Solve a “spikey” problem with this easy-build mains transient detector

Domestic mains outlets provide a nominal 230V a.c. in many parts of the world - or in the USA, a nominal 115V a.c. It is not unusual, however, for sudden “skips” to occur in the mains voltage, measuring up to 1,000V (1kV) and higher. These are called mains transients - also referred to as spikes. When such “skips” last longer than 10 milliseconds, they are referred to as surges.

It need hardly be said that a piece of equipment which has been designed to run off 230V a.c. could be seriously damaged by a 1,000V transient - in fact by far less than this. The point at which damage occurs to various kinds of electrical equipment is hard to quantify. This depends not only on the magnitude of a transient, but on its duration, and on the equipment itself. Having said this, however, the Transient Tracker described here will give a good indication as to when a risk is present, and will enable you, without the aid of expensive or sophisticated equipment, to determine whether such transients exist on your mains supply.