Abstract: A router has N1 local signal input terminals for connection to respective local signal sources for supplying respective local input signals, a local output interface including M1 local signal output terminals, and an input expansion terminal. A signal received at any one of the N1 local signal input terminals can be routed selectively to any one or more of the M1 local signal output terminals and a signal received at the input expansion terminal can be routed selectively to any one or more of the M1 local signal output terminals. An input signal received at a local signal input terminal is delayed relative to an input signal received at the input expansion terminal by a selectively adjustable amount to achieve a predetermined time relationship between the input signals at the local output interface.

Abstract: A guide insert is provided for engagement with an edge connector receptacle including a housing having an insertion face and defining a slot for receiving a card edge inserted into the slot along an insertion axis. The guide insert has a body portion that fits over the insertion face of the housing and is formed with first and second aligned slot-form apertures for providing access to first and second segments respectively of the slot defined by the housing. A tab projects from the body portion of the guide insert between the first and second apertures for entering the slot when the body portion engages the insertion face of the housing. The tab has two opposite faces presented towards two opposite sides respectively of the slot.

Abstract: First and second successions of data words, each data word including multiple payload data bits, a data block bit (C) and a block character (SOB) having a first state to indicate start of a sequence of data block bits and otherwise having a second state, are processed by detecting as a first event occurrence of the block character of the first succession of data words in the first state and as a second event the next succeeding occurrence of the block character of the second succession of data words in the first state, wherein the second event is delayed by a time Tz relative to the first event, reading the data block bits from successive data words of the first succession and generating a succession of delayed data block bits of the first succession of data words, delayed by the time Tz relative to the payload data bits of the first succession of data words.

Abstract: Audio data of at least two audio data groups is embedded in an ancillary data space of a serial digital video data stream by multiplexing the audio data groups to provide a serial multi-group audio data stream, and inserting the serial multi-group audio data stream into the ancillary data space of the serial digital video data stream.

Abstract: A routing switch includes a first router module having N1 signal input terminals, M1 signal output terminals, an expansion input terminal and an expansion output terminal and including a core for routing a signal received at any one of the N1 signal input terminals selectively to any one or more of the output terminals and for routing a signal received at the expansion input terminal selectively to any one or more of the N1 signal output terminals. The router further includes a second router module having N2 signal input terminals, M2 signal output terminals, an expansion input terminal and an expansion output terminal and including a core for routing a signal received at any one of the N2 signal input terminals selectively to any one or more of the output terminals and for routing a signal received at the expansion input terminal selectively to any one or more of the M2 signal output terminals.

Abstract: A router that utilizes one additional crosspoint module to provide backup to N crosspoint modules. The redundant crosspoint module receives every input from P input modules and provides O/N outputs to M output modules. Each of the M output modules receives an output from a particular N crosspoint module and a corresponding O/M output from the redundant crosspoint module. Each output module has logic to determine whether the output module should select the output from a particular N crosspoint module or the output of the redundant crosspoint module.

Abstract: Electronic equipment includes a frame having a wall and connectors attached to the wall of the frame. A main board has a connection edge at which it is provided with connectors for engaging the connectors that are attached to the wall of the frame when the main board is advanced relative to the frame along a connection axis. An edge connector receptacle is attached to the wall of the frame and defines a slot perpendicular to the connection axis and to the connection edge of the main board. An auxiliary board is attached to the main board and is oriented perpendicular to the main board and parallel to the connection axis. The auxiliary board has a connection edge perpendicular to the connection edge of the main board and positioned to enter the slot of the edge connector receptacle concurrently with engagement of the connectors at the connection edge of the main board with the connectors attached to the wall of the frame.

Abstract: A circuit for processing a differential serial digital data signal provided by a signal source includes a transmission line and an amplifier. A first capacitor couples a first conductor of the transmission line to a first input of the amplifier and a second capacitor couples a second conductor of the transmission line to a second input of the amplifier, and a termination resistor is connected between the first and second inputs of the amplifier. The capacitance value of the first capacitor is such that the time constant of the first capacitor and the termination resistor is about one-third of one bit time of the serial digital data signal and the capacitance value of the second capacitor is substantially greater than the capacitance value of the first capacitor.

Abstract: Apparatus for determining nominal pulse duration values in a signal encoded with an AES3 data stream includes a first circuit for measuring duration of each pulse of the signal and providing a sequence of duration values. A second circuit detects a maximum duration value, corresponding to duration of three bit cells, and provides first and second duration values corresponding to one bit cell and two bit cells respectively.

Abstract: An optoelectric converter for generating a binary electrical data signal from a binary optical data signal includes a semiconductor photodetector for receiving the optical data signal and generating an electrical current signal. An amplifier receives the current signal generated by the semiconductor photodetector and providing a voltage output signal. An equalizer receives the voltage signal generated by the amplifier and generates an equalizer output voltage signal. A DC restorer receives the equalizer output voltage signal and generates a DC restored voltage signal.

Abstract: In a video broadcast or production plant including first and second video sources which provide first and second digital video signals respectively at integer related frame rates, the video sources are operated so that the first and second video signals are aligned at a reference time. Switch points for updating a router in the plant are defined by measuring lapse of time from the reference time.

Abstract: A mother board is mounted in an electrical equipment frame and has the receptacle of a first connector attached thereto at one face. The plug of the first connector is attached to a daughter board at an interconnect edge so that the first connector can be engaged by movement of the daughter board toward the mother board along an axis perpendicular to the interconnect edge of the daughter board and to the face of the mother board. A mezzanine assembly is attached to the daughter board and includes a mezzanine board in spaced parallel relationship with the daughter board and having an edge which is substantially parallel to the interconnect edge of the daughter board and at which the receptacle of a second connector is attached to the mezzanine board. An interconnect board is mounted in the frame and has an edge at which the plug of the second connector is attached to the interconnect board.

Abstract: An automatic power control circuit for a laser driver which is responsive to a data signal for driving a laser diode includes a low pass filter connected to receive the data signal and generate an output signal dependent on the DC content of the data signal. A circuit responsive to both an externally provided average power control signal and the output signal of the low pass filter controls supply of operating current to the laser diode.

Abstract: An interconnection arrangement includes an input card, a signal distribution board having first and second opposite main faces, and an input connector having first and second releasably engageable parts with the first part of the input connector attached to the signal distribution board at the first main face thereof and the second part of the input connector attached to the input card. A bus driver circuit is mounted on the input card and has a signal input terminal for receiving an input signal to be distributed. The bus driver circuit includes first and second bus drivers. The first and second bus drivers each have an input connected to the signal input terminal of the bus driver circuit and they have separate respective outputs connected to first and second pins respectively of the second part of the input connector.

Abstract: A transceiver includes a first receiver having an input connected to a first I/O port of the transceiver and an output connected to an output port of the transceiver and a second receiver having an input connected to a second I/O port of the transceiver and an output connected to the output port of the transceiver. A first driver has an input connected to an input port of the transceiver and an output connected to the first I/O port, and a second driver has an input connected to the input port of the transceiver and an output connected to the second I/O port.

Abstract: A snap-on guide for assisting engagement of a push-on BNC plug with a BNC receptacle has a sleeve adapted to fit over the barrel of the receptacle. The sleeve is formed at one end with two diametrically opposed slots for receiving respective bayonet pins of the receptacle, the slots being configured for engaging the bayonet pins in a manner that tends to retain the sleeve on the barrel against a force tending to remove the sleeve from the barrel. The guide has an extension with an interior surface which flares outward from the sleeve at its opposite end from the slots for receiving and guiding engagement of the plug.

Abstract: A crosspoint switch having M input terminals and N output terminals has (M/m) times (N/n) crosspoint switch modules each having m input conductors and n output conductors. (M/m) of the crosspoint switch modules have their input conductors connected to the M input terminals respectively of the crosspoint switch, and (N/n) of the modules have their output conductors connected to the N output terminals respectively of the crosspoint switch. The input conductors of the first module are connected to respective input conductors of a second module and the output conductors of the first module are connected to respective output conductors of a third module.

Abstract: A switch comprises n I/O ports, where n>2, and a switching core having n inputs connected to the n I/O ports respectively and n outputs connected to the n I/O ports respectively and comprising means operable to connect the ith input, where 1.ltoreq.i.ltoreq.n, to at least the jth output, where 1.ltoreq.j.ltoreq.n and j.notident.i.

Abstract: An oscillator comprises a first inverter provided with a resonant feedback circuit, a second inverter having its signal input terminal at the same DC level as the signal input terminal of the first inverter, and a current source having a current supply terminal connected to the power supply terminals of the first and second inverters.

Abstract: A circuit for processing an input pulse signal of which the slew rate is dependent on pulse frequency comprises an amplifier (30; 78) for receiving the input pulse signal and generating an output pulse signal having transitions of which the slew rate is dependent on a bias current supplied to the amplifier, and a circuit (38-66; 82-108) for supplying bias current to the amplifier, the bias current being representative at least substantially of the frequency of occurrence of pulses in the input pulse signal.