| 摘要 |
PURPOSE:To generate an accurate write clock in every time that the sine wave of this ringing traverses 0V, by providing a crystal filter, where a clock run signal extracted from a multiple signal is injected to generate a ringing. CONSTITUTION:The multiple input signal from an input line 21 is inputted to a clock run extracting circuit 23 through a band amplifier 22. The clock run signal is extracted by pulses, which are extracted from the horizontal synchronizing signal by an extracting pulse generating circuit 25, and is applied to a crystal filter 28 of 2.86MHz. The ringing output of the crystal filter 28 has the average value fixed to 0V by a zero bias circuit 29. The ringing waveform fixed to 0V is given to zero cross detector 30, and a pulse I is generated at an intersection between this ringing waveform and the 0V level. This pulse is used as a clock for the write of the multiple signal to a storage device to perform a stable write operation. |
