I am designing a sound controlled alarm circuit.
The requirement: when you loudly clap your hands within 5 meters of the device, the device is to emit a 1kHz tone for 30s.
the circuit:
The problem is
When I clapped my hands, the speaker could not work. The 555 monostable circuit cannot be triggered. The signal at pin 2 of U5 is shown below:
but if I blown air to the mic, the device worked. The signal at pin 2 of U5 is shown below:
What should be modified to make it work? Thank you.
The requirement: when you loudly clap your hands within 5 meters of the device, the device is to emit a 1kHz tone for 30s.
the circuit:
The problem is
When I clapped my hands, the speaker could not work. The 555 monostable circuit cannot be triggered. The signal at pin 2 of U5 is shown below:
but if I blown air to the mic, the device worked. The signal at pin 2 of U5 is shown below:
What should be modified to make it work? Thank you.
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