sort-of OT: interference to remote-control systems from fluo

[William Sommerwerck]

Just out of curiosity -- does anyone know how common it is for the IR from
fluorescent lighting to interfere with remote-control systems?

I've seen this with a Sony VCR. And the Vizio TV in my den shut off twice this
morning. * (This happens several times a week.)

* No, the sleep timer is not engaged.


"We already know the answers -- we just haven't asked the right questions."
-- Edwin Land

 

[Paul Drahn]

On 9/14/2013 5:03 AM, William Sommerwerck wrote:

Just out of curiosity -- does anyone know how common it is for the IR
from fluorescent lighting to interfere with remote-control systems?

I've seen this with a Sony VCR. And the Vizio TV in my den shut off
twice this morning. * (This happens several times a week.)

* No, the sleep timer is not engaged.


"We already know the answers -- we just haven't asked the right questions."
-- Edwin Land

I guess I will go out on a limb and say the fluorescent lighting emits
every little IR. Some of the UV from the mercury vapor arc will get
through the phosphor. Any IR will come from the heating of the glass tube.

Also, the IR would have to match the coded signal that tells the VCR and
TV to turn off. Any IR from the light would be steady. The UV would
fluctuate 120 times per second.

Pretty slim chance of all that coming together at one time to tell the
equipment to shut off.

Paul

 

[William Sommerwerck]

"Paul Drahn" wrote in message news:l11pi6$ul8$1@dont-email.me...

I guess I will go out on a limb and say the fluorescent lighting emits very
little IR. Some of the UV from the mercury vapor arc will get through the
phosphor. Any IR will come from the heating of the glass tube.

Also, the IR would have to match the coded signal that tells the VCR and TV
to turn off. Any IR from the light would be steady. The UV would fluctuate
120 times per second.

Pretty slim chance of all that coming together at one time to tell the
equipment to shut off.

Agreed. But it happens. I first observed it with a conventional fluorescent
tube.

http://www.telegraph.co.uk/technology/7579181/Energy-saving-light-bulbs-can-interfere-with-television-sets.html

http://www.emsd.gov.hk/emsd/e_download/pee/infrared_interference_emsdweb.pdf

 

[Jeff Liebermann]

On Sat, 14 Sep 2013 05:03:58 -0700, "William Sommerwerck"
<grizzledgeezer@comcast.net> wrote:

Just out of curiosity -- does anyone know how common it is for the IR from
fluorescent lighting to interfere with remote-control systems?

I've seen this with a Sony VCR. And the Vizio TV in my den shut off twice this
morning. * (This happens several times a week.)

* No, the sleep timer is not engaged.

It's the electronic ballasts and switchers that run the fluorescent
lights that are the culprit. Most IR remotes use a 38KHz carrier
frequency. They can also be 33-40 or 50-60 KHz but those are
uncommon. CCFL lights run between 40-70 KHz. If the frequencies
match, you get interference problems.

Oddly, it's not false activation that causes the most complaints. It's
the failure to detect a proper signal from the remote that's more
common. Put a CCFL light near the TV and try using the remote. You
may find that you have to press the buttons a few times in order to
get a response, and that the remote range will be impacted. Turn off
the CCFL light, and the problem goes away.

Also, plasma TV's belch plenty of IR and various switching frequencies
which can affect IR remote receivers.
<www.avsforum.com/t/1082190/comcast-says-tv-interfering-w-cable-box-backlight-interferes-w-remote>
As an added bonus, plasma TV's also belch quite a bit of RFI/EMI,
which affects RF remote controls. These are often mistaken as IR
interference as some remotes will do both IR and RF.





--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[N_Cook]

On 14/09/2013 13:03, William Sommerwerck wrote:

Just out of curiosity -- does anyone know how common it is for the IR
from fluorescent lighting to interfere with remote-control systems?

I've seen this with a Sony VCR. And the Vizio TV in my den shut off
twice this morning. * (This happens several times a week.)

* No, the sleep timer is not engaged.


"We already know the answers -- we just haven't asked the right questions."
-- Edwin Land

Aiwa AD 6900 susceptible, a small shroud over the sensor, stopping lamp
light from the ceiling direction, stopped the interference

 

[Phil Hobbs]

On 09/14/2013 08:03 AM, William Sommerwerck wrote:

Just out of curiosity -- does anyone know how common it is for the IR
from fluorescent lighting to interfere with remote-control systems?

I've seen this with a Sony VCR. And the Vizio TV in my den shut off
twice this morning. * (This happens several times a week.)

* No, the sleep timer is not engaged.


"We already know the answers -- we just haven't asked the right questions."
-- Edwin Land

Electronic ballasts are evil for that, on account of their more or less
unfiltered 40 kHz switching action. They put out crap that extends out
way past 1 MHz.

Try magnetic ballasts if you can. (You can't with CFLs, of course.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

It may well be that flourescents put out very ittle IR, but what of the selectivity of the detector ? If the mix of the plastic isn't just right it could admit too much UV or even visible and pick it up as interference.

Of course the odds of it actually hitting a pulse train for a specific function are pretty tall, in fact it may be like hitting the lottery but it its playing maybe 30,000 tickets per second.

 

[hrhofmann@sbcglobal.net]

On Saturday, September 14, 2013 7:03:58 AM UTC-5, William Sommerwerck wrote:
> Just out of curiosity -- does anyone know how common it is for the IR from fluorescent lighting to interfere with remote-control systems? I've seen this with a Sony VCR. And the Vizio TV in my den shut off twice this morning. * (This happens several times a week.) * No, the sleep timer is not engaged. "We already know the answers -- we just haven't asked the right questions." -- Edwin Land

I have seen this a number of times, just turned off the offending light to use the remote.

 

[N_Cook]

On 16/09/2013 11:22, jurb6006@gmail.com wrote:

It may well be that flourescents put out very ittle IR, but what of the selectivity of the detector ? If the mix of the plastic isn't just right it could admit too much UV or even visible and pick it up as interference.

Of course the odds of it actually hitting a pulse train for a specific function are pretty tall, in fact it may be like hitting the lottery but it its playing maybe 30,000 tickets per second.

My only experience of this was the flourescent light would lock out any
r/c use , not erroneous code interpretation. Much like those continuous
50KHz IR jammers for people who object to others having control over the
zapper or pranks

 

[Cydrome Leader]

Paul Drahn <pdrahn@webformixair.com> wrote:

On 9/14/2013 5:03 AM, William Sommerwerck wrote:
Just out of curiosity -- does anyone know how common it is for the IR
from fluorescent lighting to interfere with remote-control systems?

I've seen this with a Sony VCR. And the Vizio TV in my den shut off
twice this morning. * (This happens several times a week.)

* No, the sleep timer is not engaged.


"We already know the answers -- we just haven't asked the right questions."
-- Edwin Land
I guess I will go out on a limb and say the fluorescent lighting emits
every little IR. Some of the UV from the mercury vapor arc will get
through the phosphor. Any IR will come from the heating of the glass tube.

Also, the IR would have to match the coded signal that tells the VCR and
TV to turn off. Any IR from the light would be steady. The UV would
fluctuate 120 times per second.

Pretty slim chance of all that coming together at one time to tell the
equipment to shut off.

Don't discount this.

I recently asked a Xeror repair man to share one of the biggest head
scratchers with me.

It was CFL or some type of discharge lighting in an office confusing the
IR paper path sensors in one of those copier/scanner/do everything beasts.
It caused the scanner paper feeder to fault, ever after it was replaced.

Repositioning the machine was the fix.

 

[William Sommerwerck]

"Cydrome Leader" wrote in message news:l17jud$i07$2@reader1.panix.com...

Also, the IR would have to match the coded signal that tells the VCR and
TV to turn off. Any IR from the light would be steady. The UV would
fluctuate 120 times per second.

Pretty slim chance of all that coming together at one time to tell the
equipment to shut off.

Don't discount this.

I recently asked a Xeror repair man to share one of the biggest head
scratchers with me.

It was CFL or some type of discharge lighting in an office confusing the
IR paper path sensors in one of those copier/scanner/do everything beasts.
It caused the scanner paper feeder to fault, ever after it was replaced.

Repositioning the machine was the fix.

As the OP, I need to clarify is that this is /exactly/ what I experienced --
/not/ interference preventing my remote-control transmitter from operating,
but the fluorescent light sending junk that the TV or VCR interpreted as a
valid command.

This happened to me not only with CFLs, but a GE LightStick.

 

[amdx]

On 9/14/2013 7:03 AM, William Sommerwerck wrote:

Just out of curiosity -- does anyone know how common it is for the IR
from fluorescent lighting to interfere with remote-control systems?

I've seen this with a Sony VCR. And the Vizio TV in my den shut off
twice this morning. * (This happens several times a week.)

* No, the sleep timer is not engaged.


"We already know the answers -- we just haven't asked the right questions."
-- Edwin Land

About 25 years ago, within a week of reading an article about
fluorescent bulbs overdriving the sensor of remote control devices,
I got a call. The remote for vcr had been in for repair, complaint
"does not work". I tested it and it worked properly. I was on the phone
with the customer and a bit perplexed, out of the blue I ask if had
changed any lighting, he said yes, they had put in a fluorescent light.
I ask him to shut it off, he did and the remote worked. I ask him if he
put a book on the VCR would that shield the light from the vcr receiver.
He tested it and that solved his problem. (yes light back on)
Mikek

 

[dave]

On 09/15/2013 11:59 AM, Phil Hobbs wrote:

On 09/14/2013 08:03 AM, William Sommerwerck wrote:
Just out of curiosity -- does anyone know how common it is for the IR
from fluorescent lighting to interfere with remote-control systems?

I've seen this with a Sony VCR. And the Vizio TV in my den shut off
twice this morning. * (This happens several times a week.)

* No, the sleep timer is not engaged.


"We already know the answers -- we just haven't asked the right
questions."
-- Edwin Land

Electronic ballasts are evil for that, on account of their more or less
unfiltered 40 kHz switching action. They put out crap that extends out
way past 1 MHz.

Try magnetic ballasts if you can. (You can't with CFLs, of course.)

Cheers

Phil Hobbs

What do RF emissions have to do with an infrared problem? Sunlight
reflecting on something shiny, or directly shining on the IR receiver,
will mess with the remote functions.

 

[David Platt]

In article <arSdnWPAC_GGyqXPnZ2dnUVZ_qmdnZ2d@earthlink.com>,
dave <dave@dave.dave> wrote:

Electronic ballasts are evil for that, on account of their more or less
unfiltered 40 kHz switching action. They put out crap that extends out
way past 1 MHz.

Try magnetic ballasts if you can. (You can't with CFLs, of course.)

What do RF emissions have to do with an infrared problem? Sunlight
reflecting on something shiny, or directly shining on the IR receiver,
will mess with the remote functions.

It's not an RF problem specifically.

The electronic ballasts operate at a high switching frequency, and
this causes the fluorescent tubes to flicker at this frequency. Some
of the tube output is IR.

TV remote controls operate via pulse-modulated IR. The pulse
frequency is commonly in the 32 kHz - 40 kHz range. The IR receiver
commonly has a bandpass filter after the photodiode/amplifier, in
order to pass the correct frequency range and block out the effect of
sunlight and low-frequency (e.g. 60 Hz) IR noise.

If a fluorescent light using an electronic ballast is "within view" of
the TV remote's IR sensor, and if its switching frequency (and the
tube flickering) is within the frequency passband of the IR receiver,
then the IR receiver circuit will "see" the tube's output as a strong
signal of pulses. If strong enough, it will interfere with the
detection of the remote control's IR pulse sequence (which is in the
same passband).

 

[dave]

On 09/17/2013 10:42 AM, David Platt wrote:

In article <arSdnWPAC_GGyqXPnZ2dnUVZ_qmdnZ2d@earthlink.com>,
dave <dave@dave.dave> wrote:

Electronic ballasts are evil for that, on account of their more or less
unfiltered 40 kHz switching action. They put out crap that extends out
way past 1 MHz.

Try magnetic ballasts if you can. (You can't with CFLs, of course.)

What do RF emissions have to do with an infrared problem? Sunlight
reflecting on something shiny, or directly shining on the IR receiver,
will mess with the remote functions.

It's not an RF problem specifically.

The electronic ballasts operate at a high switching frequency, and
this causes the fluorescent tubes to flicker at this frequency. Some
of the tube output is IR.

TV remote controls operate via pulse-modulated IR. The pulse
frequency is commonly in the 32 kHz - 40 kHz range. The IR receiver
commonly has a bandpass filter after the photodiode/amplifier, in
order to pass the correct frequency range and block out the effect of
sunlight and low-frequency (e.g. 60 Hz) IR noise.

If a fluorescent light using an electronic ballast is "within view" of
the TV remote's IR sensor, and if its switching frequency (and the
tube flickering) is within the frequency passband of the IR receiver,
then the IR receiver circuit will "see" the tube's output as a strong
signal of pulses. If strong enough, it will interfere with the
detection of the remote control's IR pulse sequence (which is in the
same passband).

I would think the persistence of the fluorescing medium would make an RF
excitation invisible.

 

[hrhofmann@sbcglobal.net]

Take a small am portable radio and sniff around a fluorescent light fixture with a magnetic ballast, and then do the same thing in the area around any cfl which haall have electronic ballasts, or around a regular fluorescent fixture that has an electronic ballast. See which type of ballast generates noise up into the AM MHz frequency band.

 

[Phil Hobbs]

On 09/19/2013 10:33 AM, dave wrote:

On 09/17/2013 10:42 AM, David Platt wrote:
In article <arSdnWPAC_GGyqXPnZ2dnUVZ_qmdnZ2d@earthlink.com>,
dave <dave@dave.dave> wrote:

Electronic ballasts are evil for that, on account of their more or less
unfiltered 40 kHz switching action. They put out crap that extends out
way past 1 MHz.

Try magnetic ballasts if you can. (You can't with CFLs, of course.)

What do RF emissions have to do with an infrared problem? Sunlight
reflecting on something shiny, or directly shining on the IR receiver,
will mess with the remote functions.

It's not an RF problem specifically.

The electronic ballasts operate at a high switching frequency, and
this causes the fluorescent tubes to flicker at this frequency. Some
of the tube output is IR.

TV remote controls operate via pulse-modulated IR. The pulse
frequency is commonly in the 32 kHz - 40 kHz range. The IR receiver
commonly has a bandpass filter after the photodiode/amplifier, in
order to pass the correct frequency range and block out the effect of
sunlight and low-frequency (e.g. 60 Hz) IR noise.

If a fluorescent light using an electronic ballast is "within view" of
the TV remote's IR sensor, and if its switching frequency (and the
tube flickering) is within the frequency passband of the IR receiver,
then the IR receiver circuit will "see" the tube's output as a strong
signal of pulses. If strong enough, it will interfere with the
detection of the remote control's IR pulse sequence (which is in the
same passband).



I would think the persistence of the fluorescing medium would make an RF
excitation invisible.

It pretty well does, except in the closely-spaced emission lines, which
respond fast, especially near the ends of the tubes. You can get
annoying amounts of crap out past 1.5 MHz, even with carefully chosen
interference filters.

See e.g.
<http://electrooptical.net/www/optics/VishayFluorescentLightDisturbanceAppNote.pdf>
and
<http://electrooptical.net/www/optics/FluorescentSpursIEEE1996ir.pdf>

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net

 

"It pretty well does, except in the closely-spaced emission lines, which
respond fast, especially near the ends of the tubes. You can get......"

I was thinking along similar lines sorta....

The IR might not really come from the phosphors so much as rom the arc itself. Unless the glass or something filters it there should be some output in those ranges.

 

[Michael A. Terrell]

Phil Hobbs wrote:

It pretty well does, except in the closely-spaced emission lines, which
respond fast, especially near the ends of the tubes. You can get
annoying amounts of crap out past 1.5 MHz, even with carefully chosen
interference filters.

Phil, a fluorescent lamp puts out noise well past 4 GHz. I used to
use one on the bench to test C-band LNAs and LNBs. Noise sources use gas
discharge tubes to produce broadband noise.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

 

[Phil Hobbs]

On 09/27/2013 03:59 PM, Michael A. Terrell wrote:

Phil Hobbs wrote:

It pretty well does, except in the closely-spaced emission lines, which
respond fast, especially near the ends of the tubes. You can get
annoying amounts of crap out past 1.5 MHz, even with carefully chosen
interference filters.


Phil, a fluorescent lamp puts out noise well past 4 GHz. I used to
use one on the bench to test C-band LNAs and LNBs. Noise sources use gas
discharge tubes to produce broadband noise.

That's the blackbody noise of the plasma, though, which is a lot lower
than the radiated harmonics of the switching frequency. (Besides, at
300K the blackbody peak is at around 18 THz.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net