Subject: Temp Control
By: rockman20 (IP: 24.119.247.*)
Written on: 17-02-2008 15:55
I built your device and it worked wonderfully. I tested it with an old computer power supply and an old processor fan. I could get it to turn on and off perfectly.
Then I went to put it in the actual application. I am inserting it in my entertainment center to keep my components cool. Currently I am running 2 fans Approximately 4 Watts and .3Amps.
I have this powered by a 12 volt AC/DC adapter. I plugged everything in and the fans were already on. I tried to turn the potentiometer down but it wouldn\'t turn off. It\'s like the two fans blew something and I\'m not sure what.
I am not sure what to do. I wired the two fans in parallel.
This is what I used:
IRF510 Power MOSFET Transistor. N-channel 60Volt. (Radio Shack 276-2072)
10K-Ohm 15 turn Cermet Potentiometer .75Watts (Rado Shack 271-0343)
Thermistor 10K OHM +/- 0.20C (Digi-Key 615-1010-ND)
I know that the pot is only rated at .75 Watts. Could this be my problem? Perhaps it blew the pot?
I was thinking about adding another 2 fans to my setup so there would be 4 total. I was thinking about perhaps inserting a relay into the circuit? What do you think? Please take it easy on me! I have dabbled with electronic circuits, but am still very wet behind the ears. Thanks!!!!!