1. A method for measuring noise of a magnetic head, comprising:
obtaining a plurality of first parameters by a method comprising:
setting a plurality of first threshold values;
applying first bias current or voltage to a read element of the magnetic head;
applying an external constant transverse magnetic field to the magnetic head;
amplifying first output signal from the read element to produce a first amplified signal;
filtering the first amplified signal to produce a first filtered signal;
generating a first enable signal for each first threshold value in a predetermined first time window by a counting control means with first input signals which include the first filtered signal and the first threshold value;
measuring the first cumulative time duration of each first enable signal;
making a first amplitude-duration distribution according to the first cumulative time durations and the first threshold values; and
calculating the first parameters according to the first amplitude-duration distribution;
obtaining a plurality of second parameters by a method comprising:
setting a plurality of second threshold values;
applying second bias current or voltage to the read element of the magnetic head;
applying an external time-changing transverse magnetic field to the magnetic head;
amplifying second output signal from the read element to produce a second amplified signal;
filtering the second amplified signal to produce a second filtered signal;
generating a second enable signal for each second threshold value in a predetermined second time window by the counting control means with second input signals which include the second filtered signal and the second threshold value;
measuring the second cumulative time duration of each second enable signal;
making a second amplitude-duration distribution according to the second cumulative time durations and the second threshold values; and
calculating the second parameters according to the second amplitude-duration distribution; and
analyzing the relationship between the first parameters and the second parameters with a plurality of predetermined criteria to determine the defects of the magnetic head.
2. The method as claimed in claim 1, wherein the field intensity of the external constant transverse magnetic field is zero.
3. The method as claimed in claim 1, wherein the external time-changing transverse magnetic field varies in periodic waveform.
4. The method as claimed in claim 3, wherein the external time-changing transverse magnetic field varies in single cycle or multiple cycles.
5. The method as claimed in claim 1, wherein the counting control means compares the first threshold value with the amplitude of the first filtered signal or the amplitude of the envelope of the first filtered signal to generate the first enable signal and compares the second threshold value with the amplitude of the second filtered signal or the amplitude of the envelope of the second filtered signal to generate the second enable signal.
6. The method as claimed in claim 1, wherein the counting control means is analog means or digital means.
7. The method as claimed in claim 1, wherein measuring the first cumulative time duration of each first enable signal is implemented by counting the cycles of a clock signal.
8. The method as claimed in claim 1, wherein measuring the second cumulative time duration of each second enable signal is implemented by counting the cycles of a clock signal.
9. The method as claimed in claim 1, wherein the first parameters comprise a plurality of characteristic values of the total population or a part of the total population of the first amplitude-duration distribution.
10. The method as claimed in claim 1, wherein the second parameters comprise a plurality of characteristic values of the total population or a part of the total population of the second amplitude-duration distribution.
11. The method as claimed in claim 9, wherein the characteristic values at least comprise the peak amplitude, the normalized energy, the average amplitude, the RMS and the SNR.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A locking member for locking a card with respect to a shelf having an end with a groove upon completing a card loading process into the shelf, the locking member comprising:
a connecting section joined to the card;
a resilient section extending from the connecting section and having a resilience; and
an engagement section formed at an end of the resilient section and having a shape configured to engage into the groove.
2. The locking member of claim 1, further comprising:
an extension section extending from the engagement section, wherein a position of the engagement section is lowered due to a shrinkage of the resilient section when the extension section is pressed.
3. The locking member of claim 2, wherein the connecting section, the resilient section, the engagement section and the extension section are integrally formed with one another.
4. The locking member of claim 1, wherein the resilient section has a U-shaped configuration.