Patent ID: 6707654
Filing Date: 2004-03-16
Classification: H02H

Abstract:
A protection device arranged on an electric current path between a power supply and a load unit including a stabilized power supply unit adapted to receive a voltage from the power supply, comprising:a switching unit including an FET having a source terminal and a drain terminal arranged on an electric current path between said power supply and the load unit; and an input end to which a voltage generated by the stabilized power supply circuit of the load unit is input as a control voltage, said control voltage turning on said FET in a case of forward connection in which a positive input terminal of the load unit connects to an anode of said power supply and a negative input terminal of the load unit connects to a cathode of said power supply, and turning off said FET in a case of reversed connection in which the positive input terminal of the load unit connects to said cathode of said power supply and said negative input terminal of the load unit connects to the anode of the power supply, said control voltage being applied to a gate terminal of said FET via said input end.