Скачать или смотреть Fan PWM control with Arduino sensor temperature and RPM speed

4 pin fan with PWM / Pulse Wave Modulation
More easy compare voltage regulator

Speed RPM fan can adjust, example
For cooling with temprature range
For high load electronic and generate heat, need fan for cooling

Note
Almost PWM Fan have minimum RPM
Between 25%, 30% 50%, 70% up to 100% speed RPM
Only a few model fan 0 RPM
Old mode fan sensor, have internal NTC sensor. Fan increase speed if temperature increase above 45 deg.C and turn RPM maximum speed after sensor detect 45 deg.C

Using program, speed fan and temperature range can be program
http://obengplus.com/artikel/articles...

00:00 Make fan control and temperature demo
00:26 Schematic wires
00:34 Sensor BMP280
00:45 Arduino Nano and OLED pin
01:06 ESP8266 pin
Without LED, wire connection fan controller ESP8266
Only need 5 pin, 4 for sensor, 1 for PWM signal to fan.
Other input power 12V
01:19 Display Fan, Speed, and Temperature
OLED only optional
01:42 Using ESP8266 Fan Control PWM
Can show fan speed, RPM etc via Web browser and connact to LAN
02:00 Minimum fan PWM speed
Not all fan the same minimum RPM fan speed
Intel fan Nidec FA09-12B1S1, minimum 50%
Intel fan Nidect F09A-12B1S2, minimum more lower 20%, silent fan, but low speed fan
04:24 Aplication cooling PWM Fan and Arduino