Overview
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A magnetic head has a recording head that writes data to a round magnetic
disk, and a playing head that reads data. For the recording write head,
the magnetic flux density distribution around the head and the response
of the head field to input electric signals are the important characteristics
for its performance evaluation. To study these characteristics, the analysis
must include the effects of eddy currents generated on a yoke.
This example presents the use of magnetic field analysis of the recording
write head with the effects of eddy currents on the yoke, to evaluate the
response characteristic of the head field. |
Eddy Current Density Distribution / Magnetic Flux Density Distribution
| Fig. 1 shows the eddy current distribution around the head, and Fig. 2
shows the magnetic flux density distribution. As shown in the eddy current
density distribution, eddy currents are generated on the surface of the
yoke. This eddy current interrupts the flow of the magnetic flux, resulting
in reduced responsiveness of the head field to the magnetomotive force. |
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Response Characteristic of the Head Field
| Fig. 3 shows the response characteristic of the head field. The head field
waveform is behind the magnetomotive force waveform. This is caused not
by the coil inductance but the eddy currents on the yoke. When analyzing
the response of the write head, the analysis must include the effects of
eddy currents. |
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Reference:
K. Fujiwara, F. Ikeda, A. Kameari, Y. Kanai, K. Nakamura, N. Takahashi,
K. Tani, and T.
Yamada, "Thin Film Write Head Field Analysis Using a Benchmark Problem,"
IEEE Trans.
Magn., vol.36, no.4, pp.1784-1787, July 2000. |
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