A sensor is a device that converts non-electrical signals into electrical signals. It is the primary link in realizing automatic detection and automatic control. It is widely used in industrial and agricultural production and people's daily life. At present, the course "Sensor Principles and Applications" has become a required course for electronics and automatic control majors in colleges and universities, and is increasingly valued by teachers and students. In particular, the combination of sensors and microcontroller courses can design and produce some simple and practical intelligent measurement and control systems, which has stimulated many students' interest in learning and further improved their hands-on ability. Therefore, it is of great practical significance to do a good job in teaching sensors.
There are many types of sensors with different principles. It is impossible to cover them all during teaching, but the explanation of classic types of sensors or commonly used sensors is essential. If divided according to principles, commonly used sensors can be divided into several categories such as resistive, capacitive, inductive, thermoelectric, photoelectric, and magnetoelectric. No matter what type of sensor, its structure can be roughly divided into three parts: sensitive element, conversion element, and conversion circuit. For the same type of sensor, if the functions are different, the corresponding sensitive components may change, but the conversion components and conversion circuits may be the same.
Many classic sensors are products from the 1960s and 1970s. Some of them can no longer meet the needs of current production practice, and students do not show much interest in learning. Therefore, it is necessary to expand some new content and present novel sensors that are often used in real life to students to improve the practicality of the sensor course and stimulate students' desire to explore. For example, the currently widely used PVDF piezoelectric film sensors, Hall sensors, biosensors, smart sensors, etc. are not only widely used, but also use newly developed sensing materials or advanced microelectronics technology, representing the future development direction of sensors.
Multimedia teaching has the characteristics of large amount of information, intuitive and easy to understand, which can greatly improve the efficiency of classroom teaching. The sensor course contains a large number of schematic diagrams and circuit diagrams. The use of multimedia teaching can effectively save time and expand classroom capacity. In particular, multimedia pictures and animations can be used to vividly display the physical structure and working process of the sensor. This not only makes the teaching process more vivid, but also arouses students' interest in learning and enhances the teaching effect.
Although there are many types of sensors, in terms of structure, they mainly consist of three parts: sensitive components, conversion components and conversion circuits. If every chapter is explained in this way, students will find it tedious. In teaching practice, four to six classes can be used for discussion-based teaching, allowing students to discuss in groups the working principle, structure and conversion circuit design of a certain sensor, how to overcome temperature errors, applications in real life, especially which systems use such sensors, etc. This can not only mobilize students' enthusiasm for learning, but also stimulate their desire to explore.
