Isn't this article conflating PWM flicker with cheap AC rectifiers causing LEDs to flicker because they periodically, at 50 Hz, get under the voltage they need to emit any light? I can't see why light fixtures in buildings—except modern ones where the lights are actually dimmable—would even have any sort of PWM.
Yes it absolutely is. Those are candle-style bulbs that use filament LEDs, they’re normally just use a basic rectifier and a regulator chip that does basic linear regulation of the peak of the sine wave.
They flicker at 100Hz due to the rectification (or 120hz in those 60hz countries of course).
There is a pendant light in my entryway that came outfitted with LED filament bulbs when I bought my home. They flicker noticeably, and I would have replaced them all if it were in my living room.
One of the bulbs recently burned out, and I picked up a replacement at Menards. Even though it was just a basic Sylvania, the new one clearly has a rectifier circuit as it does not exhibit any flickering that I can detect.
So anecdotally at least, the cheap bulbs without rectifiers seem to be going away from the big box stores (although I’m sure you can still get them with unpronounceable all-caps names from Amazon).
> I can't see why light fixtures in buildings—except modern ones where the lights are actually dimmable—would even have any sort of PWM.
It is done because, like most crappy things in the world, it saves somebody, somewhere, a few cents on the dollar.
Most people would not be able to tell the CRI impact of DC dimming vs PWM. Many do not visibly notice the difference. (I unfortunately do, and you won’t believe how many expensive Mercedes and similar cars flicker).
But high frequency PWM is slightly more difficult and expensive, and DC dimming might need a few more capacitors or inductors… so let’s save a buck there, shall we?
