Let's begin with monarchy. Monarchy was the most common form of government until the 19th century. Monarchy is a form of government in which a single family rules from generation to generation. The power, or sovereignty, is personified in a single individual.
Uses of this type of sensor in the automotive industry include piezoelectric accelerometers, piezoelectric force sensors, and piezoelectric pressure sensors. FIGURE. Piezoelectric sensor circuit. The sensor is a voltage generator and has a resistor connected in series with it.
A proximity sensor can be made on different input to output response principle. Capacitive sensor, Infra red sensor, Ultrasonic sensor, hall sensor, etc can be used to design proximity sensor; now the question is at what cost and how good in static & dynamic characteristics.