Tag Archives: electrical projects for students

Can earthquakes be predicted? A simple magnetometer for detecting earthquake precursors

magnetometer: n. [Magneto- + -meter]
An instrument for measuring the intensity of magnetic forces [1913 Webster]

precursor:  One who, or that which, precedes an event, and indicates its
approach; a forerunner [1913 Webster]

Scientists, particularly in Japan, have for many years been gathering evidence of electromagnetic signals that come from under the ground before earthquakes. The bigger the signal, the bigger the quake is likely to be. This can occur hours before, and in some cases, days or even weeks before the quake itself. Why it happens is not well understood but current theory is that it has to do with rocks creating large electric currents as a result of crushing or grinding under high pressure. Several methods have been used to detect these reportedly erratic, electromagnetic pulses. The method described here is one of the simplest. Technically, it’s called a “search coil magnetometer.” This does not respond to very slow magnetic changes, but it can sense short-term ones, making it suitable for detecting earthquake precursors. Continue reading

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Recording Earthquakes for Beginners – The Background Story

Background

In my search for educational projects that can engage a kid’s interest, I recently began looking into seismology (from Ancient Greek, “seismos”, an earthquake and “logia”, study of.)

Being a rather high-tech subject, I was skeptical of my chances of reducing it to something kids could do, but I gave it a shot anyway, since it’s very applicable here in Taiwan, where earthquakes average a couple a day. (You can see them on this website: http://www.cwb.gov.tw/eng/index.htm )

The goal was to come up with some kind of a detector; the simplest and cheapest design possible that a student could plug into a computer and record real earthquakes. Although still in progress I wanted to share what I’ve done so far as it’s a fascinating field and full of good, observable data that will give anyone a deeper understanding of the planet we live on. Continue reading

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Home made battery tester/galvanometer

A galvanometer is a device for measuring the flow of an electric current. (From Galvani, a professor of physiology at Bologna, and meter, measure.)

In this day and age, electricity has found its way into our lives in the most unexpected areas. Nobody could have imagined how useful computers and cellphones would become, but how far can it go? I thought electric toothbrushes were pushing the limit once, but then I saw a computer controlled toilet seat….. Continue reading

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