Soild state protection circuit for electrical apparatus
US6356423B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 2000 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | Apr 26, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H1/043
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Electrical equipment is safeguarded from damage due to faults by a circuit that provides several levels of protection. A semiconductor switch and a current sensor are placed in series with the electrical equipment. When the current to the equipment exceeds a first threshold for a predefined period of time, the semiconductor switch is rendered non-conductive until the circuit is specifically reset. When the current to the equipment exceeds a greater second threshold, a pulsed signal alternately places the semiconductor switch in conductive and non-conductive states so that the average current applied to the equipment is within an acceptable level. Should the current exceed an even greater third threshold, the semiconductor switch is immediately rendered non-conductive until the circuit is manually reset.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.