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:
Sep. 17, 1991
Filed:
Mar. 02, 1990
Applicant:
Inventor:
Guy Geuns, Wuppertal, DE;
Assignee:
Hermann Hemscheidt Maschinenfabrik GmbH & Co., Wuppertal, DE;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H02M / ;
U.S. Cl.
CPC ...
363126 ; 363 52 ; 363125 ; 361 18 ; 361 91 ; 361111 ;
Abstract
An intrinsically safe power supply unit, more particularly for face supports in mining, comprising an ac transformer connected to a rectifier and power resistors for limiting the current and connected to the dc voltage output, wherein the ac voltage transformer is a resonance transformer which stabilizes the secondary voltage, and the dc voltage occurring behind the power resistors is kept constant by three voltage limiters connected in parallel.