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.zufy4tjto5piw3@desktop-ga2mpl8.lan...
> On Sat, 22 Dec 2018 02:53:46 -0000, Rod Speed
> wrote:
>
>>
>>
>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
>> news:op.zueh0jeqo5piw3@desktop-ga2mpl8.lan...
>>> On Fri, 21 Dec 2018 23:09:51 -0000, Rod Speed
>>> wrote:
>>>
>>>>
>>>>
>>>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in message
>>>> news:op.zud6g7a4o5piw3@desktop-ga2mpl8.lan...
>>>>> On Thu, 20 Dec 2018 18:55:13 -0000, Rod Speed
>>>>>
>>>>> wrote:
>>>>>
>>>>>>
>>>>>>
>>>>>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in
>>>>>> message
>>>>>> news:op.zubminnfo5piw3@desktop-ga2mpl8.lan...
>>>>>>> On Thu, 20 Dec 2018 08:19:58 -0000, gregz wrote:
>>>>>>>
>>>>>>>> Clare Snyder wrote:
>>>>>>>>> On Wed, 19 Dec 2018 19:34:57 -0000, "William Gothberg" <"William
>>>>>>>>> Gothberg"@internet.co.is> wrote:
>>>>>>>>>
>>>>>>>>>> On Wed, 19 Dec 2018 18:03:19 -0000, Clark W. Griswold
>>>>>>>>>> wrote:
>>>>>>>>>>
>>>>>>>>>>> On 12/19/2018 11:36 AM, William Gothberg wrote:
>>>>>>>>>>>> On Wed, 19 Dec 2018 16:18:29 -0000, Mark Lloyd
>>>>>>>>>>>>
>>>>>>>>>>>> wrote:
>>>>>>>>>>>>
>>>>>>>>>>>>> On 12/19/18 5:23 AM, William Gothberg wrote:
>>>>>>>>>>>>>> Do switch mode power supplies flicker in time with mains?
>>>>>>>>>>>>>> Specifically
>>>>>>>>>>>>>> LED power supplies in commercially available domestic lamps.
>>>>>>>>>>>>>> By
>>>>>>>>>>>>>> in
>>>>>>>>>>>>>> time, I don't mean at the same 50/60Hz, but anchored to it.
>>>>>>>>>>>>>> I.e.
>>>>>>>>>>>>>> if
>>>>>>>>>>>>>> you
>>>>>>>>>>>>>> have several such lamps each with their own built in supply,
>>>>>>>>>>>>>> will
>>>>>>>>>>>>>> they
>>>>>>>>>>>>>> all flicker in time, using the mains frequency to keep them
>>>>>>>>>>>>>> in
>>>>>>>>>>>>>> time, or
>>>>>>>>>>>>>> will they be random, making the room overall not flicker due
>>>>>>>>>>>>>> to
>>>>>>>>>>>>>> them all
>>>>>>>>>>>>>> being random? And is there any way I can test this? I tried
>>>>>>>>>>>>>> taking
>>>>>>>>>>>>>> photos of them, but my camera only goes as fast as 1/2000th
>>>>>>>>>>>>>> of
>>>>>>>>>>>>>> a
>>>>>>>>>>>>>> second,
>>>>>>>>>>>>>> which shows all the lights at the same brightness each time,
>>>>>>>>>>>>>> I
>>>>>>>>>>>>>> suspect
>>>>>>>>>>>>>> the flicker is above 2000Hz.
>>>>>>>>>>>>>
>>>>>>>>>>>>> I once had an audio amplifier with a solar cell rather than a
>>>>>>>>>>>>> microphone
>>>>>>>>>>>>> for the input transducer. This made it possible to listen to
>>>>>>>>>>>>> light.
>>>>>>>>>>>>> The
>>>>>>>>>>>>> sun is steady, incandescent lights (AC powered) hum.
>>>>>>>>>>>>>
>>>>>>>>>>>>> That was 40 years ago. Maybe something like that would work
>>>>>>>>>>>>> today.
>>>>>>>>>>>>
>>>>>>>>>>>> The trouble is I want to compare 2kHz+ from one light with
>>>>>>>>>>>> 2kHz+
>>>>>>>>>>>> from
>>>>>>>>>>>> a neighbouring light and see if they're in sync.
>>>>>>>>>>>
>>>>>>>>>>> Maybe use a dual trace oscilloscope?
>>>>>>>>>>
>>>>>>>>>> Haven't got one unfortunately.
>>>>>>>>>>
>>>>>>>>>>> Since this landed in alt.home.repair, I gotta ask. Do you have
>>>>>>>>>>> single-phase or two-phase?
>>>>>>>>>>
>>>>>>>>>> Single. I'm in the UK.
>>>>>>>>> so 50 Htz - you can almost see an incandescent flicker at that
>>>>>>>>> frequency (at 25 you could)
>>>>>>>>>
>>>>>>>>> (also rules out the previously mentioned "engineer friend")
>>>>>>>>
>>>>>>>> Lights flicker at twice the frequency, once for positive cycle, and
>>>>>>>> once
>>>>>>>> for negative cycle. LEDs only once unles using a bridge rectifier,
>>>>>>>> or
>>>>>>>> steady on using DC. Even though blinking they look normal straight
>>>>>>>> on,
>>>>>>>> my
>>>>>>>> brain says something is wrong
>>>>>>>
>>>>>>> Some brains (or eyes) seem to be faster than others. I can easily
>>>>>>> (and
>>>>>>> annoyingly) see flicker on CRT monitors below 90Hz, others don't
>>>>>>> even
>>>>>>> see
>>>>>>> the 50 or 60Hz ones. I can see flicker on 80% of car LED lights,
>>>>>>> others
>>>>>>> don't see any. Designers really ought to account for those of us
>>>>>>> with
>>>>>>> better eyesight.
>>>>>>
>>>>>> No point in doing that.
>>>>>
>>>>> There is when half the population is capable of seeing it.
>>>>
>>>> Half the population isnt.
>>>
>>> Then you must know a lot of people with fucked eyesight.
>>
>> Nothing fucked about not seeing flicker on car lights.
>
> Your eyes are clearly operating more slowly,
Nope, just a lower flicker fusion threshold
> at a lower frame rate.
Eyes don't have a frame rate.
>>>>> Why only sell things suitable for those with shitty eyesight?
>>>>
>>>> They are actually designed to work fine for all but freaks.
>>>
>>> Why would you call someone with better eyes a freak?
>>
>> Worse eyes when you see flicker with car lights.
>
> No, I see what's really there.
No you don't. Most obviously with higher flicker rates that you don't see
either.
>>>>> If you can't see the flicker that I can, then your eyes aren't as good
>>>>> as mine.
>>>>
>>>> Nothing good about eyes that see flicker everywhere.
>>>
>>> We see what is really there, you don't.
>>
>> Still fucked to have all car lights flicker. You're a freak.
>
> But they are flickering.
But its better not to see that. You're a freak.
> Go film one with a video camera, or just look up a video of one.
I know they flicker, that's irrelevant to
whether it makes any sense to see that.
I don't see any flicker with movies and it makes no sense
to be able to be see the flicker that is certainly there.
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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