Idiots guide to getting an esp32 to control AC Infinity Cloudline EC fans esphome/HA

sle118

Member
Hi guys,

I'm not a EE, I only know basic electronics, but I want to be able to control the speed of a S8 fan that I got this year (UIS connector). It has a manual speed controller but I want to be able to control the speed with either EPS32 or Arduino, and eventually integrate it into Home Assistant.

I tried to read this thread in its entirety but due to my limited EE knowledge, it's hard to follow. Can someone more knowledgeable summarize the key learnings please? I think what I got from it is that it uses a 10V PWM, at perhaps 5000 HZ. I know a little bit about MOSFET and PWM. I wonder what's the simplest circuit I can build to do this? Moreover, there's some historical changes between the MOLEX connector and the UIS which further makes this thread hard to follow.

Is it possible to achieve what I need without messing with the circuitry/wires inside the fan electronic box? In other words, just build an external DIY controller that connects to the fan using UIS (or USB-C?).

Someone please make it a truly idiot's guide. Thanks
You got it right. I'm sure you can achieve control without needing with wires, but you'd have to confirm the pins on the connector.

PWM is 4,156hz on my S4. See my measured trace here at various duty cycles:


The fans are likely tolerant to some level of deviations, though, and it is also possible that other models have slightly different frequencies but unless someone plugs in a scope of other models, your guess is as good as mine.

Your best bet is to at least open the fan case to peek inside and see for yourself what connections are there. @ImaginaryTango posted a nice picture of his unit and this is likely resembling yours as well.

My take on the base circuit is here.

You can skip the fuse if you feel lucky. You can also skip the tachometer gpio too, although it's simple to add and brings interesting stats back.
 
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engineheat

New Member
You got it right. I'm sure you can achieve control without needing with wires, but you'd have to confirm the pins on the connector.

PWM is 4,156hz on my S4. See my measured trace here at various duty cycles:


The fans are likely tolerant to some level of deviations, though, and it is also possible that other models have slightly different frequencies but unless someone plugs in a scope of other models, your guess is as good as mine.

Your best bet is to at least open the fan case to peek inside and see for yourself what connections are there. @ImaginaryTango posted a nice picture of his unit and this is likely resembling yours as well.

My take on the base circuit is here.

You can skip the fuse if you feel lucky. You can also skip the tachometer gpio too, although it's simple to add and brings interesting stats back.
Thanks. I did read that someone was able to build a controller without modifying the internal electronics of the fan, such that they can still use the AC Infinity manual controller if needed. I also read that there is a 10V line inside and the PWM is coming off that. That 10V is DC, so is the motor actually a DC motor despite the S series being AC (in the sense you plug it into 110 - 220V AC)? Or is the 10V just for PWM?

It also seems like there the 10V for the PWM is being pulled up, such that when there is no controller connected, the fan is at full speed, and the purpose of the controller is to short it to ground in a periodic manner to achieve PWM. Did I understand it correctly?
Thanks
 

sle118

Member
Thanks. I did read that someone was able to build a controller without modifying the internal electronics of the fan, such that they can still use the AC Infinity manual controller if needed. I also read that there is a 10V line inside and the PWM is coming off that. That 10V is DC, so is the motor actually a DC motor despite the S series being AC (in the sense you plug it into 110 - 220V AC)? Or is the 10V just for PWM?

It also seems like there the 10V for the PWM is being pulled up, such that when there is no controller connected, the fan is at full speed, and the purpose of the controller is to short it to ground in a periodic manner to achieve PWM. Did I understand it correctly?
Thanks
Yes you understood correctly. None of the suggestions here modify the inner circuit of the fan. Opening the fan cover merely gives you a different access to the wiring. Sending a PWM is a substitute for the out of the box controller. My post with scope captures were taken from the controller that came with the fan.
 
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