"William Gothberg" "William wrote in message
news
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?

No point when the only thing that has a problem is videos.

You don't even see a problem with dashcams.

"William Gothberg" "William wrote in message
news
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.

They wont be. They would have to have extra to synch
to the mains and there is absolutely no reason to do that.

On Thu, 20 Dec 2018 10:53:42 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

You don't even see a problem with dashcams.

We see what a problem retarded trolls like the two of you present!

--
Richard addressing Rot Speed:
"**** you're thick/pathetic excuse for a troll."
MID:

On Thu, 20 Dec 2018 10:56:35 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:


They wont be. They would have to have extra to synch
to the mains and there is absolutely no reason to do that.

No lights could be as synched as you two inseparable trolling prize idiots!
BG

--
about senile Rot Speed:
"This is like having a conversation with someone with brain damage."
MID:

On Wed, 19 Dec 2018 23:56:35 -0000, Rod Speed wrote:



"William Gothberg" "William wrote in message
news
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.

They wont be. They would have to have extra to synch
to the mains and there is absolutely no reason to do that.

Agreed.

On Wed, 19 Dec 2018 23:53:42 -0000, Rod Speed wrote:



"William Gothberg" "William wrote in message
news
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?

No point when the only thing that has a problem is videos.

You don't even see a problem with dashcams.

You should. Surely they operate in a similar way to movie cameras?

On Wed, 19 Dec 2018 23:53:42 -0000, Rod Speed wrote:



"William Gothberg" "William wrote in message
news
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?

No point when the only thing that has a problem is videos.

It's ****ing annoying watching them on TV.

You don't even see a problem with dashcams.

There's a damn big problem with distracting drivers. Anyone with decent sight can see it.

"William Gothberg" "William wrote in message
news
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.

What they actually do is only provide
what it makes any sense to provide.

Lights should just be on, no flicker at all.

None of mine flicker.

****ing annoying if you have decent eyesight, I can see the flicker from
almost everyone's LED tail lights.

Stiff **** for you. You're a freak and get to like that or lump it.

"Brian Gaff" wrote in message
news
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.

Yes, there is, particularly with the brighter ones like car headlights etc.

"William Gothberg" "William wrote in message
news
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.

"William Gothberg" "William wrote in message
news
On Wed, 19 Dec 2018 18:33:09 -0000, Rod Speed
wrote:



"William Gothberg" "William wrote in message
news
On Wed, 19 Dec 2018 12:28:04 -0000, Rod Speed
wrote:



"William Gothberg" "William wrote in message
news 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.

Because you were silly enough to buy the cheapest
**** when your eyes can see the flicker.

Shouldn't they fill in each other's gaps?

Nope, because there will always be some places
where something is primarily illuminated by the
one light and so you will see that flicker, even
if ensure you can never see the bulb itself and
I bet you can actually see the bulbs directly.

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.

You should be able to see the visible effect change as
you move the rotating chuck from under one light to
under another, particularly as you go from one to
another with the chuck illuminated by two lights.

Its academic anyway, there is no way that your
cheap leds will be deliberately synched to the
mains, because it costs more to do that.

I'm not going to be able to tell the difference between them with
something as simple as a drill chuck.

Yes you are when you can see the strobe effect with the drill chuck.

Presumably they're something like 1995 Hz, 2001 Hz, 2003 Hz, etc.

Yes.

All I can think of to prove it would be a higher speed camera so I can
spot them being on at different times.

And if you had a decent smartphone you could do that
with that, but since you are too stupid to have one...

On Thu, 20 Dec 2018 01:31:30 -0000, Rod Speed wrote:



"Brian Gaff" wrote in message
news
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.

Yes, there is, particularly with the brighter ones like car headlights etc.

Those designers need to do more research and realise that a lot of the population have eyesight good enough to detect that flicker and should therefore increase the frequency of the flicker, or they're causing distractions and a danger on the roads.

"William Gothberg" "William wrote in message
news
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.

"William Gothberg" "William wrote in message
news
On Wed, 19 Dec 2018 23:53:42 -0000, Rod Speed
wrote:



"William Gothberg" "William wrote in message
news
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?

No point when the only thing that has a problem is videos.

You don't even see a problem with dashcams.

You should.

But you don't.

Surely they operate in a similar way to movie cameras?

It must be more complicated than that, most likely with the shutter time.

"William Gothberg" "William wrote in message
news
On Wed, 19 Dec 2018 23:53:42 -0000, Rod Speed
wrote:



"William Gothberg" "William wrote in message
news
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?

No point when the only thing that has a problem is videos.

It's ****ing annoying watching them on TV.

Doesn't annoy me.

You don't even see a problem with dashcams.

There's a damn big problem with distracting drivers. Anyone with decent
sight can see it.

Clearly it doesn't annoy them enough to matter or they
arent as stupid as you and don't get annoyed by it.

On Wed, 19 Dec 2018 11:23:00 -0000, "William Gothberg" "William
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.
Leds (at least white ones) on a switch mode supply will not flicker
because the persistance of the phosphor is longer than the period of
the switching frequency which is more than 100kHz - typically 2 mhz.
The answer to the second part of the question is no, the switching is
not syncronized to the mains frequency on MOST switch mode power
supplies.

On Wed, 19 Dec 2018 12:49:47 -0000, "William Gothberg" "William
wrote:

On Wed, 19 Dec 2018 12:28:04 -0000, Rod Speed wrote:



"William Gothberg" "William wrote in message
news
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.
Why??? If the frequency is IDENTICAL (unlikely with production
"tolerances" of consumer grade SMPS wall warts) the chance of them
being EXACTLY in phase is remote at best as the "clock" trigger is
generally not based on the mains frequency. Even if they STARTED
exactly in phase, the frequency drift of the SMPS clock would take
them out of synch pretty quickly - and they would go in and out of
phase over time.

And why do ypu NEED to know if they are synched? Just curious.

On Wed, 19 Dec 2018 12:49:47 -0000, "William Gothberg" "William
wrote:

On Wed, 19 Dec 2018 12:28:04 -0000, Rod Speed wrote:



"William Gothberg" "William wrote in message
news
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.


Dp ypou KNOW it is a true SMPS? or is it just a edge triggered
chopper feeding a full wave bridge rectifier? Something like a dimmer
switch feeding a rectifier with a crude filter on the output? - or
even a simple transformer and rectifier? or a "capacitive dropper"
circuit????
ANy of these will flicker with mains frequency or a multiple - which
COULD be filtered to reduce or eliminate the flicker.

On Wed, 19 Dec 2018 10:21:41 -0600, 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.

[snip]
Very obvious with flourescents.

On Wed, 19 Dec 2018 19:36:51 -0000, "William Gothberg" "William
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.

That is PWM Overdrive. Peak junction current is over the nominal
rating, but the average power consumption is below nominalmaximum
current - and the peak lumen output is significantly enhanced without
reducing the junction life appreciably.
THIS would definitely cause flicker as there is a "significant" dead
period between the "strobe flashes"

"William Gothberg" "William wrote in message
news
On Thu, 20 Dec 2018 01:31:30 -0000, Rod Speed
wrote:



"Brian Gaff" wrote in message
news
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.

Yes, there is, particularly with the brighter ones like car headlights
etc.

Those designers need to do more research and realise that a lot of the
population have eyesight good enough to detect that flicker

In fact **** all of them do and they clearly don't themselves.

and should therefore increase the frequency of the flicker, or they're
causing distractions and a danger on the roads.

Clearly those that set the standards for cars know otherwise.

You're just a freak.


"William Gothberg" "William wrote in message
news 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.

On Thu, 20 Dec 2018 00:08:22 -0000, "William Gothberg" "William
wrote:

On Wed, 19 Dec 2018 23:53:42 -0000, Rod Speed wrote:



"William Gothberg" "William wrote in message
news
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?

No point when the only thing that has a problem is videos.

You don't even see a problem with dashcams.

You should. Surely they operate in a similar way to movie cameras?


Different frame rates.

On Wed, 19 Dec 2018 16:39:50 -0000, "William Gothberg" "William
wrote:

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.


This is sounding more and more like our "engineer friend" who needs
to do his own tire repairs and alignments and clutch repairs.

On Wed, 19 Dec 2018 16:36:48 -0000, "William Gothberg" "William
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.
2 channel scope should do the trick

On Wed, 19 Dec 2018 13:03:19 -0500, "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?

Since this landed in alt.home.repair, I gotta ask.* Do you have single-phase or two-phase?
No such thing as "2 phase" -

On Wed, 19 Dec 2018 19:34:57 -0000, "William Gothberg" "William
wrote:

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.
so 50 Htz - you can almost see an incandescent flicker at that
frequency (at 25 you could)

(also rules out the previously mentioned "engineer friend")

On Thu, 20 Dec 2018 03:09:44 -0000, "William Gothberg" "William
wrote:

On Thu, 20 Dec 2018 01:31:30 -0000, Rod Speed wrote:



"Brian Gaff" wrote in message
news
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.

Yes, there is, particularly with the brighter ones like car headlights etc.

Those designers need to do more research and realise that a lot of the population have eyesight good enough to detect that flicker and should therefore increase the frequency of the flicker, or they're causing distractions and a danger on the roads.

"William Gothberg" "William wrote in message
news 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.


PLONK

Mark Lloyd wrote on 20/12/2018 3:21 AM:
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.
... and, in real life, the Mag wheels of some cars seem to be spinning
backwards, dependant on the speed at which the car is travelling!!

--
Daniel

Bubba wrote:
On 12/19/18 9:22 AM, wrote:
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

Correct. My strings of cheapo imported LED Christmas lights appear to
the naked eye to be on 100%.

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.

It's so simple to see 60 or 120 Hz flicker. Everyone knows how move your
eyes quickly around the light source and lines will be visible with blank
sections. Your eys turn into icilloscope. Everyone ? Anyone ?

Greg

Bubba wrote:
On 12/19/18 9:22 AM, wrote:
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

Correct. My strings of cheapo imported LED Christmas lights appear to
the naked eye to be on 100%.

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.

Clare Snyder wrote:
On Wed, 19 Dec 2018 19:34:57 -0000, "William Gothberg" "William
wrote:

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.
so 50 Htz - you can almost see an incandescent flicker at that
frequency (at 25 you could)

(also rules out the previously mentioned "engineer friend")

Lights flicker at twice the frequency, once for positive cycle, and once
for negative cycle. LEDs only once unles using a bridge rectifier, or
steady on using DC. Even though blinking they look normal straight on, my
brain says something is wrong

Greg

On Wed, 19 Dec 2018 23:14:28 -0500, Clare Snyder, another brain damaged,
troll-feeding, senile Yankietard, blathered:

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.

Dp ypou KNOW it is a true SMPS?

ALL he knows is that he can bait ANY senile Yank with the silliest
"questions" on ahr, you ****ing stupid Yankietards! tsk

On Wed, 19 Dec 2018 23:22:39 -0500, Clare Snyder, another brain damaged,
troll-feeding, senile Yankietard, blathered:


THIS would definitely cause flicker as there is a "significant" dead
period between the "strobe flashes"

Somewhat like the troll's brain and the brains of you senile Yanks function
then, eh? LOL

On Thu, 20 Dec 2018 14:13:16 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

It must be more complicated than that, most likely with the shutter time.

OTOH, baiting you senile idiots always comes EASY to him! LOL

--
about senile Rot Speed:
"This is like having a conversation with someone with brain damage."
MID:

On Thu, 20 Dec 2018 14:14:58 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

It's ****ing annoying watching them on TV.

Doesn't annoy me.

Let's just agree that BOTH of you idiotic sociopaths keep annoying normally
evolved humans!

On Wed, 19 Dec 2018 23:24:20 -0500, Clare Snyder, another brain damaged,
troll-feeding, senile Yankietard, blathered:


You should. Surely they operate in a similar way to movie cameras?

Different frame rates.

That poor retard sure understands how to bait you senile assholes with the
dumbest questions, eh? LOL

dOn Thu, 20 Dec 2018 12:13:07 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

****ing annoying if you have decent eyesight, I can see the flicker from
almost everyone's LED tail lights.

Stiff **** for you. You're a freak and get to like that or lump it.

He's a TROLL, and he gets you to suck him off, EVERY time he feels like he
wants to be sucked off by you! LOL

--
The Natural Philosopher about senile Rot:
"Rod speed is not a Brexiteer. He is an Australian troll and arsehole."
Message-ID:

On Wed, 19 Dec 2018 23:27:41 -0500, Clare Snyder, another brain damaged,
troll-feeding, senile Yankietard, blathered:

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.

This is sounding more and more like our "engineer friend" who needs
to do his own tire repairs and alignments and clutch repairs.

Are you on to something finally, in your senile old age? BG

On Thu, 20 Dec 2018 12:31:30 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:


Yes, there is, particularly with the brighter ones like car headlights etc.

Alas, the light in your senile head doesn't shine too bright, senile oaf!
G

On Wed, 19 Dec 2018 23:34:08 -0500, Clare Snyder, another brain damaged,
troll-feeding, senile Yankietard, blathered:


so 50 Htz - you can almost see an incandescent flicker at that
frequency (at 25 you could)

(also rules out the previously mentioned "engineer friend")

Gosh... are you daft!

On Thu, 20 Dec 2018 00:14:38 -0500, Clare Snyder, another brain damaged,
troll-feeding, senile Yankietard, blathered:

PLONK

He'll get you AGAIN, SOON! Just wait and see! BG

On Wed, 19 Dec 2018 23:30:21 -0500, Clare Snyder, another brain damaged,
troll-feeding, senile Yankietard, blathered:


The trouble is I want to compare 2kHz+ from one light with 2kHz+ from a
neighbouring light and see if they're in sync.
2 channel scope should do the trick

Senile idiot doesn't get it: ONE single idiotic bait by him does the trick
....and you senile Yankietards will run along to swallow his bait again,
hook, line and sinker, EVERY time! LOL