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On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43â¯AM UTC-4, John Larkin wrote:
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
spa...@not.com> wrote:
I recently changed the overhead fluorescent lamps for LED replacements.
Very soon, I noticed they were flickering a lot more the the old
fluorescents.
They flicker on the slightest line disturbance, from someone turning on a
microwave to who knows what outside the building. It turns out the
bandwidth of LEDs is much higher than gas lamps. Good to know if you\'re in
the spying business, but not good in the shop.
I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
On Friday, September 8, 2023 at 11:25:43?AM UTC-4, John Larkin wrote:
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
spa...@not.com> wrote:
I recently changed the overhead fluorescent lamps for LED replacements.
Very soon, I noticed they were flickering a lot more the the old
fluorescents.
They flicker on the slightest line disturbance, from someone turning on a
microwave to who knows what outside the building. It turns out the
bandwidth of LEDs is much higher than gas lamps. Good to know if you\'re in
the spying business, but not good in the shop.
I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
On Saturday, September 9, 2023 at 9:01:28?AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43?AM UTC-4, John Larkin wrote:
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
spa...@not.com> wrote:
I recently changed the overhead fluorescent lamps for LED replacements.
Very soon, I noticed they were flickering a lot more the the old
fluorescents.
They flicker on the slightest line disturbance, from someone turning on a
microwave to who knows what outside the building. It turns out the
bandwidth of LEDs is much higher than gas lamps. Good to know if you\'re in
the spying business, but not good in the shop.
I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
lørdag den 9. september 2023 kl. 16.11.50 UTC+2 skrev Fred Bloggs:
On Saturday, September 9, 2023 at 9:01:28?AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43?AM UTC-4, John Larkin wrote:
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
spa...@not.com> wrote:
I recently changed the overhead fluorescent lamps for LED replacements.
Very soon, I noticed they were flickering a lot more the the old
fluorescents.
They flicker on the slightest line disturbance, from someone turning on a
microwave to who knows what outside the building. It turns out the
bandwidth of LEDs is much higher than gas lamps. Good to know if you\'re in
the spying business, but not good in the shop.
I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
https://youtu.be/5HTa2jVi_rc?si=QA9pGKmg-w8iuZgb&t=243
https://youtu.be/klaJqofCsu4?si=Qbkys3CHIaJnYFq9
On Sat, 9 Sep 2023 07:21:18 -0700 (PDT), Lasse Langwadt Christensen
lang...@fonz.dk> wrote:
lørdag den 9. september 2023 kl. 16.11.50 UTC+2 skrev Fred Bloggs:
On Saturday, September 9, 2023 at 9:01:28?AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43?AM UTC-4, John Larkin wrote:
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
spa...@not.com> wrote:
I recently changed the overhead fluorescent lamps for LED replacements.
Very soon, I noticed they were flickering a lot more the the old
fluorescents.
They flicker on the slightest line disturbance, from someone turning on a
microwave to who knows what outside the building. It turns out the
bandwidth of LEDs is much higher than gas lamps. Good to know if you\'re in
the spying business, but not good in the shop.
I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
https://youtu.be/5HTa2jVi_rc?si=QA9pGKmg-w8iuZgb&t=243
https://youtu.be/klaJqofCsu4?si=Qbkys3CHIaJnYFq9
Does Philips still sell LED bulbs? They had some really good ones that
aren\'t available any more. I\'d expect they can\'t compete with the
Chinese stuff.
On Sat, 9 Sep 2023 07:11:44 -0700 (PDT), Fred Bloggs
bloggs.fred...@gmail.com> wrote:
On Saturday, September 9, 2023 at 9:01:28?AM UTC-4, Lasse Langwadt Christensen wrote:
lÅrdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43?AM UTC-4, John Larkin wrote:
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
spa...@not.com> wrote:
I recently changed the overhead fluorescent lamps for LED replacements.
Very soon, I noticed they were flickering a lot more the the old
fluorescents.
They flicker on the slightest line disturbance, from someone turning on a
microwave to who knows what outside the building. It turns out the
bandwidth of LEDs is much higher than gas lamps. Good to know if you\'re in
the spying business, but not good in the shop.
I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
Get a clear-glass Edison type LED lamp. You can see the parts down in
the base. There\'s no big cap, no inductor.
fredag den 8. september 2023 kl. 20.49.57 UTC+2 skrev Mike Monett VE3BTI:
legg <le...@nospam.magma.ca> wrote:
snip
The lED lamps contain their own bridge rectifier to convert the AC line
voltage to DC to drive the lamps.
snip
Mike, there are many fluorescent replacement types of LED lamp.
At this low (and usually fixed) power level, it\'s possible to
skin this cat any number of ways.
If you use a variac to evaluate brightness vs line voltage on
the lamps you are using, you\'ll see the range of voltages
required to perform the dimming function.
I think you\'ll be surprised at just how low these voltage
values can be and how narrow the adjustment range is.
Only types that are designed for dimming, or dimmers
designed for LEDs can give you satisfactory performance.
R4 . . . . this is one cat that isn\'t skinned properly.
RL
Thanks for your message.
I am interested in eliminating flicker due to line transients. A capacitor
stores energy and supplies it to the LED during a transient.
Ordinary dimmers are not intended to drive capacitors. This will be the
first time. I will have to see how they perform but I am pretty confident
they will work in this application.
I am not interested in actually dimming the light. I have a 0 - 300v supply
that I can use to see how the LED lamps perform with DC. I understand they
operate over a narrow range, much like a diode, as they are basically
current driven.
I agree with you. R4 may not be needed. I included it as I didn\'t know how
it would affect the operation of the circuit. Changing it to 1e6 ohms made
no difference.
most LED lamps have a build in constant current driver so they will be the same
brightness at any voltage high enough for the LEDs and regulation
or that they have a capacitive dropper that will only work on DC and have a terrible power factor
On Sat, 9 Sep 2023 05:46:43 -0700 (PDT), Fred Bloggs
bloggs.fred...@gmail.com> wrote:
On Friday, September 8, 2023 at 11:25:43?AM UTC-4, John Larkin wrote:
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
spa...@not.com> wrote:
I recently changed the overhead fluorescent lamps for LED replacements.
Very soon, I noticed they were flickering a lot more the the old
fluorescents.
They flicker on the slightest line disturbance, from someone turning on a
microwave to who knows what outside the building. It turns out the
bandwidth of LEDs is much higher than gas lamps. Good to know if you\'re in
the spying business, but not good in the shop.
I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
No, that\'s too expensive. Many have a current-limiting IC and no
energy storage. The current actually flows near the AC line peak.
On Sat, 9 Sep 2023 07:11:44 -0700 (PDT), Fred Bloggs
bloggs.fred...@gmail.com> wrote:
On Saturday, September 9, 2023 at 9:01:28?AM UTC-4, Lasse Langwadt Christensen wrote:
lÅrdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43?AM UTC-4, John Larkin wrote:
On Fri, 8 Sep 2023 08:10:41 -0000 (UTC), Mike Monett VE3BTI
spa...@not.com> wrote:
I recently changed the overhead fluorescent lamps for LED replacements.
Very soon, I noticed they were flickering a lot more the the old
fluorescents.
They flicker on the slightest line disturbance, from someone turning on a
microwave to who knows what outside the building. It turns out the
bandwidth of LEDs is much higher than gas lamps. Good to know if you\'re in
the spying business, but not good in the shop.
I doubt that the fluorescents are much slower, at visual speeds, than
LEDs. You can verify that with a photodetector and an ocilloscope.
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
Get a clear-glass Edison type LED lamp. You can see the parts down in
the base. There\'s no big cap, no inductor.
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
On Saturday, September 9, 2023 at 7:11:50â¯AM UTC-7, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
And consumer commodity bulbs don\'t have to be dirt cheap? These type lamps
https://www.ikea.com/us/en/p/solhetta-led-bulb-e26-450-lumen-globe-clear-10530117/
certainly are \'enough LEDs in series\' and not much else; there\'s no ROOM for more parts than that.
On Saturday, September 9, 2023 at 7:11:50â¯AM UTC-7, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
And consumer commodity bulbs don\'t have to be dirt cheap? These type lamps
https://www.ikea.com/us/en/p/solhetta-led-bulb-e26-450-lumen-globe-clear-10530117/
certainly are \'enough LEDs in series\' and not much else; there\'s no ROOM for more parts than that.
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43â¯AM UTC-4, John Larkin wrote:
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
On Saturday, September 9, 2023 at 7:40:53â¯PM UTC-4, whit3rd wrote:
On Saturday, September 9, 2023 at 7:11:50â¯AM UTC-7, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
And consumer commodity bulbs don\'t have to be dirt cheap? These type lamps
https://www.ikea.com/us/en/p/solhetta-led-bulb-e26-450-lumen-globe-clear-10530117/
certainly are \'enough LEDs in series\' and not much else; there\'s no ROOM for more parts than that.
It\'s probably grade F efficiency:
On 09/09/2023 15:11, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43â¯AM UTC-4, John Larkin wrote:
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
You are wrong. I have a dead one sat in a drawer somewhere nearby.
60 LEDs in series across rectified UK 240v mains.
One single LED in the chain has failed. It was the first LED bulb
failure that I ever saw so I dismantled it to see why.
They are the cheapest and nastiest on the market, but at the time it was
bought they sold for premium prices with exaggerated MTBF based on the
expected failure time of a single LED. True MTBF is claimed/60.
--
Martin Brown
søndag den 10. september 2023 kl. 16.44.38 UTC+2 skrev Fred Bloggs:
On Saturday, September 9, 2023 at 7:40:53â¯PM UTC-4, whit3rd wrote:
On Saturday, September 9, 2023 at 7:11:50â¯AM UTC-7, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
And consumer commodity bulbs don\'t have to be dirt cheap? These type lamps
https://www.ikea.com/us/en/p/solhetta-led-bulb-e26-450-lumen-globe-clear-10530117/
certainly are \'enough LEDs in series\' and not much else; there\'s no ROOM for more parts than that.
It\'s probably grade F efficiency:
it\'s grade C which in the pre 2020 rating would have been better than A++
On Sunday, September 10, 2023 at 11:10:59â¯AM UTC-4, Lasse Langwadt Christensen wrote:
søndag den 10. september 2023 kl. 16.44.38 UTC+2 skrev Fred Bloggs:
On Saturday, September 9, 2023 at 7:40:53â¯PM UTC-4, whit3rd wrote:
On Saturday, September 9, 2023 at 7:11:50â¯AM UTC-7, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
And consumer commodity bulbs don\'t have to be dirt cheap? These type lamps
https://www.ikea.com/us/en/p/solhetta-led-bulb-e26-450-lumen-globe-clear-10530117/
certainly are \'enough LEDs in series\' and not much else; there\'s no ROOM for more parts than that.
It\'s probably grade F efficiency:
it\'s grade C which in the pre 2020 rating would have been better than A++
That\'s not the Edison filament bulb. I didn\'t find one that he did on the Solhetta.
On Sunday, September 10, 2023 at 10:57:40â¯AM UTC-4, Martin Brown wrote:
On 09/09/2023 15:11, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43â¯AM UTC-4, John Larkin wrote:
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
You are wrong. I have a dead one sat in a drawer somewhere nearby.
60 LEDs in series across rectified UK 240v mains.
No one is interested in an example of degenerate ad hoc engineering that was completely abandoned, and for good reason.
One single LED in the chain has failed. It was the first LED bulb
failure that I ever saw so I dismantled it to see why.
They are the cheapest and nastiest on the market, but at the time it was
bought they sold for premium prices with exaggerated MTBF based on the
expected failure time of a single LED. True MTBF is claimed/60.
On 10/09/2023 16:18, Fred Bloggs wrote:
On Sunday, September 10, 2023 at 10:57:40â¯AM UTC-4, Martin Brown wrote:
On 09/09/2023 15:11, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
On Friday, September 8, 2023 at 11:25:43â¯AM UTC-4, John Larkin wrote:
Maybe you have cheap flourescent-replacement tubes.
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
You are wrong. I have a dead one sat in a drawer somewhere nearby.
60 LEDs in series across rectified UK 240v mains.
No one is interested in an example of degenerate ad hoc engineering that was completely abandoned, and for good reason.
They were made like that presumably to be as cheap and nasty as
possible. When they worked they were fine and instant on with true rated
brightness unlike the previous generation of CFLs which came on dimly
and almost never reached the brightness that their packaging claimed.
One single LED in the chain has failed. It was the first LED bulb
failure that I ever saw so I dismantled it to see why.
They are the cheapest and nastiest on the market, but at the time it was
bought they sold for premium prices with exaggerated MTBF based on the
expected failure time of a single LED. True MTBF is claimed/60.
That was their undoing. I expect you can still buy them on fleaBay.
--
Martin Brown
søndag den 10. september 2023 kl. 17.21.07 UTC+2 skrev Fred Bloggs:
On Sunday, September 10, 2023 at 11:10:59â¯AM UTC-4, Lasse Langwadt Christensen wrote:
søndag den 10. september 2023 kl. 16.44.38 UTC+2 skrev Fred Bloggs:
On Saturday, September 9, 2023 at 7:40:53â¯PM UTC-4, whit3rd wrote:
On Saturday, September 9, 2023 at 7:11:50â¯AM UTC-7, Fred Bloggs wrote:
On Saturday, September 9, 2023 at 9:01:28â¯AM UTC-4, Lasse Langwadt Christensen wrote:
lørdag den 9. september 2023 kl. 14.46.48 UTC+2 skrev Fred Bloggs:
Uh-huh. LEDs don\'t flicker. They\'re all powered by regulated switching ***current*** sources operating in the 20kHz-30kHz range. LEDs are not directly powered by voltage, and the current sources are immune to voltage fluctuation.
some are linear, enough LEDs in series to add up to most of the rectified line voltage
I\'m pretty sure they\'ve never used that method for the commodity lighting bulb market. Maybe for signs and indicator bulb types of applications where it has to be dirt cheap.
And consumer commodity bulbs don\'t have to be dirt cheap? These type lamps
https://www.ikea.com/us/en/p/solhetta-led-bulb-e26-450-lumen-globe-clear-10530117/
certainly are \'enough LEDs in series\' and not much else; there\'s no ROOM for more parts than that.
It\'s probably grade F efficiency:
it\'s grade C which in the pre 2020 rating would have been better than A++
That\'s not the Edison filament bulb. I didn\'t find one that he did on the Solhetta.
there is seval types of Solhetta bulbs
the filament one is (new) grade C
https://www.ikea.com/dk/da/p/solhetta-led-paere-e27-470-lumen-globe-klar-00498660/