RC car Hooking LEDs in series? +knightrider lights?

Discussion in 'General Electronics Chat' started by stanman11, Nov 24, 2011.

  1. stanman11

    Thread Starter Member

    Nov 23, 2010
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    4
    I gutted out an rc 4x4 and im swaping the electronics and theres an extra power output and I want to use that to hook up 4 LED lights.
    My question is how do I connect LEds in series with out losing power?
    Do I place something in between the LEDS?
     
  2. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Hello Stanman,

    You didn't say what voltage is available, nor what the specifications are of your LEDs.

    We need to know what the typical Vf (forward voltage) is for your LEDs at their rated current.

    We also need to know what voltage is available at your "extra power output".

    If you want a "night rider" type of effect, you will need to buy a couple of ICs and build a circuit.
     
  3. stanman11

    Thread Starter Member

    Nov 23, 2010
    230
    4
    Im not sure what the output is. I dont have a Multi meter here. Left it outside in the rain.

    The LEDS Im not sure either as the were on a different rc car.
    I was going to run a resistor regardless.
    I'm using a 9.6v that runs the motors and electronics.

    they seem to lose brightness being connected in series normally though
     
  4. Wendy

    Moderator

    Mar 24, 2008
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    We also need a schematic of what you are trying to. You can only have 2 blue LEDs per chain with 9.6V, and that is assuming you have the full voltage. LEDs are must have resistors.

    A schematic sure would be nice.
     
  5. stanman11

    Thread Starter Member

    Nov 23, 2010
    230
    4
    All Im trying to do is connect 2 white and 2 red LEDs on an already built circuit board from an rc car
     
  6. Wendy

    Moderator

    Mar 24, 2008
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    White and blue are basically the same kind. Typically they drop 3.6 volts. Are all these LEDs in series together, or just the two?
     
  7. stanman11

    Thread Starter Member

    Nov 23, 2010
    230
    4
    I took the electronics out of a tyco typhoon hovercraft.
    its has a 3 motor hook up.
    1 big motor 2 small motors.
    The big motor runs on its own once power is turned on.
    the other 2 motors only when you work the remote.

    The LEDS will replace motor 1.
     
  8. stanman11

    Thread Starter Member

    Nov 23, 2010
    230
    4
    I cant tell but it looks like this on the original board.

    REAR Lights yellow yellow black blck are the wires and it connects as:::
    yellow to yellow to board:: black to black to board

    FRONT LEDS RED and GREEM
    RED connects nect to the rear yeally.

    ok screw this give me 15 min to gear up and take the board out of its water proffing inhousment



    OK IT DOESNT OPEN
    They seem to connect side by side but not sure if they actually connect together.
    I doubt they connect together.
    there has to be a power amp or mosfet chip in between some where
     
    Last edited: Nov 24, 2011
  9. Wendy

    Moderator

    Mar 24, 2008
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    If you are trying to run them all together you are missing some key information about LEDs. Blue = 3.6V Red = 2.5V (Numbers are approximations)

    3.6V + 3.6 + 2.5V + 2.5V = you get the idea.

    LEDs, 555s, Flashers, and Light Chasers
     
  10. Wendy

    Moderator

    Mar 24, 2008
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    Wait, are you replacing existing LEDs with different colors? LED color affects their dropping voltage.
     
  11. stanman11

    Thread Starter Member

    Nov 23, 2010
    230
    4
    no Im simply switching boards. but instead of 2 channels connecting leds I need to use 1 channel because. The LEDS came off the board im taking out
     
  12. stanman11

    Thread Starter Member

    Nov 23, 2010
    230
    4
    I got everything hooked up and working except for the LEDS But I ran into a problem.

    I had to take the on switch off the board because it was causing clearance issues.
    I soldered and external one on but its not working maybe this will work or not?

    ok it goes from:
    battery +to board
    B - to onbaord switch.

    New switch

    Batter to board
    B- to where the switch was. But the old switch is 3 prong
    So one proing is not hooked up.
    If I connect that extra prong to ground on the board will it work?

    ok that worked im good to go
     
  13. stanman11

    Thread Starter Member

    Nov 23, 2010
    230
    4
  14. Wendy

    Moderator

    Mar 24, 2008
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    Show us the lights, the other you seem to have down.
     
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