SENSITIVE VIBRATION DETECTOR

This vibration detector is realised using readily available, lowcost
components. One of its many applications is in a rolling shutter
guard for offices and shops. The detector will sense vibration caused by
activities like drilling and switch on the connected load (bulb, piezobuzzer,
etc) to alert you.
The circuit works off a 6V battery or 6V regulated power supply and
uses a piezoceramic element as the vibration detector. The same is easily
available from electronics/telephone component vendors or you can take it
out from an active buzzer.

Material Need :

• IC - IC CD 4017
• Diode ,Zener Diode, Transistor,SCR
• LED
• Relay
• Resistance ,capacitor 
• Pizo element

Initially, when the power is switched on, decade counter IC1 is reset
by power-on-reset components C2 and R1. As a result, Q0 output (pin 3)
of IC1 goes high and the entire circuit is in
idle state. LED1 indicates the power status.
In the event of  vibrations, IC2 is clocked by the
pulses from the piezoceramic element connected to its
clock pin 14. Q1 through Q9 outputs
of IC2 are fed to relay- driver switching
transistor T1 through diodes D1 through D9 connected in
OR mode.

Immediately after clocking, any of the outputs Q1 through Q9 would go
high and npn transistor T1 would conduct.
As a result, SCR1 is fired through its gate. This, in turn, energises relay
RL1. The relay contacts can be used to switch any alarm device to indicate
vibration detection. The circuit can be reset by momentarily pressing
switch S1.

Zener diodes ZD1 and ZD2 at the clock input of IC1
are used for protection against high
voltage input. In the case of repeated false triggering of
IC1, add a 100nF capacitor in parallel to
the piezoceramic element.
The pin configuration of SCR
BT169 and the back view of the
piezo element are shown in Fig. 2. Fig.
3 shows suggested location of the vibration
detector for rolling shutters of banks, shops, etc





Circuitry of Delay Counter:

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