Elite Flashlights - The Best LED Flashlights, Chargers and Batteries
Results 1 to 9 of 9

Thread: 7135 Circuit Problem

  1. #1

    Default 7135 Circuit Problem

    I'm trying to use a AMC7135 powered by 4S lifepo4 to drive an XML EasyWhite 12v led but it isn't working. Less than 1ma is going to the led.

  2. #2

    Default Re: 7135 Circuit Problem

    amc 7135s have a maximum voltage input of 6 volts. unless you have something to deal with this (such as 3 amcs in SERIES) then i'd expect the AMC is dead.

  3. #3
    Flashaholic* AnAppleSnail's Avatar
    Join Date
    Aug 2009
    Location
    South Hill, VA
    Posts
    3,819

    Default Re: 7135 Circuit Problem

    Quote Originally Posted by Hmmm View Post
    I'm trying to use a AMC7135 powered by 4S lifepo4 to drive an XML EasyWhite 12v led but it isn't working. Less than 1ma is going to the led.
    Connect the DriverOut to an appropriate resistor... say, (V=IR, 12v = 1A * R, 12 ohm 12 watt) and see what happens to check the driver.
    Connect the LifePO4 to the XML EasyWhite with a decent resistor to check the batteries, LED, and voltage.
    My biggest light-hog is my camera.

  4. #4
    Flashaholic* bshanahan14rulz's Avatar
    Join Date
    Jan 2009
    Location
    Tennessee
    Posts
    2,692

    Default Re: 7135 Circuit Problem

    I bet the amc chips are dead. Find a different driver would be your best option.

  5. #5

    Default Re: 7135 Circuit Problem

    the amc7135 is not dead. it still works powering a "normal" xml off a 18650 battery.the leds are fine. I tested them before with a linear regulator but it needed toomuch voltage overhead. I was hoping to use the 7135 for its low voltage overhead.

  6. #6
    Flashaholic* AnAppleSnail's Avatar
    Join Date
    Aug 2009
    Location
    South Hill, VA
    Posts
    3,819

    Default Re: 7135 Circuit Problem

    Quote Originally Posted by Hmmm View Post
    the amc7135 is not dead. it still works powering a "normal" xml off a 18650 battery.the leds are fine. I tested them before with a linear regulator but it needed toomuch voltage overhead. I was hoping to use the 7135 for its low voltage overhead.
    LiFePO4 OC voltage is only 3.3v freshly charged, giving you 0 to 0.9v headroom. Not quite enough.
    My biggest light-hog is my camera.

  7. #7

    Default Re: 7135 Circuit Problem

    I'v been wonding 2 things:
    1) Are you useing an amc7135 based driver or a bare chip? Do you have any information about it from where you bought it?
    2) What gave you the idea that this would work?

  8. #8

    Default Re: 7135 Circuit Problem

    The led starts turning on around 11.3 volts for me and is running at 1 amp at 11.7 volts. They are bare chips that i etched a board for. I ordered them from ebay.

    I don't know why it woudln't work I guess. I assumed that the 6v limit was due to the v-drop of normal leds, making so if you sed over that it would get to hot with 1v drop i don't think i would have too many problems.
    Last edited by Hmmm; 08-04-2012 at 10:41 PM.

  9. #9
    *Flashaholic* kramer5150's Avatar
    Join Date
    Sep 2005
    Location
    Palo Alto, CA
    Posts
    6,328

    Default Re: 7135 Circuit Problem

    What driver circuit are you using? If its just our standard garden variety 7135 driver board with 7135 chips configured parallel, your 4S cells are exceeding the Vin for the circuit.
    CLICK HERE for my flashlight reviews.
    PAUL KIM... AN INDUSTRY GENIUS

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •