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. 13, 1990
Filed:
Aug. 08, 1988
Kazuhiro Ishii, Fukuyama, JP;
Yoshihiro Hatakeyama, Fukuyama, JP;
Kazushi Sato, Fukuyama, JP;
Akira Takao, Fukuyama, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
When a voltage (V) of a D.C. power source having an internal resistance (5a) exceeds an 'exciting voltage' (FIG. 2), transistors (21, 28 and 33) turn ON, and a transistor (30) turns OFF, and then a tripping winding 16 is excited to close a circuit breaker; on the other hand when the voltage (V) is lowered under a 'tripping voltage', the transistor (33) turns OFF and the transistor (30) turns ON, and thereby a load resistor (31) which is less than a resistance 34 of the tripping winding 16 is connected to the D.C. power source; consequently, the voltage V is further lowered by the internal resistance (5a), and a voltage difference is produced between the exciting voltage and the tripping voltage, thus making a 'hysteresis characteristic' between the exciting voltage and the tripping voltage.