Variable Capacitor - Transducers

Transducers

Variable capacitance is sometimes used to convert physical phenomena into electrical signals.

• In a capacitor microphone (commonly known as a condenser microphone), the diaphragm acts as one plate of a capacitor, and vibrations produce changes in the distance between the diaphragm and a fixed plate, changing the voltage maintained across the capacitor plates.
• Some types of industrial sensors use a capacitor element to convert physical quantities such as pressure, displacement or relative humidity to an electrical signal for measurement purposes.
• Capacitive sensors can also be used in the place of switches, e.g. in computer keyboards or “touch buttons” for elevators that have no movable parts.