Constructing Halogen LED driver

Discussion in 'The Projects Forum' started by Malimujo, Jun 28, 2013.

  1. Malimujo

    Thread Starter New Member

    May 26, 2013
    8
    0
    I was looking to make cheap led driver for my room lighting And i bought a halogen transformer ( http://www.ebay.com/itm/350771079797?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 ) And 2 10w led ( http://www.ebay.com/itm/130900864879?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649 ).
    So i have some scrap electronich home and i tried to make ac to dc converter and voltage regulator. The output of the transformer is 14-17V depending on the load and i conected it to a normal rectifier KBJ-6j put nice 2200uF capacitor x2 in paralel and ofc rectifier, connected everything and it worked as a strobe... Saw a video on youtube were they put the transformer on a osciloscope and it seams the frequency is extreamly large 50-100Khz so i tried to make a rectifier out of shocker SB160 diodes and still when i turn it on it works ok for 3-5 sec then it starts acting like a extreamly high frequency strobe and as it continues to work the frequency of the blinking decrises.

    Does anyone have a idea what to do ?

    Ps. Saw this scheme as how to use switchmode rectifiers http://www.dicks-website.eu/transformatortest/schema2.jpg But i have only 2 outputs from the secondary
     
    Last edited: Jun 28, 2013
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,769
    969
    Sure... just buy a proper "constant current" power supply (LED Driver) that is capable of only 1A @26Volts or more (700ma is better as I never like to run cheap LED's or any led for that matter at their max rating)
    Hook the 2 LED's in series and done. Of course you will need to use heatsinks for the LED's.. They will quickly burn up without one.

    But LED's MUST be fed from a current limiting circuit as they cannot regulate their own. They are NOT a resistive lightbulb. They are diodes.
     
  3. Malimujo

    Thread Starter New Member

    May 26, 2013
    8
    0
    Yes i know led drivers arre good but they are prety expensive and i made it so the exit of the transformer goes thro 2 rectifiers made out of shocky diodes and then each has a further circuit comprising of a 2200 uF 25 v cap and a LM317 as voltage regulator with improved riple filtration (10 uF cap from R2 to -) and only then to the led on a large heatsink from an old procesor. But i wana know why does it still have riples and how to fix it
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,769
    969
    why not post a schematic so we don't have to guess what you did.
     
  5. Malimujo

    Thread Starter New Member

    May 26, 2013
    8
    0
  6. DickCappels

    Moderator

    Aug 21, 2008
    2,651
    632
  7. Malimujo

    Thread Starter New Member

    May 26, 2013
    8
    0
    Vorked for 30 ish sec normal then again like strobe seams the transistors in the powert surply are overheating :(
     
Loading...