Bypassing thermister and temperature controlled devices

Doramius

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Mar 24, 2013
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This is meant for instruction, and not a question. (I believe this is in the correct place, but if it is not, feel free to move it, or let me know correct placement, and I will move immediately. My apologies in advance.)

I tried searching for How To's in the forums, but haven't found anything related to it. Please only post instructionals in this thread for bypassing temperature controlled devices. This is not specifically related to overclocking.
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Generally speaking, a thermister is a resistor that is sensitive to/affected by ambient heat. When the ambient heat changes, it's value will change. You can bypass it with a regular resistor, but you have to know the value associated with the thermister.

To find the value:
-Disconnect the thermister, and apply a meter to it and read initial resistance value.

-You can try pinching the thermister between thumb and forefinger to increase the temp and read the change in resistance. That'll help give a range of resistance.

-For a more accurate reading, get a glass of luke warm water and a thermometer. Increase or decrease heating of water to the desired temp (genernally the max temp dealt with in computers is between 120F-140F). while connected to your meter, place the thermister in a plastic baggie, and hold gently under water for a few seconds, reading the resistance value on your meter. wait for the reading to stabilize to get a proper value.

Now you can get the correct resistor to replace the thermister.
 
all very well and good... but you didnt include what practical application this would have.

you certainly do not want to bypass any temperature probes on a pc motherboard and bypassing any thermal probes on other equipment likely isnt a good idea either. the only time i can see replacing a thermister with a resistor is when you are having issues with the thermister tripping when it should not be and you know for sure that temperatures are fine.
 

Doramius

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Agreed. This was just a How To. Knowing what a thermister is and it's function is very good information to know. This information was originally provided for someone wanting to replace a thermister on an aftermarket device, to which they wanted to be able to manually control. There are plenty of practical uses for bypassing a temperature sensor. It is wise to know what sensor you are replacing, and for what reason, to prevent potential damage to the device.