Overvoltage protective circuit for constant voltage-current crossover network

Claim 2

An overvoltage protective circuit for a direct current power supply comprising a direct current power source having a pair of output terminals, a constant current source, voltage comparator means, variable resistance means connected in series with one output terminal of said power source and an input terminal of said voltage comparator means, the other input terminal of said comparator means connected to the other output terminal of said power source, said constant current source connected to provide a constant voltage drop across said resistance means independent of the output voltage of said power source, short circuit means connected across the output terminals of said power source and adapted to actuate in response to an overvoltage signal, means for monitoring the voltage developed across said resistance means, means for adjusting said resistance means to a predetermined value as determined by said monitoring means, said comparator means adapted to provide an overvoltage signal when the voltage of said direct current power source equals said predetermined value, and means for connecting said overvoltage signal to actuate said short circuit means.

Claim 3

An overvoltage protective circuit for a direct current power supply comprising a pair of input terminals for connection to a source of direct current, a pair of load terminals for connecting a load to be supplied with regulated voltage, a voltage regulator device connected in series between an input terminal and one load terminal, a voltage-sensing circuit adapted to change the resistance of said regulator device in response to changes in output voltage at said load terminals, constant current means and resistance means connected in circuit with said load terminals to provide a reference voltage across said resistance means independent of voltage across said load terminals, voltage comparator means fed by said reference voltage and said output voltage at said load terminals, said comparator means adapted to provide a control signal when said output voltage equals said reference voltage, short circuit means connected across said load terminals and adapted to actuate in response to said contRol signal to short circuit the output voltage at said load terminals, means to increase the resistance of said regulator device to prevent the flow of current from said direct current supply to said load terminals in response to said control signal, and means for adjusting said reference voltage to set the overvoltage actuation level independent of adjustment of said output voltage.

Claim 4

An overvoltage protective circuit for a direct current power supply comprising a pair of input terminals for connection to a source of direct current, a pair of load terminals for connecting a load to be supplied with regulated voltage, a voltage regulator device connected in series between an input terminal and one load terminal, a voltage-sensing circuit adapted to change the resistance of said regulator device in response to changes in output voltage at said load terminals, constant current means and resistance means connected in circuit with said load terminals to provide a reference voltage across said resistance means independent of voltage across said load terminals, voltage comparator means fed by said reference voltage and said output voltage at said load terminals, said comparator means adapted to provide a control signal when said output voltage equals said reference voltage, short circuit means connected across said load terminals and adapted to actuate in response to said contRol signal to short circuit the output voltage at said load terminals, means to increase the resistance of said regulator device to prevent the flow of current from said direct current supply to said load terminals in response to said control signal, and means for adjusting said reference voltage to set the overvoltage actuation level independent of adjustment of said output voltage.

Claim 5

A protective circuit for preventing the output voltage of a direct current power supply from exceeding a preset value comprising a pair of input terminals for connection to a direct current power supply, a constant current source, resistance means connected in series with said constant current source and said input terminals to produce a reference voltage across said resistance means independently of the output voltage of said power supply, means for setting said reference voltage to a predetermined value monitored by a visual indicating device, means for comparing said value of said reference voltage with the output voltage of said power supply, said comparator means providing a control signal when said output voltage becomes equal to said reference voltage, and short circuit means connected across the output of said power supply and adapted to actuate in response to said control signal.

Claim 6

A protective circuit for preventing the output voltage of a direct current power supply from exceeding a preset value comprising a pair of input terminals for connection to a direct current power supply, a constant current source, resistance means connected in series with said constant current source and said input terminals to produce a reference voltage across said resistance means independently of the output voltage of said power supply, means for setting said reference voltage to a predetermined value monitored by a visual indicating device, means for comparing said value of said reference voltage with the output voltage of said power supply, said comparator means providing a control signal when said output voltage becomes equal to said reference voltage, and short circuit means connected across the output of said power supply and adapted to actuate in response to said control signal.

Claim 7

A protective circuit for a direct current power supply as set forth in claim 3 in which the short circuit means includes a silicon control rectifier.

Claim 8

A protective circuit for preventing the output voltage of a direct current power supply from exceeding a preset value comprising a pair of input terminals for connection to a direct current power supply, a constant current source, resistance means connected in circuit with said constant current source and said input terminals to produce a reference voltage across said resistance means independently of the output voltage of said power supply, means for monitoring said reference voltage, means for comparing said reference voltage with the output voltage of said power supply, said comparator means providing a control signal when said output voltage equals said reference voltage, short circuit means connected across the output of said power supply and adapted to actuate in response to said control signal, and means for adjusting the value of said reference voltage to provide a desired actuation level for said short circuit means as provided by said monitoring means.

Claim 9

A protective circuit for preventing the output voltage of a direct current power supply from exceeding a preset value comprising a pair of input terminals for connection to a direct current power supply, a constant current source, resistance means connected in circuit with said constant current source and said input terminals to produce a reference voltage across said resistance means independently of the output voltage of said power supply, means for monitoring said reference voltage, means for comparing said reference voltage with the output voltage of said power supply, said comparator means providing a control signal when said output voltage equals said reference voltage, short circuit means connected across the output of said power supply and adapted to actuate in response to said control signal, and means for adjusting the value of said reference voltage to provide a desired actuation level for said short circuit means as provided by said monitoring means.

Claim 10

An overvoltage protective circuit for use with a direct current power supply comprising constant current means and resistance means connected in circuit with the output of said power supply to provide a predetermined reference voltage across said resistance means, means for monitoring and selecting the value of said reference voltage independently of the output of said power supply, comparator means for comparing said selected voltage with the output voltage of said power supply, said comparator means adapted to provide an overvoltage signal when the output voltage equals the value of said selected voltage, and a crowbar circuit for disabling the output voltage of said power supply in response to said overvoltage signal.

Claim 11

An overvoltage protective circuit for use with a direct current power supply comprising constant current means and resistance means connected in circuit with the output of said power supply to provide a predetermined reference voltage across said resistance means, means for monitoring and selecting the value of said reference voltage independently of the output of said power supply, comparator means for comparing said selected voltage with the output voltage of said power supply, said comparator means adapted to provide an overvoltage signal when the output voltage equals the value of said selected voltage, and a crowbar circuit for disabling the output voltage of said power supply in response to said overvoltage signal.

Claim 12

An overvoltage protective circuit as set forth in claim 1 which includes means to actuate a current overload device in the output circuit of said power supply to prevent delivery of power supply current to said short circuit means in response to said overvoltage signal.

Claim 13

A regulated power supply comprising a regulating device connected between the input and output circuits of the power supply, a sensing amplifier circuit operative to produce voltage error signals representative of variations in output potential, means for coupling said voltage error signals to vary the impedance of said regulating device, a series sense impedance connected in series with the input and output circuits of said power supply, an overvoltage protective circuit including resistance means, means for producing a predetermined reference voltage across said resistance means independently of the output voltage of said power supply, means for monitoring said reference voltage, means for comparing the value of said reference voltage with the output voltage of said power supply, said comparator means adapted to provide a control signal when the output voltage equals the value of said reference voltage, a crowbar circuit connected across the output of said power supply for disabling the output voltage in response to said control signal, channeling amplifier means responsive to the output of said comparator means and to current error signals representative of variations in current through said series sense impedance to vary the conductivity of said regulating device, and means for adjusting the value of said reference voltage to provide a desired actuation level for said crowbar circuit independent of any output voltage variation as provided by said monitoring means without requiring a change in output voltage level.

Claim 14

A regulated power supply comprising a regulating device connected between the input and output circuits of the power supply, a sensing amplifier circuit operative to produce voltage error signals representative of variations in output potential, means for coupling said voltage error signals to vary the impedance of said regulating device, a series sense impedance connected in series with the input and output circuits of said power supply, an overvoltage protective circuit including resistance means, means for producing a predetermined reference voltage across said resistance means independently of the output voltage of said power supply, means for monitoring said reference voltage, means for comparing the value of said reference voltage with the output voltage of said power supply, said comparator means adapted to provide a control signal when the output voltage equals the value of said reference voltage, a crowbar circuit connected across the output of said power supply for disabling the output voltage in response to said control signal, channeling amplifier means responsive to the output of said comparator means and to current error signals representative of variations in current through said series sense impedance to vary the conductivity of said regulating device, and means for adjusting the value of said reference voltage to provide a desired actuation level for said crowbar circuit independent of any output voltage variation as provided by said monitoring means without requiring a change in output voltage level.

Claim 15

A voltage protective circuit for a power supply comprising a pair of input and output terminals, a source of direct current connected to said input terminals, a voltage-current regulator circuit which includes series-regulating means connected between an input and output terminal of said power supply, a current-sensing resistance, a voltage-sensing circuit coupled to a load circuit and said output terminals, a differential amplifier coupled from the voltage-sensing circuit to an input of said series-regulating means, said current-sensing resistance connected in series between an input terminal and an output terminal of said power supply, said current-sensing resistance providing an overvoltage control signal in response to current flow through said sensing resistance, means for coupling the control signal from said sensing resistance to said series-regulating means, a crowbar shorting device connected across said load circuit and adapted to conduct and short circuit said load circuit in response to a trigger signal, a source of reference voltage adapted to set the trip level of said crowbar device independently of the output voltage produced across said load circuit, means for monitoring said reference voltage, means for providing a trigger signal when said output voltage equals said reference voltage, means for applying said trigger signal to said crowbar shorting device, means for adjusting said reference voltage to a predetermined level of actuation for said trigger signal as provided by said monitoring means, and means in response to said trigger signal connected to prevent conduction of said series-regulating means, thereby disabling the flow of current from said source to said crowbar device.

Claim 16

A voltage protective circuit for a power supply comprising a pair of input and output terminals, a source of direct current connected to said input terminals, a voltage-current regulator circuit which includes series-regulating means connected between an input and output terminal of said power supply, a current-sensing resistance, a voltage-sensing circuit coupled to a load circuit and said output terminals, a differential amplifier coupled from the voltage-sensing circuit to an input of said series-regulating means, said current-sensing resistance connected in series between an input terminal and an output terminal of said power supply, said current-sensing resistance providing an overvoltage control signal in response to current flow through said sensing resistance, means for coupling the control signal from said sensing resistance to said series-regulating means, a crowbar shorting device connected across said load circuit and adapted to conduct and short circuit said load circuit in response to a trigger signal, a source of reference voltage adapted to set the trip level of said crowbar device independently of the output voltage produced across said load circuit, means for monitoring said reference voltage, means for providing a trigger signal when said output voltage equals said reference voltage, means for applying said trigger signal to said crowbar shorting device, means for adjusting said reference voltage to a predetermined level of actuation for said trigger signal as provided by said monitoring means, and means in response to said trigger signal connected to prevent conduction of said series-regulating means, thereby disabling the flow of current from said source to said crowbar device.

Claim 17

A voltage protective circuit for preventing the output voltage from exceeding a preset trip level in a direct current power supply which includes series-regulating means connected between the input and output of said power supply comprising means for providing a constant current source, resistance means connected in circuit with said constant current source and the input of said power supply to produce a reference voltage across said resistance means independently of the output voltage of said power supply, means for monitoring and selecting said reference voltage to a desired overvoltage trip level in excess of the present output level, said overvoltage trip level being monitored by an indicating device, means for comparing said adjusted reference voltage with said output voltage of said power supply to provide a control signal when said output voltage equals said reference voltage, crowbar short circuit means connected across the output of said power supply adapted to actuate at said trip level in response to said control signal, and means in response to said control signal to bias said series-regulating means to prevent delivery of current from the input of said power supply to said crowbar short circuit means.

Claim 18

A voltage protective circuit for preventing the output voltage from exceeding a preset trip level in a direct current power supply which includes series-regulating means connected between the input and output of said power supply comprising means for providing a constant current source, resistance means connected in circuit with said constant current source and the input of said power supply to produce a reference voltage across said resistance means independently of the output voltage of said power supply, means for monitoring and selecting said reference voltage to a desired overvoltage trip level in excess of the present output level, said overvoltage trip level being monitored by an indicating device, means for comparing said adjusted reference voltage with said output voltage of said power supply to provide a control signal when said output voltage equals said reference voltage, crowbar short circuit means connected across the output of said power supply adapted to actuate at said trip level in response to said control signal, and means in response to said control signal to bias said series-regulating means to prevent delivery of current from the input of said power supply to said crowbar short circuit means.

Claim 19

A voltage protective circuit as set forth in claim 10 wherein said power-supply-regulating means is connected to prevent the application of current to said crowbar short circuit means after actuation of said crowbar circuit means.

Claim 20

A voltage protective circuit as set forth in claim 10 in which the adjustment of said reference voltage is monitored by a visual indicating device to provide the desired trip level.

Claim 23

A voltage protective circuit for a power supply comprising a pair of input and output terminals, a source of direct current connected to said input terminals, a voltage current regulator circuit which includes series-regulating means connected between an input and output terminal of said power supply, a current-sensing resistance, a voltage-sensing circuit coupled to a load circuit and said output terminals, an amplifier coupled from the voltage-sensing resistance providing an overvoltage control signal in response to current flow through said sensing resistance, means for coupling the control signal from said sensing resistance to said series-regulating means, a crowbar shorting device connected across said load circuit and adapted to conduct and short circuit said load circuit in response to a trigger signal, a source of reference voltage for setting the trip level of said crowbar device provided independently of the output voltage produced across said load circuit, means for monitoring said reference voltage, means for providing a trigger signal when said output voltage equals said reference voltage, means for applying said trigger signal to said crowbar shorting device, means for adjusting said reference voltage to a desired level of actuation by said trigger signal as provided by said monitoring means, and bias means in response to said trigger signal connected to prevent conduction of said series-regulating means, thereby disabling the flow of current from said source to said crowbar device.

Claim 24

A voltage protective circuit for a power supply comprising a pair of input and output terminals, a source of direct current connected to said input terminals, a voltage current regulator circuit which includes series-regulating means connected between an input and output terminal of said power supply, a current-sensing resistance, a voltage-sensing circuit coupled to a load circuit and said output terminals, an amplifier coupled from the voltage-sensing resistance providing an overvoltage control signal in response to current flow through said sensing resistance, means for coupling the control signal from said sensing resistance to said series-regulating means, a crowbar shorting device connected across said load circuit and adapted to conduct and short circuit said load circuit in response to a trigger signal, a source of reference voltage for setting the trip level of said crowbar device provided independently of the output voltage produced across said load circuit, means for monitoring said reference voltage, means for providing a trigger signal when said output voltage equals said reference voltage, means for applying said trigger signal to said crowbar shorting device, means for adjusting said reference voltage to a desired level of actuation by said trigger signal as provided by said monitoring means, and bias means in response to said trigger signal connected to prevent conduction of said series-regulating means, thereby disabling the flow of current from said source to said crowbar device.