How to Apply NTC Thermistors 2

Figure 2: Using NTC to Stabilize the Operating Point of Transistors

In Figure 2 (b), the NTC thermistor liver is connected in parallel with the emitter resistor. When the resistance of the transistor emitter junction increases with temperature, the NTC thermistor RT acts as a compensation.

Figure 2 (c) shows the low-frequency power amplification stage of a transistor radio. A NTC thermistor RT is connected in parallel to the lower bias resistor of this stage. When the temperature increases and the collector current increases, the base current also decreases due to the decrease in the lower bias resistor, which stabilizes the operating point. diode

3) Using NTC thermistor as temperature measuring device

Figure 3 shows a thermistor thermometer. In the figure, RT represents a thermistor. As the resistance of the thermistor changes with temperature, the microampere meter connected between the diagonals of the bridge also changes accordingly. The accuracy of a thermistor thermometer can reach 0.1 ℃, and the temperature sensitivity is below 10 seconds.diode

Figure 3 Thermistor thermometer