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Interference from household LED lamps

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Posted by danno54 on Saturday, March 23, 2019 8:21 AM

Yes, the early and cheaper leds do create an interference. I install two on my garage door opener a few years ago. My remote would not operate the door when the lights were on. Door would open from the street but would not close with the remote till lights went off. Took me about a week to figure this out. Went to the door manufacturers website where they list compatible led lights. Most new name brand leds will work now.

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Posted by rrinker on Friday, March 22, 2019 9:36 PM

dbduck

LED lamps that utilize mains voltage require a means of converting the relatively-high AC voltage into a DC current for the LEDs. To do this efficiently, the mains voltage is usually rectified into high voltage DC, filtered, and then switched off and on rapidly (“chopped”) with an oscillator running at a high frequency. The on-time of the waveform is modulated to supply a specific average current to the LEDs. Some of the energy in the high-frequency chopping circuit emanates in the form of an electromagnetic field (“broadcasts”), and some is conducted back into the mains circuit. The broadcast and conducted energy may be detected in nearby electronic devices, and represents interference.

The cheaper the componants used ..the more interference possible

 

 There are very few that actually utilize a switch mode power supply liek that. Maybe strips, where you have a separate power supply. But n the bulbs? Probably 90% are simple capacitor droppers.

 The ones that would be skirting FCC rules on RF emission interference would also be the ones too cheap to use a switching supply that actually might generate interferences up at 2.4GHz, they'd just have even crappier capacitor droppers (while in the UK, it's still relevent - check out Big Clive on YouTube, he's forever tearing apart various LED lights and once getting the guts out is rarely surprised by anything but a capacitor dropper). 

 And it would have to be a very poor switchmode supply - considering my wireless AP is surrounded by two computers, both equipped naturally with switch mode power supplies. The do not interrupt the wifi signal in my house. They would, as Greg mentioned, be breaking the law selling power supplies that did so - in the US for sure and most other countries have rules similar to FCC part 15. 

                                                      --Randy

 


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by RR_Mel on Friday, March 22, 2019 9:35 AM

I checked my LED lighting with a spectrum analyzer and I didn’t find any RF noise at all.  I checked the line voltage with a scope and it is also quiet, well normal for AC lines.
 
I turned the LEDs on and off several times looking for anything and I couldn’t see anything.
 
My Fluorescent replacement LEDs are Hyperikon, a few screw in Feit, GE, Philips and Cree Floods.  I removed all of the Ballasts from the fixtures, all of my Fluorescent replacements are wired direct to line.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by dbduck on Friday, March 22, 2019 8:42 AM

LED lamps that utilize mains voltage require a means of converting the relatively-high AC voltage into a DC current for the LEDs. To do this efficiently, the mains voltage is usually rectified into high voltage DC, filtered, and then switched off and on rapidly (“chopped”) with an oscillator running at a high frequency. The on-time of the waveform is modulated to supply a specific average current to the LEDs. Some of the energy in the high-frequency chopping circuit emanates in the form of an electromagnetic field (“broadcasts”), and some is conducted back into the mains circuit. The broadcast and conducted energy may be detected in nearby electronic devices, and represents interference.

The cheaper the componants used ..the more interference possible

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Posted by SouthPenn on Sunday, March 17, 2019 11:50 AM

I have an NCE Power Pro and a RailPro system for my layout. I changed to LEDs about a year ago. I haven't had any problems. But the lamps were bought through the power company and are not dimmable. ( 65W equivalent flood lamps ). 

South Penn
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Posted by gregc on Sunday, March 17, 2019 10:00 AM

why does anyone think LEDs generate interference at RF frequencies?

almost all devices must not generate inteference above some power level at RF frequencies.

greg - Philadelphia & Reading / Reading

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Posted by RR_Mel on Saturday, March 16, 2019 6:02 AM

The last time I checked my house with a spectrum analyzer it scared me. There is noise every where, everyone within a mile of my house must have all kinds of wireless stuff.  Some pretty powerful too, stronger than my router.  The grass is almost as high as my router.
 
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by rrinker on Friday, March 15, 2019 11:40 PM

 The cheapest LED bulbs use an absolute cheap, crappy capacitor dropper circuit to reduce the 120VAC to somethign the LEDs can use (not all the way down to 3.5 volts, most LED bulbs have strings of LEDs in series so the voltage doesn't have to be dropped as much - which just wastes energy). These circuits are 'noisy' electrically, but I'm kind of amazed that they would have strong enough harmonics at 2.4GHz to disrupt the radio communications. Guess I need to get a spectrum analyzer now and check out my LEDs - I have ones that have been in place 5 years now. 

                                            --Randy


Modeling the Reading Railroad in the 1950's

 

Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.

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Posted by dbduck on Wednesday, March 13, 2019 2:18 PM

Changing the brand of LEDs in the garage has fixed that issue

went from a cheaper brand to a made in the USA brand

hope this is not in violation of forum but it was recommended to me to purchase Ace Hardware brand non dimmable lamps

Also Genie sells LEDs specifically for openers

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Posted by gmpullman on Wednesday, March 13, 2019 1:48 PM

Household Lambs? That could be a problem! I was infested with goats, once Sad

My Digitrax wireless has been in use for fifteen years or more. I converted from the 916.5 Mhz to the 2.4 Ghz duplex maybe five years ago. My layout room is full of various LED lamps and drivers from tiny 0406 LEDs on the layout to 2' x 4' lay in, edge-lighted troffers in the ceiling.

Go here and you will find many hints for improving Digitrax wireless operation:

http://www.digitrax.com/tsd/

 

I don't believe there is any interference with the Digitrax throttle reception caused by the LEDs.

The mass of my body, large metal objects like a freezer, washing machine or the wire-screen I used under some of my hardshell scenery does contribute to an interrupted signal.

Be sure your throttle and UR92 have been updated with the most recent firmware.

http://www.digitrax.com/downloads/

 

Be sure your UR92 is mounted high enough to get a clear signal. Someone suggested mounting the "ground-plane" of the UR92 upside down in order to improve reception. Maybe that helped, maybe not.

You can also try different channels and see if one works better than the other.



dbduck
I started having issues with my door opener remotes...but only closing & when light was on...
 

Does your garage door operator have an IR sensor across the doorway? I have found that stray light, possibly the waveform from an LED, will cause the IR safety-beam to misbehave. Be sure they are aimed perfectly. You may have to shade the reciever from the garage LEDs.

My overhead door faces west and at certain times of the evening the sunlight would interfere with the IR beam. Careful aiming mitigated this problem.

Good Luck, Ed

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Posted by gregc on Wednesday, March 13, 2019 11:58 AM

it looks like both the NCE and Digitrax wireless systems operate on the ISM band at 916 MHz.

the Pacific Southern club has an interference problem.   I borrowed a spectrum analyzer from work and we were surprised to see an signal at 916 MHz every so often and lasting for many (> 10) seconds.    We never identified the source of the interference.

The ISM band is not licensed.  So other devices can operate on it.

greg - Philadelphia & Reading / Reading

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Posted by RR_Mel on Wednesday, March 13, 2019 11:44 AM

I don’t use wireless DCC but I do have all kinds of wireless devices and I don’t have any problems from my LED lighting.  I cutover to LED lighting last summer and all of the LED drivers are inside the bulbs.  So if your LEDs are like mine removing the bulbs should remove any interference.
 
The only time I have had a radiation problem from a light fixture was replacing a transformer type ballast with an electronic ballast.
 
Light dimmers can radiate some RF noise.  The only thing in our house that dings any of our wireless goodies is the Kitchen Microwave and it only radiates a few feet (roughly 3’ max).
 
 
EDIT:
 
Might help if you edit the topic and replace the typo.
 
Mel
 
 
My Model Railroad   
 
Bakersfield, California
 
I'm beginning to realize that aging is not for wimps.
 
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Posted by Water Level Route on Wednesday, March 13, 2019 11:15 AM

FWIW, when I started my current layout four years ago, I immediately installed lesser expensive LED bulbs and purchased an NCE wireless set-up.  Never had any issues.

Mike

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Interference from household LED lamps
Posted by dbduck on Wednesday, March 13, 2019 10:37 AM

Has anyone experienced any issue  with their radio throttles caused by interferrence from LED lamps. I am experiencing  issues with my Digitrax 400R throttle & thought maybe its because of me recently changing  all the lamps in my basement to LEDs

Through experimenting (removing all the lamps) I have found that it hasnt fixed the issue, so I guess I will be contacting Digitrax customer service for more help

The reason I suspected it could be was that  is  that at the same time  I change to LEDs in the basement I changed the lamps in the garage as well..I started having issues with my door opener remotes...but only closing & when light was on...never when coming home after the door had been closed for awhile. After doing some reseach I found that LEDS, esp lesser expensive ones that have less shielding around the lamp driver, can cause RF interferrence. After talking to a garage door installer at a recent Home Improvement Show he recommended a brand of lamp that would work (and has) for the garage

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