Controlling electrical phase connections to a three-phase device
US4659974A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1985 |
| Grant date | Apr 21, 1987 |
| Priority date | — |
| Expiry date | Dec 11, 2005 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S323/91
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A control circuit is connected between a three-phase power supply and a motor and ensures the correct application of phase signals to the motor, regardless of the way in which the control circuit is connected to the power supply. A first output signal of the supply is connected directly to an input of the motor via the circuit. Supply of power to the other two inputs is controlled by four switches, two of which receive signals from the second supply output and have their outputs connected to respective motor inputs, and the other two of which receive signals from the third supply output and have their outputs connected to respective motor inputs. The switches are controlled such that two switches are on, and the other two switches are off if the third output signal is positive with respect to the first output signal when the second signal passes through zero with respect to the first signal in a positive sense.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.