| 摘要 |
PURPOSE:To smooth the frequency characteristic near the resonance point of a magnetic head without using a damping resistance by operating a magnetic recording amplifier so that it has a constant current characteristic in a low frequency area of a recording signal and has a constant voltage characteristic in a high frequency area. CONSTITUTION:A voltage feedback circuit F surrounded with a long and short dash alternating line feeds back the voltage in the output side (point A) to the input side (point B) by a resistance R1 and a capacitor C1. The recording signal inputted from a terminal T1 at the recording time is supplied to a magnetic head 4 with the constant current characteristic by a recording amplifier 10. A voltage eR of an output terminal rises in the low frequency area of the recording signal in accordance with a formula eR=iR.omegaL where iR is the recording current and Z(omega) is the impedance of the magnetic head 4, and this voltage is fed back as a feedback voltage to the input side. Consequently, omegaL is very small and the feedback quantity is very small in the low frequency area, but the impedance Z(omega) rises quickly by resonance of the magnetic head 4 near the resonance point of the magnetic head 4 and the voltage eR rises quickly and the feedback quantity is increased there.
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