Abstract: In the arrangement disclosed, a photoconductive cell has electrical characteristics which depend upon its optical exposure. An optical system focuses an image upon the cell. An electrical system utilizes the output of the cell on the basis of the light upon the cell. The cell includes a multiplicity of photoconductive portions forming at least one row transverse to the direction of image intensity changes so that different portion sense different intensities. The electrical means are connected to a plurality of the portions. The portions may be formed into an elongated integral strip whose direction changes and whose edges are insulated from each other. Alternately the portions may be connected electrically to form a continuous electrical strip. The strip may have a spiral shape. In one embodiment the portions are connected together to form an AND or OR gate. Two identical cells may straddle a desired image plane and be subject to the same image.

Abstract: An arrangement for synchronizing a mechanical oscillating system to the accuracy of a quartz standard, in particular the timing of a clock. Timing pulses are derived from a quartz oscillation, and these act on the frequency of the oscillating system. An "existing value" signal is derived from the oscillating system, and frequency deviations of the existing value signal from the timing pulses are detected by a phase comparison. The frequency of the mechanical oscillating system is processed in accordance with the deviations that are detected.

Abstract: In the arrangement disclosed, a photoconductive cell has electrical characteristics which depend upon its optical exposure. An optical system focuses an image upon the cell. An electrical system utilizes the output of the cell on the basis of the light upon the cell. The cell includes a multiplicity of photoconductive portions forming at least one row transverse to the direction of image intensity changes so that different portion sense different intensities. The electrical means are connected to a plurality of the portions. The portions may be formed into an elongated integral strip whose direction changes and whose edges are insulated from each other. Alternately the portions may be connected electrically to form a continuous electrical strip. The strip may have a spiral shape. In one embodiment the portions are connected together to form an AND or OR gate. Two identical cells may straddle a desired image plane and be subject to the same image.

Abstract: One bifilarly deposited photosensitive strip provided with electrodes on the ends, and a second bifilarly deposited photosensitive strip, contacted along its long edges by two electrodes, are disposed on opposite side of a transparent spacer to form a focusing indicator. When one or more indicators are mounted at suitable locations in an optical system, suitable circuit means respond to the electrical output at the electrodes and respond to the optical system position. Indication may be accomplished by responding to the circuit means.

Abstract: A technique of synchronizing an oscillating system driven by a mechanical energy storage means, particularly a timepiece having a regulating member which is set and maintained in oscillation by a pulse-like driving moment and which is synchronized by electromechanical action by means of timing pulses derived by division from a quartz oscillation, characterised in that the synchronizing action is achieved through an electromagnetic coupling or electromotively through indirect synchronization, in which a phase and frequency comparison is made between said timing pulses and an alternating voltage signal derived from the movement of the oscillating system, for example of the balance, with the oscillating system of corresponding frequency and phase, while in addition a regulating signal is derived from the comparison and is utilized to produce a torque M.sub.R which through the electromagnetic coupling applies a regulating action to the oscillating system.

Abstract: A large-sized clockwork comprising movement, a striking train, an electrical drive mechanism for the striking train, and a control section for the striking train which includes a first control element for actuation of the striking train and a second control element for limiting the striking period thereof. The two control elements include control portions which are each adapted to be sensed by a substantially reaction-free electrical sensing device, which is superordinated to the striking train drive device. Depending upon the choice of the sensing means, the control section has only negligibly small power requirements. Consequently, no restrictions which would be dictated by the control section, now exist in the selection of the movement system.