To begin with, IC 555 Timer Based Vibration Alarm Circuit is any easy to make, as it senses vibration and gives sound and light alert.
Security systems, factory machines and anti-theft devices use this circuit and also the main component, the 555 timer IC sends a steady signal when the sensor detects vibration.
Circuit Working:

Parts List:
| Components | Values | Quantity |
|---|---|---|
| Resistors | 10Ω 1/4 watt | 1 |
| 100Ω 1/4 watt | 1 | |
| 1M 1/4 watt | 1 | |
| 1k 1/4 watt | 1 | |
| Capacitors | Ceramic 0.01µF | 1 |
| Electrolytic 100µF 16V | 1 | |
| Semiconductors | IC 555 | 1 |
| Transistor BC547 | 1 | |
| LED Any 5mm 20mA | 1 | |
| Buzzer | 1 | |
| Switch ON/OFF | 1 | |
| Sensor Vibration Sensor 18020P | 1 | |
| Battery 9V | 1 |
This circuit uses IC 555 in monostable mode and vibration sensor connects to pin 2 trigger pin through resistor R3 and capacitor C2 which helps cut noise.
Also, pin 5 connects to ground with capacitor C1 for stability and output pin 3 connects to BC547 transistor base using resistor R2.
Then transistors collector powers buzzer and LED and no vibration with sensor stays inactive with pin 3 stays low and buzzer and LED stays OFF.
After that, when sensor feels vibration, it sends signal to pin 2 and IC gives high output for time set by R3 and C2.
High output turns ON the transistor, buzzer and LED turn ON with alarm sound and light.
Now ON/OFF switch controls battery power and with ON the circuit works and with OFF the power cuts and saves the battery.
Finally, after vibration stops and time ends the pin 3 goes low and buzzer and LED turns OFF.
How to Build:
To build a IC 555 Timer Based Vibration Alarm Circuit follow the below mentioned steps:
- First, gather all parts as shown in the circuit diagram.
- Next, pin 1 of IC 555 connects to GND.
- After that, pin 2 connects between R4, vibration sensor and GND
- Now pin 3 connects to base of Q1 transistor through R2.
- Then pins 4 and 8 connects to +9V supply.
- Also, pin 5 connects to GND through C1.
- Further, pins 6 and 7 connects together through R3 and C2 where C2 anode goes to pin 6 and cathode to GND.
- Now collector of Q1 connects to +9V through buzzer, emitter of Q1 connects to GND and between collector of Q1 and buzzer connects LED1 and R1 in series to +9V.
- Then add ON/OFF switch between +9V battery and the rest of circuit and also, negative of battery goes to GND.
Conclusion:
Overall, this IC 555 Timer Based Vibration Alarm Circuit is small, simple and works well, as it senses vibration, gives sound and light alert.
Furthermore, it is useful for security, factory use or any place needing vibration check, also the circuit needs few parts, easy to make with low cost and is quite reliable.