Help with High Power LED Driver circuit for Vehicles

Discussion in 'The Projects Forum' started by dhyaks, Aug 13, 2014.

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  1. dhyaks

    Thread Starter New Member

    Jun 19, 2014
    I'm Dhyaksa from Indonesia,
    Last week i get some High power LED (XML-T6 Series) emitter from my friend and i want to make some LED Driver circuit for these High Power LED.
    Specs :
    ~3.7 - 4.2V
    3A Max. Current

    I still confusing about PWM circuit and because of limited component to make D.I.Y LED driver, i decide to make the driver from Adjustable regulator and Power transistor, (Attachment added)(sorry for my bad drawing from corel).


    But the problem is : when i adjusting the regulator circuit without any load (LED) it can show 3,7V or 11,2V (for 3 Leds in series). but when i connected to load, voltage just drop too much and the current just show on 0.26A only, can anybody give me a suggestion for my project?
    The Source is from VLRA Battery specs 12V / 10A.

    or anybody can give a better circuit suggestion for efficient and durable High Power LED Driver.
    Many thanks.

  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
    Your circuit is more like a constant-voltage power supply; to drive leds, you should use a constant-current circuit. I will be surprised if you didn't ruin the LEDs.

    Read this Instructable. Come back if you have questions..
    Last edited: Aug 13, 2014
  3. dhyaks

    Thread Starter New Member

    Jun 19, 2014
    thank you for correcting my circuit, so i just make a constant current circuit to drive the High power led right? how about the diagram? i mean the constant current circuit is connected series with the led? like :
    Power Source ---> Constant Current Circuit ---> LED ---> Ground.

    and do you have any suggestion schematic either? i can't fully understand about these site you have been shown :confused:

    thanks MikeML.
  4. bertus


    Apr 5, 2008

    I am closing this thread as it violates AAC policy and/or safety issues.

    6. Restricted topics.

    The following topics are regularly raised however are considered “off-topic” at all times and will results in Your thread being closed without question:

    • Any kind of over-unity devices and systems
    • Automotive modifications
    • Devices designed to electrocute or shock another person
    • LEDs to mains
    • Phone jammers
    • Rail guns and high-energy projectile devices
    • Transformer-less power supplies
    This comes from our Tos:
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    There will be enough sites where automotive questions can be discussed :
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