PWM Fan Controller

You can see the PWM Fan Controller project here.

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.

Step 1: PWM Fan Controller - Parts

We have most of the items available in the online store.

* Pre-programmed PWM Fan microcontroller
* 0.1 uF Bypass Capacitor
* Blue LED
* 330 Ohm Resistor
* NPN Transistor
* Perfboard
* LM35 Temperature Sensor

Comments

[profpat]

this is great, i do have a hard disk double fan cooler that runs at full speed regardless of the temperature, with your design, it would be controlled according to the temperature..thanks for your contribution..

[Thereyouhaveit]

So how do i modify it for 12v usage ?

[abbtech]

In this circuit the fan is operating from 12 volts but the controller is running from 5 volts. If you want to operate it from a 12 volt power supply you would need to make the 5 volt supply using some electronics. Do a Google search for 7805 voltage regulator and you will find many examples on how to convert 12 volts DC into a nicely regulated 5 volt DC output.

[Thereyouhaveit]

Oh , the 7805 , okay , i know everything else :)

[Dragonhen]

Thanks for explaining so clearly how to assemble this project. ^_^.. Greetings from Chile.

[abbtech]

Thanks!

[abbtech]

Thanks. :)

[jimyopkins]

thanks a lot , I would like the schematic diagram if possible
I didn't find it here

[abbtech]

Hi Jimyopkins,

Click on the first link in the article and you will see the schematic. I didn't post it here since the Instructables resolution would make it non-readable.

[kelseymh]

This is great! Having a complete kit available for users who don't want to source their own is a good idea. We appreciate that you included the parts list; you might think about moving it up to the beginning (intro or before Step 1), but that's not critical. Rated and channel-featured.

[abbtech]

Thanks for the tip. You are right it flows much better this way.