Patent · US Expired

High current high frequency current transformer

US4317979A · kind A · utility

23Cited by
8References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 30, 1980
Grant dateMar 2, 1982
Priority date
Expiry dateMay 30, 2000

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH05B6/06
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

In an induction heating apparatus, direct sensing of the high frequency high power current flowing in the tank circuit to load the induction coils, is obtained with a coil current measuring transformer comprising one of the power current busses leading to the induction coil and a secondary winding of many ampere-turns wound around said one bus. The bus is given a half-loop shape to accommodate the secondary winding. The secondary winding is made of a magnetic core wound with many turns of Litz wire. Cooling tubes are cemented outside the wound secondary with conductive cement to form a heat sink with a circulation of cooling medium through the tube. The cement is divided in two parts separated by gaps to prevent circulation of induced currents. A cooling tube is installed between the core and wound wire to provide an internal heat sink.

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