Switching power supply
US5661394A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1995 |
| Grant date | Aug 26, 1997 |
| Priority date | — |
| Expiry date | Jun 20, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P80/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a switching power supply a stable dc output voltage having a higher power factor is obtained even for an unstable ac input voltage using a sufficiently broadened duty ratio of the switching signal. The switching power supply include a rectifying circuit 10 for full-wave rectifying an ac input voltage to output a pulsating current, a chopper circuit having a switching device Q1 driven at a sufficiently higher frequency than that of the ac input voltage, an inductor L1 connected in series with the switching device Q1 between output terminals of the rectifying circuit 10, and a capacitor C1 for smoothing a current fed through the inductor L1 to supply a stabilized dc output voltage, an error amplifier 11 and a multiplier 12 for providing a threshold level signal having a full-wave rectified waveform, in which the phase thereof is the same as that of the ac input voltage, and an amplitude corresponding to an error voltage included in an output voltage of the chopper circuit, a comparator 13 for comparing the current of the switching device Q1 with the threshold level signal, and a monostable multivibrator 20 for driving the switching device Q1 according to the output signal of the c…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.