Patent · US Expired

Current transformer

US6028422A · kind A · utility

11Cited by
6References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 19, 1999
Grant dateFeb 22, 2000
Priority date
Expiry dateApr 19, 2019

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01F38/32
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A current transformer for mains alternating current with dc components is formed of at least one transformer core with a primary winding and at least one secondary winding, of load resistor is connected in parallel to the secondary winding and terminates the secondary circuit in low-impedance fashion. A semiconductor component that opens during a suitable time span within every cycle and is in turn closed is provided in the secondary circuit. During this time span, the secondary circuit is in a no-load condition. As a result thereof, the build-up of the core magnetization generated by the dc components is collapsed, and thus the transformer core cannot be driven into saturation, so that an over-dimensioning of the transformer cores is unnecessary.

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