| 摘要 |
PURPOSE:To detect a periodic signal in a short time, by generating a switching pulse signal at the zero-crossing point of a periodic signal, and integrating this switching signal and adjusting the delay time of a delay circuit by the output of an integrator. CONSTITUTION:A delay circuit 3 is connected to a signal source 1, where the period is detected, through a polarity detecting circuit 2, and the signal of the signal source 1 is delayed by one period. The zero-crossing timing is detected by a zero-crossing detecting circuit 11 to which the signal of the signal source 1 is branched and connected, and gate pulses of gate pulse generating circuits 12 and 14 are inputted to switch circuits 4 and 6, which are connected to the circuit 3, through an inverting circuit 13. The difference between the delayed signal and the original signal is checked in circuits 4 and 6 to detect the deviation, and this deviation is inputted to an integrating circuit 7 and is integrated. The output is fed back to the circuit 3 to adjust the delay time to one-period components of delay time. Thus, various periodic waveforms are measured with a simple hard constitution. |
