Residual current detection circuit
US7068047B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 25, 2003 |
| Grant date | Jun 27, 2006 |
| Priority date | — |
| Expiry date | Mar 25, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/332
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A residual current detection circuit comprises a current transformer CT for detecting an imbalance current indicative of a residual current and a full wave restifier FWR for providing an output whose amplitude corresponds to the magnitude of the residual current. The FWR output is applied simultaneously to two channels. The first channel includes a first comparator COMP1 to provide a first signal which persists during periods when the amplitude of the output exceeds a first level. The second channel includes a capacitor C2 which acquires a charge corresponding to the output level and a second comparator COMP2 for providing a second signal in response to the capacitor voltage exceeding a second level. An output is provided from the circuit only when the first signal is coincident with the second signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.