Fault powered, processor controlled circuit breaker trip system having reliable tripping operation

Claim 2

A tripping system for interrupting a current path, comprising: means for interrupting the current path in response to a trip signal; a power supply for providing power to the means for interrupting to effect the current path interruption; power supply sensing means, coupled to the power supply, for indicating whether or not the power supply is presently capable of supplying the means for interrupting with a sufficient amount of power to effect the current path interruption; a current sensor for sensing current in the current path; and generation means, responsive to the current sensor and the power supply sensing means, for engaging the means for interrupting when the power supply sensing means indicates that the power supply is presently capable of supplying the means for interrupting with a sufficient amount of power to effect the current path interruption.

Claim 3

A tripping system, according to claim 1, wherein the power supply receives current from the current path.

Claim 4

A tripping system, according to claim 2, wherein the current sensor includes a coil inductively linked to the current path, and the power supply includes a capacitor charged by current rectified from current induced in the coil.

Claim 5

A tripping system, as claimed in claim 1, wherein the generation means includes a processor programmed to determine when the current through the current path has become excessive and input data from the power supply sensing means before engaging the means for interrupting.

Claim 6

A tripping system, according to claim 4, wherein the processor further includes means responsive to the fault signal for repeatedly checking the power supply sensing means until the power supply sensing means indicates that the power supply is presently capable of supplying the means for interrupting with a sufficient amount of power to effect the current path interruption.

Claim 9

A tripping system for interrupting a current path, comprising: a sensing circuit for sensing at least one power-related parameter in the current path; an interruption circuit for interrupting the current path in response to a trip signal; a power control circuit, drawing power from the current path and including at least one power signal, for providing for sufficient power to the interruption circuit to effect the current path interruption; a comparison circuit, coupled to the power supply, which indicates if said at least one power signal is greater than a predetermined value; and means, including a microcomputer for analyzing said at least one power-related parameter, for engaging the interruption circuit in response to the analysis of said at least one power-related parameter and to the comparison circuit indicating that said at least one power signal is greater than a predetermined value.

Claim 10

A tripping system for interrupting a current path, comprising: a sensing circuit for sensing at least one power-related parameter in the current path; an interruption circuit for interrupting the current path in response to a trip signal; a power control circuit, drawing power from the current path and including at least one power signal, for providing for sufficient power to the interruption circuit to effect the current path interruption; a comparison circuit, coupled to the power supply, which indicates if said at least one power signal is greater than a predetermined value; and means, including a microcomputer for analyzing said at least one power-related parameter, for engaging the interruption circuit in response to the analysis of said at least one power-related parameter and to the comparison circuit indicating that said at least one power signal is greater than a predetermined value.

Claim 11

A tripping system, according to claim 7, wherein the comparison circuit includes a digital buffer which generates a logic low when said at least one power signal falls below said predetermined value.

Claim 12

A tripping system for interruption at least one of a plurality of current paths in a multi-phase network, said tripping system comprising: a plurality of sensing circuits for sensing current in each of the plurality of current paths; a plurality of rectification circuits, respectively coupled to said rectification circuits; a power control circuit, drawing power from the current path through said plurality of rectification circuits, said power control circuit providing sufficient power to the interruption circuit to effect the current path interruption; at least one burden resistor coupled between the power control circuit and at least one of said plurality of rectification circuits for developing a voltage signal which corresponds to said at least one power-related parameter in at least one of the current paths; at least two amplification circuits, arranged in parallel so that both receive said voltage signal and each having a different gain for amplifying said voltage signal so as to amplify the voltage signal in varying degrees of resolution; an interruption circuit for interrupting the current path in response to a trip signal; a comparison circuit, coupled to the power supply, which indicates if said at least one power signal is greater than a predetermined value; and means, including a microcomputer for analyzing said voltage signal through said at least two amplification circuits, for engaging the interruption circuit in response to the analysis of said at least one power-related parameter and in response to the comparison circuit indicating that said at least one power signal is greater than a predetermined value.

Claim 13

A tripping system for interruption at least one of a plurality of current paths in a multi-phase network, said tripping system comprising: a plurality of sensing circuits for sensing current in each of the plurality of current paths; a plurality of rectification circuits, respectively coupled to said rectification circuits; a power control circuit, drawing power from the current path through said plurality of rectification circuits, said power control circuit providing sufficient power to the interruption circuit to effect the current path interruption; at least one burden resistor coupled between the power control circuit and at least one of said plurality of rectification circuits for developing a voltage signal which corresponds to said at least one power-related parameter in at least one of the current paths; at least two amplification circuits, arranged in parallel so that both receive said voltage signal and each having a different gain for amplifying said voltage signal so as to amplify the voltage signal in varying degrees of resolution; an interruption circuit for interrupting the current path in response to a trip signal; a comparison circuit, coupled to the power supply, which indicates if said at least one power signal is greater than a predetermined value; and means, including a microcomputer for analyzing said voltage signal through said at least two amplification circuits, for engaging the interruption circuit in response to the analysis of said at least one power-related parameter and in response to the comparison circuit indicating that said at least one power signal is greater than a predetermined value.