XPost: uk.d-i-y, alt.home.repair   
   From: Gothberg"@internet.co.is   
      
   On Thu, 20 Dec 2018 23:56:14 -0000, %  wrote:   
      
   > On 2018-12-20 4:15 p.m., William Gothberg wrote:   
   >> On Thu, 20 Dec 2018 21:53:44 -0000, %  wrote:   
   >>   
   >>> On 2018-12-20 2:48 p.m., William Gothberg wrote:   
   >>>> On Thu, 20 Dec 2018 21:25:45 -0000, %  wrote:   
   >>>>   
   >>>>> On 2018-12-20 1:56 p.m., William Gothberg wrote:   
   >>>>>> On Thu, 20 Dec 2018 20:40:26 -0000, %  wrote:   
   >>>>>>   
   >>>>>>> On 2018-12-20 1:30 p.m., William Gothberg wrote:   
   >>>>>>>> On Thu, 20 Dec 2018 19:11:36 -0000, Rod Speed   
   >>>>>>>>    
   >>>>>>>> wrote:   
   >>>>>>>>   
   >>>>>>>>> "William Gothberg" <"William Gothberg"@internet.co.is> wrote in   
   >>>>>>>>> message   
   >>>>>>>>> news:op.zubnqbkho5piw3@desktop-ga2mpl8.lan...   
   >>>>>>>>>> On Thu, 20 Dec 2018 09:36:02 -0000, Jon Fairbairn   
   >>>>>>>>>>  wrote:   
   >>>>>>>>>>   
   >>>>>>>>>>> "William Gothberg" <"William Gothberg"@internet.co.is> writes:   
   >>>>>>>>>>>> Agreed. All I can detect (with my digital camera) is that   
   >>>>>>>>>>>> one brand of LED light I have flickers about 5 times less   
   >>>>>>>>>>>> (not sure if it's smother or faster) than the others.   
   >>>>>>>>>>>   
   >>>>>>>>>>> Try a longer exposure and move the light rapidly relative to the   
   >>>>>>>>>>> camera.   
   >>>>>>>>>>   
   >>>>>>>>>> I wonder, if I fed the lamps with mains voltage DC, simply a   
   >>>>>>>>>> bridge   
   >>>>>>>>>> rectifier and a huge capacitor, they'd reduce their flicker.   
   >>>>>>>>>   
   >>>>>>>>> Wont work at all if they use capacitor droppers and   
   >>>>>>>>   
   >>>>>>>> I made a few of those to power LEDs to indicate the function of my   
   >>>>>>>> central heating.  I'm looking inside the flickery lamp just now   
   >>>>>>>> (£15,   
   >>>>>>>> 20W).  Without undoing the glue holding the PSU onto the inside   
   >>>>>>>> of it,   
   >>>>>>>> all I can see is probably: the mains going through a large bipolar   
   >>>>>>>> cap,   
   >>>>>>>> a tiny resistor (to discharge it safely?), a bridge rectifier,   
   >>>>>>>> another   
   >>>>>>>> very large resister (to limit the LED current more accurately?),   
   >>>>>>>> then a   
   >>>>>>>> 400V 4.7uF capacitor (which is bulged).  A capacitor dropper with a   
   >>>>>>>> rectifier and smoothing capacitor after it?  The one I made has no   
   >>>>>>>> smoothing cap, just mains to cap to resistor to bridge to LED.   
   >>>>>>>> Perhaps   
   >>>>>>>> this bulged cap is why I'm getting flicker, I'll try replacing it   
   >>>>>>>> tomorrow.   
   >>>>>>>>   
   >>>>>>>>> they very likely do because those are the only cheap   
   >>>>>>>>> droppers for dropping such a large voltage.   
   >>>>>>>>   
   >>>>>>>> Aren't miniature SMPS units pretty cheap?  I just bought a 12V 6A   
   >>>>>>>> SMPS   
   >>>>>>>> for £4.50.  Designed for powering LEDs - but I've looked inside   
   >>>>>>>> it and   
   >>>>>>>> it's definitely a switched mode, not a capacitor dropper.  Now this   
   >>>>>>>> flickery LED lamp I'm looking inside, it's about 20W, so 12V at   
   >>>>>>>> 2A is   
   >>>>>>>> all that's required, it could have had an SMPS in it similar to the   
   >>>>>>>> one   
   >>>>>>>> I just described.   
   >>>>>>>>   
   >>>>>>>> I'm now looking inside one of the better LED lamps (the non-flickery   
   >>>>>>>> model).  It has a basic SMPS inside it.  They're 9W and £4 each for   
   >>>>>>>> the   
   >>>>>>>> whole lamp.  I'm sure it's more than just a standard SMPS though,   
   >>>>>>>> because when some LEDs fail short circuit (it has about 40 in   
   >>>>>>>> series),   
   >>>>>>>> the voltage coming from the PSU drops, to maintain the correct   
   >>>>>>>> current   
   >>>>>>>> for the remaining good LEDs.   
   >>>>>>>>   
   >>>>>>>>> Very easy to try tho and see if it works.   
   >>>>>>>>   
   >>>>>>>> Looks like it would help the better ones, but not the crap one.   
   >>>>>>>> Better   
   >>>>>>>> (as I only have a few crap ones) to stick a bigger smoothing cap   
   >>>>>>>> inside   
   >>>>>>>> those.  For the good ones, the only problem I can foresee with the   
   >>>>>>>> external smoother, is overloading the lamp's bridge rectifier, as it   
   >>>>>>>> will only be conducting on two of the four diodes.   
   >>>>>>>>   
   >>>>>>>>>> The cheap shit LED lamp I have that actually flashes at 100Hz   
   >>>>>>>>>> would   
   >>>>>>>>>> most   
   >>>>>>>>>> likely get much brighter and burn out, so I'd have to adjust that,   
   >>>>>>>>>> but the   
   >>>>>>>>>> others which only flicker 8% would just get 4% brighter.   
   >>>>>>>   
   >>>>>>> you could use being 4 % brighter   
   >>>>>>   
   >>>>>> That would make my IQ 140.   
   >>>>>>   
   >>>>>> Was the above too difficult for you to discuss?   
   >>>>>   
   >>>>> I Q's are the lamest oldest forgotten tests of them all ,   
   >>>>   
   >>>> You're just jealous.   
   >>>>   
   >>>>> are you excited this is going to be how usenet is for you for the next   
   >>>>> 20 - 30 years   
   >>>>   
   >>>> Be more specific.   
   >>>   
   >>> no and start getting used to the idea that i don't do what you order   
   >>   
   >> No point in you telling me something if you won't back it up.   
   >   
   > say it to my face and we'll see about back up   
      
   I picture you as a geeky little wimp, and as such I am not afraid of you.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)