Patent ID: 6775121
Filing Date: 2004-08-10
Classification: H02H,H04M

Abstract:
A power line surge protection device comprising:an AC plug comprising a first conductor for connection to an AC line, a second conductor for connection to an AC neutral, and a third conductor for connection to a ground; at least one female outlet, each outlet comprising a first, a second, and a third conductor connected, respectively, to the first, the second, and the third conductors of the AC plug; an overvoltage protection circuit, the circuit comprising: at least one temperature sensing fuse connected in series with the AC line; at least one temperature sensing fuse connected in series with the ground; a three electrode gas tube connected to the AC neutral; at least one metal oxide varistor (MOV) connected between at least one temperature sensing fuse connected in series with the AC line and the three electrode gas tube; at least one MOV connected between at least one temperature sensing fuse connected in series with ground, and the three electrode gas tube; at least one diode connected between at least one temperature sensing fuse connected in series with the AC line and at least one MOV connected between at least one temperature sensing fuse connected in series with the AC line and the three electrode gas tube; a first resistor connected in series with at least one diode; and a first indicator connected between the first resistor and the AC neutral; a ground-sensing indicator circuit, the circuit comprising: a second resistor connected in series with the AC line; a diode connected in series with the second resistor; a transistor including a base, an emitter, and a collector, the collector connected to the AC neutral; a second indicator device connected between the diode and the emitter of the transistor; a third resistor connected between the ground and the base of the transistor; a capacitor connected between the AC line and the AC neutral; a zener diode connected in series with the AC line; and a third indicator device connected between the zener diode and the AC neutral.