"电热水器温控系统硬件设计与实验"

Abstract The electric water heater is widely used in daily life, and automatic temperature adjustment can bring more convenience. This paper studies the relevant issues of the design of the automatic temperature control system of the electric water heater controlled by a single chip microcomputer. According to the design principles of high reliability, strong practicality, and convenient operation, a reasonable structure of the electric water heater temperature control system is designed: the paper analyzes the system design requirements and various performance indicators, discusses the selection issues of various components, proposes a scheme of using an 8-bit single-chip microcontroller 89S51 and DS18B20 temperature converter to form a temperature acquisition system, which has higher cost performance compared with the temperature acquisition system using a 16-bit single-chip microcontroller and thermistor plus A/D converter; in order to improve the temperature control accuracy, digital PID control is adopted, which can achieve continuous and adjustable temperature; in order to improve the anti-interference ability and drive capability of the stepper motor, Schmitt trigger and Darlington power amplifier are used as the stepper motor drive in the design; to enhance the safety performance of the system, a watchdog and a sound and light alarm circuit are also added in the design; finally, an engineering prototype is made and hardware simulation debugging is carried out. The actual debugging results show that the hardware design basically meets the required technical indicators, and comparative analysis shows that this device has good application prospects. Keywords: single-chip microcontroller; temperature conversion; stepper motor; DS18B20