Static charges in objects Dan be detected by this sensitive electroscope. The meter indicates when the object is charged and by the direction of the movement the needle when can say IF the charge is negative or positive. Equivalents of the transistor such as the BF245 can be used. The correct operation point is adjusted by P1. Sensor is a loop of rigid wire. The circuit can be powered from 6 to 9 V supplies. Cells or batteries can be used.
Electroscope
