Heating plate control circuit of nucleic acid extractor

The utility model relates to a control circuit for a heating plate of a nucleic acid extractor. The control circuit comprises a power supply sub-circuit, an STM32 main control circuit, an RS232 communication interface circuit, a heating circuit, an overheat protection circuit and a temperature detection circuit. The power supply sub-circuit is used for outputting stable 3.3 V voltage to supply power to the whole heating plate control circuit; the STM32 main control circuit is used for receiving temperature signals from the RS232 communication circuit and the temperature detection circuit and outputting heating control signals to the heating circuit; the RS232 communication interface circuit is used for carrying out two-way communication of temperature control with the STM32 main control circuit; the temperature detection circuit is used for generating a temperature signal of a current heating point and transmitting the temperature signal to the STM32 main control circuit; the overheating protection circuit is