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:
Jul. 21, 1992
Filed:
Oct. 02, 1990
Gary C Jorgensen, Phoenix, AZ (US);
Michael D Harper, Phoenix, AZ (US);
Calsonic International, Inc., Irvine, CA (US);
Abstract
A method and apparatus for accurately and reliably positioning an actuator arm (12) is disclosed. The actuator arm (12) is driven by a conventional DC motor (38). The conductors which supply current to the motor (38) serve as primary windings (60) of a current transformer (58). The signal induced on secondary windings (62) of the transformer (58) responds to fluctuations in average current flowing in the motor (38). These fluctuations are amplified (64) and filtered (66) so that an AC burst (68) is produced in response to each commutation of the motor (38). The AC burst (68) triggers a one-shot timing circuit (72), which generates a pulse that remains active until the AC burst (68) has decayed. The pulse disappears prior to a subsequent commutation of the motor (38). Thus, one pulse is generated for each commutation of motor (38). A counter (76) is clocked by these pulses. The counter (76) increments when the motor (38) moves in one direction and decrements when the motor (38) moves in the opposing direction. Thus, the counter (76) maintains a current count which describes the position of the motor (38). A controller (16) compares this current count with an input signal (14) and controls the operation of the motor (38) based on the results of the comparison. Accordingly, the motor (38) moves until the current count reaches a value corresponding to information presented in the input signal (14).