SUPPLEMENTAL ALERT GENERATION DEVICE

• US 20110193714A1
• Filed: 02/09/2010
• Published: 08/11/2011
• Est. Priority Date: 02/09/2010
• Status: Active Grant

• Current Assignee: InnovAlarm Corporation
• Original Assignee: InnovAlarm Corporation
• Inventors: Lewis, James J., Albert, David E., Smith, Landgrave T.
• Granted Patent: US 8,237,577 B2
• Time in Patent Office: Days
• US Class Current: 340/635
• CPC Class Codes: G08B 1/08 using electric transmission ; transformation of alarm signals to electrical signals from a different medium, e.g. transmission of an electric alarm signal upon detection of an audible alarm signal

Abstract

A battery-powered supplemental alert generator is disclosed that is adapted to be mounted in close proximity to, such as within 3 or 4 feet of, a conventional smoke, heat and/or fire detector/alert device. The supplemental alert generator operates in a relatively low power mode while listening for the nearby detector/alert device to generate a standard audible alert signal. Upon detecting that a monitored sound level has reached a particular threshold, the supplemental alert generator enters into a higher power analysis mode in which it analyzes the detected signal to assess whether it is an audible alert signal. If an audible alert signal is detected, the supplemental alert generator generates one or more supplemental alert signals, such as a 520 Hz audible square wave signal. The supplemental alert generator may be used to retrofit a house, hotel, or other building to comply with new standards or to otherwise increase the effectiveness of the existing detection/alert system.

Claims

1. A supplemental alert generation device for supplementing an audible alert signal generated by a detector/alert device, the supplemental alert generation device comprising:

a threshold sound level detector operative to generate a notification signal when a monitored sound level exceeds a threshold sound level; and

a controller that is responsive to the notification signal by transitioning out of a sleep mode into a signal analysis mode in which the controller determines whether a sound detected by the supplemental alert generation device is an audible alert signal, said controller programmed to initiate generation of a supplemental alert signal when said sound is determined to be an audible alert signal.

2. The supplemental alert generation device of claim 1, wherein the threshold sound level is at least 70 dBA.

3. The supplemental alert generation device of claim 1, wherein the threshold sound level detector is adjustable by the controller to vary a threshold sound level at which the notification signal is generated.

4. The supplemental alert generation device of claim 3, wherein the threshold sound level detector comprises a digital potentiometer that is adjustable by the controller to adjust said threshold sound level.

5. The supplemental alert generation device of claim 3, wherein the controller is programmed to implement a learn mode in which the controller adjusts the threshold sound level detector based on a detected alert signal generated by the detector/alert device.

6. The supplemental alert generation device of claim 1, wherein the threshold sound level detector comprises a piezoelectric sensor that converts sound into an electrical signal.

7. The supplemental alert generation device of claim 1, wherein the threshold sound level detector comprises a microphone.

8. The supplemental alert generation device of claim 1, further comprising a boosted Class D audio amplifier circuit coupled to an audio speaker, wherein the controller is programmed to cause an audible supplemental alert signal to be generated via the boosted Class D audio amplifier circuit and the audio speaker when an audible alert signal is detected.

9. The supplemental alert generation device of claim 1, wherein the supplemental alert signal is an audible square wave signal having a fundamental frequency between 400 and 700 hertz, and the supplemental alert generation device further includes a speaker enclosure assembly that outputs said audible square wave signal, said speaker enclosure assembly comprising an audio speaker mounted to an enclosure, and having a resonant frequency between 400 and 700 hertz.

10. The supplemental alert generation device of claim 1, in combination with the detector/alert device, wherein the supplemental alert generation device and the detector/alert device are mounted to a ceiling less than three feet from each other.

11. A method performed by a battery-powered supplemental alert generation device to monitor a detector/alert device that generates an audible alert signal, the method comprising:

comparing a sound level sensed by the supplemental alert generation device to a threshold to determine whether the sound level is sufficiently high to represent said audible alert signal;

in response to determining that the sound level is sufficiently high to represent the audible alert signal, initiating a signal analysis process to assess whether a sound detected by the supplemental alert generation device is the audible alert signal, wherein initiating the signal analysis process comprises waking a microcontroller from a sleep state, and initiating execution by the microcontroller of an analysis process in which the microcontroller assesses, at least, whether a received audio signal has a predefined pulse pattern; and

when the signal analysis process reveals a presence of the audible alert signal, generating and outputting a supplemental alert signal.

12. The method of claim 11, wherein the method further comprises determining whether a frequency of the received audio signal corresponds to a tone frequency used by detector/alert devices.

13. The method of claim 11, wherein the threshold is at least 70 dBA.

14. The method of claim 11, further comprising selecting said threshold by monitoring the audible alert signal in a learn mode.

15. The method of claim 11, wherein comparing the sound level to the threshold comprises passively converting sound into an electric signal via a piezoelectric sensor, and analyzing a level of the electrical signal.

16. The method of claim 15, wherein the piezoelectric sensor has a resonant frequency between 2900 hertz to 3400 hertz.

17. The method of claim 11, wherein the method is performed in its entirety via battery-powered circuitry, without any additional power source.

18. The method of claim 11, wherein the method is performed with the battery-powered supplemental alert generation device mounted to a ceiling less than three feet from the detector/alert device.

19. The method of claim 11, wherein generating and outputting a supplemental alert signal comprises synchronizing a pulse pattern of the supplemental alert signal in time with a pulse pattern of the audible alert signal.

20. The method of claim 11, wherein generating and outputting a supplemental alert signal comprises generating an audible supplemental alert signal using a boosted Class D amplifier coupled to an audio speaker.

21. The method of claim 20, wherein the audible supplemental alert signal is a square wave signal having a fundamental frequency between 400 and 700 hertz, and the method comprises outputting the audible supplemental alert signal via a speaker enclosure assembly having a resonant frequency between 400 and 700 hertz, said speaker enclosure assembly comprising said audio speaker mounted to an enclosure structure.

22. The method of claim 11, wherein the supplemental alert signal is an audible square wave signal having a fundamental frequency of about 520 hertz, and is generated using a speaker enclosure assembly having a resonant frequency of about 520 hertz.

23. The method of claim 11, further comprising, while operating in a learn mode:

outputting, via an audio speaker of the supplemental alert generation device, a voice message which instructs an operator to press a test button of the detector/alert device; and

selecting said threshold based on a detected level of the audible alert signal generated by the detector/alert device.