Improved Leakage Protector Used in Coal Mine by C8051F

A leakage selection protector to control low-voltage power network by C8051F micro-controller was introduced in this paper, and its working principle, soft structure, characteristics were also introduced. The device was designed with intrinsical and safe circuit, and adapt to low-voltage systems of 380 V, 660 V, 1140 V. It has high reliability.