Patent · US Expired

Low noise miniature electric motor

US5262703A · kind A · utility

3Cited by

7References

4Claims

0Family size

Assignee

Papst Licensing GmbH · DE

Inventors

Fritz Schmider · Hornberg, DE
Thomas Von Der Heydt · St. Georgen, DE

Key dates

Filing date	Apr 28, 1992
Grant date	Nov 16, 1993
Priority date	—
Expiry date	Apr 28, 2012

Classification

Technology area (CPC H)Electricity
CPC primaryH02P6/06
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A low noise brushless dc motor has a rotor with a permanent magnet and a stator with a bearing system mounting a shaft for rotating the rotor. The motor has an operating circuit that includes a tachometer winding connected to the base of a first transistor whose collector is in series with a first resistor. The other end of the tachometer winding is connected to the base of a second transistor whose collector is in series with a second resistor.

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