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.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.
> 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!
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