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TV interference from LED lamps

Discussion in 'LEDs and Optoelectronics' started by Lionel44, Mar 30, 2016.

  1. Lionel44

    Lionel44

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    Jan 11, 2014
    I have just replaced several MR16 halogen downlights with 12volt ac/dc LED lamps using the original halogen transformers and lamp fittings. Whilst the lamps work perfectly, they cause interference to my tv making it impossible to watch!

    1. Why would these newer type of ac/dc LED lamps cause interference?
    2. Is there a cheap solution or will I have to buy specialist LED drivers?.
    3. If I match the ac/dc LEDs with a LED driver will it still cause interference?.

    I have replaced other halogen downlight lamps with normal LEDs and drivers and had no problems.
     
  2. cjdelphi

    cjdelphi

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    Oct 26, 2011
    Maybe the step down inverter is causing the interference due to a lighter load?

    Attach 1 old halogen bulb in with the LED bulbs see if that helps reduce interference due to a heavier load
     
  3. Lionel44

    Lionel44

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    Jan 11, 2014
    thanks cj. It will take me a while to try that. I will give it a go and let you know, but I still need a long term solution.
     
  4. cjdelphi

    cjdelphi

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    Oct 26, 2011
    Long term solution might be a snubber type circuit, i rarely venture into AC territory :)
     
  5. Lionel44

    Lionel44

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    Jan 11, 2014
    Thanks again.
     
  6. Arouse1973

    Arouse1973 Adam

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    Dec 18, 2013
    You could also try shielded power cables for the Leds power or a small rap around ferite bead for the current power cable.
    Adam
     
  7. Lionel44

    Lionel44

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    Jan 11, 2014
    Thanks Adam,
    are you suggesting shielded cables from, or to the LED TXs?
    By the 'current power cable' do you mean the 240v side?
    There are 4 lamps on each light switch.
    Do you think a better quality shielded antennae cable would help?

    Chinese LEDs at $Aus2.10 each might not be so cheap after all :(
     
  8. Bluejets

    Bluejets

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    Oct 5, 2014
    We get this problem all the time from people changing to LED from Dichoric.
    You need the correct driver for LEDs.
     
  9. Arouse1973

    Arouse1973 Adam

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    Dec 18, 2013
    How are they powered? Do you have a picture of one?
    Adam
     
  10. Lionel44

    Lionel44

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    Jan 11, 2014
    Thanks BJ.
    I bought these LEDs because they were listed as "ac/dc" and I assumed should work off the original Dichroic transformer, as against the normal LEDs which are dc only and as you correctly stated, need a LED driver. My new LEDs light up ok from the transformers except the problem with TV interference!!!
    Have I assumed wrongly and have to buy drivers?
    Are my new LEDs different from the previous type I have installed or have I misread the packaging?
    I have a bit of homework to do over the next few days and I will report back.
     
  11. cjdelphi

    cjdelphi

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    Oct 26, 2011
    Easier to use another power supply...
     
  12. Lionel44

    Lionel44

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    Jan 11, 2014
    Hi Adam, the transformers are 60va electronic transformers for Dichroic down lights. 240v primary, 12v secondary. 50mm x 75mm. Possum brand made by Atco.
     
  13. Lionel44

    Lionel44

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    Jan 11, 2014
    Thanks CJ,
    not what I wanted to hear, but I think you are right.
    I would still like to hear what BJ has to say.
     
  14. Bluejets

    Bluejets

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    Oct 5, 2014
    Like I said, the LEDs do not like the dichoric sw mode driver.
    I can get you the correct number we use, just don't have it handy at the moment.
     
  15. Arouse1973

    Arouse1973 Adam

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    Dec 18, 2013
  16. Lionel44

    Lionel44

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    Jan 11, 2014
    Thanks Adam, the article you have highlighted is from 2012. LEDs have moved on since then, to newer power supplies.
    I won't waste any more of anybodies time. I will buy a couple of Chinese drivers from ebay (I'll bench test them first in case they catch fire!!!) and see how they go before I lash out and buy the rest. I will still follow up with everybody's suggestions just for interest and I will report back.
    Thanks to everyone who contributed - there is a lot of talent out there..

    Lionel
     
  17. Bluejets

    Bluejets

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    Oct 5, 2014
    Nearly all electronics these days originate in China, does not mean they are rubbish.
    One we use are obtained locally and if memory serves correct, cost around Aus$15.00.
    Haven't had time to check the invoices for a part number though as yet.
     
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