Circuit interrupter with digital trip unit and means to enter trip settings
US4351012A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 15, 1980 |
| Grant date | Sep 21, 1982 |
| Priority date | — |
| Expiry date | Apr 15, 2000 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01H2071/006
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit breaker includes a digital electronic trip unit having a microprocessor. The front panel of the trip unit includes a potentiometer connected across a reference voltage, and a numeric display device. The potentiometer is adjusted by an operator to enter a value of a parameter defining the time-current characteristic of the circuit breaker. An analog-to-digital converter receives the voltage supplied by the potentiometer and converts it to a digital quantity for use by the microcomputer in performing limit checks with the current flow through the contacts of the breaker. The microcomputer formats the converted digital value of the potentiometer voltage and supplies it to a front panel-visible numeric display so that the value of the potentiometer setting as interpreted by the microcomputer in defining the time-current trip characteristic is presented on the numeric display to provide real-time feedback to the operator as he adjusts the parameter value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.