| 摘要 |
A variable frequency oscillator for an AC power supply having programmable, multiple phase outputs comprises means including a rate multiplier for generating a clock signal having a selectively controllable frequency and one or more AC signal producing stages responsive thereto. Each AC signal producing stage includes a memory storing a quarter-cycle sinusoidal waveform segment in amplitude sampled form and an address counter responsive to the clock signal for alternately addressing the memory in forward and reverse directions for producing a continuous sequence of half-cycle sinusoidal segments, an output circuit inverting every other one of the half-cycle segments. A first one of the stages produces an output signal having a reference phase angle while the remaining stages are operated such that their associated address counters are offset from the address counter of the first stage by an amount corresponding to an input phase control code, whereby the remaining stages produce output signals having phase angles corresponding displaced from the reference phase angle.
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