Patent · US Expired

Electric current control type variable inductor

US4725805A · kind A · utility

8Cited by
1References
9Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 19, 1986
Grant dateFeb 16, 1988
Priority date
Expiry dateDec 19, 2006

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH01F21/06
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

The construction of cores in an electric-current-controlled type variable inductor used in radio receivers is disclosed. The inductors have three or four cores. In the case of the variable inductors of the type having three cores, the winding portion of a first core is formed with a hollow portion, a second core is inserted into the hollow portion in such a way that the winding portion of the second core can be maintained in parallel with the winding portion of the first core, the first core is inserted into a pot-shaped third core in such a way that the winding portion of the first core can be maintained perpendicular to the bottom of the third core and the magnetic path established by a control coil mounted on the first core and the magnetic path established by a tuning coil mounted on the second core are superimposed one upon another around the winding portion of the second core. According to the present invention, the second core through which is extended the magnetic path established by the tuning coil and a part or means for substantially covering the second core are made of a high-frequency material (or a material best adapted to operate at a high frequency) while the remain…

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