New ideas for dimming method for the LED Bulb

[Zero999]

Or from customers who see no need to re-wire their dining room to replace the existing bulbs.

It shouldn't be that difficult to design a dimmable LED luminaire, which can be retrofitted to use standard UK wiring.

The UK ceiling rose is wired like this.


It wouldn't be hard to replace it with a different type of junction box, which permanently powers the lamp, with the switch going to an ADC input and pull-up current source. The switch could be replaced with a variable resistor, if dimming is required, or just left as is, if the dim function isn't used. The lamp would obviously need to have a very low standby power consumption: <1VA to be considered environmentally friendly.

The only issue might be complying with the wiring regulations and as I don't have an up to date copy, I don't know if it would be allowed.

[Marco]

Or from customers who see no need to re-wire their dining room to replace the existing bulbs.

Calling swapping out a dimmer rewiring is a bit exaggerated.

[RJSV]

Here is a second photo, of the drugstore 'garden light' that starts internal timer when batteries are installed.
   I bought at a local WALGREENS (no affiliations).
I had been impressed at the clever angle taken, as this outdoor lamp has no interface. But it starts tracking time, internally, with assumption that consumer had done the install, just at dusk, and so the little device assumes, on its own, that it was '6 O'Clock PM'.
   Put that concept in with the rest of the good ideas here and you now have 'TIME'.
  It's maybe not pretty... (How light bulbs are made).
...like the old joke about gross 'sausage making' factory.
   Using this method, might involve PATENT law...
a subject I'm very sensitive about, being an Inventor/Engineer.
By the way, I have not seen this 'self-timed Candlelebra' on sale for a couple of years.
Drug Stores often carry some interesting TOYS to check out, as an ever-curious Inventor.
- Rick B.

[TimNJ]

2. One feature I wish my light bulbs could have (without buying a $50 USD Philips Hue) is to automatically shift the color temperature to match the time of day. I use "f.lux" on my PC and I can tune the average color temperature of my monitor at different times of the day. I know scientific research has shown it's best to stay away from blue colored light late at night. For example, I would change all my bulbs in my bedroom and office room to this type if they were not so expensive like Philips Hue. I could probably justify spending $15 USD/bulb for this feature.

The technical hurdles are challenging (to do inexpensively)...How will the bulb know where it is on the planet? How does it know what time it is? A few quick thoughts: It could have some sort of NFC, IR, or some other crude communication interface interface which could program its location and time/date once...but then you need a RTC in the bulb, and I think that's probably a bad idea since I would not suggest putting a battery inside a blazing hot lightbulb. Another idea is to use powerline communication and some centralized hub that plugs into an outlet in your house. But then you need some magnetics and other bulky components to sense that signal. Finally, I wondered if you could use the atomic clock signal that many countries have, i.e. US in Texas (I think) and I think there are a few in China too. But that's never going to be so reliable, and you probably still need to have an RTC + battery.

Honestly, the cheapest/simplest solution to getting communication to a bulb is probably....WiFi or Bluetooth, especially given the low cost nRF chipsets that exist now, as much as I wish that wasn't true.

So, really I've got no good ideas on that, but I do wish that I could just screw in a light bulb and it would automatically change the color temperature perfectly, to match the time and my location. But, I think it's not so simple!

Hi, Tim:
I've discussed this idea with my colleagues, this is a brand new idea for bulb.
But also the most difficulty is how to tell the bulb the time.
1. RTC need an extra power supply...
2. Use low frequency radio to sense the time, the feed back is signal weak after setup in the building...
3. As you mentioned, receive from GNSS satellite , but the receiver/decoder size and cost cannot accept...
We'll continue discuss this topic.

I wouldn't worry about having an RTC, or sensing the time.  People generally don't need a bright, low colour temperature, or dim high colour temperature light. Which is why I suggested dim to warm, i.e. reducing the colour temperature, along with the light output, to mimick natural light sources such as the sun.

I agree with this approach, but how does the bulb have any concept of knowing what time it is in the first place?

I like Jon Paul's idea..

It sounds a little bit like the "pre-flash" for an automatic camera flash. i.e. the little stutter flash that happens a few 10's of milliseconds before the full power flash is applied during the exposure. The pre-flash is a constant lumen flash that bounces off the subject and back into the light sensor onboard the flash. The quantity of light detected by the sensor allows the camera to pick the proper flash setting for proper exposure.

For these flashes, the light sensor needs to be positioned such that it is not fooled by the light coming from the flash itself. So usually, the flash bulb is at least a 10-15mm in front of the sensor. See Minolta Auto 200X flash attached. Anyway, just rambling, kind of irrelevant to this discussion.

Perhaps the opposite could be adopted for this lightbulb. Every 15 minutes (or so), the bulb shuts off for a very short amount of time. During this off-time, the ambient light is detected. The wavelength and intensity shows whether it is day-time or nighttime. If using a microcontroller, perhaps a primitive machine-learning/neural network algorithm can be implemented which adjusts parameters based on each specific installation. The constants are stored in non-volatile memory. This may make it more flexible. Maybe unnecessary.

I am sure with enough research, it could be done fairly reliably. In the case where the logic is unsure of the time of the day, perhaps it can have a default state, i.e. 3500K @ 800lm.

[james_s]

2. One feature I wish my light bulbs could have (without buying a $50 USD Philips Hue) is to automatically shift the color temperature to match the time of day. I use "f.lux" on my PC and I can tune the average color temperature of my monitor at different times of the day. I know scientific research has shown it's best to stay away from blue colored light late at night. For example, I would change all my bulbs in my bedroom and office room to this type if they were not so expensive like Philips Hue. I could probably justify spending $15 USD/bulb for this feature.

There is more than one Philips Hue. The "white and color ambiance" bulbs are RGB/CCT and cost close to $50 retail but they also make a "white ambiance" series that is white only but variable CCT from 2200k-6500k and those are only $20-$25. If you want even cheaper, Ikea has their Tradfri line which includes several different types of variable CCT lamps using Zigbee. They even offer a wireless remote so you can control a lamp directly without needing any kind of hub. Even cheaper than that, Home Depot's Ecosmart brand has a variable CCT lamp that does 2700k-6500k $9.99 for a 2-pack, I have a few and they work fine, although I prefer the Hue as it has a much wider CCT range and can be programmed to store its last state if power is lost.

[james_s]

Or from customers who see no need to re-wire their dining room to replace the existing bulbs.

Calling swapping out a dimmer rewiring is a bit exaggerated.

It may as well be for the average person. Most of us here are technical people, we would not hesitate to swap out a switch in our home and could do it properly and safely. For the average non-technical person though swapping out a switch (safely at least) means hiring an electrician or handyman and that's a significant hassle and expense.

I don't know about the rest of the world outside of the UK but in the US there is no standard for the way switches are wired to lights. Sometimes you'll see the arrangement that seems to be standard in the UK where power comes directly into the light box and a separate switch drop runs from there to the switch. Other times power comes into the switch box and from there heads up to the light. Sometimes you see more complex situations where a single box contains two or more switches that control different lights, some fed from different circuits, some may be wired with power going straight to the light, others with power going straight to the box, some may be a middle "4-way" switch between a pair of 3-way switches, say on the entry landing of a split level house like mine. As I've discovered with my automation efforts, sometimes trying to do a non-wireless approach does require doing some significant rewiring.

[Zero999]

2. One feature I wish my light bulbs could have (without buying a $50 USD Philips Hue) is to automatically shift the color temperature to match the time of day. I use "f.lux" on my PC and I can tune the average color temperature of my monitor at different times of the day. I know scientific research has shown it's best to stay away from blue colored light late at night. For example, I would change all my bulbs in my bedroom and office room to this type if they were not so expensive like Philips Hue. I could probably justify spending $15 USD/bulb for this feature.

The technical hurdles are challenging (to do inexpensively)...How will the bulb know where it is on the planet? How does it know what time it is? A few quick thoughts: It could have some sort of NFC, IR, or some other crude communication interface interface which could program its location and time/date once...but then you need a RTC in the bulb, and I think that's probably a bad idea since I would not suggest putting a battery inside a blazing hot lightbulb. Another idea is to use powerline communication and some centralized hub that plugs into an outlet in your house. But then you need some magnetics and other bulky components to sense that signal. Finally, I wondered if you could use the atomic clock signal that many countries have, i.e. US in Texas (I think) and I think there are a few in China too. But that's never going to be so reliable, and you probably still need to have an RTC + battery.

Honestly, the cheapest/simplest solution to getting communication to a bulb is probably....WiFi or Bluetooth, especially given the low cost nRF chipsets that exist now, as much as I wish that wasn't true.

So, really I've got no good ideas on that, but I do wish that I could just screw in a light bulb and it would automatically change the color temperature perfectly, to match the time and my location. But, I think it's not so simple!

Hi, Tim:
I've discussed this idea with my colleagues, this is a brand new idea for bulb.
But also the most difficulty is how to tell the bulb the time.
1. RTC need an extra power supply...
2. Use low frequency radio to sense the time, the feed back is signal weak after setup in the building...
3. As you mentioned, receive from GNSS satellite , but the receiver/decoder size and cost cannot accept...
We'll continue discuss this topic.

I wouldn't worry about having an RTC, or sensing the time.  People generally don't need a bright, low colour temperature, or dim high colour temperature light. Which is why I suggested dim to warm, i.e. reducing the colour temperature, along with the light output, to mimick natural light sources such as the sun.

I agree with this approach, but how does the bulb have any concept of knowing what time it is in the first place?

It doesn't need to know. The user sets the brightness and the colour temperature is automatically adjusted. I don't want any fancy AI in a light bulb, even though it would be fun to design.

[TimNJ]

2. One feature I wish my light bulbs could have (without buying a $50 USD Philips Hue) is to automatically shift the color temperature to match the time of day. I use "f.lux" on my PC and I can tune the average color temperature of my monitor at different times of the day. I know scientific research has shown it's best to stay away from blue colored light late at night. For example, I would change all my bulbs in my bedroom and office room to this type if they were not so expensive like Philips Hue. I could probably justify spending $15 USD/bulb for this feature.

The technical hurdles are challenging (to do inexpensively)...How will the bulb know where it is on the planet? How does it know what time it is? A few quick thoughts: It could have some sort of NFC, IR, or some other crude communication interface interface which could program its location and time/date once...but then you need a RTC in the bulb, and I think that's probably a bad idea since I would not suggest putting a battery inside a blazing hot lightbulb. Another idea is to use powerline communication and some centralized hub that plugs into an outlet in your house. But then you need some magnetics and other bulky components to sense that signal. Finally, I wondered if you could use the atomic clock signal that many countries have, i.e. US in Texas (I think) and I think there are a few in China too. But that's never going to be so reliable, and you probably still need to have an RTC + battery.

Honestly, the cheapest/simplest solution to getting communication to a bulb is probably....WiFi or Bluetooth, especially given the low cost nRF chipsets that exist now, as much as I wish that wasn't true.

So, really I've got no good ideas on that, but I do wish that I could just screw in a light bulb and it would automatically change the color temperature perfectly, to match the time and my location. But, I think it's not so simple!

Hi, Tim:
I've discussed this idea with my colleagues, this is a brand new idea for bulb.
But also the most difficulty is how to tell the bulb the time.
1. RTC need an extra power supply...
2. Use low frequency radio to sense the time, the feed back is signal weak after setup in the building...
3. As you mentioned, receive from GNSS satellite , but the receiver/decoder size and cost cannot accept...
We'll continue discuss this topic.

I wouldn't worry about having an RTC, or sensing the time.  People generally don't need a bright, low colour temperature, or dim high colour temperature light. Which is why I suggested dim to warm, i.e. reducing the colour temperature, along with the light output, to mimick natural light sources such as the sun.

I agree with this approach, but how does the bulb have any concept of knowing what time it is in the first place?

It doesn't need to know. The user sets the brightness and the colour temperature is automatically adjusted. I don't want any fancy AI in a light bulb, even though it would be fun to design.

Are you talking about a bulb which automatically changes color temperature as it is manually dimmed from a wall-plate dimmer? Interestingly enough, many LEDs do this "naturally" already, i.e. at lower forward current, the color temperature goes down, but usually the shift is probably not much more than 500-750K, IIRC.

I am talking about a bulb which after installation, automatically dims and/or changes color temperature in accordance with the time of day. i.e. At noon, 5000K, at dusk 3500K, at night 2200K, etc. I don't want any human intervention, no programming, no opening an app. So, the bulb itself needs some intelligence to determine when it is day and when it is night.

As Jon Paul suggested, and may very well already exist(!), the bulb can have a light sensor (or two). The bulb can be shut off for a short amount of time, un-noticeably and periodically throughout the day, to make this ambient measurement. I think no need to be scared of 'AI' in this context. The learning algorithm I'm suggesting can probably be run on an 8051, since it will have 10's of minutes to process the data . Basically, depending on the environment, room X's night-time may look different than room Y's night-time. (i.e. In a city, perhaps a streetlight shines in the window at night, but on a farm there is total darkness.) Hard pre-programmed thresholds may give...unexpected results.

Maybe I'm talking out my ass, I don't know. I kinda want to try now though!

[james_s]

It doesn't need to know. The user sets the brightness and the colour temperature is automatically adjusted. I don't want any fancy AI in a light bulb, even though it would be fun to design.

Those have existed for years, the Philips 'Warm Glow' series. I have a handful of them I bought probably 5 years ago.

https://www.usa.lighting.philips.com/consumer/choose-a-bulb/warm-glow-dimmable-led-lighting

[CatalinaWOW]

Just a thought here.  I am an older guy, but like the wifi control features in lamps and use them regularly.  One of the uses is to simulate habitation when I am away from home for a while.  Most of the bulbs I have used have a "reliability" problem.  If there is a brief power failure, or some types of glitches these bulbs come back on line in what seems to be a totally random state.  Sometimes in the "program" mode.  Sometimes in a flashing "fault" mode.  Sometimes off and uncommunicative.  This is not unique to bulbs.  Many "smart" devices have these kinds of issues.

I would really like a bulb that had a consistent behavior in the presence of unstable power.  Preferably returning to the previous state.  I know there are many issues with this, but that is what makes it an engineering problem worthy of attack.

[james_s]

A serious flaw with most "smart" bulbs is that they default to full brightness white light, so if you have a bunch of them around the house and you get a momentary power glitch, a common occurrence around here in the winter, all the lights come on full brightness. Lots of fun when it happens in the middle of the night as is often the case for storms. After the most recent firmware update the Philips Hue lamps let you configure the default state which is fantastic, I really don't know why others don't. Having it remain in the last used state unless you do something clearly deliberate like flip the light on and off 3 times in succession seems like the obvious thing to have it do.

I have several different brands of zigbee bulbs in service but I'm not using any of the hubs, I just have a Conbee II stick plugged into my Raspberry Pi based Home Assistant server. It's a bit of work to set it up but once that's done it works the way all this smart home stuff ought to work, everything interoperates with everything else and cloud is totally optional.

[Zero999]

2. One feature I wish my light bulbs could have (without buying a $50 USD Philips Hue) is to automatically shift the color temperature to match the time of day. I use "f.lux" on my PC and I can tune the average color temperature of my monitor at different times of the day. I know scientific research has shown it's best to stay away from blue colored light late at night. For example, I would change all my bulbs in my bedroom and office room to this type if they were not so expensive like Philips Hue. I could probably justify spending $15 USD/bulb for this feature.

The technical hurdles are challenging (to do inexpensively)...How will the bulb know where it is on the planet? How does it know what time it is? A few quick thoughts: It could have some sort of NFC, IR, or some other crude communication interface interface which could program its location and time/date once...but then you need a RTC in the bulb, and I think that's probably a bad idea since I would not suggest putting a battery inside a blazing hot lightbulb. Another idea is to use powerline communication and some centralized hub that plugs into an outlet in your house. But then you need some magnetics and other bulky components to sense that signal. Finally, I wondered if you could use the atomic clock signal that many countries have, i.e. US in Texas (I think) and I think there are a few in China too. But that's never going to be so reliable, and you probably still need to have an RTC + battery.

Honestly, the cheapest/simplest solution to getting communication to a bulb is probably....WiFi or Bluetooth, especially given the low cost nRF chipsets that exist now, as much as I wish that wasn't true.

So, really I've got no good ideas on that, but I do wish that I could just screw in a light bulb and it would automatically change the color temperature perfectly, to match the time and my location. But, I think it's not so simple!

Hi, Tim:
I've discussed this idea with my colleagues, this is a brand new idea for bulb.
But also the most difficulty is how to tell the bulb the time.
1. RTC need an extra power supply...
2. Use low frequency radio to sense the time, the feed back is signal weak after setup in the building...
3. As you mentioned, receive from GNSS satellite , but the receiver/decoder size and cost cannot accept...
We'll continue discuss this topic.

I wouldn't worry about having an RTC, or sensing the time.  People generally don't need a bright, low colour temperature, or dim high colour temperature light. Which is why I suggested dim to warm, i.e. reducing the colour temperature, along with the light output, to mimick natural light sources such as the sun.

I agree with this approach, but how does the bulb have any concept of knowing what time it is in the first place?

It doesn't need to know. The user sets the brightness and the colour temperature is automatically adjusted. I don't want any fancy AI in a light bulb, even though it would be fun to design.

Are you talking about a bulb which automatically changes color temperature as it is manually dimmed from a wall-plate dimmer?

Yes.

Interestingly enough, many LEDs do this "naturally" already, i.e. at lower forward current, the color temperature goes down, but usually the shift is probably not much more than 500-750K, IIRC.

I can't say I've noticed. It's easy to get a larger colour temperature shift by haing arrays of different colour temperature LEDs.

I am talking about a bulb which after installation, automatically dims and/or changes color temperature in accordance with the time of day. i.e. At noon, 5000K, at dusk 3500K, at night 2200K, etc. I don't want any human intervention, no programming, no opening an app. So, the bulb itself needs some intelligence to determine when it is day and when it is night.

As Jon Paul suggested, and may very well already exist(!), the bulb can have a light sensor (or two). The bulb can be shut off for a short amount of time, un-noticeably and periodically throughout the day, to make this ambient measurement. I think no need to be scared of 'AI' in this context. The learning algorithm I'm suggesting can probably be run on an 8051, since it will have 10's of minutes to process the data . Basically, depending on the environment, room X's night-time may look different than room Y's night-time. (i.e. In a city, perhaps a streetlight shines in the window at night, but on a farm there is total darkness.) Hard pre-programmed thresholds may give...unexpected results.

Maybe I'm talking out my ass, I don't know. I kinda want to try now though!

No doubt it's possible and would certainly be a fun project, but it isn't something I'd be interested in installing in my house. There's too much scope for it to go wrong. I'd rather have a simple, dumb manual control.

[TimNJ]

No doubt it's possible and would certainly be a fun project, but it isn't something I'd be interested in installing in my house. There's too much scope for it to go wrong. I'd rather have a simple, dumb manual control.

I agree that there are likely many many corner cases that could easily fool such a design. Given that the world seems to be going towards 'connected' everything anyway, trying to solve this issue in a non-connected way probably is for naught. I still like the idea of plugging something in and not having to touch it though.

[TimFox]

There’s a difference between installing a novel system and replacing a bulb.  “Replacing a light bulb” used to signify a simple process.

[jonpaul]

Rebonjiur, the post is confusing as the objective seems to be a LED "light bulb" rather than a fixure or luminarie.

The screw in bulbs are now obselescent in exishtng homes and fixtures.

Best efficiency is replacing the fixture.

Scre in bulbs have very limited size, base etc.

The OP should exactly define what he wants:

A screw in bulb replacement?

A controllable and highly efficient light fixture?

Seem most of the thread is fixed on screw in bulbs.

Jon

[TimFox]

Edison-base bulbs have been around for a while.  Staying with a standard interface as the technology advances to new forms of light can be a sensible strategy for domestic purposes, rather than forcing consumers to change sockets when not truly necessary.

[KalyanProdhan]

Hi,

I am an Govt. engineer, and philips was (not is) our first choice. But in India, after taken over by signify, the quality was drastically going down. The 20 watt slim recessed lights installed in the very important seminar halls, meeting rooms, and in youth hostels are get blinked when any switching in the ceiling fan or even regulator function happens.

While going through the driver circuit, I found absence of several parts in PCB. In this case, the filtering large capacitor, just after the rectifier, is absent, don't know, why, (causing reset of IC due to micro power surge)? Several times I found common mode chokes are replaced with single side drum inductor. Many times, the biasing resistances and electrolytic capacitors remain absent, reducing the life of the entire luminaire drastically.
In retrofit T8 lamps, the two series resistance used in series of line & neutral, are of low wattage, and fails mostly. And in street light and high wattage lights, surge units are mostly compromised. I can send you the pictures of the failures, in lot, it's reason, reverse engineered. Later, insted of replacing a lot of fittings, we have to install separate surge unit, to use those fittings.

An interesting fault was found that due to replacement of rubber gasket, with plastic gasket. The metal body enlarged in heat, but the optics are get cracked, as it was get stress, due to absence of rubber cushion in between screw and optics hole.

In India at present, general publics are not want to pay more for philips, while they get failure even quicker than their local brand. Even us, the govt. officials, having the maximum inertia of thinking (As we cannot experiment more with public money), are changing.

Sometime some rumers came in ear that great quantity was manufactured in india by it's dealers in their private workshop, to cope up with high surge of demand before Puja and March year ending. Surprisingly after inspection, when query is done from govt. officials or it's vendor, philips signify says it's their product, and then repair or replace later. I have the official documents, but cannot upload here without permission.

If this is the quality of the our old beloved philips, sorry to say, PHILIPS dying...

If you really want to know the differance of your design, and what we get in reality, you should purchase philipsproduct, from that country's store (may be online store), and test the differance.

An visit to youth hostel in purulia, west bengal, I captured the video of blinking of philips light, with ceiling fan regulator changing.
Here is the link. The language is in local language bengali, however, you will realise, the current status of your reputed brand in INDIA.

https://youtu.be/8EwshMsoBkc

[james_s]

Edison-base bulbs have been around for a while.  Staying with a standard interface as the technology advances to new forms of light can be a sensible strategy for domestic purposes, rather than forcing consumers to change sockets when not truly necessary.

Totally agree. I have mostly vintage fixtures in my 1970s house, I like them and modern ones would look totally wrong. Also having a reputation as a handy guy, I am frequently called over by family and friends to fix things and on several occasions I have had to replace integrated LED light fixtures that had failed. Even the most technologically inept person can change a light bulb, most people have to call an electrician or handyman to change a fixture. Initially creating a good screw-in LED lamp was a significant technological hurdle but now that problem is solved. The only reason there are so many low quality bulbs out there is that consumers are highly sensitive to price. If you buy the cheapest product you can find, whether a screw-in bulb or integrated fixture, it is likely to not last long. Integrated LEDs offer possibilities of entirely new fixture designs that were not possible with old fashioned light bulbs but for traditional styles screw-in retrofit lamps are arguably the best option, they are available in a plethora of varieties from basic 99c bulbs to expensive RGBW smart bulbs in a multitude of shapes and styles that all fit into a standard and ubiquitous socket.

[themadhippy]

but for traditional styles screw-in retrofit lamps are arguably the best option

unless your in the uk,  were the bayonet cap is more commonly found

[TimFox]

Of course.  As Edmund Burke did not say, conservatively, "If it is not necessary to change, then it is necessary not to change."  Pedants can look for the actual quotation by Lucius Cary, 2nd Viscount Falkland in a speech in the House of Commons on Nov. 22, 1641.

Source: https://quotepark.com/quotes/1852601-edmund-burke-if-it-is-not-necessary-to-change-it-is-necessary/

[SiliconWizard]

Edison-base bulbs have been around for a while.  Staying with a standard interface as the technology advances to new forms of light can be a sensible strategy for domestic purposes, rather than forcing consumers to change sockets when not truly necessary.

Indeed. I haven't read the whole thread so sorry if it has been brought up already: I was thinking that a way to implement more "intelligent" bulbs while keeping the same sockets and same electric installation would be to use PLC. Thus you could transfer both power and data using an unmodified installation.

[TimFox]

That's an intermediate case among the following choices.
1.  Screwing a new light-bulby object into an existing socket powered with 120 VAC from a "conventional" wall switch or dimmer.
2.  Having the new smart bulb contain WiFi control, or wireless LAN through the line, from an external controller, taking power from the existing socket.
3.  Changing the wall switch and possibly the socket to use a more complicated interface, possibly with different power feed, to the new bulb.
Personally, I think the better business plan to sell new bulbs to consumers does not require changing the socket and wiring, so (1) or (2) are reasonable.

[Marco]

It seems to me the main problem of making LED lamps compatible with dimmers is cheaping out on the electronics. A simplistic capacitive or resistive dropper obviously will not work well with Triacs, but there's no reason an active two stage DC-DC can't always and immediately pull enough current to keep the Triacs on and use the phase angle for dimming.

It's more a question of marketing LED bulbs for compatibility with all dimmers and convincing consumers they should pay a premium. All the complexity of PFC, but still a lousy PF.

[jonpaul]

Marco the issue of LED compatible to existing dimmers is very well researched and solved.

Capacitive or resistive droppers are not used, and most ballasts are either triac compatible or not ("dimmable")

There are 100s (or 1000s) of patents and papers in the area.

Design Tradeoffs are in efficiency, PFC and compatibility.

I think the OP wanted input on controls rather than ballast topology.

Jon

[Marco]

It's well researched, but it's not well marketed.

Triac dimmer compatible non flickering LED light, tell me where? You're not going to get there without a two stage (or two path) DC-DC converter and who has the margins or the desire to put that in a bulb? Preferably build with film capacitors instead of electrolytic.

Everything is lowest common denominator trash. Maybe Apple should start making LED bulbs?