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.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.   
      
   >>> 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.   
      
   >>> 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.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)