NTC thermistors in series in the AC circuit plays a role of “current insurance”.
NTC thermistors in parallel in the AC circuit plays a role of “limit overvoltage”. Frequent on/off is not allowed when using NTC thermistor in the power supply for startup surge suppression. Restarting is allowed when NTC thermistor cooled down to a cold resistance. Otherwise, NTC thermistor in the circuit will have little effect.
7. NTC thermistor in medical electronic thermometer
Nowadays, many large hospitals use electronic thermometer, which has a short measurement time, a high accuracy, and a memory function. It’s also easy to read. It performs well in clinical use. There are four components in the thermometer, heat detector, signal processing unit, display and power supply. Heat detector is a sensitive component, which generally applies one or more high accuracy fast response NTC thermistors. This is closely related to the accuracy and response speed of output temperature; signal processing unit has two algorithms, heating and calculating.
Physical photo of NTC thermistor
