| 摘要 |
PURPOSE:To remove the damage of tape and to prolong the life, by decreasing the amount of heat dissipation due to eddy current loss, by supplying the pulse in which the conduction angle is less than a specified value, to the magnetic erase head producing the magnetic field of which polarity is mutually inverted. CONSTITUTION:The rectangular waveform voltage obtianed by switching 12 the DC power supply 11 is smoothed at LPF13 and the constant voltage can be obtained at the output side of LPF13 by controlling the timing of the switching at the control circuit 14. Further, the constant voltage output is fed to the power oscillator 15, and the rectangular wave output is fed to the primary winding of the transformer 16. Further, the output of the secondary side is fed to the differentiation circuit 17 to produce the pulse current of which conduction angle is less than 50% and it is fed to the earse head H. As a result, the heat dissipation of the head H due to eddy current loss can be reduced. |
