Zero-cross detection circuit
US6664817B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 2002 |
| Grant date | Dec 16, 2003 |
| Priority date | — |
| Expiry date | Dec 20, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/083
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a power supply device including a full-wave rectifying and smoothing circuit powered from a commercial AC power supply via two power supply lines, a switching regulator for separating and stepping down the output from the full-wave rectifying and smoothing circuit to output a desired DC voltage, and two capacitors after the full-wave rectifying and smoothing circuit for the terminal noise suppression purpose, a zero-cross detection circuit includes a transistor of which the emitter is connected to the low-voltage output terminal of the full-wave rectifying and smoothing circuit for outputting a zero-cross detection signal from the collector; a first resistor is connected between the base and emitter of the transistor; a second resistor is connected between one of the power supply lines and the base of the transistor; and a third resistor is connected between the other power supply line and the emitter of the transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.