Hi
I have an ESP32
that I plan to connect to a MOSFET Driver Module to be able to control a 12v fan 3pin, but do I need a relay after to be able to turn it off at a certain temperature, or can I still do without a relay?
Hi, and welcome.
Why do you think temperature is a factor? Will there be extreme temperature? Also since we're not telepathic, you should present what module you have.
Hello,
I don't get it
What were you planning to control with the MOSFET if it's not weither it turns or no?
Yes a MOSFET (that you need to choose well) can be used to control the fan.
I think it's more in the case where the temperature is low enough and the fan isn't required to cool down anything
A MOSFET triggered by a temp sensor is a decent solution.
He definitely would need a schmitt trigger to prevent oscillatation between on and off each 2sec
Thanks for all the answers
Mosfet should be used to 12v to 5v to esp32 then be able to pwm control 12v fan, then the idea was to be able to turn off, on the fan at certain temperatures using a relay
(post deleted by author)
But if you give no PWM signal the fan won't turn, you know that right?
You don't need to add a relay
BTW an ESP32 works in 3.3V, not 5V
Sounds logical.
Welcome aboard.
Sorry what? 
#9 sums up where I was going from the start. Why relay if there's a FET, what module so we can tell if it's suitable for 3.3 V operation.
RE post #9, the fans I delt with would spin at 100% with open PWM input wire because of internal circuitry. Setting the PWM input to 0% allowed the fan to run at minimum RPM. So, the fan will not stop with a grounded PWM input. Check the fan data sheet for exact details.
feels more like I don't need the relay at all in my connection, will I still be able to turn it off in certain temperature conditions
if so then for example skip the relay completely and just run Esp32 to Mosfit Driving Module?
Lets start from beginning.
You want to control a fan based on temperature, and do this with a ESP32. Correct so far?
Now, what fan do you have and what MOSFET module? What inputs the temperature into the ESP32?
Sounds like a good start
have a Noctua 12v Pwm
which I plan to connect to mosfit https://whadda.com/product/mos-drivin
g-module-wpm411/
then be able to control the 12v fan via an esp 32, but then the question is whether it is easiest with or without a relay, it can be thought of as being able to easily turn off the fan with the relay,
Almost there. Link?
Tht seems to be a useless module with a non-logic level IRF520 fet, which is a poor choice for 5volt-logic. and totally unsuitable for the 3.3volt-logic of an ESP. But you might not need anything to control a 3-pin fan. Just connect an ESP PWM output to the PWM input of the fan.
Note: not all Noctua fans can be turned off. Some have a minimum speed.
Leo..
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thanks for the answer,
but then maybe it won't work as I think,
the idea is to be able to control the 12v fan via 3pin
then be able to control in certain temperature conditions via Home assistance
but then maybe the Pwm control won't work as I thought