Modular alarm system

• US 4,204,201 A
• Filed: 12/19/1978
• Issued: 05/20/1980
• Est. Priority Date: 12/19/1978
• Status: Expired due to Term

• Current Assignee: The Whitaker Corporation (Meggitt PLC)
• Original Assignee: Systron Donner Corporation
• Inventors: Pickton, Shailer T., Williams, Stewart J.
• Primary Examiner(s): Waring, Alvin H.
• Application Number:
  US05/970,922
• Time in Patent Office: 518 Days
• Field of Search: 340/500, 340/517, 340/521, 340/506, 340/52 F
• US Class Current: 340/521
• CPC Class Codes: G08B 19/00 Alarms responsive to two or more different undesired or abnormal conditions, e.g. burglary and fire, abnormal temperature and abnormal rate of flow

Abstract

A modular alarm system includes a plurality of sensing devices, each of which is adapted to sense the presence or absence of a particular condition, specifically a fire or over heat condition (hereinafter referred to merely as a fire condition), and the presence or absence of a fault including a short circuit or open circuit. The system also includes a detector module for producing an equal plurality of identical logic output signals indicative of and in response to the presence of the particular condition being monitored at the various sensing devices and a single, identical logic output signal indicative of and in response to the presence of a fault at any of the sensing devices. In addition, the system may include a main control module, a relay module and a zone module which functionally interconnect with one another and with the detector module by means of identical logic output signals and which, along with the detector module, preferably include their own power regulators and capacitive filtering systems.

Claims

1. A modulized alarm system, comprising:

(a) a plurality of sensing devices, each of which includes means for distinguishing between the presence or absence of a particular condition;

(b) a detector module connected at its input to said sensing devices and having means including logic circuitry for producing an equal plurality of identical logit output signals indicative of and in response to the presence of said condition at said sensing devices, respectively, and filter means for preventing signals of predetermined maximum duration at its input from reaching its logic circuitry;

(c) a plurality of modules different from one another and from said detector module, each of said different modules being adapted for interconnection at its input with said detector modules and the other different modules by logic output signals identical in kind to said logic output signals, each of said different modules having means including logic circuitry responsive to a logic output signal at its input for performing at least one particular function distinct from the other different modules and filter means for preventing signals of predetermined maximum duration at its input from reaching its logic circuitry; and

(d) means for powering said sensing devices and said modules including individual power regulating means associated with and connected to each of said modules for regulating power from said powering means to the logic circuitry of said associated module.

2. A modulized alarm system, comprising:

(a) a plurality of sensing devices, each of which includes

(i) first means operable between two states for distinguishing between the presence and absence of a particular condition, and

(ii) second means operable between two states for distinguishing between the presence and absence of a fault in said sensing device, including a short to ground or an open-circuit;

(b) a detector module including

(i) an equal plurality of condition sensing output terminals respectively associated with said sensing devices and a single fault sensing output terminal associated with all of said devices,

(ii) an equal plurality of means respectively cooperating with said plurality of condition distinguishing first means and respectively connected to said condition sensing terminals for producing a logic output signal at said condition sensing terminals indicative of and in response to the presence of said condition at associated sensing devices, and

(iii) an equal plurality of second means cooperating with all of said fault distinguishing second means and connected to said fault sensing terminal for producing an identical logic output signal at said fault sensing terminal indicative of and in response to the presence of a fault at any of said sensing devices; and

(c) means for powering said sending devices with said detector module.

3. A modulized alarm system, comprising:

(a) a plurality of sensing devices, each of which includes

(i) first means for distinguishing between the presence or absence of a particular condition and

(ii) second means for distinguishing between the presence or absence of a fault including a short to ground or open circuit in said sensing device;

(b) a detector module connected at its input to said sensing device and including

(i) means for producing an equal plurality of identical logic output signals indicative of and in response to the presence of said condition at said sensing devices, respectively, and

(ii) means for producing a single logic output signal, identical to said plurality of logic output signals, in response to the presence of a fault at any of said sensing devices;

(c) a plurality of modules different from one another and from said detector module, each of said different modules being adapted for interconnection at its input with said detector modules and the other different modules by logic output signals identical in kind to said logic output signals and being responsive to a logic output signal at its input for performing at least one particular function distinct from the other different modules; and

(d) means for powering said sensing devices and said modules.

4. A system according to claim 3 wherein each of said modules includes logic circuitry and individual means connected with said powering means for regulating the power to this logic circuitry.

5. A system according to claim 4 wherein each of said modules includes its own capacitive filter means for preventing electrical signals of predetermined maximum duration at its input from reaching its logic circuitry.

6. A system according to claim 3 wherein said different modules include a main control module having at least one output terminal and including means for producing at said terminal an alarm driving power signal adapted to drive an external alarm in response to the presence of said logit output signals.

7. A system according to claim 3 wherein said different modules includes a switch module having at least one output terminal and control means including at least one switch operable between an on or off state, said control means actuating said switch in response to the presence of said logic output signal for producing a signal at said last-mentioned output terminal for driving an external apparatus.

8. A system according to claim 7 wherein said switch is an electromagnetic relay including a coil and at least one contact, said apparatus driving signal being applied through one of said contacts.

9. A system according to claim 8 including means for applying a logic signal indicative of a test condition at the input of said relay coil whereby to energize the latter and means for disabling said driving signals during application of said test signal even though such coil is energized.

10. A system according to claim 3 wherein said different modules includes a zone module having at least one output terminal and including circuit delay means for producing an identical logic output signal at said one output terminal in response to but an adjustably fixed period of time after the initial presence of said logic output signal.

11. A system according to claim 10 wherein said circuit delay means includes by-pass means for producing said delayed logic output signal at said last-mentioned terminal a pre-set period of time after the initial presence of said logic output signal, said preset period of time being different than said adjustably fixed period of time.

12. A system according to claim 3 wherein said different modules include a zone module having an output terminal and including means for producing an identical output signal at said last-mentioned output terminal in response to the presence of a predetermined adjustable combination of said logic output signals.

13. A system according to claim 3 wherein each of said first means includes latching means having a memory circuit for maintaining said condition indicating logic output signal in said memory circuit after said last mentioned output signal has been produced and means for producing said memory maintained logic output signal at an associated output terminal at a later time.

14. A modulized alarm system, comprising:

(a) power supply means;

(b) a plurality of sensing devices, each of which includes

(i) first means operable between two states for distinguishing between the presence and absence of a particular condition, and

(ii) second means operable between two states for distinguishing between the presence and absence of a fault in said sensing device, including a short to ground or an open-circuit

(c) a detector module including

(i) an equal plurality of condition sensing output terminals respectively associated with said sensing devices and a single fault sensing output terminal associated with all of said devices

(ii) means including logic circuitry respectively cooperating with said plurality of condition distinguishing first means and respectively connected to said condition sensing terminals for producing a logic output signal at said condition sensing terminals indicative of and in response to the presence of said condition at associated sensing devices

(iii) an equal plurality of second means cooperating with all of said fault distinguishing second means and connected to said fault sensing terminal for producing an identical logic output signal at said fault sensing terminal indicative of and in response to the presence of a fault at any of said sensing devices,

(iv) capacitive filter means adapted for connection with each of said sensing devices and connected with an associated cooperating means for preventing electrical signals of at most 0.1 to 10 second duration at said associated sensing device from reaching said cooperating means, and

(v) means adapted for connection with said power supply means and connected with all of said cooperating means for regulating the power to the logic circuitry of each cooperating means;

(d) a main control module including

(i) at least one output terminal,

(ii) means including logic circuitry for producing at said main control output terminal an alarm driving power signal adapted to drive an external alarm in response to the presence of said logic output signal at its input,

(iii) capacitive filter means at its input for preventing electrical signals of at most 0.001 to 1 second duration at said input from reaching its logic circuitry, and

(iv) means adapted for connection with said power supply means for regulating the power to its logic circuitry

(e) a relay module having at least one output terminal and including

(i) control means including logic circuitry and at least one electromagnetic relay including a coil and contacts operable between an energized state and a de-energized state, said control means energizing said relay coil in response to the presence of said logic output signal at its input for producing a signal through at least one of said contacts for driving an external apparatus

(ii) capacitive filter means at said last-mentioned input for preventing electrical signals of at most 0.001 to 1 second duration at said last mentioned input from reaching said last-mentioned circuitry, and

(iii) means adapted for connection with said power supply means for regulating the power to the last-mentioned logic circuitry; and

(f) a zone module having at least two output terminals and including

(i) signal combining means including logic circuitry for producing an identical output signal at said one of said last-mentioned output terminals in response to the presence of a predetermined adjustable combination of logic output sitnals

(ii) delay means including logic circuitry for producing an identical logic output signal at the other of said last-mentioned output terminals in response to but an adjustably fixed period of time after the initial presence of said logic output signal

(iii) capacitive filter means adapted for preventing electrical signals of at most 0.001 to 1 second duration at the inputs of said signal combining means and said delay means from reaching the logic circuitry of each of said last-mentioned means, and

(iv) means adapted for connection with said power supply means and connected with said signal combining means and said delay means for regulating the power to the logic circuitry of each of said last-mentioned means.