Contactor control system
US4922363A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1988 |
| Grant date | May 1, 1990 |
| Priority date | — |
| Expiry date | Apr 18, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2047/025
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and apparatus in a control system for an electromagnetic contactor for reducing multiple re-ignitions incorporates a regulated source of electrical power coupled to a contactor actuating coil through a controllable switch. The switch is used to regulate coil current to a desired value whereby opening time of the contactor can be determined within a defined range. Alternating current through tips of the contactor is monitored and each zero crossing of the current wave form is determined. The control system responds to a command to open the contactor tips by coordinating such opening with the zero crossings of the current wave form whereby the contact tips separate within a predetermined phase angle prior to a zero crossing. The system also includes apparatus for detecting a fault current of the alternating current in the contact tips and for inhibiting operation of the contact tips for a predetermined time interval in order to allow fuses to clear the fault prior to opening the contactor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.