Abstract: An asynchronous, regenerative, digital repeater for use in bipolar digital signalling systems includes an amplifier for receiving and amplifying incoming signals, a first monostable multivibrator for producing regenerated pulses responsively to the output of the amplifier, an output circuit for producing a bipolar pulse train responsively to the output of the multivibrator, and a second multivibrator for inhibiting the first multivibrator for a predetermined interval following the trailing edge of each output pulse to prevent the first multivibrator from responding to the electrical overshoot at the trailing edges of the incoming pulses.

Abstract: An automatic call generator is connectable with the main distribution frame of a common control telephone system and monitors the operation of the system. To this end, the automatic call generator is connected to dedicated line and trunk circuit ports and attempts to place calls from one dedicated spot to another. If the system fails to terminate a call within a prescribed period of time, a malfunction is noted. Two malfunctions within a prescribed set of programs for monitoring the system cause a system alarm to be generated. The call generator also tests itself after proceeding through assigned programs for monitoring the system.

Abstract: Digit analysis within an electronic private automatic branch exchange telephone system is carried out through interconnected sections of digit decoder circuitry. A first portion of the digit decoder effectively processes dialed impulses originating within the PBX system and determines whether or not the call is to be directed to another line within the system, to a trunk or to the attendant. The contents of an ING and ED memory are continuously monitored and modified, where necessary on a time shared basis with the other calls processed by the system. Direct inward dialing and listed directory number analysis is carried out in a second portion of the decoder which also causes the ING and ED memory to be monitored and modified, where necessary for the processing of the digits. For either internally directed or externally directed calls, the sequentially received digits are initially processed in the units position of the memory and appropriate action is taken as the result thereof.

Abstract: A number translator which includes a memory system for storing directory and equipment numbers as well as other subscriber data has a digit store for storing data received from a register prior to its being passed on to the memory system, a register sender control for controlling the sending of data from the memory system to the register and a translator control for controlling both the digit storage and the sender control. The number translator further includes a route translation circuit by which an available outgoing trunk group is selected and an outgoing trunk marker control for controlling trunk selection based on sender availability. Various decoding is also performed in the translator including both calling and called class-of-service decoding as well as office codes and party line identification.

Abstract: A container assembly for a telephone repeater or the like including a circular flat base of metal and a dome-like cover of plastic. The cover includes an outwardly extending, flared flange for engagement against a chamfered outer edge portion of the base. The flange is secured to the base by a V-groove ring, one wall of which defines, in conjunction with the chamfer of the base, an outwardly flared annular chamber for receiving the flared flange. An O-ring is seated in a groove in the chamfer of the base in pressure engagement against the flared flange of the cover.The arrangement maintains an air tight seal between the cover and the base over a wide range of temperatures despite a difference between the thermal expansion characteristics of the metallic base and the plastic cover.

Abstract: A timer circuit receives a multi-bit digital signal representative of a timing code to be incremented. In dependence upon the coded value of the received signal, the code represented by the signal will be incremented at a selected clock rate. The clock rate selected may be chosen to decrease in frequency in a stepwise manner as the code is incremented. As the timing interval increases, the percent resolution of the timing code is maintained substantially constant.

Abstract: A trunk adapter is associated with a common control private automatic branch exchange telephone system for interfacing the system with a central office. Four different types of adapters are associated with the system to effect a ring-down incoming, loop start outgoing trunk connection, a ground start type trunk connection, a two-way dial-to-dial trunk connection, and a two-way E and M signalling interface. To provide a buffer between the ring and tip circuits the adapters employ optical coupler circuits. The adapters are controlled by the common control on a time shared basis and operate independently of the state of the sleeve lead.

Abstract: The subject of the disclosure is low-pass filter apparatus for use in filtering out noise in a signal channel for propagating PAM signals. A sample and hold circuit which operates in synchronism with the presence of PAM pulses is provided as the input section. The output of the sample and hold circuit is applied to a four-pole, low-pass, RC active filter network. An adjustment is made to the active filter network such that the filter network's low frequency complex pole pair is changed to provide compensation for an undesired roll-off of band pass in the intended in-band region due to the frequency response characteristics of the sample and hold circuit. The resultant apparatus provides a significant reduction in active filter gain required for a given PAM duty cycle. It also provides increased noise rejection capability in the out-of-band region of operation.

Abstract: An electronic private automatic branch exchange may avoid the need for access trunks and information trunks in the operator complex by utilizing a single stage switching matrix to effect connections between line circuits, trunk circuits, and the operator under control of the common control. To accomplish this the operator line circuits are provided and operator loop circuits as line appearances at the inputs of the matrix. In addition, the common control is provided with recognition circuitry for recognizing a request from a line for connection to the operator or a request by the operator for connection to a line and conversion circuitry for converting such requests to a multidigit designation of the operator line circuit or loop circuit to be acted upon by the system in the manner of a connection of a line circuit.

Abstract: A digital interface especially useful for isolating a speedily responsive circuit from the effects of transients at its input such as may be caused, for example, by contact bounce in a relay. The circuit includes a monostable multivibrator connected to be set in response to changes of alternately opposite polarity of the input signal and having a characteristic period equal to a predetermined fraction of the normal minimum interval between intended changes of the input signal. The output of the multivibrator is used to drive a flip-flop at the end of the characteristic period to produce the desired output signal. Thus, the circuit is non-responsive to relatively rapid alternations of the input signal immediately following a change of its condition, yet responds reliably when the input signal changes state and remains stable in its new state for a time exceeding the characteristic period of the multivibrator.

Abstract: A circuit for detecting a true seizure condition of a trunk calling bridge relay employs a timer which is incremented every 40 milliseconds as long as a continuous trunk off-hook representative signal is supplied thereto for approximately 300 milliseconds. For momentary changes in the condition of the trunk CB relay the timer will be incremented and decremented so as to effectively filter out momentary trunk calling bridge seizure changes.

Abstract: A scanner arrangement for scanning both line circuits and incoming trunk circuits simultaneously in groups with priority being given to the scanning of incoming trunk circuits. A sequencing means provides for individual scanning of line circuits of respective groups in which a possible request for service exists and the priority for trunk circuits is effected by inhibiting this sequencing and immediately scanning a selected group of trunk circuits.

Abstract: A telephone transmission bridge including a transformer having primary and secondary windings, connected between first and second input leads and first and second output leads, respectively, has a varistor connected in series with a relatively small number of tertiary windings wound around the transformer core. The tertiary windings and varistor present a high AC impedance to signals transmitted via the input and output leads, thereby permitting AC signals to be transmitted freely via the primary and secondary windings. When transient DC signals are impressed on the input and output leads the tertiary windings and varistor exhibit a low DC impedance, the varistor conducts effectively short circuiting the primary or secondary windings to which the transient signals are transmitted and the transient signals are prevented from being transmitted through the transmission bridge.

Abstract: A call queue release control circuit for automatic toll switchboards is disclosed. The call queue release control circuit is supervised by a plurality of multi-position switches that are set in accordance with decisions made at a chief operator position as to the number of different types of calls to be released in an allocation chain. Individual numbers of calls to be released are loaded through guarded inputs into separate presettable counter circuits associated with the type of call to be released. A sequencing circuit addresses the plurality of counter circuits in succession to form the allocation chain. As a particular counter circuit is addressed, the sequencing circuit provides an enabling signal to a call queue control circuit for releasing the type of call associated therewith and receives from the call queue control circuit a confirmation signal for every call released.

Abstract: A method of service code conversion and a service code conversion control circuit are disclosed for translating a dialed service access code in an abbreviated form into the directory number of a line circuit. A class-of-service indication assigned to a calling line circuit and a dialed abbreviated service access code are steered from a common register to a first translation circuit normally providing outgoing routing information for trunk marking. Instead of providing outgoing routing information, the first translation circuit or translator is strapped to recognize the class-of-service indicator and abbreviated dialed access code to enable a service code conversion control circuit. The service code conversion control directs the first translator to perform a conversion of the access code to a type of call indicator and a directory number, both of which are returned to the common register.

Abstract: An arrangement is disclosed for providing trunk consultation in an electronic private automatic branch exchange which is built around a space divided solid state matrix. The trunk consultation arrangement is enabled by a hookswitch flash from a consulting PABX station connected to an established incoming or outgoing trunk call and directs the trunk junctor associated with that call to place the connected trunk on hold. While the connected trunk junctor is in a held status, the consulting PABX station is forwarded to a local junctor where the consulted trunk party is dialed. A connection between the consulting PABX station and the consulted trunk party is then established via a second trunk junctor. Further circuitry is provided in the trunk consultation arrangement to establish a three-way consultation between the consulting PABX station, the consulted trunk party, and the held trunk party.

Abstract: An improved loudspeaking telephone system including voice switching is disclosed. The system is bistably voice controlled by inversely regulating the impedances of variolossers in the transmit and receive channels, respectively. Hysteresis is added to the bistable control by the summation of receive and transmit signals across a plurality of unequal impedances that form part of an input control means. Circuitry forming the input control means also includes transmit noise guard circuit means useful in discriminating between ambient noise signals and syllabic speech signals. Further, a novel receive noise guard circuit means is used to discriminate between syllabic speech signals and high level noise transmissions from another station. The outputs of both the transmit and the receive noise guard circuit means are summed with the transmit and receive signals across unequal impedances to prevent seizure of the bistable control by ambient noise and to improve the receive channel sensitivity.

Abstract: Apparatus and method for the uniform dipensing of a conductive epoxy binder in hybrid microcircuit applications. A method is disclosed of uniformly pressurizing a conductive epoxy binder through a small orifice until a droplet of fixed volume forms, setting a predetermined gap size between a contact pad and the droplet in order to control the shape and size of the epoxy droplet left on the pad as the droplet touches it, and then releasing the pressure while reciprocating the dispenser from the pad. Also, apparatus, including a cylindrical limiting means attached to the dispenser tip, is disclosed for ensuring the gap size is constant. Other embodiments of the limiting means provide for the use of a relieved section which assists in preventing contamination and for adjusting means operable to vary the gap size.

Abstract: In an electronic private automatic branch exchange telephone system, busy test is carried out by way of a two step process. Initially, a junctor memory is scanned and the called number is compared with each ING and ED number contained in memory. At the completion of the scan and comparison a check of the calling bridge relay of the called number is made. Associated with the busy test arrangement are camp-on and call-waiting features which may also be carried out during the test.

Abstract: A universal answer arrangement for a PABX in which incoming trunk calls are automatically connected, when all operator positions are busy or unattended and equipped for universal answer service, to a pre-designated line circuit or, at night, to one or more selected operator position circuits. In response to the connection to an associated operator loop circuit, a programmable automatic dialing circuit transmits a programmable predetermined number to a local register which effects a switch-through from the incoming trunk to the designated line circuit. The operator loop circuit monitors the connection and releases from the call when the called line goes off hook. Advantageously, the night answer arrangement includes a PABX group hunting circuit which permits the incoming call to be connected to a second line circuit if the first line circuit is busy or to a tie line trunk to another PABX having a night attendant if all line circuits in the hunting group are busy or disabled.