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Do switch mode power supplies flicker in time with mains?
Do switch mode power supplies flicker in time with mains? Specifically LED power supplies in commercially available domestic lamps. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? And is there any way I can test this? I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz.
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Do switch mode power supplies flicker in time with mains?
William Gothberg "William wrote
Do switch mode power supplies flicker in time with mains? No. Specifically LED power supplies in commercially available domestic lamps. None of mine flicker at all. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? None of mine flicker at all. And is there any way I can test this? Yes, Get or make a strobe disk or use one of the original LP disks that has a strobe disk on it and see what it looks like with the lights illuminating it. You'll get it appearing to freeze when rotating if the light level is varying in synch with the mains frequency. I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. Or they don't flicker at all. No reason why a proper switched mode power supply needs to have any AC component at all on its output. The cruder ones may well do. |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 11:51:35 -0000, Rod Speed wrote:
William Gothberg "William wrote Do switch mode power supplies flicker in time with mains? No. Specifically LED power supplies in commercially available domestic lamps. None of mine flicker at all. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? None of mine flicker at all. And is there any way I can test this? Yes, Get or make a strobe disk or use one of the original LP disks that has a strobe disk on it and see what it looks like with the lights illuminating it. You'll get it appearing to freeze when rotating if the light level is varying in synch with the mains frequency. I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. Or they don't flicker at all. No reason why a proper switched mode power supply needs to have any AC component at all on its output. The cruder ones may well do. They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. But it's nothing like as low as 50Hz. What I want to know is if the higher frequency they're flickering at is anchored with the rise of the AC wave. I.e. will all the LED lights in the room flicker at precisely the same time, or will they be out of synch (due to tolerances in the circuitry of each PSU) and fudge the brightness together. |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 11:56:43 -0000, Adrian Caspersz wrote:
On 19/12/2018 11:23, William Gothberg wrote: Do switch mode power supplies flicker in time with mains? Specifically LED power supplies in commercially available domestic lamps. Look at the infantile name of the poster, It's just a name. the crossposting, To find more people who might know the answer. the stupid question. It's a perfectly sensible question, I want to know if with a lot of similar LED lights, if the whole room will experience flicker. before ye answer, it's hucker again... So what? |
Do switch mode power supplies flicker in time with mains?
"William Gothberg" "William wrote in message ... On Wed, 19 Dec 2018 11:51:35 -0000, Rod Speed wrote: William Gothberg "William wrote Do switch mode power supplies flicker in time with mains? No. Specifically LED power supplies in commercially available domestic lamps. None of mine flicker at all. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? None of mine flicker at all. And is there any way I can test this? Yes, Get or make a strobe disk or use one of the original LP disks that has a strobe disk on it and see what it looks like with the lights illuminating it. You'll get it appearing to freeze when rotating if the light level is varying in synch with the mains frequency. I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. Or they don't flicker at all. No reason why a proper switched mode power supply needs to have any AC component at all on its output. The cruder ones may well do. They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. But it's nothing like as low as 50Hz. What I want to know is if the higher frequency they're flickering at is anchored with the rise of the AC wave. No its not. I.e. will all the LED lights in the room flicker at precisely the same time, or will they be out of synch (due to tolerances in the circuitry of each PSU) Due to it not being synched with the mains, actually. and fudge the brightness together. Its not a fudge, it's the lack of synch. And you should be able to see that by watching the chuck as you move the drill between lights. The rate and direction of rotation should change. |
Lonely Psychotic Senile Ozzie Troll Alert! LOL
On Wed, 19 Dec 2018 22:51:35 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again: No. Trust that senile Ozzietard Rot will be the first to run along and suck off the Scottish ****** and attention whore again! LOL -- The Natural Philosopher about senile Rot: "Rod speed is not a Brexiteer. He is an Australian troll and arsehole." Message-ID: |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 12:28:04 -0000, Rod Speed wrote:
"William Gothberg" "William wrote in message ... On Wed, 19 Dec 2018 11:51:35 -0000, Rod Speed wrote: William Gothberg "William wrote Do switch mode power supplies flicker in time with mains? No. Specifically LED power supplies in commercially available domestic lamps. None of mine flicker at all. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? None of mine flicker at all. And is there any way I can test this? Yes, Get or make a strobe disk or use one of the original LP disks that has a strobe disk on it and see what it looks like with the lights illuminating it. You'll get it appearing to freeze when rotating if the light level is varying in synch with the mains frequency. I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. Or they don't flicker at all. No reason why a proper switched mode power supply needs to have any AC component at all on its output. The cruder ones may well do. They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. But it's nothing like as low as 50Hz. What I want to know is if the higher frequency they're flickering at is anchored with the rise of the AC wave. No its not. I.e. will all the LED lights in the room flicker at precisely the same time, or will they be out of synch (due to tolerances in the circuitry of each PSU) Due to it not being synched with the mains, actually. I meant if the PSUs were absolutely identical, and all the lights were switched on at the same time (with one lightswitch), they should remain in synch forever. But since there are tolerances in all the components in the PSUs, they won't stay in time. and fudge the brightness together. Its not a fudge, it's the lack of synch. I didn't mean fudge, I meant smudge. And you should be able to see that by watching the chuck as you move the drill between lights. The rate and direction of rotation should change. Only if the frequency is different, which I doubt as they are all the same model. What I need is a way of detecting if they're flashing together. |
Lonely Psychotic Senile Ozzie Troll Alert! LOL
On Wed, 19 Dec 2018 23:28:04 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again: FLUSH the two prize idiots' endless idiotic drivel unread again -- Typical retarded "conversation" between the Scottish ****** and senile Ozzietard: Birdbrain: "Horse **** doesn't stink." Senile Rot: "It does if you roll in it." Birdbrain: "I've never worked out why, I assumed it was maybe meateaters that made stinky ****, but then why does vegetarian human **** stink? Is it just the fact that we're capable of digesting meat?" Senile Rot: "Nope, some cow **** stinks too." Message-ID: |
Do switch mode power supplies flicker in time with mains?
Only if the frequency is different, which I doubt as they are all the same model. What I need is a way of detecting if they're flashing together. There are two possibilities. 1) The LEDS flicker at the line rate. In this case they will probably all be in sync. The LEDs flicker at the PSU switching rate. In this case they will NOT be in sync. Switching power supplies are usually free running and the frequency will be drifting around. Even if they are the same model, component tolerances and temperature variations will mean they are on slightly different frequencies and there will be no defined phase relationship. mark |
Do switch mode power supplies flicker in time with mains?
On Wednesday, December 19, 2018 at 9:22:10 AM UTC-5, wrote:
Only if the frequency is different, which I doubt as they are all the same model. What I need is a way of detecting if they're flashing together. There are two possibilities. 1) The LEDS flicker at the line rate. In this case they will probably all be in sync. The LEDs flicker at the PSU switching rate. In this case they will NOT be in sync. Switching power supplies are usually free running and the frequency will be drifting around. Even if they are the same model, component tolerances and temperature variations will mean they are on slightly different frequencies and there will be no defined phase relationship. mark +1 But I doubt the first mode is possible in a properly functioning switching power supply. And AFAIK in a typical switching PS the latter never makes it to the output and if it did, it would be so fast that you would not be able to see it. |
Do switch mode power supplies flicker in time with mains?
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Do switch mode power supplies flicker in time with mains?
On 12/19/18 5:23 AM, William Gothberg wrote:
Do switch mode power supplies flicker in time with mains?* Specifically LED power supplies in commercially available domestic lamps.* By in time, I don't mean at the same 50/60Hz, but anchored to it.* I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random?* And is there any way I can test this?* I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. I once had an audio amplifier with a solar cell rather than a microphone for the input transducer. This made it possible to listen to light. The sun is steady, incandescent lights (AC powered) hum. That was 40 years ago. Maybe something like that would work today. -- 6 days until the winter celebration (Tue Dec 25, 2018 12:00:00 AM for 1 day). Mark Lloyd http://notstupid.us/ "Do not thank God for what man does." [Lemuel K. Washburn, _Is The Bible Worth Reading And Other Essays_, 1911] |
Do switch mode power supplies flicker in time with mains?
On 12/19/18 6:01 AM, William Gothberg wrote:
[snip] They probably are fairly crude.* I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. [snip] -- 6 days until the winter celebration (Tue Dec 25, 2018 12:00:00 AM for 1 day). Mark Lloyd http://notstupid.us/ "Do not thank God for what man does." [Lemuel K. Washburn, _Is The Bible Worth Reading And Other Essays_, 1911] |
Do switch mode power supplies flicker in time with mains?
Mark Lloyd wrote:
I once had an audio amplifier with a solar cell rather than a microphone for the input transducer. This made it possible to listen to light. The sun is steady, incandescent lights (AC powered) hum. That was 40 years ago. Maybe something like that would work today. Certainly if you connect a solar cell to an oscilloscope, you can see the difference between incandescent and LED GU10 lamps fed 240V mains incandescent and LED MR16 lamps fed 12V from an electronic 'transformer' a dimmer feeding either of the above. |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd wrote:
On 12/19/18 6:01 AM, William Gothberg wrote: [snip] They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. It looks absolutely ridiculous with modern cars with LED headlights in films. How hard can it be to put a smoothing capacitor on the output of the power supply? |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 16:18:29 -0000, Mark Lloyd wrote:
On 12/19/18 5:23 AM, William Gothberg wrote: Do switch mode power supplies flicker in time with mains? Specifically LED power supplies in commercially available domestic lamps. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? And is there any way I can test this? I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. I once had an audio amplifier with a solar cell rather than a microphone for the input transducer. This made it possible to listen to light. The sun is steady, incandescent lights (AC powered) hum. That was 40 years ago. Maybe something like that would work today. The trouble is I want to compare 2kHz+ from one light with 2kHz+ from a neighbouring light and see if they're in sync. |
Do switch mode power supplies flicker in time with mains?
On 12/19/18 9:28 AM, Bubba wrote:
[snip] Correct.Â* My strings of cheapo imported LED Christmas lights appear to the naked eye to be on 100%. A simple one would have the LEDs flashing at the powerline frequency with a duty cycle of somewhat less than 50% (somewhat less considering the time that the AC voltage is less than the LEDs threshold). Some strings contain a full-wave rectifier so the frequency will be doubled and the duty cycle almost (almost because of the diode voltage drops) doubled (a little less than 100%). Most of those strings I have have 50, 60, or 70 LEDs in two series, one on each polarity. Both will not light at the same time (since they require different polarities). I have tried it with a diode in series with the string. Only one half lights. Reverse the diode and only the other half lights. A string with a full-wave rectifier will light both series (almost) all the time. The extra diode will give half brightness (I have taken advantage of this for some tape lights that were too bright). However, when viewed through my cheapo webcam, they appear on for 5 seconds, fade to off 2 seconds, off for 5 seconds, fade to on 2 seconds, lather/rinse/repeat. This is affected by frequencies in the camera. They do have interesting interactions. -- 6 days until the winter celebration (Tue Dec 25, 2018 12:00:00 AM for 1 day). Mark Lloyd http://notstupid.us/ "Do not thank God for what man does." [Lemuel K. Washburn, _Is The Bible Worth Reading And Other Essays_, 1911] |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 16:34:11 -0000, whisky-dave wrote:
On Wednesday, 19 December 2018 16:21:43 UTC, Mark Lloyd wrote: On 12/19/18 6:01 AM, William Gothberg wrote: [snip] They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. You can also observe such things using a smartphone that has a high FPS rate for recodring movie. I can see the labs lights flicker when I film at 240FPS standard 60 and everything seems fine. Everybody seems to constantly cut corners. Lights should just be on, no flicker at all. ****ing annoying if you have decent eyesight, I can see the flicker from almost everyone's LED tail lights. |
Do switch mode power supplies flicker in time with mains?
In article , "William
says... On Wed, 19 Dec 2018 16:34:11 -0000, whisky-dave wrote: On Wednesday, 19 December 2018 16:21:43 UTC, Mark Lloyd wrote: On 12/19/18 6:01 AM, William Gothberg wrote: [snip] They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. You can also observe such things using a smartphone that has a high FPS rate for recodring movie. I can see the labs lights flicker when I film at 240FPS standard 60 and everything seems fine. Everybody seems to constantly cut corners. Lights should just be on, no flicker at all. ****ing annoying if you have decent eyesight, I can see the flicker from almost everyone's LED tail lights. Then stop looking at them. |
Do switch mode power supplies flicker in time with mains?
Well the answer as in many things these days is it depends.
Some are very simple and do have a kind of pulsing taken from ripple on the mains. Others seem to not do this, indeed poking a phototransistor connected to an amplifier shows many different results. the same seems to go for CFLs as well. You would need to know what circuit they were using etc to figure out why. One particular led in a stood across the road has a 1khz whine when point the device at it but modulated onto a 100 hz buzz. I often wonder if there is some jiggery pokery going on to drive leds hard for split seconds to make them brighter. Brian -- ----- -- This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please Note this Signature is meaningless.! "William Gothberg" "William wrote in message ... Do switch mode power supplies flicker in time with mains? Specifically LED power supplies in commercially available domestic lamps. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? And is there any way I can test this? I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. |
Do switch mode power supplies flicker in time with mains?
On Wednesday, December 19, 2018 at 11:35:06 AM UTC-5, William Gothberg wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd wrote: On 12/19/18 6:01 AM, William Gothberg wrote: [snip] They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. It looks absolutely ridiculous with modern cars with LED headlights in films. How hard can it be to put a smoothing capacitor on the output of the power supply? I've never noticed that. Any films come to mind? It seems especially weird, since cars have a 12V supply with a big battery to smooth anything out. I guess the power supply that reduces that to whatever the LED headlights use though might have a switching power supply these days too. |
Do switch mode power supplies flicker in time with mains?
On 12/19/2018 11:36 AM, William Gothberg wrote:
On Wed, 19 Dec 2018 16:18:29 -0000, Mark Lloyd wrote: On 12/19/18 5:23 AM, William Gothberg wrote: Do switch mode power supplies flicker in time with mains?* Specifically LED power supplies in commercially available domestic lamps. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random?* And is there any way I can test this?* I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. I once had an audio amplifier with a solar cell rather than a microphone for the input transducer. This made it possible to listen to light. The sun is steady, incandescent lights (AC powered) hum. That was 40 years ago. Maybe something like that would work today. The trouble is I want to compare 2kHz+ from one light with 2kHz+ from a neighbouring light and see if they're in sync. Maybe use a dual trace oscilloscope? Since this landed in alt.home.repair, I gotta ask.* Do you have single-phase or two-phase? |
Do switch mode power supplies flicker in time with mains?
"William Gothberg" "William wrote in message ... On Wed, 19 Dec 2018 12:28:04 -0000, Rod Speed wrote: "William Gothberg" "William wrote in message ... On Wed, 19 Dec 2018 11:51:35 -0000, Rod Speed wrote: William Gothberg "William wrote Do switch mode power supplies flicker in time with mains? No. Specifically LED power supplies in commercially available domestic lamps. None of mine flicker at all. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? None of mine flicker at all. And is there any way I can test this? Yes, Get or make a strobe disk or use one of the original LP disks that has a strobe disk on it and see what it looks like with the lights illuminating it. You'll get it appearing to freeze when rotating if the light level is varying in synch with the mains frequency. I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. Or they don't flicker at all. No reason why a proper switched mode power supply needs to have any AC component at all on its output. The cruder ones may well do. They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. But it's nothing like as low as 50Hz. What I want to know is if the higher frequency they're flickering at is anchored with the rise of the AC wave. No its not. I.e. will all the LED lights in the room flicker at precisely the same time, or will they be out of synch (due to tolerances in the circuitry of each PSU) Due to it not being synched with the mains, actually. I meant if the PSUs were absolutely identical, They never can be. and all the lights were switched on at the same time (with one lightswitch), they should remain in synch forever. Nope, because the frequency at which the PSU works is entirely determined by the component tolerances when it isnt operating at 50Hz because it isnt a simple capacitance dropper. But since there are tolerances in all the components in the PSUs, Most of the components in the PSU don't determine the frequency it operates at. they won't stay in time. They never will without an explicit design that keeps the frequency in synch with the mains and there is no point in the extra components to do that, so they don't. The only exception is very simple capacitance droppers that operate at mains frequency and the effect you are getting with the drill chuck proves that yours arent that. and fudge the brightness together. Its not a fudge, it's the lack of synch. I didn't mean fudge, I meant smudge. And you should be able to see that by watching the chuck as you move the drill between lights. The rate and direction of rotation should change. Only if the frequency is different, which I doubt as they are all the same model. The frequencys will be slightly different because of component variation. What I need is a way of detecting if they're flashing together. Like I said, do the drill chuck thing with all the lights on at night and move the drill between lights relatively close to the lights. |
Do switch mode power supplies flicker in time with mains?
Yes I know they have very bright pulsed LEDs in car lights so they can get pretend to look brighter than they really are. The average light output is the same, but the peak output is higher, which fools our eyes. Damn annoying if you have decent eyesight and can see the flicker. And also if you try to film it - I see TV programs about cars where the headlights are flashing as they aren't in time with the camera frames.
On Wed, 19 Dec 2018 17:11:20 -0000, Brian Gaff wrote: Well the answer as in many things these days is it depends. Some are very simple and do have a kind of pulsing taken from ripple on the mains. Others seem to not do this, indeed poking a phototransistor connected to an amplifier shows many different results. the same seems to go for CFLs as well. You would need to know what circuit they were using etc to figure out why. One particular led in a stood across the road has a 1khz whine when point the device at it but modulated onto a 100 hz buzz. I often wonder if there is some jiggery pokery going on to drive leds hard for split seconds to make them brighter. Brian |
Troll-feeding Senile YANKIETARD Alert!
On Wed, 19 Dec 2018 09:47:17 -0800 (PST), tardo_4 an especially stupid,
troll-feeding, senile idiot, blathered: I've never noticed that. You ALSO never noticed that the sociopathic ****** keeps leading all you senile Yankietards around by your stupid senile noses ...TIME and AGAIN! tsk |
Troll-feeding Senile YANKIETARD Alert!
On Wed, 19 Dec 2018 10:18:29 -0600, Mark Lloyd, another mentally retarded,
troll-feeding, senile Yankietard, blathered: I once had an audio amplifier with a solar cell That's more cells than you have brain cells, troll-feeding senile idiot! |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 18:33:09 -0000, Rod Speed wrote:
"William Gothberg" "William wrote in message ... On Wed, 19 Dec 2018 12:28:04 -0000, Rod Speed wrote: "William Gothberg" "William wrote in message ... On Wed, 19 Dec 2018 11:51:35 -0000, Rod Speed wrote: William Gothberg "William wrote Do switch mode power supplies flicker in time with mains? No. Specifically LED power supplies in commercially available domestic lamps. None of mine flicker at all. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? None of mine flicker at all. And is there any way I can test this? Yes, Get or make a strobe disk or use one of the original LP disks that has a strobe disk on it and see what it looks like with the lights illuminating it. You'll get it appearing to freeze when rotating if the light level is varying in synch with the mains frequency. I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. Or they don't flicker at all. No reason why a proper switched mode power supply needs to have any AC component at all on its output. The cruder ones may well do. They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. But it's nothing like as low as 50Hz. What I want to know is if the higher frequency they're flickering at is anchored with the rise of the AC wave. No its not. I.e. will all the LED lights in the room flicker at precisely the same time, or will they be out of synch (due to tolerances in the circuitry of each PSU) Due to it not being synched with the mains, actually. I meant if the PSUs were absolutely identical, They never can be. Yes I know. It was hypothetical. and all the lights were switched on at the same time (with one lightswitch), they should remain in synch forever. Nope, because the frequency at which the PSU works is entirely determined by the component tolerances when it isnt operating at 50Hz because it isnt a simple capacitance dropper. But since there are tolerances in all the components in the PSUs, Most of the components in the PSU don't determine the frequency it operates at. they won't stay in time. They never will without an explicit design that keeps the frequency in synch with the mains and there is no point in the extra components to do that, so they don't. Which is what I thought. The only exception is very simple capacitance droppers that operate at mains frequency and the effect you are getting with the drill chuck proves that yours arent that. and fudge the brightness together. Its not a fudge, it's the lack of synch. I didn't mean fudge, I meant smudge. And you should be able to see that by watching the chuck as you move the drill between lights. The rate and direction of rotation should change. Only if the frequency is different, which I doubt as they are all the same model. The frequencys will be slightly different because of component variation. I would have thought so, so why is it that in my room with 10 such lights, I still get flicker. Shouldn't they fill in each other's gaps? What I need is a way of detecting if they're flashing together. Like I said, do the drill chuck thing with all the lights on at night and move the drill between lights relatively close to the lights. Just did that and proved nothing. Clearly I get the same effect under every light, as they'll be pretty similar frequencies. I'm not going to be able to tell the difference between them with something as simple as a drill chuck. Presumably they're something like 1995 Hz, 2001 Hz, 2003 Hz, etc. All I can think of to prove it would be a higher speed camera so I can spot them being on at different times. |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 18:03:19 -0000, Clark W. Griswold wrote:
On 12/19/2018 11:36 AM, William Gothberg wrote: On Wed, 19 Dec 2018 16:18:29 -0000, Mark Lloyd wrote: On 12/19/18 5:23 AM, William Gothberg wrote: Do switch mode power supplies flicker in time with mains? Specifically LED power supplies in commercially available domestic lamps. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? And is there any way I can test this? I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. I once had an audio amplifier with a solar cell rather than a microphone for the input transducer. This made it possible to listen to light. The sun is steady, incandescent lights (AC powered) hum. That was 40 years ago. Maybe something like that would work today. The trouble is I want to compare 2kHz+ from one light with 2kHz+ from a neighbouring light and see if they're in sync. Maybe use a dual trace oscilloscope? Haven't got one unfortunately. Since this landed in alt.home.repair, I gotta ask. Do you have single-phase or two-phase? Single. I'm in the UK. |
Troll-feeding Senile YANKIETARD Alert!
On Wed, 19 Dec 2018 13:03:19 -0500, Clark W. Griswold, another brain
damaged, troll-feeding, senile Yankietard, blathered: Maybe use a dual trace oscilloscope? Since this landed in alt.home.repair, I gotta ask.* Do you have single-phase or two-phase? He to no brain, that's his problem! All he knows to do is how to bait the senile Yanks on Usenet with his insipid trolls! Get a clue, Yankietard! |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 17:47:17 -0000, trader_4 wrote:
On Wednesday, December 19, 2018 at 11:35:06 AM UTC-5, William Gothberg wrote: On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd wrote: On 12/19/18 6:01 AM, William Gothberg wrote: [snip] They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. It looks absolutely ridiculous with modern cars with LED headlights in films. How hard can it be to put a smoothing capacitor on the output of the power supply? I've never noticed that. Any films come to mind? A lot of Top Gear programs showing the DRLs of cars fitted with LEDs. With a feature film, they might take the time/trouble/money to do something to stop it. It seems especially weird, since cars have a 12V supply with a big battery to smooth anything out. I guess the power supply that reduces that to whatever the LED headlights use though might have a switching power supply these days too. AFAIK it's deliberate, making the LEDs operate brighter than they are capable of, but only 1/4 of the time. Our eyes just see the brightest part of the cycle, so we think they're four times brighter than the LED is really capable of, without overheating itself. |
Troll-feeding Senile IDIOT Alert!
On Wed, 19 Dec 2018 17:11:20 -0000, Brainless & Daft, the notorious,
troll-feeding senile idiot, blathered Well the answer as in many things these days is it depends. The ONLY right answer here is that HE's a dumb sociopathic troll and attention whore, and YOU are a dumb mentally deficient troll-feeding senile idiot! |
Lonely Psychotic Senile Ozzie Troll Alert! LOL
On Thu, 20 Dec 2018 05:33:09 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again: FLUSH another 126 lines of the two prize idiots' endless idiotic babble unread -- Another retarded "conversation" between Birdbrain and senile Rot: Senile Rot: " Did you ever dig a hole to bury your own ****?" Birdbrain: "I do if there's no flush toilet around." Senile Rot: "Yeah, I prefer camping like that, off by myself with no dunnys around and have always buried the ****." MID: |
Do switch mode power supplies flicker in time with mains?
On Wednesday, December 19, 2018 at 2:36:55 PM UTC-5, William Gothberg wrote:
On Wed, 19 Dec 2018 17:47:17 -0000, trader_4 wrote: On Wednesday, December 19, 2018 at 11:35:06 AM UTC-5, William Gothberg wrote: On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd wrote: On 12/19/18 6:01 AM, William Gothberg wrote: [snip] They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. It looks absolutely ridiculous with modern cars with LED headlights in films. How hard can it be to put a smoothing capacitor on the output of the power supply? I've never noticed that. Any films come to mind? A lot of Top Gear programs showing the DRLs of cars fitted with LEDs. With a feature film, they might take the time/trouble/money to do something to stop it. It seems especially weird, since cars have a 12V supply with a big battery to smooth anything out. I guess the power supply that reduces that to whatever the LED headlights use though might have a switching power supply these days too. AFAIK it's deliberate, making the LEDs operate brighter than they are capable of, but only 1/4 of the time. Our eyes just see the brightest part of the cycle, so we think they're four times brighter than the LED is really capable of, without overheating itself. If that's the case, then many similar LEDs, eg house bulbs should be designed the same way. Which means the pulsing is designed in, deliberate and has nothing to do with the type of power supply or that the power comes from AC. First time I've heard of this, but it's certainly possible. |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 20:30:37 -0000, trader_4 wrote:
On Wednesday, December 19, 2018 at 2:36:55 PM UTC-5, William Gothberg wrote: On Wed, 19 Dec 2018 17:47:17 -0000, trader_4 wrote: On Wednesday, December 19, 2018 at 11:35:06 AM UTC-5, William Gothberg wrote: On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd wrote: On 12/19/18 6:01 AM, William Gothberg wrote: [snip] They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. It looks absolutely ridiculous with modern cars with LED headlights in films. How hard can it be to put a smoothing capacitor on the output of the power supply? I've never noticed that. Any films come to mind? A lot of Top Gear programs showing the DRLs of cars fitted with LEDs. With a feature film, they might take the time/trouble/money to do something to stop it. It seems especially weird, since cars have a 12V supply with a big battery to smooth anything out. I guess the power supply that reduces that to whatever the LED headlights use though might have a switching power supply these days too. AFAIK it's deliberate, making the LEDs operate brighter than they are capable of, but only 1/4 of the time. Our eyes just see the brightest part of the cycle, so we think they're four times brighter than the LED is really capable of, without overheating itself. If that's the case, then many similar LEDs, eg house bulbs should be designed the same way. You'd think so. Which means the pulsing is designed in, deliberate and has nothing to do with the type of power supply or that the power comes from AC. First time I've heard of this, but it's certainly possible. The one's I've got I believe are not pulsed on purpose. I say this because one of them failed - it started flashing at about 3Hz. I fixed it by just putting a fairly large smoothing electrolytic capacitor on the output of the 70V DC PSU. It now operates (and has for a year) at the same brightness as the others without breaking the LEDs. And it's lovely and smooth - no high frequency flicker! If the others annoyed me enough, I'd take them all apart and fit capacitors. As it is I only actually notice the flicker if I move my line of vision rapidly across them, or I'm using something like a drill that's moving, and it appears to rotate the wrong way. But some car lights flicker slow enough that you see them, and also your eyes are moving about when driving anyway so you're more likely to see it. |
Troll-feeding Senile YANKIETARD Alert!
On Wed, 19 Dec 2018 12:30:37 -0800 (PST), tardo_4 an especially stupid,
troll-feeding, senile idiot, blathered: First time I've heard of this, but it's certainly possible. Most likely also the last time, you troll-feeding asshole! G |
Do switch mode power supplies flicker in time with mains?
On Wednesday, December 19, 2018 at 11:36:48 AM UTC-5, William Gothberg wrote:
On Wed, 19 Dec 2018 16:18:29 -0000, Mark Lloyd wrote: On 12/19/18 5:23 AM, William Gothberg wrote: Do switch mode power supplies flicker in time with mains? Specifically LED power supplies in commercially available domestic lamps. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? And is there any way I can test this? I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. I once had an audio amplifier with a solar cell rather than a microphone for the input transducer. This made it possible to listen to light. The sun is steady, incandescent lights (AC powered) hum. That was 40 years ago. Maybe something like that would work today. The trouble is I want to compare 2kHz+ from one light with 2kHz+ from a neighbouring light and see if they're in sync. it is very unlikely that they will be in sync. mark |
Troll-feeding Senile YANKIETARD Alert!
|
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 21:33:32 -0000, wrote:
On Wednesday, December 19, 2018 at 11:36:48 AM UTC-5, William Gothberg wrote: On Wed, 19 Dec 2018 16:18:29 -0000, Mark Lloyd wrote: On 12/19/18 5:23 AM, William Gothberg wrote: Do switch mode power supplies flicker in time with mains? Specifically LED power supplies in commercially available domestic lamps. By in time, I don't mean at the same 50/60Hz, but anchored to it. I.e. if you have several such lamps each with their own built in supply, will they all flicker in time, using the mains frequency to keep them in time, or will they be random, making the room overall not flicker due to them all being random? And is there any way I can test this? I tried taking photos of them, but my camera only goes as fast as 1/2000th of a second, which shows all the lights at the same brightness each time, I suspect the flicker is above 2000Hz. I once had an audio amplifier with a solar cell rather than a microphone for the input transducer. This made it possible to listen to light. The sun is steady, incandescent lights (AC powered) hum. That was 40 years ago. Maybe something like that would work today. The trouble is I want to compare 2kHz+ from one light with 2kHz+ from a neighbouring light and see if they're in sync. it is very unlikely that they will be in sync. mark Agreed. All I can detect (with my digital camera) is that one brand of LED light I have flickers about 5 times less (not sure if it's smother or faster) than the others. It's also the brand that lasts longer, probably better designed overall. |
Do switch mode power supplies flicker in time with mains?
On Wed, 19 Dec 2018 16:45:29 -0000, Snicker wrote:
In article , "William says... On Wed, 19 Dec 2018 16:34:11 -0000, whisky-dave wrote: On Wednesday, 19 December 2018 16:21:43 UTC, Mark Lloyd wrote: On 12/19/18 6:01 AM, William Gothberg wrote: [snip] They probably are fairly crude. I know they flicker, for example if I use my cordless drill, the chuck appears to spin the wrong way under the LED lighting. I remember seeing that with a washing machine (under fluorescent lights). As the tub was slowing down, the row of holes around the tub would appear to reverse direction. Same thing with (spoked) wagon wheels in movies. You can also observe such things using a smartphone that has a high FPS rate for recodring movie. I can see the labs lights flicker when I film at 240FPS standard 60 and everything seems fine. Everybody seems to constantly cut corners. Lights should just be on, no flicker at all. ****ing annoying if you have decent eyesight, I can see the flicker from almost everyone's LED tail lights. Then stop looking at them. I value the front of my car. |
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