EP-4737872-A1 - SYSTEMS AND METHODS FOR IDENTIFYING A LOCATION OF A THERMAL EVENT DETECTED BY A TEMPERATURE SENSING TAPE

EP4737872A1EP 4737872 A1EP4737872 A1EP 4737872A1EP-4737872-A1

Abstract

Systems and methods for identifying a location of a thermal event detected by a temperature sensing tape are provided. The temperature sensing tape can include a resistive ladder with parallel resistors between a plurality of temperature sensing elements to create voltage dividers, and unique analog output voltages can correspond to different ones of the plurality of temperature sensing elements being activated. Pulses injected into and reflected by the temperature sensing tape can be used detect a distance to a location where a triggering event is detected.

Inventors

Martis, Claran
PINEDA, MARTIN
GOLUBOVIC, BORIS
ZALTAUSKAS, ARNOLDAS
DOMS, MARCO
MISEVICIUS, RIMANTAS

Assignees

Littelfuse, Inc.

Dates

Publication Date: 20260506
Application Date: 20251022

Claims (15)

A temperature sensing tape comprising: an insulating support structure; a plurality of temperature sensing elements electrically connected in series and disposed on the insulating support structure; wherein a triggering event detected by one of the plurality of temperature sensing elements causes a change in impedance of the one of the plurality of temperature sensing elements.
The temperature sensing tape of claim 1, further comprising a respective resistor connected in parallel between each of the plurality of temperature sensing elements and disposed on the insulating support structure.
The temperature sensing tape of claim 1 or 2, wherein the triggering event further causes an open circuit in the plurality of temperature sensing elements downstream of the one of the plurality of temperature sensing elements.
The temperature sensing tape of any of the preceding claims, further comprising: a conductive circuit that includes the plurality of temperature sensing elements, the respective resistor connected in parallel between each of the plurality of temperature sensing elements, and a flexible conductor disposed on the insulating support structure therebetween, wherein an output voltage of the conductive circuit indicates which of the plurality of temperature sensing elements detected the triggering event.
The temperature sensing tape of any of the preceding claims, further comprising: a pull up resistor at one end of the conductive circuit, wherein the output voltage is measured at the pull up resistor, and/or further comprising: an amplifier circuit electrically connected to the conductive circuit.
The temperature sensing tape of any of the claims 1-3, further comprising: a conductive circuit that includes the plurality of temperature sensing elements, the respective resistor connected in parallel between each of the plurality of temperature sensing elements, and a flexible conductor disposed on the insulating support structure therebetween, wherein a first output voltage at a first end of the conductive circuit identifies a first of the plurality of temperature sensing elements detecting the triggering event, and wherein a second output voltage at a second end of the conductive circuit identifies a second of the plurality of temperature sensing elements detecting the triggering event.
The temperature sensing tape of any of the preceding claims, wherein the plurality of temperature sensing elements includes a polymeric positive temperature coefficient (PPTC) sensor or a printed temperature indicator (PTI) sensor, and wherein the respective resistor connected in parallel between each of the plurality of temperature sensing elements includes a low-temperature coefficient material with high resistance.
The temperature sensing tape of claim 1, further comprising: a flexible conductor disposed on the insulating support structure and arranged in series with the plurality of temperature sensing elements to form a conductive circuit, wherein the triggering event further causes an incident pulse signal injected into the conductive circuit to be reflected by the one of the plurality of temperature sensing elements as a reflected pulse signal, preferably wherein a time difference between the incident pulse signal and the reflected pulse signal indicates which of the plurality of temperature sensing elements detected the triggering event.
The temperature sensing tape of any of the claims 6-8, wherein the conductive circuit has a uniform impedance absent the triggering event.
The temperature sensing tape of any of the claims 6-9, wherein the flexible conductor disposed between two of the plurality of temperature sensing elements is wave-shaped to increase a length of the flexible conductor and an electrical distance that the incident pulse signal and the reflected pulse signal travel without increasing a physical distance between the two of the plurality of temperature sensing elements.
The temperature sensing tape of any of the claims 6-10, wherein increasing inductance and capacitance of the temperature sensing tape slows down the incident pulse signal and the reflected pulse signal.
A method comprising: detecting a triggering event by one of a plurality of temperature sensing elements of a conductive circuit electrically connected in series with a flexible conductor and disposed on an insulating support structure of a temperature sensing tape; changing an impedance of the one of the plurality of temperature sensing elements responsive to detecting the triggering event 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, wherein the output signal is indicative of which of the plurality of temperature sensing elements detected the triggering event.
The method of claim 12, wherein a respective resistor is connected in parallel between each of the plurality of temperature sensing elements, and wherein the output signal includes an output voltage, preferably further comprising: measuring the output voltage at a pull up resistor located at one end of the conductive circuit; and identifying which of the plurality of temperature sensing elements corresponds with the output voltage in a lookup table for the temperature sensing tape, and/or amplifying the output voltage with an amplifier circuit electrically connected to the conductive circuit.
The method of claim 13, further comprising: measuring the output voltage at a first end of the conductive circuit to identify a first of the plurality of temperature sensing elements detecting the triggering event; and measuring the output voltage at a second end of the conductive circuit to identify a second of the plurality of temperature sensing elements detecting the triggering event.
The method of any of the claims 12-14, wherein the output signal includes a reflected pulse signal that is a reflection of an incident pulse signal injected into the conductive circuit and reflected by the one of the plurality of temperature sensing elements, preferably further comprising: 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 with the time difference for the temperature sensing tape, and/or further comprising: matching an impedance of the flexible conductor with the impedance of the plurality of temperature sensing elements absent the triggering event to create a uniform impedance in the conductive circuit, preferably wherein the flexible conductor disposed between two of the plurality of temperature sensing elements is wave-shaped to increase a length of the flexible conductor and an electrical distance that the incident pulse signal and the reflected pulse signal travel without increasing a physical distance between the two of the plurality of temperature sensing elements.

Description

The present application claims the benefit of priority to U.S. Provisional Application Serial No. 63/713,851, entitled "SYSTEMS AND METHODS FOR IDENTIFYING A LOCATION OF A THERMAL EVENT DETECTED BY A TEMPERATURE SENSING TAPE" and filed October 30, 2024. FIELD The present disclosure generally relates to temperature sensing devices. More particularly, the present disclosure relates to systems and methods for identifying a location of a thermal event detected by a temperature sensing tape. BACKGROUND Electrical systems and devices, such as batteries and semiconductors, for example, can be damaged by high temperature conditions if such conditions are allowed to persist. Therefore, it is common for electrical systems and devices to be equipped with temperature sensing devices that can be used to measure temperature variations at discrete locations in or on the electrical systems or devices. For example, if a measured temperature exceeds a predetermined threshold, an associated electrical system or device being protected may automatically shut off until such a condition subsides or is remedied, thereby preventing or mitigating any damage to the associated electrical system or device. Some known temperature sensing devices include a temperature sensing tape that includes temperature sensing elements at discrete locations thereon or therein. These devices output a digital signal (e.g., high or low) to identify a thermal event, but do not identify a location of the thermal event. Accordingly, if the temperature sensing tape is affixed to an electrical system, such as a battery pack, an output signal will only identify that the battery pack is experiencing a thermal event, but will not identify which cell in the battery pack is experiencing the thermal event. It is with respect to these and other considerations that the present disclosure may be useful. BRIEF SUMMARY This Brief Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Brief Summary is not intended to identify key features or essential features of claimed subject matter or intended as an aid in determining scope of the claimed subject matter. A temperature sensing tape may include an insulating support structure, a plurality of temperature sensing elements electrically connected in series and disposed on the insulating support structure, and a respective resistor connected in parallel between each of the plurality of temperature sensing elements and disposed on the insulating support structure. A triggering event detected by one of the plurality of temperature sensing elements can cause a change in impedance of the one of the plurality of temperature sensing elements and an open circuit in the plurality of temperature sensing elements downstream of the one of the plurality of temperature sensing elements. The temperature sensing tape can include a conductive circuit that can include the plurality of temperature sensing elements, the respective resistor connected in parallel between each of the plurality of temperature sensing elements, and a flexible conductor disposed on the insulating support structure therebetween. An output voltage of the conductive circuit can indicate which of the plurality of temperature sensing elements detected the triggering event. The temperature sensing tape can include a pull up resistor at one end of the conductive circuit, and the output voltage can be measured at the pull up resistor. The temperature sensing tape can include an amplifier circuit electrically connected to the conductive circuit. The temperature sensing tape can include a conductive circuit that can include the plurality of temperature sensing elements, the respective resistor connected in parallel between each of the plurality of temperature sensing elements, and a flexible conductor disposed on the insulating support structure therebetween. A first output voltage at a first end of the conductive circuit can identify a first of the plurality of temperature sensing elements detecting the triggering event, and a second output voltage at a second end of the conductive circuit can identify a second of the plurality of temperature sensing elements detecting the triggering event. The plurality of temperature sensing elements can include a polymeric positive temperature coefficient (PPTC) sensor or a printed temperature indicator (PTI) sensor, and the respective resistor connected in parallel between each of the plurality of temperature sensing elements can include a low-temperature coefficient material with high resistance. A temperature sensing tape can include an insulating support structure, a plurality of temperature sensing elements electrically connected in series and disposed on the insulating support structure, and a flexible conductor disposed on the insulating support structure and arranged in series with the plurality of temperature sensing elements to form a con