thermistor fan issue

greenroomguy · 04-23-2008, 03:18 PM

I am using two 'Silenx Ixtrema 120 pro series' thermistor controlled fan in a non-computer related application. Both are connected to a 12v power supply along with a fan-equipped heatsink. The heatsink is cooling a light fixture(mounted on top of case). One fan is pulling warm air through 4" duct to cool said light fixture. Fan no.2 is introducing cool air to the small room(4'x4'x6.5'). Incase you have not guessed, this room is host to a small hydroponic farming operation.

I cut off the three-wire connectors, connected the + and - leads to 12v and all of my fans worked beautifully(middle of hot day). On the next day(cool of morning), the fan pulling in cool outside air was at a dead stop. There are no physical obstructions.

Do I need to connect the control wire to something?

Can I somehow bypass the thermistor for a continuous run speed?

I am not the most computer savvy guy in the world, but I am a trained commercial electrician so I understand basic electronic principles pretty well.

PLEASE HELP!

**magnethead** · 04-23-2008, 08:07 PM

well, not really. not without altering the fan, anyways.

04-23-2008, 03:18 PM	#1 (permalink)
greenroomguy Registered User Join Date: Apr 2008 Posts: 1 OS: xp	thermistor fan issue I am using two 'Silenx Ixtrema 120 pro series' thermistor controlled fan in a non-computer related application. Both are connected to a 12v power supply along with a fan-equipped heatsink. The heatsink is cooling a light fixture(mounted on top of case). One fan is pulling warm air through 4" duct to cool said light fixture. Fan no.2 is introducing cool air to the small room(4'x4'x6.5'). Incase you have not guessed, this room is host to a small hydroponic farming operation. I cut off the three-wire connectors, connected the + and - leads to 12v and all of my fans worked beautifully(middle of hot day). On the next day(cool of morning), the fan pulling in cool outside air was at a dead stop. There are no physical obstructions. Do I need to connect the control wire to something? Can I somehow bypass the thermistor for a continuous run speed? I am not the most computer savvy guy in the world, but I am a trained commercial electrician so I understand basic electronic principles pretty well. PLEASE HELP!

04-23-2008, 08:07 PM	#2 (permalink)
magnethead TSF Enthusiast Join Date: Mar 2006 Location: TX Posts: 819 OS: XPH, 2K My System Blog Entries: 2	Re: thermistor fan issue well, not really. not without altering the fan, anyways. __________________ I'm not the world's greatest speller. Deal with it.