Time delay device

Claim 2

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor coupled to said input and chargable by the current flowing therein, leakage resistor means normally shunting said timing capacitor for preventing the charging thereof by the current flowing to said input, normally inactive electronic circuit means coupled to said input and to said timing capacitor and responsive to an abnormal circuit condition in said system for conducting current to said resistor means to modify the voltage drop thereacross and prevent the discharge of said capacitor through said leakage resistor means upon the occurrence of said abnormal circuit condition so that said timing capacitor may begin charging.

Claim 3

In an electronic timing device having an input adapted to be connected to an electrical system, energy storage means coupled to said input, leakage resistor means normally shunting said energy storage means for preventing the charging thereoF by the current flowing to said input, overload sensing means coupled to said input and normally inactive electronic means coupled to said leakage resistor means, said overload sensing means being responsive to the current in said system to actuate said electronic circuit means for raising the voltage drop across said leakage resistor means to thereby prevent the discharge of said energy storage means therethrough when the current in said system reaches a predetermined value, whereby said energy storage means is allowed to charge up.

Claim 4

In an electronic timing device having an input adapted to be connected to an electrical system, energy storage means coupled to said input, leakage resistor means normally shunting said energy storage means for preventing the charging thereoF by the current flowing to said input, overload sensing means coupled to said input and normally inactive electronic means coupled to said leakage resistor means, said overload sensing means being responsive to the current in said system to actuate said electronic circuit means for raising the voltage drop across said leakage resistor means to thereby prevent the discharge of said energy storage means therethrough when the current in said system reaches a predetermined value, whereby said energy storage means is allowed to charge up.

Claim 5

In an electronic timing device having an input adapted to be connected to an electrical system, timing capacitor means coupled to said input, leakage resistor means normally shunting said timing capacitor for preventing the charging thereof by the current flowing to said input, circuit means including overload sensing means coupled to said input and normally inactive electronic means coupled to said leakage resistor means, said overload sensing means being responsive to the current in said system to actuate said electronic means to conduct current to said leakage resistor to raise the voltage drop thereacross to thereby prevent the discharge of said timing capacitor means therethrough when the current in said system reaches a predetermined value, whereby said energy storage means is allowed to charge up, and means for preventing current from flowing from said leakage resistor means to said timing capacitor means.

Claim 6

In an electronic timing device having an input adapted to be connected to an electrical system, timing capacitor means coupled to said input, leakage resistor means normally shunting said timing capacitor for preventing the charging thereof by the current flowing to said input, circuit means including overload sensing means coupled to said input and normally inactive electronic means coupled to said leakage resistor means, said overload sensing means being responsive to the current in said system to actuate said electronic means to conduct current to said leakage resistor to raise the voltage drop thereacross to thereby prevent the discharge of said timing capacitor means therethrough when the current in said system reaches a predetermined value, whereby said energy storage means is allowed to charge up, and means for preventing current from flowing from said leakage resistor means to said timing capacitor means.

Claim 7

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor connected to said input and chargeable by the current flowing therein, a leakage resistor shunting said timing capacitor, voltage comparison means having sensing means and reference voltage means, said voltage comparison means also having output means connected to said leakage resistor means, said voltage comparison means being actuable when the voltage at said sensing means exceeds said reference voltage to conduct current to said leakage resistor means, circuit means connecting said sensing means to said input for placing a voltage on said sensing means that is proportional to the current at said input whereby output current will flow to said leakage resistor when the current at said input exceeds a predetermined value to thereby raise its voltage to a value higher than the voltage across said timing capacitor so that the further discharge thereof is prevented, unidirectional circuit means for preventing current flow from said leakage resistor means to said timing capacitor, and output means coupled to said timing capacitor and operable when the charge thereon exceeds a predetermined value.

Claim 8

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor connected to said input and chargeable by the current flowing therein, a leakage resistor shunting said timing capacitor, voltage comparison means having sensing means and reference voltage means, said voltage comparison means also having output means connected to said leakage resistor means, said voltage comparison means being actuable when the voltage at said sensing means exceeds said reference voltage to conduct current to said leakage resistor means, circuit means connecting said sensing means to said input for placing a voltage on said sensing means that is proportional to the current at said input whereby output current will flow to said leakage resistor when the current at said input exceeds a predetermined value to thereby raise its voltage to a value higher than the voltage across said timing capacitor so that the further discharge thereof is prevented, unidirectional circuit means for preventing current flow from said leakage resistor means to said timing capacitor, and output means coupled to said timing capacitor and operable when the charge thereon exceeds a predetermined value.

Claim 9

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor connected to said input and chargeable by the current flowing therein, a leakage resistor shunting said timing capacitor, a signal responsive transistor, reference voltage means, circuit means connecting the base of said signal responsive transistor to said input for placing a potential on said base that is proportional to the current at said input, the emitter of said transistor being connected to said reference voltage means whereby collector current will flow in said transistor when the current at said input exceeds a predetermined value, normally non-conducting current responsive means connected to said leakage resistor and to the collector of said transistor so that when collector current flows therein as a result of said predetermined current at said input said current responsive circuit means will conduct current to said leakage resistor to thereby raise its voltage to a value higher than the voltage across said timing capacitor so that the further discharge thereof is prevented, and diode means for preventing current from flowing from said leakage resistor to said timing capacitor.

Claim 10

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor connected to said input and chargeable by the current flowing therein, a leakage resistor shunting said timing capacitor, a signal responsive transistor, reference voltage means, circuit means connecting the base of said signal responsive transistor to said input for placing a potential on said base that is proportional to the current at said input, the emitter of said transistor being connected to said reference voltage means whereby collector current will flow in said transistor when the current at said input exceeds a predetermined value, normally non-conducting current responsive means connected to said leakage resistor and to the collector of said transistor so that when collector current flows therein as a result of said predetermined current at said input said current responsive circuit means will conduct current to said leakage resistor to thereby raise its voltage to a value higher than the voltage across said timing capacitor so that the further discharge thereof is prevented, and diode means for preventing current from flowing from said leakage resistor to said timing capacitor.

Claim 11

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing caPacitor connected to said input and chargeable by the current flowing therein, a leakage resistor shunting said timing capacitor, triode means having a source element, a load element and a control element, reference voltage means, circuit means connecting the control element of said triode means to said input for placing a potential on said control element that is proportional to the current at said input, the source element of said triode means being connected to said reference voltage means whereby load current will flow in said load element when the current at said input exceeds a predetermined value, normally non-conducting current responsive means connected to said leakage resistor and to said load element so that when load current flows in said triode means as a result of said predetermined current at said input said current responsive means will conduct current to said leakage resistor to thereby raise its voltage to a value higher than the voltage across said timing capacitor so that the further discharge thereof is prevented, and output means coupled to said timing capacitor and operable when the charge thereon exceeds a predetermined value.

Claim 12

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing caPacitor connected to said input and chargeable by the current flowing therein, a leakage resistor shunting said timing capacitor, triode means having a source element, a load element and a control element, reference voltage means, circuit means connecting the control element of said triode means to said input for placing a potential on said control element that is proportional to the current at said input, the source element of said triode means being connected to said reference voltage means whereby load current will flow in said load element when the current at said input exceeds a predetermined value, normally non-conducting current responsive means connected to said leakage resistor and to said load element so that when load current flows in said triode means as a result of said predetermined current at said input said current responsive means will conduct current to said leakage resistor to thereby raise its voltage to a value higher than the voltage across said timing capacitor so that the further discharge thereof is prevented, and output means coupled to said timing capacitor and operable when the charge thereon exceeds a predetermined value.

Claim 13

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor coupled to said input and chargeable by the current flowing therein, leakage resistor means connected in parallel with said timing capacitor for normally shunting said charging current therearound, voltage biasing means connected to said leakage resistor means in a sense opposite to the sense of said shunted current so that the effect of the voltage drop across said leakage resistor on the potential of the junction between said leakage resistor and said timing capacitor is partially cancelled, rectifier means shunting said timing capacitor and operable to shunt around said timing capacitor any reverse current from said leakage resistor as a result of said biasing means whereby the voltage drop in said leakage resistor as a result of said leakage current does not produce a difference in potential across said timing capacitor, circuit means coupled to said input and responsive to the current in said system for preventing the discharge of said capacitor through said leakage resistor means when the current in said system reaches a predetermined value.

Claim 14

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor coupled to said input and chargeable by the current flowing therein, leakage resistor means connected in parallel with said timing capacitor for normally shunting said charging current therearound, voltage biasing means connected to said leakage resistor means in a sense opposite to the sense of said shunted current so that the effect of the voltage drop across said leakage resistor on the potential of the junction between said leakage resistor and said timing capacitor is partially cancelled, rectifier means shunting said timing capacitor and operable to shunt around said timing capacitor any reverse current from said leakage resistor as a result of said biasing means whereby the voltage drop in said leakage resistor as a result of said leakage current does not produce a difference in potential across said timing capacitor, circuit means coupled to said input and responsive to the current in said system for preventing the discharge of said capacitor through said leakage resistor means when the current in said system reaches a predetermined value.

Claim 15

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor connected to said input and chargeable by the current flowing therein, a leakage resistor connected in parallel with said timing capacitor for shunting said charging current therearound; means coupled to said timing capacitor and to said leakage resistor means for cancelling the effect of the shunted current produced voltage drop across said leakage resistor on said timing capacitor means whereby the voltage drop in said leakage resistor does not produce a potential difference across said timing capacitor, voltage comparison means having sensing means and reference voltage means, said voltage comparison means also including output means connected to said leakage resistor means said voltage comparison means being actuable when the voltage at said sensing means exceeds said reference voltage to conduct current to said leakage resistor means, circuit means connecting said sensing means to said input for placing a voltage on said sensing means that is proportional to the current at said input whereby output current will flow to said leakage resistor to thereby raise its voltage to a value higher than the voltage across said timing capacitor so that the further discharge thereof is prevented.

Claim 16

An electronic timing device comprising an input adapted to be connected to an electrical system, a timing capacitor connected to said input and chargeable by the current flowing therein, a leakage resistor connected in parallel with said timing capacitor for shunting said charging current therearound; means coupled to said timing capacitor and to said leakage resistor means for cancelling the effect of the shunted current produced voltage drop across said leakage resistor on said timing capacitor means whereby the voltage drop in said leakage resistor does not produce a potential difference across said timing capacitor, voltage comparison means having sensing means and reference voltage means, said voltage comparison means also including output means connected to said leakage resistor means said voltage comparison means being actuable when the voltage at said sensing means exceeds said reference voltage to conduct current to said leakage resistor means, circuit means connecting said sensing means to said input for placing a voltage on said sensing means that is proportional to the current at said input whereby output current will flow to said leakage resistor to thereby raise its voltage to a value higher than the voltage across said timing capacitor so that the further discharge thereof is prevented.

Claim 17

In an electronic timing device the combination of an input adapted to be connected to an electrical system, timing capacitor means connected to said input and chargeable by the current flowing therein, an impedance in a parallel circuit with respect to said timing capacitor means for shunting a portion of said current around said timing capacitor said paralLel circuit including means for holding said shunted current to a predetermined value, leakage means connected to said capacitor and normally preventing the charging thereof, said energy leakage means including circuit means connected to said input and responsive to a predetermined current in said system for preventing the leakage of said current means through said leakage means so that said timing capacitor means beings charging upon the occurrence of said predetermined current.

Claim 18

In an electronic timing device the combination of an input adapted to be connected to an electrical system, timing capacitor means connected to said input and chargeable by the current flowing therein, an impedance in a parallel circuit with respect to said timing capacitor means for shunting a portion of said current around said timing capacitor said paralLel circuit including means for holding said shunted current to a predetermined value, leakage means connected to said capacitor and normally preventing the charging thereof, said energy leakage means including circuit means connected to said input and responsive to a predetermined current in said system for preventing the leakage of said current means through said leakage means so that said timing capacitor means beings charging upon the occurrence of said predetermined current.

Claim 19

In an electronic timing device the combination of a pair of input terminals, a first charging resistor having one end connected to one of said input terminals, a second charging resistor and a transistor, said second resistor and the emitter-base circuit of said transistor being connected in parallel with said first charging resistor, a first energy storage means between the other end of said first resistor and the other input terminal, a second energy storage means connected between the collector of said transistor and said other input terminal, whereby each of said energy storage means is chargeable by the current flowing in its associated resistor, energy responsive means coupled to said first energy storage means and responsive to the energy stored therein for actuation when the energy on said first energy storage means reaches a predetermined value, said second energy storage means being connected to said energy responsive means for supplying operating energy thereto.

Claim 20

In an electronic timing device the combination of a pair of input terminals, a first charging resistor having one end connected to one of said input terminals, a second charging resistor and a transistor, said second resistor and the emitter-base circuit of said transistor being connected in parallel with said first charging resistor, a first energy storage means between the other end of said first resistor and the other input terminal, a second energy storage means connected between the collector of said transistor and said other input terminal, whereby each of said energy storage means is chargeable by the current flowing in its associated resistor, energy responsive means coupled to said first energy storage means and responsive to the energy stored therein for actuation when the energy on said first energy storage means reaches a predetermined value, said second energy storage means being connected to said energy responsive means for supplying operating energy thereto.

Claim 21

In a device for protecting an electrical system, the combination of a pair of input terminals, a current transformer and a rectifier connecting said input terminals to said system, a first charging resistor having one end connected to one of said input terminals, a second charging resistor and a transistor, said second resistor and the emitter-base circuit of said transistor being connected in parallel with said first charging resistor, energy storage means connected between the collector of said transistor and the other input terminal, whereby said energy storage means is chargeable by a predetermined portion of the current flowing at said input terminals.

Claim 22

In a device for protecting an electrical system, the combination of a pair of input terminals, a current transformer and a rectifier connecting said input terminals to said system, a first charging resistor having one end connected to one of said input terminals, a second charging resistor and a transistor, said second resistor and the emitter-base circuit of said transistor being connected in parallel with said first charging resistor, energy storage means connected between the collector of said transistor and the other input terminal, whereby said energy storage means is chargeable by a predetermined portion of the current flowing at said input terminals.

Claim 23

An electronic timing device comprising a pair of input terminals, a first current dividing resistor having one end connected to one of said input terminals, a second current dividing resistor and a charging transistor, said second current dividing resistor and the emitter-base circuit of said charging transistor being connected in parallel with said first current dividing resistor, a timing capacitor connected between the collector of said coupling transistor and said other input terminal and adapted to be charged by the current flowing therein, a power capacitor connected to the other end of said first current dividing resistor, and voltage responsive means connected to said timing capacitor for actuation when the charge on said timing capacitor reaches a predetermined value, said power capacitor means being connected to said voltage responsive means for supplying operating energy thereto.

Claim 24

An electronic timing device comprising a pair of input terminals, a first current dividing resistor having one end connected to one of said input terminals, a second current dividing resistor and a charging transistor, said second current dividing resistor and the emitter-base circuit of said charging transistor being connected in parallel with said first current dividing resistor, a timing capacitor connected between the collector of said coupling transistor and said other input terminal and adapted to be charged by the current flowing therein, a power capacitor connected to the other end of said first current dividing resistor, and voltage responsive means connected to said timing capacitor for actuation when the charge on said timing capacitor reaches a predetermined value, said power capacitor means being connected to said voltage responsive means for supplying operating energy thereto.

Claim 25

A circuit interrupting device for protecting an electrical system from overload currents, switch means for interrupting the current in said system, timing capacitor means coupled to said system, first impedance means coupled to said timing capacitor means for controlling the charging rate thereof as a function of the magnitude of the current in said system, second impedance means in circuit with said timing capacitor means for controlling the charging rate thereof independently of the magnitude of the current in said system, third impedance means coupled to said timing capacitor means for normally holding the same in a discharged condition, overload responsive means coupled to said system and operable when the current therein exceeds a predetermined value to conduct current to said third impedance means so as to raise the voltage drop thereacross and to prevent the further discharge of said capacitor means therethrough so that said charging capacitor may beGin charging, and uni-directional current means for preventing current flow from said third impedance means to said timing capacitor means, and output means coupled to said capacitor means and operable to open said switch means when the charge thereon reaches a predetermined value.

Claim 26

A circuit interrupting device for protecting an electrical system from overload currents, switch means for interrupting the current in said system, timing capacitor means coupled to said system, first impedance means coupled to said timing capacitor means for controlling the charging rate thereof as a function of the magnitude of the current in said system, second impedance means in circuit with said timing capacitor means for controlling the charging rate thereof independently of the magnitude of the current in said system, third impedance means coupled to said timing capacitor means for normally holding the same in a discharged condition, overload responsive means coupled to said system and operable when the current therein exceeds a predetermined value to conduct current to said third impedance means so as to raise the voltage drop thereacross and to prevent the further discharge of said capacitor means therethrough so that said charging capacitor may beGin charging, and uni-directional current means for preventing current flow from said third impedance means to said timing capacitor means, and output means coupled to said capacitor means and operable to open said switch means when the charge thereon reaches a predetermined value.

Claim 27

A circuit interrupter for protecting an electrical system from overload currents, switch means in circuit with said system for interrupting the current flow therein, timing capacitor means coupled to said system, first resistance means in series circuit relation with said timing capacitor means for controlling the charging rate thereof as a function of the magnitude of the current in said system, second resistance means in parallel circuit relation with said timing capacitor means for controlling the charging rate thereof independently of the magnitude of the current in said system, third resistance means connected in parallel circuit relation with said timing capacitor means for normally holding the same in a discharged condition, overload responsive means coupled to said system and responsive to a predetermined current therein for conducting current to said third resistance means to raise the voltage drop thereacross so that said timing capacitor is prevented from discharging therethrough, whereby said timing capacitor begins charging when the current in said system reaches a predetermined value, uni-directional current means for preventing current from flowing from said third resistance means to said timing capacitor means, and output means coupled to said timing capacitor means and operable when the charge thereon reaches a predetermined value for opening said switch means.

Claim 28

A circuit interrupter for protecting an electrical system from overload currents, switch means in circuit with said system for interrupting the current flow therein, timing capacitor means coupled to said system, first resistance means in series circuit relation with said timing capacitor means for controlling the charging rate thereof as a function of the magnitude of the current in said system, second resistance means in parallel circuit relation with said timing capacitor means for controlling the charging rate thereof independently of the magnitude of the current in said system, third resistance means connected in parallel circuit relation with said timing capacitor means for normally holding the same in a discharged condition, overload responsive means coupled to said system and responsive to a predetermined current therein for conducting current to said third resistance means to raise the voltage drop thereacross so that said timing capacitor is prevented from discharging therethrough, whereby said timing capacitor begins charging when the current in said system reaches a predetermined value, uni-directional current means for preventing current from flowing from said third resistance means to said timing capacitor means, and output means coupled to said timing capacitor means and operable when the charge thereon reaches a predetermined value for opening said switch means.

Claim 29

In an electronic timing device having an input connected to an electric system, timing capacitor means, circuit means coupled to said input for charging said timing capacitor means by a current functionally related to the current in said input, leakage means normally shunting said timing capacitor means for preventing the charging thereof, an energy source, abnormal condition responsive means coupled to said input, switching means coupled to said leakage means and to said energy source, said overload responsive means being operative upon the occurrence of an abnormal circuit condition to actuate said switching means to couple said leakage means to said energy source for modifying the potential of said leakage means to thereby prevent the discharge of said timing capacitor means therethrough whereby said timing capacitor means is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge on said timing capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage means to said timing capacitor means.

Claim 30

In an electronic timing device having an input connected to an electric system, timing capacitor means, circuit means coupled to said input for charging said timing capacitor means by a current functionally related to the current in said input, leakage means normally shunting said timing capacitor means for preventing the charging thereof, an energy source, abnormal condition responsive means coupled to said input, switching means coupled to said leakage means and to said energy source, said overload responsive means being operative upon the occurrence of an abnormal circuit condition to actuate said switching means to couple said leakage means to said energy source for modifying the potential of said leakage means to thereby prevent the discharge of said timing capacitor means therethrough whereby said timing capacitor means is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge on said timing capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage means to said timing capacitor means.

Claim 31

In a circuit interrupter for protecting an electrical system, an electronic timing device having an input coupled to said system for deriving an electrical signal functionally related to the current therein, an energy source, energy storage means, electronic circuit means having a control element connected to said energy source, an output element connected to said energy storage means and an input element connected to said input, said electronic circuit means being characterized in that current will flow from said output element when the ratio of the output element potential to the control element potential is within a predetermined range of values, whereby the maximum energy potential applied to said energy storage means cannot exceed a predetermined value, and energy responsive means coupled to said energy storage means and responsive when the energy thereon reaches a predetermined value.

Claim 32

In a circuit interrupter for protecting an electrical system, an electronic timing device having an input coupled to said system for deriving an electrical signal functionally related to the current therein, an energy source, energy storage means, electronic circuit means having a control element connected to said energy source, an output element connected to said energy storage means and an input element connected to said input, said electronic circuit means being characterized in that current will flow from said output element when the ratio of the output element potential to the control element potential is within a predetermined range of values, whereby the maximum energy potential applied to said energy storage means cannot exceed a predetermined value, and energy responsive means coupled to said energy storage means and responsive when the energy thereon reaches a predetermined value.

Claim 33

A circuit interrupter for protecting an electrical system, an electronic timing device having an input coupled to said system for deriving an electrical signal functionally related to the current therein, an energy source, a transistor, energy storage means, the emitter and collector of said transistor being connected to said input for receiving said signal, the emitter and base of said transistor connecting said energy storage means to said energy source whereby the maximum energy potential applied to said energy storage means cannot exceed the potential energy of said source, and energy responsive means coupled to said energy storage means and responsive when the charge thereon reaches a predetermined value.

Claim 34

A circuit interrupter for protecting an electrical system, an electronic timing device having an input coupled to said system for deriving an electrical signal functionally related to the current therein, an energy source, a transistor, energy storage means, the emitter and collector of said transistor being connected to said input for receiving said signal, the emitter and base of said transistor connecting said energy storage means to said energy source whereby the maximum energy potential applied to said energy storage means cannot exceed the potential energy of said source, and energy responsive means coupled to said energy storage means and responsive when the charge thereon reaches a predetermined value.

Claim 35

In an electronic timing device the combination of a pair of input terminals, a first resistance having one end connected to one of said input terminals, a second resistance and a transistor, said second resistance and the emitter base circuit of said transistor being connected in parallel with said first resistance, a voltage source connected to the other end of said first resistance, energy storage means connected to the collector of said transistor for charging by the current flowing in said second resistance, whereby the voltage applied to said energy storage means cannot exceed the voltage of said energy source, and energy responsive means coupled to said energy storage means and responsive when the energy stored therein reaches a predetermined value.

Claim 36

In an electronic timing device the combination of a pair of input terminals, a first resistance having one end connected to one of said input terminals, a second resistance and a transistor, said second resistance and the emitter base circuit of said transistor being connected in parallel with said first resistance, a voltage source connected to the other end of said first resistance, energy storage means connected to the collector of said transistor for charging by the current flowing in said second resistance, whereby the voltage applied to said energy storage means cannot exceed the voltage of said energy source, and energy responsive means coupled to said energy storage means and responsive when the energy stored therein reaches a predetermined value.

Claim 37

In an electronic timing device having an input connected to an electrical system, timing capacitor means coupled to said input, leakage resistor means normally shunting said timing capacitor means for preventing the charging thereof by the current flowing to said input, an energy source, circuit means coupled to said input and to said leakage resistor means and including abnormal condition responsive means and switching means having a control element connected to said abnormal condition responsive means and output means operative to connect said resistor means to said energy source, said overload responsive means being operative upon the occurrence of an abnormal circuit condition to provide an actuating signal to said control element so that said resistor means is connected to said energy source for modifying the potential thereof and prevent discharge of said timing capacitor therethrough, whereby said timing capacitor means is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge on said capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage resistor means to said timing capacitor means.

Claim 38

In an electronic timing device having an input connected to an electrical system, timing capacitor means coupled to said input, leakage resistor means normally shunting said timing capacitor means for preventing the charging thereof by the current flowing to said input, an energy source, circuit means coupled to said input and to said leakage resistor means and including abnormal condition responsive means and switching means having a control element connected to said abnormal condition responsive means and output means operative to connect said resistor means to said energy source, said overload responsive means being operative upon the occurrence of an abnormal circuit condition to provide an actuating signal to said control element so that said resistor means is connected to said energy source for modifying the potential thereof and prevent discharge of said timing capacitor therethrough, whereby said timing capacitor means is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge on said capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage resistor means to said timing capacitor means.

Claim 39

In an electronic timing device having an input connected to an electrical system, timing capacitor means coupled to said input, leakage resistor means normally shunting said timing capacitor means for preventing the charging thereof by the current flowing to said input, abnormal condition responsive means coupled to said input, electronic circuit means coupled to said leakage resistor means, said overload responsive means being operative upon the occurrence of an abnormal circuit condition to cause said electronic circuit means to conduct current to said leakage resistor for modifying the potential thereof and prevent discharge of said timing capacitor means therethrough, whereby said capacitor means is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge on said capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage resistor means to said timing capacitor means.

Claim 40

In an electronic timing device having an input connected to an electrical system, timing capacitor means coupled to said input, leakage resistor means normally shunting said timing capacitor means for preventing the charging thereof by the current flowing to said input, abnormal condition responsive means coupled to said input, electronic circuit means coupled to said leakage resistor means, said overload responsive means being operative upon the occurrence of an abnormal circuit condition to cause said electronic circuit means to conduct current to said leakage resistor for modifying the potential thereof and prevent discharge of said timing capacitor means therethrough, whereby said capacitor means is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge on said capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage resistor means to said timing capacitor means.

Claim 41

In an electronic timing device having an input connected to an electrical system, timing capacitor means coupled to said input, leakage resistor means normally shunting said timing capacitor means for preventing the charging thereof by the current flowing to said input, abnormal condition responsive means coupled to said input, transistor means having a base connected to said abnormal condition responsive means and an emitter-collector circuit connected to said leakage resistor, said overload responsive means being operative upon the ocCurrence of an abnormal circuit condition to cause said transistor to conduct current to said leakage resistor for modifying the voltage drop thereacross and prevent the discharge of said timing capacitor means therethrough, whereby said timing capacitor means is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge in said capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage resistor means to said timing capacitor means.

Claim 42

In an electronic timing device having an input connected to an electrical system, timing capacitor means coupled to said input, leakage resistor means normally shunting said timing capacitor means for preventing the charging thereof by the current flowing to said input, abnormal condition responsive means coupled to said input, transistor means having a base connected to said abnormal condition responsive means and an emitter-collector circuit connected to said leakage resistor, said overload responsive means being operative upon the ocCurrence of an abnormal circuit condition to cause said transistor to conduct current to said leakage resistor for modifying the voltage drop thereacross and prevent the discharge of said timing capacitor means therethrough, whereby said timing capacitor means is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge in said capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage resistor means to said timing capacitor means.

Claim 43

In a circuit interrupter for protecting an electrical system, an electronic timing device having an input coupled to said system for deriving an electrical signal functionally related to the current therein, an energy source, energy storage means, electronic circuit means having a control element connected to said energy source, an output element connected to said energy storage means and an input element connected to said input, said electronic circuit means being operative to conduct input current to said output when the ratio of the output element potential to the control element potential is less than a predetermined value, whereby said energy source is chargeable by a current functionally related to said signal until the potential thereof reaches a predetermined value, leakage impedance means normally shunting said energy storage means to prevent the charging thereof, abnormal condition responsive means coupled to said input and to said impedance means and operative to couple said impedance means to said energy source upon the occurrence of an abnormal circuit condition so that potential of said impedance means is modified to prevent the further discharge of said energy storage means therethrough, unidirectional current means for preventing the flow of current from said impedance means to said energy storage means, and energy responsive means coupled to said energy storage means and responsive when the energy thereon reaches a predetermined value.

Claim 44

In a circuit interrupter for protecting an electrical system, an electronic timing device having an input coupled to said system for deriving an electrical signal functionally related to the current therein, an energy source, energy storage means, electronic circuit means having a control element connected to said energy source, an output element connected to said energy storage means and an input element connected to said input, said electronic circuit means being operative to conduct input current to said output when the ratio of the output element potential to the control element potential is less than a predetermined value, whereby said energy source is chargeable by a current functionally related to said signal until the potential thereof reaches a predetermined value, leakage impedance means normally shunting said energy storage means to prevent the charging thereof, abnormal condition responsive means coupled to said input and to said impedance means and operative to couple said impedance means to said energy source upon the occurrence of an abnormal circuit condition so that potential of said impedance means is modified to prevent the further discharge of said energy storage means therethrough, unidirectional current means for preventing the flow of current from said impedance means to said energy storage means, and energy responsive means coupled to said energy storage means and responsive when the energy thereon reaches a predetermined value.

Claim 45

A circuit interrupter for protecting an electrical system, an electronic timing device having an input coupled to said system for deriving an electrical system functionally related to the current therein, an energy source, a timing capacitor, a transistor, the emitter and base of said transistor being connected to said input for receiving said signal, the collector and base of said transister connecting said energy storage means to said energy source whereby the maximum energy potential applied to said energy storage means cannot exceed the potential of said energy source, leakage resistor means normally shunting said timing capacitor for preventing the charging thereof, abnormal condition responsive means connected to said input, switching means coupled to said abnormal condition responsive means and to said leakage resistor means and to said energy source, said overload responsive means being operative upon the occurrence of an abnormal circuit condition to provide an actuating signal to said switching means so that said leakage resistor means is connected to said energy source, for modifying the potential thereof and prevent the discharge of said timing capacitor therethrough, whereby said timing capacitor is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge on said capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage resistor means to said capacitor means.

Claim 46

A circuit interrupter for protecting an electrical system, an electronic timing device having an input coupled to said system for deriving an electrical system functionally related to the current therein, an energy source, a timing capacitor, a transistor, the emitter and base of said transistor being connected to said input for receiving said signal, the collector and base of said transister connecting said energy storage means to said energy source whereby the maximum energy potential applied to said energy storage means cannot exceed the potential of said energy source, leakage resistor means normally shunting said timing capacitor for preventing the charging thereof, abnormal condition responsive means connected to said input, switching means coupled to said abnormal condition responsive means and to said leakage resistor means and to said energy source, said overload responsive means being operative upon the occurrence of an abnormal circuit condition to provide an actuating signal to said switching means so that said leakage resistor means is connected to said energy source, for modifying the potential thereof and prevent the discharge of said timing capacitor therethrough, whereby said timing capacitor is allowed to charge up, output means coupled to said timing capacitor means and operative to interrupt said system when the charge on said capacitor means reaches a predetermined level, and unidirectional current means for preventing current flow from said leakage resistor means to said capacitor means.

Claim 47

In a protective relay assembly, a pair of terminals, means for deriving from current supplied to the pair of terminals a first direct voltage having a magnitude dependent on the magnitude of current flowing through the pair of terminals over a substantial range of variation of the magnitude of said current, means for deriving from current supplied to said pair of terminals a second direct voltage, having a magnitude which is substantially constant over said range of variation, a capacitor, circuit means connecting the capacitor for energization in accordance with the first direct voltage, said circuit means including substantial resistance whereby the circuit means and capacitor provide a time-delay circuit, controllable disabling means rendering said capacitor ineffective for receiving a charge through said circuit means, effectuating means responsive to a predetermined relation between the first and second direct voltages for controlling the disabling means to condition the capacitor to receive charge from said circuit means and translating means responsive to the voltage across said capacitor.

Claim 48

In a protective relay assembly, a pair of terminals, means for deriving from current supplied to the pair of terminals a first direct voltage having a magnitude dependent on the magnitude of current flowing through the pair of terminals over a substantial range of variation of the magnitude of said current, means for deriving from current supplied to said pair of terminals a second direct voltage, having a magnitude which is substantially constant over said range of variation, a capacitor, circuit means connecting the capacitor for energization in accordance with the first direct voltage, said circuit means including substantial resistance whereby the circuit means and capacitor provide a time-delay circuit, controllable disabling means rendering said capacitor ineffective for receiving a charge through said circuit means, effectuating means responsive to a predetermined relation between the first and second direct voltages for controlling the disabling means to condition the capacitor to receive charge from said circuit means and translating means responsive to the voltage across said capacitor.

Claim 49

For use in protecting current distribution networks static overcurrent relay means responsive to overcurrent conditions for operating circuit protective devices after a predetermined time period and before the network is damaged comprising first means for generating a DC voltage representative of the current being monitored in said network; second means coupled to said first means for generating a predetermined voltage level after a predetermined time delay; third means coupled to said first means and normally inhibiting the operation of said second means until the output voltage level of said first means achieves a predetermined magnitude; constant voltage reference means coupled to the output of said first means for establishing a second predetermined threshold level; fourth voltage-sensitive switch means coupled to said second means and said constant voltage reference means for energizing a circuit protective device when the output voltage of said second means achieves said second predetermined threshold level.

Claim 50

For use in protecting current distribution networks static overcurrent relay means responsive to overcurrent conditions for operating circuit protective devices after a predetermined time period and before the network is damaged comprising first means for generating a DC voltage representative of the current being monitored in said network; second means coupled to said first means for generating a predetermined voltage level after a predetermined time delay; third means coupled to said first means and normally inhibiting the operation of said second means until the output voltage level of said first means achieves a predetermined magnitude; constant voltage reference means coupled to the output of said first means for establishing a second predetermined threshold level; fourth voltage-sensitive switch means coupled to said second means and said constant voltage reference means for energizing a circuit protective device when the output voltage of said second means achieves said second predetermined threshold level.

Claim 51

The device of claim 25 wherein said first means is comprised of current transformer means; and full wave rectification means connected across the output of said current transformer means for generating said DC voltage.

Claim 52

The device of claim 25 wherein said constant voltage reference means is comprised of a series connected zener diode and resistor coupled between the output of said first means and ground potential; the common terminal between said zener diode and resistor being coupled to said fourth means.

Claim 53

The device of claim 27 wherein said fourth means is comprised of transistor means having first, second and third electrodes, respectively, coupled to said constant reference voltage means common terminal, the output of said second means, and said first means.