Electronically controlled crossbar switch

Claim 2

A cross bar switch forming a matrix of intersecting rows and columns with individual row conductors and column conductors, respectively; a multiplicity of relays at the junctions of respective columns and rows, each of said relays having an operating winding connected between the corresponding row and column conductors and a holding winding in series with an armature of the relay; a multiplicity of row-control circuits each including a normally nonconductive first controlled rectifier connected between a respective row conductor and a source of first operating potential for the operating windings of the associated relays; a multiplicity of column-control circuits each including a normally nonconductive second controlled rectifier connected between a respective column conductor and a source of second operating potential for the operating windings of the associated relays; a multiplicity of maintenance circuits each including a normally nonconductive third controlled rectifier connected betwEen an ancillary conductor common to the holding windings of all the relays of a respective column and a source of operating potential for the energization of the holding winding of a selected relay by way of said armature; a normally inoperative common power supply for all said controlled rectifiers; switch means for temporarily activating said power supply; and selector means for transmitting a firing pulse to a combination of first and second controlled rectifiers in a chosen row-control and column circuit during an operating period of said power supply to energize the operating winding of a selected relay and for substantially simultaneously firing a third controlled rectifier in a corresponding maintenance circuit to energize the holding winding of said selected relay; said maintenance circuits being provided with normally nonconductive transistors shunting said third controlled rectifiers, said transistors having inputs connected to receive disconnect pulses for rendering same conductive to cut off a previously fired third controlled rectifier, thereby releasing the corresponding relay.

Claim 3

A crossbar switch as defined in claim 1, wherein corresponding column-control circuits and maintenance circuits are provided with interconnecting leads for firing said third controlled rectifiers in response to the energization of a corresponding second controlled rectiifer.

Claim 4

A crossbar switch as defined in claim 1 wherein all said controlled rectifiers are provided with reverse-biased shunt diodes for protecting same against transients.

Claim 5

A crossbar switch as defined in claim 1 wherein said power supply comprises a first transistor stage and a second transistor stage controlled by said first stage, said second stage having output leads extending to said row-control and column-control circuits.

Claim 6

A crossbar switch as defined in claim 4 wherein said column-control circuits include respective starting amplifiers for said second controlled rectifiers, said second stage comprising a pair of output transistors for delivering a first operating voltage to said first and second controlled rectifiers and a second operating voltage to said starting transistors.

Claim 7

A crossbar switch as defined in claim 1 wherein said selector means forms part of a command unit common to all said row-control and column-control circuits, said power supply being controlled from said command unit.

Claim 8

A crossbar switch forming a matrix of intersecting rows and columns with individual row conductors and column conductors, respectively; a multiplicity of relays at the junctions of respective columns and rows, each of said relays having an operating winding connected between the corresponding row and column conductors and a holding winding in series with an armature of the relay; a multiplicity of row-control circuits each including a normally nonconductive first controlled rectifier connected between a respective row conductor and a source of first operating potential for the operating windings of the associated relays; a multiplicity of column-control circuits each including a normally nonconductive second controlled rectifier connected between a respective column conductor and a source of second operating potential for the operating windings of the associated relays; a multiplicity of maintenance circuits each including a normally nonconductive third controlled rectifier connected between an ancillary conductor common to the holding windings of all the relays of a respective column and a source of operating potential for the energization of the holding winding of a selected relay by way of said armature; a normally inoperative common power supply for all said controlled rectifiers; switch means for temporarily activating said power supply; and selector means for transmitting a firing pulse to a combination of first and second controlled rectifiers in a chosen row-control and column-control circuit during an operating period of said power supply to energize the operating winding of a selected reLay and for subsequently firing a third controlled rectifier in a corresponding maintenance circuit to energize the holding winding of said selected relay, said column-control circuits being provided with gate means responsive to energization of the third controlled rectifier in a corresponding maintenance circuit for blocking the application of a firing pulse to said second controlled rectifiers; said maintenance circuits being provided with inputs for receiving disconnect pulses deenergizing a previously fired third controlled rectifier to release the corresponding relay.

Claim 9

A crossbar switch forming a matrix of intersecting rows and columns with individual row conductors and column conductors, respectively; a multiplicity of relays at the junctions of respective columns and rows, each of said relays having an operating winding connected between the corresponding row and column conductors and a holding winding in series with an armature of the relay; a multiplicity of row-control circuits each including a normally nonconductive first controlled rectifier connected between a respective row conductor and a source of first operating potential for the operating windings of the associated relays; a multiplicity of column-control circuits each including a normally nonconductive second controlled rectifier connected between a respective column conductor and a source of second operating potential for the operating windings of the associated relays; a multiplicity of maintenance circuits each including a normally nonconductive third controlled rectifier connected between an ancillary conductor common to the holding windings of all the relays of a respective column and a source of operating potential for the energization of the holding winding of a selected relay by way of said armature; a normally inoperative common power supply for all said controlled rectifiers; switch means for temporarily activating said power supply; and selector means for transmitting a firing pulse to a combination of first and second controlled rectifiers in a chosen row-control and column-control circuit during an operating period of said power supply to energize the operating winding of a selected reLay and for subsequently firing a third controlled rectifier in a corresponding maintenance circuit to energize the holding winding of said selected relay, said column-control circuits being provided with gate means responsive to energization of the third controlled rectifier in a corresponding maintenance circuit for blocking the application of a firing pulse to said second controlled rectifiers; said maintenance circuits being provided with inputs for receiving disconnect pulses deenergizing a previously fired third controlled rectifier to release the corresponding relay.

Claim 10

A crossbar switch as defined in claim 7 wherein corresponding column-control circuits and maintenance circuits are provided with interconnecting leads for firing said third controlled rectifiers in response to the energization of a corresponding second controlled rectifier, said leads being provided with delay networks for retarding the energization of said third controlled rectifiers.

Claim 11

A crossbar switch as defined in claim 7 wherein said maintenance circuits are provided with normally nonconductive transistors shunting said third controlled rectifiers, said inputs terminating at said transistors for rendering same conductive to cut off the associated controlled rectifiers.

Claim 12

A crossbar switch forming a matrix of intersecting rows and columns with individual row conductors and column conductors, respectively; a multiplicity of relays at the junctions of respective columns and rows, each of said relays having an operating winding connected between the corresponding row and column conductors and a holding winding in series with an armature of the relay; a multiplicity of row-control circuits each including a normally nonconductive first controlled rectifier connected between a respective row conductor and a source of first operating potential for the operating windings of the associated relays; a multiplicity of column-control circuits each including a normally nonconductive second controlled rectifier connected between a respective column conductor, a starting amplifier for said second controlled rectifier and a source of second operating potential for the operating windings of the associated relays; a multiplicity of maintenance circuits each including a normally nonconductive third controlled rectifier connected between an ancillary conductor common to the holding windings of all the relays of a respective column and a source of operating potential for the energization of the holding winding of a selected relay by way of said armature; a normally inoperative common power supply for all said controlled rectifiers; switch means for temporarily activating said power supply; and selector means for transmitting a firing pulse to a combination of first and second controlled rectifiers in a chosen row-control and column-control circuit during an operating period of said power supply to energize the operating winding of a selected relay and for substantially simultaneously firing a third controlled rectifier in a corresponding maintenance circuit to energize the holding winding of said selected relay, said maintenance circuits being provided with inputs for receiving disconnect pulses deenergizing a previously fired third controlled rectifier to release the corresponding relay; said power supply comprising a first transistor stage and a second transistor stage controlled by said first stage, said second stage including a pair of output transistors for delivering a first operating voltage to said first and second controlled rectifiers and a second operating voltage to said starting transistors.

Claim 13

A crossbar switch forming a matrix of intersecting rows and columns with individual row conductors and column conductors, respectively; a multiplicity of relays at the junctions of respective columns and rows, each of said relays having an operating winding connected between the corresponding row and column conductors and a holding winding in series with an armature of the relay; a multiplicity of row-control circuits each including a normally nonconductive first controlled rectifier connected between a respective row conductor and a source of first operating potential for the operating windings of the associated relays; a multiplicity of column-control circuits each including a normally nonconductive second controlled rectifier connected between a respective column conductor, a starting amplifier for said second controlled rectifier and a source of second operating potential for the operating windings of the associated relays; a multiplicity of maintenance circuits each including a normally nonconductive third controlled rectifier connected between an ancillary conductor common to the holding windings of all the relays of a respective column and a source of operating potential for the energization of the holding winding of a selected relay by way of said armature; a normally inoperative common power supply for all said controlled rectifiers; switch means for temporarily activating said power supply; and selector means for transmitting a firing pulse to a combination of first and second controlled rectifiers in a chosen row-control and column-control circuit during an operating period of said power supply to energize the operating winding of a selected relay and for substantially simultaneously firing a third controlled rectifier in a corresponding maintenance circuit to energize the holding winding of said selected relay, said maintenance circuits being provided with inputs for receiving disconnect pulses deenergizing a previously fired third controlled rectifier to release the corresponding relay; said power supply comprising a first transistor stage and a second transistor stage controlled by said first stage, said second stage including a pair of output transistors for delivering a first operating voltage to said first and second controlled rectifiers and a second operating voltage to said starting transistors.

Claim 14

A crossbar switch as defined in claim 10 wherein said column-control circuits are provided with gate means responsive to energization of the third controlled rectifier in a corresponding maintenance circuit for blocking the application of a firing pulse to said second controlled rectifiers.

Claim 15

A crossbar switch as defined in claim 10 where in said output transistors are of opposite conductivity types anD said operating voltages are of opposite polarities.