| 摘要 |
<p>PURPOSE:To make a DC large current transformation device to perform a high speed response, and moreover to perform current detection with high precision by a method wherein a DC current transformer and an air-core coil are combined, output thereof are added, and moreover the circuit constant of the device is selected to reduce ripples of the current transformer. CONSTITUTION:Secondary coils 2a, 3a having the same number of turns are wound around ring cores 2, 3 of two pieces respectively, the coils thereof are connected in series as to have reverse polarity, and a primary conductor 4 is made to penetrate the cores 2, 3 to construct a through type DC current transformer 1. Moreover, at an air- core coil 5, a coil conductor is wound cylindrically, the winding end terminal thereof is wound back by one turn to remove the influence of an outside magnetic field, and the prolonged part of the conductor 4 is penetrated the coil 5 thereof. Then an AC auxiliary electric power source 6 is connected to the output sides of the coils 2a, 3a through a rectifying circuit 7, and the output of the circuit 7 and output of the coil 5 are applied to a summing integrated circuit 8 having the prescribed circuit constant. At this case, the circuit 8 is constructed of resistors R0, R1, R2 and a capacitor C0, and moreover an operational amplifier A1, and a summing integrated voltage is outputted from the amplifier A1.</p> |
