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:
Dec. 31, 1985
Filed:
Oct. 03, 1984
Masahiro Tobise, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a static leonard apparatus, a DC motor is supplied from a thyristor converter through a main circuit switch, and a capacitor is connected between the DC output buses of the thyristor converter. When the main circuit switch is turned off, a grounding switch is turned on to ground one of the DC output buses to form a grounded closed discharge circuit including the DC motor through which the capacitor discharges. During the turned-off period of the main circuit switch, the capacitor is charged with the output voltage of the thyristor converter. The capacitor discharges through the grounded closed discharge circuit. The voltage values of the discharging capacitor at two points on the time axis are detected to compute the discharge time constant of the capacitor, and, on the basis of the computed discharge time constant, the insulation resistance of the DC motor is measured.