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Noise from LEDs

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johnpierce

Noise from LEDs

My kitchen, under cabinet lights, are LEDs. With those lights turned on my
noise floor changes from -128db to -102db. If the circuit is changed to a
different phase the noise improves by 6db. All of this at 7mhz and other
higher bands. Needless to say the AM broadcast band is highly affected by
the LEDs.

Placing a type 31 core with three turn of the AC line feeding the LED power
supply and a clamp on 31 core on the LED side of the power supply provides
no improvement! I do not have an oscilloscope to look at the waveforms.
But given what I have done, why is there no improvement? I was following
recommendations provided by NK7Z.

AD2F, John

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Jim Brown-10

Re: Noise from LEDs

On Mon,2/1/2016 7:48 PM, johnpierce wrote:
> Placing a type 31 core with three turn of the AC line feeding the LED power
> supply and a clamp on 31 core on the LED side of the power supply provides
> no improvement! I do not have an oscilloscope to look at the waveforms.
> But given what I have done, why is there no improvement?

You don't have nearly enough turns. Study k9yc.com/RFI-Ham.pdf

But -- a FAR better solution is to replace the power supply, which is
almost certainly a switching p/s, with a linear supply have the same
voltage and current ratings.

73, Jim K9YC
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Matthew Cook

Re: Noise from LEDs

In reply to this post by johnpierce

John,

That tells you that the noise from the LED power supply is differential
noise and not common mode. You might find this URL helpful, just focus on
the pictures on the first page.

http://www.murata.com/~/media/webrenewal/products/emc/emifil/knowhow/26to30.ashx

Figuring out what type of noise you're dealing with is the first step to
reducing it. You might find it easier to replace the LED driver you're
using with another unit and see if you get an improvement.

73

Matthew
VK5ZM

On 2 February 2016 at 14:18, johnpierce <[hidden email]> wrote:

> My kitchen, under cabinet lights, are LEDs. With those lights turned on my
> noise floor changes from -128db to -102db. If the circuit is changed to a
> different phase the noise improves by 6db. All of this at 7mhz and other
> higher bands. Needless to say the AM broadcast band is highly affected by
> the LEDs.
>
>
>
> Placing a type 31 core with three turn of the AC line feeding the LED power
> supply and a clamp on 31 core on the LED side of the power supply provides
> no improvement! I do not have an oscilloscope to look at the waveforms.
> But given what I have done, why is there no improvement? I was following
> recommendations provided by NK7Z.
>
>
>
> AD2F, John
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
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> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

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Bob McGraw - K4TAX

Re: Noise from LEDs

In reply to this post by johnpierce

As Dave, NK7Z stated in part 2: "If I have a RF generating wall wart,
it is best to remove it and replace it with one that does not generate
RFI, not just put ferrite material on it."

From this and your description, I would speculate the power supply is
the guilty party that is creating the RFI and it should be replaced.
Case and point, I went through three different chargers for my HP laptop
before I found one that didn't create RFI issues. And note too, they
were all "certified" according to the labeling on their cases.

73
Bob, K4TAX

On 2/1/2016 9:48 PM, johnpierce wrote:

Robert Nobis - N7RJN

Re: Noise from LEDs

In reply to this post by johnpierce

Hi John,

Possibly the undercounted LEDs or their power supply are defective and should be replaced. I have about 30 LED light bulbs of various types in my house and I have not experienced any issues with an increase in the noise floor.

73,

Bob Nobis - N7RJN
[hidden email]

> On Feb 1, 2016, at 20:48, johnpierce <[hidden email]> wrote:
>
> My kitchen, under cabinet lights, are LEDs. With those lights turned on my
> noise floor changes from -128db to -102db. If the circuit is changed to a
> different phase the noise improves by 6db. All of this at 7mhz and other
> higher bands. Needless to say the AM broadcast band is highly affected by
> the LEDs.
>
>
>
> Placing a type 31 core with three turn of the AC line feeding the LED power
> supply and a clamp on 31 core on the LED side of the power supply provides
> no improvement! I do not have an oscilloscope to look at the waveforms.
> But given what I have done, why is there no improvement? I was following
> recommendations provided by NK7Z.
>
>
>
> AD2F, John
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

NK7Z

Re: Noise from LEDs

In reply to this post by johnpierce

Hi,
Jim is correct, replace it... I had a neighbor, and I had several
ferrites on it, all with many many turns of cable, and got very little
positive result, replacing it gave me a positive result... :)

Those things generate a horrendous amount of RFI, and the power cables
to the lights are nothing but antenna... Consider how much reduction
you will need to get to your original noise floor. If you must keep
the PS, then more turns is better. Replacement is always preferable to
reduction techniques.
--
73's, and thanks,
Dave

For software/hardware reviews see:
http://www.nk7z.net

For MixW support see:
https://groups.yahoo.com/neo/groups/mixw/info

For SSTV help see:
http://groups.yahoo.com/neo/groups/MM-SSTV/info

On Mon, 2016-02-01 at 22:48 -0500, johnpierce wrote:

> My kitchen, under cabinet lights, are LEDs.  With those lights turned
> on my
> noise floor changes from -128db to -102db.  If the circuit is changed
> to a
> different phase the noise improves by 6db.  All of this at 7mhz and
> other
> higher bands.  Needless to say the AM broadcast band is highly
> affected by
> the LEDs.
>
>
>
> Placing a type 31 core with three turn of the AC line feeding the LED
> power
> supply and a clamp on 31 core on the LED side of the power supply
> provides
> no improvement!  I do not have an oscilloscope to look at the
> waveforms.
> But given what I have done, why is there no improvement?  I was
> following
> recommendations provided by NK7Z.
>
>
>
> AD2F,  John
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

Jim Sheldon

Re: Noise from LEDs

In reply to this post by johnpierce

I don't usually chime in on these threads, but not all LED's are
culprits. I had originally replaced all the incandescent bulbs in my
house with the compact fluorescent (CFL) type. My noise floor went up a
couple of dB when any of them were on, so after a couple of those so
called "5000 hour" Chinese CFL's actually burned up (yes, smoke, fire
and flames) I bit the bullet and replaced all the fluorescent lights in
the house with LED's, including some ceiling fixtures that used 2 and 4
foot tubes. Even though I don't have any "light dimmers" in the house,
I bought the "dimmable" LED 60 and 75 watt equivalents and now my noise
when they on is exactly the same as when they are all off. Getting rid
of the CFL's and doing to the LED's dropped my noise floor to whatever
the atmospheric (plus whatever the neighbors generate) noise floor is.

Sure glad those CFL's tried to burn down my house as it caused me to get
rid of them. I was able to hear and work the South Georgia VP8SGI
station on 15 meters and he was only maybe S1 here. Bad propagation to
that part of the world from Kansas even with 500 watts and a beam so I
missed the South Sandwich part. Never heard them except on 30 meters
and my antenna favors East/West and I swear some of the people that
worked them on 30 were so strong here that HAD to be using more than the
legal power limit on 30.

Jim - W0EB

>
>
>
>On Mon, 2016-02-01 at 22:48 -0500, johnpierce wrote:
>> My kitchen, under cabinet lights, are LEDs. With those lights turned
>> on my
>> noise floor changes from -128db to -102db. If the circuit is changed
>> to a
>> different phase the noise improves by 6db. All of this at 7mhz and
>> other
>> higher bands. Needless to say the AM broadcast band is highly
>> affected by
>> the LEDs.
>>
>>
>>
>> Placing a type 31 core with three turn of the AC line feeding the LED
>> power
>> supply and a clamp on 31 core on the LED side of the power supply
>> provides
>> no improvement! I do not have an oscilloscope to look at the
>> waveforms.
>> But given what I have done, why is there no improvement? I was
>> following
>> recommendations provided by NK7Z.
>>
>>

Bob McGraw - K4TAX

Re: Noise from LEDs

In reply to this post by NK7Z

Also, consider wrapping the PS in Aluminum Foil. That may provide some
degree of shielding.

On that point, I have two Direct TV receivers that were prone to
changing channels, resetting, and such when I transmitted. This was
proven to be the broad RF input for the RF remote control portion of the
receiver. No amount of ferrite on the cables helped. Even after they
were switched to IR Remote, no improvement. Finally I wrapped the
units in Aluminum Foil leaving a small 1/2" window for the IR remote
signal access. Problem solved.

73
Bob, K4TAX
K3S - sn 10163

On 2/2/2016 8:04 AM, Dave Cole wrote:

> Hi,
> Jim is correct, replace it... I had a neighbor, and I had several
> ferrites on it, all with many many turns of cable, and got very little
> positive result, replacing it gave me a positive result... :)
>
> Those things generate a horrendous amount of RFI, and the power cables
> to the lights are nothing but antenna... Consider how much reduction
> you will need to get to your original noise floor. If you must keep
> the PS, then more turns is better. Replacement is always preferable to
> reduction techniques.

Elecraft mailing list

Re: Noise from LEDs

In reply to this post by johnpierce

...and I'd add the cheap Chinese LED's are a serious issue.

Our garage door opener was randomly working during and after a recent
kitchen remodel.

After befriending Google, used the KX3 with a snoop loop, and found that
switching on either of 2 banks of new LED's generated enough RF to swamp the
garage door opener receiver about 15 feet away.

At least in our case the KX3 and loop did a good job of identifying which
LED fixtures were the offending culprits, but finding a listing of good vs.
bad brands remains difficult, if anyone has seen one would love to know...

73 Scott ka9p

In a message dated 2/2/2016 8:30:33 A.M. Central Standard Time,
[hidden email] writes:

I don't usually chime in on these threads, but not all LED's are
culprits. I had originally replaced all the incandescent bulbs in my
house with the compact fluorescent (CFL) type. My noise floor went up a
couple of dB when any of them were on, so after a couple of those so
called "5000 hour" Chinese CFL's actually burned up (yes, smoke, fire
and flames) I bit the bullet and replaced all the fluorescent lights in
the house with LED's, including some ceiling fixtures that used 2 and 4
foot tubes. Even though I don't have any "light dimmers" in the house,
I bought the "dimmable" LED 60 and 75 watt equivalents and now my noise
when they on is exactly the same as when they are all off. Getting rid
of the CFL's and doing to the LED's dropped my noise floor to whatever
the atmospheric (plus whatever the neighbors generate) noise floor is.

Sure glad those CFL's tried to burn down my house as it caused me to get
rid of them. I was able to hear and work the South Georgia VP8SGI
station on 15 meters and he was only maybe S1 here. Bad propagation to
that part of the world from Kansas even with 500 watts and a beam so I
missed the South Sandwich part. Never heard them except on 30 meters
and my antenna favors East/West and I swear some of the people that
worked them on 30 were so strong here that HAD to be using more than the
legal power limit on 30.

Jim - W0EB

---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus

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Robert Nobis - N7RJN

Re: Noise from LEDs

In reply to this post by Jim Sheldon

Ron,

I have had two CFL’s fail that were well beyond a “puff of smoke”. Both were actually melted and charred black. They were from two different manufacturers. I also have had CFL’s simply quit after a few years, and the base of them was brown from overheating.

That is part of the reason why I converted all bulbs in my house to LED.

73

Bob Nobis - N7RJN
[hidden email]

> On Feb 2, 2016, at 10:44, Ron D'Eau Claire <[hidden email]> wrote:
>
> That sounds like the CFL failed as it was designed to fail.
>
> CFLs draw more current as they age. Eventually the power supply is
> overwhelmed by the current demand and fails. All the CFLs I've seen use a
> tiny (1/8 or 1/16 watt) resistor as a fuse. Before anything else gets
> overloaded enough to fail, the little resistor acts as a fuse and opens.
> But, being a resistor, it fails like a resistor often with some smell and
> brief puff of smoke. I suppose it might be possible for a flame as the
> covering burns, but that should be inside the base enclosure. I've never
> seen anything but a small puff of smoke if I am looking in that direction
> when it goes.
>
> 73, Ron AC7AC
>
>
>
> -----Original Message-----
> ... a couple of those so called "5000 hour" Chinese CFL's actually burned up
> (yes, smoke, fire and flames)
>
> Jim - W0EB
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Bob N3MNT

Re: Noise from LEDs

It could actually be the LED modules themselves. Many of the cheap foreign LED modules use very cheap components in their drive circuitry. There are very RF noisy and cover a wide bandwidth, The RV industry switched to interior LED modules in the last few years and there have been loads of complaints of interference with radio and TV signals. If you have a linear power supply you can connect to drive the LEDS you can isolate the problem.

GM4JJJ

Re: Noise from LEDs

In reply to this post by Jim Sheldon

I was just thinking that I had removed all of the CFL bulbs from my house, because I hate them, their horrid colour, their slow start up and that they do not last and smoke. Then tonight my wife called me to say that the hall light had stopped working, the last CFL in the house. No smoke, just dead. It has hardly been used in the years we have had it.

I have replaced all my CFLs with Halogen clear bulbs (40 watts) which we can still get through some loophole, at least for now. I care not that they produce some heat as well as light, as it warms the house up who we have the lights on in the winter. I am stockpiling them.

I have LEDs in the bathroom that don't appear to cause any noise, ironically the 12 V halogen ones before did because of the SMPSU that they used.

I also have a Phillips LED lamp bulb in a table lamp that is totally RF quiet.

73 from David GM4JJJ

> On 2 Feb 2016, at 17:44, Ron D'Eau Claire <[hidden email]> wrote:
>
> That sounds like the CFL failed as it was designed to fail.
>
> CFLs draw more current as they age. Eventually the power supply is
> overwhelmed by the current demand and fails. All the CFLs I've seen use a
> tiny (1/8 or 1/16 watt) resistor as a fuse. Before anything else gets
> overloaded enough to fail, the little resistor acts as a fuse and opens.
> But, being a resistor, it fails like a resistor often with some smell and
> brief puff of smoke. I suppose it might be possible for a flame as the
> covering burns, but that should be inside the base enclosure. I've never
> seen anything but a small puff of smoke if I am looking in that direction
> when it goes.
>
> 73, Ron AC7AC
>
>
>
> -----Original Message-----
> ... a couple of those so called "5000 hour" Chinese CFL's actually burned up
> (yes, smoke, fire and flames)
>
> Jim - W0EB
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

wayne burdick

Re: Noise from LEDs

Administrator

In California, at least, consumers are converting from incandescents and CFLs to LEDs so quickly that planned new power plants will be unnecessary. This is a Good Thing. Home Depot has massive displays of LED bulbs, which are now down to around $3 per (in the FunSize 3-pack). IKEA is even cheaper.

I think everything in our house is now LED except for some candelabra-size 25-W bulbs in the dining room. My wife doesn't like the look of the LED replacements in this category, but eventually they, too will go. Then our electricity consumption due to lighting will be down by 84% for the entire house.

Edison would have been amazed to put his hand on a cool 10-W LED bulb that's putting our just as much light as a hot 60-W incandescent. Or maybe he would have been jealous.

Wayne
N6KR

On Feb 2, 2016, at 3:55 PM, David Anderson <[hidden email]> wrote:

> I was just thinking that I had removed all of the CFL bulbs from my house, because I hate them, their horrid colour, their slow start up and that they do not last and smoke. Then tonight my wife called me to say that the hall light had stopped working, the last CFL in the house. No smoke, just dead. It has hardly been used in the years we have had it.
>
> I have replaced all my CFLs with Halogen clear bulbs (40 watts) which we can still get through some loophole, at least for now. I care not that they produce some heat as well as light, as it warms the house up who we have the lights on in the winter. I am stockpiling them.
>
> I have LEDs in the bathroom that don't appear to cause any noise, ironically the 12 V halogen ones before did because of the SMPSU that they used.
>
> I also have a Phillips LED lamp bulb in a table lamp that is totally RF quiet.
>
> 73 from David GM4JJJ
>
>> On 2 Feb 2016, at 17:44, Ron D'Eau Claire <[hidden email]> wrote:
>>
>> That sounds like the CFL failed as it was designed to fail.
>>
>> CFLs draw more current as they age. Eventually the power supply is
>> overwhelmed by the current demand and fails. All the CFLs I've seen use a
>> tiny (1/8 or 1/16 watt) resistor as a fuse. Before anything else gets
>> overloaded enough to fail, the little resistor acts as a fuse and opens.
>> But, being a resistor, it fails like a resistor often with some smell and
>> brief puff of smoke. I suppose it might be possible for a flame as the
>> covering burns, but that should be inside the base enclosure. I've never
>> seen anything but a small puff of smoke if I am looking in that direction
>> when it goes.
>>
>> 73, Ron AC7AC

Guy Olinger K2AV

Re: Noise from LEDs

Jealous. Transported forward in time, he would have been like a kid in a
candy store in the midst of all our technology.

Guy K2AV

On Tue, Feb 2, 2016 at 7:03 PM, Wayne Burdick <[hidden email]> wrote:

> In California, at least, consumers are converting from incandescents and
> CFLs to LEDs so quickly that planned new power plants will be unnecessary.
> This is a Good Thing. Home Depot has massive displays of LED bulbs, which
> are now down to around $3 per (in the FunSize 3-pack). IKEA is even cheaper.
>
> I think everything in our house is now LED except for some candelabra-size
> 25-W bulbs in the dining room. My wife doesn't like the look of the LED
> replacements in this category, but eventually they, too will go. Then our
> electricity consumption due to lighting will be down by 84% for the entire
> house.
>
> Edison would have been amazed to put his hand on a cool 10-W LED bulb
> that's putting our just as much light as a hot 60-W incandescent. Or maybe
> he would have been jealous.
>
> Wayne
> N6KR
>
>
> On Feb 2, 2016, at 3:55 PM, David Anderson <[hidden email]> wrote:
>
> > I was just thinking that I had removed all of the CFL bulbs from my
> house, because I hate them, their horrid colour, their slow start up and
> that they do not last and smoke. Then tonight my wife called me to say that
> the hall light had stopped working, the last CFL in the house. No smoke,
> just dead. It has hardly been used in the years we have had it.
> >
> > I have replaced all my CFLs with Halogen clear bulbs (40 watts) which we
> can still get through some loophole, at least for now. I care not that they
> produce some heat as well as light, as it warms the house up who we have
> the lights on in the winter. I am stockpiling them.
> >
> > I have LEDs in the bathroom that don't appear to cause any noise,
> ironically the 12 V halogen ones before did because of the SMPSU that they
> used.
> >
> > I also have a Phillips LED lamp bulb in a table lamp that is totally RF
> quiet.
> >
> > 73 from David GM4JJJ
> >
> >> On 2 Feb 2016, at 17:44, Ron D'Eau Claire <[hidden email]> wrote:
> >>
> >> That sounds like the CFL failed as it was designed to fail.
> >>
> >> CFLs draw more current as they age. Eventually the power supply is
> >> overwhelmed by the current demand and fails. All the CFLs I've seen use
> a
> >> tiny (1/8 or 1/16 watt) resistor as a fuse. Before anything else gets
> >> overloaded enough to fail, the little resistor acts as a fuse and opens.
> >> But, being a resistor, it fails like a resistor often with some smell
> and
> >> brief puff of smoke. I suppose it might be possible for a flame as the
> >> covering burns, but that should be inside the base enclosure. I've never
> >> seen anything but a small puff of smoke if I am looking in that
> direction
> >> when it goes.
> >>
> >> 73, Ron AC7AC
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]
>

Eric Swartz - WA6HHQ

Re: Noise from LEDs

Administrator

And it looks like its time to close this thread. Wow, 17 posts in less than 22
hrs. Time to let others recover from the email overload.

In general, please self moderate in the future.

73,
Eric
List Moderator
/elecraft.com/

On 2/2/2016 4:30 PM, Guy Olinger K2AV wrote:

> Jealous. Transported forward in time, he would have been like a kid in a
> candy store in the midst of all our technology.
>
> Guy K2AV
>
> On Tue, Feb 2, 2016 at 7:03 PM, Wayne Burdick <[hidden email]> wrote:
>
>> In California, at least, consumers are converting from incandescents and
>> CFLs to LEDs so quickly that planned new power plants will be unnecessary.
>> This is a Good Thing. Home Depot has massive displays of LED bulbs, which
>> are now down to around $3 per (in the FunSize 3-pack). IKEA is even cheaper.
>>
>> I think everything in our house is now LED except for some candelabra-size
>> 25-W bulbs in the dining room. My wife doesn't like the look of the LED
>> replacements in this category, but eventually they, too will go. Then our
>> electricity consumption due to lighting will be down by 84% for the entire
>> house.
>>
>> Edison would have been amazed to put his hand on a cool 10-W LED bulb
>> that's putting our just as much light as a hot 60-W incandescent. Or maybe
>> he would have been jealous.
>>
>> Wayne
>> N6KR
>>
>>
>> On Feb 2, 2016, at 3:55 PM, David Anderson <[hidden email]> wrote:
>>
>>> I was just thinking that I had removed all of the CFL bulbs from my
>> house, because I hate them, their horrid colour, their slow start up and
>> that they do not last and smoke. Then tonight my wife called me to say that
>> the hall light had stopped working, the last CFL in the house. No smoke,
>> just dead. It has hardly been used in the years we have had it.
>>> I have replaced all my CFLs with Halogen clear bulbs (40 watts) which we
>> can still get through some loophole, at least for now. I care not that they
>> produce some heat as well as light, as it warms the house up who we have
>> the lights on in the winter. I am stockpiling them.
>>> I have LEDs in the bathroom that don't appear to cause any noise,
>> ironically the 12 V halogen ones before did because of the SMPSU that they
>> used.
>>> I also have a Phillips LED lamp bulb in a table lamp that is totally RF
>> quiet.
>>> 73 from David GM4JJJ
>>>
>>>> On 2 Feb 2016, at 17:44, Ron D'Eau Claire <[hidden email]> wrote:
>>>>
>>>> That sounds like the CFL failed as it was designed to fail.
>>>>
>>>> CFLs draw more current as they age. Eventually the power supply is
>>>> overwhelmed by the current demand and fails. All the CFLs I've seen use
>> a
>>>> tiny (1/8 or 1/16 watt) resistor as a fuse. Before anything else gets
>>>> overloaded enough to fail, the little resistor acts as a fuse and opens.
>>>> But, being a resistor, it fails like a resistor often with some smell
>> and
>>>> brief puff of smoke. I suppose it might be possible for a flame as the
>>>> covering burns, but that should be inside the base enclosure. I've never
>>>> seen anything but a small puff of smoke if I am looking in that
>> direction
>>>> when it goes.
>>>>
>>>> 73, Ron AC7AC
>>
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