Starting-current limiting device for single-phase induction motors used in household electrical equipment
US5164651A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 1991 |
| Grant date | Nov 17, 1992 |
| Priority date | — |
| Expiry date | Jul 3, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02P1/42
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Disclosed is a starting current limiting device for single-phase induction motors, driven by an AC power supply, used in household electrical equipment. The device is adapted to provide, as the power switch of the induction motor is just turned on, a low and gradually increasing starting current flowing into the induction motor. The device is capable of cutting some portions of each cycle in the waveform of the AC power off such that the average voltage input to the single-phase induction motor is reduced, and/or converting some portions of each cycle to oscillate in the reverse directions such that the waveform of the AC power input to the single-phase induction motor appears to have a lower frequency. The device is provided with a switching circuit including a plurality of thyristors, which can be silicon controlled rectifiers or triacs. A means is provided for generating the triggering signals to fire the thyristors, the triggering signals being predetermined and their timing is controlled by a sequence of timing signals. The sequence of timing signals is generated by a timing signal generator capable of generating a single timing signal every time the AC voltage has a zero-cros…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.