Safe anti-theft alarm circuit

Shown is a safe anti-theft alarm circuit ,
which is mainly composed of voltage sensor BZ1, tilt sensor
B22, temperature sensor RT, voltage comparator IC 3 and other components. The piezoelectric sensor BZ1 is connected to the input end of the voltage comparator IC3-1. When it is vibrated, an electrical signal will be generated. The electrical signal is amplified by IC3-1 and IC3-2 and then passes through the OR gate circuit IC4-1 and IC4- 2 to drive transistor VT1. The conduction of VT1 will cause the relay to operate, and the contacts of the relay will turn on the alarm buzzer.     There is also a tilt sensor (mercury switch) on the safety lock. When someone moves the safe, the mercury switch on the safety lock is turned on, and the @ pin of the OR gate circuit IC4-1 also outputs a high level to alarm.     The third sensor is a temperature sensor. When the safe is subject to high heat, the resistance value of the thermistor RT decreases, and pin 8 of IC3-3 outputs a high level and adds it to the OR gate circuit IC 4-1. Activate the alarm circuit.