| 摘要 |
PURPOSE:To perform automatic maneuvering control precisely and correctly even if the voltage of a conductive body is varied by controlling the gain of a servo amplifier from the conductive body on the basis of sum voltage of voltages induced by right and left pickup coils. CONSTITUTION:Induced voltages VR, VL are generated in the right and left pickup coils 7, 7' by high-frequency current flowing into a conductive wire 1. The voltages VR, VL are amplified by respective amplifiers 8, 8', the amplified voltages are rectified and converted into DC voltages by AC/DC converters 9, 9' and the DC voltages are inputted to the servo amplifier 11 and an adder 12. The amplifier 11 outputs a control signal proportional to the difference of both the input voltages to a driving circuit 10 for a maneuvering motor 5 to allow the motor 5 to perform automatic maneuvering control turning a horizontal displacement variable to zero. Since a differential amplifier 13 controls the gain of the amplifier 11 on the basis of a differential voltage between the sum voltage from the adder 12 and a reference voltage Vo, the automatic maneuvering control can be performed precisely and correctly independently of the voltage variation of the conductive wire 1. |
