voltage value is at the typical for your LED of choice......make sure to look at your datasheet for the correct value).

    For instance here's a few common voltage values (min-max):

    Blue (470 nm) = 3.0 - 3.6V
    Green (525 nm) = 2.9 - 3.5V
    Yellow (590 nm) = 2.1 - 2.5V
    Orange (610 nm) = 2.0 - 2.4V
    Red (630 nm) = 1.9 - 2.4V
     
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