XPost: alt.home.repair, uk.d-i-y
From: rod.speed.aaa@gmail.com
"William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
news:op.zucc6l1ao5piw3@desktop-ga2mpl8.lan...
> On Thu, 20 Dec 2018 21:50:21 -0000, Rod Speed
> wrote:
>
>>
>>
>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
>> news:op.zucbp2igo5piw3@desktop-ga2mpl8.lan...
>>> On Thu, 20 Dec 2018 21:04:01 -0000, Rod Speed
>>> wrote:
>>>
>>>>
>>>>
>>>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
>>>> news:op.zub0oriqo5piw3@desktop-ga2mpl8.lan...
>>>>> 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.
>>
>> 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
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