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:
Aug. 04, 1987
Filed:
Sep. 03, 1985
John Ma, Milpitas, CA (US);
Steven Weiss, Las Gatos, CA (US);
Capetronic (BSR) Ltd., Kowloon, HK;
Abstract
An improved system is provided for accurately referencing the revolving motion of electric motors used as positioning devices, and is particularly applicable to the automatic positioning and repositioning of ground station antennas in the reception of satellite TV signals. The system utilizes the action of the positioning motor itself as a reference and involves the extraction and counting of variations in the form of pulses produced in the current within the motor as a result of pulses generated, during motor operation, by the commutation process. A low impedance source senses the motor current pulses and feeds them to an active lowpass filter which suppresses any high frequency noise produced during motor commutation. Peak following circuitry, including separate positive and negative peak detectors, detects and follows the positive and negative peaks of the motor current pulses and produces a pulsating output waveform which is proportional to the number of motor current pulses detected by the peak detectors. The output pulses can be counted to provide an accurate referencing of the motor revolving motion with improved resolution and reduced susceptibility to measurement errors.