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problem with led G4 bulb replacement (LED)

  • 11-11-2015 09:15PM
    #1
    theboyhurley
    Registered Users, Registered Users 2 Posts: 20 ✭


    I have a strange problem with some G4 LED bulbs that I bought to replace some halogen ones in some under cabinet lights in the kitchen.

    The light fixtures use 3 halogen G4 bulbs which are rated at max 20w (12v).

    I purchased some 2w G4 LED lights on ebay.

    The replacement bulbs will not work in on their own.
    They do flash for a moment when switched on but then they go off, and then they retain a very faint glow.

    The curious part is that if I leave one of the halogen bulbs in, with 2 or less LEDs then the LEDs will work.
    I've tried changing the polarity etc but they will act the same.

    This behaviour is the same if 1 use 1,2 or 3 LEDS in the strip. Once I put back on one halogen bulb the whole strip works again.

    Any ideas?
    Tagged:


Comments

  • #2
    Bruthal
    Closed Accounts Posts: 13,370 ✭✭✭✭Bruthal


    The transformers for supplying the 12v probably need a minimum load. The leds are too small a load.


  • #3
    bitethebullet
    Registered Users, Registered Users 2 Posts: 175 ✭✭bitethebullet


    Bruthal wrote: »
    The transformers for supplying the 12v probably need a minimum load. The leds are too small a load.[/QUOTE

    Had the same issue


  • #4
    theboyhurley
    Registered Users, Registered Users 2 Posts: 20 ✭theboyhurley


    Had the same issue

    What did you do to resolve?

    I mentioned this briefly to someone else and I was told that this is solvable by adding a resistor.
    I looked up various sites to try and work out what level of resistor I need.
    I'm not sure I'm even representing the inputs properly, plus I have 3 leds in series.

    Anyway here are the details from my transformer.. should any be able to work it out:

    pri: 220-240v 50/60Hz 0.25A
    sec: 12V eff, 20-60A 5A
    cos=0.98

    My new leds are 12V 2W each (3 of)

    thanks


  • #5
    bitethebullet
    Registered Users, Registered Users 2 Posts: 175 ✭✭bitethebullet


    Mine was a hall light. Smae craic 12V xformer. 5 lights on it. When i replaced the 5 with led's same story as you so i was left 1 of the old bulbs in and the rest led and it was fine.


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