Copyright © Philip M. Parker, INSEAD. Terms of Use.
| Year | Description |
| 1992 | Invention patented by Thomas K. Phelps, Khanh T. Le, and Gilbert I. Jr. Cardwell on March 2nd, 1992. Abstract: An unregulated D.C. input voltage (V.sub.IN) is processed by a high power chopper (34,36) to produce a first chopped signal having the same voltage as the input (V.sub.IN), and by a low power chopper (56,58) to produce a second chopped signal in synchronism with and having a lower voltage than the first chopped signal. The first and second chopped signals are algebraically combined by transformers (52,54) to produce an A.C. output signal which may be converted to D.C. (V.sub.OUT). The second chopped signal may be controlled to have the same polarity relative to the first chopped signal in which case the voltages add to increase the output voltage (V.sub.OUT), or to have the opposite polarity relative to the first chopped signal in which case the voltages subtract to decrease the output voltage (V.sub.OUT). The periods of addition and subtraction are alternated within the period of the first chopped signal. The ratio of addition and subtraction of the second chopped signal may be varied to adjust the ratio of output voltage to input voltage over a wide range. An energy storage inductor (62 ) is provided in the high power chopper path to average the voltage addition and subtraction. The high power chopper operation may be intermittently interrupted to limit input current flow during startup, and switches (102,104) provided to discharge energy stored in the inductor (62) into the transformers (52,54) and thereby contribute to the output voltage (V.sub.OUT). |
| Source: selected by the editor from original sources. | |
Copyright © Philip M. Parker, INSEAD. Terms of Use.
