Circuit breaker device including improved overcurrent protective device

Claim 2

An overcurrent protective device comprising first means adapted to be connected to an alternating current circuit for deriving therefrom a unidirectional voltage which is substantially proportional to the current in the alternating current circuit, second means connected to said first means for converting at least a portion of said unidirectional voltage to a first output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which is substantially proportional to the logarithm of the square of said first output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second output current which is substantially the antilogarithm of the logarithm of the square of said first output current, said second output current varying with subsTantially the square of the current in said alternating current circuit, a capacitor connected to said fourth means for accumulating a charge, fifth means connected to said first means and to said capacitor to be responsive to the current in said circuit for actuating said capacitor to be charged by the output current of said fourth means when the current in the alternating current circuit increases substantially a predetermined value and sixth means connected to said capacitor for providing an output when the charge on said capacitor reaches substantially a predetermined level.

Claim 3

The combination as claimed in claim 1 wherein said third means includes first and second transistors each having a base, an emitter and a collector with the base and the collector of said second transistor being connected, the base-emitter circuit of said first transistor being connected in series additive relation with the base-emitter circuit of said second transistor to produce said output voltage which varies with substantially the logarithm of the square of said first output current.

Claim 4

The combination as claimed in claim 2 wherein said fourth means includes first and second transistors each having a base, an emitter and a collector with the base and the collector of said first transistor being connected, and an additional means connected to said first transistor for supplying substantially a predetermined unidirectional current to the base-emitter circuit of said first transistor, the base-emitter circuit of said first transistor being connected in series circuit relation with the base-emitter circuit, the output voltage of said third means being applied across the latter series circuit to produce said second output current in the collector of said second transistor.

Claim 5

The combination as claimed in claim 2 wherein said fourth means includes an output transistor having a base, an emitter and a collector, the base-emitter circuit of said output transistor being connected to said third means to be responsive to the output voltage of said third means to thereby produce said second output current.

Claim 6

An overcurrent protective device comprising first means adapted to be connected to an alternating current circuit for deriving therefrom a unidirectional voltage which is substantially proportional to the current in the alternating current circuit, second means connected to said first means for converting at least a portion of said unidirectional voltage to a first output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which is substantially proportional to the logarithm of the square of said first output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second output current which is substantially the antilogarithm of the logarithm of the square of said first output current, said second output current varying with substantially the square of the current in said alternating current circuit, fifth means connected to said fourth means for producing periodic output pulses of current substantially equal in magnitude to that of said second output current, a capacitor connected to said fifth means for accumulating charge, sixth means connected to said first means and to said capacitor to be responsive to the current in said circuit for actuating said capacitor to be charged by said pulses of current when said current in the circuit increases to substantially a predetermined value and seventh means connected to said capacitor for providing an output when the charge on said capacitor reaches substantially a predetermined level.

Claim 7

An overcurrent protective device comprising first means adapted to be connected to an alternating current circuit for deriving therefrom a unidirectional voltage which is substantially proportional to the current in the alternating current circuit, second means connected to said first means for converting at least a portion of said unidirectional voltage to a first output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which is substantially proportional to the logarithm of the square of said first output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second output current which is substantially the antilogarithm of the logarithm of the square of said first output current, said second output current varying with substantially the square of the current in said alternating current circuit, fifth means connected to said fourth means for producing periodic output pulses of current substantially equal in magnitude to that of said second output current, a capacitor connected to said fifth means for accumulating charge, sixth means connected to said first means and to said capacitor to be responsive to the current in said circuit for actuating said capacitor to be charged by said pulses of current when said current in the circuit increases to substantially a predetermined value and seventh means connected to said capacitor for providing an output when the charge on said capacitor reaches substantially a predetermined level.

Claim 8

The combination as claimed in claim 5 wherein an additional means is connected to said third means and to said fifth means for actuating said third means and fourth means to operate only during the periodic output pulses of said fifth means.

Claim 9

The combination as claimed in claim 5 wherein said third mEans includes first and second transistors each having a base, an emitter and a collector with the base and the collector of said second transistor being connected, the base-emitter circuit of said first transistor being connected in series additive relation with the base-emitter circuit of said second transistor to produce said output voltage which varies with substantially the logarithm of the square of said first output current.

Claim 10

The combination as claimed in claim 7 wherein said fourth means includes first and second transistors each having a base, an emitter and a collector with the base and the collector of said first transistor being connected, and an additional means connected to said first transistor for supplying substantially a predetermined unidirectional current to the base-emitter circuit of said first transistor, the base-emitter circuit of said first transistor being connected in series circuit relation with the base-emitter circuit, the output voltage of said third means being applied across the latter series circuit to produce said second output current in the collector of said second transistor.

Claim 11

The combination as claimed in claim 7 wherein said fourth means includes an output transistor having a base, and emitter and a collector, the base-emitter circuit of said output transistor being connected to said third means to be responsive to the output voltage of said third means to thereby produce said second output current.

Claim 12

An overcurrent protective circuit for use with a three-phase alternating current circuit comprising first means adapted to be connected to all three phases of said circuit for deriving therefrom a unidirectional voltage which is substantially proportional to the highest of the three phase currents, second means connected to said first means for converting at least a portion of said unidirectional voltage to a first unidirectional output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which varies with substantially the logarithm of the square of said first output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second unidirectional output current which is substantially the antilogarithm of the logarithm of the square of said first output current, said second output current varying with substantially the square of the highest current in said alternating current circuit, a capacitor connected to said fourth means for accumulating a charge, fifth means connected to said first means and to said capacitor to be responsive to the current in said circuit for actuating said capacitor to be charged by said second output when said highest phase current in the alternating current circuit increases to substantially a predetermined value and sixth means connected to said capacitor for providing an output when the charge on said capacitor reaches substantially a predetermined level.

Claim 13

An overcurrent protective circuit for use with a three-phase alternating current circuit comprising first means adapted to be connected to all three phases of said circuit for deriving therefrom a unidirectional voltage which is substantially proportional to the highest of the three phase currents, second means connected to said first means for converting at least a portion of said unidirectional voltage to a first unidirectional output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which varies with substantially the logarithm of the square of said first output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second unidirectional output current which is substantially the antilogarithm of the logarithm of the square of said first output current, said second output current varying with substantially the square of the highest current in said alternating current circuit, a capacitor connected to said fourth means for accumulating a charge, fifth means connected to said first means and to said capacitor to be responsive to the current in said circuit for actuating said capacitor to be charged by said second output when said highest phase current in the alternating current circuit increases to substantially a predetermined value and sixth means connected to said capacitor for providing an output when the charge on said capacitor reaches substantially a predetermined level.

Claim 14

The combination as claimed in claim 10 wherein said third means includes first and second transistors each having a base, an emitter and a collector with the base and the collector of said second transistor being connected, the base-emitter circuit of said first transistor being connected in series additive relation with the base-emitter circuit of said second transistor to produce said output voltage which varies with substantially the logarithm of the square of said first output current.

Claim 15

The combination as claimed in claim 11 wherein said fourth means includes an output transistor having a base, an emitter and a collector, the base-emitter circuit of said output transistor being connected to said third means to be responsive to the output voltage of said third means to thereby produce said second output current.

Claim 16

The combination as claimed in claim 11 wherein said fourth means includes first and second transistors each having a base, an emitter and a collector with the basE and the collector of said first transistor being connected, and an additional means connected to said first transistor for supplying substantially a predetermined unidirectional current to the base-emitter circuit of said first transistor, the base-emitter circuit of said first transistor being connected in series circuit relation with the base-emitter circuit, the output voltage of said third means being applied across the latter series circuit to produce said second output current in the collector of said second transistor.

Claim 17

An overcurrent protective circuit for use with a three-phase alternating current circuit comprising first means adapted to be connected to all three phases of said circuit for deriving therefrom a unidirectional voltage which is substantially proportional to the highest of the three phase currents, second means connected to said first means for converting at least a portion of said unidirectional voltage to a first output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which varies with substantially the logarithm of the square of said first output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second output current which is substantially the antilogarithm of the logarithm of the square of said first output current, said second output current varying with substantially the square of the highest current in said alternating current circuit, fifth means connected to said fourth means for producing periodic output pulses of current substantially equal in magnitude to that of said second output current, a capacitor connected to said fifth means for accumulating a charge, sixth means connected to said first means and to said capacitor to be responsive to the current in said circuit for actuating said capacitor to be charged by said pulses of current when said current in the circuit increases to substantially a predetermined value and seventh means connected to said capacitor for providing an output when the charge on said capacitor reaches substantially a predetermined level.

Claim 18

An overcurrent protective circuit for use with a three-phase alternating current circuit comprising first means adapted to be connected to all three phases of said circuit for deriving therefrom a unidirectional voltage which is substantially proportional to the highest of the three phase currents, second means connected to said first means for converting at least a portion of said unidirectional voltage to a first output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which varies with substantially the logarithm of the square of said first output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second output current which is substantially the antilogarithm of the logarithm of the square of said first output current, said second output current varying with substantially the square of the highest current in said alternating current circuit, fifth means connected to said fourth means for producing periodic output pulses of current substantially equal in magnitude to that of said second output current, a capacitor connected to said fifth means for accumulating a charge, sixth means connected to said first means and to said capacitor to be responsive to the current in said circuit for actuating said capacitor to be charged by said pulses of current when said current in the circuit increases to substantially a predetermined value and seventh means connected to said capacitor for providing an output when the charge on said capacitor reaches substantially a predetermined level.

Claim 19

The combination as claimed in claim 14 wherein an additional means is connected to said third means and to said fifth means for actuating said third means and fourth means to operate only during the periodic output pulses of said fifth means.

Claim 20

The combination as claimed in claim 14 wherein said third means includes first and second transistors each having a base, an emitter and a collector with the base and the collector of said second transistor being connected, the base-emitter circuit of said first transistor being connected in series additive relation with the base-emitter circuit of said second transistor to produce said output voltage which varies with substantially the logarithm of the square of said first output current.

Claim 21

The combination as claimed in claim 16 wherein said fourth means includes an output transistor having a base, an emitter and a collector, the base-emitter circuit of said output transistor being connected to said third means to be responsive to the output voltage of said third means to thereby produce said second output current.

Claim 22

The combination as claimed in claim 16 wherein said fourth means includes first and second transistors each having a base, an emitter and a collector with the base and the collector of said first transistor being connected, and an additional means connected to said first transistor for supplying substantially a predetermined unidirectional current to the base-emitter circuit of said first transistor, the base-emitter circuit of said first transistor being connected in series circuit relation with the base-emitter circuit, the output voltage of said third means being applied across the latter series circuit to produce said second output current in the collector of said second transistor.

Claim 23

A circuit breaker comprising three sets of separable contacts, operating means for opening and closing said sets of contacts, conductors connected to each set of said contact, a plurality of current transformers disposed to obtain three output currents which are substantially proportional to the currents in said conductors, first means connected to said current transformers for deriving therefrom a unidirectional voltage which is substantially proportional to only the highest of said output currents, second means for converting said unidirectional voltage to a first unidirectional output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which varies with substantially the logarithm of the square of said first unidirectional output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second unidirectional output current which is substantially the antilogarithm of the logarithm of the square of said first unidirectional output current, said second unidirectional output current varying with substantially the square of the highest current in said conductors, fifth means connected to said fourth means for producing periodic output pulses of current substantially equal in magnitude to that of said second output current, a capacitor connected to said fifth means for accumulating a charge, sixth means connected to said first means and to said capacitor for actuating said capacitor to be charged by said pulses of current when the highest current in said conductors exceeds a predetermined value and seventh means operatively connected between said capacitor and said operating means for producing an output when the charge on said capacitor exceeds a predetermined value to actuate said operating means to open said sets of contacts.

Claim 24

A circuit breaker comprising three sets of separable contacts, operating means for opening and closing said sets of contacts, conductors connected to each set of said contact, a plurality of current transformers disposed to obtain three output currents which are substantially proportional to the currents in said conductors, first means connected to said current transformers for deriving therefrom a unidirectional voltage which is substantially proportional to only the highest of said output currents, second means for converting said unidirectional voltage to a first unidirectional output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which varies with substantially the logarithm of the square of said first unidirectional output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second unidirectional output current which is substantially the antilogarithm of the logarithm of the square of said first unidirectional output current, said second unidirectional output current varying with substantially the square of the highest current in said conductors, fifth means connected to said fourth means for producing periodic output pulses of current substantially equal in magnitude to that of said second output current, a capacitor connected to said fifth means for accumulating a charge, sixth means connected to said first means and to said capacitor for actuating said capacitor to be charged by said pulses of current when the highest current in said conductors exceeds a predetermined value and seventh means operatively connected between said capacitor and said operating means for producing an output when the charge on said capacitor exceeds a predetermined value to actuate said operating means to open said sets of contacts.

Claim 25

The combination as claimed in claim 19 wherein an additional means is connected to said third means and to said fifth means for actuating said third means and fourth means to operate only during the periodic output pulses of said fifth means.

Claim 26

The combination as claimed in claim 19 wherein said third means includes first and second transistors each having a base, an emitter and a collector with base and the collector of said second transistor being connected, the base-emitter circuit of said first transistor being connected in series additive relation with the base-emitter circuit of said second transistor to produce said output voltage which varies with substantially the logarithm of the square of said first output current.

Claim 27

The combination as claimed in claim 21 wherein said fourth means includes an output transistor having a base, an emitter and a collector, the base-emitter circuit of said output transistor being connected to said third means to be responsive to the output voltage of said third means to thereby produce said second output current.

Claim 28

The combination as claimed in claim 21 wherein said fourth means includes first and second transistors each having a base, an emitter and a collector with the base and the collector of said first transistor being connected, and an additional means connected to said first transistor for supplying substantially a predetermined unidirectional current to the base-emitter circuit of said first transistor, the base-emitter circuit of said first transistor being connected in series circuit relation with the base-emitter circuit, the output voltage of said third means being applied across the latter series circuit to produce said second output current in the collector of said second transistor.

Claim 29

A circuit breaker comprising three sets of separable contacts, operating means for opening and closing said sets of contacts, conductors connected to each set of said contact, a plurality of current transformers disposed to obtain three output currents which are substantially proportional to the currents in said conductors, first means connected to said current transformers for derIving therefrom a unidirectional voltage which is substantially proportional to only the highest of said output currents, second means for converting said unidirectional voltage to a first unidirectional output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which varies with substantially the logarithm of the square of said first unidirectional output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second unidirectional output current which is substantially the antilogarithm of the logarithm of the square of said first unidirectional output current, said second unidirectional output current varying with substantially the square of the highest current in said conductors, a capacitor connected to said fourth means for accumulating a charge, fifth means connected to said first means and to said capacitor for actuating said capacitor to be charged by said second unidirectional output current from said fourth means when the highest current in said conductors exceeds a predetermined value and sixth means operatively connected between said capacitor and said operating means for producing an output when the charge on said capacitor exceeds a predetermined value to actuate said operating means to open said sets of contacts.

Claim 30

A circuit breaker comprising three sets of separable contacts, operating means for opening and closing said sets of contacts, conductors connected to each set of said contact, a plurality of current transformers disposed to obtain three output currents which are substantially proportional to the currents in said conductors, first means connected to said current transformers for derIving therefrom a unidirectional voltage which is substantially proportional to only the highest of said output currents, second means for converting said unidirectional voltage to a first unidirectional output current which is substantially proportional to said unidirectional voltage, third means connected to said second means for producing an output voltage which varies with substantially the logarithm of the square of said first unidirectional output current, fourth means connected to said third means which is responsive to the last-mentioned voltage for producing a second unidirectional output current which is substantially the antilogarithm of the logarithm of the square of said first unidirectional output current, said second unidirectional output current varying with substantially the square of the highest current in said conductors, a capacitor connected to said fourth means for accumulating a charge, fifth means connected to said first means and to said capacitor for actuating said capacitor to be charged by said second unidirectional output current from said fourth means when the highest current in said conductors exceeds a predetermined value and sixth means operatively connected between said capacitor and said operating means for producing an output when the charge on said capacitor exceeds a predetermined value to actuate said operating means to open said sets of contacts.