![Earthquake Alarm Using Recycled Materials [Project]](/opendir/images/thumbs/od_2088_1_1383400223.jpg)
Based on a 555 timer, a small DC 12 V relay and sounder from a faulty car alarm here is a functional seismic activity detector. It was hooked up to the UPS 12 V battery. The alarm is triggered by an earthquake and sounds for 5 minutes and then goes back to standby. Trigger mechanism is a pendulum that weighs 500 grams from a 2 meter line.
![Earthquake Alarm Using Recycled Materials [Project]](/opendir/images/thumbs/od_2088_2_1383400223.jpg) |