Sine wave inverter
US4907145A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 11, 1989 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | May 11, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M7/538
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In the sine wave inverter disclosed herein the input of a low pass filter is switched at high frequency between positive and negative supply voltages. The switching is controlled by a comparator which is responsive to a composite of signals which include contributions from a sine wave control signal at the same frequency desired for the output and a square wave control signal which is at a frequency substantially higher than the desired output frequency. The filter input voltage is attenuated and phase adjusted to generate a feedback signal having a high frequency component which is substantially in phase with the high frequency control signal. This feedback signal is combined with the sine wave and high frequency square wave control signals to generate the composite of signals which controls the comparator. Accordingly, the duty cycle of the filter input voltage is varied in correspondence with both the sine wave control signal and the loading of the inverter output.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.