Do switch mode power supplies flicker in time with mains?

[Rod Speed]

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...

On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd <not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get enough
brightness out of LEDs that fit into the lamp holder. The LEDs would
get too hot trying to give out enough brightness for a car headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye). Perhaps they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or you're in
a
country that uses different car lights than here in the USA. There
are a lot of cars with LED lighting, headlights and rear lights, and
I've never noticed this flickering, nor have I ever heard it mentioned
before this thread. I haven't noticed flickering from any LED lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done. Nor have I
heard anyone else mention it. Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything. If just
scanning reveals it, you;d think a lot of people would be noticing it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

> similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

Don't most cars have LEDs now? Or does your area have a lot of older
cars? People (stupidly) around here seem to like cars that are no more
than 10 years old. I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

 

[%]

On 2018-12-20 1:56 p.m., William Gothberg wrote:

On Thu, 20 Dec 2018 20:40:26 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 1:30 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zubnqbkho5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn
jon.fairbairn@cl.cam.ac.uk> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> writes:
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.

Try a longer exposure and move the light rapidly relative to the
camera.

I wonder, if I fed the lamps with mains voltage DC, simply a bridge
rectifier and a huge capacitor, they'd reduce their flicker.

Wont work at all if they use capacitor droppers and

I made a few of those to power LEDs to indicate the function of my
central heating.  I'm looking inside the flickery lamp just now (Ł15,
20W).  Without undoing the glue holding the PSU onto the inside of it,
all I can see is probably: the mains going through a large bipolar cap,
a tiny resistor (to discharge it safely?), a bridge rectifier, another
very large resister (to limit the LED current more accurately?), then a
400V 4.7uF capacitor (which is bulged).  A capacitor dropper with a
rectifier and smoothing capacitor after it?  The one I made has no
smoothing cap, just mains to cap to resistor to bridge to LED.  Perhaps
this bulged cap is why I'm getting flicker, I'll try replacing it
tomorrow.

they very likely do because those are the only cheap
droppers for dropping such a large voltage.

Aren't miniature SMPS units pretty cheap?  I just bought a 12V 6A SMPS
for Ł4.50.  Designed for powering LEDs - but I've looked inside it and
it's definitely a switched mode, not a capacitor dropper.  Now this
flickery LED lamp I'm looking inside, it's about 20W, so 12V at 2A is
all that's required, it could have had an SMPS in it similar to the one
I just described.

I'm now looking inside one of the better LED lamps (the non-flickery
model).  It has a basic SMPS inside it.  They're 9W and Ł4 each for the
whole lamp.  I'm sure it's more than just a standard SMPS though,
because when some LEDs fail short circuit (it has about 40 in series),
the voltage coming from the PSU drops, to maintain the correct current
for the remaining good LEDs.

Very easy to try tho and see if it works.

Looks like it would help the better ones, but not the crap one.  Better
(as I only have a few crap ones) to stick a bigger smoothing cap inside
those.  For the good ones, the only problem I can foresee with the
external smoother, is overloading the lamp's bridge rectifier, as it
will only be conducting on two of the four diodes.

The cheap shit LED lamp I have that actually flashes at 100Hz would
most
likely get much brighter and burn out, so I'd have to adjust that,
but the
others which only flicker 8% would just get 4% brighter.

you could use being 4 % brighter

That would make my IQ 140.

Was the above too difficult for you to discuss?

I Q's are the lamest oldest forgotten tests of them all ,
are you excited this is going to be how usenet is for you for the next
20 - 30 years

 

[Rod Speed]

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub8lqzpo5piw3@desktop-ga2mpl8.lan...

On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zubnqbkho5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn
jon.fairbairn@cl.cam.ac.uk> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> writes:
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.

Try a longer exposure and move the light rapidly relative to the
camera.

I wonder, if I fed the lamps with mains voltage DC, simply a bridge
rectifier and a huge capacitor, they'd reduce their flicker.

Wont work at all if they use capacitor droppers and

I made a few of those to power LEDs to indicate the function of my central
heating. I'm looking inside the flickery lamp just now (Ł15, 20W).
Without undoing the glue holding the PSU onto the inside of it, all I can
see is probably: the mains going through a large bipolar cap, a tiny
resistor (to discharge it safely?), a bridge rectifier, another very large
resister (to limit the LED current more accurately?), then a 400V 4.7uF
capacitor (which is bulged).

A capacitor dropper with a rectifier and smoothing capacitor after it?

Yep, that's what it is.

The one I made has no smoothing cap, just mains to cap to resistor to
bridge to LED.

Yeah, not need for one if you don't mind the 100Hz flicker.

Perhaps this bulged cap is why I'm getting flicker, I'll try replacing it
tomorrow.

they very likely do because those are the only cheap
droppers for dropping such a large voltage.

Aren't miniature SMPS units pretty cheap?

Not as cheap as the cap and the bridge rectifier.

> I just bought a 12V 6A SMPS for Ł4.50.

Yeah, I did too.

> Designed for powering LEDs

Mine will run anything 12V. I currently use it to power a water pump.

The LEDs I use are all Hues and have their
own power supply with the led strips.

- but I've looked inside it and it's definitely a switched mode, not a
capacitor dropper. Now this flickery LED lamp I'm looking inside, it's
about 20W, so 12V at 2A is all that's required, it could have had an SMPS
in it similar to the one I just described.

Yeah, but the cap and bridge are cheaper.

I'm now looking inside one of the better LED lamps (the non-flickery
model). It has a basic SMPS inside it. They're 9W and Ł4 each for the
whole lamp. I'm sure it's more than just a standard SMPS though, because
when some LEDs fail short circuit (it has about 40 in series), the voltage
coming from the PSU drops, to maintain the correct current for the
remaining good LEDs.

Yeah, its best to drive leds in constant current mode.

Very easy to try tho and see if it works.

Looks like it would help the better ones, but not the crap one.

In fact capacitor dropper ones wont work at all when fed DC.

Better (as I only have a few crap ones) to stick a bigger smoothing cap
inside those.

Yep as long as it will fit.

For the good ones, the only problem I can foresee with the external
smoother, is overloading the lamp's bridge rectifier, as it will only be
conducting on two of the four diodes.

Should still be fine, most bridges in that situation are used
very conservitably and the diodes are rated for the initial
turn on surge current.

The cheap shit LED lamp I have that actually flashes at 100Hz would most
likely get much brighter and burn out, so I'd have to adjust that, but
the
others which only flicker 8% would just get 4% brighter.

 

[William Gothberg]

On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed <rod.speed.aaa@gmail.com> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd <not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get enough
brightness out of LEDs that fit into the lamp holder. The LEDs would
get too hot trying to give out enough brightness for a car headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye). Perhaps they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or you're in
a
country that uses different car lights than here in the USA. There
are a lot of cars with LED lighting, headlights and rear lights, and
I've never noticed this flickering, nor have I ever heard it mentioned
before this thread. I haven't noticed flickering from any LED lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done. Nor have I
heard anyone else mention it. Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything. If just
scanning reveals it, you;d think a lot of people would be noticing it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

Er.... most people I know can see fluorescent flicker. It doesn't annoy most of them, but they can detect it. One in five people I know could see 60Hz monitor flickering. And about the same can see car lights flickering.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

You must know some people with really shitty eyesight. I noticed that more people who were younger and/or didn't wear specs could see the flicker.

Don't most cars have LEDs now? Or does your area have a lot of older
cars? People (stupidly) around here seem to like cars that are no more
than 10 years old. I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

 

[%]

On 2018-12-20 2:38 p.m., William Gothberg wrote:

On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd
not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power  into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the
risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get enough
brightness out of LEDs that fit into the lamp holder.  The LEDs
would
get too hot trying to give out enough brightness for a car
headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye).  Perhaps they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or
you're in
a
country that uses different car lights than here in the USA.  There
are a lot of cars with LED lighting, headlights and rear lights, and
I've never noticed this flickering, nor have I ever heard it
mentioned
before this thread.  I haven't noticed flickering from any LED
lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done.  Nor have I
heard anyone else mention it.  Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything.  If just
scanning reveals it, you;d think a lot of people would be noticing it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

Er.... most people I know can see fluorescent flicker.  It doesn't annoy
most of them, but they can detect it.  One in five people I know could
see 60Hz monitor flickering.  And about the same can see car lights
flickering.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

You must know some people with really shitty eyesight.  I noticed that
more people who were younger and/or didn't wear specs could see the
flicker.

Don't most cars have LEDs now?  Or does your area have a lot of older
cars?  People (stupidly) around here seem to like cars that are no more
than 10 years old.  I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

the same thing happens when i type your name and add the words gutless idgit

 

[Peeler]

On Fri, 21 Dec 2018 08:50:21 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:


> I'm talking about everyone at work. NOT ONE could see that.

ROTFLOL! You have no work, you unemployable, 85-year-old, decrepit senile
troll! ONLY people you could talk to (but they OBVIOUSLY refuse to talk to
you) are your room mates in your old people's home! LOL

--
Marland addressing bullshitting senile Rot:
"Stay in your wet paper bag you thick twit."
MID: <fv9f8uFcc0uU1@mid.individual.net>

 

[Rod Speed]

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zucc6l1ao5piw3@desktop-ga2mpl8.lan...

On Thu, 20 Dec 2018 21:50:21 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zucbp2igo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William
Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd
not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the
risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get
enough
brightness out of LEDs that fit into the lamp holder. The LEDs
would
get too hot trying to give out enough brightness for a car
headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye). Perhaps
they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or you're
in
a
country that uses different car lights than here in the USA.
There
are a lot of cars with LED lighting, headlights and rear lights,
and
I've never noticed this flickering, nor have I ever heard it
mentioned
before this thread. I haven't noticed flickering from any LED
lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done. Nor have
I
heard anyone else mention it. Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything. If just
scanning reveals it, you;d think a lot of people would be noticing
it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

Er.... most people I know can see fluorescent flicker. It doesn't annoy
most of them, but they can detect it.

Don't believe it. I did have someone at work who could
see it and was asking about how to get it fixed but no
one else could see what she was talking about.

About 20 years ago I worked where everyone had a cheap 14" CRT monitor
running at 60Hz. They really bugged me with the flicker. When I asked
everyone about them, 80% couldn't see it, 10% said they were as annoyed as
me, and 10% only saw it if they looked for it. For the 10% and the 10%, I
bought some nice 90Hz Iiyama Vision Master Pro CRT monitors. They
absolutely loved them. The other 80% couldn't see what the fuss was
about, and most of them had specs or were older.

One in five people I know could see 60Hz monitor flickering.

Don't believe that either and I never had anyone complaining about it.

And about the same can see car lights flickering.

Don't believe that either and clearly the designers can't.

A quick google search shows many many people don't like car flicker.
Millions of results.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

You must know some people with really shitty eyesight.

I'm talking about everyone at work. NOT ONE could see that.

What age group were they in?

All of the, everything from those straight out
of school to those who were about to retire.
And the kids of many of them as well.

I noticed that more people who were younger and/or didn't wear specs
could
see the flicker.

Don't buy that either. None of the kids could see it.

Even a colleague who never noticed it before when he looked at one of the
new 90Hz monitors immediately remarked "that picture's really stable!"

Don't most cars have LEDs now? Or does your area have a lot of older
cars? People (stupidly) around here seem to like cars that are no
more
than 10 years old. I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

 

[Peeler]

On Fri, 21 Dec 2018 08:04:01 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

Good Lord! Is this still about flickering lights, you fucking stupid idiots?

--
Richard addressing Rot Speed:
"Shit you're thick/pathetic excuse for a troll."
MID: <ogoa38$pul$1@news.mixmin.net>

 

[Rod Speed]

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zucb6od6o5piw3@desktop-ga2mpl8.lan...

On Thu, 20 Dec 2018 21:35:49 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub8lqzpo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zubnqbkho5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn
jon.fairbairn@cl.cam.ac.uk> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> writes:
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.

Try a longer exposure and move the light rapidly relative to the
camera.

I wonder, if I fed the lamps with mains voltage DC, simply a bridge
rectifier and a huge capacitor, they'd reduce their flicker.

Wont work at all if they use capacitor droppers and

I made a few of those to power LEDs to indicate the function of my
central
heating. I'm looking inside the flickery lamp just now (Ł15, 20W).
Without undoing the glue holding the PSU onto the inside of it, all I
can
see is probably: the mains going through a large bipolar cap, a tiny
resistor (to discharge it safely?), a bridge rectifier, another very
large
resister (to limit the LED current more accurately?), then a 400V 4.7uF
capacitor (which is bulged).

A capacitor dropper with a rectifier and smoothing capacitor after it?

Yep, that's what it is.

The one I made has no smoothing cap, just mains to cap to resistor to
bridge to LED.

Yeah, not need for one if you don't mind the 100Hz flicker.

It was just indicator LEDs to tell me what water circuit was running. 3
zones from the one boiler switched with valves.

Perhaps this bulged cap is why I'm getting flicker, I'll try replacing
it
tomorrow.

they very likely do because those are the only cheap
droppers for dropping such a large voltage.

Aren't miniature SMPS units pretty cheap?

Not as cheap as the cap and the bridge rectifier.

I just bought a 12V 6A SMPS for Ł4.50.

Yeah, I did too.

Designed for powering LEDs

Mine will run anything 12V. I currently use it to power a water pump.

It was sold for LEDs, presumably it will run anything provided I don't
exceed the 6A.

However I've noticed they scrimp on the caps (or cooling). Loads of them
get bulged caps after a while, in particular a 3A PSU I ran 2A of LEDs
24/7 from, failed in 1 year. It kept cutting out - I discovered the bulk
capacitor had dried out. Same happened (over a longer period) with two
monitor PSUs.

The LEDs I use are all Hues and have their
own power supply with the led strips.

The one I mentioned above was for an insectocuter, I removed the flours
and ballast and fitted strips of UV LEDs instead.

- but I've looked inside it and it's definitely a switched mode, not a
capacitor dropper. Now this flickery LED lamp I'm looking inside, it's
about 20W, so 12V at 2A is all that's required, it could have had an
SMPS
in it similar to the one I just described.

Yeah, but the cap and bridge are cheaper.

Well I've got 9W Ł4 strips with a switched mode PSU in them, so they can't
cost that much.

I'm now looking inside one of the better LED lamps (the non-flickery
model). It has a basic SMPS inside it. They're 9W and Ł4 each for the
whole lamp. I'm sure it's more than just a standard SMPS though,
because
when some LEDs fail short circuit (it has about 40 in series), the
voltage
coming from the PSU drops, to maintain the correct current for the
remaining good LEDs.

Yeah, its best to drive leds in constant current mode.

I'm surprised that the LEDs always fail short circuit, new type of LED
designed to do this?

Think its just the way leds fail naturally
with the higher powered lighting leds.

And I think the LED failures are due to heat. I now run them with the
diffuser covers off to let them be cooler. I get more light out of them
too, and I think they look better when you can see all the dots.

I'm not rapt in that result with the led strips,
particularly with the reflection off glass etc.
I havent gotten around to mounting them
properly yet, mainly because for some
reason Bunnings doesn't stock the
extrusions to mount them in in the
very long 3-4M strips and those arent
feasible to buy online in those lengths.
Bit too crude imo to have a series of 1M ones.

I do plan to have diffusers for those led
strips to fix the bright reflection of the
individual leds off the glass like the
front of the microwaves and wall oven
and windows.

Very easy to try tho and see if it works.

Looks like it would help the better ones, but not the crap one.

In fact capacitor dropper ones wont work at all when fed DC.

Agreed.

Better (as I only have a few crap ones) to stick a bigger smoothing cap
inside those.

Yep as long as it will fit.

They're huge inside, massive space. "Corn on the cob LED lights" they're
called.

I don't use those, use the Hue E27 bulbs.

I could literally fit a cap about 50 times the size of the one that's in
it. It's probably enough smoothing with the original size, I can't
remember if it flickered when I bought it. But clearly the cap was
overworked as it failed, so I'll fit something larger so it lasts longer
this time.

Might well just be a low quality cap, not over worked.
Rectifier caps don't get overworked when not enough uF.

For the good ones, the only problem I can foresee with the external
smoother, is overloading the lamp's bridge rectifier, as it will only be
conducting on two of the four diodes.

Should still be fine, most bridges in that situation are used
very conservitably and the diodes are rated for the initial
turn on surge current.

There's a current limiting resistor before them.

But the current rating would be vastly lower than the surge rating.

If I was to go ahead, I think I'd run one on the bench and check the
temperature of the diodes in normal operation.

They'll be fine at that current.

If they're not very warm then they won't mind double the current.

Don't those diodes handle surges anyway?

Yeah, the surge rating is massive.

> I mean a 3A diode will take way more than that for a fraction of a second.

Yep.

> It's the heat that kills them.

Not with bridges.

> So why don't they just fit what they need to instead of bigger ones?

The bigger ones are the same price.

Its only when you got to the big ones
potted in a square aluminium thing with
a bolt hole in them that the price increases.

 

[William Gothberg]

On Thu, 20 Dec 2018 21:50:21 -0000, Rod Speed <rod.speed.aaa@gmail.com> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zucbp2igo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd
not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the
risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get enough
brightness out of LEDs that fit into the lamp holder. The LEDs
would
get too hot trying to give out enough brightness for a car
headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye). Perhaps they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or you're
in
a
country that uses different car lights than here in the USA. There
are a lot of cars with LED lighting, headlights and rear lights, and
I've never noticed this flickering, nor have I ever heard it
mentioned
before this thread. I haven't noticed flickering from any LED
lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done. Nor have I
heard anyone else mention it. Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything. If just
scanning reveals it, you;d think a lot of people would be noticing it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

Er.... most people I know can see fluorescent flicker. It doesn't annoy
most of them, but they can detect it.

Don't believe it. I did have someone at work who could
see it and was asking about how to get it fixed but no
one else could see what she was talking about.

About 20 years ago I worked where everyone had a cheap 14" CRT monitor running at 60Hz. They really bugged me with the flicker. When I asked everyone about them, 80% couldn't see it, 10% said they were as annoyed as me, and 10% only saw it if they looked for it. For the 10% and the 10%, I bought some nice 90Hz Iiyama Vision Master Pro CRT monitors. They absolutely loved them. The other 80% couldn't see what the fuss was about, and most of them had specs or were older.

One in five people I know could see 60Hz monitor flickering.

Don't believe that either and I never had anyone complaining about it.

And about the same can see car lights flickering.

Don't believe that either and clearly the designers can't.

A quick google search shows many many people don't like car flicker. Millions of results.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

You must know some people with really shitty eyesight.

I'm talking about everyone at work. NOT ONE could see that.

What age group were they in?

I noticed that more people who were younger and/or didn't wear specs could
see the flicker.

Don't buy that either. None of the kids could see it.

Even a colleague who never noticed it before when he looked at one of the new 90Hz monitors immediately remarked "that picture's really stable!"

Don't most cars have LEDs now? Or does your area have a lot of older
cars? People (stupidly) around here seem to like cars that are no more
than 10 years old. I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

 

[%]

On 2018-12-20 2:48 p.m., William Gothberg wrote:

On Thu, 20 Dec 2018 21:25:45 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 1:56 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 20:40:26 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 1:30 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed
rod.speed.aaa@gmail.com
wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in
message
newsp.zubnqbkho5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn
jon.fairbairn@cl.cam.ac.uk> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> writes:
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.

Try a longer exposure and move the light rapidly relative to the
camera.

I wonder, if I fed the lamps with mains voltage DC, simply a bridge
rectifier and a huge capacitor, they'd reduce their flicker.

Wont work at all if they use capacitor droppers and

I made a few of those to power LEDs to indicate the function of my
central heating.  I'm looking inside the flickery lamp just now (Ł15,
20W).  Without undoing the glue holding the PSU onto the inside of it,
all I can see is probably: the mains going through a large bipolar
cap,
a tiny resistor (to discharge it safely?), a bridge rectifier, another
very large resister (to limit the LED current more accurately?),
then a
400V 4.7uF capacitor (which is bulged).  A capacitor dropper with a
rectifier and smoothing capacitor after it?  The one I made has no
smoothing cap, just mains to cap to resistor to bridge to LED.
Perhaps
this bulged cap is why I'm getting flicker, I'll try replacing it
tomorrow.

they very likely do because those are the only cheap
droppers for dropping such a large voltage.

Aren't miniature SMPS units pretty cheap?  I just bought a 12V 6A SMPS
for Ł4.50.  Designed for powering LEDs - but I've looked inside it and
it's definitely a switched mode, not a capacitor dropper.  Now this
flickery LED lamp I'm looking inside, it's about 20W, so 12V at 2A is
all that's required, it could have had an SMPS in it similar to the
one
I just described.

I'm now looking inside one of the better LED lamps (the non-flickery
model).  It has a basic SMPS inside it.  They're 9W and Ł4 each for
the
whole lamp.  I'm sure it's more than just a standard SMPS though,
because when some LEDs fail short circuit (it has about 40 in series),
the voltage coming from the PSU drops, to maintain the correct current
for the remaining good LEDs.

Very easy to try tho and see if it works.

Looks like it would help the better ones, but not the crap one.
Better
(as I only have a few crap ones) to stick a bigger smoothing cap
inside
those.  For the good ones, the only problem I can foresee with the
external smoother, is overloading the lamp's bridge rectifier, as it
will only be conducting on two of the four diodes.

The cheap shit LED lamp I have that actually flashes at 100Hz would
most
likely get much brighter and burn out, so I'd have to adjust that,
but the
others which only flicker 8% would just get 4% brighter.

you could use being 4 % brighter

That would make my IQ 140.

Was the above too difficult for you to discuss?

I Q's are the lamest oldest forgotten tests of them all ,

You're just jealous.

are you excited this is going to be how usenet is for you for the next
20 - 30 years

Be more specific.

no and start getting used to the idea that i don't do what you order

 

[%]

On 2018-12-20 2:48 p.m., William Gothberg wrote:

On Thu, 20 Dec 2018 21:40:48 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 2:38 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William
Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd
not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power  into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the
risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get
enough
brightness out of LEDs that fit into the lamp holder.  The LEDs
would
get too hot trying to give out enough brightness for a car
headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye).  Perhaps
they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or
you're in
a
country that uses different car lights than here in the USA.
There
are a lot of cars with LED lighting, headlights and rear
lights, and
I've never noticed this flickering, nor have I ever heard it
mentioned
before this thread.  I haven't noticed flickering from any LED
lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done.  Nor
have I
heard anyone else mention it.  Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything.  If just
scanning reveals it, you;d think a lot of people would be noticing
it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

Er.... most people I know can see fluorescent flicker.  It doesn't annoy
most of them, but they can detect it.  One in five people I know could
see 60Hz monitor flickering.  And about the same can see car lights
flickering.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

You must know some people with really shitty eyesight.  I noticed that
more people who were younger and/or didn't wear specs could see the
flicker.

Don't most cars have LEDs now?  Or does your area have a lot of older
cars?  People (stupidly) around here seem to like cars that are no
more
than 10 years old.  I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

the same thing happens when i type your name and add the words gutless
idgit

Cite link.

you don't know how to type your name , come off it

 

[%]

On 2018-12-20 2:48 p.m., William Gothberg wrote:

On Thu, 20 Dec 2018 21:35:49 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub8lqzpo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zubnqbkho5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn
jon.fairbairn@cl.cam.ac.uk> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> writes:
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.

Try a longer exposure and move the light rapidly relative to the
camera.

I wonder, if I fed the lamps with mains voltage DC, simply a bridge
rectifier and a huge capacitor, they'd reduce their flicker.

Wont work at all if they use capacitor droppers and

I made a few of those to power LEDs to indicate the function of my
central
heating.  I'm looking inside the flickery lamp just now (Ł15, 20W).
Without undoing the glue holding the PSU onto the inside of it, all I
can
see is probably: the mains going through a large bipolar cap, a tiny
resistor (to discharge it safely?), a bridge rectifier, another very
large
resister (to limit the LED current more accurately?), then a 400V 4.7uF
capacitor (which is bulged).

A capacitor dropper with a rectifier and smoothing capacitor after it?

Yep, that's what it is.

The one I made has no smoothing cap, just mains to cap to resistor to
bridge to LED.

Yeah, not need for one if you don't mind the 100Hz flicker.

It was just indicator LEDs to tell me what water circuit was running.  3
zones from the one boiler switched with valves.

Perhaps this bulged cap is why I'm getting flicker, I'll try
replacing it
tomorrow.

they very likely do because those are the only cheap
droppers for dropping such a large voltage.

Aren't miniature SMPS units pretty cheap?

Not as cheap as the cap and the bridge rectifier.

I just bought a 12V 6A SMPS for Ł4.50.

Yeah, I did too.

Designed for powering LEDs

Mine will run anything 12V. I currently use it to power a water pump.

It was sold for LEDs, presumably it will run anything provided I don't
exceed the 6A.

However I've noticed they scrimp on the caps (or cooling).  Loads of
them get bulged caps after a while, in particular a 3A PSU I ran 2A of
LEDs 24/7 from, failed in 1 year.  It kept cutting out - I discovered
the bulk capacitor had dried out.  Same happened (over a longer period)
with two monitor PSUs.

The LEDs I use are all Hues and have their
own power supply with the led strips.

The one I mentioned above was for an insectocuter, I removed the flours
and ballast and fitted strips of UV LEDs instead.

- but I've looked inside it and it's definitely a switched mode, not a
capacitor dropper.  Now this flickery LED lamp I'm looking inside, it's
about 20W, so 12V at 2A is all that's required, it could have had an
SMPS
in it similar to the one I just described.

Yeah, but the cap and bridge are cheaper.

Well I've got 9W Ł4 strips with a switched mode PSU in them, so they
can't cost that much.

I'm now looking inside one of the better LED lamps (the non-flickery
model).  It has a basic SMPS inside it.  They're 9W and Ł4 each for the
whole lamp.  I'm sure it's more than just a standard SMPS though,
because
when some LEDs fail short circuit (it has about 40 in series), the
voltage
coming from the PSU drops, to maintain the correct current for the
remaining good LEDs.

Yeah, its best to drive leds in constant current mode.

I'm surprised that the LEDs always fail short circuit, new type of LED
designed to do this?

And I think the LED failures are due to heat.  I now run them with the
diffuser covers off to let them be cooler.  I get more light out of them
too, and I think they look better when you can see all the dots.

Very easy to try tho and see if it works.

Looks like it would help the better ones, but not the crap one.

In fact capacitor dropper ones wont work at all when fed DC.

Agreed.

Better (as I only have a few crap ones) to stick a bigger smoothing cap
inside those.

Yep as long as it will fit.

They're huge inside, massive space.  "Corn on the cob LED lights"
they're called.  I could literally fit a cap about 50 times the size of
the one that's in it.  It's probably enough smoothing with the original
size, I can't remember if it flickered when I bought it.  But clearly
the cap was overworked as it failed, so I'll fit something larger so it
lasts longer this time.

For the good ones, the only problem I can foresee with the external
smoother, is overloading the lamp's bridge rectifier, as it will only be
conducting on two of the four diodes.

Should still be fine, most bridges in that situation are used
very conservitably and the diodes are rated for the initial
turn on surge current.

There's a current limiting resistor before them.

If I was to go ahead, I think I'd run one on the bench and check the
temperature of the diodes in normal operation.  If they're not very warm
then they won't mind double the current.

Don't those diodes handle surges anyway?  I mean a 3A diode will take
way more than that for a fraction of a second.  It's the heat that kills
them.  So why don't they just fit what they need to instead of bigger ones?

trimmers , you need trimmers

 

[Rod Speed]

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zucbp2igo5piw3@desktop-ga2mpl8.lan...

On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd
not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the
risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get enough
brightness out of LEDs that fit into the lamp holder. The LEDs
would
get too hot trying to give out enough brightness for a car
headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye). Perhaps they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or you're
in
a
country that uses different car lights than here in the USA. There
are a lot of cars with LED lighting, headlights and rear lights, and
I've never noticed this flickering, nor have I ever heard it
mentioned
before this thread. I haven't noticed flickering from any LED
lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done. Nor have I
heard anyone else mention it. Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything. If just
scanning reveals it, you;d think a lot of people would be noticing it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

Er.... most people I know can see fluorescent flicker. It doesn't annoy
most of them, but they can detect it.

Don't believe it. I did have someone at work who could
see it and was asking about how to get it fixed but no
one else could see what she was talking about.

> One in five people I know could see 60Hz monitor flickering.

Don't believe that either and I never had anyone complaining about it.

> And about the same can see car lights flickering.

Don't believe that either and clearly the designers can't.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

You must know some people with really shitty eyesight.

I'm talking about everyone at work. NOT ONE could see that.

I noticed that more people who were younger and/or didn't wear specs could
see the flicker.

Don't buy that either. None of the kids could see it.

Don't most cars have LEDs now? Or does your area have a lot of older
cars? People (stupidly) around here seem to like cars that are no more
than 10 years old. I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

 

[William Gothberg]

On Thu, 20 Dec 2018 21:25:45 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 1:56 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 20:40:26 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 1:30 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zubnqbkho5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn
jon.fairbairn@cl.cam.ac.uk> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> writes:
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.

Try a longer exposure and move the light rapidly relative to the
camera.

I wonder, if I fed the lamps with mains voltage DC, simply a bridge
rectifier and a huge capacitor, they'd reduce their flicker.

Wont work at all if they use capacitor droppers and

I made a few of those to power LEDs to indicate the function of my
central heating. I'm looking inside the flickery lamp just now (Ł15,
20W). Without undoing the glue holding the PSU onto the inside of it,
all I can see is probably: the mains going through a large bipolar cap,
a tiny resistor (to discharge it safely?), a bridge rectifier, another
very large resister (to limit the LED current more accurately?), then a
400V 4.7uF capacitor (which is bulged). A capacitor dropper with a
rectifier and smoothing capacitor after it? The one I made has no
smoothing cap, just mains to cap to resistor to bridge to LED. Perhaps
this bulged cap is why I'm getting flicker, I'll try replacing it
tomorrow.

they very likely do because those are the only cheap
droppers for dropping such a large voltage.

Aren't miniature SMPS units pretty cheap? I just bought a 12V 6A SMPS
for Ł4.50. Designed for powering LEDs - but I've looked inside it and
it's definitely a switched mode, not a capacitor dropper. Now this
flickery LED lamp I'm looking inside, it's about 20W, so 12V at 2A is
all that's required, it could have had an SMPS in it similar to the one
I just described.

I'm now looking inside one of the better LED lamps (the non-flickery
model). It has a basic SMPS inside it. They're 9W and Ł4 each for the
whole lamp. I'm sure it's more than just a standard SMPS though,
because when some LEDs fail short circuit (it has about 40 in series),
the voltage coming from the PSU drops, to maintain the correct current
for the remaining good LEDs.

Very easy to try tho and see if it works.

Looks like it would help the better ones, but not the crap one. Better
(as I only have a few crap ones) to stick a bigger smoothing cap inside
those. For the good ones, the only problem I can foresee with the
external smoother, is overloading the lamp's bridge rectifier, as it
will only be conducting on two of the four diodes.

The cheap shit LED lamp I have that actually flashes at 100Hz would
most
likely get much brighter and burn out, so I'd have to adjust that,
but the
others which only flicker 8% would just get 4% brighter.

you could use being 4 % brighter

That would make my IQ 140.

Was the above too difficult for you to discuss?

I Q's are the lamest oldest forgotten tests of them all ,

You're just jealous.

are you excited this is going to be how usenet is for you for the next
20 - 30 years

Be more specific.

 

[William Gothberg]

On Thu, 20 Dec 2018 21:40:48 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 2:38 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd
not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the
risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get enough
brightness out of LEDs that fit into the lamp holder. The LEDs
would
get too hot trying to give out enough brightness for a car
headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye). Perhaps they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or
you're in
a
country that uses different car lights than here in the USA. There
are a lot of cars with LED lighting, headlights and rear lights, and
I've never noticed this flickering, nor have I ever heard it
mentioned
before this thread. I haven't noticed flickering from any LED
lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done. Nor have I
heard anyone else mention it. Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything. If just
scanning reveals it, you;d think a lot of people would be noticing it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

Er.... most people I know can see fluorescent flicker. It doesn't annoy
most of them, but they can detect it. One in five people I know could
see 60Hz monitor flickering. And about the same can see car lights
flickering.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

You must know some people with really shitty eyesight. I noticed that
more people who were younger and/or didn't wear specs could see the
flicker.

Don't most cars have LEDs now? Or does your area have a lot of older
cars? People (stupidly) around here seem to like cars that are no more
than 10 years old. I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

the same thing happens when i type your name and add the words gutless idgit

Cite link.

 

[William Gothberg]

On Thu, 20 Dec 2018 21:35:49 -0000, Rod Speed <rod.speed.aaa@gmail.com> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub8lqzpo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zubnqbkho5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn
jon.fairbairn@cl.cam.ac.uk> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> writes:
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.

Try a longer exposure and move the light rapidly relative to the
camera.

I wonder, if I fed the lamps with mains voltage DC, simply a bridge
rectifier and a huge capacitor, they'd reduce their flicker.

Wont work at all if they use capacitor droppers and

I made a few of those to power LEDs to indicate the function of my central
heating. I'm looking inside the flickery lamp just now (Ł15, 20W).
Without undoing the glue holding the PSU onto the inside of it, all I can
see is probably: the mains going through a large bipolar cap, a tiny
resistor (to discharge it safely?), a bridge rectifier, another very large
resister (to limit the LED current more accurately?), then a 400V 4.7uF
capacitor (which is bulged).

A capacitor dropper with a rectifier and smoothing capacitor after it?

Yep, that's what it is.

The one I made has no smoothing cap, just mains to cap to resistor to
bridge to LED.

Yeah, not need for one if you don't mind the 100Hz flicker.

It was just indicator LEDs to tell me what water circuit was running. 3 zones from the one boiler switched with valves.

Perhaps this bulged cap is why I'm getting flicker, I'll try replacing it
tomorrow.

they very likely do because those are the only cheap
droppers for dropping such a large voltage.

Aren't miniature SMPS units pretty cheap?

Not as cheap as the cap and the bridge rectifier.

I just bought a 12V 6A SMPS for Ł4.50.

Yeah, I did too.

Designed for powering LEDs

Mine will run anything 12V. I currently use it to power a water pump.

It was sold for LEDs, presumably it will run anything provided I don't exceed the 6A.

However I've noticed they scrimp on the caps (or cooling). Loads of them get bulged caps after a while, in particular a 3A PSU I ran 2A of LEDs 24/7 from, failed in 1 year. It kept cutting out - I discovered the bulk capacitor had dried out. Same happened (over a longer period) with two monitor PSUs.

The LEDs I use are all Hues and have their
own power supply with the led strips.

The one I mentioned above was for an insectocuter, I removed the flours and ballast and fitted strips of UV LEDs instead.

- but I've looked inside it and it's definitely a switched mode, not a
capacitor dropper. Now this flickery LED lamp I'm looking inside, it's
about 20W, so 12V at 2A is all that's required, it could have had an SMPS
in it similar to the one I just described.

Yeah, but the cap and bridge are cheaper.

Well I've got 9W Ł4 strips with a switched mode PSU in them, so they can't cost that much.

I'm now looking inside one of the better LED lamps (the non-flickery
model). It has a basic SMPS inside it. They're 9W and Ł4 each for the
whole lamp. I'm sure it's more than just a standard SMPS though, because
when some LEDs fail short circuit (it has about 40 in series), the voltage
coming from the PSU drops, to maintain the correct current for the
remaining good LEDs.

Yeah, its best to drive leds in constant current mode.

I'm surprised that the LEDs always fail short circuit, new type of LED designed to do this?

And I think the LED failures are due to heat. I now run them with the diffuser covers off to let them be cooler. I get more light out of them too, and I think they look better when you can see all the dots.

Very easy to try tho and see if it works.

Looks like it would help the better ones, but not the crap one.

In fact capacitor dropper ones wont work at all when fed DC.

Agreed.

Better (as I only have a few crap ones) to stick a bigger smoothing cap
inside those.

Yep as long as it will fit.

They're huge inside, massive space. "Corn on the cob LED lights" they're called. I could literally fit a cap about 50 times the size of the one that's in it. It's probably enough smoothing with the original size, I can't remember if it flickered when I bought it. But clearly the cap was overworked as it failed, so I'll fit something larger so it lasts longer this time.

For the good ones, the only problem I can foresee with the external
smoother, is overloading the lamp's bridge rectifier, as it will only be
conducting on two of the four diodes.

Should still be fine, most bridges in that situation are used
very conservitably and the diodes are rated for the initial
turn on surge current.

There's a current limiting resistor before them.

If I was to go ahead, I think I'd run one on the bench and check the temperature of the diodes in normal operation. If they're not very warm then they won't mind double the current.

Don't those diodes handle surges anyway? I mean a 3A diode will take way more than that for a fraction of a second. It's the heat that kills them. So why don't they just fit what they need to instead of bigger ones?

 

[Peeler]

On Fri, 21 Dec 2018 08:35:49 +1100, cantankerous trolling geezer Rot Speed,
the auto-contradicting senile sociopath, blabbered, again:

<FLUSH all the unbelievably idiotic drivel by the two prize idiots>

....and nothing's left!

--
MrTurnip@down.the.farm about senile Rot Speed:
"This is like having a conversation with someone with brain damage."
MID: <ps10v9$uo2$1@gioia.aioe.org>

 

[William Gothberg]

On Thu, 20 Dec 2018 21:52:55 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 2:48 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 21:40:48 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 2:38 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed <rod.speed.aaa@gmail.com
wrote:



"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
newsp.zub0oriqo5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 17:13:52 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 12:07:40 PM UTC-5, William Gothberg
wrote:
On Thu, 20 Dec 2018 16:25:22 -0000, trader_4 <trader4@optonline.net
wrote:

On Thursday, December 20, 2018 at 7:29:53 AM UTC-5, William
Gothberg
wrote:
On Thu, 20 Dec 2018 11:57:01 -0000, whisky-dave
whisky.dave@gmail.com> wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, William Gothberg
wrote:
On Wed, 19 Dec 2018 16:21:41 -0000, Mark Lloyd
not@mail.invalid
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?

It's easy but that isn't the point. The most efficient way of
driving to make maximium power into the LED means yuo have to
pulse the LED's. Using a capcitor to smooth out the DC is yet
another mode of inefficincy as it would get warm due to current
flow. Indictors in series might be better but then you run the
risk
of 'radio' interference.

Being inefficient would presumably make it impossible to get
enough
brightness out of LEDs that fit into the lamp holder. The LEDs
would
get too hot trying to give out enough brightness for a car
headlight.

However cars vary a lot, some are easy to detect flickering, some
difficult, and some impossible (with the naked eye). Perhaps
they
just use a higher frequency?

Taillights are pretty bad on a lot of cars, as they dim the
brakelights by deliberately flickering them.

Either you have eyes that are way more sensitive to this or
you're in
a
country that uses different car lights than here in the USA.
There
are a lot of cars with LED lighting, headlights and rear
lights, and
I've never noticed this flickering, nor have I ever heard it
mentioned
before this thread. I haven't noticed flickering from any LED
lights
I've used either.

I can see flicker on a 60Hz CRT monitor, but not on a 90Hz one, so
that'll give you an idea on how good my eyes are.

Can you see flicker on tailliights if you scan your eyes across the
scene?

Like I said, I haven't noticed it in the driving I've done. Nor
have I
heard anyone else mention it. Next time I come across a car that has
LEDs I'll look more closely and see if I can see anything. If just
scanning reveals it, you;d think a lot of people would be noticing
it.
Scanning is a part of driving.

I'd estimate about 1 in 5 people can see it,

Its nothing like that high and we know that because nothing
like that many saw any flickering with fluorescent lights.

Er.... most people I know can see fluorescent flicker. It doesn't annoy
most of them, but they can detect it. One in five people I know could
see 60Hz monitor flickering. And about the same can see car lights
flickering.

similar to how many can see flicker on a 60Hz CRT computer monitor.

Nothing even remotely like 1 in 5 can see that.

You must know some people with really shitty eyesight. I noticed that
more people who were younger and/or didn't wear specs could see the
flicker.

Don't most cars have LEDs now? Or does your area have a lot of older
cars? People (stupidly) around here seem to like cars that are no
more
than 10 years old. I don't think many cars after 2008 had bulbs.

Searching for "LED tail light flicker" without the quotes in google
produces 4.5 million results!

the same thing happens when i type your name and add the words gutless
idgit

Cite link.

you don't know how to type your name , come off it

Your name is not %

 

[William Gothberg]

On Thu, 20 Dec 2018 21:53:44 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 2:48 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 21:25:45 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 1:56 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 20:40:26 -0000, % <persent@gmail.com> wrote:

On 2018-12-20 1:30 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed
rod.speed.aaa@gmail.com
wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> wrote in
message
newsp.zubnqbkho5piw3@desktop-ga2mpl8.lan...
On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn
jon.fairbairn@cl.cam.ac.uk> wrote:

"William Gothberg" <"William Gothberg"@internet.co.is> writes:
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.

Try a longer exposure and move the light rapidly relative to the
camera.

I wonder, if I fed the lamps with mains voltage DC, simply a bridge
rectifier and a huge capacitor, they'd reduce their flicker.

Wont work at all if they use capacitor droppers and

I made a few of those to power LEDs to indicate the function of my
central heating. I'm looking inside the flickery lamp just now (Ł15,
20W). Without undoing the glue holding the PSU onto the inside of it,
all I can see is probably: the mains going through a large bipolar
cap,
a tiny resistor (to discharge it safely?), a bridge rectifier, another
very large resister (to limit the LED current more accurately?),
then a
400V 4.7uF capacitor (which is bulged). A capacitor dropper with a
rectifier and smoothing capacitor after it? The one I made has no
smoothing cap, just mains to cap to resistor to bridge to LED.
Perhaps
this bulged cap is why I'm getting flicker, I'll try replacing it
tomorrow.

they very likely do because those are the only cheap
droppers for dropping such a large voltage.

Aren't miniature SMPS units pretty cheap? I just bought a 12V 6A SMPS
for Ł4.50. Designed for powering LEDs - but I've looked inside it and
it's definitely a switched mode, not a capacitor dropper. Now this
flickery LED lamp I'm looking inside, it's about 20W, so 12V at 2A is
all that's required, it could have had an SMPS in it similar to the
one
I just described.

I'm now looking inside one of the better LED lamps (the non-flickery
model). It has a basic SMPS inside it. They're 9W and Ł4 each for
the
whole lamp. I'm sure it's more than just a standard SMPS though,
because when some LEDs fail short circuit (it has about 40 in series),
the voltage coming from the PSU drops, to maintain the correct current
for the remaining good LEDs.

Very easy to try tho and see if it works.

Looks like it would help the better ones, but not the crap one.
Better
(as I only have a few crap ones) to stick a bigger smoothing cap
inside
those. For the good ones, the only problem I can foresee with the
external smoother, is overloading the lamp's bridge rectifier, as it
will only be conducting on two of the four diodes.

The cheap shit LED lamp I have that actually flashes at 100Hz would
most
likely get much brighter and burn out, so I'd have to adjust that,
but the
others which only flicker 8% would just get 4% brighter.

you could use being 4 % brighter

That would make my IQ 140.

Was the above too difficult for you to discuss?

I Q's are the lamest oldest forgotten tests of them all ,

You're just jealous.

are you excited this is going to be how usenet is for you for the next
20 - 30 years

Be more specific.

no and start getting used to the idea that i don't do what you order

No point in you telling me something if you won't back it up.