Patent · US Expired

Circuit arrangement for limiting the current at make for a transformer

US6094013A · kind A · utility

3Cited by

3References

4Claims

0Family size

Assignee

Siemens Aktiengesellschaft · DE

Inventors

Hugo Goller · Munich, DE
Klaus Hoffmann · Bad Tölz, DE

Key dates

Filing date	Dec 2, 1998
Grant date	Jul 25, 2000
Priority date	—
Expiry date	Dec 2, 2018

Classification

Technology area (CPC H)Electricity
CPC primaryH02H9/002
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A circuit arrangement for limiting the current at make for a transformer wherein, in order to avoid the current peak at make when switching a transformer on, resistors are connected between operating voltage and the primary winding of the transformer. A test winding at the secondary side of the transformer is connected via a rectifier to the supply input of a contactor, so that the switches of the contactor close after the transformer is turned on and the resistors therefore no longer lie between operating voltage of the primary winding. PTC-resistors connected in series with the resistors assure that the resistors are not overloaded by the high-operating current of the transformer if the switches do not switch.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.