LED landing lights causing radio interference.
Thread Starter
Joined: Jun 2008
Posts: 519
Likes: 16
From: Luton
LED landing lights causing radio interference.
We have fitted LED landing lights into a Robin DR400 and find that they interfere with the radio. I believe that is because they have ‘switched mode’ or ‘buck converter’ power supplies integrated that can, if not properly designed, emit radio frequency noise.
Has anybody else experienced this? If so, what was the cure?
Has anybody else experienced this? If so, what was the cure?
Joined: Jul 2010
Posts: 2,807
Likes: 10
From: Ansião (PT)
Since no make or model of the lights is mentioned, only some generalities:
* consider adding filtering in the supply line - typically a coil in series, and at each side a C to ground; the C's with good HF properties, ceramic might do well. One can buy these as "black boxes", they are sometimes called "pi-filter"s
* Install this/these filter(s) as close as possible to the (rightly!) suspect power switcher(s). It might even be useful to add such a filter at each end of the supply line - that line making a fairly effective transmitter antenna
* the Robin being wood built, check grounding. Ideally, all ground lines go to one central point - some implement that as a strip/bar of brass, others use a bolt that stacks the cable eyes terminating the various ground wires.
* consider adding filtering in the supply line - typically a coil in series, and at each side a C to ground; the C's with good HF properties, ceramic might do well. One can buy these as "black boxes", they are sometimes called "pi-filter"s
* Install this/these filter(s) as close as possible to the (rightly!) suspect power switcher(s). It might even be useful to add such a filter at each end of the supply line - that line making a fairly effective transmitter antenna
* the Robin being wood built, check grounding. Ideally, all ground lines go to one central point - some implement that as a strip/bar of brass, others use a bolt that stacks the cable eyes terminating the various ground wires.
Joined: Jul 2010
Posts: 2,807
Likes: 10
From: Ansião (PT)
I don't think the brand is very relevant, though I did hint so - sorry! Except if someone would have the exact same, but these things are so easy to design that there must be dozens of makes and models on the market.
Perhaps - as you guess - the switching regulator is crap; but it is also possible the installation is, err, less than perfect.
Perhaps - as you guess - the switching regulator is crap; but it is also possible the installation is, err, less than perfect.
Last edited by Jan Olieslagers; 20th October 2016 at 08:19.
Joined: Aug 1998
Posts: 2,033
Likes: 14
From: London, UK
I was at a gliding club the other day and they could only use one of their DR400 tugs as the weather required flying with the LED landing lights on and one of them suffered from similar radio interference - the other did not.
