EVENT SIGNAL TRANSMITTER HAVING EVENT SIGNAL DISPLAYING MEANS

• US 3,772,667 A
• Filed: 11/15/1971
• Issued: 11/13/1973
• Est. Priority Date: 11/15/1971
• Status: Expired due to Term

• Current Assignee: Melvin S. Falck Jr
• Original Assignee: Melvin S. Falck Jr
• Inventors: Falck, Melvin S. Jr.
• Primary Examiner(s): Pitts, Harold I.
• Application Number:
  US05/198,543
• Time in Patent Office: 729 Days
• Field of Search: 340/216R,416R,233R,217R
• US Class Current: 340/514
• CPC Class Codes: G08B 25/08 using communication transmission lines G08B13/19658, G08B21/0286, G08B25/016 take precedence

Abstract

An event signal transmitter for use in an alarm system in which a number of similar transmitters are commonly connected on a single transmission line to a central office. The transmitter is programmable by means of switches to provide a plurality of modes of operation. Alarm and clear events are signaled to the central office by transmitting a predetermined number of rounds of a three digit code number set on a switch matrix. A closing sequence may be selectively employed to reduce undesirable transmission while the protected premises are being closed. An exit delay timer may also be used for this purpose. A line monitor prevents simultaneous transmission by more than one transmitter and a hold out timing period for the monitor is dependent on the time of the occurrence of an event at the transmitter. An override function prevents the transmitter from being indefinitely inhibited from transmitting. A test function is included to determine the condition of sensors before the transmitter is turned on. The power to all circuitry not needed to monitor the sensors or transmission line is turned off until an event signal is to be transmitted.

Claims

1. An event signal transmitter for common connection to a transmission line with a plurality of other transmitters, said transmitter comprising:

event sensing means for sensing a plurality of different events;

event signal generating means for generating event signals corresponding to said events;

control means connected to said sensing means and to said generating means for controlling transmission of said event signals over said transmission lines;

line monitoring means connected to said control means and to said transmission line for sensing activity on said transmission line, said monitoring means generating a lineactive signal in the presence of line activity and a line-open signal a first predetermined time period after the cessation of such activity, said monitoring means further having an event signal delay means for delaying a generated event signal for a second predetermined time period to produce a delayed event signal, and a delay clock means for generating delay clock pulses in response to generation of said event signal, transmission of said event signal being inhibited by said lineactive signal and transmission being initiated upon coincidence of said line-open signal and said event signal or said lineopen signal, said delayed event signal and a delay clock pulse.

2. The event signal transmitter defined in claim 1 including:

mode selection means connected to said control means for preselecting a plurality of sequences of event signals to be generated in response to particular sequences of sensing of events by said sensing means.

3. The event signal transmitter defined in claim 1 including:

controlled power supply means for selectively supplying power to said event signal generating means and said event signal delay means, said controlled power supply means being under the control of said control means.

4. The event signal transmitter defined in claim 1, wherein said event sensing means includes:

a bridge circuit with individual sensors in legs of said bridge circuit; and

feedback means connected to said bridge circuit for providing a threshold type event signal when an event is sensed.

5. The event signal transmitter as defined in claim 1 wherein:

said event signal delay means further delays said event signal for a third predetermined time period longer than said second predetermined time period, an override signal being generated at the end of said third predetermined time period to initiate transmission of said event signal despite the presence of said line-active signal.

6. The event signal transmitter defined in claim 5 including:

controlled power supply means for selectively supplying power to said event signal generating means and said event signal delay means, said controlled power supply means being under the control of said control means.

7. The event signal transmitter defined in claim 6 wherein said event sensing means includes:

a bridge circuit with individual sensors in legs of said bridge circuit; and

feedback means connected to said bridge circuit for providing a threshold type event signal when an event is sensed.

8. The event signal transmitter as defined in claim 1 including:

mode selection means for preselecting a plurality of modes of operation for said transmitter, said modes being defIned as the selective inhibition of the transmission of particular sequences of event signals.

9. The event signal transmitter defined in claim 8, including:

controlled power supply means for selectively supplying power to said event signal generating means and said event signal delay means, said controlled power supply means being under the control of said control means.

10. The event signal transmitter defined in claim 9 wherein:

said event signal delay means further delays said event signal for a third predetermined time period longer than said second predetermined time period, an override signal being generated at the end of said third predetermined time period to initiate transmission of said event signal despite the presence of said line-active signal.

11. The event signal transmitter defined in claim 10, wherein said event sensing means includes:

a bridge circuit with individual sensors in legs of said bridge circuit; and

feedback means connected to said bridge circuit for providing a threshold type event signal when an event is sensed.

12. An event signal transmitter for use in an alarm system in which a plurality of transmitters are commonly connected on a single transmission line to a central office, said transmitter comprising:

event sensing means for sensing an alarm or a clear condition;

event signal generating means for generating an alarm or a clear signal, and transmitting said alarm or clear signal to said central office, said alarm signal being defined as the transmission of a code number for said transmitter a first predetermined number of rounds and said clear signal being defined as the transmission of said code number a second predetermined number of rounds;

control means connected to said event sensing means and said event signal generating means for controlling transmission of said event signals over said transmission line;

line monitoring means connected to said control means and to said transmission line for sensing activity on said line, said monitoring means generating a line-active signal in the presence of line activity and a line-open signal a first predetermined time period after the cessation of such activity;

event signal delay means for delaying transmission of a generated event signal for a second predetermined time period to produce a delayed event signal, and a delay clock means for generating delay clocl clock pulses in response to said delayed event signal, transmission of said event signal being inhibited by said line-active signal and transmission being initiated upon coincidence of said line-open signal and said event signal or said line-open signal, said delayed event signal and a delay clock pulse.

13. The event signal generating means defined in claim 12, including:

controlled power supply means for selectively supplying power to said event signal generating means and to said event signal delay means, said controlled power supply means being controlled by said control means.

14. The event signal transmitter defined in claim 12, wherein said control means includes:

control switch means for selectively providing OFF, TEST and ON operation positions for said transmitter, said OFF position forcing said transmitter into an alarm condition, the alarm or clear condition of said transmitter being displayed in said TEST position and the transmitter being made operational in said ON position.

15. The event signal transmitter defined in claim 14 wherein said control means includes:

mode switch means for selectively providing first, second and third operating modes for said transmitter when said control switch means is in said ON position, said first mode permitting the transmission of all alarm or clear signals, said second mode inhibiting the transmission of an initial clear signal and alarm signal when said control switch means is put into said ON position and thereafter permitting the transmission of all alarm or clear signals and said third moDe inhibiting the transmission of an initial clear signal and alarm signal when said control switch means is put into said ON position and thereafter permitting the transmission of only one alarm signal.

16. The event signal transmitter defined in claim 15 wherein:

said event signal delay means further delays said event signal for a third predetermined time period longer than said second predetermined time period, an override signal being generated at the end of said third predetermined time period to initiate transmission of said event signal despite the presence of said line-active signal.

17. The event signal transmitter defined in claim 16 including:

controlled power supply means for selectively supplying power to said event signal generating means and to said event signal delay means, said controlled power supply means being controlled by said control means.

18. The event signal transmitter defined in claim 14 wherein said event signal generating means includes:

clear signal selector switch means for preselecting said second predetermined number of rounds.

19. The event signal transmitter defined in claim 18 wherein:

said second predetermined number of rounds may be selected as one or two rounds, said first predetermined number being three rounds.

20. The event signal transmitter defined in claim 18 wherein said event signal generating means includes:

means for opening the circuit of said transmission line through said transmitter;

means for shorting said transmission line to ground; and

sequence selection switch means for preselecting sequence of opening and shorting said transmission line.

21. The event signal transmitter defined in claim 20 including:

controlled power supply means for selectively supplying power to said event signal generating means and to said event signal delay means, said controlled power supply means being controlled by said control means.

22. The event signal transmitter defined in claim 20 wherein:

said event signal delay means further delays said event signal for a third predetermined time period longer than said second predetermined time period, an override signal being generated at the end of said third predetermined time period to initiate transmission of said event signal despite the presence of said line-active signal.

23. The event signal transmitter defined in claim 22 wherein said control switch means further includes:

mode switch means for selectively providing first, second and third operating modes for said transmitter when said control switch means is in said ON position, said first mode permitting the transmission of all alarm or clear signals, said second inhibiting the transmission of an initial clear signal and alarm signal when said control switch means is put into said ON position and thereafter permitting the transmission of all alarm or clear signals and said third mode inhibiting the transmission of an initial clear signal and alarm signal when said control switch means is put into said ON position and thereafter permitting the transmission of only one alarm signal.

24. The event signal transmitter defined in claim 23 including:

controlled power supply meand for selectively supply power to said event signal generating means and to said event signal delay means, said controlled power supply means being controlled by said control means.

25. The event signal transmitter defined in claim 24 wherein said event sensing means includes:

a bridge circuit with individual sensors in legs of said bridge circuit; and

feedback means connected to said bridge circuit for providing a threshold type event signal when an event is sensed. feedback means connected to said bridge circuit for providing a threshold type event signal when an event is sensed.