PWM Fan Controller using PIC12F675 microcontroller
PWM Fan Controller
The heart of the PWM Fan Controller is a PIC 12F675 microcontroller. This microcontroller is reading the analog output of a LM35 temperature sensor using a ADC (analog to digital converter) . The resulting digital value is converted to a temperature and a fan is powered proportionally to how hot the sensor is. The sensor is mounted against the hard drive chassis so it is measuring the actual drive temperature and not just the air temperature inside the housing.
PWM Fan Controller – Parts
PWM Fan Controller – LM35 Sensor Overview
PWM Fan Controller – Reading Data with the Microcontroller
The analog input has a range of 0 to 5 volts and the digital resolution is 10 bits. This means that the 0 to 5 volt range will be represented by a number from 0 to 1023 in the microcontroller. If we divide 5 volts by 1024 we get the number of volts per digital increment. In this case it is 0.004883 volts per increment. So if the voltage was 1 volt on the microcontroller pin we would expect to have a reading of around 204 as the digital number (1/0.004883).
From Schematic to PCB Production, Just Need One Tool
Free Circuit Design Software: learn to use Editor quickly and easily
Cheapest PCB: 10pcs 2-layers 10cm×10cm only $8.21, 3-day build time, 100% E-test
Current Project / Post can also be found using:
- pbp pic ac fan dimmer#imgrc=_
- pbp pic12675 fan remote
- pbp pic 12f675 fan regulayer
- pbp pic 16f675 ac fan control