# Tag Info

### Why is the output of the thermistor connected to the inverting terminal of the op-amp in this Texas Instrument IR thermometer schematic?

Looks like an approximate solution that ignores the 2nd order effect of nonlinearity on the sensor temperature offset. The sensitivity compensation is via modifying the ADC Vref with the NTC ...
• 409k
1 vote

### How to Calculate Thermistor Resistance?

That looks like a somewhat silly connection scheme, but anyway, if my interpretation is as below: simulate this circuit – Schematic created using CircuitLab Then \\$ R_T(V_{ADC}) = \frac{R49(...
• 409k

### How to Calculate Thermistor Resistance?

I assume you have the following equivalent circuit. simulate this circuit – Schematic created using CircuitLab Beta parameter equation is: $$Rt = Ro \; e^{B\; ({1 \over T} - {1 \over To})}$$ ...
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### How to Calculate Thermistor Resistance?

Basically you need to come up with an expression for the voltage divider sampled at the STM32, consisting of the NTC which is unknown or dependent on temperature. That is one equation. Then you get ...
• 309
Accepted

### How to Calculate Thermistor Resistance?

You should provide the part number for the Thermistor. First you should measure the resistance of your thermistor. Notice that it's forming a voltage divider of 5V where the high side is a fixed 10k. ...
• 7,134
1 vote
Accepted

### Troubleshoot negative reading from thermistor sensor when the projector powers on

You cannot expect to read the resistance with the sensor plugged in, let alone powered. There is some internal circuit that will shunt the resistance when it is plugged in (causing a lower resistance ...
• 409k

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