Electromagnetic contactor with current regulated electromagnetic coil for holding the contacts closed
US4720761A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1987 |
| Grant date | Jan 19, 1988 |
| Priority date | — |
| Expiry date | Feb 19, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H47/325
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electromagnetic contactor is taught which includes a conduction angle controlled triac or similar gated device which is connected in series circuit relationship with the winding of an electromagnetic solenoid or coil which is responsible for closing the contactor contacts and for keeping them closed. The current flowing through the triac is fed to a microprocessor which digitizes the current and compares it to a stored standard. The conduction angle is then decremented or incremented as necessary to change the conduction angle to cause less or more current to flow per half cycle until the amount of current flowing as sensed on a half-cycle-by-half-cycle basis is equal to the current represented by the stored standard.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.