Temp. measurement circuit using variable resistor - uses ration between supply voltage and sensor voltage drop to give temp. indication

摘要

The circuit uses a temp. sensitive sensor whose resistance change generates a corresponding voltage change which is measured and compared with a reference voltage. The measured voltage also indicates the sensor temp. A variable voltage source delivers several voltages. The first voltage generates the reference voltage, and the second supplies the sensor. The sensor is a part of a voltage divider to which the suply voltage is applied, and from which the measurement voltage is collected. The voltage source voltage serves as a reference voltage, and the ratio between the supply source voltage and the measurement voltage is used for temp. display.