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. 08, 2011
Filed:
Nov. 28, 2008
Yasusuke Iwashita, Yamanashi, JP;
Tadashi Okita, Yamanashi, JP;
Hiroyuki Kawamura, Yamanashi, JP;
Kenichi Takayama, Yamanashi, JP;
Yasusuke Iwashita, Yamanashi, JP;
Tadashi Okita, Yamanashi, JP;
Hiroyuki Kawamura, Yamanashi, JP;
Kenichi Takayama, Yamanashi, JP;
Fanuc Ltd, Minamitsuru-gun, JP;
Abstract
A motor drive includes a dynamic braking circuit for producing a deceleration torque utilizing a braking force caused by a synchronous motor acting as a generator when the synchronous motor is deenergized. The motor drive apparatus is equipped with a dynamic braking circuit fault detection capability, a DC power supply which is obtained by rectifying input AC power, voltage application function for applying a voltage to the windings of the synchronous motor and to the dynamic braking circuit for a predetermined length of time by switching power transistors connected to the DC power supply, current detection unit for detecting the value of a current flowing from the power transistors, and fault checking unit for checking the dynamic braking circuit for the presence or absence of a fault, based on the current value detected by the current detection unit and on a predefined threshold value.