REPRODUCING CIRCUIT OF CONTROL SIGNAL

摘要

PURPOSE:To obtain a reproducing circuit of control signals which contains an inverting circuit with a large dynamic range and with no distortion of signal, by obtaining an adverse phase output from the output of an amplifier via a current mirror circuit. CONSTITUTION:A current mirror circuit is provided with transistors TR14 and TR17 plus resistances 15 and 16. The collector current of the TR14 is decided by the difference between the base-emitter voltage VBE of the TR14 and the voltage VD of the output D of an amplifier 1. This current value is transmitted to the collector current of the TR17 with a current transmitting ratio which is decided by the resistances 15 and 16. Here a signal E having the phase adverse to the output D of the amplifier 1 is obtained at a joint of collectors of the resistances 16 and 17. The signal E is converted into a signal E' having the same phase as the signal E via a TR18 which forms a level shifting circuit. Either the signal E' or the output D is extracted to a switch circuit 12 in response to the forward or backward reproduction mode.