Polarity reversal switching circuit

Claim 2

A voltage polarity reversal switching circuit comprising a first and second terminal pair, a third and fourth terminal pair, a first d.c. voltage source, a second d.c. voltage source, control means for producing first and second control signals, first means connected to said first d.c. voltage source and said first and third terminals responsive to said first control signal for establishing a signal path between said first and third terminals and for supplying said first d.c. voltage from said first d.c. voltage source to said first and third terminals, second means connected to said second d.c. voltage source and said second and fourth terminals responsive to said first control signal for establishing a signal path between said second and fourth terminals and for supplying said second d.c. voltage from said second d.c. voltage source to said second and fourth terminals, third means connected to said first d.c. voltage source and said first and fourth terminals responsive to said second control signal for establishing a signal path between said first and fourth terminals and for supplying said first d.c. voltage from said first d.c. voltage source to said first and fourth terminals, and fourth means connected between said second d.c. voltage source and said second and third terminals responsive to said second control signal for establishing a signal path between said second and third terminals and for supplying said second d.c. voltage from said second d.c. voltage source to said second and third terminals whereby the d.c. voltage polarity across said first and second terminal pair remains invariant and the voltage polarity across said third and fourth terminal pair is reversible.

Claim 3

A polarity reversal switching circuit comprising a first and second terminal pair, a third and fourth terminal pair, a first d.c. voltage source, a second d.c. voltage source, control means for generating first and second control signals, first switching means connected between said first and third terminals and to said first d.c. voltage source responsive to said first control signal for applying the first d.c. voltage from said first d.c. voltage source to said first and third terminals and for maintaining a bidirectional signal path between said first and third terminals, second switching means connected between said second and fourth terminals and to said second d.c. voltage source responsive to said first control signal for applying said d.c. voltage from said second d.c. voltage source to said second and fourth terminals and for maintaining a bidirectional signal path between said second and fourth terminals, third switching means connected between said first and fourth terminals and to said first d.c. voltage source responsive to said second control signal for applying said first d.c. voltage from said first d.c. voltage source to said first and fourth terminals and for maintaining a bidirectional signal path between said first and fourth terminals, and fourth switching means connected between said second and third terminals and to said second d.c. voltage source responsive to said second control signal for applying said second d.c. voltage from said second d.c. voltage source to said second and third terminals and for maintaining a bidirectional signal path between said second and third terminals.

Claim 4

A polarity reversal switching circuit comprising a first and second terminal pair, a third and fourth terminal pair, a first d.c. voltage source, a second d.c. voltage source, control means for generating first and second control signals, first switching means connected between said first and third terminals and to said first d.c. voltage source responsive to said first control signal for applying the first d.c. voltage from said first d.c. voltage source to said first and third terminals and for maintaining a bidirectional signal path between said first and third terminals, second switching means connected between said second and fourth terminals and to said second d.c. voltage source responsive to said first control signal for applying said d.c. voltage from said second d.c. voltage source to said second and fourth terminals and for maintaining a bidirectional signal path between said second and fourth terminals, third switching means connected between said first and fourth terminals and to said first d.c. voltage source responsive to said second control signal for applying said first d.c. voltage from said first d.c. voltage source to said first and fourth terminals and for maintaining a bidirectional signal path between said first and fourth terminals, and fourth switching means connected between said second and third terminals and to said second d.c. voltage source responsive to said second control signal for applying said second d.c. voltage from said second d.c. voltage source to said second and third terminals and for maintaining a bidirectional signal path between said second and third terminals.

Claim 5

A polarity reversal switch circuit according to claim 2 wherein said first switching means comprises a coupling device having first, second and control electrodes and a pair of switching devices each having first and second electrodes, said coupling device first electrode being connected to said first d.c. voltage source, the first electrodes of said switching devices being joined together, means for connecting said coupling device second electrode to the junction of said switching device first electrodes, the second electrode of one of said switching devices bEing connected to said first terminal, the second electrode of said other switching device being connected to said third terminal, and means connected between said control means and said coupling device control electrode for applying said first control signal to said coupling device control electrode, said coupling device and said pair of switching devices being rendered conductive reponsive to said first control signal.

Claim 6

A polarity reversal switch circuit according to claim 3 wherein said second switching means comprises a coupling device having first, second and control electrodes and a pair of switching devices, each having first and second electrodes, said coupling device first electrode being connected to said second d.c. voltage source, the second electrodes of said switching devices being joined together, means for connecting said coupling device second electrode to the junction of said switching device second electrodes, the first electrode of one of said switching devices being connected to said second terminal, the first electrode of said other switching device being connected to said fourth terminal, and means connected between said control means and said coupling device control electrode for applying said first control signal to said coupling device control electrode, said second switching means coupling device and pair of switching devices being rendered conductive responsive to said first control signal.

Claim 7

A polarity reversal switch circuit according to claim 4 wherein said third switching means comprises a coupling device having first, second and control electrodes and a pair of switching devices each having first and second electrodes, said coupling device first electrode being connected to said first d.c. voltage source, the first electrodes of said switching devices being joined together, means for connecting said coupling device second electrode to the junction of said switching device first electrodes, the second electrode of one of said switching devices being connected to said first terminal, the second electrode of other switching device being connected to said fourth terminal, and means connected between said control means and said coupling device control electrode for applying said second control signal to said coupling device control electrode, said third switching means coupling device and pair of switching devices being rendered conductive responsive to said second control signal.

Claim 8

A polarity reversal switch circuit according to claim 5 wherein said fourth switching means comprises a coupling device having first, second and control electrodes and a pair of switching devices each having first and second electrodes, said coupling device first electrode being connected to said second d.c. voltage source, the second electrodes of said switching devices being joined together, means for connecting said coupling device second electrode to the junction of said switching device second electrodes, the first electrode of one of said switching devices being connected to said second terminal, the first electrode of said other switching device being connected to said third terminal, and means connected between said control means and said coupling device control electrode for applying said second control signal to said coupling device control electrode, said fourth switching means coupling device and said pair of switching devices being rendered conductive responsive to said second control signal.

Claim 9

A polarity reversal switch circuit according to claim 6 wherein each switching means coupling device comprises a transistor having a collector, an emitter and a base, said transistor collector corresponding to said coupling device first electrode, said transistor emitter corresponding to said coupling device second electrode, and said transistor base corresponding to said coupling device control electrode, and each of said first, second, third and fourth switching means switching device comprises a diode having an anode and a cathode, said diode anoDe corresponding to said switching device first electrode, and said diode cathode corresponding to said switching device second electrode.

Claim 10

A polarity reversal switch circuit according to claim 7 wherein each first and third switching means transistor comprises an NPN transistor and wherein each second and fourth switching means transistor comprises a PNP transistor.

Claim 11

A polarity reversal switching circuit according to claim 8 wherein said first d.c. voltage source comprises a positive d.c. voltage source and said second d.c. voltage source comprises a negative d.c. voltage source.

Claim 12

A polarity reversal switching circuit according to claim 8 wherein said first d.c. voltage source comprises a ground reference voltage source and said second d.c. voltage source comprises a negative battery.

Claim 13

In a communication system having an electronic trunk circuit and a trunk, a polarity reversal circuit connected between said circuit and said trunk comprising first and second terminals connected to said circuit and third and fourth terminals connected to said trunk, a relatively positive voltage source, a relatively negative voltage source, means for generating first and second control signals, first means connected to said positive voltage source and said first and third terminals responsive to said first control signal for supplying a relatively positive voltage from said positive voltage source to said first and third terminals and for transmitting signals between said first and third terminals, second means connected to said negative voltage source and said second and fourth terminals responsive to said first control signal for supplying a relatively negative voltage from said negative voltage source to said second and fourth terminals and for transmitting signals between said second and fourth terminals, third means connected to said positive voltage source and said first and fourth terminals responsive to said second control signal for supplying a relatively positive voltage from said positive voltage source to said first and fourth terminals and for transmitting signals between said first and fourth terminals, and fourth means connected to said negative voltage source and said second and third terminals responsive to said second control signal for supplying a relatively negative voltage from said negative voltage source to said second and third terminals, and for transmitting signals between said second and third terminals.

Claim 14

In a communication system having an electronic trunk circuit and a trunk, a polarity reversal circuit connected between said circuit and said trunk comprising first and second terminals connected to said circuit and third and fourth terminals connected to said trunk, a relatively positive voltage source, a relatively negative voltage source, means for generating first and second control signals, first means connected to said positive voltage source and said first and third terminals responsive to said first control signal for supplying a relatively positive voltage from said positive voltage source to said first and third terminals and for transmitting signals between said first and third terminals, second means connected to said negative voltage source and said second and fourth terminals responsive to said first control signal for supplying a relatively negative voltage from said negative voltage source to said second and fourth terminals and for transmitting signals between said second and fourth terminals, third means connected to said positive voltage source and said first and fourth terminals responsive to said second control signal for supplying a relatively positive voltage from said positive voltage source to said first and fourth terminals and for transmitting signals between said first and fourth terminals, and fourth means connected to said negative voltage source and said second and third terminals responsive to said second control signal for supplying a relatively negative voltage from said negative voltage source to said second and third terminals, and for transmitting signals between said second and third terminals.

Claim 15

In a communication system having an electronic trunk circuit and a trunk, a polarity reversal circuit according to claim 11 wherein each of said first and third means comprises a transistor having a collector, an emitter and a base and first and second diodes each having an anode and a cathode, said transistor collector being connected to said positive voltage source, said first diode anode being connected to said second diode anode, means for connecting said transistor emitter to the junction of said first and second diode anodes, means for connecting said control source generating means to said transistor base, said first means first diode cathode being connected to said first terminal and said first means second diode cathode being connected to said third terminal, said third means first diode cathode being connected to said first terminal and said third means second diode cathode being connected to said fourth terminal.

Claim 16

In a communication system having an electronic trunk circuit and a trunk, a polarity reversal circuit according to claim 12 wherein each of said second and fourth means comprises a transistor having a collector, an emitter and a base and third and fourth diodes each having an anode and a cathode, said transistor collector being connected to said negative voltage source, said third diode cathode being connected to said fourth diode cathode, means for connecting said transistor emitter to the junction of said third and fourth diode cathodes, and means for connecting said control signal generating means to said traNsistor base, said second means third diode anode being connected to said second terminal and said second means fourth diode anode being connected to said fourth terminal, said fourth means third diode anode being connected to said second terminal and said fourth means fourth diode anode being connected to said third terminal.

Claim 17

In combination, an electronic exchange circuit, a central office, a trunk connected to said central office, and a polarity reversal circuit connected between said exchange circuit and said trunk comprising first and second terminals connected to said exchange circuit, third and fourth terminals connected to said trunk, a relatively positive voltage source, a relatively negative voltage source, means for generating first and second control signals, first means responsive to said first control signal for coupling said positive voltage source to said first and third terminals and for providing a signal path between said first and third terminals comprising a transistor having a collector, an emitter and a base, a pair of diodes each having a anode and a cathode, said transistor collector being connected to said positive voltage source, said diode anodes being connected together, means for connecting said transistor emitter to the junction of said diode anodes, means for applying said first control signal to said transistor base, the cathode of one of said diodes being connected to said first terminal and the cathode of the other of said diodes being connected to said third terminal, second means responsive to said first control signal for coupling said negative voltage source to said second and fourth terminals and for providing a signal path between said second and fourth terminals comprising a transistor having a collector, an emitter and a base and a pair of diodes each having an anode and a cathode, said transistor collector being connected to said negative voltage source, said diode cathodes being connected together, means for connecting said transistor emitter to the junction of said diode cathodes, means for applying said first control signal to said transistor base, the anode of one of said diodes being connected to said second terminal and the anode of the other of said diodes being connected to said fourth terminal, third means responsive to said second control signal for coupling said positive voltage source to said first and fourth terminals and for providing a signal path between said first and fourth terminals comprising a transistor having a collector, an emitter and a base and a pair of diodes each having an anode and a diode, said transistor collector being connected to said positive voltage source, said diode anodes being connected together, means for connecting said transistor emitter to the junction of said diode anodes, means for applying said second control signal to said transistor base, the cathode of one of said diodes being connected to said first terminal and the cathode of the other of said diodes being connected to said fourth terminal, and fourth means responsive to said second control signal for coupling said negative voltage source to said second and third terminals and for providing a signal path between said second and third terminals comprising a transistor having a collector, an emitter and a base and a pair of diodes each having an anode and a cathode, said transistor collector being connected to said negative voltage source, said diode cathodes being connected together, means for connecting said transistor emitter to the junction of said diode cathodes, means for applying said second control signal to said transistor base, the anode of one of said diodes being connected to said second terminal and the anode of the other of said diodes being connected to said third terminal.

Claim 18

In combination, an electronic exchange circuit, a central office, a trunk connected to said central office, and a polarity reversal circuit connected between said exchange circuit and said trunk comprising first and second terminals connected to said exchange circuit, third and fourth terminals connected to said trunk, a relatively positive voltage source, a relatively negative voltage source, means for generating first and second control signals, first means responsive to said first control signal for coupling said positive voltage source to said first and third terminals and for providing a signal path between said first and third terminals comprising a transistor having a collector, an emitter and a base, a pair of diodes each having a anode and a cathode, said transistor collector being connected to said positive voltage source, said diode anodes being connected together, means for connecting said transistor emitter to the junction of said diode anodes, means for applying said first control signal to said transistor base, the cathode of one of said diodes being connected to said first terminal and the cathode of the other of said diodes being connected to said third terminal, second means responsive to said first control signal for coupling said negative voltage source to said second and fourth terminals and for providing a signal path between said second and fourth terminals comprising a transistor having a collector, an emitter and a base and a pair of diodes each having an anode and a cathode, said transistor collector being connected to said negative voltage source, said diode cathodes being connected together, means for connecting said transistor emitter to the junction of said diode cathodes, means for applying said first control signal to said transistor base, the anode of one of said diodes being connected to said second terminal and the anode of the other of said diodes being connected to said fourth terminal, third means responsive to said second control signal for coupling said positive voltage source to said first and fourth terminals and for providing a signal path between said first and fourth terminals comprising a transistor having a collector, an emitter and a base and a pair of diodes each having an anode and a diode, said transistor collector being connected to said positive voltage source, said diode anodes being connected together, means for connecting said transistor emitter to the junction of said diode anodes, means for applying said second control signal to said transistor base, the cathode of one of said diodes being connected to said first terminal and the cathode of the other of said diodes being connected to said fourth terminal, and fourth means responsive to said second control signal for coupling said negative voltage source to said second and third terminals and for providing a signal path between said second and third terminals comprising a transistor having a collector, an emitter and a base and a pair of diodes each having an anode and a cathode, said transistor collector being connected to said negative voltage source, said diode cathodes being connected together, means for connecting said transistor emitter to the junction of said diode cathodes, means for applying said second control signal to said transistor base, the anode of one of said diodes being connected to said second terminal and the anode of the other of said diodes being connected to said third terminal.

Claim 19

A polarity reversal circuit connected between an electronic device and a transmission path comprising first and second terminals connected to said electronic device, third and fourth terminals connected to said transmission path, a fiRst voltage source, a second voltage source, means for generating first and second control signals, first means responsive to said first control signal for applying said first voltage from said first voltage source to said first and third terminals and said second voltage from said second voltage source to said second and fourth terminals and for coupling signals between said electronic device and said transmission path, and second means responsive to said second control signal for applying said first voltage from said first voltage source to said first and fourth terminals and said second voltage from said second voltage source to said second and third terminals and for coupling signals between said electronic device and said transmission path whereby the voltage polarity across said first and second terminals remains invariant and the voltage polarity across said third and fourth terminals is reversible.

Claim 20

A polarity reversal circuit connected between an electronic device and a transmission path comprising first and second terminals connected to said electronic device, third and fourth terminals connected to said transmission path, a fiRst voltage source, a second voltage source, means for generating first and second control signals, first means responsive to said first control signal for applying said first voltage from said first voltage source to said first and third terminals and said second voltage from said second voltage source to said second and fourth terminals and for coupling signals between said electronic device and said transmission path, and second means responsive to said second control signal for applying said first voltage from said first voltage source to said first and fourth terminals and said second voltage from said second voltage source to said second and third terminals and for coupling signals between said electronic device and said transmission path whereby the voltage polarity across said first and second terminals remains invariant and the voltage polarity across said third and fourth terminals is reversible.