Low power audible alarm relay device for a rolling code security system

• US 6,359,558 B1
• Filed: 11/22/1999
• Issued: 03/19/2002
• Est. Priority Date: 02/13/1998
• Status: Expired due to Fees

• Current Assignee: Tsui, Philip Y. W.
• Original Assignee: Tsui, Philip Y. W.
• Inventors: Tsui, Philip Y. W.
• Primary Examiner(s): Crosland, Donnie L.
• Application Number:
  US09/447,389
• Time in Patent Office: 848 Days
• Field of Search: 340/531, 340/539, 340/566, 367/197-199
• US Class Current: 340/531
• CPC Class Codes: G08B 25/009 Signalling of the alarm condition to a substation whose identity is signalled to a central station, e.g. relaying alarm signals in order to extend communication range

Abstract

An alarm relay device including a microphone that produces a signal responsive to an audible alarm having a frequency. A first circuit coupled to the microphone produces a first detect signal when the signal is above a predetermined level. A second circuit coupled to the microphone and the first circuit receives power responsive to the first detect signal. The second circuit produces a second detect signal when the signal is within a predetermined range of the frequency.

Claims

1. An alarm relay device comprising:

a microphone producing a signal responsive to an audible alarm having a frequency;

a first circuit coupled to the microphone, said first circuit producing a first detect signal when the signal is above a predetermined level; and

a second circuit coupled to the microphone and the first circuit, said second circuit receiving power responsive to the first detect signal and producing a second detect signal when the signal is within a predetermined range of the frequency.

2. The alarm relay device of claim 1, further comprising a voltage regulator coupled to the first circuit and the second circuit, said voltage regulator being turned on by the first detect signal, and providing power to the second circuit.

3. The alarm relay device of claim 1, further comprising a third circuit coupled to the microphone and the second circuit;

said third circuit turning off the microphone for a predetermined length of time responsive to the second detect signal.

4. The alarm relay device of claim 1, further comprising a fourth circuit coupled to the second circuit;

said fourth circuit receiving power responsive to the first detect signal and the second detect signal, and transmitting a signal responsive to the second detect signal.

5. The alarm relay device of claim 4, further comprising:

a memory coupled to the fourth circuit, said memory storing a device code to be transmitted by the fourth circuit, said device code including a predetermined identification code and a variable code, said variable code having a first value; and

a fifth circuit coupled to the fourth circuit and the memory, said fifth circuit storing a second value for the variable code in the memory responsive to the fourth circuit transmitting the device code, where the second value is based on the first value.

6. The alarm relay device of claim 4, further comprising:

a voltage regulator coupled to the first circuit, the second circuit, and the fourth circuit, said voltage regulator being turned on by the first detect signal and providing power to the second circuit and the fourth circuit; and

a ground switch coupled to the second circuit and the fourth circuit, said ground switch connecting the fourth circuit to ground responsive to the second detect signal.

7. The alarm relay device of claim 1, wherein the frequency is adjustable to respond to a local audible signal.

8. The alarm relay device of claim 1, wherein the microphone has a sensitivity that is adjusted to respond to the audible alarm at a predetermined level.

9. A alarm relay device comprising:

a microphone producing a signal responsive to an audible alarm having a frequency;

a first circuit coupled to the microphone, said first circuit producing a detect signal when the signal is within a predetermined range of the frequency;

a memory that stores a device code, said device code including a predetermined identification code and a variable code, said variable code having a first value;

a second circuit coupled to the first circuit and the memory, said second circuit transmitting the device code responsive to the detect signal; and

a third circuit coupled to the second circuit and the memory, said third circuit storing a second value for the variable code in the memory responsive to the second circuit transmitting the device code, where the second value is based on the first value.

10. The alarm relay device of claim 9, further comprising a fourth circuit coupled to the second circuit, said fourth circuit causing the second circuit to transmit the device code when the detect signal is continuously received for more than a predetermined period of time.

11. The alarm relay device of claim 10, further comprising a fifth circuit coupled to the first circuit, said fifth circuit to maintain the detect signal during a short period of time when the signal is below the predetermined level.

12. The alarm relay device of claim 11, wherein at least one of the first circuit, the second circuit, the third circuit, the fourth circuit, and the fifth circuit is a microcontroller.

13. A security system comprising:

an alarm relay device including

a microphone producing a signal responsive to an audible alarm having a frequency,

a first circuit coupled to the microphone, said first circuit producing a first detect signal when the signal is above a predetermined level, and

a second circuit coupled to the microphone and the first circuit, said second circuit receiving power responsive to the first detect signal and transmitting a second detect signal when the signal is within a predetermined range of the frequency; and

a security console including

a receiver to receive the second detect signal,

an alarm circuit coupled to the receiver, said alarm circuit signaling presence of the audible alarm when the second detect signal is received.

14. The security system of claim 13, wherein the alarm relay device further includes a voltage regulator coupled to the first circuit and the second circuit, said voltage regulator being turned on by the first detect signal, and providing power to the second circuit.

15. The security system of claim 13, wherein the alarm relay device further includes a third circuit coupled to the microphone and the second circuit;

said third circuit turning off the microphone for a predetermined length of time responsive to the second detect signal.

16. The security system of claim 13, wherein the alarm relay device further includes a fourth circuit coupled to the second circuit;

said fourth circuit receiving power responsive to the first detect signal and the second detect signal, and transmitting a signal responsive to the second detect signal.

17. The security system of claim 16, wherein the alarm relay device further includes

a memory coupled to the fourth circuit, said memory storing a device code to be transmitted by the fourth circuit, said device code including a predetermined identification code and a variable code, said variable code having a first value, and

a fifth circuit coupled to the fourth circuit and the memory, said fifth circuit storing a second value for the variable code in the memory responsive to the fourth circuit transmitting the device code, where the second value is based on the first value.

18. The security system of claim 16, wherein the alarm relay device further includes

a voltage regulator coupled to the first circuit, the second circuit, and the fourth circuit, said voltage regulator being turned on by the first detect signal and providing power to the second circuit and the fourth circuit, and

a ground switch coupled to the second circuit and the fourth circuit, said ground switch connecting the fourth circuit to ground responsive to the second detect signal.

19. The security system of claim 13, wherein the frequency is adjustable to respond to a local audible signal.

20. The security system of claim 13, wherein the microphone has a sensitivity that is adjusted to respond to the audible alarm at a predetermined level.

21. A security system comprising:

an alarm relay device including

a microphone producing a signal responsive to an audible alarm having a frequency,

a first circuit coupled to the microphone, said first circuit producing a detect signal when the signal is within a predetermined range of the frequency,

a memory that stores a first device code, said first device code including a predetermined identification code and a variable code, said variable code having a first value,

a second circuit coupled to the first circuit and the memory, said second circuit transmitting the first device code responsive to the detect signal, and

a third circuit coupled to the second circuit and the memory, said third circuit storing a second value for the variable code in the memory responsive to the second circuit transmitting the first device code, where the second value is based on the first value;

a security console including

a console memory that stores a second device code, said second device code including a second predetermined identification code and a second variable code, said second variable code having a third value,

a receiver to receive the first device code,

an alarm circuit coupled to the receiver, said alarm circuit signaling an alarm condition if the first device code matches the second device code;

a code update circuit coupled to the alarm circuit and the console memory, said code update circuit storing a fourth value for the second variable code in the console memory responsive to the alarm circuit signaling an alarm condition, where the fourth value is based on the third value.

22. The alarm relay device of claim 21, wherein the alarm relay device further includes a fourth circuit coupled to the second circuit, said fourth circuit causing the second circuit to transmit the first device code when the detect signal is continuously received for more than a predetermined period of time.

23. The alarm relay device of claim 22, wherein the alarm relay device further includes a fifth circuit coupled to the first circuit, said fifth circuit to maintain the detect signal during a short period of time when the signal is below the predetermined level.

24. The alarm relay device of claim 23, wherein at least one of the first circuit, the second circuit, the third circuit, the fourth circuit, and the fifth circuit is a microcontroller.

25. A method of transmitting a local audible signal to a security console, comprising:

detecting a signal having a frequency from a microphone when the signal is above a predetermined level;

providing power to a tone detector circuit when the signal is detected;

detecting a tone when the signal is within a predetermined range of the frequency; and

providing power to a code transmitter when the tone is detected for a predetermined length of time; and

transmitting a code to the security console with the code transmitter while power is provided to the code transmitter.

26. The method of claim 25, further comprising turning off the microphone for a predetermined length of time when the tone is detected.

27. The method of claim 25, wherein transmitting the code further includes

storing the code to be transmitted, said code including a predetermined identification code and a variable code, said variable code having a first value, and

storing a second value for the variable code after transmitting the code, where the second value is based on the first value.

28. The security system of claim 25, further comprising adjusting the frequency to respond to a local audible signal.

29. The security system of claim 25, further comprising adjusting the predetermined level to respond to the audible alarm.

30. A method of transmitting a local audible signal to a security console, comprising:

storing a device code in a memory, said device code including a predetermined identification code and a variable code, said variable code having a first value;

detecting a signal from a microphone when the signal is within three percent of a predetermined frequency;

transmitting the device code when the signal is detected;

storing a second value for the variable code in the memory after the second circuit transmits the device code, where the second value is based on the first value.

31. The method of claim 30, further comprising transmitting the device code when the signal is continuously detected for more than five seconds.

32. The method of claim 30, further comprising transmitting the device code when the signal is continuously detected for more than five seconds without any interruptions that are longer than one-half second.