Re: Tv reception

From	Tony <nomail@nospam.com>
Newsgroups	aus.electronics, aus.computers
Subject	Re: Tv reception
Date	2017-02-09 06:12 +0800
Organization	A noiseless patient Spider
Message-ID	<o7g50g$v9d$1@dont-email.me> (permalink)
References	(7 earlier) <wH5mA.248894$dT1.27701@fx16.am4> <o7aul7$86n$1@dont-email.me> <RqpmA.247125$a22.222791@fx28.am4> <o7dock$fsf$1@dont-email.me> <P9KmA.757044$c41.136034@fx40.am4>

Cross-posted to 2 groups.

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On 09-Feb-17 3:18 AM, Benderthe.evilrobot wrote:
>
> "Tony" <nomail@nospam.com> wrote in message
> news:o7dock$fsf$1@dont-email.me...
>> On 08-Feb-17 3:42 AM, Benderthe.evilrobot wrote:
>>>
>>> "Tony" <nomail@nospam.com> wrote in message
>>> news:o7aul7$86n$1@dont-email.me...
>>>> On 07-Feb-17 5:15 AM, Benderthe.evilrobot wrote:
>>>>>
>>>>> "Rod Speed" <rod.speed.aaa@gmail.com> wrote in message
>>>>> news:efs442Fg7ciU1@mid.individual.net...
>>>>>>
>>>>>>
>>>>>> "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> wrote in
>>>>>> message news:eo4mA.23709$8K.5710@fx46.am4...
>>>>>>>
>>>>>>> "Rod Speed" <rod.speed.aaa@gmail.com> wrote in message
>>>>>>> news:efphvdFdimU1@mid.individual.net...
>>>>>>>>
>>>>>>>>
>>>>>>>> "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com>
>>>>>>>> wrote in
>>>>>>>> message news:sfMlA.195747$yv3.192638@fx30.am4...
>>>>>>>>>
>>>>>>>>> "F Murtz" <haggisz@hotmail.com> wrote in message
>>>>>>>>> news:5895e20f$0$55943$b1db1813$65575428@news.astraweb.com...
>>>>>>>>>> Lucifer Morningstar wrote:
>>>>>>>>>>> On Sat, 4 Feb 2017 23:49:55 +1100, F Murtz <haggisz@hotmail.com>
>>>>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>>> For months I have been having problems with tv reception TV not
>>>>>>>>>>>> working
>>>>>>>>>>>> on most channels for hours, I have been blaming 4g towers,
>>>>>>>>>>>> fixed
>>>>>>>>>>>> wireless towers etc that have just been put up etc.
>>>>>>>>>>>> I have just found the cause by accident, almost unbelievable.
>>>>>>>>>>>> TV does not work if the kitchen light is on.
>>>>>>>>>>>> The culprit is one of these, a 12" or so multiple led ceiling
>>>>>>>>>>>> LED
>>>>>>>>>>>> similar to this,
>>>>>>>>>>>>   http://imgur.com/a/dj5ha
>>>>>>>>>>>
>>>>>>>>>>> My electric fence was interfering with my TV reception.
>>>>>>>>>>>
>>>>>>>>>> If I had an electric fence that would be one of the first
>>>>>>>>>> suspects
>>>>>>>>>> but who would think turning a light on would cause it,
>>>>>>>>>
>>>>>>>>> Its been a possible problem with CFLs for years.
>>>>>>>>>
>>>>>>>>> Some of the LED replacement bulbs use a wattless dropper
>>>>>>>>> instead of
>>>>>>>>> SMPSU circuitry. You might be able to adapt it, but don't
>>>>>>>>> forget to
>>>>>>>>> include a surge limiting resistor - the current is very high
>>>>>>>>> around
>>>>>>>>> the zero crossing portion of the AC waveform.
>>>>>>>>
>>>>>>>> That's mad, the current will be very low around the zero
>>>>>>>> crossing of
>>>>>>>> the AC waveform.
>>>>>>>
>>>>>>> Three words - "rate of change".
>>>>>>
>>>>>> It has nothing to do with rate of change, the voltage by definition
>>>>>> is close to zero, so the current is in fact very low. Ohms law.
>>>>>
>>>>> Geez - and I thought I wasn't great at AC
>>>>> theory..........................
>>>>>
>>>>> A coupling capacitor (wattless dropper) blocks DC, the AC waveform is
>>>>> almost that at the peaks. The capacitor only passes a rate of change -
>>>>> that's at its greatest around the zero crossing points.
>>>>>
>>>>> Maybe you should lay off the booze (or whatever)........
>>>>
>>>> I have put such a circuit in a simulator, and except for the inrush
>>>> current I don't see anything like you said.
>>>> Try it yourself, like on: http://www.falstad.com/circuit/
>>>> Select 'File', 'import from text', and paste this text, a simple
>>>> example:
>>>>
>>>> $ 1 0.000005 3.452441195350251 45 5 43
>>>> s 688 96 752 96 0 0 false
>>>> v 752 368 752 96 0 1 50 330 0 0 0.5
>>>> d 480 352 480 240 1 0.805904783
>>>> d 576 112 576 208 1 0.805904783
>>>> w 688 96 576 96 0
>>>> w 576 96 576 112 0
>>>> w 480 96 576 96 0
>>>> w 480 352 480 368 0
>>>> d 416 144 416 96 1 0.805904783
>>>> d 416 272 416 352 1 0.805904783
>>>> w 480 96 416 96 0
>>>> w 416 352 416 368 0
>>>> w 432 368 480 368 0
>>>> 370 688 368 752 368 1 0
>>>> 162 480 224 480 160 1 2.1024259 1 0 0 0.01
>>>> 162 512 224 512 160 1 2.1024259 1 0 0 0.01
>>>> 162 544 224 544 160 1 2.1024259 1 0 0 0.01
>>>> w 480 144 480 160 0
>>>> w 480 160 512 160 0
>>>> w 512 160 544 160 0
>>>> w 544 224 512 224 0
>>>> w 512 224 480 224 0
>>>> w 432 144 416 144 0
>>>> c 560 368 624 368 0 5e-7 -9.1361757825205
>>>> w 688 368 624 368 0
>>>> w 560 368 480 368 0
>>>> w 416 144 416 160 0
>>>> w 416 160 416 272 0
>>>> w 432 368 416 368 0
>>>> w 432 144 480 144 0
>>>> w 480 240 480 224 0
>>>> r 560 320 624 320 0 220000
>>>> w 560 320 560 368 0
>>>> w 624 320 624 368 0
>>>> w 576 208 576 224 0
>>>> w 480 240 576 240 0
>>>> w 576 240 576 224 0
>>>> o 1 64 0 2083 640 0.1 0 -1 0
>>>> o 30 64 0 2083 640 0.1 1 -1 0
>>>>
>>>> You have to reset the simulation and start again do get the current
>>>> range to normal after the inrush.
>>>> AFAIK The only important thing to remember is to use at least an X3
>>>> rated capacitor and a discharge resistor across the cap, so yo don't
>>>> get zapped when touching the open pins.
>>>
>>> If you have to reset it after the inrush - that's probably why you're
>>> not seeing the cycle by cycle current peaks around the point of maximum
>>> rate of change.
>>
>> No, you have to reset it because the range of the current display has
>> expanded so much, by the inrush, that you don't see the normal current
>> curve.
>
> "normal current curve"? - its only the sinusoidal drive that takes the
> edge off the capacitor current that peaks around the zero crossing point.
>
> You could switch the circuit on *ANYWHERE* on the cycle - it could be at
> the peak and cause a big current pulse, or at zero where it starts at
> zero and rises pretty much the same as continuous operation.
>
> The AC current in a theoretically ideal capacitor leads voltage by 90
> degrees - its not some great mystery from an alternate universe with
> different laws of physics.

It's you that need to get real. The current does not "get very high' 
around the zero crossing. It just reaches its maximum there because of 
the phase shift of the capacitor. The resistor you were talking about is 
only there to protect the circuit from melt down in case the capacitor 
shorts out. Full stop. Unless you have a non-linear load that's just the 
end of the discussion.

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Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-04 23:49 +1100
  Re: Tv reception Lucifer Morningstar <Barry@saymyname.com> - 2017-02-05 00:08 +1100
    Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-05 01:15 +1100
      Re: Tv reception "Max" <max@val.morgan> - 2017-02-05 07:34 +1100
        Re: Tv reception "~misfit~" <shaun.at.pukekohe@gmail.com> - 2017-02-05 14:09 +1300
        Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-05 13:45 +1100
      Re: Tv reception Lucifer Morningstar <Barry@saymyname.com> - 2017-02-05 08:50 +1100
        Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-05 20:54 +0000
      Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-05 20:51 +0000
        Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-06 07:58 +1100
          Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-06 19:46 +0000
            Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-07 07:20 +1100
              Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-06 21:15 +0000
                Re: Tv reception Tony <nomail@nospam.com> - 2017-02-07 06:53 +0800
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-07 19:42 +0000
                Re: Tv reception Tony <nomail@nospam.com> - 2017-02-08 08:24 +0800
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-08 19:18 +0000
                Re: Tv reception Tony <nomail@nospam.com> - 2017-02-09 06:12 +0800
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-09 21:51 +0000
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-10 11:41 +1100
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-10 19:49 +0000
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-11 07:58 +1100
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-10 21:19 +0000
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-11 12:52 +1100
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-11 18:52 +0000
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-12 08:28 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-11 09:18 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-11 09:17 +1100
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-11 18:53 +0000
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-07 10:23 +1100
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-07 19:44 +0000
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-08 13:51 +1100
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-08 19:20 +0000
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-09 06:43 +1100
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-08 21:37 +0000
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-09 08:53 +1100
                Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-08 22:05 +0000
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-09 10:55 +1100
        Re: Tv reception Tony <nomail@nospam.com> - 2017-02-06 11:26 +0800
    Re: Tv reception "Blue Peeler" <woof@barque.org> - 2017-02-04 21:45 +0000
      Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-05 20:56 +0000
        Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-06 10:06 +1100
          Re: Tv reception Jasen Betts <jasen@xnet.co.nz> - 2017-02-06 02:36 +0000
            Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-06 22:59 +1100
            Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-06 19:50 +0000
  Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-05 06:11 +1100
    Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-05 12:57 +1100
      Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-05 13:49 +1100
        Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-05 14:24 +1100
  Re: Tv reception "Blue Peeler" <woof@barque.org> - 2017-02-04 21:44 +0000
  Re: Tv reception Clifford Heath <no.spam@please.net> - 2017-02-05 08:48 +1100
  Re: Tv reception not@telling.you.invalid (Computer Nerd Kev) - 2017-02-04 22:21 +0000
    Re: Tv reception Clifford Heath <no.spam@please.net> - 2017-02-05 09:44 +1100
      Re: Tv reception not@telling.you.invalid (Computer Nerd Kev) - 2017-02-05 00:00 +0000
        Re: Tv reception noel <deletethis@invalid.lan> - 2017-02-05 11:49 +1000
          Re: Tv reception Computer Nerd Kev <not@telling.you.invalid> - 2017-02-05 05:31 +0000
      Re: Tv reception noel <deletethis@invalid.lan> - 2017-02-05 11:48 +1000
        Re: Tv reception Computer Nerd Kev <not@telling.you.invalid> - 2017-02-05 05:25 +0000
          Re: Tv reception "~misfit~" <shaun.at.pukekohe@gmail.com> - 2017-02-06 13:30 +1300
            Re: Tv reception not@telling.you.invalid (Computer Nerd Kev) - 2017-02-06 21:19 +0000
            Re: Tv reception Jasen Betts <jasen@xnet.co.nz> - 2017-02-07 03:06 +0000
              Re: Tv reception "~misfit~" <shaun.at.pukekohe@gmail.com> - 2017-02-07 20:50 +1300
    Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-05 13:51 +1100
      Re: Tv reception Computer Nerd Kev <not@telling.you.invalid> - 2017-02-05 05:34 +0000
      Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-05 17:10 +1100
        Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-05 18:25 +1100
          Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-05 19:09 +1100
            Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-05 19:58 +1100
              Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-05 23:12 +1100
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-06 03:52 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-06 12:18 +1100
            Re: Tv reception felix <me@nothere.invalid> - 2017-02-06 00:04 +1100
              Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-06 07:54 +1100
              Re: Tv reception "~misfit~" <shaun.at.pukekohe@gmail.com> - 2017-02-06 13:32 +1300
                Re: Tv reception Xeno <xenolith@optusnet.com.au> - 2017-02-06 11:44 +1100
  Re: Tv reception "Benderthe.evilrobot" <Benderthe.evilrobot@virginmedia.com> - 2017-02-05 20:43 +0000
    Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-06 10:03 +1100
      Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-07 17:36 +1100
        Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-07 17:56 +1100
          Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-07 18:38 +1100
            Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-07 19:37 +1100
            Re: Tv reception Xeno <xenolith@optusnet.com.au> - 2017-02-08 00:07 +1100
        Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-08 08:54 +1100
          Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-08 08:55 +1100
            Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-10 22:42 +1100
              Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-11 09:21 +1100
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-11 12:58 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-11 15:42 +1100
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-11 16:45 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-11 17:26 +1100
                Re: Tv reception Phil Allison <pallison49@gmail.com> - 2017-02-10 21:49 -0800
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-11 17:22 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-11 17:37 +1100
                Re: Tv reception Phil Allison <pallison49@gmail.com> - 2017-02-10 23:18 -0800
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-12 03:26 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-12 09:54 +1100
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-12 12:57 +1100
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-12 16:16 +1100
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-12 16:24 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-12 17:39 +1100
                Re: Tv reception "~misfit~" <shaun.at.pukekohe@gmail.com> - 2017-02-13 00:49 +1300
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-13 01:59 +1100
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-13 07:22 +1100
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-13 13:31 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-13 14:58 +1100
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-13 15:29 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-13 17:30 +1100
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-14 20:33 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-14 21:25 +1100
                Re: Tv reception "Rod Speed" <rod.speed.aaa@gmail.com> - 2017-02-15 05:44 +1100
                Re: Tv reception F Murtz <haggisz@hotmail.com> - 2017-02-15 12:26 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-15 16:26 +1100
                Re: Tv reception Petzl <petzlx@gmail.com> - 2017-02-13 13:04 +1100

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