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
Kill LED lamp flicker
Started by ●September 8, 2023
Reply by ●September 9, 20232023-09-09
Reply by ●September 9, 20232023-09-09
On Sat, 9 Sep 2023 05:46:43 -0700 (PDT), Fred Bloggs <bloggs.fredbloggs.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.
Reply by ●September 9, 20232023-09-09
On Sat, 9 Sep 2023 07:11:44 -0700 (PDT), Fred Bloggs <bloggs.fredbloggs.fred@gmail.com> wrote:>On Saturday, September 9, 2023 at 9:01:28?AM UTC-4, Lasse Langwadt Christensen wrote: >> l�rdag 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.
Reply by ●September 9, 20232023-09-09
On Sat, 9 Sep 2023 07:21:18 -0700 (PDT), Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:>l�rdag 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: >> > l�rdag 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=Qbkys3CHIaJnYFq9Does 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.
Reply by ●September 9, 20232023-09-09
lørdag den 9. september 2023 kl. 17.01.11 UTC+2 skrev John Larkin:> 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.https://youtu.be/nMc6mjE9Y1s?si=XBeDXe_ID2yXwxtG&t=735
Reply by ●September 9, 20232023-09-09
lørdag den 9. september 2023 kl. 16.55.02 UTC+2 skrev John Larkin:> 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: > >> lřrdag 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.the cap is usually down in the thread metal part
Reply by ●September 9, 20232023-09-09
On Fri, 8 Sep 2023 12:07:26 -0700 (PDT), Lasse Langwadt Christensen <langwadt@fonz.dk> wrote:>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 factorPhilips has an RCD string that develops near-unity power factor over a wide range - but still use a low-power LV rectifier / electrolytic to drive the string(s) (~36VDC). But they also have other types in the field . . . . RL
Reply by ●September 9, 20232023-09-09
On Saturday, September 9, 2023 at 10:50:33 AM UTC-4, John Larkin wrote:> 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.They should have borrowed the ultra cheap mass produced constant current switchers from the CFL days.
Reply by ●September 9, 20232023-09-09
On Saturday, September 9, 2023 at 10:55:02 AM UTC-4, John Larkin wrote:> 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: > >> lřrdag 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.They probably wanted that cheap and inefficient method to produce warmth, making the emulation more authentic.
Reply by ●September 9, 20232023-09-09
On Saturday, September 9, 2023 at 7:11:50 AM UTC-7, Fred Bloggs wrote:> 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:> > > 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.
