| 摘要 |
PURPOSE:To obtain a sinusoidal repetitive voltage generator with less distortion without being affected by an external power supply waveform by obtaining a desired sinusoidal waveform in response to a frequency-division output of a PLL circuit comprising a variable frequency generator, a frequency divider and a phase comparator. CONSTITUTION:A pulse signal fL whose level is inverted every time an AC voltage crosses a ground voltage from a commercial power supply by using a transformer 40, voltage dividing resistors 42, 46 and a voltage comparator 46. Plural frequency- division outputs are obtained from the output signal of a variable frequency generator 50 at a frequency divider 52, the phase of one frequency division output (f) and the signal fL is compared by a phase comparator 48 and a compared output controls an oscillator 50. The output of the frequency divider 52 is fed to a converting means comprising gate circuits 54-60, multiplexer 62, resistors 64-78, and integration devices 80, 82, where the input voltage is converted into a desired waveform in response to the frequency division output. A peak value of the output signal Q of the integration device 80 is detected by a diode 86, compared (78) with a reference voltage. The comparison output is amplified by an inverting amplifier 98 and a non-inverting amplifier 100, and the amplified output is switched alternately by a switch 106 and a repetitive voltage is generated. |
