Domestic Seismic Alarm

Posted on Feb 7, 2014

When the switch is on, the seismic alarm isin detection condition. When there is no earthquake, IC1`s pin 3 outputs low level and VT is disconnected. The alarm circuit does not work. When there is an earthquake, the magnet will move vertically. When it is away from IC1, IC1`s pin 3 outputs high level and VT is connected. HL is illuminated. IC2 and

Domestic Seismic Alarm
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IC3 begin to work. When the sound signal output by IC2 is amplified by IC3, BL will make an alarm sound.

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