| 摘要 |
PURPOSE:To discriminate the magnitude of a current in different display mode easily and securely, by rectifying an AC current detected by a magnetically coupling detection coil and by making a stepwise display according to comparisons with different discrimination levels. CONSTITUTION:An AC voltage from a conductor 3 connected to an AC power source at one terminal and to a load 5, etc., at the other is rectified through diodes 7 and 8, a capacitor 9, a Zener diode 10, etc. This DC voltage is divided via series voltage-dividing resistances R1-R5 into different-level reference voltages, which are applied to comparing circuits COM1-COM4. Those circuits COM1-COM4, on the other hand, are applied with a DC voltage which corresponds to an AC current detected by a magnetically coupling detector 11, rectifies by a rectifying circit 14, and flowing through the other conductor 4. Then, corresponding LEDs L1-L5 turn on sequentially and successively corresponding to the magnitude of the AC current in the order of the LEDL1, LEDs L1 and L2-, thereby displaying the magnitude of the AC current stepwise in different display mode. Therefore, the agnitude of the current is discriminated easily and securely to prevent an overcurrent from flowing. |
