| 摘要 |
PURPOSE:To detect the usage impossible state of a head in an early stage by detecting the level of a voltage value which flows in a fixed resistor connected to one end of the main body side of a rotary transformer. CONSTITUTION:In a recording state, (a) and (c) are connected in a switching circuit 3 and a recording signal amplified in a recording amplifier 5 is transmitted from the main body side to a magnetic head 1 installed on a rotary cylinder through the rotary transformer 2 so as to be recorded. At this time, the resistance value of the fixed resistor 7 is about 1OMEGA and the recording signal and current which flow to the main body side of the rotary transformer 2 are converted in terms of the voltage and the voltage value is detected in terms of level by a level detector 6. In a reproducing state, the recorded signal is reproduced in the magnetic head 1 and the reproduced signal is transmitted to the main body side through the rotary transformer 2. The reproduced signal is inputted in a reproducing amplifier 4 through the switching circuit 3 so as to be amplified. Thus, in the case of recording and reproducing wide band signals, one head 1 can detect the usage impossible state of the head in an early stage.
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