XPost: alt.home.repair, uk.d-i-y
From: Gothberg"@internet.co.is
On Sat, 22 Dec 2018 21:27:05 -0000, Rod Speed wrote:
>
>
> "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.
The eyes and the brain together have a frame rate. Easily measured.
>>>>>> 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.
I see more than you do. Why buy a 25fps video camera when you can buy a 50fps
video camera?
>>>>>> 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.
It is better to see what is really there. What other things are you missing
in life?
>> 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.
You don't see it because CRTs had phosphors to match the frame rate, they
would stay lit for the 50th of a second between each illumination. Same is
done now with LCDs. Only cheap rubbish TVs and monitors don't match the
phosphor timing with the scan
timing.
--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)
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