I am new to the forum and have limited electronics knowledge but am intrigued by it. We have alot of issues at work trying to maintain temperatures of multiple systems tied to the same fan and i want to come up with a control circuit that is cheap and easy to build. open to any ideas as i enjoy learning this stuff. as of now, i am thinking of using multiple (5+)negative coefficient thermistors wired in parallel so that the lowest resistance (highest temperature) will be able to energize an output to bring on a fan and when all ntc's are below a determined temperature, de-energize a fan. I have plenty of room for boards and transformers and will have 208v supply to work with. would an ic chip and pot be able to achieve this? Are there components readily available that will achieve what i want to do? the fan control will only draw about 1-2 amps. any advice or suggestions would be appreciated.