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:
Nov. 22, 1994
Filed:
Apr. 29, 1993
Shiro Maeda, Kusatsu, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A brushless motor operating apparatus includes a DC power source 1, a group 2 of semiconductor switching elements for passing/interrupting a current to an armature winding 4 of a brushless motor 3, a plurality of filter circuits 6 for waveform-processing induced voltages induced in the armature winding 4, a comparison circuit 7 for comparing outputs of the plurality of filter circuits 6 and a composite wave thereof, a control circuit 8 for making ON/OFF control of the semiconductor switching element group 2 in accordance with an output of the comparison circuit 7, the filter circuit 6 having a construction in which condensers 6c and 6e are connected behind and in series with a voltage divider circuit composed of a plurality of resistors 6a and 6b and an integrating circuit 6d is connected behind the condensers 6c and 6e, whereby the condensers 6c and 6e in the filter circuit 6 can be provided with ones having a low withstanding voltage, thereby making it possible to reduce the size and cost of the apparatus.