NO. DE PÁGINAS: 270

CONTENIDO:

ANYONE WHO HAS SO MUCH GLANCED AT A NEWSPAPER OR TURNED on fue television in thee last few years knows that security is a growing concern. Burglaries occur with disgusting frequency. Then there are disasters such as fires and floods. How can you protect yourself? A good security system can certainly help. Such a system can alert you when a worrisome condicion occurs. A very simple security system is a stack of empty tin cans near the door. If an intruder comes in, he or she will knock over the cans, and the clattering noise will alert you to the intruder's presence. But modern electronics permits you to come up with security systems that are far superior and more reliable than this rather crude example. The purpose of this book is to demonstrate some of the many ways you can use electronics to protect your security and peace of mind. The main focus in this book is burglar alarms and related devices, because this area of electronic security is the one most people seem interested in today. But I also cover fire alarms and other devices designed to offer increased security against various environmental conditions. A good security system does more than simply keep out potential intruders. Certain features are common to most security systems. TlJ,ese basic elements are introduced in chapter 1; two of the most im- portant of these elements (sensors and alarm-sounding devices) are examined in somewhat more detail in the next two chapters.