MODULATED AUDIO ANNUNCIATOR PROVIDING STAND-ALONE HIGH VOLTAGE COMPATIBILITY

• US 20150221204A1
• Filed: 08/15/2013
• Published: 08/06/2015
• Est. Priority Date: 08/16/2012
• Status: Active Grant

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Barrena, Juan, Larson, Eric K., Tucker, Andrew W., Prunty, Jeffrey L.
• Granted Patent: US 9,443,412 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: D06F 2103/38 Time, e.g. duration
• CPC Class Codes: D06F 2103/40 Opening or locking status of doors
• CPC Class Codes: D06F 2103/44 Current or voltage
• CPC Class Codes: D06F 2105/60 Audible signals
• CPC Class Codes: D06F 34/08 Control circuits or arrangements thereof
• CPC Class Codes: D06F 34/28 Arrangements for program selection, e.g. control panels therefor; Arrangements for indicating program parameters, e.g. the selected program or its progress
• CPC Class Codes: F25D 29/00 Arrangement or mounting of control or safety devices
• CPC Class Codes: F25D 29/008 Alarm devices
• CPC Class Codes: G08B 21/18 Status alarms G08B21/02 takes precedence
• CPC Class Codes: G08B 3/10 using electric transmission; using electromagnetic transmission

Abstract

An integrated line voltage converter and microprocessor-controlled tone generator allow advanced alarm features to be implemented in standard appliances as powered by a high-voltage line power. An integrated switch may also be used to allow the addition of alarm features to standard appliances as a drop-in replacement for door switches.

Claims

1. An appliance alarm for an appliance of a type providing a line power source of line-voltage alternating current, the appliance alarm comprising:

a housing providing a mounting element for attaching the appliance alarm to the appliance;

a conductor system providing an electrical connection between the appliance alarm and line power from the appliance; and

a circuit card retained at least in part within the housing and including;

(a) a power converter converting line-voltage alternating current to logic level direct-current;

(b) a audio annunciator; and

(c) a controller circuit receiving the logic level direct-current and providing an output line communicating with the audio annunciator to provide a modulated signal to the audio annunciator to produce a distinctive modulated audio tone.

2. The appliance alarm of claim 1 further including an electrical switch having a switch operator extending from the housing to move between an open and closed state, the switch operator communicating with electrical contacts providing an electrical signal to the controller circuit.

3. The appliance alarm of claim 2 wherein the electrical switch communicates between the logic level direct-current from the power converter and an input from the controller circuit.

4. The appliance alarm of claim 2 wherein the electrical switch communicates between the conductor system providing electrical connection to line power and the power converter.

5. The appliance alarm of claim 1 wherein the power converter provides a current flow through connectors connecting the power converter to line power of at least 100 milliamps and a voltage drop of less than 50 volts so that when the electrical switch is closed, a standard line voltage incandescent bulb in series with the power converter is substantially fully illuminated when the switch is closed and turned off when the switch is open.

6. The appliance alarm of claim 2 wherein the switch operator moves between the open and closed states in a plane parallel to a plane of the circuit card.

7. The appliance alarm of claim 2 wherein the switch is supported for motion by the housing and printed circuit board and include switch contacts electrically supported by the printed circuit board.

8. The appliance alarm of claim 1 wherein the audio annunciator is a metallic disk including a coating of piezoelectric material, the metallic disk supported by and electrically communicating through its edges with the circuit card.

9. The appliance alarm of claim 1 wherein the housing provides a resonator chamber positioned adjacent to the audio annunciator.

10. The appliance alarm of claim 1 wherein the power converter employs multiple series-connected discrete resistors to provide a reduction in line voltage, the discrete resistors spaced over a surface of the circuit card.

11. The appliance alarm of claim 1 wherein the conductor system further includes a low voltage electrical connector providing a logic level direct current signal to the controller circuit and wherein the controller circuit responds to the logic level direct-current signal by changing a modulated signal to provide a second distinctive modulated audio tone.

12. The appliance alarm of claim 1 wherein the controller circuit provides a first modulated signal for a first period of time to start an internal timer upon a starting of the first modulated signal and to provide a second modulated signal for a second period of time upon expiration of the timer.

13. The appliance alarm of claim 1 wherein the housing includes an electrical connector shell allowing a mating connector to fit within the electrical connector shell and connect with connector pins attached to the circuit card.

14. In a refrigerator having a cabinet with at least one door opening and closing with respect to a refrigerated volume for access thereto, an appliance alarm comprising:

a housing providing a mounting element for attaching the appliance alarm to the appliance;

a conductor system providing an electrical connection between the appliance alarm and line power from the appliance; and

a circuit card retained within the housing and including;

(a) a power converter converting line-voltage alternating current to logic level direct-current;

(b) a audio annunciator; and

(c) a microcontroller receiving the logic level direct-current and providing an output line communicating with the audio annunciator and executing a program stored in non-transient memory to provide a modulated signal to the audio annunciator to produce a distinctive modulated audio tone.