LED light bulbs: an empirical observation

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Maxx

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I'm a cheap SOB.

Its only been very recently that prices on LED lightbulbs have come down to the point that I thought it worthwhile to start buying and using them. While I very much like the concept of a long life, low power consumption, cool running bulb, I discovered last night that there is a downside.

Also due to my cheap genes, I get TV via antenna rather than pay absurd amounts for cable or satellite. The last couple weeks, I've had unexplainable problems with Channel 2 (CBS here in Chicago) and 5 (NBC) has been shaky as well. If you know anything about broadcasting, you know that those channels are down in the low VHF band, and thus more subject to interference than the higher frequencies.

When I said unexplainable, I meant not the usual known problems. Channel 2 simply doesn't come in if Mrs. Maxx is playing her XBOX. Apparently they cut enough corners in design and components that it throws out spurious harmonics that disrupt the TV tuner on the low VHF channels. Driving a processor or power supply too hard can do that, and the XBOX does run pretty hot. Severe weather can do that as well. Weather has been bizarre recently, so I didn't look too hard for a cause.

Last night, though, Mrs. Maxx and I wanted to watch Hawaii 50, and Channel 2 was a pixel'd mess. Rotating the antenna didn't help. I got a new internet modem last week, so I tried turning that off to see if it was the problem. No change.

I was about to put it down to the neighbors getting some new, unknown, and malevolent RF generating device when the light bulb went on (pun intended) and I thought about the other electronic thing that had changed in the Maxx house.... a couple of LED bulbs in the man-cave track light. Went downstairs, turned that off, and Steve McGarret was good as gold.

Makes sense when you think about it.... cheap and dirty power supply in the lamp base to take the 120 VAC down to a usable DC voltage for the LED's. I don't have a scope, so I can't take one apart and look at the waveform, but I bet its filthy.

Funny when you think about it. All that AC infrastructure, and now a lot of our stuff is going back to DC. Edison vs. Westinghouse.
 
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starpup

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The cheaper led lights are dirty and unfortunately not worth it.
Ive never had a problem with the few globes i run in the house luckily, but i have helped friends install cheaper led light bars on their four wheel drives that when active totally ruin any am/fm radio reception and even render 27mhz and uhf c.b's completely useless.
Those light units removed and replaced with a decent quality one using the same wiring and switching then pose no problem.
 
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PaddedPuppy

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If you spend the extra cash on a decent LED bulb to start with, the savings will still be obvious over time, especially if you fully switch your home to LED. Dropping the power consumption to about a tenth of what the original lighting used, as well as the bulbs themselves being longer lasting, and giving a nice clean, bright light.

The cheap LED lights aren't even that much cheaper, but are so badly made and last for a much shorter length of time. Not only that but the circuit in the base is such bad quality that you can easily get such interference, overheating, sometimes leading to small explosions of the plastic/glass lighting globe and casing, and a few other more rare problems I heard of in the past. The LEDs themselves also are usually so cheap that some of them arrive dead, giving very uneven, and dimmer light.

From what you are saying, it sounds like the antenna is indoors beside the TV set. If at all possible, I would recommend getting a much better rooftop one, which will be better at picking up signals even if a little weak, and also potentially causing less interference troubles too.

Obviously I also suggest you ditch the poor lighting and invest in some of better quality, despite the higher cost
 
M

Maxx

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If you spend the extra cash on a decent LED bulb to start with, the savings will still be obvious over time, especially if you fully switch your home to LED. Dropping the power consumption to about a tenth of what the original lighting used, as well as the bulbs themselves being longer lasting, and giving a nice clean, bright light.

Thanks for the input, but....

Even incandescent bulbs don't use enough power to have much impact on the electric bill, unless you've got a huge house with a zillion lights that you leave on all the time. Refrigerator, AC, dryer, electric heaters, ie, anything with a motor or a heating element are the noticeable factors. Remember that I was paying electric bills when your parents were in diapers....

Its possible that some higher priced LED bulbs may produce less RFI .... but I haven't tested that myself. Until I have, its nothing but marketing blather as far as I'm concerned. All things electronic are made in the same factory in China. Brand hasn't meant diddly for at least 20 years. I don't know any sure way to know up front whether the $20 bulb is any different than the $2 one. Remember also that I started in the electronics manufacturing business when your parents were in diapers, and likely had my amateur radio license before they were born. I was present and involved when everything moved to Asia, and know how pricing and margin decisions are made.

From what you are saying, it sounds like the antenna is indoors beside the TV set. If at all possible, I would recommend getting a much better rooftop one, which will be better at picking up signals even if a little weak, and also potentially causing less interference troubles too.

Antenna is in the attic with an inline amplifier.... by calculated choice. I'm not really thrilled with the idea of going up on the roof every time a windstorm comes along to repair/replace the antenna and/or patch the roof, plus, I can rotate and aim the antenna for different stations via a broomstick through the access hatch. Granted, I'm in something of a fringe reception area, but it works fine unless I get really severe weather or Mrs. Maxx desperately needs to play XBOX during a Blackhawks playoff game. Then I go to Junior's, or one of us dies.

- - - Updated - - -

The cheaper led lights are dirty and unfortunately not worth it.
Ive never had a problem with the few globes i run in the house luckily, but i have helped friends install cheaper led light bars on their four wheel drives that when active totally ruin any am/fm radio reception and even render 27mhz and uhf c.b's completely useless.
Those light units removed and replaced with a decent quality one using the same wiring and switching then pose no problem.

Even if I was SURE that a given expensive LED bulb wouldn't put out RFI, I'd bypass that in favor of CFL or even incandescent. The payback just isn't there.

Edit: Call me quirky, but I've never been a big fan of a lot of bright lights, except right on my work surface, so maybe my lighting costs are atypical. ATM, the only lights down in the mancave are the 50 inch with Blackhawks v. Columbus, and the computer monitor.
 

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That is pretty interesting and not something I would have realized.

If you spend the extra cash on a decent LED bulb to start with, the savings will still be obvious over time, especially if you fully switch your home to LED. Dropping the power consumption to about a tenth of what the original lighting used, as well as the bulbs themselves being longer lasting, and giving a nice clean, bright light.

Ya as Maxx already pointed out, the savings you would see wouldn't be all that great even over time. I used to get in arguments with my step father about how much power my computer was using because he often would blame his expensive electric bill on my computer. I tried to explain to him that after I started living there, that the cause of the electric bill going up isn't due to the computer but because we started cooking more often rather then them eating out. Also, with an extra person using the washer and dryer. Basically I calculated based on the kW-h and the companies rates, and my computer running at full power would have only costed a max of like $10. A Computers power supply though does not run at full power non stop. Computers sit in idle most of the time. So the price would have only been closer to $2-3 each month.

Huge appliances consume a lot of energy and are always going to be the most noticeable factors in any household's electricity bill. People shut off light bulbs and honestly, it always makes me laugh because we are talking about change here.

I have never calculated the cost of replacing bulbs. So not sure if LED would be cheaper overall when you account for that, or if the extra cost of them negates their life span.
 

ade

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...I can't take one apart and look at the waveform, but I bet its filthy.

got to admit that my first thought was dodgy earthing, either of the AC supply or individual equpiment (http://www.svconline.com/news/news/understanding-and-controlling-rf-interference/364849), but another thing which can be filthy, or acting like it, are the contacts off and within devices; i've also found new type lightbulbs of the 'cost-effective' variety to be like this. i've even had to add solder to the contacts of some!

i'm just moving over the LED bulbs, from the false-efficient fluorescent compacts (mum and dad, as pensioners, got loads of free ones when they first came out), but i've not any issues. i only buy them out of the bargainbuckets, but try for known makes. it'd be interesting to look inside a few makes, for comparison, and to see how they're dropping and smoothing the power supply. surely they can't be scrimping there?
 

Cottontail

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...had my amateur radio license before they were born.

A hamateur? I had you pegged as the 11-meter type. ;->

I was present and involved when everything moved to Asia, and know how pricing and margin decisions are made.

Yeah... Hit one of those cheap drugstore USB phone chargers with a hammer and the problem is pretty obvious. Everything's gone low-voltage, so the market's been flooded with cheapo, non-shielded, switching-type power supplies. They spew harmonics like it's their primary function. And as with the dog-killing dogfood from China, there aren't enough regulatory personnel to check and certify the stuff. It gets rubber-stamped.

I've been accumulating GE-brand LED bulbs whenever they go on sale, and haven't had any RFI problems with those. My main gripe with them is the same as with most CFLs: They're butt-ass ugly. Even the nice new ones that have been color-balanced to produce a spectrum like incandescent bulbs still have a big white plastic base that takes up half their length. For light fixtures where you don't see the bulb, that's often fine. Otherwise, forget it!
 
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dogboy

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I think the bigger issue here is that Maxx and Mrs. Maxx were watching Hawaii 5 0!!! My wife likes the show and it's a good show for me hook her up to her dialysis machine. More on point, why was Lou Grover running in terror with his whole family when he has this incredible police force that single handedly brings down all of Afghanistan at least once a month, or some such country.

Then, once on the lamb with his family in tow, his slow mind realizes that his handlers are on the take, so he drives off into some rutted field after getting the idiots to crash their SUV into a tree, but even though they're on foot and he's driving, by running, they're keeping up with his SUV, shooting at him and his family. Then Lou, like a 90 year old grandmother, drives into a tree even though he's only doing about 15 miles an hour. The plot goes down hill from there. Who writes this stuff?

So yeah, The Washington Post had a big article today about LED bulbs and how much better they are than the old incandescent bulbs. The changeover was part of the 2007, George Bush energy plan. Still, the Post is in favor of the plan, but I guess getting quality bulbs sounds like the way to go.

In the past several years, I started replacing my bulbs with the fluorescent bulbs, but they put out a weak amount of light. I'm not sure if they create the same RF problems as I have to get my TV signal via Direct TV as we live surrounded by mountains.
 

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I switched to LED last year for pretty much everything except the downlights in the bathrooms, but they aren't on long enough to make a material impact on anything. I have to confess, my main motivation was improving the colour index over compact fluorescent, and getting instantaneous response, rather than the slow start-up of many warm-light CF bulbs. I haven't noticed any RF problems, but all my bulbs are Phillips models manufactured in France, so I suspect that the quality control is better.

The problem with arguing about savings is that you have to make a whole load of assumptions about utilisation, energy prices, discount rates and the cost of LED technology and potential competitors both now and in the future. There are savings to be made, but at this point, we are still in early adopter territory, and decent bulbs are still expensive enough that you have to restrict them to the main living areas - places where the lights are on continuously for hours every day - if you want to be sure of making savings.

Funny when you think about it. All that AC infrastructure, and now a lot of our stuff is going back to DC. Edison vs. Westinghouse.

Funny, but even if they'd known about the solid-state electronics revolution a century ago, the technology for long distance high-voltage DC transmission just didn't exist, and the efficiency advantages of large-scale AC generation and long-distance transmission were undeniable. Apart from anything else, I doubt that small-scale urban electricity generation using pre-war combustion technology would have survived the clean air movements. Edison may have the last laugh, but that doesn't mean that he was right at the time.
 
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M

Maxx

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got to admit that my first thought was dodgy earthing, either of the AC supply or individual equpiment (http://www.svconline.com/news/news/understanding-and-controlling-rf-interference/364849), but another thing which can be filthy, or acting like it, are the contacts off and within devices; i've also found new type lightbulbs of the 'cost-effective' variety to be like this. i've even had to add solder to the contacts of some!

i'm just moving over the LED bulbs, from the false-efficient fluorescent compacts (mum and dad, as pensioners, got loads of free ones when they first came out), but i've not any issues. i only buy them out of the bargainbuckets, but try for known makes. it'd be interesting to look inside a few makes, for comparison, and to see how they're dropping and smoothing the power supply. surely they can't be scrimping there?

My mains and distribution earthing is solid (That is correct English, isn't it?)

Now that I know there's an issue, I will do an autopsy next time there's a failure. Of course, if the hype is accurate, I may not live that long.

- - - Updated - - -

A hamateur? I had you pegged as the 11-meter type. ;->

Haven't done it for decades, but as a 14 year old nerd, mostly 40. Today, there's computers, back then AV club, unless you were the real deal and went amateur.

Edit: LOL. missed it pre-caffeine. Yeah, CB was closer to AV club than it was to ham.

I've been accumulating GE-brand LED bulbs whenever they go on sale, and haven't had any RFI problems with those. My main gripe with them is the same as with most CFLs: They're butt-ass ugly. Even the nice new ones that have been color-balanced to produce a spectrum like incandescent bulbs still have a big white plastic base that takes up half their length. For light fixtures where you don't see the bulb, that's often fine. Otherwise, forget it!

I think the culprits might be GE brand....nope, you made me look. OSRAM. At least its a brand that's been around for a while. I remember seeing one of their distribution centers in the 80's.... My paychecks had a GE logo for a while. I know too much about their business practices to pay extra for THAT logo.

Looks don't matter in this case. R20 bulbs in a track lighting fixture. Only the business end is visible, and then only if you look straight into it. Yes, given past issues with heat using incandescent and ....gasp.... brief experiments with halogen, LED is a better solution.

- - - Updated - - -

Then, once on the lamb with his family in tow, his slow mind realizes that his handlers are on the take, so he drives off into some rutted field after getting the idiots to crash their SUV into a tree, but even though they're on foot and he's driving, by running, they're keeping up with his SUV, shooting at him and his family. Then Lou, like a 90 year old grandmother, drives into a tree even though he's only doing about 15 miles an hour. The plot goes down hill from there. Who writes this stuff?

Its 5-0. Suspension of disbelief is integral to the concept. Take a re-look at the original some time.

So yeah, The Washington Post had a big article today about LED bulbs and how much better they are than the old incandescent bulbs. The changeover was part of the 2007, George Bush energy plan. Still, the Post is in favor of the plan, but I guess getting quality bulbs sounds like the way to go.

Like the Huffington Puffington Post, part of the inner circle at the Ministry of Propaganda.

In the past several years, I started replacing my bulbs with the fluorescent bulbs, but they put out a weak amount of light. I'm not sure if they create the same RF problems as I have to get my TV signal via Direct TV as we live surrounded by mountains.

If memory serves, DirecTV signals are up around 10 or 20 gigaHz. Your microwave oven is around 1.2, your phones and wifi router at 2.4 and 5 ghz. Broadcast channel 2 is at 54 megaHz. Completely different deal as far as propogation and interference.

- - - Updated - - -

I haven't noticed any RF problems, but all my bulbs are Phillips models manufactured in France, so I suspect that the quality control is better.
Possible, but you wouldn't know unless you listen to AM radio and/or get your TV signal over the air.

Actually, I could complain to the FCC. Its against the law for products to interfere with broadcast signals. Of course, these days, that sort of windmill tilting is in the Echo Chamber league along with the Do Not Call Registry

Funny, but even if they'd known about the solid-state electronics revolution a century ago, the technology for long distance high-voltage DC transmission just didn't exist, and the efficiency advantages of large-scale AC generation and long-distance transmission were undeniable. Apart from anything else, I doubt that small-scale urban electricity generation using pre-war combustion technology would have survived the clean air movements. Edison may have the last laugh, but that doesn't mean that he was right at the time.

Hard to guess how things MIGHT have gone. The earliest part of the argument was about point of use generation vs large scale distribution. Not so sure that wouldn't have worked long enough to get to present day use of wind and solar.
 
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A

acorn

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For wiw, my hearing aids are non wireles even known brand CFL's are a pain with respect to RFI.
 

ade

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My mains and distribution earthing is solid (That is correct English, isn't it?)
okey-dokey. i only mentioned it because, considering as much as i can, the only real difference(s) between the west and China is the newness of the infrastructure. i'm sure that they don't have 50-odd year old ground-spikes and stuff.
certainly, you'd expect the Chinqs to use the same designs, factories and components in the making of their cheapo items as they would with making the items for their western clients; indeed, you'd also expect them to get their western clients to buy the extra components, and whatever else, needed courtesy of bureaucratic sleights of hand (that's what i'd do, anyway :biggrin:)
afterall, no westerner is going to bring anybody to book over there.

anyway, i simplified my search terms and got more/better results on the issue, and it does seem like there's an issue over here, too. i'm a bit wary about any conclusions as our tv transmitters have had to have their transmissions adjusted/boosted because whichever bright sparks originated the system, they underestimated the impact of hills and tower-blocks. a consequence of that is that a lot of early tv equipment is incompatible with the boosted outputs of the transmitters (this, as far as i'm aware) and may need a firmware upgrade. for a lot of brands, the bin is the only real solution as the supposed over-the-air upgrades don't exist.
i had such an issue with my HDD/PVR.

and i've never had any success with add-on amplifiers; they always seem to make things worse, overall (in a powered state or not). the only real improvements i've seen have been when an external video/PVR is connected.

Now that I know there's an issue, I will do an autopsy next time there's a failure.
just a coincidence, but i had one apart the other night, after it died (Duracell brand). mum said that it started flashing and then went out.
this one had a LED driver IC (checked) and a triac (i think: no code to check) which the one on Wiki doesn't seem to have, going by the picture.
i couldn't find any proper specs on the driver, only similar, but i'm guessing it's a pulse-generator/vibrator (to address the heat issue??? as i read more, some say that's not really an issue).
being and old fart, i'll say that it's just another reason to not like flip-flops :laugh:
 
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Maxx

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and i've never had any success with add-on amplifiers; they always seem to make things worse, overall (in a powered state or not). the only real improvements i've seen have been when an external video/PVR is connected.

For your personal amusement... I installed the antenna and inline amplifier in 1985. Without the amp, I get zip. With it, I'm good on all channels as long as I don't turn on the LED bulbs, and Mrs. Maxx doesn't turn on her XBOX360. I won't bother to look up the amp brand, because the device and its manufacturer almost certainly don't exist today. If it ever burns out, I'm probably screwed.

I'll admit to quite the Rube Goldberg arrangement that theoretically shouldn't work at all, especially some 30 miles from the transmitter sites. 1. 25ft of coax from antenna in the attic to a 15 year old DVD recorder in the basement. I need it there, because the hand me down plasma TV down there is just old enough to be "digital ready", ie, no digital tuner. I use the recorder's tuner and drive the TV via HDMI. Amplifier is between antenna and DVD recorder. 2. coax output from DVD recorder to splitter.
3. Two 25ft lengths of coax from splitter back upstairs to bedroom TV and living room TV respectively

There are ways I could cut down the cable runs, but not without serious reallocation of function and capability, and probably some expenditure on additional components. Remember my cheap genes. Even if I did that, I doubt it would fix the interference problem. Before the latest configuration iteration, I experimented with a single short coax run direct to one TV. The XBOX still killed channel 2.

just a coincidence, but i had one apart the other night, after it died (Duracell brand). mum said that it started flashing and then went out.
this one had a LED driver IC (checked) and a triac (i think: no code to check) which the one on Wiki doesn't seem to have, going by the picture.
i couldn't find any proper specs on the driver, only similar, but i'm guessing it's a pulse-generator/vibrator (to address the heat issue??? as i read more, some say that's not really an issue).
being and old fart, i'll say that it's just another reason to not like flip-flops :laugh:

Whatever's in there, I'm sure its some kind of hacked off square pulse output, not smooth DC, and therein lies the problem. There might be better components in more expensive lamps, but its still going to be square wave, and still going to generate all kinds of spurs.

Edit: I've looked at modern, amplified "HDTV" antennas, but as far as I can tell, the enhancements and improvements have more to do with sorting out urban multipath issues than they do my problem. I'm reluctant to throw money at it in $100 chunks on the chance that it "might" be a solution.
 
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irnub

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Its possible that some higher priced LED bulbs may produce less RFI .... but I haven't tested that myself. Until I have, its nothing but marketing blather as far as I'm concerned.
If you mean that literally, I'm not sure it's worth trying to have a discussion. Assuming you don't: some googling turned up several discussions on various HAM boards complaining of noisy LED bulbs. It was harder to find a list of bulbs that weren't noisy, but several people confirmed that GE didn't appear to be generating near as much interference as other bulbs. Phillips appears to be one of the worst name brand manufacturers.

And as far as everything being made in the same factory in china, the quality of components and manufacturing process isn't what's causing the issue, it's the design of the switching circuit. Adding an additional few cents of components to a bulb probably doesn't add up to the cost of hiring some people with actual credentials and experience to design and test the circuits specifically with EMI in mind.

As far as your problem is concerned, I'd be curious to know what happens if you feed the AC cord running to the light through one of those inductor beads used for noise dampening. Obviously it won't do anything if the switching noise is purely on the DC side, but for the kind of damage it's doing to the TV signal it sounds like it might be causing the noise on the AC side and basically using the entire house as an antenna.
 

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It's been a few years since I last tried using an Oscilloscope, so I'm sure I set it up wrong somewhere. But here is the waveform that my $2.00usd Chinese LED Bulb gave me:

2DollarLEDLightBulb.jpg

It looks horrible :dontgetit: but as I said, I'm sure I set up something wrong... On a side note, as soon as I turned the light on, my carbon monoxide detector started putting out a low volume 1Khz tone for some weird reason, I was sitting next to it.

I'm horrible at remembering things like this :(
 

irnub

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It looks horrible :dontgetit: but as I said, I'm sure I set up something wrong...
It just looks like 60hz AC being rectified. I'm a software guy who just dabbles in electronics, but I wouldn't expect that waveform to cause much in the way of adverse affects since 60hz is everywhere already.

Try setting the timescale small enough to catch signals in the megahertz range and see what you pick up. That rigol should be able to go up to at least 50mhz.
 

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It just looks like 60hz AC being rectified. I'm a software guy who just dabbles in electronics, but I wouldn't expect that waveform to cause much in the way of adverse affects since 60hz is everywhere already.

Try setting the timescale small enough to catch signals in the megahertz range and see what you pick up. That rigol should be able to go up to at least 50mhz.

It took me 40 minutes just to get that signal. I'm so rusty on electronic test devices. :sweatdrop: I bought that in late 2014 and only used it twice, without reading the manual, other than the initial time to make sure everything was calibrated.

The O'scope is 100MHz.
 

ade

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It's been a few years since I last tried using an Oscilloscope,
25+ years since i last used one :biggrin:
i was curious as to whereabouts you were probing with the posted sample? is the blue wave (CH2??) 1volt?

@Maxx: both my TVs (kitchen and bedroom) have 30yo portable TV antennas :biggrin:
View attachment 26064
we had a new rooftop one fitted some years ago (but only the standard type and mum gets HDTV on her telly) after the previous one sprung a leak and dripped water down through the co-ax and began dripping around the box :eek: (i'm blaming magpies as they're buggers for pecking open stuff, just to see what's inside. they used to do it at work with the tinned foods; fecking deadly bastards!). that casued all sorts of recepetion issues.
our local transmitter is about 20 miles away, as the crow flies, but we also get the Welsh transmitter which is about 60 or 70 miles away.
it may be worth your trying individual antennas for each device/set-up.

oh, as for the bulb i dismantled and referred to a triac, i retract that: it's a transistor (as you'd expect, really). i found a circuit diagram which mirrored it as best as could be (and there loads of different designs out there). it's one of the newer style trannies which, to my owd eyes, looks like a triac (serves me right for not drawing the circuit). so, it seems a pretty simple set-up and i wouldn't surprised if the IC is just a newer version of the old 555 timer (and the layout of the rest of it is as you'd expect with a 555).
 

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25+ years since i last used one :biggrin:
i was curious as to whereabouts you were probing with the posted sample? is the blue wave (CH2??) 1volt?

I measured at the output to the LED's.

Yes, I was measuring with Channel 2. If I had went up on the voltage the wave would clip off the screen. I couldn't get it to show correctly :dunno:

@Maxx: both my TVs (kitchen and bedroom) have 30yo portable TV antennas :biggrin:

[IMAGE CLIPPED]

we had a new rooftop one fitted some years ago (but only the standard type and mum gets HDTV on her telly) after the previous one sprung a leak and dripped water down through the co-ax and began dripping around the box :eek: (i'm blaming magpies as they're buggers for pecking open stuff, just to see what's inside. they used to do it at work with the tinned foods; fecking deadly bastards!). that casued all sorts of recepetion issues.
our local transmitter is about 20 miles away, as the crow flies, but we also get the Welsh transmitter which is about 60 or 70 miles away.
it may be worth your trying individual antennas for each device/set-up.

oh, as for the bulb i dismantled and referred to a triac, i retract that: it's a transistor (as you'd expect, really). i found a circuit diagram which mirrored it as best as could be (and there loads of different designs out there). it's one of the newer style trannies which, to my owd eyes, looks like a triac (serves me right for not drawing the circuit). so, it seems a pretty simple set-up and i wouldn't surprised if the IC is just a newer version of the old 555 timer (and the layout of the rest of it is as you'd expect with a 555).

I've heard that Magpies are evil things.

Here's the board in this LED light:
20160421_003805.jpg

20160421_003820.jpg

20160421_003835.jpg
 
M

Maxx

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If you mean that literally, I'm not sure it's worth trying to have a discussion. Assuming you don't: some googling turned up several discussions on various HAM boards complaining of noisy LED bulbs. It was harder to find a list of bulbs that weren't noisy, but several people confirmed that GE didn't appear to be generating near as much interference as other bulbs. Phillips appears to be one of the worst name brand manufacturers.

And as far as everything being made in the same factory in china, the quality of components and manufacturing process isn't what's causing the issue, it's the design of the switching circuit. Adding an additional few cents of components to a bulb probably doesn't add up to the cost of hiring some people with actual credentials and experience to design and test the circuits specifically with EMI in mind.

Bear in mind that, for me, this is largely a cost issue. I only bought the LED bulbs because the price had come down to the point where allegedly long life and low power consumption offset the higher purchase price. A $20 bulb simply doesn't cut it, and I'm not interested enough in the outcome to buy different bulbs for experimentation purposes. I might bite on a GE bulb if I saw an R20 down in the $6 range, and I thank you for doing that search for me.

Failing that, CFL's do an adequate job without creating interference, as do incandescent.

The China thing is a bit of an exaggeration, but it is true that we as consumers are flying blind. There are plenty of instances where the only differences between a house brand and the name brand are price and packaging.

In the case of GE, there are a lot of products with a GE logo on them that aren't even associated with the parent company.... when the businesses got sold off, the buyer got the rights to use GE labeling for some period of time.

Even when you find a brand with a good rep for quality, components and the assembly house can change with a couple of keystrokes in procurement or cost accounting.





As far as your problem is concerned, I'd be curious to know what happens if you feed the AC cord running to the light through one of those inductor beads used for noise dampening. Obviously it won't do anything if the switching noise is purely on the DC side, but for the kind of damage it's doing to the TV signal it sounds like it might be causing the noise on the AC side and basically using the entire house as an antenna.

I do have some filters and ferrites laying about that I'd used trying to tamp down the interference from Mrs. Maxx's XBOX a few years ago. Didn't work. Problem with the bulbs is that they're in a track light fixture, wired into the house wiring (conduit, junction boxes, etc.) It would be a project just to get into it for the experiment. For now, turning off a wall switch when I want to watch Channel 2 is not a big deal. Don't need a light on in the basement to watch TV upstairs, or downstairs for that matter.

Edit: Just for fun, took a bulb out of the track light and stuck it in a regular fixture with a ferrite on the power cord. It did make Channel 2 watchable with the light on. Still have the problem with the track lights, but at least the issue is verified. Perhaps there's a way to <safely> get a ferrite into that circuit.....

- - - Updated - - -

@Maxx: both my TVs (kitchen and bedroom) have 30yo portable TV antennas :biggrin:

we had a new rooftop one fitted some years ago (but only the standard type and mum gets HDTV on her telly) after the previous one sprung a leak and dripped water down through the co-ax and began dripping around the box :eek: (i'm blaming magpies as they're buggers for pecking open stuff, just to see what's inside. they used to do it at work with the tinned foods; fecking deadly bastards!). that casued all sorts of recepetion issues.
our local transmitter is about 20 miles away, as the crow flies, but we also get the Welsh transmitter which is about 60 or 70 miles away.
it may be worth your trying individual antennas for each device/set-up.

That may be necessary if the amplifier ever dies.
attic antenna edit.jpg

I've got another similar to the above out in the garage, redundant since my garage TV died.

P.S. All three TV's running off that one antenna are HD. Antenna really doesn't matter as far as HD is concerned. You've either got sufficient signal strength for the digital tuner or you don't.


oh, as for the bulb i dismantled and referred to a triac, i retract that: it's a transistor (as you'd expect, really). i found a circuit diagram which mirrored it as best as could be (and there loads of different designs out there). it's one of the newer style trannies which, to my owd eyes, looks like a triac (serves me right for not drawing the circuit). so, it seems a pretty simple set-up and i wouldn't surprised if the IC is just a newer version of the old 555 timer (and the layout of the rest of it is as you'd expect with a 555).

Yup. About what I expected to see.
 
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