Plessey Handel Und Investments A.g.

Other

John P Wren

Ian W Buckner

Anthony Thomas Lambert

John Fiddian Birtles

Michael Keith Steventon

Signaling means adapted for use on a vehicle, the signaling means being activated in response to a signal from a sensing means, the sensing means being adapted to sense movement of the brake operating part of the driver in a direction likely to result in the brakes associated with that vehicle being applied, such as, for example, movement of the driver's foot from the accelerator pedal towards the brake pedal. The signaling means may comprise a high mounted stop lamp or other light emitting source visible to drivers of following vehicles. The invention enables drivers of such following vehicles to obtain advance warning of potential hazardous situations arising through imminent deceleration of the vehicle in front.

Signalling means for a vehicle

Electrical equipment for controlling an electric motor for the horizontal movement of the pickup member of a disc-record gramophone towards and away from the center of the gramophone turntable comprises position-selector means which, when set to any one of a number of predetermined positions of the pickup member, start the motor and emit a normally constant speed-reference signal controlling the motor speed and, upon receipt of a position-identifying signal from the selected position, cause the motor to be de-energised, thus terminating the motor-driven movement of the pick-up member, individual position-detector means, each so constructed as to perform the dual function of emitting such position-identifying signal and of varying the normally constant reference signal in accordance with the residual distance of the pick-up member from the accurate location of the selected position, thereby varying the motor speed so that the position-detector means work, in conjunction with the motor, as an approach servo.

Electrical control system for the movement of the pickup arm of a

An anti-skating and/or arm-moving device for a disc-record player comprises two permanent-magnet plates carried by the pickup-arm support and each extending over a sector of a circle round the same, the plates being magnetized, each across its thickness, with opposite polarities to produce each a magnetic flux at right angles to the direction of plate movement, and a coil fixed to the player structure in which two conductor elements extend across the flux of each magnet plate respectively, transversely to the direction of magnet movement, and carry the coil current in opposite directions. Current cut-off means are preferably provided for cutting off the anti-bias current in the winding when, particularly during a manual cueing operation, the pickup stylus is lifted from the record surface, and conversely preventing the application of arm-moving current when the stylus rests on a record.

Disc-record players

A motor arranged directly to drive a gramophone turntable which comprises a number of permanent magnet rotor pole pairs arranged on the circumference of a circle centered at the motor shaft, a number of air cored stator windings there being less stator windings than rotor pole pairs, and a commutator arrangement for controlling current through the windings whereby they react with the rotor poles to produce rotation of the turntable the current being controlled so that torque ripple is obviated.

Electric motors

An anti-skating device for a disc-record player comprises two permament-magnet plates carried by the pickup-arm support and each extending over a sector of a circle round the same, the plates being magnetized, each across its thickness, with opposite polarities to produce each a magnetic flux at right angles to the direction of plate movement, and a coil fixed to the player structure in which two conductor elements extend across the flux of each magnet plate respectively, transversely to the direction of magnet movement, and carry the coil current in opposite directions. Current cut-off means are preferably provided to allow the winding to be de-energized when, particularly during a cueing operation, the pickup stylus is lifted from the record surface.

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Swindon, United Kingdom

John P Wren