Outdoor alerting device for smoke alarms

• US 5,745,040 A
• Filed: 10/23/1996
• Issued: 04/28/1998
• Est. Priority Date: 10/23/1996
• Status: Expired due to Fees

• Current Assignee: Lisa M. Loughridge
• Original Assignee: Lisa M. Loughridge
• Inventors: Loughridge, Lisa M.
• Primary Examiner(s): Hofsass, Jeffey
• Assistant Examiner(s): Wu, Daniel J.
• Application Number:
  US08/740,023
• Time in Patent Office: 552 Days
• Field of Search: 340/539, 340/577-579, 340/584, 340/628-630, 340/691-693, 367/197-199, 381/56-58
• US Class Current: 340/628
• 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
• CPC Class Codes: G08B 17/00 Fire alarms; Alarms responsive to explosion
• CPC Class Codes: G08B 7/064 indicating houses needing emergency help, e.g. with a flashing light or sound

Abstract

An outdoor alerting device for smoke alarms including an alarm detecting and alerting device drive unit and an exterior alerting device including a loudspeaker installed within a housing and a light display unit attached to the housing and having a light bulb. The alarm detecting and alerting device drive unit includes an alarm detection circuit including a microphone having a microphone output in electrical connection with an amplifier circuit for converting the audible alarm into an amplified electrical microphone signal. The amplified electrical microphone signal is then passed through a band pass filter that is tuned to the main audible output frequency of the audible alarm of the smoke detector to produce a filtered microphone signal. The filtered microphone signal is the passed through a rectifier circuit to convert the filtered microphone signal into a DC microphone signal. The DC microphone signal is then output to the signal input of a comparator. The reference input of the comparator is supplied with a predetermined reference voltage such as through a voltage divider circuit. The output of the comparator is used to trigger the exterior alerting device after being passed through a delay network.

Claims

1. An outdoor alerting device for smoke alarms comprising:

an alarm detecting and alerting device drive unit having a alarm detecting circuit for detecting an audible alarm from a smoke detector; and

an exterior alerting device including a housing having an audible noise generating mechanism installed within a compartment formed within said housing, and a visual attraction mechanism in connection with said housing, said audible noise generating mechanism and said visual attraction mechanism being responsive to a signal from said alarm defecting and alerting device drive unit;

said alarm detecting circuit including;

a microphone,

an amplifier circuit,

a band pass filter,

a rectifier circuit,

a comparator including a reference voltage generating network,

a first retriggerable monostable multi-vibrator, and

a first OR logic gate;

said microphone having a microphone output in electrical connection with an amplifier input of said amplifier circuit;

said amplifier circuit having an amplifier output in electrical connection with a filter input of said band pass filter;

said band pass filter having a filter output in electrical connection with a rectifier input of said rectifier circuit;

said rectifier circuit having a rectifier output in electrical connection with a signal input of said comparator;

said reference voltage generating network having a reference voltage output in electrical connection with a reference voltage input of said comparator;

said comparator having a comparator output in electrical connection with a first trigger input of said first retriggerable monostable multi-vibrator and a first OR gate input of said first OR logic gate; and

said first retriggerable monostable multi-vibrator having a first multi-vibrator output in electrical connection with a second OR gate input of said first OR logic gate.

2. The outdoor alerting device for smoke alarms of claim 1 wherein:

said alarm detecting circuit further includes;

a first non-retriggerable monostable multi-vibrator;

a delay network;

an AND logic gate; and

a second non-retriggerable, resettable, monostable multi-vibrator; and

wherein;

an OR gate output of said first OR logic gate is electrically connected to a delay input of said delay network and a second trigger input of said first non-retriggerable, monostable multi-vibrator;

a delay output of said delay network is electrically connected to a first AND gate input of said first AND logic gate; and

a second multi-vibrator output of said non-retriggerable, monostable multi-vibrator is electrically connected to a second AND gate input of said AND logic gate.

3. The outdoor alerting device for smoke alarms of claim 2 wherein:

said AND logic gate has an AND gate output in electrical connection with a third trigger input of a second non-retriggerable, resettable, monostable multi-vibrator; and

said second non-retriggerable, resettable, monostable multi-vibrator has a third multi-vibrator output in electrical connection with a power relay.

4. The outdoor alerting device for smoke alarms of claim 3 wherein:

said second non-retriggerable, resettable, monostable multi-vibrator has a reset input; and

said alarm detecting circuit further includes a momentary contact switch in electrical connection with said reset input.

5. The outdoor alerting device for smoke alarms of claim 1 wherein:

a pass band of said band pass filter is selected to be the bandwidth at which the greatest audible power is output from a smoke detector speaker.

6. The outdoor alerting device for smoke alarms of claim 5, wherein:

said alarm detecting circuit further includes;

a first non-retriggerable monostable multi-vibrator;

a delay network;

an AND logic gate; and

a second non-retriggerable, resettable, monostable multi-vibrator; and

wherein;

an OR gate output of said first OR logic gate is electrically connected to a delay input of said delay network and a second trigger input of said first non-retriggerable, monostable multi-vibrator;

a delay output of said delay network is electrically connected to a first AND gate input of said first AND logic gate; and

a second multi-vibrator output of said non-retriggerable, monostable multi-vibrator is electrically connected to a second AND gate input of said AND logic gate.

7. The outdoor alerting device for smoke alarms of claim 6 wherein:

said AND logic gate has an AND gate output in electrical connection with a third trigger input of a second non-retriggerable, resettable, monostable multi-vibrator; and

said second non-retriggerable, resettable, monostable multi-vibrator has a third multi-vibrator output in electrical connection with a power relay.

8. The outdoor alerting device for smoke alarms of claim 7 wherein:

said second non-retriggerable, resettable, monostable multi-vibrator has a reset input; and

said alarm detecting circuit further includes a momentary contact switch in electrical connection with said reset input.