Homemade Burglar Alarm


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Using A Rotary Phone As A Burglar Alarm – Neatorama

He removed the receiver of his telephone and dialed all but one digit in his home telephone number. He then dialed the final digit, inserted a cork in the dial hole to keep the mechanism from returning and completing the connection.

Four strings were tied to the cork and strung at ankle level to different parts of the store.

At 2:15 a.m. Neff’s telephone roused him from a sound sleep. He lifted the receiver and heard noises, dressed and drove six blocks to a service station at Lexington and Larpenteur Avs., where he called police. August 16th, 2009 at

With todays electronic switching, even with a phone line that still accepts rotary clicks rather than tones, lines will disconnect themselves after a given period of time; you cannot be perpetually in mid dial.

In the days of electomechanical switching there would still be a physical switch waiting for that last number, but routine and regular maintenance of the system would free up the line. Because in those days, an actual electromechanical circuit representing the number, waiting for the last digit to fall, would be tied up, and capacity of the system would be hindered.

So I have to vote apocrryphal on this as well. Maybe Snopes should investigate.

Foreigner1

Homemade Alarm System

Using PIC16F84 microcontroller, motion detector (and/or smoke detector), laser barrier and cell phone.