Patent ID: 6650515
Filing Date: 2003-11-18
Classification: H02H

Abstract:
A circuit breaker comprising:separable contacts; an operating mechanism for opening and closing said separable contacts; a power supply comprising an input adapted to receive an alternating current voltage, a regulator adapted to regulate a first direct current voltage having a first polarity, a first output adapted to provide the first direct current voltage, and a second output adapted to provide a second direct current voltage having a second polarity which is opposite the first polarity; a trip mechanism cooperating with said operating mechanism, powered from the first output of said power supply, and responsive to electrical conditions of said separable contacts for tripping said separable contacts open, said trip mechanism having an input for disabling said tripping; and a power supply monitor circuit comprising: a node adapted for electrical connection to a ground, a first resistor electrically connected in series with the regulator of said power supply, a first transistor having two inputs electrically connected in parallel with said first resistor and having an output, a first capacitor electrically connected between the first output of said power supply and the output of said first transistor, a second resistor electrically connected in series with the first capacitor between the first and second outputs of said power supply, a second transistor having a first input electrically interconnected with the output of said first transistor, a second input and an output, a diode electrically connected between the node and the second input of the second transistor, and an interface between the output of the second transistor and the input of said trip mechanism.