Cooling fan controler

[yardman]

Hello all
I have a sump/refug in the basement and it keeps the display tank stable and cool if the fan is on but it also makes the heater run more than it should (trying to control elec cost's).I would like idea's on how I can setup a low cost controler to turn on the fan when water temp go's over set limit the off when it cool's .Other than this the basement sump has been great,it removes the noise ,stablizes the tank and make's water change almost automatic.

Thanks Craig

[Geoff]

i am not a electronics person, but i have seen a temp controlled fan at HD. i did not look much at it, but i saw one. something to at least back engineer or modify for the purpose.

HTH,

G~

[Phishnoob]

On page 495 at www.mcmaster.com they have a High-Low temperature alarm towards the bottom of the page. One kind there has two relay outputs that can handle one amp each and the liquid sensors are accurate to half of a degree. If worse comes to worse you can use the little relay output to drive a bigger relay if you are using a big fan. The other relay can be used to sound a remote alarm light or buzzer.

[Bvoss]

I hope it is OK to post a link to an old RC thread.

http://reefcentral.com/forums/showth...ight=cheap+fan

If you look at the post by eastn, you will see a simple DIY circuit for adjustable speed thermally controlled DC fans. I have been using it for almost 2 years and it is outstanding!

Bill

[reefer769]

i just bought a pair of fans off of ebay, they have a senor probe. so when the hood gets hot they speed up, when it cools down they slow down. they keep my tank at 80 degrees. the ebay sellers name is reponweb.