Switching ac voltage regulator
US4791348A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 6, 1988 |
| Grant date | Dec 13, 1988 |
| Priority date | — |
| Expiry date | Jan 6, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M5/293
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A pulse-width ac voltage regulator that provides a precisely ac output voltage without the need for any inefficient protective circuitry for ensuring proper operation when it repeatedly switches between its two alternative operating modes. A transformer is arranged with a first winding connected between an input terminal and an output terminal and a second winding connected between one end of the first winding and a control terminal. A special switch assembly including four separate circuits, each having a series connected transistor and diode, is controllably switched such that the second winding is alternatively shorted or excited, to provide a stepped-up (or stepped-down) voltage out of the first winding. The transistors are controllably switched at a frequency substantially greater than that of the ac input signal and at a duty cycle selected to provide the desired ac output voltage. Each time a transistor in the assembly is biased ON or OFF, electrical current is immediately diverted from one transistor to another, without the need for any inefficient snubber circuit or the like.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.