当温控开关打开时，若测得环境温度大于设定温度，则继电器吸合，启动压缩机工作；若测得环境温度小于设定温度，则继电器释放，压缩机停止工作。该实验可以应用于对温度控制精度要求不是很高的场合，例如，粮仓，电冰箱，空调，电饭锅等。如果配以通讯接口，可以做成多点温度检测监控系统。具有极强的扩展性。(When the temperature control switch is open, if the temperature of the environment is greater than the setting temperature, the relay is absorbed and started to work. If the temperature of the environment is less than the setting temperature, the relay is released and the compressor stops working. This experiment can be applied to occasions where temperature control accuracy is not very high, for example, granaries, refrigerators, air conditioners, electric cookers, etc. If equipped with communication interface, multi-point temperature monitoring and control system can be made. It has very strong expansibility.)