# Interference from bench lights

#### recklessrog

Joined May 23, 2013
988
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!!!

#### ErnieM

Joined Apr 24, 2011
7,991
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.

#### OBW0549

Joined Mar 2, 2015
2,952
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.

#### TheButtonThief

Joined Feb 26, 2011
232
is the PSU module earthed?

#### alfacliff

Joined Dec 13, 2013
2,449
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.

#### MikeML

Joined Oct 2, 2009
5,444
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.

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.