Interference from bench lights

Discussion in 'The Projects Forum' started by recklessrog, Aug 27, 2015.

  1. recklessrog

    Thread Starter Well-Known Member

    May 23, 2013
    Recently I moved house and set up a new workbench. In order to "improve" the old one, I scrapped the old filament bulb bench light with a new fluorescent magnifier lamp as advertised by several suppliers. Whilst it works very well as a lamp, it causes havoc when used near sensitive electronic circuits due to its high RF radiation from the high frequency inverter that drives the tube. My advice is that if you have built something that seems to be behaving strangely, before you tear it to bits, turn off any fluoro lights you have on and try it again!! I am going back to incandescent bench lighting!!!
    OBW0549 and nsaspook like this.
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    There are LED lights made to work in the same holders, though you will probably need to change the power they get.

    Someone here reworked an entire shop floor like this to good results.
  3. OBW0549

    Distinguished Member

    Mar 2, 2015
    Most new fluorescent lights, especially CFLs, do spew out huge amounts of electrical hash throughout the lower end of the RF spectrum, including LF, VLF and ELF. It's really annoying. High-power LED lamps such as the Cree 75- and 100-watt tungsten equivalent bulbs put out a lot of electrical noise, too. So do most DC wall-warts, since they contain switching power supplies. Still more hash comes from PCs, laptops and TVs.

    Anymore, I've found that the only way I can work on circuits that are at all sensitive is to use incandescent lights only, and turn everything else off.

    Or do it in the dark.
    wireaddict and nsaspook like this.
  4. TheButtonThief

    Active Member

    Feb 26, 2011
    is the PSU module earthed?
  5. alfacliff

    Well-Known Member

    Dec 13, 2013
    rf noise is a problem, the light itsself is also a problem, a lot of componants are photo sensative, flourescent and led lights have a lot of strobing in their output.
  6. MikeML

    AAC Fanatic!

    Oct 2, 2009
    Most modern lighting uses switch-mode power supplies. Being a Ham, I hate the #$%%$# SMPSs and the crap they radiate into the RF spectrum. I take them out and shoot the damn things with a .22 Rifle. I replace them with DC supply that has a real iron transformer in them.
    wireaddict likes this.
  7. recklessrog

    Thread Starter Well-Known Member

    May 23, 2013
    My yaesu ft950 does a reasonably good job of dealing with "hash" but my poor old ftone gets swamped! I too hate s.m,p's and like you I stick to linear supplies, in fact I sold the s.m.p that came with my linear amp and built a 50volt 30amp psu with a lovely torroidal transformer I had bought at the Newark hamfest. Works a treat!!