Apparatus for connecting transmission channels

Claim 2

Apparatus for connecting transmission channels, for telegraphy switching, particularly for automatic telegraph switching equipment, characterized in that a transmission channel is divided into two sections, said apparatus comprising a receiver and a transmitter connected in series between the respective sections of each channel, the two sections independently receivIng and transmitting signals on either side of the connecting apparatus, and means for selectively making and breaking the connection between said two sections of each channel, wherein said receiver and transmitter are formed of semiconductor elements and wherein said apparatus further includes a central control means having access to both of said sections for selectively actuating said means for making and breaking the connection between said two sections of each channel, wherein two transmission channels are provided, a transmitter and a receiver being provided in series in each of the two channels, said central control means includes individual inhibitory control means for enabling each of the two receivers to selectively produce at the output thereof modified forms of the signals received at the input thereof, wherein said transmission channels are situated between a calling subscriber and a called subscriber and each includes a line wire, each line wire including a receiver and a transmitter in series, the transmitter being switchably coupled to the respective polarities of the telegraph battery, each line being divided into two sections by said making and breaking means and means being provided to enable each section to communicate separately with said central control means, the modulation received on one of the sections being retransmitted on the other, but each of the two sections separately receiving and transmitting signals, one from the transmitting subscriber and the other from the transmitter of the connecting apparatus, so that said transmitter of the connecting apparatus, which constitutes at the same time a repeater between the two sections, enables each section to have a greater length without reduction of the usually accepted line current.

Claim 3

Apparatus according to claim 1, wherein said receiver for the signals arriving in the channel comprises a common point for the detection of positive and negative signals, the said common point being connected through a resistor and a first diode in series to the base of an output transistor of the receiver and also through a second diode to an input of said central control means, the first diode having its cathode connected to said resistor and its anode connected to the base of said output transistor, the cathode of said first diode being connected by an inhibitory wire to said central control means, the anode of said first diode being connected on the one hand to one polarity voltage through a resistor and on the other hand to an output wire of said central control means so that said central control means, by applying a polarity of appropriate direction to said first diode through said inhibitory wire renders the said first diode nonconductive and thus separates the reception of the signals received along the channel from the transmission of the signals by said central control member to said output transistor, and so that when said central control member does not apply any inhibitory polarity to said first diode, the signals received along the line at said common point are directly transmitted through said resistor and said first diode to the base of said output transistor.

Claim 4

Apparatus according to claim 2, wherein signals are received in bipolar form by said receiver and are transmitted to said transmitter by said output transistor of the receiver in return-to-zero form, the collector of the output transistor being connected to the input of the transmitter which is switchably coupled to the positive and negative polarity voltages from the telegraph battery, said receiver including means for applying to the collector of the output transistor thereof on reception of a positive signal a certain potential which produces in the transmitter the emission of the positive telegraph polarity, on reception of a negative signal by the receiver the output transistor of the receiver providing no potential to its collector, this state producing in the transmitter the emission of the negative telegraph polarity.

Claim 5

Apparatus accOrding to claim 3, wherein, in the channel emanating from the calling subscriber, are connected two diodes connected to the input of the receiver, the output of the receiver being connected to the input of the transmitter, the output of which constituting the channel in communication with the called subscriber, the same arrangement, disposed symmetrically, being present in each transmission channel, the channels being divided into two sections without metallic continuity, the first of which sections is formed by a first wire of which the receiver and the transmitter constitute the terminal elements, and the second section being formed of the output and said first wire extended towards the called subscriber.

Claim 6

Apparatus for connecting transmission channels, for telegraph switching, particularly for automatic telegraph switching equipment, characterized in that a transmission channel is divided into two sections, said apparatus comprising a receiver and a transmitter connected in series between the respective sections of each channel, the two sections independently receiving and transmitting signals, on either side of the connecting apparatus, and means for selectively making and breaking the connection between said two sections of the channel, wherein said making and breaking means includes a central control means for selectively applying control signals to said receiver effective to inhibit the output thereof, wherein said transmission channel is formed by a communication line, said two sections being formed by a calling subscriber end of said line connected to the input of the receiver and a called subscriber end of said line connected to the output of the transmitter and, wherein said receiver for the signals arriving in the channel comprises a common point for the detection of positive and negative signals, the said common point being connected through a resistor and a first diode in series to the base of an output transistor of the receiver and also through a second diode to an input of said central control means, the first diode having its cathode connected to said resistor and its anode connected to the base of said output transistor, the cathode of said first diode being connected by an inhibitory wire to said central control means, the anode of said first diode being connected on the one hand to one polarity voltage through a resistor and on the other hand to an output wire of said central control means so that said central control means, by applying a polarity voltage of appropriate direction to said first diode through said inhibitory wire renders the said first diode nonconductive and thus separates the reception of the signals received along the channel from the transmission of the signals by said central control member to said output transistor, and so that when said central control member does not apply any inhibitory polarity to said first diode, the signals received along the line at said common point are directly transmitted through said resistor and said first diode to the base of said output transistor.

Claim 7

Apparatus for connecting transmission channels, for telegraph switching, particularly for automatic telegraph switching equipment, characterized in that a transmission channel is divided into two sections, said apparatus comprising a receiver and a transmitter connected in series between the respective sections of each channel, the two sections independently receiving and transmitting signals, on either side of the connecting apparatus, and means for selectively making and breaking the connection between said two sections of the channel, wherein said making and breaking means includes a central control means for selectively applying control signals to said receiver effective to inhibit the output thereof, wherein said transmission channel is formed by a communication line, said two sections being formed by a calling subscriber end of said line connected to the input of the receiver and a called subscriber end of said line connected to the output of the transmitter and, wherein said receiver for the signals arriving in the channel comprises a common point for the detection of positive and negative signals, the said common point being connected through a resistor and a first diode in series to the base of an output transistor of the receiver and also through a second diode to an input of said central control means, the first diode having its cathode connected to said resistor and its anode connected to the base of said output transistor, the cathode of said first diode being connected by an inhibitory wire to said central control means, the anode of said first diode being connected on the one hand to one polarity voltage through a resistor and on the other hand to an output wire of said central control means so that said central control means, by applying a polarity voltage of appropriate direction to said first diode through said inhibitory wire renders the said first diode nonconductive and thus separates the reception of the signals received along the channel from the transmission of the signals by said central control member to said output transistor, and so that when said central control member does not apply any inhibitory polarity to said first diode, the signals received along the line at said common point are directly transmitted through said resistor and said first diode to the base of said output transistor.

Claim 8

Apparatus according to claim 5, wherein signals are received in bipolar form by said receiver and are transmitted to said transmitter by said output transistor of the receiver in return-to-zero form, the collector of the output transistor being connected to the input of the transmitter, which is switchably connected to the positive and negative polarity voltages from the telegraph battery, said receiver including means for applying to the collector of the output transistor thereof on reception of a positive signal a certain potential which produces in the transmitter the emission of the positive telegraph polarity, on reception of a negative signal by the receiver the output transistor of the receiver providing no potential to its collector, this state producing in the transmitter the emission of the negative telegraph polarity.

Claim 9

Apparatus according to claim 6, wherein, in the channel emanating from the calling subscriber, are connecteD two diodes connected to the input of the receiver, the output of the receiver being connected to the input of the transmitter.