This sensitive vibration sensor is
exclusively made for shops to
protect against burglary. It will
detect any mechanical or acoustic vibration
in its vicinity when somebody
tries to break the shutter and immediately
switch on a lamp and sound a
warning alarm. A 15-minute time delay
after switch-on allows sufficient
time for the shop owner to close the
shutter.
The front end of the circuit has a
timer built around the popular binary
counter IC CD4060 (IC1) to provide
15-minute time delay for the remaining
circuitry to turn on. Resistors R3
and R4 and capacitor C2 will make
Q9 output high after 15 minutes. Diode
D1 inhibits the clock input (pin
11) to keep the output high till the
power is switched off. Blinking LED1
indicates the oscillation of IC1.
exclusively made for shops to
protect against burglary. It will
detect any mechanical or acoustic vibration
in its vicinity when somebody
tries to break the shutter and immediately
warning alarm. A 15-minute time delay
after switch-on allows sufficient
time for the shop owner to close the
shutter.
The front end of the circuit has a
timer built around the popular binary
counter IC CD4060 (IC1) to provide
15-minute time delay for the remaining
circuitry to turn on. Resistors R3
and R4 and capacitor C2 will make
Q9 output high after 15 minutes. Diode
D1 inhibits the clock input (pin
11) to keep the output high till the
power is switched off. Blinking LED1
indicates the oscillation of IC1.
