Apparatus for activating or deactivating an intrusion detection system from a plurality of remote locations

• US 4,156,235 A
• Filed: 03/23/1978
• Issued: 05/22/1979
• Est. Priority Date: 03/23/1978
• Status: Expired due to Term

• Current Assignee: Napco Security Systems Incorporated
• Original Assignee: Napco Security Systems Incorporated
• Inventors: Stockdale, Roy
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/889,256
• Time in Patent Office: 425 Days
• Field of Search: 340/500, 340/541, 340/652, 340/654
• US Class Current: 340/541
• CPC Class Codes: G08B 25/008 Alarm setting and unsetting, i.e. arming or disarming of the security system

Abstract

An intrusion detection system can be armed and disarmed from a plurality of remote locations by the use of a plurality of momentary switches, each one associated with one of said locations. Each switch when depressed, functions to change the state of a flip/flop. The flip/flop in one mode operates to disarm the intrusion detection system. When the flip/flop is in its other mode, the intrusion detection system is armed and activated. The apparatus monitors the state of the control loop associated with the detection system in order to indicate to a user that the system can be activated or armed when desired. If the control loop is not secure, the apparatus will indicate this fact to the user to enable him to secure the loop before arming the system by triggering of the flip/flop.

Claims

1. In an intrusion detection system of the type operative to monitor an intrusion on a secured premises, said intrusion detection system operating to detect an open circuit in a loop of detector devices, which loop is normally closed when the premises are secured said intrusion detection system having an input terminal for arming said system upon application of a first signal thereto and for disarming said system for application of a second signal thereto, the combination therewith of apparatus for arming or disarming said system, comprising:

(a) first means coupled to said loop and operative to provide at an output a first status signal when said loop is closed and a second status signal when said loop is opened,

(b) a first momentary switch adapted when operated to provide a pulse at an output,

(c) a bistable multivibrator having an input terminal, and a first and second output terminal, said first output terminal coupled to said input terminal of said detection system operative to provide said first signal when said multivibrator is operated in a first state and said second signal when said multivibrator is operated in a second state, said second output terminal adapted to provide a signal indicative of said second signal when said multivibrator is operated in said first state and a signal indicative of said first signal when said multivibrator is operated in said second state,

(d) logic means having one input terminal coupled to said output of said first means and a second input coupled to said second terminal of said bistable, to provide an output signal during the presence of said first status signal and for said bistable operated in said first mode, said output signal indicative of said loop being closed and said intrusion system being disarmed,

(e) means coupling said output of said momentary switch to said input terminal of said bistable to alter said states of said bistable according to the operation of said momentary switch to therefore selectively arm or disarm said system according to said output signal as provided by said logic means.

2. The system according to claim 1 wherein said means coupling said momentary swtich output to said input of said bistable includes an integrator circuit operative to discriminate against undesirable contact bounce associated with said momentary switch.

3. The system according to claim 1 further including a first indicator means coupled to said output of said logic means to provide an indication of the presence of said output signal.

4. The system according to claim 1 further including second indicator means coupled to said second output terminal of said bistable to provide an indication when said intrusion system is armed due to the presence of said first signal at said input terminal of said intrustion detection means as coupled to said bistable.

5. The system according to claim 1 further including another momentary switch in parallel with said first momentary swtich and operative to alter the states of said bistable independent of said operation of said first switch.

6. The system according to claim 3 wherein said first indicator means includes a green colored lamp.

7. The system according to claim 4 wherein said second indicator means includes a red colored lamp.

8. The system according to claim 1 wherein said means coupling said output of said first momentary switch to said input terminal of said bistable includes a second multivibrator operating in a set/reset mode to provide a predetermined pulse each time said switch is operated.

9. The system according to claim 1 wherein said intrusion detection system is a fire detection system.

10. The system according to claim 1 wherein said intrusion detection system is a burglary detection system.