LED lighting radio interference

PeterVahry
Hard Yaka
Posts: 688
Joined: Wed Mar 01, 2006 12:00 pm
Location: Auckland

LED lighting radio interference

Postby PeterVahry » Sat Nov 08, 2014 7:57 pm

Radio Spectrum Management (RSM) works with logging industry to solve LED lighting interference

RSM has identified serious cases of interference to radio communications at log hauler sites in Marlborough from the operation of vehicle mounted LED lighting. The interference is so severe that in darkness hours radio systems have become inoperable. Site management called RSM to look at the issue due to serious safety concerns.

A common solution was to separate the lights from the radio antennas as much as physically possible.

A recent audit of emergency lighting suppliers was undertaken by RSM and it was generally found that suppliers were not aware of the need to ensure their equipment met the necessary EMC specification AS/NZS CISPR15.

A further finding was that various other electronics fitted to the diggers and haulers caused radio interference. In this case most instances of interference can be minimised by placing the radio antenna centrally on the cabin roof.

RSM urges users to ensure they pay attention to the separation of antennas from other electronics and only fit approved AS/NZS CISPR15 LED lights.

User avatar
Crash bandicoot
Hard Yaka
Posts: 2924
Joined: Thu Dec 30, 2010 7:19 pm
Location: Towing a hilux

Re: LED lighting radio interference

Postby Crash bandicoot » Sat Nov 08, 2014 8:24 pm

before any one goes jumping on the bandwagon you should have qualified that statement.

Top quality lights do not create this interference, it would appear that interference with remotes, garage door openers, VHF radio etc is being subjected to interference from low grade LED's.

The interference is becoming an issue in the 30 – 300 MHz range, and is created by higher then necessary input voltage, the result being the LED pulses to create an average light output. the downside to this is the pulsating creates a EMI discharge.

An example of this would be buying say (for example) a supercheap LED light set that only requires 4-12 volts but can accept voltages from up to 32 volts without damaging themselves. In a vehicle application where the LED only required 4 volts but 12 volts is supplied the LED regulates itself by discharging the excess as a EMI.

most top quality LED lights are designed to operate on "just enough" voltage so the LED has no need to regulate itself by pulsing.

Contractors(or anyone) buying and using imported non compliant LED lights are there own enemy in this aspect.

The E.U and FCC in the U.S.A are currently investigating this issue as the use of LED lighting becomes more prevalent in all aspects of industry and private use from mining and forestry to transport and domestic home use.

I have over(individual) 100 high spec LED's wired up in series groups of 4(3 volt draw each) in two housings on the roof of my truck and the 5 watt antenna sits right next to them and have had never had an issue receiving or had reports of fading/static or poor transmission from anyone i have talked too over my radio.
Waiter...there is a drought in my glass.

User avatar
UBZ
Hard Yaka
Posts: 1630
Joined: Sat Aug 19, 2006 12:00 pm
Location: Twizel

Re: LED lighting radio interference

Postby UBZ » Sat Nov 08, 2014 8:50 pm

EFI and RF interferance from poor quality electronics is nothing new . especially from LEDs .

Your vehicle acts as a large capacitor ,creating an artifical ground plane for the antenna.

bad bonding / earthing of the vehicle and antennas , combined with electrically noisey electronics upsets the ground plane reference.
It can render radios unintelligible .

The main cause of problems is earthing electric circuits through the body instead of running earths back to the battery .
LR110 ..... LJ50 project :roll:
Chris.

User avatar
tweake
Hard Yaka
Posts: 2211
Joined: Tue Jan 01, 2008 12:00 pm
Location: start of northland

Re: LED lighting radio interference

Postby tweake » Sat Nov 08, 2014 9:11 pm

Crash bandicoot wrote:before any one goes jumping on the bandwagon you should have qualified that statement.

Top quality lights do not create this interference, it would appear that interference with remotes, garage door openers, VHF radio etc is being subjected to interference from low grade LED's.

The interference is becoming an issue in the 30 – 300 MHz range, and is created by higher then necessary input voltage, the result being the LED pulses to create an average light output. the downside to this is the pulsating creates a EMI discharge.

An example of this would be buying say (for example) a supercheap LED light set that only requires 4-12 volts but can accept voltages from up to 32 volts without damaging themselves. In a vehicle application where the LED only required 4 volts but 12 volts is supplied the LED regulates itself by discharging the excess as a EMI.

most top quality LED lights are designed to operate on "just enough" voltage so the LED has no need to regulate itself by pulsing.


that doesn't sound right to me.

its not the led's that cause interference but the drivers that run them. the driver regulates the voltage and current that the led receives, that way it runs at max without burning out. especially with vehicles due to their running voltage being higher than when the engine is off (14v vers 12v)
cheap led's often don't have drivers at all and operate on "just enough" voltage so the LED has no need to regulate itself by pulsing.
cheap drivers for leds could cause issues due to the frequency the driver runs at.

zedz
Winch master
Posts: 13
Joined: Tue Oct 28, 2014 12:38 pm

Re: LED lighting radio interference

Postby zedz » Mon Nov 10, 2014 9:26 am

This is a problem that is well know throughout industry.
Industry way to avoid this is to have the LED drivers tuned to your frequency or house them in a RFI housing with line arrestors to stop line RFI & radiated RFI.
High quality LED lighting should have tuned drivers & line arrestors built in.
Wire Mesh impregnated glass is a option but very expensive.

It doesn't matter what type of LED lighting you have, if its not setup for your frequency RFI can be a problem.

User avatar
Gyxx
Hard Yaka
Posts: 180
Joined: Wed Jul 03, 2013 12:34 am
Location: Wellington

Re: LED lighting radio interference

Postby Gyxx » Tue Nov 11, 2014 12:19 am

It's become a common problem in other circles too over the past few years. On boating forums there's any number of threads along the lines of "I just installed LED lights, now I'm having problems with my radios/ electronics". I've met quite a few drivers who've retro-fitted LEDs to interior lights or overhead consoles (usually only a few inches away from their CBs and RTs) and have ended up pulling them out in frustration and re-fitting incandescent bulbs.
Quite often El-cheapo lights that don't meet the required specs and spew RFI are the problem but even the quality gear can cause problems when no thoughts been given to antenna locations, cable runs and proper earthing/ shielding.
The radio spectrum's become a much more crowded and noisy place over the past few years and the amount of sub-standard gear being imported and sold over the internet with little or no policing of the regulations certainly hasn't helped.
Personally I'm hoping that as LED lighting starts to take off in the domestic market that some attention might be paid to the RFI issue.

Return to “4wd Safety”

Who is online

Users browsing this forum: No registered users and 0 guests