| 摘要 |
<p>PURPOSE:To enable the detection of current at a high accuracy without being affected by noise voltage from a transmission line by dividing a load resistance of a DC current transformer so as to enter the receiving side separated by the line. CONSTITUTION:The detection signal receiving side 14 of a DC current transformer is made up of detection coils 2 and 3 connected to a DC bus 1 to be tested, an input power source 4, rectifying diodes 5, 6, 7 and 8 and a load resistance 9a. The detection voltage of the load resistance 9a is transmitted to the receiving side 15 through the transmission line 10. At this point, current proportional to DC flowing through a DC bus 1 is shunted to the load resistances 9a and 9b. The terminal voltage thereof, namely, voltage across the load resistance 9b serves as value of the detection voltage, which is inputted into an input impedance 11 of an arithmetic amplifier 13 to be used for control. If the value of the load resistance 9b on the receiving side 15 is smaller than that of the load resistance 9a, the noise resistance on the receiving side can be improved.</p> |
