LEDs aren’t 50Hz or 60Hz or anything else. They’re DC devices and they don’t flicker at all if you run them on a clean DC power supply.
The issue with LED bulbs is that they don’t have clean power supplies. They have very simple AC to DC, usually a capacitive dropper. Without filtering, this type of cheap power supply produces a lot of ripple which manifests in visible flicker at the same frequency of the input AC mains power.
Yup. Except they flicker at double the mains frequency because they use both the positive and negative half-cycle thanks to a FULL BRIDGE RECTIFIER.
And see my other comment: it’s not unhealthy, just annoying. To be honest, I use trash-picked LED bulbs and repair them, and I don’t normally care to replace a poor smoothing capacitor. In rooms I spend much of my time, I make sure most bulbs in the fixture are low-flicker (it’s arbitrary but generally don’t get below 75%) for comfort. I’m not peculiar about light quality like CRI and matching color temperature unless it’s very obviously bad, although I do notice the circadian effects of cold white light. I do mark badly flickering bulbs though so I know not to put too many of them together unless it’s somewhere non-consequential like a cellar. I also hold my phone camera to any neutral-white E27s I salvage to find and mark true flicker-free ones because I use them while filming.
That just means the driver is not flicker free, not the LED board itself, and there are flicker free drivers out there but they’re just not available for the average consumer.
But visible flicker? On an LED that’s just emitting light? I’ve never seen that before. Maybe it’s a UK and Europe thing.
I live in Canada (60Hz here) and I just installed a new range hood above my stove. It came with standard recessed halogen light fixtures with LED bulbs. Rather than being fully dimmable, the switch has high and low settings. When set to low, I can definitely see visible flicker.
I also have this same style of lights above my bathroom mirror and a dimmer switch there. They also display more and more flicker when dimmed.
Ah. That’s a driver issue again. The dimmer is adjusting the voltage, and it the voltage dips too low, the LED chips don’t have enough juice to run. Hence the flickering. If there is a driver attached to your LEDs, you might want to consider a 0-10V driver or one that specifically says flicker free.
EldoLED drivers are excellent for this but costly because they’re commercial grade.
Ah connected to mains. There would be a way to add a driver in between but will require an electrician and it’s just not worth it if you can just put it to high output.
50Hz is what you’ll find in the UK and Europe.
LEDs aren’t 50Hz or 60Hz or anything else. They’re DC devices and they don’t flicker at all if you run them on a clean DC power supply.
The issue with LED bulbs is that they don’t have clean power supplies. They have very simple AC to DC, usually a capacitive dropper. Without filtering, this type of cheap power supply produces a lot of ripple which manifests in visible flicker at the same frequency of the input AC mains power.
Yup. Except they flicker at double the mains frequency because they use both the positive and negative half-cycle thanks to a FULL BRIDGE RECTIFIER.
And see my other comment: it’s not unhealthy, just annoying. To be honest, I use trash-picked LED bulbs and repair them, and I don’t normally care to replace a poor smoothing capacitor. In rooms I spend much of my time, I make sure most bulbs in the fixture are low-flicker (it’s arbitrary but generally don’t get below 75%) for comfort. I’m not peculiar about light quality like CRI and matching color temperature unless it’s very obviously bad, although I do notice the circadian effects of cold white light. I do mark badly flickering bulbs though so I know not to put too many of them together unless it’s somewhere non-consequential like a cellar. I also hold my phone camera to any neutral-white E27s I salvage to find and mark true flicker-free ones because I use them while filming.
That just means the driver is not flicker free, not the LED board itself, and there are flicker free drivers out there but they’re just not available for the average consumer.
But visible flicker? On an LED that’s just emitting light? I’ve never seen that before. Maybe it’s a UK and Europe thing.
I live in Canada (60Hz here) and I just installed a new range hood above my stove. It came with standard recessed halogen light fixtures with LED bulbs. Rather than being fully dimmable, the switch has high and low settings. When set to low, I can definitely see visible flicker.
I also have this same style of lights above my bathroom mirror and a dimmer switch there. They also display more and more flicker when dimmed.
Ah. That’s a driver issue again. The dimmer is adjusting the voltage, and it the voltage dips too low, the LED chips don’t have enough juice to run. Hence the flickering. If there is a driver attached to your LEDs, you might want to consider a 0-10V driver or one that specifically says flicker free.
EldoLED drivers are excellent for this but costly because they’re commercial grade.
There’s no driver. These are bulbs designed for traditional halogen fixtures which connect directly to 120V mains AC.
Ah connected to mains. There would be a way to add a driver in between but will require an electrician and it’s just not worth it if you can just put it to high output.
Electrician? I do my own electrical work! This issue is pretty low priority for me though. I have a ton of other things to fix around the house!