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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
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| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-12 05:34 +0000 |
| Subject | CoB LED filament analysis |
| Message-ID | <20260411a@crcomp.net> |
Recent thread topic transitioned to a tentative opinion on a work-in-
progress webpage:
<https://crcomp.net/ledfilament/index.php>
Radiography imparts interesting insight. Second opinions welcome!
The current waveform flopped. Any advice on how to use a Fluke
80i-1000s connected to a Tek 2465B to display the 120 VAC current
wave is appreciated in advance. Also, what does "P2 < P1" signify on
the current probe?
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/kb7rpu vos |
[toc] | [next] | [standalone]
| From | JM <sunaecoNoChoppedPork@gmail.com> |
|---|---|
| Date | 2026-04-12 10:45 +0100 |
| Message-ID | <9opmtkdtmr46ub21iq6p8bu9p6qbmjhb7g@4ax.com> |
| In reply to | #742925 |
On Sun, 12 Apr 2026 05:34:48 -0000 (UTC), "Don" <g@crcomp.net> wrote: >wave is appreciated in advance. Also, what does "P2 < P1" signify on >the current probe? No idea. Can you just put a resistor in series and do a A-B on the scope? It looks like there are just a couple of resistors in series with the LED's. If the current waveform follows the voltage supply after the LEDs start conducting that points to a resistor to provide current limiting. If it was something active it would reach the current limit and stay there. Check if the current is supplied in pulses, indicating no supply smoothing. If these are high intensity LEDs they may only need a mA or two to provide adequate illumination. Most of the silicon drivers are simply a LDO regulator with a depletion MOSFET wrapped around it, with an enable input on the regulator so that the intensity can be controlled by a PWM signal.
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| From | JM <sunaecoNoChoppedPork@gmail.com> |
|---|---|
| Date | 2026-04-12 10:48 +0100 |
| Message-ID | <1gqmtkdtda9ro27gburi0nj3u741gu5g80@4ax.com> |
| In reply to | #742931 |
On Sun, 12 Apr 2026 10:45:45 +0100, JM <sunaecoNoChoppedPork@gmail.com> wrote: >>wave is appreciated in advance. Also, what does "P2 < P1" signify on >>the current probe? There's a fellow on Youtube (HairyDave) who tears down a lot of COB displays, it might be worth checking if he's had a lokk at one like your's.
[toc] | [prev] | [next] | [standalone]
| From | JM <sunaecoNoChoppedPork@gmail.com> |
|---|---|
| Date | 2026-04-12 10:50 +0100 |
| Message-ID | <jjqmtkl97s06ot489e05g4jv53ro501let@4ax.com> |
| In reply to | #742932 |
On Sun, 12 Apr 2026 10:48:05 +0100, JM <sunaecoNoChoppedPork@gmail.com> wrote: >There's a fellow on Youtube (HairyDave) who tears down a lot of COB >displays, it might be worth checking if he's had a lokk at one like >your's. Sorry - should be bigclivedotcom. (Although he is hairy as well as big...)
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| From | JM <sunaecoNoChoppedPork@gmail.com> |
|---|---|
| Date | 2026-04-12 12:03 +0100 |
| Message-ID | <6uumtkto1rrvvl2rr0d3gd4tnn7c0bnohk@4ax.com> |
| In reply to | #742933 |
On Sun, 12 Apr 2026 10:50:18 +0100, JM <sunaecoNoChoppedPork@gmail.com> wrote: >On Sun, 12 Apr 2026 10:48:05 +0100, JM ><sunaecoNoChoppedPork@gmail.com> wrote: > >>There's a fellow on Youtube (HairyDave) who tears down a lot of COB >>displays, it might be worth checking if he's had a lokk at one like >>your's. > > >Sorry - should be bigclivedotcom. (Although he is hairy as well as >big...) https://www.youtube.com/watch?v=hFtfMtFSD8A Somewhat similar to your devices, although twice as many LEDs.
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-12 04:44 -0700 |
| Message-ID | <8a1ntkl72f7hc5nug4uv43mllf3v72oeja@4ax.com> |
| In reply to | #742935 |
On Sun, 12 Apr 2026 12:03:10 +0100, JM <sunaecoNoChoppedPork@gmail.com> wrote: >On Sun, 12 Apr 2026 10:50:18 +0100, JM ><sunaecoNoChoppedPork@gmail.com> wrote: > >>On Sun, 12 Apr 2026 10:48:05 +0100, JM >><sunaecoNoChoppedPork@gmail.com> wrote: >> >>>There's a fellow on Youtube (HairyDave) who tears down a lot of COB >>>displays, it might be worth checking if he's had a lokk at one like >>>your's. >> >> >>Sorry - should be bigclivedotcom. (Although he is hairy as well as >>big...) > >https://www.youtube.com/watch?v=hFtfMtFSD8A > >Somewhat similar to your devices, although twice as many LEDs. Why not just slap it across the AC line? John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-12 04:19 -0700 |
| Message-ID | <5fumtklkdb75bhq3lcl5mure7hpjec604h@4ax.com> |
| In reply to | #742925 |
On Sun, 12 Apr 2026 05:34:48 -0000 (UTC), "Don" <g@crcomp.net> wrote: >Recent thread topic transitioned to a tentative opinion on a work-in- >progress webpage: > ><https://crcomp.net/ledfilament/index.php> > >Radiography imparts interesting insight. Second opinions welcome! > The current waveform flopped. Any advice on how to use a Fluke >80i-1000s connected to a Tek 2465B to display the 120 VAC current >wave is appreciated in advance. Also, what does "P2 < P1" signify on >the current probe? Very cool. Thanks. I suspect that the things on the end are resistors. If so, the current waveform will be low duty-cycle rounded bumps. Might be half-wave. Run it between AC hot and ground. Put a resistor in the low side and scope the voltage across it. Try 10 or 100 ohms maybe. That's perfectly safe. The current will be low enough that that beast of a 1000 amp current probe won't even notice it. A thermal image would be interesting. If I had one, I could thermal image it, measure the current waveform, and do a high-res Xray with our big Nikon. https://www.dropbox.com/scl/fi/cclxwf3tc9clw9m9jvafk/1.jpg?rlkey=j1zbtkbi80aam9rqi6vxpmwd6&raw=1 https://www.dropbox.com/scl/fi/mypyqavmr7fou52hytpz4/9-max-zoom.jpg?rlkey=w1eczzenyl1cl2m6yupbflrgt&raw=1 Geez, somebody manufactures these things for pennies. https://www.amazon.com/TJOY-Equivalent-Dimmable-Decorative-Filament/dp/B0B5KXBSLP https://www.youtube.com/watch?v=IKUGKQ-EUtM John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | piglet <erichpwagner@hotmail.com> |
|---|---|
| Date | 2026-04-13 07:40 +0000 |
| Message-ID | <10ri6ll$34rpp$1@dont-email.me> |
| In reply to | #742925 |
Don <g@crcomp.net> wrote: > Recent thread topic transitioned to a tentative opinion on a work-in- > progress webpage: > > <https://crcomp.net/ledfilament/index.php> > > Radiography imparts interesting insight. Second opinions welcome! > The current waveform flopped. Any advice on how to use a Fluke > 80i-1000s connected to a Tek 2465B to display the 120 VAC current > wave is appreciated in advance. Also, what does "P2 < P1" signify on > the current probe? > > -- > 73, Don, WD7Q veritas _|_ > liberabit | > https://www.qsl.net/kb7rpu vos | > > Looks like radiograph shows resistors at each end. Each resistor connects to two wire bonded diode chips then a series string of seven led chips. So basically seven LEDs inside a bridge rectifier with series resistors to limit current. -- piglet
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-13 01:46 -0700 |
| Message-ID | <76bptkt0snst4e4ui156gh76ij4mlu4vdm@4ax.com> |
| In reply to | #742977 |
On Mon, 13 Apr 2026 07:40:37 -0000 (UTC), piglet <erichpwagner@hotmail.com> wrote: >Don <g@crcomp.net> wrote: >> Recent thread topic transitioned to a tentative opinion on a work-in- >> progress webpage: >> >> <https://crcomp.net/ledfilament/index.php> >> >> Radiography imparts interesting insight. Second opinions welcome! >> The current waveform flopped. Any advice on how to use a Fluke >> 80i-1000s connected to a Tek 2465B to display the 120 VAC current >> wave is appreciated in advance. Also, what does "P2 < P1" signify on >> the current probe? >> >> -- >> 73, Don, WD7Q veritas _|_ >> liberabit | >> https://www.qsl.net/kb7rpu vos | >> >> > >Looks like radiograph shows resistors at each end. Each resistor connects >to two wire bonded diode chips then a series string of seven led chips. So >basically seven LEDs inside a bridge rectifier with series resistors to >limit current. Likely no rectifier and more than seven LEDs. The current waveform would reveal much. Or a couple of DC V-I curves. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | piglet <erichpwagner@hotmail.com> |
|---|---|
| Date | 2026-04-13 11:40 +0000 |
| Message-ID | <10rikn2$3923u$1@dont-email.me> |
| In reply to | #742983 |
john larkin <jl@glen--canyon.com> wrote: > On Mon, 13 Apr 2026 07:40:37 -0000 (UTC), piglet > <erichpwagner@hotmail.com> wrote: > >> Don <g@crcomp.net> wrote: >>> Recent thread topic transitioned to a tentative opinion on a work-in- >>> progress webpage: >>> >>> <https://crcomp.net/ledfilament/index.php> >>> >>> Radiography imparts interesting insight. Second opinions welcome! >>> The current waveform flopped. Any advice on how to use a Fluke >>> 80i-1000s connected to a Tek 2465B to display the 120 VAC current >>> wave is appreciated in advance. Also, what does "P2 < P1" signify on >>> the current probe? >>> >>> -- >>> 73, Don, WD7Q veritas _|_ >>> liberabit | >>> https://www.qsl.net/kb7rpu vos | >>> >>> >> >> Looks like radiograph shows resistors at each end. Each resistor connects >> to two wire bonded diode chips then a series string of seven led chips. So >> basically seven LEDs inside a bridge rectifier with series resistors to >> limit current. > > Likely no rectifier and more than seven LEDs. The current waveform > would reveal much. Or a couple of DC V-I curves. > > > John Larkin > Highland Tech Glen Canyon Design Center > Lunatic Fringe Electronics > The diodes are visible next the resistors even the bond wires are faintly visible in the photo. -- piglet
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| From | JM <sunaecoNoChoppedPork@gmail.com> |
|---|---|
| Date | 2026-04-13 14:31 +0100 |
| Message-ID | <1urptkdi5gicce55ke373nf5u3eofef9tb@4ax.com> |
| In reply to | #742989 |
>The diodes are visible next the resistors even the bond wires are faintly >visible in the photo. You are probably correct, but easy enough for Don to check by using a DC supply to check conduction with both polarities. -- This email has been checked for viruses by Avast antivirus software. www.avast.com
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-13 06:59 -0700 |
| Message-ID | <ektptkl4npqhqv53th7q90caaemk8j84sr@4ax.com> |
| In reply to | #742991 |
On Mon, 13 Apr 2026 14:31:25 +0100, JM <sunaecoNoChoppedPork@gmail.com> wrote: >>The diodes are visible next the resistors even the bond wires are faintly >>visible in the photo. > >You are probably correct, but easy enough for Don to check by using a >DC supply to check conduction with both polarities. Yes. Graph and don't guess. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | "Don" <g@crcomp.net> |
|---|---|
| Date | 2026-04-14 12:25 +0000 |
| Message-ID | <20260414a@crcomp.net> |
| In reply to | #742993 |
john larkin wrote:
> JM wrote:
>
>>>The diodes are visible next the resistors even the bond wires are faintly
>>>visible in the photo.
>>
>>You are probably correct, but easy enough for Don to check by using a
>>DC supply to check conduction with both polarities.
>
> Yes. Graph and don't guess.
OK you guys, lots of excellent ideas! The DC idea's easiest, so it's
first. Big Clive's youtube link now appears as a Footnote on the
pertinent page:
<https://crcomp.net/ledfilament/index.php>
The webpage also includes a couple of new images where 68 VDC is applied
to barely illuminate the filament's CoBs, first in one direction, and
then the opposite. How do you graph such empirical data?
Anyhow, as expected, seven filament CoBs illuminate regardless of
DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs,
cross connected to conduct current through the anode of one LED, while
the cathode of its coupled LED blocks current?
JM, elsewhere you mention fourteen illuminated CoBs in Big Clive's
video. It seems significant that fourteen CoBs are also illuminated in
my filament (seven for each DC polarity).
The filament also contains a small hole on one lead to denote its
anode. But it's pointless because the filament conducts in either
direction.
Does one factory in China create CoB filaments for both AC and DC
applications? So users end up with filaments filled with fourteen CoBs
and an anode hole in one lead?
--
73, Don, WD7Q veritas _|_
liberabit |
https://www.qsl.net/wd7q vos |
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| From | JM <sunaecoNoChoppedPork@gmail.com> |
|---|---|
| Date | 2026-04-14 14:04 +0100 |
| Message-ID | <9iestk9fkchtjebr8inr8st59lpd0m41hr@4ax.com> |
| In reply to | #743017 |
On Tue, 14 Apr 2026 12:25:57 -0000 (UTC), "Don" <g@crcomp.net> wrote: >john larkin wrote: >> JM wrote: >> >>>>The diodes are visible next the resistors even the bond wires are faintly >>>>visible in the photo. >>> >>>You are probably correct, but easy enough for Don to check by using a >>>DC supply to check conduction with both polarities. >> >> Yes. Graph and don't guess. > >OK you guys, lots of excellent ideas! The DC idea's easiest, so it's >first. Big Clive's youtube link now appears as a Footnote on the >pertinent page: > > <https://crcomp.net/ledfilament/index.php> > >The webpage also includes a couple of new images where 68 VDC is applied >to barely illuminate the filament's CoBs, first in one direction, and >then the opposite. How do you graph such empirical data? > Anyhow, as expected, seven filament CoBs illuminate regardless of >DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs, >cross connected to conduct current through the anode of one LED, while >the cathode of its coupled LED blocks current? > JM, elsewhere you mention fourteen illuminated CoBs in Big Clive's >video. It seems significant that fourteen CoBs are also illuminated in >my filament (seven for each DC polarity). > The filament also contains a small hole on one lead to denote its >anode. But it's pointless because the filament conducts in either >direction. > Does one factory in China create CoB filaments for both AC and DC >applications? So users end up with filaments filled with fourteen CoBs >and an anode hole in one lead? No, you only have seven LEDs - they always see the same polarity due to the diode bridge (which you have proved to exist). The lamp in the hairyones video is a chinese knock off of the Osram GW T3LSF2.DM https://ams-osram.com/products/leds/white-leds/osram-duris-l-38-gw-t3lsf2-dm which is just a stack of (18) LEDs with no bridge or current limiting. Your device has a bridge and current limiting resistors inbuilt, something like the sketch at 2.36m in the youtube video.
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-14 08:21 -0700 |
| Message-ID | <64mstkhuv9792mr44ac6fo6ks9355v53uq@4ax.com> |
| In reply to | #743017 |
On Tue, 14 Apr 2026 12:25:57 -0000 (UTC), "Don" <g@crcomp.net> wrote: >john larkin wrote: >> JM wrote: >> >>>>The diodes are visible next the resistors even the bond wires are faintly >>>>visible in the photo. >>> >>>You are probably correct, but easy enough for Don to check by using a >>>DC supply to check conduction with both polarities. >> >> Yes. Graph and don't guess. > >OK you guys, lots of excellent ideas! The DC idea's easiest, so it's >first. Big Clive's youtube link now appears as a Footnote on the >pertinent page: > > <https://crcomp.net/ledfilament/index.php> > >The webpage also includes a couple of new images where 68 VDC is applied >to barely illuminate the filament's CoBs, first in one direction, and >then the opposite. How do you graph such empirical data? > Anyhow, as expected, seven filament CoBs illuminate regardless of >DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs, >cross connected to conduct current through the anode of one LED, while >the cathode of its coupled LED blocks current? The xray sure doesn't look like there is a bridge rectifier. https://crcomp.net/ledfilament/top.png so I expect the LEDs are connected antiparallel. If 68v is the turnon threshold, and a blue LED needs, say 2.8 to light up a bit, there are roughly 24 LEDs in series. What someone should do is graph current vs voltage, both polarities. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | Bill Sloman <bill.sloman@ieee.org> |
|---|---|
| Date | 2026-04-15 02:48 +1000 |
| Message-ID | <10rlr5v$88jv$1@dont-email.me> |
| In reply to | #743021 |
On 15/04/2026 1:21 am, john larkin wrote: > On Tue, 14 Apr 2026 12:25:57 -0000 (UTC), "Don" <g@crcomp.net> wrote: > >> john larkin wrote: >>> JM wrote: >>> >>>>> The diodes are visible next the resistors even the bond wires are faintly >>>>> visible in the photo. >>>> >>>> You are probably correct, but easy enough for Don to check by using a >>>> DC supply to check conduction with both polarities. >>> >>> Yes. Graph and don't guess. >> >> OK you guys, lots of excellent ideas! The DC idea's easiest, so it's >> first. Big Clive's youtube link now appears as a Footnote on the >> pertinent page: >> >> <https://crcomp.net/ledfilament/index.php> >> >> The webpage also includes a couple of new images where 68 VDC is applied >> to barely illuminate the filament's CoBs, first in one direction, and >> then the opposite. How do you graph such empirical data? >> Anyhow, as expected, seven filament CoBs illuminate regardless of >> DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs, >> cross connected to conduct current through the anode of one LED, while >> the cathode of its coupled LED blocks current? > > The xray sure doesn't look like there is a bridge rectifier. The four rectifiers creating the bridge rectifier may not be mounted together as a discrete bridge rectifier, but that doesn't stop them working together to create the same effect. > https://crcomp.net/ledfilament/top.png > > so I expect the LEDs are connected antiparallel. That would mean twice as many LEDs, which would be a much more expensive solution. > If 68v is the turnon threshold, and a blue LED needs, say 2.8 to light > up a bit, there are roughly 24 LEDs in series. There might be, if anybody could see them on the X-rays. Google says that blue LED drop between 3.0V and 3.4V. Seven of the them would drop between 21 and 24 V and enough resistance to soak up the remaining 44V would make the current tolerably stable against self-heating in the LEDs (whose forward voltage drops as the junction temperature increases). https://descargas.cetronic.es/WW05A3SBQ4-N.pdf > What someone should do is graph current vs voltage, both polarities. What John Larkin needs to do is to think a bit harder. -- Bill Sloman, Sydney
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| From | john larkin <jl@glen--canyon.com> |
|---|---|
| Date | 2026-04-14 11:14 -0700 |
| Message-ID | <1i0ttkdrpdkal9m4mlbrpb9t4tuo7tc0fo@4ax.com> |
| In reply to | #743022 |
On Wed, 15 Apr 2026 02:48:59 +1000, Bill Sloman <bill.sloman@ieee.org> wrote: >On 15/04/2026 1:21 am, john larkin wrote: >> On Tue, 14 Apr 2026 12:25:57 -0000 (UTC), "Don" <g@crcomp.net> wrote: >> >>> john larkin wrote: >>>> JM wrote: >>>> >>>>>> The diodes are visible next the resistors even the bond wires are faintly >>>>>> visible in the photo. >>>>> >>>>> You are probably correct, but easy enough for Don to check by using a >>>>> DC supply to check conduction with both polarities. >>>> >>>> Yes. Graph and don't guess. >>> >>> OK you guys, lots of excellent ideas! The DC idea's easiest, so it's >>> first. Big Clive's youtube link now appears as a Footnote on the >>> pertinent page: >>> >>> <https://crcomp.net/ledfilament/index.php> >>> >>> The webpage also includes a couple of new images where 68 VDC is applied >>> to barely illuminate the filament's CoBs, first in one direction, and >>> then the opposite. How do you graph such empirical data? >>> Anyhow, as expected, seven filament CoBs illuminate regardless of >>> DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs, >>> cross connected to conduct current through the anode of one LED, while >>> the cathode of its coupled LED blocks current? >> >> The xray sure doesn't look like there is a bridge rectifier. > >The four rectifiers creating the bridge rectifier may not be mounted >together as a discrete bridge rectifier, but that doesn't stop them >working together to create the same effect. > >> https://crcomp.net/ledfilament/top.png >> >> so I expect the LEDs are connected antiparallel. > >That would mean twice as many LEDs, which would be a much more expensive >solution. There's no obvious bridge in the xray, but resolution isn't very good. There are ways to decap a plastic-potted IC. > >> If 68v is the turnon threshold, and a blue LED needs, say 2.8 to light >> up a bit, there are roughly 24 LEDs in series. > >There might be, if anybody could see them on the X-rays. Google says >that blue LED drop between 3.0V and 3.4V. Seven of the them would drop >between 21 and 24 V and enough resistance to soak up the remaining 44V >would make the current tolerably stable against self-heating in the LEDs >(whose forward voltage drops as the junction temperature increases). > >https://descargas.cetronic.es/WW05A3SBQ4-N.pdf Look at the V-I curve on that part. It conducts 1 mA at about 2.8 volts, and would be visible at way lower current. 1 uA might be visible in dim room light. > >> What someone should do is graph current vs voltage, both polarities. > >What John Larkin needs to do is to think a bit harder. Well, I do have a day job. John Larkin Highland Tech Glen Canyon Design Center Lunatic Fringe Electronics
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| From | piglet <erichpwagner@hotmail.com> |
|---|---|
| Date | 2026-04-14 19:25 +0100 |
| Message-ID | <10rm0q4$a340$1@dont-email.me> |
| In reply to | #743023 |
On 14/04/2026 7:14 pm, john larkin wrote: > On Wed, 15 Apr 2026 02:48:59 +1000, Bill Sloman <bill.sloman@ieee.org> > wrote: > >> On 15/04/2026 1:21 am, john larkin wrote: >>> On Tue, 14 Apr 2026 12:25:57 -0000 (UTC), "Don" <g@crcomp.net> wrote: >>> >>>> john larkin wrote: >>>>> JM wrote: >>>>> >>>>>>> The diodes are visible next the resistors even the bond wires are faintly >>>>>>> visible in the photo. >>>>>> >>>>>> You are probably correct, but easy enough for Don to check by using a >>>>>> DC supply to check conduction with both polarities. >>>>> >>>>> Yes. Graph and don't guess. >>>> >>>> OK you guys, lots of excellent ideas! The DC idea's easiest, so it's >>>> first. Big Clive's youtube link now appears as a Footnote on the >>>> pertinent page: >>>> >>>> <https://crcomp.net/ledfilament/index.php> >>>> >>>> The webpage also includes a couple of new images where 68 VDC is applied >>>> to barely illuminate the filament's CoBs, first in one direction, and >>>> then the opposite. How do you graph such empirical data? >>>> Anyhow, as expected, seven filament CoBs illuminate regardless of >>>> DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs, >>>> cross connected to conduct current through the anode of one LED, while >>>> the cathode of its coupled LED blocks current? >>> >>> The xray sure doesn't look like there is a bridge rectifier. >> >> The four rectifiers creating the bridge rectifier may not be mounted >> together as a discrete bridge rectifier, but that doesn't stop them >> working together to create the same effect. >> >>> https://crcomp.net/ledfilament/top.png >>> >>> so I expect the LEDs are connected antiparallel. >> >> That would mean twice as many LEDs, which would be a much more expensive >> solution. > > There's no obvious bridge in the xray, but resolution isn't very good. > > There are ways to decap a plastic-potted IC. > >> >>> If 68v is the turnon threshold, and a blue LED needs, say 2.8 to light >>> up a bit, there are roughly 24 LEDs in series. >> >> There might be, if anybody could see them on the X-rays. Google says >> that blue LED drop between 3.0V and 3.4V. Seven of the them would drop >> between 21 and 24 V and enough resistance to soak up the remaining 44V >> would make the current tolerably stable against self-heating in the LEDs >> (whose forward voltage drops as the junction temperature increases). >> >> https://descargas.cetronic.es/WW05A3SBQ4-N.pdf > > Look at the V-I curve on that part. It conducts 1 mA at about 2.8 > volts, and would be visible at way lower current. 1 uA might be > visible in dim room light. > >> >>> What someone should do is graph current vs voltage, both polarities. >> >> What John Larkin needs to do is to think a bit harder. > > Well, I do have a day job. > > > John Larkin > Highland Tech Glen Canyon Design Center > Lunatic Fringe Electronics Can you see the four diodes now ...? <https://www.dropbox.com/scl/fi/4kcz56xykw1780z3qad3w/COB_LED.pdf?rlkey=b5mz77rs8pbwzv7bt9n5sfae3&st=x8h1gsgq&raw=1> piglet
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| From | JM <sunaecoNoChoppedPork@gmail.com> |
|---|---|
| Date | 2026-04-14 19:43 +0100 |
| Message-ID | <nl2ttkl8dgng9p26gr9dhu8mpe5gi1smld@4ax.com> |
| In reply to | #743024 |
On Tue, 14 Apr 2026 19:25:07 +0100, piglet <erichpwagner@hotmail.com> wrote: >On 14/04/2026 7:14 pm, john larkin wrote: >> On Wed, 15 Apr 2026 02:48:59 +1000, Bill Sloman <bill.sloman@ieee.org> >> wrote: >> >>> On 15/04/2026 1:21 am, john larkin wrote: >>>> On Tue, 14 Apr 2026 12:25:57 -0000 (UTC), "Don" <g@crcomp.net> wrote: >>>> >>>>> john larkin wrote: >>>>>> JM wrote: >>>>>> >>>>>>>> The diodes are visible next the resistors even the bond wires are faintly >>>>>>>> visible in the photo. >>>>>>> >>>>>>> You are probably correct, but easy enough for Don to check by using a >>>>>>> DC supply to check conduction with both polarities. >>>>>> >>>>>> Yes. Graph and don't guess. >>>>> >>>>> OK you guys, lots of excellent ideas! The DC idea's easiest, so it's >>>>> first. Big Clive's youtube link now appears as a Footnote on the >>>>> pertinent page: >>>>> >>>>> <https://crcomp.net/ledfilament/index.php> >>>>> >>>>> The webpage also includes a couple of new images where 68 VDC is applied >>>>> to barely illuminate the filament's CoBs, first in one direction, and >>>>> then the opposite. How do you graph such empirical data? >>>>> Anyhow, as expected, seven filament CoBs illuminate regardless of >>>>> DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs, >>>>> cross connected to conduct current through the anode of one LED, while >>>>> the cathode of its coupled LED blocks current? >>>> >>>> The xray sure doesn't look like there is a bridge rectifier. >>> >>> The four rectifiers creating the bridge rectifier may not be mounted >>> together as a discrete bridge rectifier, but that doesn't stop them >>> working together to create the same effect. >>> >>>> https://crcomp.net/ledfilament/top.png >>>> >>>> so I expect the LEDs are connected antiparallel. >>> >>> That would mean twice as many LEDs, which would be a much more expensive >>> solution. >> >> There's no obvious bridge in the xray, but resolution isn't very good. >> >> There are ways to decap a plastic-potted IC. >> >>> >>>> If 68v is the turnon threshold, and a blue LED needs, say 2.8 to light >>>> up a bit, there are roughly 24 LEDs in series. >>> >>> There might be, if anybody could see them on the X-rays. Google says >>> that blue LED drop between 3.0V and 3.4V. Seven of the them would drop >>> between 21 and 24 V and enough resistance to soak up the remaining 44V >>> would make the current tolerably stable against self-heating in the LEDs >>> (whose forward voltage drops as the junction temperature increases). >>> >>> https://descargas.cetronic.es/WW05A3SBQ4-N.pdf >> >> Look at the V-I curve on that part. It conducts 1 mA at about 2.8 >> volts, and would be visible at way lower current. 1 uA might be >> visible in dim room light. >> >>> >>>> What someone should do is graph current vs voltage, both polarities. >>> >>> What John Larkin needs to do is to think a bit harder. >> >> Well, I do have a day job. >> >> >> John Larkin >> Highland Tech Glen Canyon Design Center >> Lunatic Fringe Electronics > > >Can you see the four diodes now ...? > ><https://www.dropbox.com/scl/fi/4kcz56xykw1780z3qad3w/COB_LED.pdf?rlkey=b5mz77rs8pbwzv7bt9n5sfae3&st=x8h1gsgq&raw=1> > >piglet You beat me to it. -- This email has been checked for viruses by Avast antivirus software. www.avast.com
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| From | piglet <erichpwagner@hotmail.com> |
|---|---|
| Date | 2026-04-14 20:19 +0000 |
| Message-ID | <10rm7hf$dmgn$1@dont-email.me> |
| In reply to | #743026 |
JM <sunaecoNoChoppedPork@gmail.com> wrote: > On Tue, 14 Apr 2026 19:25:07 +0100, piglet <erichpwagner@hotmail.com> > wrote: > >> On 14/04/2026 7:14 pm, john larkin wrote: >>> On Wed, 15 Apr 2026 02:48:59 +1000, Bill Sloman <bill.sloman@ieee.org> >>> wrote: >>> >>>> On 15/04/2026 1:21 am, john larkin wrote: >>>>> On Tue, 14 Apr 2026 12:25:57 -0000 (UTC), "Don" <g@crcomp.net> wrote: >>>>> >>>>>> john larkin wrote: >>>>>>> JM wrote: >>>>>>> >>>>>>>>> The diodes are visible next the resistors even the bond wires are faintly >>>>>>>>> visible in the photo. >>>>>>>> >>>>>>>> You are probably correct, but easy enough for Don to check by using a >>>>>>>> DC supply to check conduction with both polarities. >>>>>>> >>>>>>> Yes. Graph and don't guess. >>>>>> >>>>>> OK you guys, lots of excellent ideas! The DC idea's easiest, so it's >>>>>> first. Big Clive's youtube link now appears as a Footnote on the >>>>>> pertinent page: >>>>>> >>>>>> <https://crcomp.net/ledfilament/index.php> >>>>>> >>>>>> The webpage also includes a couple of new images where 68 VDC is applied >>>>>> to barely illuminate the filament's CoBs, first in one direction, and >>>>>> then the opposite. How do you graph such empirical data? >>>>>> Anyhow, as expected, seven filament CoBs illuminate regardless of >>>>>> DC polarity. Perhaps each of the seven CoBs contains a couple of LEDs, >>>>>> cross connected to conduct current through the anode of one LED, while >>>>>> the cathode of its coupled LED blocks current? >>>>> >>>>> The xray sure doesn't look like there is a bridge rectifier. >>>> >>>> The four rectifiers creating the bridge rectifier may not be mounted >>>> together as a discrete bridge rectifier, but that doesn't stop them >>>> working together to create the same effect. >>>> >>>>> https://crcomp.net/ledfilament/top.png >>>>> >>>>> so I expect the LEDs are connected antiparallel. >>>> >>>> That would mean twice as many LEDs, which would be a much more expensive >>>> solution. >>> >>> There's no obvious bridge in the xray, but resolution isn't very good. >>> >>> There are ways to decap a plastic-potted IC. >>> >>>> >>>>> If 68v is the turnon threshold, and a blue LED needs, say 2.8 to light >>>>> up a bit, there are roughly 24 LEDs in series. >>>> >>>> There might be, if anybody could see them on the X-rays. Google says >>>> that blue LED drop between 3.0V and 3.4V. Seven of the them would drop >>>> between 21 and 24 V and enough resistance to soak up the remaining 44V >>>> would make the current tolerably stable against self-heating in the LEDs >>>> (whose forward voltage drops as the junction temperature increases). >>>> >>>> https://descargas.cetronic.es/WW05A3SBQ4-N.pdf >>> >>> Look at the V-I curve on that part. It conducts 1 mA at about 2.8 >>> volts, and would be visible at way lower current. 1 uA might be >>> visible in dim room light. >>> >>>> >>>>> What someone should do is graph current vs voltage, both polarities. >>>> >>>> What John Larkin needs to do is to think a bit harder. >>> >>> Well, I do have a day job. >>> >>> >>> John Larkin >>> Highland Tech Glen Canyon Design Center >>> Lunatic Fringe Electronics >> >> >> Can you see the four diodes now ...? >> >> <https://www.dropbox.com/scl/fi/4kcz56xykw1780z3qad3w/COB_LED.pdf?rlkey=b5mz77rs8pbwzv7bt9n5sfae3&st=x8h1gsgq&raw=1> >> >> piglet > > > You beat me to it. > Nice to know someone else could see them too! -- piglet
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