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:
Mar. 24, 1998
Filed:
Feb. 12, 1997
Masahiro Inaniwa, Hitachinaka, JP;
Nobuharu Kido, Hitachinaka, JP;
Takahiro Fujimaki, Hitachinaka, JP;
Shinji Watanabe, Hitachinaka, JP;
Noriyasu Matsufuji, Hitachinaka, JP;
Yoshinori Tobita, Hitachinaka, JP;
Hitachi Koki Co., Ltd., Tokyo, JP;
Abstract
A power control apparatus for controlling power supplied to an electric motor rotating a rotor employed in a centrifuge is provided. The power control apparatus includes first and second inverters and a smoothing capacitor disposed between the first and second inverters. In a motor power mode, the first inverter charges the smoothing capacitor with power supplied by an AC power supply, while the second inverter charges, in a motor braking mode, the smoothing capacitor with power regenerated by the motor during a braking operation for returning the regenerated power back to the AC power supply through the first inverter. An reactor is arranged between the AC power supply and the first inverter for reducing harmonic components contained in the current supplied from or back to the AC power supply.