Over heating detection and interrupter circuit

• US 8,325,454 B2
• Filed: 04/07/2009
• Issued: 12/04/2012
• Est. Priority Date: 04/07/2008
• Status: Active Grant

• Current Assignee: Technology Research Group LLC (Southwire Company)
• Original Assignee: Technology Research Corporation (Southwire Company)
• Inventors: Brugner, Frank S., Williams, Thomas S.
• Primary Examiner(s): Nguyen, Danny
• Application Number:
  US12/384,624
• Publication Number:
  US 20090251832A1
• Time in Patent Office: 1,337 Days
• Field of Search: 361/106, 361/103, 361/25, 361/27, 361/105, 361/670, 361/42
• US Class Current: 361/103
• CPC Class Codes: H01R 13/6683 with built-in sensor
• CPC Class Codes: H01R 2103/00 Two poles
• CPC Class Codes: H01R 24/28 Coupling parts carrying pins, blades or analogous contacts and secured only to wire or cable
• CPC Class Codes: H02H 5/042 using temperature dependent resistors

Abstract

An over heating detection circuit and an interrupter circuit are disclosed for interrupting electrical power from a power source receptacle to a load upon the detection of an over heating condition of an electrical plug. A heat sensitive device monitors the temperature of the electrical plug. The over heating detection circuit is connected to the heat sensitive device for detecting an over heated condition in the electrical plug. The interruption circuit includes a disconnect switch connected to the over heating detection circuit for disconnecting electrical power upon the detection of the over heated condition in the electrical plug.

Claims

1. An over heating detection and interrupter circuit for detecting an over heating condition of an electrical plug having a first and a second electrical blades inserted into slots of a power source receptacle, comprising:

a first and a second thermistor mounted directly to the first and second electrical blades for monitoring the temperature of the electrical plug;

an over heating detection circuit connected to said first and second thermistors for detecting an over heated condition in the electrical plug; and

an interruption circuit having a disconnect switch connected to said over heating detection circuit for disconnecting electrical power upon the detection of an over heated condition in the electrical plug.

2. An over heating detection and interrupter circuit as set forth in claim 1, wherein each of said first and second thermistors provides an electrical output upon detecting said over heated condition in the electrical plug.

3. An over heating detection and interrupter circuit as set forth in claim 1, including a device switch connected in series with said first and second thermistors for connecting and disconnecting powering to said electrical heat sensitive device.

4. An over heating detection and interrupter circuit as set forth in claim 1, wherein said disconnect switch comprises a disconnect switch input circuit connected to the power source and a disconnect switch output circuit connected to the load;

and

said first and second thermistors being connected to said disconnect switch input circuit for powering said electrical heat sensitive device.

5. An over heating detection and interrupter circuit as set forth in claim 1, wherein said disconnect switch comprises a disconnect switch input circuit connected to the power source and a disconnect switch output circuit connected to the load;

and

said first and second thermistors being connected to said disconnect switch output circuit for powering said electrical heat sensitive device.

6. An over heating detection and interrupter circuit as set forth in claim 1, wherein said disconnect switch comprises a disconnect switch input circuit connected to the power source and a disconnect switch output circuit connected to the load;

said first and second thermistors being connected to said disconnect switch input circuit for powering said electrical heat sensitive device; and

a heat sensitive device switch interposed between said first and second thermistors and said disconnect switch input circuit for connecting and disconnecting power to said electrical heat sensitive device.

8. An over heating detection and interrupter circuit as set forth in claim 1, including an optocoupler and heat sensitive device switch located on opposed sides of said first and second thermistors.

7. An over heating detection and interrupter circuit for detecting an over heating condition of an electrical plug having a first and a second electrical blade inserted into slots of a power source receptacle, comprising:

a first and a second thermistor mounted directly to the first and second electrical blades for monitoring the temperature of the electrical plug;

a first and a second optocoupler interconnecting said first and second thermistor to an over heating detection circuit for detecting an over heated condition in the electrical plug; and

an interruption circuit having a disconnect switch connected to said over heating detection circuit for disconnecting electrical power upon the detection of an over heated condition in the electrical plug.

9. An over heating detection and interrupter circuit for interrupting electrical power from a power source receptacle to a load upon the detection of an over heating condition of an electrical plug inserted into a first and a second slot of the power source receptacle, comprising:

an electrical plug housing supporting a first and a second electrical blade for insertion within the first and second slots of the power source receptacle;

a first and a second thermistor mounted directly to said first and second electrical blades for monitoring the temperature of each of said first and second electrical blades;

an over heating detection circuit connected to said first and second thermistors for providing an over heating detection circuit electrical output upon the detection of an over heated condition in one of said first and second electrical blades; and

an interruption circuit having a disconnect switch connected for receiving said over heating detection circuit output for disconnecting electrical power to the load upon said over heating detection circuit detecting an over heated condition in one of said first and second electrical blades.

10. An over heating detection and interrupter circuit as set forth in claim 9, wherein said disconnect switch is located internal to said electrical plug housing.

11. An over heating detection and interrupter circuit as set forth in claim 9, wherein said disconnect switch is located external to said electrical plug housing.

12. An over heating detection and interrupter circuit as set forth in claim 9, wherein said disconnect switch is located as an integral part of the powered load assembly.

13. An over heating detection and interrupter circuit as set forth in claim 9, wherein the communication from the plug to the disconnect switch is either via the power supply cord or via wireless communication.

14. An over heating detection and interrupter circuit as set forth in claim 9, wherein each said first and second thermistors has plural power terminals;

one of said plural power terminals of said first electrical heat sensitive device being connected to said first electrical blade; and

one of said plural power terminals of said second electrical heat sensitive device being connected to said second electrical blade.

15. An over heating detection and interrupter circuit for detecting an over heating condition of an electrical plug having an electrical blade inserted into a slot of a power source receptacle, comprising:

an electrical heat sensitive device mounted directly to the first and second electrical blades for monitoring the temperature of the electrical plug;

an over heating detection circuit connected to said electrical heat sensitive device for detecting an over heated condition in the electrical plug;

an optocoupler interposed between said electrical heat sensitive device and said over heating detection circuit for electrically isolating said electrical heat sensitive device from said over heating detection circuit; and

an interruption circuit having a disconnect switch connected to said over heating detection circuit for disconnecting electrical power upon the detection of an over heated condition in the electrical plug.