Abstract: A surge protection device has a pulse controlled switch, a pulse generation circuit and an abnormal voltage detection circuit. The surge control switch is connected in series to a power line loop and has at least one control terminal respectively connected to output terminals of the pulse generation circuit and the abnormal voltage detection circuit. An output terminal of the abnormal voltage detection circuit is connected to the power line loop and is located in the back end of the pulse controlled switch. The pulse generation circuit serves to send a pulse to the pulse controlled switch to close the pulse controlled switch and connect to the power line loop. When continuously detecting abnormal voltage in the power line loop, the abnormal voltage detection circuit opens the pulse controlled switch and disconnects from the power line loop so as to protect back-end equipment or circuit.

Abstract: A surge protection device has a pulse controlled switch, a pulse generation circuit and an abnormal voltage detection circuit. The surge control switch is connected in series to a power line loop and has at least one control terminal respectively connected to output terminals of the pulse generation circuit and the abnormal voltage detection circuit. An output terminal of the abnormal voltage detection circuit is connected to the power line loop and is located in the back end of the pulse controlled switch. The pulse generation circuit serves to send a pulse to the pulse controlled switch to close the pulse controlled switch and connect to the power line loop. When continuously detecting abnormal voltage in the power line loop, the abnormal voltage detection circuit opens the pulse controlled switch and disconnects from the power line loop so as to protect back-end equipment or circuit.