Testing circuit.
After assembly is complete, try checking the device again. In particular, pin capacitor. If the wrong polarity, the circuit will not work at all (C1). Including the direction pin ICs. When finished, the power input to the circuit to hear the siren. Alternating high and low tone out of the the speaker.
If not satisfied, it can be changed,By changing the C1, which controls the speed. Fast or slow to change tone. And C2 is capacitor, control the siren tone to a high and low tone. as the need to try to change myself.
If it is used as a burglar alarm. They should find a box for it. The sensor is a switch, turn on-off power to the circuit. Placed sensors are as sensitive as a door or window. Your alarm system will be easy to use it.