System and method for identifying the location of thermal events detected by temperature sensing tape

Abstract

A system and method are provided for identifying the location of a thermal event detected by a temperature sensing tape. [Solution] In some embodiments, the temperature sensing tape may have a resistor ladder with parallel resistors between multiple temperature sensing elements to generate a voltage divider circuit, and a unique analog output voltage may correspond to a different of the multiple temperature sensing elements that are activated. In some embodiments, pulses injected into the temperature sensing tape and thereby reflected may be used to detect the distance to the location where the trigger event was detected.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 713,851, filed October 30, 2024, entitled "SYSTEMS AND METHODS FOR IDENTIFYING A LOCATION OF A THERMAL EVENT DETECTED BY A TEMPERATURE SENSING TAPE", under 35 U.S.C. § 119, and the entire disclosure of such application is incorporated herein by reference in its entirety.

[0002] This disclosure generally relates to temperature sensing devices. More specifically, this disclosure relates to systems and methods for identifying the location of a thermal event detected by a temperature sensing tape.

Background Art

[0003] Electrical systems and devices such as batteries and semiconductors can be damaged by such conditions, for example, if the persistence of a high - temperature state is tolerated. Thus, electrical systems and devices are generally equipped with temperature sensing devices that can be used to measure temperature changes at discrete locations within or on the electrical system or device. For example, if the measured temperature exceeds a predetermined threshold, the associated electrical system or device to be protected is automatically shut off until such condition is alleviated or corrected, thereby preventing or reducing any damage to the associated electrical system or device.

[0004] Some known temperature sensing devices include a temperature sensing tape having temperature sensing elements at discrete locations on or inside it. These devices output a digital signal (e.g., high or low) to identify a thermal event, but do not identify the location of the thermal event. Therefore, if the temperature sensing tape is attached to an electrical system such as a battery pack, the output signal only identifies that the battery pack is experiencing a thermal event, but does not identify which cell within the battery pack is experiencing the event.

[0005] This disclosure may be useful in relation to these and other considerations. [Overview of the project]

[0006] This summary is provided to introduce, in a simplified form, the selection of concepts that will be further explained below in the detailed description. This summary is not intended to identify any important or essential features of the claimed subject matter, nor is it intended to assist in determining the scope of the claimed subject matter.

[0007] In some embodiments, the temperature sensing tape may comprise an insulating support structure, a plurality of temperature sensing elements electrically connected in series and positioned on the insulating support structure, and resistors connected in parallel between each of the plurality of temperature sensing elements and positioned on the insulating support structure. A trigger event detected by one of the plurality of temperature sensing elements may cause a change in the impedance of the one of the plurality of temperature sensing elements and cause an open circuit in the plurality of temperature sensing elements downstream of the one of the plurality of temperature sensing elements.

[0008] In some embodiments, the temperature sensing tape may comprise a conductive circuit having a plurality of temperature sensing elements, each of the resistors connected in parallel between each of the plurality of temperature sensing elements, and a flexible conductor disposed on the insulating support structure between them. The output voltage of the conductive circuit may indicate which of the multiple temperature sensing elements detected the trigger event.

[0009] In some embodiments, the temperature sensing tape may be provided with a pull-up resistor at one end of the conductive circuit, and the output voltage may be measured at the pull-up resistor.

[0010] In some embodiments, the temperature sensing tape may include an amplification circuit electrically connected to the conductive circuit.

[0011] In some embodiments, the temperature sensing tape may comprise a conductive circuit having a plurality of temperature sensing elements, each of the resistors connected in parallel between each of the plurality of temperature sensing elements, and a flexible conductor disposed on the insulating support structure between them. A first output voltage at a first end of the conductive circuit may identify a first temperature sensing element among the plurality of temperature sensing elements that detected the trigger event, and a second output voltage at a second end of the conductive circuit may identify a second temperature sensing element among the plurality of temperature sensing elements that detected the trigger event.

[0012] In some embodiments, the plurality of temperature sensing elements may include polymeric positive temperature coefficient (PPTC) sensors or printed temperature indicator (PTI) sensors, and each of the resistors connected in parallel between each of the plurality of temperature sensing elements may be made of a high-resistance, low-temperature-coefficient material.

[0013] In some embodiments, the temperature sensing tape may comprise an insulating support structure, a plurality of temperature sensing elements electrically connected in series and arranged on the insulating support structure, and a flexible conductor arranged on the insulating support structure and arranged in series with the plurality of temperature sensing elements to form a conductive circuit. A trigger event detected by one of the plurality of temperature sensing elements may cause a change in the impedance of that one of the plurality of temperature sensing elements, and the incident pulse signal injected into the conductive circuit may be reflected as a reflected pulse signal by that one of the plurality of temperature sensing elements.

[0014] In some embodiments, the time difference between the incident pulse signal and the reflected pulse signal may indicate which of the plurality of temperature sensing elements detected the trigger event.

[0015] In some embodiments, the conductive circuit may have a uniform impedance in the absence of the trigger event.

[0016] In some embodiments, the flexible conductor positioned between two of the plurality of temperature sensing elements may be formed in a corrugated shape, thereby increasing the length of the flexible conductor and the electrical distance over which the incident pulse signal and the reflected pulse signal are transmitted, without increasing the physical distance between the two of the plurality of temperature sensing elements.

[0017] In some embodiments, the speed of the incident pulse signal and the reflected pulse signal can be reduced by increasing the inductance and capacitance of the temperature sensing tape.

[0018] In some embodiments, the method may comprise the steps of: one of a plurality of temperature sensing elements of a conductive circuit, electrically connected in series with a flexible conductor and arranged on an insulating support structure of a temperature sensing tape, detects a trigger event; in response to the detection of the trigger event, the impedance of the one of the plurality of temperature sensing elements is changed to create an open circuit in the plurality of temperature sensing elements downstream of the one of the plurality of temperature sensing elements; and outputting an output signal from the conductive circuit. The output signal may indicate which of the plurality of temperature sensing elements detected the trigger event.

[0019] In some embodiments, each resistor may be connected in parallel between each of the plurality of temperature sensing elements, and the output signal may include an output voltage.

[0020] In some embodiments, the method may further include the steps of measuring the output voltage in a pull-up resistor located at one end of the conductive circuit, and identifying in a look-up table relating to the temperature sensing tape which of the plurality of temperature sensing elements corresponds to the output voltage.

[0021] In some embodiments, the method may include a step of amplifying the output voltage by an amplification circuit electrically connected to the conductive circuit.

[0022] In some embodiments, the method may include the steps of: measuring the output voltage at a first end of the conductive circuit to identify a first temperature sensing element among the plurality of temperature sensing elements that detected the trigger event; and measuring the output voltage at a second end of the conductive circuit to identify a second temperature sensing element among the plurality of temperature sensing elements that detected the trigger event.

[0023] In some embodiments, the output signal may include a reflected pulse signal that is injected into the conductive circuit and reflected by the one of the plurality of temperature sensing elements.

[0024] In some embodiments, the method may include measuring a time difference between the incident pulse signal and the reflected pulse signal, and identifying which of the plurality of temperature sensing elements corresponds to the time difference for the temperature sensing tape.

[0025] In some embodiments, the method may include matching the impedance of the flexible conductor to the impedance of the plurality of temperature sensing elements to generate a uniform impedance in the conductive circuit in the absence of the trigger event.

[0026] In some embodiments, the flexible conductor disposed between two of the plurality of temperature sensing elements may be formed in a wavy shape, increasing the length of the flexible conductor and the electrical distance traveled by the incident pulse signal and the reflected pulse signal without increasing the physical distance between the two of the plurality of temperature sensing elements.

[0027] Other technical features may be readily apparent to those skilled in the art from the following figures, description, and claims.

Brief Description of the Drawings

[0028] To facilitate easy identification of any particular element or operation, the top one or more digits in the reference numbers refer to the figure number in which the element is first introduced.

[0029] [Figure 1] A block diagram showing a thermal protection system according to the disclosed embodiments.

[0030] [Figure 2] A top view showing a temperature sensing tape according to the disclosed embodiments.

[0031] [Figure 3] This is a circuit diagram showing the conductive circuit of a temperature sensing tape according to the disclosed embodiment.

[0032] [Figure 4A] This graph shows a comparison between the output voltage and the activated temperature sensing element in a temperature sensing tape having a resistor with a tolerance of 0% according to the disclosed embodiment.

[0033] [Figure 4B] This graph shows a comparison between the output voltage and the activated temperature sensing element in a temperature sensing tape having a resistor with a tolerance of 1% according to the disclosed embodiment.

[0034] [Figure 4C] This graph shows a comparison between the output voltage and the activated temperature sensing element in a temperature sensing tape having a resistor with a tolerance of 5% according to the disclosed embodiment.

[0035] [Figure 5A] This is a circuit diagram showing the conductive circuit of the temperature sensing tape during the first scan in a dual scan according to the disclosed embodiment.

[0036] [Figure 5B] This is a circuit diagram showing the conductive circuit of the temperature sensing tape during the second scan in a dual scan according to the disclosed embodiment.

[0037] [Figure 6] This graph shows a comparison between the output voltage and the activated temperature sensing element during double scanning of a temperature sensing tape according to the disclosed embodiment.

[0038] [Figure 7] This is a block diagram showing a thermal protection system according to a disclosed embodiment.

[0039] [Figure 8]This graph shows the incident pulse signal and the reflected pulse signal from the activated temperature sensing element in the temperature sensing tape according to the disclosed embodiment.

[0040] [Figure 9] This figure shows a temperature sensing tape according to the disclosed embodiment. [Modes for carrying out the invention]

[0041] Next, exemplary embodiments of a system and method for identifying the location of a thermal event detected by a temperature sensing tape according to the present disclosure will be described in more detail below with reference to the accompanying drawings. However, such systems and methods can be embodied in many different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so that the present disclosure can convey specific exemplary aspects to those skilled in the art.

[0042] As used herein, the term "temperature sensing tape" or similar may refer to a structure having one temperature sensing element or an array of multiple temperature sensing elements, which may be electrically arranged in series with a conductor, which may be incorporated into a flexible tape material, cloth material, or woven structure, or it may be a self-supporting conductor such as a wire. In some embodiments, the temperature sensing tape can be used for distributed temperature sensing by attaching the temperature sensing tape to a protected element at a location where the temperature is to be measured. For example, the temperature sensing tape may be attached to a protected element to provide thermal contact between the temperature sensing element and the protected element at the location where at least one of the temperature sensing elements is present.

[0043] Embodiments disclosed herein include systems and methods for identifying the location of a thermal event detected by a temperature sensing tape. For example, the temperature sensing tape may comprise a plurality of temperature sensing elements of a conductive circuit, electrically connected in series with a flexible conductor and arranged on an insulating support structure of the temperature sensing tape. One of the plurality of temperature sensing elements may detect a trigger event, such as a thermal event, and in response, a change in its impedance may occur, thereby creating an open circuit in a plurality of temperature sensing elements downstream of that one. Such a change in impedance may include an increase from low to high or a decrease from high to low. In particular, such a change in impedance in one of the plurality of temperature sensing elements that detected the trigger event may isolate a plurality of temperature sensing elements downstream of that one. The conductive circuit may then output an output signal that indicates which of the plurality of temperature sensing elements detected the trigger event.

[0044] The systems and methods disclosed herein can be implemented in at least two different embodiments. First, the temperature sensing tape may comprise a resistor ladder having parallel resistors between a plurality of temperature sensing elements to generate a voltage divider circuit. Second, the distance to the location where a trigger event is detected can be detected using pulses injected into and reflected by the temperature sensing tape and the principle of time-domain reflectometry (TDR).

[0045] First, we will discuss the details of the resistor ladder embodiment. Each resistor may be connected in parallel between each of the multiple temperature sensing elements. In these embodiments, the signal output by the conductive circuit may include the output voltage. That is, the signal output by the conductive circuit may be an analog signal, and as a result, different analog signals may correspond to different of the multiple temperature sensing elements that were activated by the detection of a trigger event.

[0046] In some embodiments, the output voltage may be measured in a pull-up resistor located at one end of the conductive circuit, and which of a plurality of temperature sensing elements corresponds to the output voltage can be identified in a lookup table relating to the temperature sensing tape, thereby identifying which of the plurality of temperature sensing elements detected a trigger event. In addition, or alternatively, in some embodiments, the output voltage may be amplified by an amplification circuit electrically connected to the conductive circuit.

[0047] In some embodiments, a double scan can be performed to identify more than one of the multiple temperature sensing elements that detected the trigger event, and thus identify the boundary of the heated area. For example, the output voltage at a first end of a conductive circuit can be measured to identify a first temperature sensing element among the multiple temperature sensing elements that detected the trigger event, and the output voltage at a second end of the conductive circuit can be measured to identify a second temperature sensing element among the multiple temperature sensing elements that detected the trigger event.

[0048] Secondly, we discuss the details of the pulses and TDRs injected into and reflected by the temperature sensing tape. The signal output by the conductive circuit may include a reflected pulse signal, which is a reflection of the incident pulse signal injected into the conductive circuit and reflected by one of several temperature sensing elements that detected the trigger event. In these embodiments, the time difference between the incident pulse signal and the reflected pulse signal may be measured, and this time difference may indicate which of the several temperature sensing elements detected the trigger event. In this regard, different time differences may correspond to different of the several temperature sensing elements that were activated by the detection of the trigger event. For example, in some embodiments, the time difference can be identified in a lookup table relating to the temperature sensing tape to identify which of the several temperature sensing elements detected the trigger event. In addition, or alternatively, in some embodiments, the distance to one of the several temperature sensing elements that detected the trigger event can be identified by multiplying the propagation speed of the incident pulse signal by the time difference and dividing the product by 2.

[0049] In some embodiments, the conductive circuit may have a uniform impedance to facilitate the reflection of the reflected pulse signal by one of a plurality of temperature sensing elements that detected the trigger event. In particular, when there is no trigger event (i.e., in the absence of a trigger event), the impedance of a flexible conductor can be matched to the impedance of one of the plurality of temperature sensing elements to generate a uniform impedance in the conductive circuit. In some embodiments, to achieve such matching, a flexible conductor placed between two of the plurality of temperature sensing elements may be formed in a corrugated shape, thereby increasing the length of the flexible conductor and the electrical distance over which the incident and reflected pulse signals travel without increasing the physical distance between the two of the plurality of temperature sensing elements.

[0050] Figure 1 is a block diagram showing a thermal protection system 100 according to a disclosed embodiment. As shown, the thermal protection system 100 may include a protected element 102 that can be connected to a load 108 to supply power to it. In the embodiment shown in Figure 2, the protected element 102 may include, or may be, a battery that may include a plurality of cells 104a, 104b, 104c, 104d that can be electrically connected in series. For example, the protected element 102 may include, or may be, a lithium-ion battery, a lithium polymer battery, a Ni-MH rechargeable battery, and the like. However, the embodiments disclosed herein are not limited in this respect and may include any protected element that will be understood by those skilled in the art, including any power source or electrical device that would benefit from protection against high temperatures. For example, in some embodiments, the protected element 102 may include, or could be, a printed circuit board, a transformer, a heat sink, a magnetic device, a grid filter, an electromagnetic interference filter, a power tool, a power tool with a battery pack, an electric vehicle, an electric scooter, a laptop computer, a notebook computer, a large battery system, and the like. As a further example, in some embodiments, the protected element 102 may include, or could be, a semiconductor or a semiconductor chip.

[0051] In some embodiments, the thermal protection system 100 may also include a temperature sensing tape 106. It should be understood that the temperature sensing tape 106 can be thermally coupled to the protected element 102 by, for example, adhering the temperature sensing tape 106 to the protected element 102 or embedding the temperature sensing tape 106 on the protected element 102, with any temperature sensing element of the temperature sensing tape 106 aligned to the area where temperature sensing is required. For example, the temperature sensing elements of the temperature sensing tape 106 may be positioned on, above, or above the surface of a plurality of cells 104a, 104b, 104c, 104d of the protected element 102. In particular, each temperature sensing element of the temperature sensing tape 106 may be positioned to be under the thermal influence of one of the multiple cells 104a, 104b, 104c, and 104d, and as a result, a temperature rise in one of the multiple cells 104a, 104b, 104c, and 104d may cause a temperature rise in the associated temperature sensing element among the temperature sensing elements positioned on it.

[0052] In some embodiments, the thermal protection system 100 may also include a control element 112 that can be electrically connected to a temperature sensing tape 106, for example, any flexible conductor or temperature sensing element of the temperature sensing tape 106, and can be configured to monitor the resistance or impedance of the temperature sensing tape 106. In some embodiments, the control element 112 may be operably connected to a disconnection switch 110 that can be electrically connected in series between the element to be protected 102 and the load 108. For example, in some embodiments, the control element 112 may include a digital control element such as an ASIC, microprocessor, and the like, and in some embodiments, the disconnection switch 110 may include an FET, relay, and the like.

[0053] During normal operation of the thermal protection system 100, the protected element 102 can supply power to the load 108, and the temperatures in the multiple cells 104a, 104b, 104c, and 104d may be within the normal operating range, for example, below 60 degrees, below 80 degrees, and so on. However, if a high-temperature condition occurs (i.e., a trigger event, a thermal event, etc.), the temperature of any of the multiple cells 104a, 104b, 104c, and 104d may rise above the normal operating range, which may cause a temperature rise in the associated temperature sensing element among the temperature sensing elements of the temperature sensing tape 106. In some embodiments, the high-temperature condition may be caused by exposure to an external heat source, for example, by leaving the protected element 102 in sunlight, or by an overcurrent condition caused by an internal fault of the protected element 102, such as a short circuit.

[0054] Figure 2 is a top view showing a temperature sensing tape 200 according to the disclosed embodiment. It should be understood that the temperature sensing tape 200 may include a temperature sensing tape 106.

[0055] As shown in the figure, the temperature sensing tape 200 may include an insulating support structure 202, such as a flexible substrate. In some embodiments, the insulating support structure 202 may include a strip of dielectric material having an adhesive material on one or both sides for adhering the temperature sensing tape 200 to one or more surfaces of one or more protected elements, such as the protected element 102. For example, in some embodiments, the insulating support structure 202 may include Scotch tape, polyvinyl chloride (PVC) tape, Mylar, and the like. In addition, or alternatively, in some embodiments, the insulating support structure 202 may include cloth or woven material. In any embodiment, the insulating support structure 202 may be sufficiently flexible to be applied to any one or more surfaces that a person skilled in the art would desire, including multiple surfaces, curved surfaces, and the like that extending at angles to one another. In some embodiments, the adhesive material may be applied to the underside of the insulating support structure 202.

[0056] In some embodiments, the temperature sensing tape 200 may also include a plurality of temperature sensing elements 204a, 204b, 204c that are electrically connected in series, arranged on an insulating support structure 202, and spaced apart from each other along the length of the insulating support structure 202. In some embodiments, the temperature sensing elements 204a, 204b, 204c may include polymer positive temperature coefficient (PPTC) sensors or devices and / or printed temperature indicator (PTI) sensors or devices.

[0057] In Figure 2, the temperature sensing tape 200 is shown to include three temperature sensing elements 204a, 204b, and 204c, but it should be understood that the embodiments disclosed herein are not limited in this way. Instead, the temperature sensing tape 200 may include more or fewer than three temperature sensing elements 204a, 204b, and 204c, and any number that a person skilled in the art might desire. For example, in some embodiments, the number of temperature sensing elements 204a, 204b, and 204c may be determined by the length of the temperature sensing tape 200, and in some embodiments, the number of temperature sensing elements 204a, 204b, and 204c may be determined by the distance between them. In this regard, the temperature sensing elements 204a, 204b, and 204c are shown to be evenly spaced in Figure 2, but it should be understood that the embodiments disclosed herein are not limited in this way. Alternatively, the temperature sensing elements 204a, 204b, and 204c may be arranged at regular or irregular intervals along the length of the insulating support structure 202, as may be specified or required by the specific application of the temperature sensing tape 200.

[0058] As described above, the adhesive material may be applied, for example, to the underside of the insulating support structure 202. In some embodiments, the adhesive material may be applied only to the portion or location of the insulating support structure 202 corresponding to the temperature sensing elements 204a, 204b, 204c on its upper surface, on the underside of the insulating support structure 202. That is, the adhesive material may be applied on the opposing surface of the insulating support structure 202, beneath the temperature sensing elements 204a, 204b, 204c, thereby improving thermal contact with the surface to which it is bonded. In addition, or alternatively, in some embodiments, the adhesive material may include one or more additives having high thermal conductivity, such as high thermal conductivity powders, to further improve thermal contact with the surface to which it is bonded. For example, additives having high thermal conductivity may include intrinsic (low conductivity) ZnO, Al2O3, or AlN diamond paste, and high thermal conductivity conductive particles including ceramic, metal, or carbon-based particles, fibers, and similar.

[0059] According to embodiments of the resistor ladder disclosed herein and shown in Figure 2, each resistor 206a, 206b may be connected in parallel between each of the plurality of temperature sensing elements 204a, 204b, 204c and may be arranged on an insulating support structure 202. In some embodiments, each resistor 206a, 206b connected in parallel between each of the plurality of temperature sensing elements 204a, 204b, 204c may include a high-resistance, low-temperature-coefficient material, such as a printed metal oxide varistor (MOV) material. During operation, if a trigger event is detected by one of the plurality of temperature sensing elements 204a, 204b, 204c, the impedance of that one of the plurality of temperature sensing elements 204a, 204b, 204c may change, thereby creating an open circuit in the plurality of temperature sensing elements 204a, 204b, 204c downstream of the temperature sensing element 204a that detected the trigger event.

[0060] As shown in Figure 2, the temperature sensing tape 200 may be placed on or inside the insulating support structure 202 and may include a plurality of temperature sensing elements 204a, 204b, 204c, and flexible conductors 208 electrically connected to resistors 206a, 206b connected in parallel between each of the plurality of temperature sensing elements 204a, 204b, 204c. Thus, the conductive circuit of the temperature sensing tape 200 may include a plurality of temperature sensing elements 204a, 204b, 204c, resistors 206a, 206b connected in parallel between each of the plurality of temperature sensing elements 204a, 204b, 204c, and flexible conductors 208, and the output voltage of the conductive circuit may indicate which of the plurality of temperature sensing elements 204a, 204b, 204c has detected a trigger event.

[0061] In some embodiments, the flexible conductor 208 may include elongated segments of flexible conductive material that can be bonded to, printed on, incorporated into, or otherwise applied to the insulating support structure 202. For example, in some embodiments, the flexible conductor 208 may include copper mesh, silver epoxy, conductive ink, metal wire or ribbon, and the like. Thus, in some embodiments, the flexible conductor 208 may take the form of a flat foil, a wire with a circular cross-section, a single wire, a multi-strand wire, a flat wire, a rod, and the like.

[0062] Figure 3 is a circuit diagram showing the conductive circuit 300 of the temperature sensing tape according to the disclosed embodiment. It should be understood that the conductive circuit 300 may represent the temperature sensing tape 200.

[0063] As shown in Figure 3, the conductive circuit 300 may include a plurality of temperature sensing elements 302 separated by a parallel resistor 304. The conductive circuit 300 may also include a pull-up resistor 306 at one end of the conductive circuit 300. In these embodiments, the output voltage may be measured at the pull-up resistor 306.

[0064] Although not specifically shown in Figure 3, in some embodiments the conductive circuit 300 may also include an amplification circuit electrically connected thereto.

[0065] Figures 4A, 4B, and 4C are graphs 402, 404, and 406, respectively, showing the output voltage and the activated temperature sensing elements in a temperature sensing tape having resistors with tolerances of 0%, 1%, and 5% according to the disclosed embodiments. As shown, different of the multiple temperature sensing elements 204a, 204b, and 204c that detected the trigger event may produce different levels of output voltage.

[0066] If more than one of the multiple temperature sensing elements 204a, 204b, and 204c detect a trigger event, a double scan performed once from each end of the conductive circuit can identify two of the multiple temperature sensing elements 204a, 204b, and 204c that detected the trigger event, and thus the boundary of the heated area can be identified. In this regard, Figure 5A is a circuit diagram showing the conductive circuit 500 of the temperature sensing tape during the first scan in the double scan, and Figure 5B is a circuit diagram showing the conductive circuit 500 during the second scan in the double scan. During the first scan, the first output voltage at the first end of the conductive circuit 500 can identify the first temperature sensing element among the multiple temperature sensing elements 204a, 204b, and 204c that detected the trigger event, and during the second scan, the second output voltage at the second end of the conductive circuit 500 can identify the second temperature sensing element among the multiple temperature sensing elements 204a, 204b, and 204c that detected the trigger event.

[0067] According to the above, Figure 6 is a graph 600 showing a comparison between the output voltage and the activated temperature sensing element in a double scan of a temperature sensing tape according to the disclosed embodiment.

[0068] According to the TDR embodiment disclosed herein, Figure 7 is a block diagram of a thermal protection system 700 according to the disclosed embodiment, in which pulses are injected into and reflected by the temperature sensing tape. Similar to the resistor ladder embodiment disclosed above, the temperature sensing tape 702 may comprise an insulating support structure, a plurality of temperature sensing elements electrically connected in series and positioned on the insulating support structure, and a flexible conductor positioned on the insulating support structure and arranged in series with the plurality of temperature sensing elements to form a conductive circuit, provided that parallel resistors are not required in the conductive circuit.

[0069] Alternatively, the incident pulse signal 704 may be injected into the conductive circuit by, for example, a pulse generator 708. If a trigger event is detected by one of the multiple temperature sensing elements, the impedance of the temperature sensing element that detected the trigger event may change, and instead of passing the incident pulse signal 704 through it, the temperature sensing element that detected the trigger event may reflect the incident pulse signal 704 as a reflected pulse signal 706 due to an impedance mismatch in the conductive circuit. In particular, when a trigger event is detected, the impedance of one of the multiple temperature sensing elements may change, which may cause an open circuit in the multiple temperature sensing elements downstream of that one.

[0070] Accordingly, the timing and speed of the incident pulse signal 704 and / or reflected pulse signal 706 can be measured in the thermal protection system 700, for example, by a detection device 710. In particular, in some embodiments, the detection device 710 can measure, calculate, and / or determine the time difference between the incident pulse signal 704 and the reflected pulse signal 706, which may indicate which of the multiple temperature sensing elements detected the trigger event. In particular, different time differences may correspond to different of the multiple temperature sensing elements that were activated by the detection of the trigger event. For example, in some embodiments, the time difference can be identified in a lookup table relating to the temperature sensing tape 702 to identify which of the multiple temperature sensing elements detected the trigger event. In addition, or alternatively, in some embodiments, the detection device 710 can measure, calculate, and / or determine the propagation speed of the incident pulse signal 704 and / or the reflected pulse signal 706, as well as the time difference between the incident pulse signal 704 and the reflected pulse signal 706, and the distance to one of the multiple temperature sensing elements can be identified by multiplying the propagation speed of the incident pulse signal 704 by the time difference and dividing the product by 2.

[0071] As described above, Figure 8 is a graph 800 showing the incident pulse signal and the reflected pulse signal from the activated temperature sensing element in a temperature sensing tape according to the disclosed embodiment. In some embodiments, the resolution can be improved by optimized waveguide characteristics and / or narrower pulses.

[0072] Figure 9 shows another temperature sensing tape 900 according to a disclosed embodiment. In some embodiments, if there are no multiple temperature sensing elements 902 that are activated by detecting a trigger event, the conductive circuits of the temperature sensing tape 900 may have a uniform impedance, and as a result, a reflected pulse signal is generated only when one of the multiple temperature sensing elements 902 detects a trigger event. For example, the impedance of a flexible conductor 904 in the temperature sensing tape 900 may be matched to the impedance of the multiple temperature sensing elements 902, which may be matched to the impedance of a pulse generator that is the source of the incident pulse signal. In particular, and as shown in Figure 9, a flexible conductor 904 placed between two of the multiple temperature sensing elements 902 may be formed in a wavy shape, which may increase the length of the flexible conductor and the electrical distance over which the incident and reflected pulse signals travel without increasing the physical distance between two of the multiple temperature sensing elements 902.

[0073] In addition to changing the impedance of the flexible conductor 904, in some embodiments, the speed of the incident pulse signal and the reflected pulse signal can be reduced by increasing the inductance and / or capacitance of various elements in the temperature sensing tape, including the flexible conductor 904 and / or a plurality of temperature sensing elements 902.

[0074] Where used herein, elements or steps described in the singular and beginning with the word "a" or "an" should be understood not to exclude multiple elements or steps unless such exclusion is expressly stated. Furthermore, references to “one embodiment” in this disclosure are not intended to be construed as excluding the existence of additional embodiments that also incorporate the enumerated features.

[0075] While this disclosure refers to specific embodiments, multiple modifications, alterations, and changes are possible to the embodiments described without departing from the spirit and scope of this disclosure as defined in the appended claims. Therefore, this disclosure is not limited to the embodiments described, and is intended to encompass the entire scope defined by the following claims and their equivalents.

Claims

1. Insulating support structure; Multiple temperature sensing elements electrically connected in series and arranged on the insulating support structure; and Each of the resistors connected in parallel between each of the plurality of temperature sensing elements and placed on the insulating support structure Equipped with, A trigger event detected by one of the plurality of temperature sensing elements causes a change in the impedance of the one of the plurality of temperature sensing elements, and causes an open circuit in the plurality of temperature sensing elements downstream of the one of the plurality of temperature sensing elements. Temperature-sensing tape.

2. A conductive circuit having the plurality of temperature sensing elements, the respective resistors connected in parallel between each of the plurality of temperature sensing elements, and a flexible conductor disposed on the insulating support structure between them. Furthermore, The output voltage of the conductive circuit indicates which of the multiple temperature sensing elements detected the trigger event. The temperature sensing tape according to claim 1.

3. A pull-up resistor is connected to one end of the conductive circuit. Furthermore, The output voltage is measured in the pull-up resistor. The temperature sensing tape according to claim 2.

4. Amplifier circuit electrically connected to the aforementioned conductive circuit The temperature sensing tape according to claim 2, further comprising the above.

5. A conductive circuit having the plurality of temperature sensing elements, the respective resistors connected in parallel between each of the plurality of temperature sensing elements, and a flexible conductor disposed on the insulating support structure between them. Furthermore, The first output voltage at the first end of the conductive circuit identifies the first temperature sensing element among the plurality of temperature sensing elements that detected the trigger event. The second output voltage at the second end of the conductive circuit identifies the second temperature sensing element among the plurality of temperature sensing elements that detected the trigger event. A temperature sensing tape according to any one of claims 1 to 4.

6. The temperature sensing tape according to any one of claims 1 to 4, wherein the plurality of temperature sensing elements have polymer positive temperature coefficient (PPTC) sensors or printed temperature indicator (PTI) sensors, and each of the resistors connected in parallel between each of the plurality of temperature sensing elements has a high resistance low temperature coefficient material.

7. Insulating support structure; Multiple temperature sensing elements electrically connected in series and arranged on the insulating support structure; and A flexible conductor is disposed on the insulating support structure and arranged in series with the plurality of temperature sensing elements to form a conductive circuit. Equipped with, A trigger event detected by one of the plurality of temperature sensing elements causes a change in the impedance of that one of the plurality of temperature sensing elements, and causes the incident pulse signal injected into the conductive circuit to be reflected as a reflected pulse signal by that one of the plurality of temperature sensing elements. Temperature-sensing tape.

8. The temperature sensing tape according to claim 7, wherein the time difference between the incident pulse signal and the reflected pulse signal indicates which of the plurality of temperature sensing elements detected the trigger event.

9. The temperature sensing tape according to claim 7 or 8, wherein the conductive circuit has a uniform impedance in the absence of the trigger event.

10. The temperature sensing tape according to claim 9, wherein the flexible conductor disposed between two of the plurality of temperature sensing elements is formed in a wave shape, and the length of the flexible conductor and the electrical distance over which the incident pulse signal and the reflected pulse signal are transmitted are increased without increasing the physical distance between the two of the plurality of temperature sensing elements.

11. The temperature sensing tape according to claim 7 or 8, wherein an increase in the inductance and capacitance of the temperature sensing tape reduces the speed of the incident pulse signal and the reflected pulse signal.

12. The step in which one of several temperature sensing elements of a conductive circuit, which is electrically connected in series with a flexible conductor and positioned on an insulating support structure of the temperature sensing tape, detects a trigger event; In response to detecting the trigger event, the step of changing the impedance of one of the plurality of temperature sensing elements to create an open circuit in the plurality of temperature sensing elements downstream of the one of the plurality of temperature sensing elements; and The step of outputting an output signal from the conductive circuit. Equipped with, The output signal indicates which of the plurality of temperature sensing elements detected the trigger event. method.

13. The method according to claim 12, wherein each resistor is connected in parallel between each of the plurality of temperature sensing elements, and the output signal includes an output voltage.

14. A step of measuring the output voltage in a pull-up resistor located at one end of the conductive circuit; and In the lookup table for the temperature sensing tape, the step of identifying which of the plurality of temperature sensing elements corresponds to the output voltage. The method according to claim 13, further comprising the above.

15. The step of amplifying the output voltage using an amplification circuit electrically connected to the conductive circuit. The method according to claim 13, further comprising the above.

16. A step of measuring the output voltage at the first end of the conductive circuit and identifying the first temperature sensing element among the plurality of temperature sensing elements that detected the trigger event; and The step of measuring the output voltage at the second end of the conductive circuit to identify the second temperature sensing element among the plurality of temperature sensing elements that detected the trigger event. The method according to claim 13, further comprising the above.

17. The method according to any one of claims 12 to 16, wherein the output signal includes a reflected pulse signal which is a reflection of an incident pulse signal injected into the conductive circuit and reflected by one of the plurality of temperature sensing elements.

18. A step of measuring the time difference between the incident pulse signal and the reflected pulse signal; and Step of identifying which of the plurality of temperature sensing elements corresponds to the time difference for the temperature sensing tape. The method according to claim 17, further comprising:

19. In the absence of the trigger event, the impedance of the flexible conductor is matched to the impedance of the plurality of temperature sensing elements to generate a uniform impedance in the conductive circuit. The method according to claim 17, further comprising:

20. The method according to claim 19, wherein the flexible conductor disposed between two of the plurality of temperature sensing elements is formed in a wave shape, and the length of the flexible conductor and the electrical distance over which the incident pulse signal and the reflected pulse signal are transmitted are increased without increasing the physical distance between the two of the plurality of temperature sensing elements.

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