led questions

Discussion in 'The Projects Forum' started by racerd146, Apr 19, 2009.

  1. racerd146

    Thread Starter New Member

    Apr 19, 2009
    2
    0
    im planning out making a custom led tail light with 3 - 5 different circuits low brake, high brake and 2 turn circuts, when i used www.ledcalc.com i played with the voltages cus they can bounce around im not sure what resistors to use cus they vary from 56 ohms to 180 ohms i was thinking of using 4 pin RBG leds but not sure how to control them to flash red amber and white

    and i have seen led tail light replacement bulbs that one led lights up in a circle but i cant seem to find a schematic to make one

    thanks in advance for all your help
     
    Last edited: Apr 19, 2009
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Well, it's normally called parking or running lights, brake lights, and turn signals. The parking/running lights are about half as bright as the brake and turn signal lights. The allowed colors are quite specific, depending upon where you live.

    In the USA, parking lights and brake lights must be a red-orange, around 630nm in wavelength. Turn signals are either the same red-orange or an amber color; I don't know that wavelength offhand. The standards are established by the Department of Transportation. If you use colors that are not within the DOT specifications, you will likely find yourself getting rather expensive tickets.

    Plan on your electrical system being around 14v while the engine is running.

    Use resistors to keep the current in line with the typical Vf @ current specification. The different intensity between parking/running lights and brake/turn signal lights can be performed by PWM.

    Pure red is not a legal color to use for brake/taillights in the USA. It needs to be red-orange.
    White is only legal for back-up lights.

    Your project would be much less expensive if you just stuck with legal and reliable red-orange LEDs like Phillips Superflux HPWT-RD00 (44°x88°) or HPWT-MD00 (100°) 70mA units.
    That effect is probably a result of an aftermarket replacement lens.
     
  3. racerd146

    Thread Starter New Member

    Apr 19, 2009
    2
    0
    i want these BRIGHT as i legally can get them cus here in orlando drivers suck so i want to blast my brake lights at them, i was thinking making the brake lights flash like i have seen a million bikes do when they hit there brakes, so witch led can i use?
     
  4. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    If they are too bright, too dim or the wrong color, you will have problems with expensive tickets.

    I already gave you a couple of specific recommendations; the former are preferable.

    I live on the east side of town, and I'm fully aware of the traffic situation.
     
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