Super Sensitive Vibration Sensor

Contents hide

This project is of a super-sensitive vibration sensor (improved version). The purpose of this circuit is the same as a normal vibration sensor, to sense vibrations and activate the circuit and operate or control any AC/DC equipment connected with the relay switch at the output of this circuit. This improvised version is more sensitive than the previous one and also a power saver. There were some minor errors like the heating of transistors which is taken care of in this circuit.

Hardware Components

The following components are required to make a Sensitive Vibration Sensor Circuit

S.no	Component	Value	Qty
1.	Input Supply DC	9-12V	1
2.	PZT Sensor	–	1
3.	Transistor	2N4401, 2N3906	3, 1
4.	IC	NE555 Timer	1
5.	Resistor	1MΩ, 10KΩ, 1KΩ, 22KΩ, 470Ω	3, 2, 3, 1, 1
6.	Electrolytic Capacitor	220µF/25V	1
7.	Relay	–	1
8.	Diode	1N4148	1
9.	LED	–	1
10.	Variable Resistor	1M
11.	Ceramic Capacitor	0.1µF	1

NE555 IC Pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of 555 Timer

2N4401 Pinout

For a detailed description of pinout, dimension features, and specifications download the datasheet of 2N4401

Sensitive Vibration Sensor Circuit

Working Explanation

The operating voltage of this circuit is 9 t0 12 volts. When there is any vibration on the surface where this circuit is located the piezoelectric sensor or PZT will detect it and convert them into an electrical signal that goes into the circuit. The transistors will be activated one by one and the third transistor will send a signal to the IC in this circuit. Now the IC will send a high signal from its output pin and the relay and the LED will be switched on. The consequent current of this circuit is 1.2mA at 12V DC. This circuit can be operated at lower voltages like 3, 5, or 6 volts and for these voltages, you have to replace the 555 timer IC with TLC555 which is a low voltage version of it. The sensitivity of the sensor is adjusted by the 1M variable resistor.