Electronic protective circuit
US4428023A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 1, 1982 |
| Grant date | Jan 24, 1984 |
| Priority date | — |
| Expiry date | Nov 1, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/1257
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The rectifiers for generating direct-currents or hybrid or complex currents for inductive loads must be protected against fault currents which can arise due to faulty operating conditions in the load inductance, by providing for a rapid current cutoff. The heretofore known electronic protective circuits are not suitable for this purpose because the excitation circuit connected in parallel with the load only contains one diode which, in the case of complex currents with large control angle and the thus caused negative voltage peaks, conducts the current during the duration of such voltage peaks, so that the deexcitation circuit periodically only acts as a shunt circuit for the load. To avoid this drawback the new and improved protective circuit contains a controlled valve in the deenergization or deexcitation circuit. According to a preferred embodiment of the protective circuit the extinguishing circuit is connected in parallel to the rectifier bridge and the extinguishing and deenergization circuit possess a common current path making it possible to use a common controlled valve for the extinguishing and the deenergization circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.