Current sensing circuit
US4268884A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 1979 |
| Grant date | May 19, 1981 |
| Priority date | — |
| Expiry date | May 7, 1999 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/085
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A current sensing circuit that controls a contactor that connects a load to power lines. The circuit provides an initial momentary delay period after energization of the circuit and before operation of the contactor to permit transients and other short duration anomalies to die out. An immediately succeeding second momentary delay period during which the contactor operation cannot be changed, assures that an initial inrush of current to the load will not cause a fault signal to erroneously operate the contactor. When a fault signal does cause the contactor to be operated, the circuit cannot be set back to its intended operation condition until energization of the sensing circuit is manually interrupted and reestablished. During normal operation of the circuit when current on the power lines is within acceptable limits, the circuit is latched in its proper operating mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.