Interface NTC thermistor with microprocessor

AI Thread Summary
The discussion revolves around interfacing an NTC thermistor with a microcontroller for temperature limit control using a comparator op-amp. A circuit diagram is requested to illustrate this setup, emphasizing the need to avoid direct electrical connections between the sensor and the controller. One proposed solution involves using an optocoupler, specifically a LED and photodiode configuration, to transmit the signal from the comparator to the microprocessor. The user expresses uncertainty about drawing the components correctly and seeks assistance in refining their circuit design. Overall, the focus is on ensuring proper signal transmission while maintaining electrical isolation.
ilovescience85
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Homework Statement


A microcontroller for temperature limit control has a 0 V to 5 V
power supply. An NTC temperature sensor provides an input voltage
to a ・} 5 V comparator op-amp. Depending upon whether the
temperature is below or above the set limit, the output from the opamp
comparator will be low or high. It is undesirable for a direct
electrical connection to exist between the sensor and the controller.
Draw a circuit diagram to show how you could interface the NTC
sensor to the microcontroller. Resistor values are not required.

Homework Equations


N/A

The Attempt at a Solution


I have a diagram of a window comparator circuit (see attached) with the thermistors output being one of the opamp inputs. I think I could use a optics to transfer the signal from the comparator to the microprocessor. I was thinking of a LED to transmit the signal and a photodiode to receive it at the microprocessor, but I'm unsure how to draw this. Any help would be greatly appreciated.
Window Comparator.gif
 
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Do a web search on "optocouplers". You may get some ideas.
 
Yeah thanks I got some help from my buddy, just wanted to make sure I was drawing the components correctly. Never been great with electrical circuits.
Thanks for the reply.
 
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