| 摘要 |
PURPOSE:To allow generation of a drive current unlimitedly close to a sine wave through a relatively small circuitry, i.e., low resolution digital processing. CONSTITUTION:Second step current generating circuits 5a-7a generate step currents corresponding to the variation widths of step wave signals outputted from first step current generating circuits 5-7. When a triangular signal outputted from a triangular wave generating circuit 9 is amplified by current control amplifiers 9-11, the amplification factors are determined based on the ratios of output currents from the second step current generating circuits 5a-7a. Since the amplitude of triangular signal fits to each level of step wave signals a smoothly varying drive signal can be obtained through low resolution digital processing, i.e., small scale circuitry. |
