| 摘要 |
PURPOSE:To realize a low voltage power source of a recording amplifier by constituting the recording amplifier so as to obtain two outputs of a positive phase and an opposite phase against an input signal, and impressing its amplified output to both ends of a load. CONSTITUTION:A recording FM signal which has been brought to a signal processing by a luminance signal processing circuit and a chrominance signal processing circuit, and a low frequency conversion chrominance signal are inputted to a differential mixer 1. In the differential mixer 1, these two inputs are mixed, and also two mixed signals of a positive phase and an opposite phase are outputted by a differential operation. Subsequently, said two mixed signals are inputted to a differential amplifier 5, and brought to a voltage amplification up to a necessary level in a state of the same characteristic by this circuit. Next, two outputs of the differential amplifier 5 are brought to a current amplification by a current amplifier 3, respectively, impressed to both ends of a load 4, and a recording current signal is made to flow to the load. In this case, a voltage V02 and a -V02 are impressed to one end of the load 4 and the other end of the load 4, respectively, and as a result, the potential difference 2V02 of both of them is impressed to the load 4. Accordingly, as for these amplifiers, it will suffice that 1/2 of the load impressed voltage is obtained, and they can be driven by a low voltage.
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