Abstract: The synchronized clock receives a plurality of external synchronization signals and includes a servo-control signal generator in association with each of said external synchronization signals. The synchronized clock also includes a control unit which produces the control signal actually applied to a clock generator by selecting a particular one of the servo-control signals on the basis of quality criteria.

Abstract: In an installation for conveying delicate objects such as semiconductor layers during processing operations and for handling such objects in a controlled atmosphere, wheeled carriages are drawn along tracks by an endless belt and are not driven by motors in order to satisfy conditions of cleanliness and freedom from pollution hazards. By means of transfer tools, object-holding cassettes are taken from the carriages during operation and replaced on the carriages after processing in the different machines.

Abstract: A timebase adapted to be synchronized to an external clock comprises at least one generator incorporating a voltage-controlled oscillator adapted to be controlled by the result of comparing an external synchronization signal from an external clock with an output signal of the timebase. Each generator comprises at least one differential comparator receiving the external synchronization signal and the timebase output signal. It drives a summing circuit on the input side of the control input of the oscillator of the generator in question. The generator further comprises a calibration system comprising a threshold detector connected to the output of the phase comparator, a calibration voltage adjustment circuit connected between the threshold detector and a second input of the summing circuit, and a trigger circuit in and controlling the adjustment circuit.

Abstract: A relay matrix which constitutes an array of switches providing connection points between a set of "horizontal" inputs and a set of "vertical" outputs, has n relays per column disposed in p columns. Each relay column is associated with a register which fulfills the functions of controlling and storing the state of the relays of the column. The invention can be applied to switching systems and in particular to automatic telecommunication exchanges.