Do-it-yourself phone dialer security system

Published:2012/10/19 0:46:00 Author:muriel | Keyword: Do-it-yourself phone, dialer security system | From:SeekIC

Do-it-yourself phone dialer security system calls your cell phone, office etc.whenever a door or window is opened, or panic button is pressed. Great Home Alarm.The circuit consists of a small PIC microcontroller, assembly program,and a few other parts to detect a switch closure from an open door, window,or manual push button and then dial the cell phone number, and transmit asteady tone to indicate the source of the call. The circuit uses the pulsedialing system to interrupt the line connection a number of times toindicate each digit. Pulse dialing (the oldest form of dialing) works byactually disconnecting or hanging up the phone line a number of timesto indicate each digit. For example, the digit 5 would be dialed bydisconnecting and reconnecting the line 5 times in short intervals ofabout 100mS. There is about a 1 second pause (with the line connected)between each digit. The timing is not critical and I was able to dial411 and connect to the local information service just using a momentarypush button switch in series with the phone line.



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