Seismometer

A seismometer (earthquake detector) was created using a piezoelectric element. Piezoelectric elements are crystals that generate electricity when exposed to a mechanical frequency; conversely, they may also vibrate at a certain frequency when exposed to an alternating current at a resonant frequency. This project took advantage of the former principle in order to generate a current when the element vibrated. The sensitivity of the element used was adjustable through a 10 KΩ potentiometer. Whenever the piezoelectric element generated electricity, it would turn on a simple NPN transistor via a simple LM741 op-amp. When the transistor was activated it would activate a buzzer through an NE555 timer. The NE555 timer was the element which adjusted the length of time that the buzzer would sound an alarm. The entire system was powered through a 9-volt battery. A PCB was designed to accomidate the resulting circuitry, and was designed using DipTrace.