摘要 |
The performance of AC to DC and DC to DC boost preregulators, and the performance of the equipment of which they form a part, can be improved by means of an adaptive boost switching preregulator which can, when used with a load capable of operating over a range of load voltages, increase or optimize the conversion efficiency and reliability of both the preregulator and the load by adaptively controlling the load voltage as a function of the voltage of the input source. Also, a gain-variable current controller can be provided which allows for accurately controlling the waveform and magnitude of the input current of a switching preregulator as the preregulator load (and hence the input current) varies over a wide dynamic range, yet does so by comparing signals whose magnitudes are essentially independent of the magnitude of the load. In this way, second order effects, which cause degradation in control of power factor in other preregulators as load is decreased, are rendered less significant.
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