Neighborhood home security system

• US 4,731,810 A
• Filed: 02/25/1986
• Issued: 03/15/1988
• Est. Priority Date: 02/25/1986
• Status: Expired due to Fees

• Current Assignee: Randy W. Watkins
• Original Assignee: Randy W. Watkins
• Inventors: Watkins, Randy W.
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US06/832,697
• Time in Patent Office: 749 Days
• Field of Search: 179/2 A, 179/2.51, 179/5 R, 179/5 P, 179/27 G, 340/310 A, 340/310 R, 340/538, 379/32, 379/33, 379/37, 379/39, 379/40, 379/41, 379/44, 379/50, 379/51, 379/66, 379/106
• US Class Current: 379/33
• CPC Class Codes: G08B 25/06 using power transmission lines
• CPC Class Codes: H04B 2203/5437 Wired telephone
• CPC Class Codes: H04B 2203/5466 using three phases conductors
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04M 11/04 with alarm systems, e.g. fire, police or burglar alarm systems

Abstract

A backup security system for the telephone company lines of a protected home located in a neighborhood in which all the homes have a.c. supply lines connected to a common power transformer. The protected home, in addition to being provided with a conventional security system, is provided with a line-cut monitor, a PWM transmitter, and a conflict avoidance circuit. When the line-cut monitor senses that the telephone company lines for the protected home have been cut by an intruder, it provided a signal for gating an alarm signal from the conventional security system to the PWM transmitter which impresses the alarm signal as high frequency signals on the a.c. supply lines in the neighborhood. A neighboring home in the neighborhood is provided with a PWM receiver, telephone company lines and an automatic telelphone communicator. The PWM receiver in the neighboring home responds to the high frequency signals on the a.c. supply lines and provides a digital signal to the automatic telephone communicator causing it to seize the telephone company lines for the neighboring home and send a message informing a central station that an intruder has broken into the protected home. The conflict avoidance circuit in the protected home enables the PWM transmitter therein to impress high frequency signals on the a.c. supply lines in the neighborhood only when there is an absence of any other high frequency signals on the a.c. supply lines in the neighborhood.

Claims

1. A backup security system for the telephone company lines of a protected home located in a neighborhood of individual homes all having external a.c. supply lines connected to a common power transformer and each having individual external telephone company lines, said system comprising:

a line-cut monitor in the protected home for providing a signal when the external telephone company lines for the protected home have been cut;

a transmitter means in the protected home responsive to the signal from the line-cut monitor for providing high frequency electrical signals on the a.c. supply lines; and

a receiver means and an automatic telephone communicator located in one of the other homes in the neighborhood selected to serve as a backup home;

said receiver means responding to the high frequency electrical signals on the a.c. supply lines and providing a signal to said automatic telephone communicator to seize the telephone company lines for the backup home and send a message informing a central station that the telephone company lines for the protected home have been cut.

2. A backup security system for the telephone company lines of a protected home located in a neighborhood of individual homes wherein all the homes have external a.c. supply lines connected to a common power transformer and each of the homes has its own external telephone company lines, said system comprising:

a line-cut monitor in the protected home for providing a signal when the external telephone company lines for the protected home have been cut;

an alarm panel in the protected home for providing a signal when an intruder breaks therein;

a transmitter means in the protected home responsive to the signals from the line-cut monitor and the alarm panel for providing high frequency electrical signals on the a.c. supply lines; and

a receiver means and an automatic telephone communicator in one of the other homes in the neighborhood selected to serve as a backup home;

said receiver means responding to the high frequency electrical signals on the a.c. supply lines and providing a signal to said automatic telephone communicator to seize the telephone company lines for the backup home and send a message informing a central station that an intruder has broken into the protected home.

3. A backup security system for the telephone company lines of a protected home located in a neighborhood of individual homes wherein all the homes have external a.c. supply lines connected to a common power transformer and each of the homes has its own external telephone company lines, said system comprising:

a sensor means in the protected home for providing a signal when the telephone company lines for the protected home are inoperable;

security means in the protected home for providing a signal when emergency assistance is needed;

a transmitter means in the protected home responsive to the signal from the security measn when the sensor means provides a signal to transmit high frequency electrical signals on the a.c. supply lines; and

a receiver means and an automatic telephone communicator located in another home in the neighborhood selected to serve as a backup home;

said receiver means responding to the high frequency electrical signals on the a.c. supply lines and providing a signal to said automatic telephone communicator to seize the telephone company lines for the backup home and send a message informing a central station that emergency assistance is needed in the protected home.

4. A backup security system for the telephone company lines of a protected home located in a neighborhood of individual homes wherein all the homes have external a.c. supply lines connected to a common power transformer and each of the homes has its own external telephone company lines, said system comprising:

a line-cut monitor in the protected home for providing a signal when the telephone company lines for the protected home have become inoperable;

security means in the protected home for generating an alarm signal when the protected home has been broken into by an intruder;

a transmitter means in the protected home;

a gating means responsive to said signal from the line-cut monitor for gating said alarm signal into said transmitter means;

said transmitter means providing for transmitting width modulated bursts of high frequency electrical signals corresponding to an address of said protected home and the alarm signal on said a.c. supply lines; and

a receiver means and an automatic telephone communicator in any other home in said neighborhood selected for use as a backup home;

said receiver means storing the address of said protected home; and

said receiver means responding to the width modulated bursts of high frequency electrical signals on the a.c. supply lines and when the address stored therein compares with the address of the protected home providing a digital alarm signal on the output thereof;

said automatic telephone communicator responding to the digital alarm signal to seize the telephone company lines for the backup home to send out a message informing a central station that the protected home has been broken into by an intruder.

5. A backup security system for the telephone company lines of a protected home as defined in claim 4 including:

a control circuit means associated with said transmitter means in the protected home for preventing the transmitter means from transmitting any bursts of high frequency electrical signals on the a.c. supply lines in the neighborhood until the a.c. supply lines are clear of any high frequency electrical signals.

6. A backup security system for the telephone company lines of a protected home as defined in claim 4 wherein the security means in the protected home also provides a signal indicating whether it is armed and the armed signal is transmitted by said transmitter means as a burst of high frequency electrical signals on the a. c. supply lines;

wherein the alarm signal and armed signal are stored in latching means provided in said receiver means; and

wherein the receiver means in the backup home detects an absence of the receipt of any signals from the transmitter means indicative of supervision being bad in the protected home and combines this information with the armed data in the latching means to provide a supervision bad armed signal or a supervision bad unarmed signal to the automatic telephone communicator.

7. A backup security system for the telephone company lines of a protected home located in a neighborhood as defined in claim 5 wherein said control circuit means includes:

a timing flipflop for use in measuring a fixed time interval;

a first timing capacitor which charges to a level to reset said timing flipflop in said fixed time interval;

a control circuit coupled to the a.c. supply lines to provide a busy indicating signal if any high frequency signals are present thereon;

a threshold inverter circuit;

a threshold capacitor which when charged to a high threshold voltage provides for switching said threshold inverter circuit to a low voltage level which enables said transmitter means to start transmitting said high frequency signals and simultaneously provides for setting said timing flipflop to gradually start charging said first timing capacitor and gradually start discharging said threshold capacitor and holding the latter discharged for said fixed timing interval after which time said first timing capacitor charges to said level to reset said timing flipflop and start charging said threshold capacitor again;

said threshold capacitor prevented from charging to a high threshold voltage by being discharged if a busy indicating signal is sensed by said control circuit prior to reaching said high threshold voltage and remaining discharged until said busy indicating signal disappears.

8. A backup security system for the telephone company lines of each of a plurality of protected homes located in a neighborhood of individual homes wherein all the homes have external a.c. supply lines connected to a common power transformer and each of the individual homes has its own external telephone company lines, said system comprising:

an automatic telephone communicator means and a receiver means located in a backup home provided in the neighborhood for each protected home, each said receiver means storing an address signal of the protected home;

a line-cut monitor in each protected home for providing a signal when the external telephone company lines for the protected home have been cut;

a transmitter means in each protected home responsive to the signal from the line-cut monitor therein for providing electrical signals on the a.c. supply lines, said electrical signals including the address signal of the protected home and the signal from the line-cut monitor;

said receiver means in each said backup home responding to said electrical address signal transmitted on the a.c. supply lines and upon comparison with the address signal stored therein causes the automatic telephone communicator means in said backup home to seize the telephone company lines therefor and send an emergency message to a central station advising that the telephone company lines for the protected home have been cut.

9. A backup security system for a protected home located in a neighborhood of individual homes wherein all the homes have external a.c. supply lines connected to a common power transformer and each of the homes has its own external telephone company lines, said system comprising:

an alarm panel, a first automatic telephone communicator, a line-cut monitor, and a transmitter means at the protected home;

a receiver means and a second automatic telephone communicator at a neighboring home in the neighborhood selected to serve as a backup home;

said line-cut monitor providing a signal when the external telephone company lines at the protected home have been cut;

said alarm panel operable when an intruder breaks into the protected home and the line-cut monitor does not provide a signal indicating the telephone company lines for the protected home have been cut to provide a signal to said first automatic telephone communicator causing it to seize the telephone company lines at the protected home and send a message informing a central station of the intrusion into the protected home;

said alarm panel operable when an intruder breaks into the protected home and line-cut monitor provides a signal indicating the telephone company lines for the protected home have been cut to provide a signal to said transmitter means causing it to transmit high frequency electrical signals on the a.c. supply lines; and

said receiver means at the neighboring home responding to the high frequency electrical signals on the a.c. supply lines to provide a signal to said second automatic telephone communicator causing it to seize the telephone company lines at the neighboring home and send a message informing the central station of the intrusion into the protected home.