Abstract: With the continuous development of power line carrier technology, the advantages of power line carrier communication are becoming increasingly apparent. This paper introduces an automatic control system that uses the LM1893 integrated chip to implement power line carrier communication, with a PC acting as the host computer for comprehensive information processing, and a microcontroller acting as the slave computer to control the electrical equipment. Multi-machine communication between the PC's RS232 serial port and the microcontroller is achieved via serial communication. The design method described in this paper is then applied to a classroom energy-saving system, achieving the desired design effect. Keywords: Power line carrier; Single chip; Energy conservation Abstract: With the development of carrier-current technology, the predominance of carrier-current communication is becoming increasingly apparent. This article introduces an auto control system that implements carrier-current communication using the LM1893 IC, manages information synthetically by a PC, and controls the electro-equipment using a single chip. Communication via an RS232 serial port on the PC and multiple single chips is achieved through serial communication mode. The energy conservation system in the classroom is implemented using the method described in this article, achieving its design purpose. Key words: Carrier-current; Single chip; Energy conservation Introduction With the increasing maturity of power line carrier communication technology, research on power line carrier has gradually become a hot topic. Power line carrier communication uses power lines as the transmission channel. Since low-voltage power lines are ubiquitous, using existing low-voltage power lines for signal transmission eliminates the need to build dedicated communication channels. System equipment can be connected to power lines locally, significantly reducing communication costs, requiring less investment, yielding quick results, and allowing for synchronous construction with the power grid. Power line carrier communication technology can be widely used in industrial automatic control systems [1-2], automatic meter reading systems [3], medical fields [4], electrical equipment control systems [5], fire alarm systems [6], and other applications. Power line carrier communication demonstrates its unparalleled advantages in many fields. This paper introduces a method for implementing power line carrier communication using the LM1893 integrated chip and develops a power line carrier communication device based on single-chip microcomputer control. For details, please click: Research on Automatic Control Systems Based on Power Line Carrier Communication