Frequency Control of Fan PWM

[nkonidaris]

Checklist

• [X] I have filled out the template to the best of my ability.
• [X] This only contains 1 feature request (if you have multiple feature requests, open one feature request for each feature request).
• [X] This issue is not a duplicate feature request of previous feature requests.

Is your feature request related to a problem? Please describe.

Running the RPI PWM fun as slow speed with a low frequency produces quite a bit of noise.

Describe the solution you'd like

Could you please include the ability to change the PWM frequency for the Fan entity.

Describe alternatives you've considered

Where I can set the frequency in the python script to create my own integration.

Additional context

Home Assistant gives an error when trying to use the Frequnecy: tag when using a Fan.

[RedMeKool]

Hi, you can already use fan.set_percentage service to control the speed of the fan and make your own fan control automation. Or is this not what you require?

[nkonidaris]

Hi, you can already use fan.set_percentage service to control the speed of the fan and make your own fan control automation. Or is this not what you require?

Good day, @RedMeKool

Thanks for your quick response. Perhaps I explained badly, I want to change the PWM Frequency for a given duty cycle. I believe changing the fan speed (set_percentage) will change the PWM duty cycle. However, if the PWM frequency is too low and the duty cycle (fan speed / percentage) is low then it hum's with an annoying tone.

Thanks Nick

[casse-boubou]

Hi! Sorry I don't see frequency property in the Doc :/ https://developers.home-assistant.io/docs/core/entity/fan/

[nielsnl68]

I would like to have this as well 👍🏼

[thomasbarton]

I would like this feature as well.

I think what the author means is that PWMOutputDevice supports an optional parameter of frequency. This option is needed because if the frequency of the PWMOutputDevice is mismatched with the device it is controlling it can cause the device to behave in unexpected or annoying ways. It seems like lots of computer PWM fans are operating on a 25,000Hz frequency. The default frequency of PWMOutputDevice is 100Hz.

I have noticed that when PWMOutput device frequency is not matched with the fans expected frequency that the fan will make extra noise, specifically it sounds choppy. I think this is because the fan motor is turning on and off out of sync with what it is designed to do. Most PWM fans are purchased in order to reduce the speed of the fan in order to reduce the noise the fan is making so this is a key feature.

Configuring the fan frequency would be a setting configured once at setup.

Unfortunately most fans that are purchased do not specify this type of detail in their manual. I found an example datasheet of a PWM fan that provides the details.

https://www.delta-fan.com/Download/Spec/BUB0712HD-SM.pdf