Simple micro power disconnection burglar alarm circuit

Component selection All components are common parts, and their values ​​are shown in the figure. IC is CW9561 four-sound alarm integrated block. Different alarm signals can be obtained through different wiring methods. Of course, other types can be selected according to needs and conditions. The integrated block .Y is an 8Ω small treble or woofer.
Some notes
1. Because R1 takes a large value and forms an electronic switch together with BG1, it not only has high sensitivity, but also greatly reduces the power consumption of the alarm in the alarm state. This is one of the outstanding features of this circuit. In the measurement and warning state, the power consumption of this circuit is about 5μA, and the three-section fifth battery can be used for more than half a year. After more than four years of use, the effect is good.
2. The warning line can be directly coated with fine lacquer, or ordinary multi-strand soft wire can be used to remove the insulation, and the internal thin copper wire is taken out one by one, and then connected end to end. The length depends on the need. Note that it is good to be in good contact. , but also to remain concealed and fragile.
3. If the alarm sound is small, the circuit can be modified accordingly, such as increasing the power supply voltage to increase the output power.
As shown in the figure, the bias voltage is supplied from the b pole of R1 to BG1 in the circuit. In the alarm state, the b-pole bias voltage is short-circuited to the ground via the warning line S, and BG1 does not work. In case of scam, S is disconnected. BG1 immediately works. BG1 emitter current is triggered by R2 to trigger SCR, the indicator LED is on, and the IC outputs an alarm signal. After BG2 and BG3 compound amplification, the speaker is played. At this time, even if S is turned back on. Also, it is correct to report, only the power switch can be turned off to release the alarm, so it has anti-destructive effect. Component selection All components are common parts, and their values ​​are shown in the figure. IC is CW9561 four-sound alarm integrated block. Different alarm signals can be obtained through different wiring methods. Of course, other types can be selected according to needs and conditions. The integrated block .Y is an 8Ω small treble or woofer.
Some notes
1. Because R1 takes a large value and forms an electronic switch together with BG1, it not only has high sensitivity, but also greatly reduces the power consumption of the alarm in the alarm state. This is one of the outstanding features of this circuit. In the measurement and warning state, the power consumption of this circuit is about 5μA, and the three-section fifth battery can be used for more than half a year. After more than four years of use, the effect is good.
2. The warning line can be directly coated with fine lacquer, or ordinary multi-strand soft wire can be used to remove the insulation, and the internal thin copper wire is taken out one by one, and then connected end to end. The length depends on the need. Note that it is good to be in good contact. , but also to remain concealed and fragile.
3. If the alarm sound is small, the circuit can be modified accordingly, such as increasing the power supply voltage to increase the output power.