| 摘要 |
PURPOSE:To cause an apparatus to follow even a large frequency variation by inputting a result obtained through multiplying a phase difference detected from first and second AC signals by a signal corresponding to the frequency of one of said first or second AC signal, to a voltage controlled oscillator means. CONSTITUTION:The output of an AC motor 1 is made to pass through a voltage transformer 2 to obtain the frequency F1 of a first AC signal. On the other hand, the frequency F2 of a second AC signal generated by an inverter VCO6 is obtained and inputted into a phase comparator 4 to obtain a phase difference between said frequencies F1 and F2. The frequency F1 is F/V converted 11, multiplied 12 by the output of said phase comparator 4, smoothed by a filter 5, and inputted to VCO6 to output said output frequency F2, and returns to the phase comparator 4 to form a PLL circuit. Thus, it is easily performed to synchronize two AC signals differing largely from each other in frequency. |
