| 摘要 |
PURPOSE:To obtain a synchronizing pulse of high accuracy for burst waveform change by utilizing the fact that a zero-crossing point of a burst signal is a fixed number, and counting a zero-crossing point. CONSTITUTION:An input signal 9 containing a burst signal is added to a clock generator 12, zero-crossing detector 10, and positive/negative peak holder 11. The peak holder 11 supplies threshold voltage to the detector 10. This detector 10 outputs a pulse when the burst signal is at a zero-crossing point. On the other hand, a counter 13 counts an output pulse from the detector 10, but counts only pulses coming at a constant interval, using a clock from the generator 12. When the counter 13 counts fixed numbers in succession, a synchronizing pulse generator 14, which is controlled by a clock from the generator 12, outputs a synchronizing pulse 15. Thus the synchronizing pulse of high accuracy can be obtained for the burst waveform change. |
