JPH0480664A - Lead signal pulse height mean value measuring circuit - Google Patents

Abstract

PURPOSE:To enable accurate measurement by dividing an integrated value of maximum peak values of a lead signal from the moment of inversion in polarity of the lead signal from negative to positive to the moment of inversion from positive to negative by a frequency of inversion from positive to negative. CONSTITUTION:A zero-point detector 2 outputs a pulse signal 102 the moment the polarity of a lead signal 101 to change an amplitude and a polarity in proportion to time inverts from negative to positive and a pulse signal 103 at the moment of inversion from positive to negative. A peak holding circuit 1 holds maximum peak values of the signal 101 to obtain a signal 104. An analog switch 3 outputs to an integrator 4 a signal 105 which allowed the signal 104 to conduct between the outputting of the signal 103 and that of the subsequent signal 102. The integrator 4 integrates pulse peaks of the signal 105 to be outputted to a divider 6. A counter 5 counts the number of pulses of the signal 103 to be outputted to the divider 6. The divider 6 divides an integrated value of maximum peak values of the signal 101 by the number of pulses of the signal 103 and thus, a lead signal pulse height mean value is obtained to be outputted to a signal line 12.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a read signal wave height average value measuring circuit.

[Prior Art] Conventionally, a read signal wave height average value measuring circuit for a magnetic disk or the like generally includes an envelope forming circuit for the read signal and a smoothing circuit for smoothing the envelope waveform.

[Problems to be Solved by the Invention] This type of read signal wave height average value measuring circuit forms an envelope of the read signal and obtains the read signal wave height average value by smoothing the envelope waveform. For a read signal which is high and whose peak values fluctuate greatly, there are two drawbacks: it is difficult to obtain an accurate measurement of the average read signal peak value.

An object of the present invention is to eliminate the above-mentioned drawbacks, and calculate the integrated value of the maximum peak value of the read signal during the period from the moment when the polarity of the read signal is reversed from negative to positive to the moment when the polarity is reversed from positive to negative. By dividing by the number of times of reversal from positive to negative, the average value of the read signal wave height is obtained, so even in the read signal where the frequency is high and each wave height value fluctuates greatly, the signal is always accurate. An object of the present invention is to provide a REET signal wave height average value measuring circuit that measures a wave height average value.

[Means for Solving the Problem] The read signal average value measuring circuit according to the present invention detects the first pulse signal at the instant when the polarity of the read signal whose amplitude and polarity change in proportion to time is reversed from negative to positive. output,
At the instant the polarity of the read signal is reversed from positive to negative, the second
a zero point detector that outputs a pulse signal; a peak hold circuit that holds the maximum peak value of the read signal; a second pulse signal of the zero point detector is outputted, and a next first pulse signal is outputted; an analog switch that conducts and outputs the maximum peak value of the read signal; an integrator that integrates and holds the output value of the analog switch; and a first pulse signal and a second pulse signal of the zero point detection circuit. The device includes a counter that counts the total number of pulse signals, and a divider that divides the integrated value of the integrator by the count number of the counter to calculate an average value of the read signal wave height.

[Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a read signal wave height average value measuring circuit according to the present invention.

In FIG. 1, 1 is a peak hold circuit, 2 is a zero point detector, 3 is an analog switch, 4 is an integrator, 5 is a counter, 6 is a divider, and 11 to 13 are signal lines, respectively.

FIG. 2 is a timing diagram showing the operation of FIG. 1. 1st
The operation of this embodiment will be explained with reference to FIGS.

The read signal 101 is a magnetic disk read signal that changes amplitude and polarity in proportion to time. First, a read signal 101 to be measured is transmitted to a peak hold circuit 1 and a zero point detector 2 via a signal line 11. Zero point detector 2
, the first pulse signal 102 is generated at the instant when the polarity of the read signal 101 is reversed from negative to positive, and the second pulse signal 103 is generated at the instant when the polarity of the read signal 101 is reversed from positive to negative. A first pulse signal 102 and a second pulse signal 103 are transmitted to the peak hold circuit 1 , analog switch 3 , and counter 5 through a signal line 13 .

In the peak hold circuit 1, the first pulse signal 1
The operation of holding the maximum peak value Vn of the read signal 101 during the period from the rise of 02 to the rise of the second pulse signal 103 and clearing it to O at the fall of the second pulse signal 103 is repeated to obtain the signal 104. .

In the analog switch 3, the second pulse signal 10
Signal 10 conducts signal 104 at the same time as signal 3 rises.
5 is output to the integrator 4. In the integrator 4, the signal 1
05 are integrated, and outputted to the divider 6 as an integrated value of each maximum peak value of the REET signal 101. The counter 5 counts the number of pulses of the second pulse signal 103 and outputs it to the divider 6. The divider 6 divides the integrated value of each maximum peak value of the read signal 101 by the number of pulses of the second pulse signal 103 to obtain an average read signal peak value, and outputs it to the signal line 12. do.

[Effects of the Invention] As explained above, the present invention calculates the integrated value of the maximum peak value of the read signal during the period from the moment when the polarity of the read signal is reversed from negative to positive to the moment when the polarity of the read signal is reversed from positive to negative. , by configuring to obtain the read signal wave height average value by dividing by the number of inversions of the positive to negative inversion,
This has the effect of making it possible to accurately measure the read signal wave height average value.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a read signal wave height average value measuring circuit according to the present invention, and FIG. 2 is a timing diagram of the circuit in FIG. 1. 1...Peak hold circuit, 2...Zero point detector, 3
...Analog switch, 4...Integrator, 5...Counter, 6...Divider, 11-13...Signal line.

Claims (1)

[Claims] A first pulse signal is output at the instant when the polarity of a read signal whose amplitude and polarity change in proportion to time is reversed from negative to positive, and a second pulse signal is output at the instant when the polarity of the read signal is reversed from positive to negative. a zero point detector that outputs a pulse signal; a peak hold circuit that holds the maximum peak value of the read signal;
an analog switch that is conductive and outputs the maximum peak value of the read signal during a period from when the second pulse signal of the zero point detector is output to when the next first pulse signal is output;
an integrator that integrates and holds the output value of the analog switch; a counter that counts the total number of first pulse signals and second pulse signals of the zero point detection circuit; A read signal wave height average value measuring circuit comprising a divider that calculates a read signal wave height average value by dividing by a count number.