| 摘要 |
PURPOSE:To eliminate only the distrubance pulse for the FM stereo demodulation circuit of sample holding system by giving sample holding again through shift of the phase only when no disturbance pulse exists at the sample holding time. CONSTITUTION:Composite signal A is sample-held at 1st sample holding circuits 7 and 8 via pulses B1 and B2 synchronized with the high and low peaks sent from subcarrier generation circuit 2. And output D and E are sample-held again at 2nd sample holding circuits 9 and 10 via pulses C1 and C2 which are slower than pulses B1 and B2. At the same time, distrubance pulse detection circuit 13 triggers monostable circuit 15 via gate 14 which opens by pulse B1 or B2, and blocks pulses C1 and C2 via gates 11 and 12 only when the disturbance pulse is generated at the sampling time. As a result, only the disturbance pulse can be eliminated from output F and G. |
