Earthquake Detector

BUILD AN

EARTHQUAKE DETECTOR

If you live in an earthquake zone, this vibration sensor can save your property or your life.

If

not, it can be used as a bur-

or many of us that live in a seismically active region, an earthquake is a very real and constant threat. Even moderate earthquakes that are not strong enough to hurt anyone can cause a significant amount of damage to the contents of your house if you are not prepared. Although earthquake prediction has made great strides over the years, it is still very much an art form rather than a science. Earthquakes can strike without warning, and when they do, you do not have time to lock the kitchen cabinets or turn on any emergency lighting, much less find suitable shelter. If those steps can be done automatically at the first sign of an earthquake, property destruction and personal injury can be avoided or minimized. The Earthquake Detector de-

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glar alarm, intrusion detector, o r a game of skill.
ROBERT BULLOCK scribed here is the heart of such an automatic system. The author uses this device to automatically latch all of the kitchen cabinets when an earthquake strikes. The circuit can also be used as a burglar or impact alarm when mounted in a car. When mounted to a garbage can, It can sound a loud alarm if an animal tries to get into the container, A self-contained alarm unit can also be used as a simple game to see how far and how fast someone can carry the device before it triggers. How It Works. A seismograph, which most people are aware of, is a device that measures and records the amount of seismic activity on a strip or drum of paper using vibrating pens, The sensors for that device usually consist of some type of suspended weight with a way to measure how much it moves when the sensor is shaken. The same method is used for the Earthquake Detector. A weight, in the form of a screw, is suspended on the end of a spring. The head of the screw passes through the center of a metal ring. When