Over heating detection and interrupter circuit

• US 20090251832A1
• Filed: 04/07/2009
• Published: 10/08/2009
• 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.
• Granted Patent: US 8,325,454 B2
• Time in Patent Office: Days
• US Class Current: 361/42
• 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 circuit for detecting an over heating condition of an electrical plug inserted into a power source receptacle, comprising:

a heat sensitive device for monitoring the temperature of the electrical plug;

an over heating detection circuit connected to said heat sensitive device 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 the electrical plug comprises an electrical plug housing supporting a first and a second electrical blade for insertion within a first and a second slot of the power source receptacle;

and

a heat sensitive device comprising a first and second heat sensitive device located in thermal contact with said first and second electrical blades.

3. An over heating detection and interrupter circuit as set forth in claim 1, wherein the electrical plug comprises an electrical plug housing supporting a first and a second electrical blade for insertion within a first and a second slot of the power source receptacle;

and

a heat sensitive device comprising a first and second heat sensitive device thermally mounted to said first and second electrical blades for detecting said over heated condition in the electrical plug.

4. An over heating detection and interrupter circuit as set forth in claim 1, wherein said heat sensitive device comprises a heat sensitive device.

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

and

said heat sensitive device being connected to said disconnect switch input circuit for powering said heat sensitive device.

7. 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 heat sensitive device being connected to said disconnect switch output circuit for powering said heat sensitive device.

8. 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 heat sensitive device being connected to said disconnect switch input circuit for powering said heat sensitive device; and

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

9. An over heating detection and interrupter circuit as set forth in claim 1, including an optocoupler connecting said heat sensitive device switch to said over heating detection circuit.

10. 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 heat sensitive device.

11. 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 heat sensitive device located in thermal contact with 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 heat sensitive devices for providing an over heating detection circuit 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.

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

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

14. An over heating detection and interrupter circuit as set forth in claim 11, wherein said disconnect switch is located as an integral part of the powered load assembly.

15. An over heating detection and interrupter circuit as set forth in claim 11, wherein the communication from the plug to the disconnect switch is either via the power supply cord or via wireless communication.

16. An over heating detection and interrupter circuit as set forth in claim 11, wherein each said first and second heat sensitive devices has plural power terminals;

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

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

17. An electrical plug enclosing an over heating detection circuit for connection to an interruption circuit for interrupting electrical power from a power source receptacle to a load upon the detection of an over heating condition of the electrical plug inserted into the power source receptacle, comprising:

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

a first and a second heat sensitive device located in thermal contact with said first and second electrical blades for sensing the temperature of each of said first and second electrical blades; and

a plurality of conductors connecting said first and second heat sensitive devices to the interruption circuit for interrupting electrical power from the power source receptacle to the load upon said over heating detection circuit detecting an over heated condition in one of said first and second electrical blades.

18. In a ground fault circuit interrupter for disconnecting electrical power from a power source receptacle to a load upon the detection of a ground fault condition occurring between an electrical plug inserted into the power source receptacle and the load, the improvement comprising:

an over heating detection circuit including a heat sensitive device located in the electrical plug for monitoring the temperature of the electrical plug input terminals; and

a conductor interconnecting said over heating detection circuit to the ground fault circuit interrupter for disconnecting electrical power upon said over heating detection circuit detecting an over heated condition in the electrical plug.

19. In a leakage current detection and interruption circuit for disconnecting electrical power from a power source receptacle to a load upon the detection of a leakage current condition occurring between an electrical plug inserted into the power source receptacle and the load,

the improvement comprising:

an over heating detection circuit including a heat sensitive device located in the electrical plug for monitoring the temperature of the electrical plug input terminals; and

a conductor interconnecting said over heating detection circuit to the leakage current detection and interruption circuit for disconnecting electrical power upon said over heating detection circuit detecting an over heated condition in the electrical plug.

20. In a leakage current detection and interruption circuit as set forth in claim 19, wherein the leakage current of the power cord shield or the over heating detection circuit will provide for opening of the disconnect switch in the device.

21. In a leakage current detection and interruption circuit as set forth in claim 19, wherein the an electrically conductive shield in the power supply cord may have a plurality of configurations surrounding one or more power supply wires within the power supply cord.

22. An electrical outlet adapter for providing over heating protection for a conventional electrical plug electrically connected to a power source receptacle, comprising

an outlet adapter housing having electrical lugs extending from said outlet adapter housing for insertion into the power source receptacle;

said outlet adapter housing having an electrical socket defined within said outlet adapter housing for receiving the conventional electrical plug;

an interruption circuit having a disconnect switch located internal to said outlet adapter housing interconnecting said electrical lugs to said electrical socket of said outlet adapter housing;

an electrical lug heat sensitive device located in said outlet adapter housing for monitoring the temperature of said electrical lugs of said outlet adapter housing;

an electrical socket heat sensitive device located in said outlet adapter housing for monitoring the temperature of said electrical socket of said outlet adapter housing;

an over heating detection circuit connected to said electrical lug and said electrical socket heat sensitive devices for detecting an over heated condition in said electrical lugs and said electrical socket of said outlet adapter housing; and

said over heating detection circuit connected to said interruption circuit for opening said disconnect switch upon the detection of an over heated condition in said electrical lugs and said electrical socket of said outlet adapter housing.

23. An electrical outlet adapter according to claim 22, wherein said adapter also functions as a ground fault protection device.

24. An electrical outlet adapter according to claim 22, wherein the disconnect switch for over temperature protection is also the disconnect switch for ground fault protection.

25. An electrical outlet adapter according to claim 22, wherein the disconnect switch for over current protection is also the disconnect switch for leakage current protection.

26. A fault detection and interruption circuit for disconnecting electrical power from a power source receptacle to a load upon the detection of a leakage fault current condition occurring between an electrical plug inserted into the power source receptacle, the power cord and the load,

the improvement comprising:

an over heating detection circuit including a heat sensitive device located in the electrical plug for monitoring the temperature of the electrical plug input terminals; and

a conductor interconnecting said over heating detection circuit to the fault detection and interruption circuit of the leakage current device for disconnecting electrical power upon said over heating detection circuit detecting an over heated condition in the electrical plug.