Cycloconverter silicon controlled rectifier gate signal inhibit circuit

Claim 2

In a cycloconverter system, a gate signal inhibit circuit for maintaining the gate signal circuit of a corresponding cycloconverter silicon controlled rectifier interrupted when the anode-cathode potential across the silicon controlled rectifier is of a magnitude greater than a predetermined maximum comprising in combination with a silicon controlled rectifier gate switch of the type which produces an output potential gate signal, a corresponding cycloconverter silicon controlled rectifier having anode, cathode and gate electrodes and a gate signal circuit through which the silicon controlled rectifier gate switch output potential signal is applied across the gate-cathode electrodes of the corresponding cycloconverter silicon controlled rectifier in a forward polarity relationship, means for Producing a sensing potential signal of a magnitude proportional to the magnitude of the anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier, and a potential sensitive switching device having current carrying elements connected in said gate signal circuit and responsive to said silicon controlled rectifier gate switch output potential gate signal for establishing said gate signal circuit and to said sensing potential signal for maintaining said gate signal circuit interrupted when the forward anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier is of a magnitude greater than a predetermined maximum.

Claim 3

In a cycloconverter system, a gate signal inhibit circuit for maintaining the gate signal circuit of a corresponding cycloconverter silicon controlled rectifier interrupted when the anode-cathode potential across the silicon controlled rectifier is of a magnitude greater than a predetermined maximum comprising in combination with a silicon controlled rectifier gate switch of the type which produces an output potential gate signal, a corresponding cycloconverter silicon controlled rectifier having anode-cathode and gate electrodes and a gate signal circuit through which the silicon controlled rectifier gate switch output potential signal is applied across the gate-cathode electrodes of the corresponding cycloconverter silicon controlled rectifier in a forward polarity relationship, means for producing a sensing potential signal of a magnitude proportional to the magnitude of the anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier, at least one switching transistor having two current carrying electrodes connected in series in said gate signal circuit and a control electrode, means for applying said silicon controlled rectifier gate switch output potential gate signal across a selected one of said current carrying electrodes and said control electrode of said switching transistor in a forward polarity relationship, and means for applying said sensing potential across said selected one of said current carrying electrodes and said control electrode of said switching transistor in an inverse polarity relationship whereby said switching transistor is maintained not conductive when the forward anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier is of a magnitude greater than a predetermined maximum.

Claim 4

In a cycloconverter system, a gate signal inhibit circuit for maintaining the gate signal circuit of a corresponding cycloconverter silicon controlled rectifier interrupted when the anode-cathode potential across the silicon controlled rectifier is of a magnitude greater than a predetermined maximum comprising in combination with a silicon controlled rectifier gate switch of the type which produces an output potential gate signal, a corresponding cycloconverter silicon controlled rectifier having anode-cathode and gate electrodes and a gate signal circuit through which the silicon controlled rectifier gate switch output potential signal is applied across the gate-cathode electrodes of the corresponding cycloconverter silicon controlled rectifier in a forward polarity relationship, means for producing a sensing potential signal of a magnitude proportional to the magnitude of the anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier, at least one switching transistor having two current carrying electrodes connected in series in said gate signal circuit and a control electrode, means for applying said silicon controlled rectifier gate switch output potential gate signal across a selected one of said current carrying electrodes and said control electrode of said switching transistor in a forward polarity relationship, and means for applying said sensing potential across said selected one of said current carrying electrodes and said control electrode of said switching transistor in an inverse polarity relationship whereby said switching transistor is maintained not conductive when the forward anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier is of a magnitude greater than a predetermined maximum.

Claim 5

In a cycloconverter system, a gate signal inhibit circuit for maintaining the gate signal circuit of a corresponding cycloconverter silicon controlled rectifier interrupted when the anode-cathode potential across the silicon controlled rectifier is of a magnitude greater than a predetermined maximum comprising in combination with a silicon controlled rectifier gate switch of the type which produces an output potential gate signal, a corresponding cycloconverter silicon controlled rectifier having anode, cathode and gate electrodes and a gate signal circuit through which the silicon controlled rectifier gate switch output potential signal is applied across the gate-cathode electrodes of the corresponding cycloconverter silicon controlled rectifier in a forward polarity relationship, means for producing a sensing potential signal of a magnitude proportional to the magnitude of the anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier, at least one switching transistor having collector and emitter electrodes connected in series in said gate signal circuit and a base electrode, means for applying said silicon controlled rectifier gate switch output potential gate signal across said base-emitter electrodes of said switching transistor in a forward polarity relationship, and means for applying said sensing potential across said base-emitter electrodes of said switching transistor in an inverse polarity relationship whereby said switching transistor is maintained not conductive when the forWard anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier is of a magnitude greater than a predetermined maximum.

Claim 6

In a cycloconverter system, a gate signal inhibit circuit for maintaining the gate signal circuit of a corresponding cycloconverter silicon controlled rectifier interrupted when the anode-cathode potential across the silicon controlled rectifier is of a magnitude greater than a predetermined maximum comprising in combination with a silicon controlled rectifier gate switch of the type which produces an output potential gate signal, a corresponding cycloconverter silicon controlled rectifier having anode, cathode and gate electrodes and a gate signal circuit through which the silicon controlled rectifier gate switch output potential signal is applied across the gate-cathode electrodes of the corresponding cycloconverter silicon controlled rectifier in a forward polarity relationship, means for producing a sensing potential signal of a magnitude proportional to the magnitude of the anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier, at least one switching transistor having collector and emitter electrodes connected in series in said gate signal circuit and a base electrode, means for applying said silicon controlled rectifier gate switch output potential gate signal across said base-emitter electrodes of said switching transistor in a forward polarity relationship, and means for applying said sensing potential across said base-emitter electrodes of said switching transistor in an inverse polarity relationship whereby said switching transistor is maintained not conductive when the forWard anode-cathode potential across said corresponding cycloconverter silicon controlled rectifier is of a magnitude greater than a predetermined maximum.

Claim 7

In a cycloconverter system, a gate signal inhibit circuit for maintaining the gate signal circuit of a corresponding cycloconverter silicon controlled rectifier interrupted when the anode-cathode potential across the silicon controlled rectifier is of a magnitude greater than a predetermined maximum comprising in combination with a silicon controlled rectifier gate switch of the type which produces an output potential gate signal, a corresponding cycloconverter silicon controlled rectifier having anode, cathode and gate electrodes and a gate signal circuit through which the silicon controlled rectifier gate switch output potential signal is applied across the gate-cathode electrodes of the corresponding cycloconverter silicon controlled rectifier in a forward polarity relationship, first and second resistors, means for connecting said first and second resistors in series across said anode-cathode electrodes of said corresponding cycloconverter silicon controlled rectifier, at least one switching transistor having collector and emitter electrodes connected in series in said gate signal circuit and a base electrode, means for applying said silicon controlled rectifier gate switch output potential gate signal across said base-emitter electrodes of said switching transistor in a forward polarity relationship, and means for connecting said base electrode of said switching transistor to the junction between said first and second resistors.

Claim 8

In a cycloconverter system, a gate signal inhibit circuit for maintaining the gate signal circuit of a corresponding cycloconverter silicon controlled rectifier interrupted when the anode-cathode potential across the silicon controlled rectifier is of a magnitude greater than a predetermined maximum comprising in combination with a silicon controlled rectifier gate switch of the type which produces an output potential gate signal, a corresponding cycloconverter silicon controlled rectifier having anode, cathode and gate electrodes and a gate signal circuit through which the silicon controlled rectifier gate switch output potential signal is applied across the gate-cathode electrodes of the corresponding cycloconverter silicon controlled rectifier in a forward polarity relationship, first and second resistors, means for connecting said first and second resistors in series across said anode-cathode electrodes of said corresponding cycloconverter silicon controlled rectifier, at least one switching transistor having collector and emitter electrodes connected in series in said gate signal circuit and a base electrode, means for applying said silicon controlled rectifier gate switch output potential gate signal across said base-emitter electrodes of said switching transistor in a forward polarity relationship, and means for connecting said base electrode of said switching transistor to the junction between said first and second resistors.