Forum Discussion

ZeeLet50's avatar
ZeeLet50
Explorer
Jun 15, 2017

LEDs and radio static

So the latest install of LEDs into my overhead lights is causing some static on weak radio stations. They are the flat type with 24 leds on one side. Very impressed with the brightness about 320 lum but I notices some static. Can I use foil over back of them to shield the interference? What have others tried? Its not bad but just wondering if there are any solutions beside trying another brand.
  • RoyB's avatar
    RoyB
    Explorer II
    Not much you can do - One of the down sides of the high end LED that have built-in REGULATOR chips on them...

    You will also lose your WX RADIO Broadcasts and your HDTV will go blank screen especially when you are using the roof mounted OTA BATWING antenna... Being a HAM RADIO guy I also lost all kinds of frequencies in the LOW and HIGH VHF/UHF bands... Turn off the LED lights and everything jumps back to life. My FM RADIO was not effected by them...

    The LEDs meet the FCC specs but are known to radiate high enough RADIO FREQUENCY Interference NOISE to interfere with your home entertainment items...

    When I changed over I bought about $200 of top end LED items. Had to replace them with the cheap China $4.95 LED boards to work in my trailer. Those did not have the regulator chips on their boards... The REGULATOR CHIPS allows the LED lights to work with a wide range of input DC Voltage...

    The deal back in that time was to never buy a whole bunch of them - Buy just one and see if it works for you haha...

    Search RFI and LED LIGHTs on here to read about them causing Radio Interference

    Roy Ken
  • I got the interference when I changed to LED in our last camper, but it was just the bathroom light. Bought a lot of 10 lights off Amazon. Changed the bathroom light and no more interference. Weird. You might try that.
  • You can try foil (copper foil grounded to the chassis would be the most effective), but a lot of times the radiation from switch mode power supplies is magnetic instead of electric, and a thin faraday shield does almost nothing to attenuate a magnetic field. I'm assuming you are complaining about the AM band, and standard AM antennas are especially sensitive to magnetic field interference because they are a coil around a ferrite bar.

    Sometimes a ferrite toroid RF choke around the 12v feed wires helps too, in case the noise is actually traveling through the 12v supply rather than being radiated over the air.
  • Thanks for the input guys. I am well aware of the chock on the DC input fro the old radio days I put in my cars. Have not tried the TV yet to see how it affects that. I dont do AM at all in the camper but hear some hiss on the weaker FM stations not that the sound systems on these trailers are all that great to begin with.
  • Yes there are things you can do... having some ferrite chokes around will help allot but they need to be right up on the input to the LED plate. Also twist the wires feeding the LED rather tightly as far into the ceiling or wall as to can. Soldering a .001u ceramic cap onto the input of the LED board and again at the output of the switcher will also help, and all three can do wonders. Having a background, none of these should be a big deal

    Having the gear, I tested allot of these solutions several years ago and passed on the findings to one of the big LED manfacturers who went back and re-engineered their devices and are still probably the only ones that ever paid attention to eliminating RFI in these devices. Kudos to them
  • SVCJeff, I assume you mean installing the caps right on the disk board of the LEDs between the powered side and ground. I dont know where the switcher is on the board. As for the "chokes" you mean installing cores with the power wires looped around them? Here is a pic of the LED backside
  • About the only place you can hit the D.C. Input is under the glue at the socket. Up to you if you think you can get one in there. That's a pretty thin tip on the solder station... As mentioned above, look at the input wires and twist them up if you have any slack to do so. Chokes: yes.. you can either buy ferrite rings or over wire clamps. Wish I could remember the spec on the rings I used, but that noise you're seeing is very wide band from around ~75Mhz, all the way past 400Mhz+.
    Nothing is for sure with RFI, but the noisy lamps I've played with have radiated out the D.C. Line more than anything else.
  • Jeff, the two dots next to D3 and D5 are solder joints that run directly off the power inputs so I will put one across there. Thanks again for the info.
  • Ron3rd's avatar
    Ron3rd
    Explorer III
    I get RFI interference on one of my TVs when the led dome lights are on.
  • The caps and ferrite cores came yesterday. I installed the caps on each bulb across the incoming DC connection. Did some tests with the radio and TV. There was no effect on the TV as all stations are good and now with the capacitors in place,there is less static noise on radio with AM or FM when the lights are on then off. It must be filtering the DC line. I have not installed the cores as I don't think they are needed. Problem solved here.
    Thanks to the forum for answers.