Patent ID: 7428133

Claim:
A protective device of a surge protector comprising: a) a resistor having a resistor first end and a resistor second end; b) a first fuse having a first fuse first end electrically connected to a first power input end and a first fuse second end electrically connected to the resistor second end and a first power output end; c) a switching circuit is a transistor circuit having a switching circuit first end, a switching circuit second end, and a sensing end, the switching circuit first end is electrically connected to the resistor first end, the switching circuit second end is electrically connected to a second power output end; d) a surge protector having a surge protector first end and a surge protector second end, the surge protector first end is electrically connected to the second power output end; and e) a second fuse having a second fuse first end electrically connected directly to the first power output end, the resistor second end, and the first fuse second end, and a second fuse second end electrically connected to the surge protector second end and sensing end of the switching circuit, wherein when the sensing end senses a low potential, the switching circuit is turned on heating the resistor and opening the first fuse thereby cutting off a power source, wherein the surge protector and the second fuse are connected in series between the first power output end and the second power output end.