On Thu, 20 Dec 2018 23:57:18 -0000, % wrote:

On 2018-12-20 4:16 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 21:52:55 -0000, % wrote:

On 2018-12-20 2:48 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 21:40:48 -0000, % wrote:

On 2018-12-20 2:38 p.m., William Gothberg wrote:
On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed

wrote:



"William Gothberg" "William wrote in
message
news On Thu, 20 Dec 2018 17:13:52 -0000, trader_4
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

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
wrote:

On Wednesday, 19 December 2018 16:35:05 UTC, 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?

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 ****ty 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 %

yes it is but that's off topic right now ,

No, it's part of a nym you made up.

right now we're talking about your admission you can't spell yours

I have not misspelt it. I used a fake one.