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. 04, 1989
Filed:
Nov. 19, 1987
Suzuo Saito, Tokyo, JP;
Shigetoshi Higaki, Tokyo, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A security apparatus adapted to a power converter, including a power converting circuit connected between a DC power source and an AC system; a phase detector circuit for detecting the voltage phase of the AC system to provide a phase detection signal; a reference signal generator circuit for generating a voltage reference in accordance with the phase detection signal; a control circuit for controlling an output voltage of the power converting circuit in accordance with the voltage reference. The security apparatus is characterized by a disturbance generator circuit for applying a disturbance to the phase detector circuit; and a detector circuit for detecting an abnormal state in which the phase or frequency of the output voltage of the power converting circuit deviates from a normal one.