Seismic Monitors,
Geophones -
Sensors
and Detectors
Deer Repellent #1: seismic sensor
Deer Repellent #2: Here is a simple sensor, which can detect the seismic vibrations caused by a person or large animal walking nearby. A representative application for the sensor is a deer repellent for the vegetable garden. When a deer steps near the sensor a loud buzzer or beeper sounds for a few seconds startling the would-be vegetable thief away.
Low Cost Feedback Circuit Boosts Efficiency: 01/21/99 EDN-Design Ideas / PDF contains multiple circuits.
Optoelectronic Horizontal VBB Seismometer (Figures):
Seismic Detector: The piezoelectric element of a kitchen gas lighter is used in this simple, yet effective seismic detector