METHOD AND APPARATUS FOR INDICATING AN ALTERNATING VOLTAGE

摘要

The invention pertains to an alternating voltage indicator placed next to an electrical conductor. Indication is based on the detection of an electric field around a live conductor. Energy is taken capacitively (100) from an alternating electric field in order to bring a resonant circuit (200) tuned to the frequency of the alternating voltage into oscillating state. The voltage of the resonant circuit (200) is amplified (300) and converted into an on/off type (400) signal indicating the presence of an alternating voltage. The indicator according to the invention is electrically safe and it indicates the presence of an alternating voltage regardless of whether the alternating voltage source is loaded at that particular point or not.