PURPOSE: To provide a device for indicating even a small load current by causing a capacitor to discharge through an indicator when the voltage across the capacitor exceeds a threshold voltage.

CONSTITUTION: No voltage is applied across a resistor 8 until the voltage across a capacitor 5 reaches the threshold voltage of a constant-voltage diode 9. When the voltage exceeds the threshold voltage of the diode 9, a voltage is applied across the resistor 8, so that a PUT 7 is turned on and the capacitor 5 discharge. As a result, a light emitting diode 6 is turned on. When the capacitor 5 completely discharges, the PUT 7 is turned off and the discharge from the capacitor 5 through the diode 6 is stopped, and then, the diode 6 is turned off. The turning on of the diode 6 and charging of the capacitor are repeated, resulting in the intermittent turning-on of the diode 6 at time intervals (t). Therefore, the magnitude of a load current can be confirmed from the time intervals (t).