Overcurrent protection system
US4363064A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 1981 |
| Grant date | Dec 7, 1982 |
| Priority date | — |
| Expiry date | Jul 27, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/093
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An overcurrent protection system adaptable for use with power controllers the single or multi-phase ac, or dc types includes a load current sensing element in combination with an overcurrent sensing/inverse time delay circuit, a power switch and a crowbar circuit. The system also includes a drive circuit, a drive circuit input current sensor, a trip signal detector and a logic circuit. The overcurrent protection system, according to the present invention, uses the drive circuit to power the overcurrent sensing/inverse time delay circuit, to drive the power switch, and to provide a coupling path for an overcurrent fault signal across electrical isolation interface(s) thereof to the logic circuit. Thus, the need for a separate isolated power supply for powering the overcurrent sensing/inverse time delay circuit and the need for separate optical and/or electromagnetic isolation interfaces for coupling of the overcurrent fault signal are eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.