100/120Hz light flicker regulations are not so "green"....not so energy efficient.?

With Greta Thunberg getting stronger politically, do you believe there will be a relaxation on 100Hz/120Hz light flicker laws? (EN12464)

For example, the most efficient way to power LEDs (at 200W) off the EU/UK mains, is with a BCM Boost PFC feeding a long series LED bank. However, like that, in order to get light flicker down to low enough levels, one needs at least 100uF of (450V+) capacitance across the LED bank. This is bound to be electrolytic capacitance, since at 100uF, films are just too expensive.

Electrolytics have life time issues, and so this is not a “green” solution, unless of course the light flicker laws can be softened, and then just a small film capacitor can suffice instead of the large electrolytic bank.

At 200W, off the mains, one can of course achieve low light flicker and use low amounts of capacitance…however, this needs two power stages….a PFC stage, followed by eg a Buck LED driver stage……..the Buck LED driver stage can then reject the high output ripple of the “lowly output capacitanced” PFC stage…however, two power stages in cascade means less efficiency…..so again Greta Thunberg “laws” are violated. So will Light flicker level regulations be softened?

Can you post a copy of the regulation?

Sorry, Unfortunately i dont have a copy. I think its a few hundred £'s.
This seems to hark to EN12464....

How flicker is perceived is very subjective, and some people are more sensitive than others.

I would have thought that the environmental impact of lighting comes mainly from the electricity used, so LED lighting will have far less impact than incandescent even if the life isn't as good as it could be.

There are other approaches than using electrolytics. Here is one:- https://www.ledsmagazine.com/leds-s...deliver-improved-flicker-performance-magazine

Flyback said:

Electrolytics have life time issues, and so this is not a “green” solution, unless of course the light flicker laws can be softened, and then just a small film capacitor can suffice instead of the large electrolytic bank.

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I don't see the problem?, as long as you use decent quality electrolytics they will last for decades, certainly outlasting the estimated service life of the fixture.

If you buy the cheapest crappiest ones you can find, with a design life under 12 months, obviously you're just asking for trouble.

If you buy the cheapest crappiest ones you can find, with a design life under 12 months, obviously you're just asking for trouble.

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Thanks yes, and there are no regulations in high power equipment for them to declare what spec of electrolytics they have used.
Also, as you would agree im sure, there are definetely a number of applications which mandate the NON use of electrolytic capacitors....due to their lifetime issues....and thats even the top quality electroytics.

"Lifetime issues" are down to the equipment designer!

Many common electrolytics are rated at eg. 3000 - 5000 hours life.
5000 hours is 208 days.
That is based on them being run at maximum ratings - voltage, temperature and ripple current etc.

The true lifetime relies on the designer of the equipment they are used in, using well under, or a fraction, of the max ratings.

eg. See the Cornell-Dubilier life calculator here:

Selecting 450V 120uF, at the maximum 1.6A 100Hz ripple, 40'C ambient and 450V, the expected life is 15200 hours (about two years).

Drop the ripple to 0.5A and at 350V, the life expectancy increases to over 240,000 hours (27 years)
Reduce the temperature to 30' and it jumps to near half a million hours; over 50 years.

Properly designed gear can last many decades, with appropriately specified electrolytics included!

Edit - meant to add this, their full guide including optimising lifetime:

In lighting, as well as most engineering, there are compromises.

In lighting, a few features that I can think of are safety, efficiency, item cost, longevity, power factor, colour rendering, evenness of illumination, flicker, ability to be dimmed, start up time and the ability to handle some leakage current without glowing or otherwise misbehaving.

Take your pick, but the best for one won't be the best for any the others. It's always been like that. Many years ago low pressure sodium lights were used for street lights. They were good on longevity and efficiency, but initial cost, colour rendering and start-up time were terrible, so they were never used for indoor applications*.

LEDs are vastly better than incandescent, and better than fluorescent, for efficiency. That doesn't immediately make them better for everything, and badly designed LED systems can have bad flicker (some VW tail lights are terrible for that). Improving any other feature will tend to make the efficiency worse, but from the worst LED flicker to the best doesn't mean a big fall in efficiency.

The OP mentioned PFC. That is surely adding cost and loss of efficiency to the design. PFC is all about not upsetting the mains supply. Lack of flicker is all about not upsetting the users. I may be only some people who are sensitive, but the PFC is only useful in some applications.

* Where I used to work we had a low pressure sodium light indoors because we wanted light that was dominated by a single wavelength, and we had to shade out the room light where we were using it.

Flyback said:

Thanks yes, and there are no regulations in high power equipment for them to declare what spec of electrolytics they have used.
Also, as you would agree im sure, there are definetely a number of applications which mandate the NON use of electrolytic capacitors....due to their lifetime issues....and thats even the top quality electroytics.

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In very rare cases perhaps, what is the design life of the lights? - it's hardly a concern for street lights etc. which will be replaced anyway after a certain number of years.