Drive circuit for a main contactor
US3940663A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 30, 1975 |
| Grant date | Feb 24, 1976 |
| Priority date | — |
| Expiry date | Jan 30, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/222
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A drive circuit for a main contactor which opens the contactor when a voltage dip occurs and if the voltage dip is of short duration closes the contactor again but blocks reclosing if the voltage dip persists. The circuit includes means to form an undervoltage pulse which has a duration which is equal to the length of time an undervoltage is present or a predetermined maximum time which ever is shorter. As long as the undervoltage pulse is shorter than the predetermined maximum the contactor is again closed but should the undervoltage persists beyond the predetermined maximum pulse length the drive circuit is allowed to become permanently disabled until further action is taken.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.