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:
Oct. 15, 1991
Filed:
Feb. 21, 1990
Yukihiko Hatano, Ichinomiya, JP;
Kabushiki Kaisha Toshiba, Kanagawa, JP;
Abstract
An opposite phase detecting device for alternating current electrical equipments includes a zero cross circuit synchronizing positive half waves of first and second line voltages of a three-phase AC supply supplied to an AC electrical equipment and generating first and second synchronizing pulses each having a pulse width corresponding to an electrical angle of approximately 180 degrees, a counter circuit counting the first synchronizing pulses from the zero cross circuit, a one-shot multivibrator triggered by the second synchronizing pulse to thereby generate a reset pulse having a relatively short time interval, and an AND circuit generating a reset signal based on a logical multiplication of the reset pulse generated by the pulse generating circuit and the first synchronizing pulse generated by the synchronous circuit. The counter circuit is reset when supplied with the reset signal from the AND circuit. The counter circuit generates an opposite phase detection signal when the count value thereof reaches a predetermined value.