The rectifier 1748 converts alternating signals, such as the speech signals 1706 shown in FIG. 17B, which periodically reverse direction, to direct signals that flow in only one direction. In one embodiment, the rectifier 1748 may be made of semiconductor diodes, silicon-controlled rectifiers, or other silicon-based semiconductor switches. In one embodiment, the rectifier 1748 may be implemented as part of a DSP or in software. The rectifier 1748 generates the rectified signals 1750 by rectifying the speech signals 1706. Because of the alternating nature of the input speech signals 1706, the rectifier 1748 may produce DC rectified signals 1750 that, though unidirectional, include pulses. The rectified signals 1750 may be smoothed by an electronic filter, which may be a set of capacitors or chokes, followed by a voltage regulator.
