Electronic circuit protection device with I2t or other function
US7619865B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 29, 2005 |
| Grant date | Nov 17, 2009 |
| Priority date | — |
| Expiry date | Dec 15, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2017/0806
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit protective device includes a current sensing circuit adapted to be coupled to an output power switch to provide a feedback signal representative of the output current, an overcurrent sensor responsive to the feedback signal exceeding a presettable reference level to provide an overcurrent alert signal, a function generator responsive to the feedback signal to generate a first signal related to the output current according to a preset functional relationship, an integration circuit coupled to the output of the function generator to provide a second signal representative of the product of the first signal and t, where t is the elapsed time following generation of an overcurrent alert signal, and a control circuit responsive to a presettable value of the second signal to disable a gating circuit for the power switch, the shut-down signal being provided at a time which depends on the magnitude of the overcurrent signal. The control circuit also shuts down the gating circuit if the output current exceeds a second preset limit representing a short circuit condition with substantially no delay. A related method, and a function generator in the form of a piece-wise linear approxi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.