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:
Apr. 30, 2013
Filed:
Mar. 02, 2011
Applicants:
Tomoyuki Furuta, Yamanashi, JP;
Akiyoshi Kawahara, Yamanashi, JP;
Masao Murai, Yamanashi, JP;
Inventors:
Assignee:
Fanuc Corporation, , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02P 7/00 (2006.01); B23H 7/00 (2006.01); G05B 11/28 (2006.01);
U.S. Cl.
CPC ...
Abstract
In a torque motor driving device for wire cut electrical discharge machines, a voltage waveform rectified by a full-wave rectifying circuit, not using a high-capacitance electrolytic capacitor, is applied as an AC voltage to a single-phase torque motor by a bridge circuit including semiconductor switches. A PWM signal whose duty is adjusted so that the current flowing through the torque motor matches an instructed value is generated and the generated PWM signal is used for the operation of the bridge circuit.