RMS calculation circuit for digital circuit interrupters
US4658323A · kind A · utility
22Cited by
7References
1Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Jun 10, 1985 |
| Grant date | Apr 14, 1987 |
| Priority date | — |
| Expiry date | Jun 10, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/0935
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The root mean square value of sensed current within a protected circuit is used to determine the occurrence of an overcurrent condition. A frequency multiplying circuit produces a pulse stream having a frequency proportional to the square of the amplitude of an analog signal representation of the circuit current. A root mean square value over a prescribed interval is developed from the squared current value. The RMS value is processed within an integrated circuit trip unit to determine an overcurrent condition and to operate a pair of separable contacts to interrupt the circuit current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.