Home Security Devices

The IC LS1240A from SGS Thompson is specifically designed for generating a 2 tone ringtone generator circuit. Thus the IC specifically becomes suitable for landline telephones for producing the ringtones when a call is received. However with little modifications the IC can be easily utilized for normal applications, in circuits where a double tone alarm … Read more2 Tone Ringtone Generator Circuit

The article shows an earthquake sensor circuit idea which incorporates an innovative way of detecting the minutest of shocks caused by a possible earthquake tremor. The circuit is so sensitive that it is able to detect tremor of 4 on the Richter scale, yet remains unaffected to loud sounds or irrelevant bangs or noises. Introduction … Read moreEarthquake Sensor Circuit – Seismic Sensor

In this article we are going to learn a few interesting SCR based application circuits and also learn the main features and properties of a thyristor or SCR device What’s an SCR or Thyristor SCR is the acronym of Silicon Controlled Rectifier, as the name suggests it’s a kind of diode or a rectifying agent … Read moreSimple SCR based Application Circuits

The discussed Earth leakage circuit breaker diagrams will silently monitor the electrical condition of your appliances and the Earth connection of your house. Here we will learn 2 designs, first using transistors only and the second using IC LM324. Introduction If anything goes wrong with them it will instantly switch off the mains and stop … Read more2 Simple Earth Leakage Circuit Breaker (ELCB) Explained