Low voltage startup timer for a microcontroller-based circuit breaker
US8116056B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 14, 2008 |
| Grant date | Feb 14, 2012 |
| Priority date | — |
| Expiry date | Jul 28, 2030 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H3/05
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A circuit breaker capable of microcontroller-based fault detection having a backup circuit for causing the circuit breaker to trip in response to a microcontroller fault, including a timing circuit powered by a power supply and a microcontroller. The timing circuit is electrically coupled to an SCR that causes the circuit breaker to trip. The timing circuit includes a BJT coupled to the gate of the SCR. The microcontroller has a first output coupled to the timing circuit and a second output coupled to the SCR. The first output is coupled to a node between a resistor and a grounded capacitor in the timing circuit, and the node is coupled to a gate of the SCR and to a base of the transistor. A voltage develops at the node sufficient to cause the gate of the SCR to turn on unless the microcontroller pulls the first high-impedance output to a logic low state.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.