35 mm Piezoelectric Sensor without Wire

The 35 mm Piezoelectric Sensor without Wire is a thin circular sensing element used to detect vibration, pressure, force, impact, sound, and mechanical movement by converting mechanical energy into electrical energy. It operates on the piezoelectric effect, where certain materials generate an electrical voltage when subjected to mechanical stress. This sensor is widely used in electronic circuits, robotics, musical instruments, security systems, medical devices, industrial monitoring, and educational electronics projects.

The sensor consists of a 35 mm diameter brass metal disc bonded with a thin layer of piezoelectric ceramic material, usually lead zirconate titanate (PZT). The brass disc acts as a mechanical support and one electrical electrode, while the ceramic layer forms the second electrode. Since this version is supplied without wires, external wires must be soldered to the metal disc and the ceramic electrode before it can be connected to an electronic circuit.

The working principle of the 35 mm piezoelectric sensor is based on the piezoelectric effect. When the sensor is bent, pressed, struck, or exposed to vibration, the ceramic material experiences mechanical stress. This stress causes the internal crystal structure of the piezoelectric material to generate a small electrical voltage across its electrodes. The generated voltage is proportional to the amount of force or vibration applied. When the mechanical force is removed, the output voltage returns to zero.

The sensor can function as both a sensor and an actuator. As a sensor, it detects vibration, pressure, impact, knock, or sound and converts these into electrical signals. As an actuator, when an alternating electrical signal is applied, it vibrates and produces sound, making it useful in piezo buzzers and audio devices.

The sensor is commonly connected to microcontrollers such as Arduino, ESP32, Raspberry Pi, PIC, STM32, and AVR using signal conditioning circuits or analog input pins. Because the sensor can generate relatively high voltage pulses when subjected to strong impacts, current-limiting and protection components are often used to safeguard sensitive electronic circuits.

The applications of the 35 mm Piezoelectric Sensor include knock detection systems, vibration monitoring, impact detection, touch-sensitive switches, electronic drum pads, piezo buzzers, sound detection circuits, machine condition monitoring, burglar alarm systems, structural health monitoring, medical equipment, industrial automation, robotics, educational electronics, musical instruments, and energy harvesting experiments.

The advantages of the 35 mm piezoelectric sensor include high sensitivity, fast response time, compact size, lightweight construction, low power consumption, long operating life, wide frequency response, simple design, and low cost. It requires no external power source to generate an output signal when used as a sensor, making it highly efficient for sensing applications.

In conclusion, the 35 mm Piezoelectric Sensor without Wire is a versatile electromechanical sensing element that converts mechanical stress into electrical signals. Its ability to detect vibration, pressure, force, and impact with high sensitivity makes it an important component in robotics, industrial monitoring, automation systems, musical instruments, medical devices, and educational electronics projects.