1. Explain the circuit principle through the introduction of electronic components and electronic circuits. Practice drawing circuit diagrams with Fritzing circuit drawing software. Use a variety of experimental teaching to encourage students to operate by themselves, so as to enhance students' interest in studying science, cultivate students' operational ability and stimulate students' creativity. 2. The learning process will add refrigeration and air-conditioning and energy-related knowledge, so that students can learn in detail: refrigeration and air-conditioning project planning and design, installation and construction, industrial safety and health precautions, and improve students' participation in "energy technology", "refrigeration", and "energy technology" Confidence in the three core technologies of air-conditioning, and cultivate the ability to combine practice and theory.