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:
Jun. 13, 1995
Filed:
Nov. 12, 1992
Paul Gmeiner, Lieli, CH;
Sten Schmidt, Schlieren, CH;
Micafil AG, Zurich, CH;
Abstract
The method and the device for carrying out the method are used for producing transformers (27, 28, 29) which are filled with insulating means, especially transformers for distribution systems. In the case of the method, solid insulation of the transformers is dried in the device before addition of an insulating means, in that the low-voltage windings are short-circuited in every transformer, and the parallel-connected high-voltage windings (30, 31, 32) are heated by means of a low-frequency AC current. In this case, the mean temperature of the windings of the transformers is determined at the same time by measuring the low-frequency AC current, in order thus to make it possible to dry the solid insulation well. In carrying out the method, the mean temperature of the high-voltage windings (for example 31) of each transformer (for example 28) is determined independently of the mean temperature of the windings of each transformer, preferably additionally, by means of a resistance measuring apparatus (14) which is connected in series with the at least one part of the high-voltage windings (for example 31). As a result of suitable guidance of the low-frequency AC current and/or switching of the resistance measuring apparatus (14), the mean temperatures of the high-voltage windings (for example 28) and of the low-voltage windings of one of the transformers (for example 31) can be determined, and the other transformers (for example 30, 32) can be heated further at the same time.