Electrostatic pickup

An electrostatic pickup converts mechanical motion to an electrical signal by means of varying electrical capacitance. This type of pickup, in which the moving plate is a vibrating metal reed, is used in some types of electronic pianos and organs as an inexpensive method of generating tones. An electrostatic pickup converts mechanical motion to an electrical signal by means of varying electrical capacitance. This type of pickup, in which the moving plate is a vibrating metal reed, is used in some types of electronic pianos and organs as an inexpensive method of generating tones. The electrostatic pickup consists of a capacitor with one stationary plate and one moving plate. The moving plate is typically a steel or brass reed, anchored at one end and free to vibrate at the other end. Another fixed plate is suspended near the vibrating reed, but is electrically insulated.A high voltage is applied between the stationary and moving plates to produce an electric field. The motion of the moving plate induces a varying current through the capacitor formed by the reed and the fixed plate.