The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 15, 1999
Filed:
Oct. 18, 1996
Peter Mahr, Konigsfeld, DE;
Gerhard Reiner, Villingen-Schwenningen, DE;
Deutsche Thomson-Brandt GmbH, Villingen-Schwenningen, DE;
Abstract
Electronic circuit having a digital controller operation of a synchronous motor. Precision motors for driving, for example, a video head drum in video recorders are normally designed as externally commutated synchronous motors. These motors are driven with square-wave voltages by a digital controller (CON), whose circuitry can easily be implemented. The object of the present invention is to specify an electronic circuit of the type mentioned initially for controlling a synchronous motor, which enables good synchronism and the motor to be operated with little electrical noise. This object is achieved in that the synchronous motor is driven by sinusoidal signals, a separate control signal from the controller (CON) influencing the amplitudes of the drive signals (U1, V1, W1). A regulating signal for regulating the synchronous motor is produced by a sensor (GE) which is arranged on the synchronous motor, which regulating signal produces a fixed phase relationship between rotor revolution and drive signals. The circuit can be implemented in a simple manner and manages without any digital/analogue converters. The applications which result are, in particular, for digital video recorders and for camcorders.