Contact less AC Mains Indicator

Description

AC Mains Indicator-based Circuit can detect AC voltage without any electrical contact among the conductor carrying AC current or voltage. Thus it can be used to detect mains AC voltage without removing the insulation from the conductor. It would detect the presence of AC Voltage simply by placing it near the conductor. In the absence of AC voltage, the display would show any digit (0 through 9) permanently.

If the Mains Supply is available in the conductor, the electric field would be inducted into the sensing probe. Since IC used is CMOS type, its input impedance is extremely high. Thus the induced voltage is sufficient to clock the counter IC. And display count advances rapidly from 0 to 9 and then repeats itself. This is the indication for the presence of mains supply. Display stops advancing when the unit is taken away from the mains carrying conductor.