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Old 02-03-2015, 06:41 PM   #1663 (permalink)
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Here's a good resource for them; it's better than I can explain..

One way to address the input impedance issue is to put a small capacitor from signal>ground. The thermistor isn't going to change output very rapidly, and the capacitor will just follow it's output. You don't need to add all the complexity of an op-amp buffer, because the response is so slow.

Also, I just got an e-mail regarding the motor. Same price, and they'll ship it to you for $30. They must have some special discount shipping arrangement. I'm just waiting to hear if it's in as good a condition as the one I have.

- E*clipse

Originally Posted by MPaulHolmes View Post
Is there a curve anywhere for temperature vs voltage reading? And it's a 50k thermistor? I think microchip recommends to have <= 4.7kOhm impedance on the A/D input. Does that mean I would need an op amp voltage follower to create a lower impedance?
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