electronics project for school.

[devcrow]

hey,
this year, as always, i have to do an electronic project. i was hoping you guys could help me with some ideas.

my main idea right now is having a cpu and grafix temperture reader, and when the temp goes to a certian temp, 1 fan will turn on, when it goes to another temp another fan will turn on. etc etc.
but i think that will be problimatic...

im greatfull for any ideas
thanks in advance

 

[hazza]

you could somehow create a potential divider like this: http://www.kpsec.freeuk.com/images/vdivider.gif

and make r1 a thermistor. by playing around with the values of the resistor and the thermistor, you could make it so that v out has the correct voltage to power a fan, when the temperature of the thermistor gets to a certain level.

i made the proposed circuit in croc tech, and got it working, but im not sure about doing it in real life.

i may post some screenshots of the circuit later when i get time

harry

 

[devcrow]

yea that would be good, could integrate that into my main idea, thanks for the reply

keep them coming

 

[hazza]

ok, i have finally got round to sorting out the screenshots for you. here is the simple circuit:

here is the simulation of the fan not being on because the temperature is low (30degrees in this case) :

and here is the simulation of the fan being on because the temperature is high (40degrees in this case)

And by changing the values of the resistor, and using a different sized thermistor (as this one only measures up to 40degrees) you can change the temperature at which the fan turns on.


hope this helps in some way or another

harry