| 摘要 |
PURPOSE:To give linearity extending over high currents from low ones by providing an ion core with a feedback coil and an amplifier amplifying secondary- coil output currents and exciting the feedback coil by the amplifier while exciting a primary coil so as to reach reversed polarity when the current transformer is manufactured by winding primary and secondary coils onto the iron core. CONSTITUTION:The primary coil 11 and the secondary coil 12 are wound onto the iron core 10, and the feedback coil 13 is further wound. The linear amplifier 14 amplifying an output from the secondary coil 12 is connected to the secondary coil, the feedback coil 13 is excited by a constant-current amplifier 15 driven by an output from the amplifier 14, and magnetic flux is fed back. That is, feedback magnetic flux 18 formed through the secondary coil 12, the amplifiers 14, 15 and the feedback coil 13 is added to magnetic flux 17 formed by a primary coil input 16 to the primary coil 11 in reversed polarity form in the iron core 10. Accordingly, the magnetic flux of the iron core 10 is minimized, and adverse effects by exciting impedance are eliminated. |
