5 ms·
Well I don't know the frequency, but it is easily noticeable to me on most modern cars when moving my eyes. It's definitely not a question of aftermarket module
by seszett 4y ago
Well I don't know the frequency, but it is easily noticeable to me on most modern cars when moving my eyes. It's definitely not a question of aftermarket modules.
The PWM I use at home on an ESP32 is supposed to be in the 1-10 kHz range and I don't see flicker when moving my eyes.
- jeffbee 4y agoYeah, you'd be superman if you thought you could see a khz flicker. I associate flickering headlights with aftermarket because cars with halogen headlights use low-frequency PWM to regulate down high system voltages to 12V. So if you install aftermarket LED kits on those cars you are going to see a PWM of ~90Hz which is awful.
- p1mrx 4y ago> use low-frequency PWM to regulate down high system voltages to 12V That can't be right. Cars are primarily 12VDC.
- jeffbee 4y agoSystem voltage when the engine is running are higher otherwise the 12V battery would never charge. Can be as high as 18V. So cars with halogen lights with just chop it down to 12V. Here's a random video I found demonstrating the phenomenon. https://www.youtube.com/watch?v=82tFav8oGFI https://www.youtube.com/watch?v=82tFav8oGFI
- p1mrx 4y agoInteresting, so they're using PWM to hold the headlights at constant brightness when the alternator runs. Wiring a capacitor in parallel with the headlights should fix that.
- seszett 4y agoActually I forgot to mention that is it mostly the case for taillights (the most noticeable since you're going to follow cars quite often) and accent lights (like the vertical strips on the front of recent Peugeot cars). Not really on headlights I guess so I might be off-topic. And although I understand how some people can find it annoying, I don't really mind them. But I can definitely see the flicker and can compare the duty cycle between different cars.