Temp Fan Control Speed Easy to Buid and Adapt

simple,reliable,usefull and a lot of fun doing it :)

In my diy activity often need an smart simple and easy to adapt 5-12v fan control,because the fan is very noisy at full speed and very low lifespan.

I have tried a lot of schematic for fan control,but each one has his limits:

-has tl413 and hard to modify

-parts that are hard to find

-very hard to make the fan start only over 40 degree celsius,etc

I did not make this schematic,i reverse engineering from an expensive pc power supply.

it is very easy to understand and adapt to yours needs,parts easy to find from scraps.

I made this with original parts,and adapt for 10k NTC from bad laptop battery.

If u put 10K NTC you will divide by 10 all the resistors excepting R4.

when the temperature increase R5 decrease,and the drop voltage on R3 will close q2,q1 and the fan will start to spin.

R4 is limiting base current of Q1

R1 is the negative feedback,and with R2 is seting the default speed of the fan.

C1 is starting the fan when u start the device

Q1 is usual PNP with minimum 1A curent and minimum 30V Vce

Q2 is usual PNP with minimum 30V Vce

you can see here how to made this,and if u want to see how it works and test u can see the video

if u do this,pls put a coment and describe your experience

if u like this project,pls like and subscribe

Recycle and be creative!