| 摘要 |
PURPOSE:To eliminate the error pulse caused by the shoulder ring effect, by providing the pulse forming circuit, the negative and positive peak pulse extracting circuit and others to prevent the error pulse from being included into the negative and positive peak pulses. CONSTITUTION:The read-out signals are converted into the positive polarity pulse C, negative polarity pulse -C and delaying pulse G each via pulse forming circuit 10 and others. Then active-high delay zero-cross pulse H is produced through zero-cross pulse generating circuit 12 and in response to the rear edge of pulse G. After this, active-low negative peak pulse I is generated through negative and positive peak pulse extracting circuits 18 and 19 and inresponse to pulses C and H, and then positive peak pulse J is generated in response to pulses -C and H respectively. Pulses I and J produce peak pulse M via OR gate 17 and are then sent to the demodulating circuit. No error pulse is contained in pulses I and J, and thus no error pulse is included in pulse M either. As a result, the error pulse due to the shoulder ring effect can be eliminated. |
