HOWTO using 4pin PC fan

[TrDA-hab]

0. About using 4pin PC fan.

• Using PWM.
• Using MultiPwm.
• Using DC18B20.
• Using Thermostat.
• About sizes PC fan.
• About PC fan (wikipedia).
• About Fan speed regulators.
• PC Fan datasheet.
• # 9238 (Home Assistant - no tested).
• # 11257 (Tachometer - no tested).
• # 3053 (Tachometer - no tested).

Practical use of the PC fan.

• An example of the practical use of the 4pin PC fan for home ventilation.
• An example of the fan assembly for Fireplaces and Heat Radiators.

4pin PC fan Wire Diagrams.

!!! cable coloring varies from fan to fan

Pin	Name	Color-1	Color-2	Color-3	Color-4
1	GND
2	+12VDC
3	TACH
4	PWM

1. Minimum configuration:

2. Midle configuration:

3. Maximum configuration:

Note:

Now (09/07/2021) Tasmota has no support for the TAСH (tachometer) sensor. Maybe support for the TAСH will be added at a later date.

Best regards,
TrDA.

[barbudor]

Hi @TrDA-hab
What kind of solid-state-relays are you using ?
Most of those I know are for an AC load

[barbudor]

Spasibo 👍
Now, I found this shop with a large selection: https://www.aliexpress.com/store/1240331/search?origin=y&SearchText=SSR

[TrDA-hab]

https://aliexpress.com/item/32671829582.html

[barbudor]

30A should be good for a PC fan 😂

[joba-1]

maybe not…

[TrDA-hab]

30A should be good for a PC fan 😂

why not )))

[DREEMus]

Guys, no one seen that DS18B20 are connected to 12V directly in midle configuration?

[TrDA-hab]

No. It must be connected to 3.3V.

[DREEMus]

Look once again on midle configuration, DSs are separated from 3.3V and are connected to 12V directly with fans.

[drcyberg]

Hi Masters!
I have a question about the 504.jpg circuit diagram:
Doesn't the TACH pin require a 4K7 3.3V pull-up resistor?
Isn't the signal only interpretable if there is an external pull-up?
Thank you!
Regards!

[sfromis]

By default, Tasmota will enable the ESP weak internal pull-up on most types of input pins, unless you explicitly configure to not do this. Hence no external pull-up needed.