| 摘要 |
PURPOSE:To eliminate replacement of a voltage converter by dividing the output of an A/D converter by the set number of windings of a number-of-windings setter for setting the number of windings of a bus of a main circuit wound in a current transformer, and then reading the result as detection data. CONSTITUTION:When the number of windings of a bus 11 of a main circuit 10 wound in a current transformer 14 is increased to detect a small load current, the number of windings is input to a number-of-windings setter 20 to apply the set number of windings as a digital value to a controller 22. The controller 22 divides the output value of an A/D converter 19 by the set number of windings, and the result is obtained as load current detection signal. Thus, it is not necessary to replace a voltage converter 18 in response to the number of windings, it can be simply coped with and it is also not necessary to provide many types of expensive voltage converters 18 in which high accuracy is required. |
