What PWM frequency is sufficient to not notice flicker?

Question

Arduino

I plan to solve a standard task for an arduino - home lighting control. But the PWM frequency at the control inputs is confusing, it is on Leonardo from about 500 Hz to 1000 Hz. Is this frequency enough to keep the eyes from flickering when the LED strip is running at half brightness (and it rarely needs more)? I read on the internet about unique people who notice a flicker of 100 Hz on the monitor. I would not want to get unpleasant effects from the lighting in the apartment ...

Answer 1

As an option, read about increasing the PWM frequency by changing the data in the timer register, for the Arduino Uno, for example, it looks like this:
PWM frequency on legs 5 and 6:
Code:
Constant Divider Frequency (Hz)
0x01 1 62500 Hz
0x02 8 7812 Hz
0x03 64 976 Hz
0x04 256 244 Hz
0x05 1024 61 Hz
In Setup we write the line: TCCR0B = TCCR0B & 0b11111000 | <Constant>;
PWM frequency on legs 9 and 10:
Code:
Constant Divider Frequency (Hz)
0x01 1 31250 Hz
0x02 8 3906 Hz
0x03 64 488 Hz
0x04 256 122 Hz
0x05 1024 30 Hz
In Setup we write the line: TCCR1B = TCCR1B & 0b11111000 | <Constant>;
IMHO it's better to dig and make a larger frequency, in the region of 1-4 kHz. This is guaranteed not to be visible to the eye, while the frequency is relatively small for the key.

Answer 2

the eye will not notice the flicker already at 30Hz, but the brain will still be.
1000Hz is more than enough
If you are going to control the brightness of the lighting in your apartment, you need to know the following.
1. AC control requires taking into account the voltage transition through 0 to control the triac (it only turns off in this way), i.e. whether you like it or not, whether you see 100Hz flicker or not, it doesn't matter, because this is the only possible PWM frequency.
2. You can control lighting with PWM only using Ilyich bulbs, LDS (housekeeper) and LED (light-emitting diode) lamps. PWM will kill

Answer 3

There is no clear answer to this question, as the criteria are blurred. When cinema was invented, it was decided to consider 16 frames per second sufficient for a continuous perception of the picture. Then it seemed a little - they raised it to 24. Again a little - they installed a shutter, thanks to which each frame flashes twice - 48 (50) frames per second. This was also not enough for some unique ones - and for their pleasure, 100-Hz TVs appeared at the suggestion of marketers.
In fact, the inertia of the eyes has long been measured, it is recognized as sufficient to have flickers faster than 60 ... 85 hertz, so that they are guaranteed not to be noticed, so your 500 ...

Answer 4

I'll raise the topic. I have PWM control (ESP8266). Is it really possible to make it so that there are no ripples at all? That is, for PWM to control some device (driver), and it varied the (analog) DC voltage from 0 to 12V? What are the circuits or devices?

Answer 5

For illumination, even 100Hz is a low frequency and the eye sees it perfectly. This should not be confused with the frame rate in a video, where there is not a dark-light-dark switch, but a series of just pictures with approximately the same brightness, but moving details.
To understand that the eye will be uncomfortable, you need to conduct a "pencil test". Shake the pencil with your hand and determine if you see a blurry pencil or multiple pencils.
Usually 500Hz and above is normal. Optimal is about 1-5 kHz, then the eye no longer sees the difference, but there is still no load on the keys and LEDs due to switching.