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Do LED bulbs interfere with DAB radio?



 
 
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  #1  
Old December 28th 16, 10:33 AM posted to uk.tech.digital-tv
Dave W
external usenet poster
 
Posts: 213
Default Do LED bulbs interfere with DAB radio?


"Scott" wrote in message
...
On Mon, 26 Dec 2016 13:59:55 -0000, "Woody"
wrote:


"Scott" wrote in message
. ..
I installed LED spotlights in the kitchen and when they are all on
the
DAB radio stops working. I am wondering if this is due to:

1. A general problem with LED lighting (in which case is it fit for
purpose for domestic use?)
2. A single faulty bulb
3. A particular issue with 12 Volt bulbs

I should explain this is a somewhat unusual installation. The
lights
are powered by torroidal transformers (for which I am assured there
is
no minimum load). The transformers are a long way from the radio
and
have never previously caused difficulties, so I am convinced the
problems lie with the bulbs themselves.

A quick search suggests that the problem could be Electromagnetic
Compatibility (EMC) or lack of it.

Any ideas among the experts?


Questions in advance of the expert start: do you normally get a good
signal on DAB? There is usually somewhere in the menu system a signal
strength indication

Yes - signal error between varies 3 and 5. I'm in a top floor flat so
DAB reception is not normally a problem.
- does this indication vary between lights on and
lights off?

Yes - with all the lights on it goes to 'No audio'.
Does the indication vary with the number of lamps lit?

Yes.
What is the nature of the DAB problem - does it go to bubbling mud or
does the radio just mute?

It deteriorates to bubbling mud as the lights are turned on. The ones
closest cause the biggest problem.
That's a start.

And thanks for that.

They are MR16 lamps (14 in total). I'm also going to write to the
supplier to see if they are EMC compliant. No mention of this on the
box (however, as the wattage and halogen equivalence are both wrong on
the box due to a 'printing error' I am not very confident about any of
the information I am being given..


As far as I can tell, you have a simple transformer providing 12V AC to each
group of lamps. The lamps only run on 50Hz AC. They each have an internal
SMPS to drive the LEDs.

You could switch on just the worst bulb, then move the radio along the route
between the transformer and the bulb, to see whether the interference is
coming from the wire or just the bulb.

If it's the wire, you might be able to add a suppressor near each bulb but I
doubt if it would be economically viable owing to the high current peaks
involved. Or maybe the wire could be screened. I doubt that the interference
would get past the transformer into the mains, especially as you say the
nearest bulbs give the most interference.

If it's the bulb alone, assuming it's a genuine Philips, you're stuck.
--
Dave W


  #2  
Old December 28th 16, 03:41 PM posted to uk.tech.digital-tv
Scott[_2_]
external usenet poster
 
Posts: 1,171
Default Do LED bulbs interfere with DAB radio?

On Wed, 28 Dec 2016 11:33:44 -0000, "Dave W"
wrote:


"Scott" wrote in message
.. .
On Mon, 26 Dec 2016 13:59:55 -0000, "Woody"
wrote:


"Scott" wrote in message
...
I installed LED spotlights in the kitchen and when they are all on
the
DAB radio stops working. I am wondering if this is due to:

1. A general problem with LED lighting (in which case is it fit for
purpose for domestic use?)
2. A single faulty bulb
3. A particular issue with 12 Volt bulbs

I should explain this is a somewhat unusual installation. The
lights
are powered by torroidal transformers (for which I am assured there
is
no minimum load). The transformers are a long way from the radio
and
have never previously caused difficulties, so I am convinced the
problems lie with the bulbs themselves.

A quick search suggests that the problem could be Electromagnetic
Compatibility (EMC) or lack of it.

Any ideas among the experts?

Questions in advance of the expert start: do you normally get a good
signal on DAB? There is usually somewhere in the menu system a signal
strength indication

Yes - signal error between varies 3 and 5. I'm in a top floor flat so
DAB reception is not normally a problem.
- does this indication vary between lights on and
lights off?

Yes - with all the lights on it goes to 'No audio'.
Does the indication vary with the number of lamps lit?

Yes.
What is the nature of the DAB problem - does it go to bubbling mud or
does the radio just mute?

It deteriorates to bubbling mud as the lights are turned on. The ones
closest cause the biggest problem.
That's a start.

And thanks for that.

They are MR16 lamps (14 in total). I'm also going to write to the
supplier to see if they are EMC compliant. No mention of this on the
box (however, as the wattage and halogen equivalence are both wrong on
the box due to a 'printing error' I am not very confident about any of
the information I am being given..


As far as I can tell, you have a simple transformer providing 12V AC to each
group of lamps. The lamps only run on 50Hz AC. They each have an internal
SMPS to drive the LEDs.


Yes, essentially.

You could switch on just the worst bulb, then move the radio along the route
between the transformer and the bulb, to see whether the interference is
coming from the wire or just the bulb.


Don't think there is worst bulb. What I have found is that the group
nearest the radio causes the most interference.

If it's the wire, you might be able to add a suppressor near each bulb but I
doubt if it would be economically viable owing to the high current peaks
involved. Or maybe the wire could be screened. I doubt that the interference
would get past the transformer into the mains, especially as you say the
nearest bulbs give the most interference.


The bulbs are in a track so I could only suppress the track.

If it's the bulb alone, assuming it's a genuine Philips, you're stuck.


Not Philips. The bulbs are Lumilife. I was suggesting Philips as a
potential replacement. I see they are now in John Lewis.
  #3  
Old December 31st 16, 03:36 PM posted to uk.tech.digital-tv
Dave W
external usenet poster
 
Posts: 213
Default Do LED bulbs interfere with DAB radio?


"Scott" wrote in message
...
On Wed, 28 Dec 2016 11:33:44 -0000, "Dave W"
wrote:


"Scott" wrote in message
. ..
On Mon, 26 Dec 2016 13:59:55 -0000, "Woody"
wrote:


"Scott" wrote in message
m...
I installed LED spotlights in the kitchen and when they are all on
the
DAB radio stops working. I am wondering if this is due to:

1. A general problem with LED lighting (in which case is it fit for
purpose for domestic use?)
2. A single faulty bulb
3. A particular issue with 12 Volt bulbs

I should explain this is a somewhat unusual installation. The
lights
are powered by torroidal transformers (for which I am assured there
is
no minimum load). The transformers are a long way from the radio
and
have never previously caused difficulties, so I am convinced the
problems lie with the bulbs themselves.

A quick search suggests that the problem could be Electromagnetic
Compatibility (EMC) or lack of it.

Any ideas among the experts?

Questions in advance of the expert start: do you normally get a good
signal on DAB? There is usually somewhere in the menu system a signal
strength indication
Yes - signal error between varies 3 and 5. I'm in a top floor flat so
DAB reception is not normally a problem.
- does this indication vary between lights on and
lights off?
Yes - with all the lights on it goes to 'No audio'.
Does the indication vary with the number of lamps lit?
Yes.
What is the nature of the DAB problem - does it go to bubbling mud or
does the radio just mute?
It deteriorates to bubbling mud as the lights are turned on. The ones
closest cause the biggest problem.
That's a start.
And thanks for that.

They are MR16 lamps (14 in total). I'm also going to write to the
supplier to see if they are EMC compliant. No mention of this on the
box (however, as the wattage and halogen equivalence are both wrong on
the box due to a 'printing error' I am not very confident about any of
the information I am being given..


As far as I can tell, you have a simple transformer providing 12V AC to
each
group of lamps. The lamps only run on 50Hz AC. They each have an internal
SMPS to drive the LEDs.


Yes, essentially.

You could switch on just the worst bulb, then move the radio along the
route
between the transformer and the bulb, to see whether the interference is
coming from the wire or just the bulb.


Don't think there is worst bulb. What I have found is that the group
nearest the radio causes the most interference.

If it's the wire, you might be able to add a suppressor near each bulb but
I
doubt if it would be economically viable owing to the high current peaks
involved. Or maybe the wire could be screened. I doubt that the
interference
would get past the transformer into the mains, especially as you say the
nearest bulbs give the most interference.


The bulbs are in a track so I could only suppress the track.

If it's the bulb alone, assuming it's a genuine Philips, you're stuck.


Not Philips. The bulbs are Lumilife. I was suggesting Philips as a
potential replacement. I see they are now in John Lewis.


I think you said you have three bulbs per transformer. The link to the
transformer you gave was for a 100W 24V. You have 12V but I assume the
transformers are still 100W. Each would have driven three 35W halogen bulbs,
so I assume your replacement LED bulbs give the equivalent light output,
i.e. the Lumilife 4.8W MR16.

I tried to find out more information about these. They are sold by many
firms online but all come from LED-hut. That site gives no indication about
where the bulbs come from, so it seems they are an imported 'own brand', and
there is no full specification available. You would do well to try three
Philips bulbs instead, although even Philips spec doesn't say anything about
RF interference.

They are the Philips CorePro LEDspot LV, available in two colour
temperatures: 4000 at 4.7W, and 3700 at 5.5W.
--
Dave W


  #4  
Old December 31st 16, 04:06 PM posted to uk.tech.digital-tv
Woody[_5_]
external usenet poster
 
Posts: 1,583
Default Do LED bulbs interfere with DAB radio?


"Dave W" wrote in message
news

"Scott" wrote in message
...
On Wed, 28 Dec 2016 11:33:44 -0000, "Dave W"
wrote:


"Scott" wrote in message
...
On Mon, 26 Dec 2016 13:59:55 -0000, "Woody"

wrote:


"Scott" wrote in message
om...
I installed LED spotlights in the kitchen and when they are all
on
the
DAB radio stops working. I am wondering if this is due to:

1. A general problem with LED lighting (in which case is it
fit for
purpose for domestic use?)
2. A single faulty bulb
3. A particular issue with 12 Volt bulbs

I should explain this is a somewhat unusual installation. The
lights
are powered by torroidal transformers (for which I am assured
there
is
no minimum load). The transformers are a long way from the
radio
and
have never previously caused difficulties, so I am convinced
the
problems lie with the bulbs themselves.

A quick search suggests that the problem could be
Electromagnetic
Compatibility (EMC) or lack of it.

Any ideas among the experts?

Questions in advance of the expert start: do you normally get a
good
signal on DAB? There is usually somewhere in the menu system a
signal
strength indication
Yes - signal error between varies 3 and 5. I'm in a top floor
flat so
DAB reception is not normally a problem.
- does this indication vary between lights on and
lights off?
Yes - with all the lights on it goes to 'No audio'.
Does the indication vary with the number of lamps lit?
Yes.
What is the nature of the DAB problem - does it go to bubbling
mud or
does the radio just mute?
It deteriorates to bubbling mud as the lights are turned on. The
ones
closest cause the biggest problem.
That's a start.
And thanks for that.

They are MR16 lamps (14 in total). I'm also going to write to
the
supplier to see if they are EMC compliant. No mention of this on
the
box (however, as the wattage and halogen equivalence are both
wrong on
the box due to a 'printing error' I am not very confident about
any of
the information I am being given..

As far as I can tell, you have a simple transformer providing 12V
AC to each
group of lamps. The lamps only run on 50Hz AC. They each have an
internal
SMPS to drive the LEDs.


Yes, essentially.

You could switch on just the worst bulb, then move the radio along
the route
between the transformer and the bulb, to see whether the
interference is
coming from the wire or just the bulb.


Don't think there is worst bulb. What I have found is that the
group
nearest the radio causes the most interference.

If it's the wire, you might be able to add a suppressor near each
bulb but I
doubt if it would be economically viable owing to the high current
peaks
involved. Or maybe the wire could be screened. I doubt that the
interference
would get past the transformer into the mains, especially as you
say the
nearest bulbs give the most interference.


The bulbs are in a track so I could only suppress the track.

If it's the bulb alone, assuming it's a genuine Philips, you're
stuck.


Not Philips. The bulbs are Lumilife. I was suggesting Philips as
a
potential replacement. I see they are now in John Lewis.


I think you said you have three bulbs per transformer. The link to
the transformer you gave was for a 100W 24V. You have 12V but I
assume the transformers are still 100W. Each would have driven three
35W halogen bulbs, so I assume your replacement LED bulbs give the
equivalent light output, i.e. the Lumilife 4.8W MR16.

I tried to find out more information about these. They are sold by
many firms online but all come from LED-hut. That site gives no
indication about where the bulbs come from, so it seems they are an
imported 'own brand', and there is no full specification available.
You would do well to try three Philips bulbs instead, although even
Philips spec doesn't say anything about RF interference.

They are the Philips CorePro LEDspot LV, available in two colour
temperatures: 4000 at 4.7W, and 3700 at 5.5W.
--



Now you see therein lies another puzzle.

Why do manufacturers choose 'odd' colour temperatures. If they are
replacing incandescent bulbs then they need to be around 2300K to
colour match, if they are replacing halogen then they need to be a bit
higher - somewhere around 2700-3000K. So why are Philips making a bulb
at 4000K which is more like the colur of a daylight white fluorescent
tube? Barmy to my mind.

I have just replaced six 35W GU10 bulbs in a fitting in my dining
room. The new LED bulbs are listed at 'warm white' but when I got them
home they were/are 3000K which is much brighter and whiter than the
bulbs they replaced. What is more the colour does not change as they
are dimmed, only the light level changes. Whilst it means you can see
your food better it doesn't look anything like so hospitable!


--
Woody

harrogate3 at ntlworld dot com


  #5  
Old December 31st 16, 04:12 PM posted to uk.tech.digital-tv
Scott[_2_]
external usenet poster
 
Posts: 1,171
Default Do LED bulbs interfere with DAB radio?

On Sat, 31 Dec 2016 16:36:57 -0000, "Dave W"
wrote:

[snip]

I think you said you have three bulbs per transformer. The link to the
transformer you gave was for a 100W 24V. You have 12V but I assume the
transformers are still 100W. Each would have driven three 35W halogen bulbs,
so I assume your replacement LED bulbs give the equivalent light output,
i.e. the Lumilife 4.8W MR16.


It was three transformers, one for each track. Two of the tracks
contain five spots and one contains four. The transformer in the link
was only for illustration. Each halogen spot was 50W. The Lumilife
bulbs are 7.5W on the website (though 6.5W on the box).

I tried to find out more information about these. They are sold by many
firms online but all come from LED-hut. That site gives no indication about
where the bulbs come from, so it seems they are an imported 'own brand', and
there is no full specification available. You would do well to try three
Philips bulbs instead, although even Philips spec doesn't say anything about
RF interference.


Thanks for investigating. LED Hut seem to be conceding there is a
problem with DAB (for 12V lamps only). The bulbs come from China.

They are the Philips CorePro LEDspot LV, available in two colour
temperatures: 4000 at 4.7W, and 3700 at 5.5W.


Screwfix are doing three 8.2W units for 16.99
http://www.screwfix.com/p/philips-mr...w-3-pack/6415p
(I need a lot of light as it is high ceilings and these are the main
room lights.)

PS I have started a new thread on Philips.
  #6  
Old January 1st 17, 11:13 AM posted to uk.tech.digital-tv
Jim Lesurf[_2_]
external usenet poster
 
Posts: 4,126
Default Do LED bulbs interfere with DAB radio?

In article , Woody
wrote:

Why do manufacturers choose 'odd' colour temperatures. If they are
replacing incandescent bulbs then they need to be around 2300K to
colour match, if they are replacing halogen then they need to be a bit
higher - somewhere around 2700-3000K. So why are Philips making a bulb
at 4000K which is more like the colur of a daylight white fluorescent
tube? Barmy to my mind.


The history IIRC is that the early generations of high efficiency 'white'
LEDs use(d) blue/UV LEDs along with phosphors to convert some of that into
other wavelengths to get 'white'. The results tended to have to lean
towards the blue for efficiency reasons.

IEEE Spectrum did an article on this some time ago. One result of the above
is that many locations adopted the new LEDs for street lighting to save
power/money. They now realise those LEDs are uncomfortably 'blue' and need
replacing.

Later types give lower colour temperatures. But the early ones might be
cheaper to make at present. What I don't know is if it is still the case
that to get the 'warmer' temperatures you still end up with lower
efficiency and/or high cost.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

  #7  
Old January 1st 17, 01:33 PM posted to uk.tech.digital-tv
Max Demian
external usenet poster
 
Posts: 3,668
Default Do LED bulbs interfere with DAB radio?

On 01/01/2017 12:13, Jim Lesurf wrote:
In article , Woody
wrote:

Why do manufacturers choose 'odd' colour temperatures. If they are
replacing incandescent bulbs then they need to be around 2300K to
colour match, if they are replacing halogen then they need to be a bit
higher - somewhere around 2700-3000K. So why are Philips making a bulb
at 4000K which is more like the colur of a daylight white fluorescent
tube? Barmy to my mind.


The history IIRC is that the early generations of high efficiency 'white'
LEDs use(d) blue/UV LEDs along with phosphors to convert some of that into
other wavelengths to get 'white'. The results tended to have to lean
towards the blue for efficiency reasons.

IEEE Spectrum did an article on this some time ago. One result of the above
is that many locations adopted the new LEDs for street lighting to save
power/money. They now realise those LEDs are uncomfortably 'blue' and need
replacing.


Why does it matter with street lights? No-one (effectively) complained
about the (bluish) mercury lights or even low (yellow) and high (pink)
pressure sodium lights.

--
Max Demian
  #8  
Old January 1st 17, 02:32 PM posted to uk.tech.digital-tv
Woody[_5_]
external usenet poster
 
Posts: 1,583
Default Do LED bulbs interfere with DAB radio?


"Jim Lesurf" wrote in message
...
In article , Woody

wrote:

Why do manufacturers choose 'odd' colour temperatures. If they are
replacing incandescent bulbs then they need to be around 2300K to
colour match, if they are replacing halogen then they need to be a
bit
higher - somewhere around 2700-3000K. So why are Philips making a
bulb
at 4000K which is more like the colur of a daylight white
fluorescent
tube? Barmy to my mind.


The history IIRC is that the early generations of high efficiency
'white'
LEDs use(d) blue/UV LEDs along with phosphors to convert some of
that into
other wavelengths to get 'white'. The results tended to have to lean
towards the blue for efficiency reasons.

IEEE Spectrum did an article on this some time ago. One result of
the above
is that many locations adopted the new LEDs for street lighting to
save
power/money. They now realise those LEDs are uncomfortably 'blue'
and need
replacing.

Later types give lower colour temperatures. But the early ones might
be
cheaper to make at present. What I don't know is if it is still the
case
that to get the 'warmer' temperatures you still end up with lower
efficiency and/or high cost.



I have to say I would prefer SOX fittings - preferably the high
pressure lamps with the gold light - to LED any day. I don't
understand why but the 'daylight' white of LEDs doesn't seem to light
objects - especially people - in the same way that limited spectrum
lights do.

I remember as a child travelling back to Leicester from Chesterfield
having visited family and going through Derby where flourescent street
lights were the norm. It made it very difficult to see where you were
going especially if it was foggy, which suggests that colour has a
significant part to play.

I think however I may have accidently found out more about it. We have
a PIR switched lamp on our shed which has a habit of lighting up at
night for no apparent reason. To reduce consumption yesterday I
replaced the R7s 100W 78mm halogen fitting with a 20W LED reflector
unit, and I went outside last night to test it. What was immediately
obvious was that the LED lamp lit things that the light fell on but it
did not light 'around' objects in the same way that the previous flood
did. I think a lot of that is to do with the fact that the halogen
lamp worked properly in that the source was in front of the reflector
and the light was distributed: despite having what looks like a
reflector, the LEDs being behind the reflector do not actually 'use'
the reflector and thus works like a point source. Even though street
lights have a number of these point sources they still don't spread
the light in the same way and that is why I personally find them
unacceptable.

I have a R7s 118mm fitting at the front of the house in which I
replaced the halogen with a LED assembly of 6W rating. Whilst I do not
like the colour of the light emitted, as the source is in a similar
physical position to the tube that it replaced it uses the reflector
'properly' spreads the light in a much more visibly acceptable
pattern.


--
Woody

harrogate3 at ntlworld dot com


  #9  
Old January 1st 17, 03:41 PM posted to uk.tech.digital-tv
Jim Lesurf[_2_]
external usenet poster
 
Posts: 4,126
Default Do LED bulbs interfere with DAB radio?

In article , Max
Demian
wrote:

IEEE Spectrum did an article on this some time ago. One result of the
above is that many locations adopted the new LEDs for street lighting
to save power/money. They now realise those LEDs are uncomfortably
'blue' and need replacing.


Why does it matter with street lights? No-one (effectively) complained
about the (bluish) mercury lights or even low (yellow) and high (pink)
pressure sodium lights.


Afraid I can't now recall the reasons given. I'll see if I can find my copy
of that issue of 'Spectrum', although I tend to bin them afer a few months
so this will be a matter of luck. Alteratively, the article may be on their
website.

Jim

--
Please use the address on the audiomisc page if you wish to email me.
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html
Audio Misc http://www.audiomisc.co.uk/index.html

 




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