Deutsche Thomson-brandt Gmbh

Dual Gebruder Steidinger Gmbh & Co.

Rudiger Lehmann

Gunter Gleim

Dietmar Uhde

Hartmut Schandl

Peter Hoch

A drum for a rotatable cylinder head includes an opaque disc-shaped member having a plurality of opaque fins affixed thereto and arranged substantially normal to the disc-shaped member. A first plurality of the fins has a first width and a second plurality of the fins has a second width broader than the first width. Every fin has a distal end remote from the disc-shaped member, and an opaque circumferential ring is affixed to the distal end of each fin. The disc-shaped member, the fins and the circumferential ring form a plurality of apertures about the drum.

Head cylinder for a recorder

A brushless DC motor system includes a multi-pole DC motor having coils and permanent magnets. Optically scannable markers are applied on the circumference of a rotating member of the motor in fixed association with the magnets. By means of a scanner, these markers are converted to signals. These signals are evaluated with respect to their phase position and moment of commutation, and as a result commutation current is supplied to the coils.

Brushless DC motor system with optically scannable member for commutation

A switch device for a turntable with a starting device which closes the switch for the drive motor on the one hand by means of a swinging movement of the pick-up arm manually during swinging-in from its support bracket onto the record, and on the other hand by means of a direct current dc low voltage solenoid which is actuated by momentary actuation of an operating service element, the latter being connected with a first contact pair, and a switch-off device which acts automatically with the arriving of the pick-up or reproducing head in the run-out groove of the record, the switch-off device opening the switch for the drive motor and containing a switch for the entire current supply of the device from the power supply mains. In a per se known manner a common main switch lies in the circuit for the drive motor and the other current supply of the device, and a second contact pair is connected with the operating element for starting the device such that it opens and closes in the same direction with said first contact pair for the solenoid and is connected parallel to the main switch.

Growing community of inventors

St. Georgen, Germany

Rudiger Lehmann