Electric motor with rotational speed regulation
US4317072A · kind A · utility
Inventors
Key dates
| Filing date | Dec 5, 1979 |
| Grant date | Feb 23, 1982 |
| Priority date | — |
| Expiry date | Dec 5, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P6/08
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Electric motors which are used for instance as driving motors for drilling and cutting implements incorporated in the handle of such implements, are subjected to strongly varying loads. This puts heavy demands to the regulation system of the motor. In a regulation system the signals which are provided by detectors (22) for currently sensing the position of the rotor relative to the stator, are supplied to a pulse generator (44, 46) which provides a pulse frequency being uniquely associated with the period of the varying detector signal. This pulse signal is supplied to a frequency-to-voltage converter (48) which provides an output signal being supplied to a diferential amplifier (50) as one input signal thereof, the other input signal being a reference DC voltage, and the output signal of the amplifier being supplied to a multiplier unit (40, 42) as one input signal thereof, the other input signal being said detector signal. The output signal of the multiplier unit is supplied to the exciting windings (16, 18) of the motor via a power amplifier (54, 56).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.