Time division conference hybrid circuit

Claim 2

A time division communication system wherein a plurality of time slots occurs in repetitive cycles comprising a plurality of communication paths, an incoming time division bus, an outgoing time division bus, each communication path having an associated circuit connected to said communication path and selectively connectible to said incoming and outgoing buses, means for exchanging signals among a plurality of selected communication paths comprising means for connecting said incoming bus and said outgoing bus to each selected communication path in a distinct time slot, means connected between said incoming and outgoing buses for producing a signal corresponding to the sum of the selected communication path outgoing signals appearing on said outgoing bus in said distinct time slot, and means for applying said produced signal to said incoming bus in said distinct time slot, each communication path circuit comprising means for storing a sample of said produced signal received from said incoming bus in said distinct time slot, first and second amplifying means each having first and second inputs and an output, said first amplifying means first input being connected to said storing means, said first amplifying means second input being connected to said second amplifying means output, means for coupling said first amplifying means output to said communication path, said second amplifying means first input being connected to said communication path, said second amplifying means second input being connected to said first amplifying means output, means for coupling said second amplifying means output to said outgoing bus in said distinct time slot, said first amplifying means comprising means for canceling the communication path outgoing signal portion of said produced signal with said second amplifying means output signal, said second amplifying means comprising means for cAnceling the portion of the produced signal coupled to said communication path with the first amplifying means output signal.

Claim 3

A time division communication system wherein a plurality of time slots occurs in repetitive cycles according to claim 1 wherein the canceling means in said first amplifying means comprises first means for subtracting a signal corresponding to the communication path outgoing signal on said first amplifying means second input from a signal corresponding to said stored produced signal on the amplifying means first input, the canceling means in said second amplifying means comprises second means for subtracting a signal corresponding to said stored produced signal on said second amplifying means second input from a signal corresponding to the communication path signal on said second amplifying means first input.

Claim 4

A time division communication system wherein a plurality of time slots occurs in repetitive cycles according to claim 2 wherein said first subtracting means comprises means for subtracting twice the communication path outgoing signal on said first amplifying means second input from four times the stored produced signal on said first amplifying means first input, and said second subtracting means comprises means for subtracting one-half the signal coupled to said second amplifying means second input from said first amplifying means output from the communication path signal on said second amplifying means first input, and said means for coupling the first amplifying means output to said communication path comprises impedance means for matching the characteristic impedance of said communication path.

Claim 5

A time division communication system wherein a plurality of time slots occurs in repetitive cycles according to claim 2 wherein each of said first and second subtracting means comprises an operational amplifier.

Claim 6

In a time division communication system wherein a plurality of time slots occurs in repetitive cycles, a circuit for connecting a bidirectional path to an incoming and an outgoing path in a distinct time slot comprising an incoming amplifier having first and second inputs and an output, a store, means for coupling the incoming path to said store in said distinct time slot, means for coupling said store to said incoming amplifier first input, means for coupling the outgoing amplifier output to the incoming amplifier output to the bidirectional path, means for coupling the bidirectional path to said outgoing amplifier first input, means for coupling the incoming amplifier output to said outgoing amplifier second input, and means for coupling the outgoing amplifier output to said outgoing path in said distinct time slot, said incoming amplifier comprising means for canceling the bidirectional path outgoing signal appearing on said store with the bidirectional path outgoing signal appearing on said outgoing amplifier output whereby only the incoming signal is applied to the bidirectional path, said outgoing amplifier comprising means for canceling the incoming path signal appearing on said bidirectional path with the incoming signal on said incoming amplifier output whereby only the bidirectional path outgoing signal is applied to said outgoing path in said distinct time slot.

Claim 7

In a time division communication system wherein a plurality of time slots occurs in repetitive cycles, a circuit for connecting a bidirectional path to an incoming and an outgoing path in a distinct time slot comprising an incoming amplifier having first and second inputs and an output, a store, means for coupling the incoming path to said store in said distinct time slot, means for coupling said store to said incoming amplifier first input, means for coupling the outgoing amplifier output to the incoming amplifier output to the bidirectional path, means for coupling the bidirectional path to said outgoing amplifier first input, means for coupling the incoming amplifier output to said outgoing amplifier second input, and means for coupling the outgoing amplifier output to said outgoing path in said distinct time slot, said incoming amplifier comprising means for canceling the bidirectional path outgoing signal appearing on said store with the bidirectional path outgoing signal appearing on said outgoing amplifier output whereby only the incoming signal is applied to the bidirectional path, said outgoing amplifier comprising means for canceling the incoming path signal appearing on said bidirectional path with the incoming signal on said incoming amplifier output whereby only the bidirectional path outgoing signal is applied to said outgoing path in said distinct time slot.

Claim 8

A time division communication system wherein a plurality of time slots occurs in repetitive cycles comprising a plurality of lines, an incoming bus, an outgoing bus, each line having an associated circuit connected to said line and connectible to said incoming and outgoing buses, means for exchanging signals among a plurality of selected lines comprising means for connecting said incoming bus and said outgoing bus to each selected line circuit in a distinct time slot, a summing amplifier connected from said outgoing bus to said incoming bus for producing a signal proportional to the sum of said selected line outgoing signals appearing on said outgoing bus in said distinct time slot, and means for applying said produced signal to said incoming bus in said Distinct time slot, each line circuit comprising a storage capacitor for storing a sample of said produced signal in said distinct time slot and first and second operational amplifiers each having a positive input, a negative input and an output, means for coupling said produced signal from said storage capacitor to said first operational amplifier positive input, means for coupling the second operational amplifier output to the first operational amplifier negative input, said first operational amplifier comprising means for subtracting a signal proportional to the signal appearing at the output of said second operational amplifier from a signal proportional to said produced signal appearing on said storage capacitor whereby the signals from the other selected lines are transferred to said associated line, means for coupling the signal appearing on said associated line to said second operational amplifier positive input, means for coupling the signal appearing on the first operational amplifier output to the second operational amplifier negative input, and means for coupling the second operational amplifier to said outgoing bus in said distinct time slot, said second operational amplifier comprising means for subtracting a signal proportional to the signal on said first operational amplifier output from a signal proportional to the signal appearing on said associated line whereby the outgoing signal from said associated line is transferred to said outgoing bus in said distinct time slot.

Claim 9

A time division communication system wherein a plurality of time slots occurs in repetitive cycles comprising a plurality of lines, an incoming bus, an outgoing bus, each line having an associated circuit connected to said line and connectible to said incoming and outgoing buses, means for exchanging signals among a plurality of selected lines comprising means for connecting said incoming bus and said outgoing bus to each selected line circuit in a distinct time slot, a summing amplifier connected from said outgoing bus to said incoming bus for producing a signal proportional to the sum of said selected line outgoing signals appearing on said outgoing bus in said distinct time slot, and means for applying said produced signal to said incoming bus in said Distinct time slot, each line circuit comprising a storage capacitor for storing a sample of said produced signal in said distinct time slot and first and second operational amplifiers each having a positive input, a negative input and an output, means for coupling said produced signal from said storage capacitor to said first operational amplifier positive input, means for coupling the second operational amplifier output to the first operational amplifier negative input, said first operational amplifier comprising means for subtracting a signal proportional to the signal appearing at the output of said second operational amplifier from a signal proportional to said produced signal appearing on said storage capacitor whereby the signals from the other selected lines are transferred to said associated line, means for coupling the signal appearing on said associated line to said second operational amplifier positive input, means for coupling the signal appearing on the first operational amplifier output to the second operational amplifier negative input, and means for coupling the second operational amplifier to said outgoing bus in said distinct time slot, said second operational amplifier comprising means for subtracting a signal proportional to the signal on said first operational amplifier output from a signal proportional to the signal appearing on said associated line whereby the outgoing signal from said associated line is transferred to said outgoing bus in said distinct time slot.