Trying to adapt LED's

Discussion in 'The Projects Forum' started by Gulliver55, Nov 11, 2009.

  1. Gulliver55

    Thread Starter New Member

    Apr 5, 2009
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    I have seen several people converting their bulb turn signals to use LED's.
    One person in particular took the housing of the turn signal apart and retro
    fit it with 80 LED's that blink in sequence.

    I would like to do the same. The LED's are arranged in 4 horizontal rows
    that are 20 LED long separated by the space of a single LED. He used
    something he called Lumiled Stud LED's.

    Any help will be greatly appreciated.
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
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    The hardest part is the physical mounting and connections of the LED's

    For sequencing, see Bill Mardsen's Blog for all sorts of circuits to drive them, flash them, and other stuff.
     
  3. Gulliver55

    Thread Starter New Member

    Apr 5, 2009
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    I am reading through his blog now, thank you for the link, and a lot of what he
    writes sees to be written for a reader with far greater circuit knowledge that I posses.

    I must admit, I am not all that proficient with electronics but I can follow direction
    real well! :) I Googled the symbols he used so I know what each component is and
    I then Googled those to learn what their function is.

    I was reading the manufacturer brief on the LM317 when I read something I didn't
    understand.

    " Normally, no capacitors are needed unless the device is situated more than 6 inches from the input filter capacitors in which case an input bypass is needed. An optional output capacitor can be added to improve transient response. The adjustment terminal can be bypassed to achieve very high ripple rejection ratios which are difficult to achieve with standard 3-terminal regulators."

    If I understand the principle, my circuit will need the LM317, or something very much
    like it so that voltage is maintained since the AC current generated by the alternator
    will vary between battery voltage and a charging voltage. Could I use LED's with
    an operating range of 9-14.7v to simplify the circuit design?
     
  4. Wendy

    Moderator

    Mar 24, 2008
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    The LM317 can be configured as a current regulator (which needs no capacitors) or as a voltage regulator (which does). Basically both have their uses for LEDs.

    If you start off drawing what you want (or think you want) and ask questions you will get lots of help here, from myself and others. I wrote the article to start people off, and get the questions flowing.
     
  5. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    AND getting your dashboard sensor to work properly (if you have one).

    I understand some sensors are very sensitive to changes in resistance. So much so that if you replace with a off the shelf bulb, the sensor may report a false light out.
     
  6. Gulliver55

    Thread Starter New Member

    Apr 5, 2009
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    0
    I will make a (rudimentary) drawing of what I want but I suspect what
    you meant by drawing is something more along the lines of what you posted in your blog. That type of drawing is beyond my skill set. My drawing is going to be a layman's drawing and likely to be missing something an experienced person would know I need.

    I believe this issue I have resolved already. I replaced the incandescent
    bulbs located in the front with LED plug in types and added "load resistors"
    so the blink rate is normal and to not trip any bulb out messages. So far, they are working and no issues to date.
     
  7. Wendy

    Moderator

    Mar 24, 2008
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  8. gerty

    AAC Fanatic!

    Aug 30, 2007
    1,153
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    One of my students changed to leds, and the problem he ran into was water getting into the the connections. It took about 3 -4 months for the problem to show up.He repaired the corroded connections and sprayed it with some kind of "liquid rubber" and it cured his problems.
    I thought he got the spray at Harbor Freight but all I could find there was a brush on type.
    http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=36821

    Whatever you decide, make sure water can't get to it.
     
  9. Gulliver55

    Thread Starter New Member

    Apr 5, 2009
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    0
    Reading it now...this seems to be very close to what I want only
    he wanted the LED's to remain on. That would seem to override being sequential?
    Unless he meant the circuit would be on and continuing to power the LED's in
    the proper sequence.
     
  10. Wendy

    Moderator

    Mar 24, 2008
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    He wanted a ripple, then when the flasher turned off they all turned off. Just thought you'd like the read.
     
  11. yfx4

    New Member

    Sep 30, 2009
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    I've built several sets of truck tail lights with LEDs. I made PCB's that fit into the lamp bucket after I pulled off the lens. The lens was resealed. The OEM water seals are still intact on the backside. One set of tails has 372 LEDs total. The owner has the lenses tinted so they match his black truck--you could barely see incandescent bulbs through them. The LEDs are just a bit brighter than stock though the lenses are DARK. Load resistors may be needed on the brake side too for the cruise control to work (my 2004 F150 needs this).
     
  12. Audioguru

    New Member

    Dec 20, 2007
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    In Canada it is illegal to modify lighting on a motor vehicle unless the new lights are certified. But there are millions of uncertified Chinese ones being sold.

    They are too dim and have a viewing angle too narrow.

    There are thousands of little kids running around unseen at night in their little "ricers" that have these cheap lights.
     
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