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Groups > sci.electronics.design > #742925 > unrolled thread
| Started by | "Don" <g@crcomp.net> |
|---|---|
| First post | 2026-04-12 05:34 +0000 |
| Last post | 2026-04-25 15:47 +1000 |
| Articles | 20 on this page of 102 — 10 participants |
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CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-12 05:34 +0000
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-12 10:45 +0100
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-12 10:48 +0100
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-12 10:50 +0100
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-12 12:03 +0100
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-12 04:44 -0700
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-12 04:19 -0700
Re: CoB LED filament analysis piglet <erichpwagner@hotmail.com> - 2026-04-13 07:40 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-13 01:46 -0700
Re: CoB LED filament analysis piglet <erichpwagner@hotmail.com> - 2026-04-13 11:40 +0000
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-13 14:31 +0100
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-13 06:59 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-14 12:25 +0000
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-14 14:04 +0100
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-14 08:21 -0700
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-15 02:48 +1000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-14 11:14 -0700
Re: CoB LED filament analysis piglet <erichpwagner@hotmail.com> - 2026-04-14 19:25 +0100
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-14 19:43 +0100
Re: CoB LED filament analysis piglet <erichpwagner@hotmail.com> - 2026-04-14 20:19 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-14 12:54 -0700
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-14 19:42 +0100
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-14 12:57 -0700
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-14 13:02 -0700
Re: CoB LED filament analysis piglet <erichpwagner@hotmail.com> - 2026-04-14 21:29 +0100
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-14 19:10 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-15 11:36 +0000
Re: CoB LED filament analysis piglet <erichpwagner@hotmail.com> - 2026-04-15 12:35 +0000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-21 14:39 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-21 08:41 -0700
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-21 08:54 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-21 16:55 +0000
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-22 03:54 +1000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-21 21:05 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-21 17:03 -0700
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-21 12:26 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-22 01:44 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-21 19:16 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-24 13:37 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-24 07:55 -0700
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-24 08:04 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-24 16:43 +0000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-24 20:15 +0000
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-26 03:45 +1000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-25 11:14 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-25 22:56 +0000
Re: CoB LED filament analysis ehsjr <ehsjr@verizon.net> - 2026-04-25 21:33 -0400
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-26 02:18 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-25 20:08 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-26 04:44 +0000
Re: CoB LED filament analysis Arie de Muijnck <noreply@ademu.nl> - 2026-04-26 13:03 +0200
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-26 11:35 +0000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-26 11:43 +0000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-26 16:44 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-26 10:17 -0700
Re: CoB LED filament analysis Arie de Muijnck <noreply@ademu.nl> - 2026-04-26 19:58 +0200
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-26 19:22 +0000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-05-19 03:30 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-05-19 08:26 -0700
Re: CoB LED filament analysis Arie de Muijnck <noreply@ademu.nl> - 2026-05-19 18:23 +0200
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-05-19 09:52 -0700
Re: CoB LED filament analysis Jeroen Belleman <jeroen@nospam.please> - 2026-04-26 20:30 +0200
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-26 18:24 +0100
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-26 17:52 +0000
Re: CoB LED filament analysis piglet <erichpwagner@hotmail.com> - 2026-04-26 19:17 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-25 20:10 -0700
Re: CoB LED filament analysis Jeroen Belleman <jeroen@nospam.please> - 2026-04-24 22:23 +0200
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-24 15:42 -0700
Re: CoB LED filament analysis Jeroen Belleman <jeroen@nospam.please> - 2026-04-25 10:53 +0200
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-26 12:05 -0700
Re: CoB LED filament analysis piglet <erichpwagner@hotmail.com> - 2026-04-26 19:20 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-27 12:49 -0700
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-27 17:04 +1000
Re: CoB LED filament analysis Jeroen Belleman <jeroen@nospam.please> - 2026-04-27 10:59 +0200
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-27 08:11 -0700
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-28 01:51 +1000
Re: CoB LED filament analysis Jeroen Belleman <jeroen@nospam.please> - 2026-04-27 21:40 +0200
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-22 16:36 +0100
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-22 17:10 +0000
Re: CoB LED filament analysis JM <sunaecoNoChoppedPork@gmail.com> - 2026-04-22 18:17 +0100
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-22 17:31 +0000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-22 18:14 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-22 11:23 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-22 18:43 +0000
Re: CoB LED filament analysis Jeroen Belleman <jeroen@nospam.please> - 2026-04-22 23:50 +0200
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-22 11:24 -0700
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-23 17:22 +1000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-23 07:58 -0700
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-23 17:15 +0000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-23 21:26 +0000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-24 02:53 +0000
Re: CoB LED filament analysis John R Walliker <jrwalliker@gmail.com> - 2026-04-24 18:19 +0100
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-24 10:39 -0700
Re: CoB LED filament analysis John R Walliker <jrwalliker@gmail.com> - 2026-04-24 21:39 +0100
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-24 15:19 -0700
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-25 15:23 +1000
Re: CoB LED filament analysis "Don" <g@crcomp.net> - 2026-04-24 17:45 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-24 11:12 -0700
Re: CoB LED filament analysis Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2026-04-24 18:30 +0000
Re: CoB LED filament analysis john larkin <jl@glen--canyon.com> - 2026-04-24 11:42 -0700
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-25 15:49 +1000
Re: CoB LED filament analysis Bill Sloman <bill.sloman@ieee.org> - 2026-04-25 15:47 +1000
Page 5 of 6 — ← Prev page 1 2 3 4 [5] 6 Next page →
| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-22 17:31 +0000 |
| Message-ID | <20260422b@crcomp.net> |
| In reply to | #743244 |
JM wrote:
> Don wrote:
>
>>What does a forking fantasy about faffing have to do with your bright
>>idea to use a series resistor to create a current curve? 1, 10, 100,
>>10K, 100K, 1M series resistors all show slightly attenuated 320 VAC.
>>What do you think about that?
>
> So you think you see 320V ac across a 1 ohm resistor.
The question is, what do you think you see when you look at:
<https://crcomp.net/ledfilament/curveresistor.png>
Danke,
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/wd7q vos |
[toc] | [prev] | [next] | [standalone]
| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-22 18:14 +0000 |
| Message-ID | <20260422d@crcomp.net> |
| In reply to | #743248 |
Don wrote:
> JM wrote:
>> Don wrote:
>>
>>>What does a forking fantasy about faffing have to do with your bright
>>>idea to use a series resistor to create a current curve? 1, 10, 100,
>>>10K, 100K, 1M series resistors all show slightly attenuated 320 VAC.
>>>What do you think about that?
>>
>> So you think you see 320V ac across a 1 ohm resistor.
>
> The question is, what do you think you see when you look at:
>
> <https://crcomp.net/ledfilament/curveresistor.png>
Forget about all the above stupid questions and be honest. What did
you expect a current curve to reveal about a device that draws mA
from 320 ACVp-p?
It takes a fool to follow foolish advice. Fool me once, shame on you.
Fool me twice, shame on me.
Danke,
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/wd7q vos |
[toc] | [prev] | [next] | [standalone]
| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-22 11:23 -0700 |
| Message-ID | <uf4iuktguqrcd3vp5euet7k312g84tda00@4ax.com> |
| In reply to | #743249 |
On Wed, 22 Apr 2026 18:14:02 -0000 (UTC), "Don" <g@crcomp.net> wrote: >Don wrote: >> JM wrote: >>> Don wrote: >>> >>>>What does a forking fantasy about faffing have to do with your bright >>>>idea to use a series resistor to create a current curve? 1, 10, 100, >>>>10K, 100K, 1M series resistors all show slightly attenuated 320 VAC. >>>>What do you think about that? >>> >>> So you think you see 320V ac across a 1 ohm resistor. >> >> The question is, what do you think you see when you look at: >> >> <https://crcomp.net/ledfilament/curveresistor.png> > >Forget about all the above stupid questions and be honest. What did >you expect a current curve to reveal about a device that draws mA >from 320 ACVp-p? What's inside? John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
[toc] | [prev] | [next] | [standalone]
| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-22 18:43 +0000 |
| Message-ID | <20260422e@crcomp.net> |
| In reply to | #743250 |
john larkin wrote:
Don wrote:
<usenet stupidity snipped>
>>What did
>>you expect a current curve to reveal about a device that draws mA
>>from 320 ACVp-p?
>
> What's inside?
Fair enough. Given a rock solid resitive load with a phase shift of zero,
then there's something wrong with the phase shown by the current probe.
It's my hunch that the waveform itself shows something useful.
I'll repeat the experiment with a 100 ohm current sense series resister
in case something was overlooked the first time.
Danke,
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/wd7q vos |
[toc] | [prev] | [next] | [standalone]
| From | Jeroen Belleman <jeroen@nospam.please> |
|---|---|
| Date | 2026-04-22 23:50 +0200 |
| Message-ID | <10sbfre$2i4h6$1@dont-email.me> |
| In reply to | #743252 |
On 4/22/26 20:43, Don wrote: > john larkin wrote: > Don wrote: > > <usenet stupidity snipped> > >>> What did >>> you expect a current curve to reveal about a device that draws mA >> >from 320 ACVp-p? >> >> What's inside? > > Fair enough. Given a rock solid resitive load with a phase shift of zero, > then there's something wrong with the phase shown by the current probe. > It's my hunch that the waveform itself shows something useful. > > I'll repeat the experiment with a 100 ohm current sense series resister > in case something was overlooked the first time. > > Danke, > > -- > 73, Don, WD7Q veritas _|_ > liberabit | > https://www.qsl.net/wd7q vos | > There's something wrong with your measurements. I'd like to see a schematic of your setup. And what's the load impedance on your current probe? Is its frequency response even good down to 50 Hz? The voltage across a 100 Ohm current sense resistor passing a mA should be 100 mV, simple Ohm's law. If you see 320V, there's something wrong. Jeroen Belleman
[toc] | [prev] | [next] | [standalone]
| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-22 11:24 -0700 |
| Message-ID | <sh4iukhg0v5cicej6ja18pks64lt3634gu@4ax.com> |
| In reply to | #743244 |
On Wed, 22 Apr 2026 18:17:41 +0100, JM <sunaecoNoChoppedPork@gmail.com> wrote: >On Wed, 22 Apr 2026 17:10:51 -0000 (UTC), "Don" <g@crcomp.net> wrote: > >>What does a forking fantasy about faffing have to do with your bright >>idea to use a series resistor to create a current curve? 1, 10, 100, >>10K, 100K, 1M series resistors all show slightly attenuated 320 VAC. >>What do you think about that? > >So you think you see 320V ac across a 1 ohm resistor. > >Think about it. Very bright flash? John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
[toc] | [prev] | [next] | [standalone]
| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-04-23 17:22 +1000 |
| Message-ID | <10schc3$2qlkn$7@dont-email.me> |
| In reply to | #743251 |
On 23/04/2026 4:24 am, john larkin wrote: > On Wed, 22 Apr 2026 18:17:41 +0100, JM > <sunaecoNoChoppedPork@gmail.com> wrote: > >> On Wed, 22 Apr 2026 17:10:51 -0000 (UTC), "Don" <g@crcomp.net> wrote: >> >>> What does a forking fantasy about faffing have to do with your bright >>> idea to use a series resistor to create a current curve? 1, 10, 100, >>> 10K, 100K, 1M series resistors all show slightly attenuated 320 VAC. >>> What do you think about that? >> >> So you think you see 320V ac across a 1 ohm resistor. >> >> Think about it. > > Very bright flash? There's not a lot of intellectual brilliance on show in this thread. -- Bill Sloman, Sydney
[toc] | [prev] | [next] | [standalone]
| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-23 07:58 -0700 |
| Message-ID | <b8ckukt23vpd4eb3sci6cl93vq9mk9d7cr@4ax.com> |
| In reply to | #743265 |
On Thu, 23 Apr 2026 17:22:33 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 23/04/2026 4:24 am, john larkin wrote: >> On Wed, 22 Apr 2026 18:17:41 +0100, JM >> <sunaecoNoChoppedPork@gmail.com> wrote: >> >>> On Wed, 22 Apr 2026 17:10:51 -0000 (UTC), "Don" <g@crcomp.net> wrote: >>> >>>> What does a forking fantasy about faffing have to do with your bright >>>> idea to use a series resistor to create a current curve? 1, 10, 100, >>>> 10K, 100K, 1M series resistors all show slightly attenuated 320 VAC. >>>> What do you think about that? >>> >>> So you think you see 320V ac across a 1 ohm resistor. >>> >>> Think about it. >> >> Very bright flash? > >There's not a lot of intellectual brilliance on show in this thread. There are a lot of people who are interested in electronics - the curiosity about the COB LED is admirable - but don't have good quantitative instincts for it. I went to a hardware pitch meeting last night. There were three VCs with money, and five startups making pitches for same. We, the audience, were there to applaud or something. The beer and pizza were free. What impressed me was that the pitched ideas were so goofy, but more impressive was that they were all electronic intensive and the people obviously weren't very good with electronics. Two things are crazy fads here now: AI and robotics. The robotics that I'm seeing are clumsy toys with about nine times more klugy electronics and wiring than they need. Most would do fine with a DIN rail PLC. Strange times. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
[toc] | [prev] | [next] | [standalone]
| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-23 17:15 +0000 |
| Message-ID | <20260423a@crcomp.net> |
| In reply to | #743267 |
john larkin wrote:
> Bill Sloman wrote:
>> john larkin wrote:
>>> JM wrote:
>>>> Don wrote:
>>>>
>>>>> What does a forking fantasy about faffing have to do with your bright
>>>>> idea to use a series resistor to create a current curve? 1, 10, 100,
>>>>> 10K, 100K, 1M series resistors all show slightly attenuated 320 VAC.
>>>>> What do you think about that?
>>>>
>>>> So you think you see 320V ac across a 1 ohm resistor.
>>>>
>>>> Think about it.
>>>
>>> Very bright flash?
>>
>>There's not a lot of intellectual brilliance on show in this thread.
>
> There are a lot of people who are interested in electronics - the
> curiosity about the COB LED is admirable - but don't have good
> quantitative instincts for it.
>
> I went to a hardware pitch meeting last night. There were three VCs
> with money, and five startups making pitches for same. We, the
> audience, were there to applaud or something. The beer and pizza were
> free.
>
> What impressed me was that the pitched ideas were so goofy, but more
> impressive was that they were all electronic intensive and the people
> obviously weren't very good with electronics.
>
> Two things are crazy fads here now: AI and robotics. The robotics that
> I'm seeing are clumsy toys with about nine times more klugy
> electronics and wiring than they need. Most would do fine with a DIN
> rail PLC.
>
> Strange times.
This thread turned too treacherous. It's time for a brain teaser to
get things back on track. Put on your quantitative instincts hat and
take a good long look at all of the images shown at:
<https://crcomp.net/ledfilament/index.php>
Now put on your thinking cap. There's something glaringly wrong (so to
speak) with the experiment. It may explain the phase difference
discrepancy. Stay tuned.
Danke,
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/wd7q vos |
[toc] | [prev] | [next] | [standalone]
| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-23 21:26 +0000 |
| Message-ID | <20260423b@crcomp.net> |
| In reply to | #743273 |
Don wrote:
<snip>
> It's time for a brain teaser to
> get things back on track. Put on your quantitative instincts hat and
> take a good long look at all of the images shown at:
>
> <https://crcomp.net/ledfilament/index.php>
>
> Now put on your thinking cap. There's something glaringly wrong (so to
> speak) with the experiment. It may explain the phase difference
> discrepancy. Stay tuned.
Alright you guys, this thread's fun again! There's yet another
intuitively obvious source of error for those with quantitative
instinctive eyes to see. And it has nothing whatsoever to do with my
320 VACp-p typo. Hint: imagine how my empirical current curves could
be correct.
Danke,
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/wd7q vos |
[toc] | [prev] | [next] | [standalone]
| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-24 02:53 +0000 |
| Message-ID | <20260423c@crcomp.net> |
| In reply to | #743285 |
Don <g@crcomp.net> wrote:
> Don wrote:
>
> <snip>
>
>> It's time for a brain teaser to
>> get things back on track. Put on your quantitative instincts hat and
>> take a good long look at all of the images shown at:
>>
>> <https://crcomp.net/ledfilament/index.php>
>>
>> Now put on your thinking cap. There's something glaringly wrong (so to
>> speak) with the experiment. It may explain the phase difference
>> discrepancy. Stay tuned.
>
> Alright you guys, this thread's fun again! There's yet another
> intuitively obvious source of error for those with quantitative
> instinctive eyes to see. And it has nothing whatsoever to do with my
> 320 VACp-p typo. Hint: imagine how my empirical current curves could
> be correct.
Nailed it! The expected curves now appear. Yet, my original current
curves are flawless. Filament faffing finally pays off. Uninhibited
brainstorming, no matter how insane it is in the interim, imparts
insight. Next clue: Bob Pease.
Danke,
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/wd7q vos |
[toc] | [prev] | [next] | [standalone]
| From | John R Walliker <jrwalliker@gmail.com> |
|---|---|
| Date | 2026-04-24 18:19 +0100 |
| Message-ID | <10sg8na$3jsof$4@dont-email.me> |
| In reply to | #743293 |
On 24/04/2026 03:53, Don wrote: > Don <g@crcomp.net> wrote: >> Don wrote: >> >> <snip> >> >>> It's time for a brain teaser to >>> get things back on track. Put on your quantitative instincts hat and >>> take a good long look at all of the images shown at: >>> >>> <https://crcomp.net/ledfilament/index.php> >>> >>> Now put on your thinking cap. There's something glaringly wrong (so to >>> speak) with the experiment. It may explain the phase difference >>> discrepancy. Stay tuned. >> >> Alright you guys, this thread's fun again! There's yet another >> intuitively obvious source of error for those with quantitative >> instinctive eyes to see. And it has nothing whatsoever to do with my >> 320 VACp-p typo. Hint: imagine how my empirical current curves could >> be correct. The LED string does not begin to conduct until the peak voltage has been reached. Then the current increases abruptly and the voltage collapses due to a relatively high source impedance. The string continues to conduct even as the voltage is collapsing. The voltage collapse is not immediate because there is a significant capacitance across the LED string after the source resistance (which may be the current sense resistor). John > > Nailed it! The expected curves now appear. Yet, my original current > curves are flawless. Filament faffing finally pays off. Uninhibited > brainstorming, no matter how insane it is in the interim, imparts > insight. Next clue: Bob Pease. > > Danke, > > -- > 73, Don, WD7Q veritas _|_ > liberabit | > https://www.qsl.net/wd7q vos | >
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-24 10:39 -0700 |
| Message-ID | <clanukdpoefq7tup8n7arejj6va18biab5@4ax.com> |
| In reply to | #743317 |
On Fri, 24 Apr 2026 18:19:38 +0100, John R Walliker <jrwalliker@gmail.com> wrote: >On 24/04/2026 03:53, Don wrote: >> Don <g@crcomp.net> wrote: >>> Don wrote: >>> >>> <snip> >>> >>>> It's time for a brain teaser to >>>> get things back on track. Put on your quantitative instincts hat and >>>> take a good long look at all of the images shown at: >>>> >>>> <https://crcomp.net/ledfilament/index.php> >>>> >>>> Now put on your thinking cap. There's something glaringly wrong (so to >>>> speak) with the experiment. It may explain the phase difference >>>> discrepancy. Stay tuned. >>> >>> Alright you guys, this thread's fun again! There's yet another >>> intuitively obvious source of error for those with quantitative >>> instinctive eyes to see. And it has nothing whatsoever to do with my >>> 320 VACp-p typo. Hint: imagine how my empirical current curves could >>> be correct. > >The LED string does not begin to conduct until the peak voltage has >been reached. Then the current increases abruptly and the voltage >collapses due to a relatively high source impedance. The string >continues to conduct even as the voltage is collapsing. The >voltage collapse is not immediate because there is a significant >capacitance across the LED string after the source resistance >(which may be the current sense resistor). > >John Umm, no. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | John R Walliker <jrwalliker@gmail.com> |
|---|---|
| Date | 2026-04-24 21:39 +0100 |
| Message-ID | <10sgkeb$3jsof$6@dont-email.me> |
| In reply to | #743321 |
On 24/04/2026 18:39, john larkin wrote: > On Fri, 24 Apr 2026 18:19:38 +0100, John R Walliker > <jrwalliker@gmail.com> wrote: > >> On 24/04/2026 03:53, Don wrote: >>> Don <g@crcomp.net> wrote: >>>> Don wrote: >>>> >>>> <snip> >>>> >>>>> It's time for a brain teaser to >>>>> get things back on track. Put on your quantitative instincts hat and >>>>> take a good long look at all of the images shown at: >>>>> >>>>> <https://crcomp.net/ledfilament/index.php> >>>>> >>>>> Now put on your thinking cap. There's something glaringly wrong (so to >>>>> speak) with the experiment. It may explain the phase difference >>>>> discrepancy. Stay tuned. >>>> >>>> Alright you guys, this thread's fun again! There's yet another >>>> intuitively obvious source of error for those with quantitative >>>> instinctive eyes to see. And it has nothing whatsoever to do with my >>>> 320 VACp-p typo. Hint: imagine how my empirical current curves could >>>> be correct. >> >> The LED string does not begin to conduct until the peak voltage has >> been reached. Then the current increases abruptly and the voltage >> collapses due to a relatively high source impedance. The string >> continues to conduct even as the voltage is collapsing. The >> voltage collapse is not immediate because there is a significant >> capacitance across the LED string after the source resistance >> (which may be the current sense resistor). >> >> John > > Umm, no. OK then. What is wrong with my interpretation? There is a sudden drop in the voltage waveform which implies a sudden increase in the current drawn. The current waveform confirms this. The slope in the voltage waveform suggests a capacitive component. There must be some hysteresis, which is the most puzzling element. > John Larkin > Highland Tech Glen Canyon Design Center > Lunatic Fringe Electronics
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-24 15:19 -0700 |
| Message-ID | <0ponuk58f6uj0iiiutb9qv42vbnkabdf6c@4ax.com> |
| In reply to | #743333 |
On Fri, 24 Apr 2026 21:39:39 +0100, John R Walliker <jrwalliker@gmail.com> wrote: >On 24/04/2026 18:39, john larkin wrote: >> On Fri, 24 Apr 2026 18:19:38 +0100, John R Walliker >> <jrwalliker@gmail.com> wrote: >> >>> On 24/04/2026 03:53, Don wrote: >>>> Don <g@crcomp.net> wrote: >>>>> Don wrote: >>>>> >>>>> <snip> >>>>> >>>>>> It's time for a brain teaser to >>>>>> get things back on track. Put on your quantitative instincts hat and >>>>>> take a good long look at all of the images shown at: >>>>>> >>>>>> <https://crcomp.net/ledfilament/index.php> >>>>>> >>>>>> Now put on your thinking cap. There's something glaringly wrong (so to >>>>>> speak) with the experiment. It may explain the phase difference >>>>>> discrepancy. Stay tuned. >>>>> >>>>> Alright you guys, this thread's fun again! There's yet another >>>>> intuitively obvious source of error for those with quantitative >>>>> instinctive eyes to see. And it has nothing whatsoever to do with my >>>>> 320 VACp-p typo. Hint: imagine how my empirical current curves could >>>>> be correct. >>> >>> The LED string does not begin to conduct until the peak voltage has >>> been reached. Then the current increases abruptly and the voltage >>> collapses due to a relatively high source impedance. The string >>> continues to conduct even as the voltage is collapsing. The >>> voltage collapse is not immediate because there is a significant >>> capacitance across the LED string after the source resistance >>> (which may be the current sense resistor). >>> >>> John >> >> Umm, no. > >OK then. What is wrong with my interpretation? >There is a sudden drop in the voltage waveform >which implies a sudden increase in the current drawn. >The current waveform confirms this. The slope in the >voltage waveform suggests a capacitive component. >There must be some hysteresis, which is the most >puzzling element. > > > >> John Larkin >> Highland Tech Glen Canyon Design Center >> Lunatic Fringe Electronics With 60 Hz excitation, there will be no time lags. Nothing will be sudden. Instantaneous current will be about I = (Vline-Vleds) / R where R is the sum of the two end resistances. No time factor, no hysteresis. This needs a proper measurement. DC with a DVM would be best, since the AC scope measurements aren't working well. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-04-25 15:23 +1000 |
| Message-ID | <10shj5p$j3f6$3@dont-email.me> |
| In reply to | #743333 |
On 25/04/2026 6:39 am, John R Walliker wrote: > On 24/04/2026 18:39, john larkin wrote: >> On Fri, 24 Apr 2026 18:19:38 +0100, John R Walliker >> <jrwalliker@gmail.com> wrote: >> >>> On 24/04/2026 03:53, Don wrote: >>>> Don <g@crcomp.net> wrote: >>>>> Don wrote: >>>>> >>>>> <snip> >>>>> >>>>>> It's time for a brain teaser to >>>>>> get things back on track. Put on your quantitative instincts hat and >>>>>> take a good long look at all of the images shown at: >>>>>> >>>>>> <https://crcomp.net/ledfilament/index.php> >>>>>> >>>>>> Now put on your thinking cap. There's something glaringly wrong >>>>>> (so to >>>>>> speak) with the experiment. It may explain the phase difference >>>>>> discrepancy. Stay tuned. >>>>> >>>>> Alright you guys, this thread's fun again! There's yet another >>>>> intuitively obvious source of error for those with quantitative >>>>> instinctive eyes to see. And it has nothing whatsoever to do with my >>>>> 320 VACp-p typo. Hint: imagine how my empirical current curves could >>>>> be correct. >>> >>> The LED string does not begin to conduct until the peak voltage has >>> been reached. Then the current increases abruptly and the voltage >>> collapses due to a relatively high source impedance. The string >>> continues to conduct even as the voltage is collapsing. The >>> voltage collapse is not immediate because there is a significant >>> capacitance across the LED string after the source resistance >>> (which may be the current sense resistor). >>> >>> John >> >> Umm, no. > > OK then. What is wrong with my interpretation? > There is a sudden drop in the voltage waveform > which implies a sudden increase in the current drawn. > The current waveform confirms this. The slope in the > voltage waveform suggests a capacitive component. > There must be some hysteresis, which is the most > puzzling element. The current flow through an LED is a non-linear - exponential - function of the voltage across it. Essentially no current flows until you get close to about 3V across each LED. The series resistance then kicks in and holds the voltage across the LEDs to a bit over 3V per device. There's no capacitative component. As soon as the voltage across the string drops below about 3V per LED the LEDs stop conducting. Spice it. -- Bill Sloman, Sydney
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| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-24 17:45 +0000 |
| Message-ID | <20260424c@crcomp.net> |
| In reply to | #743317 |
John R Walliker <jrwalliker@gmail.com> wrote:
> On 24/04/2026 03:53, Don wrote:
>> Don <g@crcomp.net> wrote:
>>> Don wrote:
>>>
>>> <snip>
>>>
>>>> It's time for a brain teaser to
>>>> get things back on track. Put on your quantitative instincts hat and
>>>> take a good long look at all of the images shown at:
>>>>
>>>> <https://crcomp.net/ledfilament/index.php>
>>>>
>>>> Now put on your thinking cap. There's something glaringly wrong (so to
>>>> speak) with the experiment. It may explain the phase difference
>>>> discrepancy. Stay tuned.
>>>
>>> Alright you guys, this thread's fun again! There's yet another
>>> intuitively obvious source of error for those with quantitative
>>> instinctive eyes to see. And it has nothing whatsoever to do with my
>>> 320 VACp-p typo. Hint: imagine how my empirical current curves could
>>> be correct.
>
> The LED string does not begin to conduct until the peak voltage has
> been reached. Then the current increases abruptly and the voltage
> collapses due to a relatively high source impedance. The string
> continues to conduct even as the voltage is collapsing. The
> voltage collapse is not immediate because there is a significant
> capacitance across the LED string after the source resistance
> (which may be the current sense resistor).
>>
>> Nailed it! The expected curves now appear. Yet, my original current
>> curves are flawless. Filament faffing finally pays off. Uninhibited
>> brainstorming, no matter how insane it is in the interim, imparts
>> insight. Next clue: Bob Pease.
Larkin's correct about one thing. The filament's intrinsic capacitance
does not play a role in the observed phase shift.
When the last paragraph says "expected curves" it means current
curves with zero phase shift relative to voltage. The voltage and current
relationship is totally resistive, as expected.
While perusing TROUBLESHOOTING ANALOG CIRCUITS by Bob Pease for my next
hint, it occured to me how Larkin is the anti-Pease. And it goes a long
way in explaining Larkin's frequent battles with the late, great Jim
Thompson.
Danke,
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/wd7q vos |
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-24 11:12 -0700 |
| Message-ID | <l7cnuk1jc9gnta0er3lmdlqaqlnu65cr42@4ax.com> |
| In reply to | #743323 |
On Fri, 24 Apr 2026 17:45:22 -0000 (UTC), "Don" <g@crcomp.net> wrote: >John R Walliker <jrwalliker@gmail.com> wrote: >> On 24/04/2026 03:53, Don wrote: >>> Don <g@crcomp.net> wrote: >>>> Don wrote: >>>> >>>> <snip> >>>> >>>>> It's time for a brain teaser to >>>>> get things back on track. Put on your quantitative instincts hat and >>>>> take a good long look at all of the images shown at: >>>>> >>>>> <https://crcomp.net/ledfilament/index.php> >>>>> >>>>> Now put on your thinking cap. There's something glaringly wrong (so to >>>>> speak) with the experiment. It may explain the phase difference >>>>> discrepancy. Stay tuned. >>>> >>>> Alright you guys, this thread's fun again! There's yet another >>>> intuitively obvious source of error for those with quantitative >>>> instinctive eyes to see. And it has nothing whatsoever to do with my >>>> 320 VACp-p typo. Hint: imagine how my empirical current curves could >>>> be correct. >> >> The LED string does not begin to conduct until the peak voltage has >> been reached. Then the current increases abruptly and the voltage >> collapses due to a relatively high source impedance. The string >> continues to conduct even as the voltage is collapsing. The >> voltage collapse is not immediate because there is a significant >> capacitance across the LED string after the source resistance >> (which may be the current sense resistor). >>> >>> Nailed it! The expected curves now appear. Yet, my original current >>> curves are flawless. Filament faffing finally pays off. Uninhibited >>> brainstorming, no matter how insane it is in the interim, imparts >>> insight. Next clue: Bob Pease. > >Larkin's correct about one thing. The filament's intrinsic capacitance >does not play a role in the observed phase shift. > When the last paragraph says "expected curves" it means current >curves with zero phase shift relative to voltage. The voltage and current >relationship is totally resistive, as expected. > >While perusing TROUBLESHOOTING ANALOG CIRCUITS by Bob Pease for my next >hint, it occured to me how Larkin is the anti-Pease. And it goes a long >way in explaining Larkin's frequent battles with the late, great Jim >Thompson. > >Danke, My "battles" with JT were sporting. Pease lived near me, on Miramar Av. I met him several times. He was friendly and sold his and Jim Williams' books out of his house. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> |
|---|---|
| Date | 2026-04-24 18:30 +0000 |
| Message-ID | <10sgcsk$9fsl$1@dont-email.me> |
| In reply to | #743323 |
Don <g@crcomp.net> wrote: > John R Walliker <jrwalliker@gmail.com> wrote: >> On 24/04/2026 03:53, Don wrote: >>> Don <g@crcomp.net> wrote: >>>> Don wrote: >>>> >>>> <snip> >>>> >>>>> It's time for a brain teaser to >>>>> get things back on track. Put on your quantitative instincts hat and >>>>> take a good long look at all of the images shown at: >>>>> >>>>> <https://crcomp.net/ledfilament/index.php> >>>>> >>>>> Now put on your thinking cap. There's something glaringly wrong (so to >>>>> speak) with the experiment. It may explain the phase difference >>>>> discrepancy. Stay tuned. >>>> >>>> Alright you guys, this thread's fun again! There's yet another >>>> intuitively obvious source of error for those with quantitative >>>> instinctive eyes to see. And it has nothing whatsoever to do with my >>>> 320 VACp-p typo. Hint: imagine how my empirical current curves could >>>> be correct. >> >> The LED string does not begin to conduct until the peak voltage has >> been reached. Then the current increases abruptly and the voltage >> collapses due to a relatively high source impedance. The string >> continues to conduct even as the voltage is collapsing. The >> voltage collapse is not immediate because there is a significant >> capacitance across the LED string after the source resistance >> (which may be the current sense resistor). >>> >>> Nailed it! The expected curves now appear. Yet, my original current >>> curves are flawless. Filament faffing finally pays off. Uninhibited >>> brainstorming, no matter how insane it is in the interim, imparts >>> insight. Next clue: Bob Pease. > > Larkin's correct about one thing. The filament's intrinsic capacitance > does not play a role in the observed phase shift. > When the last paragraph says "expected curves" it means current > curves with zero phase shift relative to voltage. The voltage and current > relationship is totally resistive, as expected. > > While perusing TROUBLESHOOTING ANALOG CIRCUITS by Bob Pease for my next > hint, it occured to me how Larkin is the anti-Pease. And it goes a long > way in explaining Larkin's frequent battles with the late, great Jim > Thompson. > > Jim, may God hold him in memory eternal, repeatedly impugned the moral character of John’s delightful wife, as well as John’s own. Something about having been in a sorority at Boston University, as I recall. (I guess in JT’s era they wouldn’t date MIT guys, or something.) Jim occasionally tried to pull me into it, because John and I are friends. A fine engineer, a flawed man. So many of us are like that. Another time, iirc, John refused a job to Bill Sloman. The echoes are still being heard. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-24 11:42 -0700 |
| Message-ID | <nbenuk91jp76a5re14nd2bgi74c9mj56cj@4ax.com> |
| In reply to | #743328 |
On Fri, 24 Apr 2026 18:30:45 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote: >Don <g@crcomp.net> wrote: >> John R Walliker <jrwalliker@gmail.com> wrote: >>> On 24/04/2026 03:53, Don wrote: >>>> Don <g@crcomp.net> wrote: >>>>> Don wrote: >>>>> >>>>> <snip> >>>>> >>>>>> It's time for a brain teaser to >>>>>> get things back on track. Put on your quantitative instincts hat and >>>>>> take a good long look at all of the images shown at: >>>>>> >>>>>> <https://crcomp.net/ledfilament/index.php> >>>>>> >>>>>> Now put on your thinking cap. There's something glaringly wrong (so to >>>>>> speak) with the experiment. It may explain the phase difference >>>>>> discrepancy. Stay tuned. >>>>> >>>>> Alright you guys, this thread's fun again! There's yet another >>>>> intuitively obvious source of error for those with quantitative >>>>> instinctive eyes to see. And it has nothing whatsoever to do with my >>>>> 320 VACp-p typo. Hint: imagine how my empirical current curves could >>>>> be correct. >>> >>> The LED string does not begin to conduct until the peak voltage has >>> been reached. Then the current increases abruptly and the voltage >>> collapses due to a relatively high source impedance. The string >>> continues to conduct even as the voltage is collapsing. The >>> voltage collapse is not immediate because there is a significant >>> capacitance across the LED string after the source resistance >>> (which may be the current sense resistor). >>>> >>>> Nailed it! The expected curves now appear. Yet, my original current >>>> curves are flawless. Filament faffing finally pays off. Uninhibited >>>> brainstorming, no matter how insane it is in the interim, imparts >>>> insight. Next clue: Bob Pease. >> >> Larkin's correct about one thing. The filament's intrinsic capacitance >> does not play a role in the observed phase shift. >> When the last paragraph says "expected curves" it means current >> curves with zero phase shift relative to voltage. The voltage and current >> relationship is totally resistive, as expected. >> >> While perusing TROUBLESHOOTING ANALOG CIRCUITS by Bob Pease for my next >> hint, it occured to me how Larkin is the anti-Pease. And it goes a long >> way in explaining Larkin's frequent battles with the late, great Jim >> Thompson. >> >> > >Jim, may God hold him in memory eternal, repeatedly impugned the moral >character of John’s delightful wife, as well as John’s own. > >Something about having been in a sorority at Boston University, as I >recall. (I guess in JT’s era they wouldn’t date MIT guys, or something.) > >Jim occasionally tried to pull me into it, because John and I are friends. >A fine engineer, a flawed man. So many of us are like that. > >Another time, iirc, John refused a job to Bill Sloman. > >The echoes are still being heard. > >Cheers > >Phil Hobbs People are the least reliable components that we use. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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