Abstract: In recent years, smart home systems have achieved rapid development. Single live wire power supply system is an important part of it. However, traditional offline power supply circuit is difficult to adapt to its working environment. New structures are in dire need of development. Aiming at the characteristics of extremely low working current of single live wire power supply system, the traditional structure of RCC switching mode circuit is modified to reduce its working current. The working current is significantly reduced. After circuit simulation, a actual product is produced and the measured working current is only 0.8 mA in test, which is more than 50% lower than that in traditional structure. It is proved to have high practical value with simple structure, stable performance, and low cost.

Key words: Single live wire, Intelligent switch box, RCC, Switching mode power supply