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:
Feb. 21, 1989
Filed:
Jun. 18, 1987
Yuichiro Nagato, Chiba, JP;
Hiroshi Hujii, Chiba, JP;
Osamu Matsumoto, Chiba, JP;
Katsuhiko Saito, Funabashi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A hermetic box contains a motor and a self reset type protector which interrupts the supply of electric power to the motor when an abnormally heated condition takes place in the hermetic box and automatically supplies again the electric power when the abnormally heated condition ceases. The motor is energized by an inverter having AC output terminals connected to the motor outside of the hermetic box. A current detector which detects that no current is flowing into the motor is provided on the output side of the inverter outside for a hermetic box. Provision is further made of speed settor for setting the speed of the motor, a lump circuit which receives the output of the speed setting and produces a signal obtained by loosening the sudden change of the output of the speed setting, inverter output control which so controls the inverter that it produces an output voltage and an output frequency depending upon the output of the lump circuit, and a reset circuit which decreases the output of the lump circuit when the current detector has detected that no current is flowing into the motor.