Apparatus for detecting the speed of an electric motor
US4227129A · kind A · utility
7Cited by
3References
12Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jan 29, 1979 |
| Grant date | Oct 7, 1980 |
| Priority date | — |
| Expiry date | Jan 29, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S388/934
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Apparatus for detecting the speed of an electric motor that forms part of a web transport system employs a bridge circuit adapted to measure the back emf of the motor. Thermally induced changes to the armature resistance of the motor are compensated for by varying the bridge resistances, such changes being identified by comparing the bridge circuit signal output with a reference signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.