| 摘要 |
<p>PURPOSE:To make it possible to detect a large current with high accuracy at a quick response speed, by connecting a DC current transformer for performing AC action to the secondary side of a DC current transformer for detecting a DC current to be measured while outputting a measured current to the output side thereof through a rectifier diode. CONSTITUTION:DC current transformers 18, 21 having primary windings N3 and secondary windings N4 are connected between the connection points of reset resistors 5, 6 and rectifier diodes 7, 10 and an AC power source 4 while rectifier diodes 14-17, reset resistors 12, 13 and a resistor 11 are similarly connected to the sides of secondary windings 20, 23. The DC current transformers 18, 21 perform the action of an AC current transformer. If this current I3 is rectified through the rectifier diodes 14-17 and flowed to the resistor 11, voltage output Eo is obtained at both terminals thereof. Even if the density ratio of a current I1 to be measured and the detection current I3 is high in this time, the winding constitution of the current transformers becomes easy by properly selecting the numbers of the windings N2-N4 of each DC current transformer and leak inductance can be made small. As a result, current detection with a quick response speed can be performed with high accuracy.</p> |
