Circuit Integrity Detection System for Detecting The Integrity of A Sensing Wire in Electrically Heated Textiles

• US 20130293242A1
• Filed: 08/30/2012
• Published: 11/07/2013
• Est. Priority Date: 10/26/2011
• Status: Abandoned Application

• Current Assignee: Sunbeam Products, Inc. d/b/a Jarden Consumer Solutions (Newell Brands Inc.)
• Original Assignee: Sunbeam Products, Inc. d/b/a Jarden Consumer Solutions (Newell Brands Inc.)
• Inventors: Kohn, Gabriel, McCoy, William G., Horey, Leonard
• Application Number:
  US13/978,645
• Publication Number:
  US 20130293242A1
• Time in Patent Office: Days
• US Class Current: 324/511
• CPC Class Codes: G01K 13/00 Thermometers specially adapted for specific purposes
• CPC Class Codes: G01K 15/007 Testing
• CPC Class Codes: G01K 7/16 using resistive elements resistive elements per se H01C, H01L
• CPC Class Codes: G01N 1/00 Sampling; Preparing specimens for investigation
• CPC Class Codes: G01N 2201/00 Features of devices classified in G01N21/00
• CPC Class Codes: G01R 31/2829 Testing of circuits in sensor or actuator systems testing of apparatus for measuring electric or magnetic variables G01R35/00; testing of indicating or recording apparatus G01D; in airbag systems B60R21/0173; checking gas analysers G01N33/007; monitoring or fail-safe circuits for electromagnets H01F7/1844
• CPC Class Codes: G01R 31/52 Testing for short-circuits, leakage current or ground faults
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G01R 31/58 Testing of lines, cables or conductors testing of electric windings G01R31/72
• CPC Class Codes: H01L 2221/00 Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof covered by H01L21/00
• CPC Class Codes: H05B 1/0272 For heating of fabrics
• CPC Class Codes: H05B 2203/019 Heaters using heating elements having a negative temperature coefficient
• CPC Class Codes: H05B 2203/02 Heaters using heating elements having a positive temperature coefficient
• CPC Class Codes: H05B 3/342 heaters used in textiles

Abstract

A circuit integrity detection system for use in detecting the integrity of a sensing wire in a heating pad wherein the integrity of the sensing wire is determined by first driving one end of the sensing wire with a low voltage electrical test signal from a microcontroller, and then checking whether the test signal is present on the other end of the sensing wire, in order to distinguish the test signal from the standard AC line voltage present on the sensing wire, the electrical test signal is preferably of a different frequency than the standard 50-60 Hz AC line voltage. In one embodiment, the test signal frequency is approximately 30 kHz.

Claims

1. An electrically heated textile comprising:

a heating element in communication with an NTC material, wherein a first signal is generated through the heating element at a first frequency;

a sensing wire for detecting a hotspot created by the heating element;

a test signal generator electrically connected to the sensing wire for generating a second signal on a first end of the sensing wire, wherein the test signal has a second frequency; and

a signal detector for detecting the second signal on a second end of the sensing wire

2. The electrically heated textile as set forth in claim 1 further including:

a layer having a negative temperature coefficient (NTC) positioned between the heating element and the sensing wire.

3. The electrically heated textile as set forth in claim 2 where the NTC layer is wrapped around the heating element, and the sensing wire is wrapped around the NTC layer.

4. The electrically heated textile as set forth in claim 1, wherein said detecting occurs in the presence of the first signal.

5. The electrically heated textile as set forth in claim 4, wherein the first frequency is different from the second frequency.

6. The electrically heated textile as set forth in claim 5, wherein the first signal is an AC line voltage with the first frequency of approximately 50-60 Hz.

7. The electrically heated textile as set forth in claim 6, wherein the second frequency is at a frequency of approximately 30 kHz.

8. The electrically heated textile as set forth in claim 1, wherein said detecting occurs when the first signal is turned off.

9. The electrically heated textile as set forth in claim 8, wherein the first frequency is different from the second frequency.

10. The electrically heated textile as set forth in claim 8, wherein the first frequency is the same as the second frequency.

11. A circuit integrity detection system for use in detecting the integrity of a sensing wire in an electrically heated textile, the system comprising:

a sensing wire for detecting a hotspot created by a heating element of the electrically heated textile, wherein a first signal is generated through the heating element at a first frequency;

a test signal generator electrically connected to the sensing wire for generating a test signal at a second frequency on a first end of the sensing wire;

a signal detector for detecting the second frequency on a second end of the sensing wire.

12. The electrically heated textile as set forth in claim 11, wherein said detecting occurs in the presence of the first signal.

13. The electrically heated textile as set forth in claim 11, wherein said detecting occurs when the first signal is turned off.

14. A method for detecting the integrity of a sensing wire in an electrically heated textile having a heating element, the method comprising the steps of:

providing a sensing wire to monitor the electrically heated textile for hot spots;

applying a first signal having a first frequency to the heating element;

applying a second signal having a second frequency to a first end of the sensing wire; and

monitoring a second end of the sensing wire for a return signal corresponding to the second signal.

15. The method as set forth in claim 14 wherein the step of monitoring the second end of the sensing wire for a return signal corresponding to the second signal includes the steps of:

comparing the return signal to a threshold voltage;

counting transitions of the return signal above and below the threshold voltage;

determining whether the sensing wire is intact based on the number of counted transitions.

16. The method as set forth in claim 14, wherein monitoring of the second signal occurs in the presence of the first signal.

17. A The method as set forth in claim 14 further comprising the steps of:

disengaging power to the heating element of the electrically heated textile prior to applying the second signal to the first end of the sensing wire;

18. The method as set forth in claim 14 wherein the second frequency is different from the first frequency.

19. The method as set forth in claim 14 wherein the second frequency is the same as the first frequency.