LED Lights Interferes with DAB signal

formbypc

Novice Member
OP, or others affected; which radio stations do you listen to?

If these stations are still on FM, why not try an FM radio in the same place?
 

larkone

Member
I did some research on this and came across a lot of boat people complaining that after they had fitted LED lights in their boats they had problems with their comms radios. It would seem that it is the cheaper Chinese made LEDs that cause the biggest issue. It is because of the use of cheap switching power supplies that don't suppress EMI properly.

Interesting article here
Radio interference from LED lighting | EMC and Regulatory Compliance
 

supraTTman

Banned
I did some research on this and came across a lot of boat people complaining that after they had fitted LED lights in their boats they had problems with their comms radios. It would seem that it is the cheaper Chinese made LEDs that cause the biggest issue. It is because of the use of cheap switching power supplies that don't suppress EMI properly.

Interesting article here
Radio interference from LED lighting | EMC and Regulatory Compliance
This is quite surprising. I've completely re-fitted out my boat with 20 odd MR16's from Lustrumlight of various flavours (21/60 LED warm white, cool white) and seen no problems with rf interference with marine VHF/FM/DAB and have no doubt that these are of Far Eastern origin.

I can understand 240V GU10 LED's interfering because LED's need 2.5V DC and so some serious drop in voltage/current is needed by way of an efficient convertor (electronic transformer). Boats are 12V DC and MR16 LED lamps simply wire 3 LED's in series with a 100-200 ohm resistor as with RGB LED flexible strips. Nothing here to generate rf 'trash'.

In short, I can't see why MR16's are causing so many DAB reception problems in homes other than the obvious reason - the 'transformers' are entirely responsible. Some process of elimination is needed to solve these recurring problems as I have suggested all along.
 

Paul W

Standard Member
i also have just been through all these aledged fixes to which none of them worked, except the last one. i have 9 LED lights in the kitchen that ran on 3 electronic trannys perfectly but pee'd the radio and DTV off when they were switched on. only on one TV channel and all DAB stations were affected. it seems only the larger groups of lamps do this (6 or more ) to which i fitted one 12v 10A switchmode DC power supply and hey presto no more problems. in saying that the 6 in the main bedroom dont affect either the TV or radio.... go figure :smashin:
 

supraTTman

Banned
It's all down to the switched-mode power supply you use. They all run at different frequencies (few hundred KHz) and they all generate many harmonics (multiples of few hundred KHz) right up to FM, DAB & TV frequencies (few hundred MHz).

I'm convinced that, in most cases, the source of this interference is not usually the LED 'lamps' themselves for 12V MR16 or similar. For 240V AC GU10's, there is so much voltage conversion circuitry involved to power the 3V DC LED's that these are far more likely to radiate 'mush'.
 

jackord

Standard Member
We live in a suspect area for DTV reception, we have spent a lot of money on getting arial items up to the highest standards, including boosters, arial, cabling etc.

Generally it is summer and early evening when the reception is likely to fail, winter poses no issues at all.

We were running mr16 Halogen lights in our kitchen and living areas, the only noticable thing with them generally was that when we switched on the main kitchen lights (ceiling) often the TV would blink and make a loud noise, but as it was only momentary it was of no concern. If they were contributing to the summer lousy TV reception I do not know.

Anyway after experiencing all the common problems with these dreadfull lights, including them dropping out of their holder due to them being so distored from the heat they generate and nearly hitting our 18mth grandchild on the head (which could have had disastrous consequences) and constantly having to replace them due to this and the worry of fire, I decided to look into the LED scene to see if the prices on the globes had come down to resonable levels to make them a viable purchase.

It seemed that they were now worth a try so a few months back I bought 10 x 4w led mr16 globes (chinese) to replace the 50w halogens.

Sadly they are simply not good enough in the kitchen, but no noticeable TV reception loss, so I went back to the internet and searched for higher capacity globes, found the 3x3 9w cree chip versions, thinking that these would solve the problem I bought some of each colour, 3000k and 6000k.

I did not change the transformers at all, they are the Nelson iron types.

While the lights are much better and in fact for the working areas like the kitchen the 6000k are perfect, and the softer 3000k are nice in areas where you do not want to read, we then by accident I noticed that the DTV would not work (I was complaining that we had no reception at all, could not figure it out, did not make any sense, began to think that there had been some sort of catastopic disaster which stopped the TV stations from broadcasting....lol) then someone turned off the ceiling lights in the kitchen and hey presto on came the TV.

We have 5 in the kitchen, two are wired off the "POWER circuit" which supplies to the range hood and a power point on the wall.
The others are wired off the "LIGHT" circuit in the ceiling.

It is the ceiling ones that stop the TV from working, the others make no difference at all.

We can have two 4w in the TV area on (ceiling, light circuit) and the two (power circuit) ones on with no noticeable TV interference.

So I am wondering why this is the case?

I did experiment with the ceiling lights, as I thought that the transformers may have been at fault.

I disconnected them one at a time and no combination would allow the TV to work. Not even one light on. I then found that I had a couple of Nelson 60VA Cougar Electronic transfomers, so I fitted up two lights with these, tried the TV and it all seemed to work ok, this was during the day. But that evening low and behold, they had the same effect as the other transformers.

I am wondering if TV reception is a bit weaker at night and the slightest interferrence causes it not to work.

Anyway I am at a loss with this and I find it amazing that stuff like this happens. I did not find anything that warned me that LED lights would cause these sorts of problems, just like there was no warning that the Halogen lights were health hazards in so many ways.

With all of the consumer protection we have around these days one wonders how these sorts of products can be marketed.

Anyway if anybody has a solution it would be appreciated as I know nothing about electronics.

Cheers
 

jackord

Standard Member
i also have just been through all these aledged fixes to which none of them worked, except the last one. i have 9 LED lights in the kitchen that ran on 3 electronic trannys perfectly but pee'd the radio and DTV off when they were switched on. only on one TV channel and all DAB stations were affected. it seems only the larger groups of lamps do this (6 or more ) to which i fitted one 12v 10A switchmode DC power supply and hey presto no more problems. in saying that the 6 in the main bedroom dont affect either the TV or radio.... go figure :smashin:
You will have to excuse my ignorance, but am I to assume that you are simply running your 12v LED lights straight off the power supply (no transformer) also am I to assume that this is the same sort of thing that is used in PC's?

It makes sense that they would work like that after all they only need 12v to operate.

So if one had a spare 300w computer power supply all one would need to do would be to fit a 3 pin plug to the light cable in the ceiling, then plug the PC power supply into there, then wire up the LED downlights to the 12v outputs, of which there are usually at least 6.

Having said all of that, it seems that most switched mode power supplies can be a source of EMI, hence the issue with the transformers used for the LED lights. The ATX PC powersupplies, do have an EMI filter.

Sounds like a nice weekend project coming up.
 

Paul W

Standard Member
You will have to excuse my ignorance, but am I to assume that you are simply running your 12v LED lights straight off the power supply (no transformer) also am I to assume that this is the same sort of thing that is used in PC's?

It makes sense that they would work like that after all they only need 12v to operate.

So if one had a spare 300w computer power supply all one would need to do would be to fit a 3 pin plug to the light cable in the ceiling, then plug the PC power supply into there, then wire up the LED downlights to the 12v outputs, of which there are usually at least 6.

Having said all of that, it seems that most switched mode power supplies can be a source of EMI, hence the issue with the transformers used for the LED lights. The ATX PC powersupplies, do have an EMI filter.

Sounds like a nice weekend project coming up.
Sort of. These are not out of a computer or anything, they are a universal 12v 12.5A switchmode power supply made by" MeanWell ". i have now installed several of these on the troublesome groups of lights and all the problems have gone away.:clap: i could run the whole house on one of those things :laugh:
 

jackord

Standard Member
Thanks for your reply Paul W.

I have been fiddling and now I am able to run 3 x 6000k off one transformer and 2 x 6000k of another without any ill effects on the TV.

It is quite usual for one to simply buy the LED globes and fit them as replacements, thereby leaving all of the original transformers in place. It never occurs to people that they do NOT need all of those transformers. They are designed to run 50w globes so you can work out how many LED globes could be run off of one transformer, the only problem is how to connect them all up. Making up a suitable wiring harness and finding a suitable connection box is the next thing for me.

Switching is an issue as we like to have different banks of lights independantly switched, which would mean using a transformer for each set of lights, which sounds like what you have done Paul?

If one was building a new house all of this could be worked out quite easily. But retrofitting is a bit harder.

I will press on as I have now spent the money on the 12v system. But I am sure that I can get some sort of satisfactory arrangement done.

The Computer PSU works fine, if one wanted to make up a wiring harness to fit into the original wiring plugs on the PSU, then run them out to the light bulbs, then mount the PSU in the ceiling safely so that animals cannot tip it over or pee on it or whatever, only issue is that they run a fan so that will be on whenever the lights are on, this adds about 7w to the power usage. But once again you would need one of these for each set of lights that you want independantly switched.

Oh well...........
 

Paul W

Standard Member
when i was experimenting i found anything from 1 to a maximum of 4 LEDs were OK on 1 electronic transformer, if i added a 5th it would start to flicker and carry on after about an hour,pull it back to 4 and it was OK. i just recieved another 20 LED lamps today so i now can finish off the entire house retrofit and remove the uneccessary transformers, then see which other groups of lights start the TV carrying on and change them to the switchmode power supply.:smashin:
 

daniel2002

Novice Member
You will have to excuse my ignorance, but am I to assume that you are simply running your 12v LED lights straight off the power supply (no transformer) also am I to assume that this is the same sort of thing that is used in PC's?

It makes sense that they would work like that after all they only need 12v to operate.

So if one had a spare 300w computer power supply all one would need to do would be to fit a 3 pin plug to the light cable in the ceiling, then plug the PC power supply into there, then wire up the LED downlights to the 12v outputs, of which there are usually at least 6.

Having said all of that, it seems that most switched mode power supplies can be a source of EMI, hence the issue with the transformers used for the LED lights. The ATX PC powersupplies, do have an EMI filter.

Sounds like a nice weekend project coming up.
Sounds like a good plan.
 

Chris Muriel

Distinguished Member
Some LED bulbs create large amounts of RF interference- while others are properly designed with good suppression and filtering included.
Interesting video on the subject here :
 

Fudgemia

Standard Member
i had 8 halogen spotlights in my kitchen, one blew so i replaced with a Lumineux High Powered LED GU10 4.5w 230v. this had a life of 30,000 hours and would save a fortune in electricity. there was no need to change transformers they just plug straight into the existing bulb holder.

turned the one bulb on my DAB radion stopped recieving signal, all lights still on the radio but no sound. Moved it around different sockets in different rooms still didn't work. Tried windup DAB so it didn't need plugging in i had to take it out of the house before it worked.

Anyone able to help, what do i get rid of my DAB radio, can't too much choice of stations, or my LED bulbs.
 

Fudgemia

Standard Member
I tried replacing the LED bulb that stopped the DAB radio working, following discussions with the supplier, with a different type (warm white as opposed to cool white). this had no effect it still stopped the DAB Radio working. thanks for the suggestion.
 

Rodders53

Distinguished Member
I tried replacing the LED bulb that stopped the DAB radio working, following discussions with the supplier, with a different type (warm white as opposed to cool white). this had no effect it still stopped the DAB Radio working. thanks for the suggestion.
That one, too if faulty or poorly designed (probably the latter)... although you may, perhaps, also be in a marginal reception location and more liable to interference.
 

Chris Muriel

Distinguished Member
Different type - but if the same make would likely be a similar design and create similar amounts of interference.
 

rp2044

Standard Member
Hi all,
I'm a researcher in to light bulbs for a consumer magazine and I'm just looking in to this problem as we have also heard about it. Can anyone tell me specifically which brand/ make/ model of LED bulbs is causing this problem? we would like to purchase them and test them ourselves.
Many thanks for any help!
 

gr0mit

Standard Member
Hi
I'm just sending 5 of these back as faulty/non-compliant to EMC regulations:
MASSIVE SAVINGS on MR16 LED Bulb 320 Lumens 50W Equiv

Lights on, DAB off! Lights off, DAB on!

I got a 12v lead acid battery and connected the string of 5 lights directly to that instead of the mains torroidal transformer, and it still interfered with the DAB radio. Conclusion: These particular lights are causing a lot of RF noise in the 150-200MHz spectrum.
Rgds
gr0mit
 

4stringstu

Standard Member
I have exactly the same thing with fluorecent tubes. I can get occasional reception but a small change in arial position stops it working
 

Wildestcat

Standard Member
I have 4 x ALT 100V-240V 7W wide angle warm white GU10 LEDs on a seperately switched circuit in the kitchen/diner. The room also has 3 other seperately switched circuits carrying a total of 12 x 4W Kosnic warm white LEDs.

Switch on the ALT circuit - DAB radio goes off, switch off the ALT circuit, DAB back on. Had to move radio to the far end of kitchen (directly below one of the Kosnic arrays) before reception returns with the ALTs energised 4 metres away.

I have tried the radio on internal battery power - problem is unchanged, so nothing to do with connection to the mains. Tried a single ALT bulb with the other 3 removed - one ALT bulb is enough on its own to cause the problem.

There are NO issues with the DAB radio anywhere within the room with all the Kosnics in use, plus Kosnics in place of the ALTs. (i.e. total of 16 x 4W 220V-240V Kosnic has no adverse effect on DAB radio).

Note there are no transformers involved on any circuit - all bulbs plug straight into 240V light circuits.

In my opinion the issue is with whatever electronics are fitted in the ALT bulbs (could this be linked to the wider 100V-240V input voltage range?). In future I will be buying Kosnic, although sadly they do not offer a bulb with the equivalent lumens or beam spread of the ALTs.

Hope that may help anyone with similar issues!
 
Last edited:

Wildestcat

Standard Member
Have now found that Kosnic do offer a 6W wide angle GU10 replacement that is as good as the ALT.
Part no KTC06PWR/GU-10-F30.
Now installed & no DAB radio interference!
 

supraTTman

Banned
Have now found that Kosnic do offer a 6W wide angle GU10 replacement that is as good as the ALT.
Part no KTC06PWR/GU-10-F30.
Now installed & no DAB radio interference!
Intriguing - was there much difference in price between the ALT & the Kosnic lamps? Are they both made in China?
 

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