Thermistor system for electronic shower valve

Abstract

A thermistor system for use with an electronic shower valve, including a primary thermistor within a fluid passageway of the shower valve and a secondary thermistor positioned in spaced relation to the primary thermistor. An electronic controller receives temperature measurement data from the first thermistor and the second thermistor, analyzes the received temperature measurement data to determine the presence of an anomaly, and mitigates the anomaly. The electronic controller operates the valve dependent upon the received temperature measurement data.

Description

THERMISTOR SYSTEM FOR ELECTRONIC SHOWER VALVECross-Reference to Related Application

[0001] The present application claims priority to U.S. Provisional Patent Application Serial No. 63 / 616,733, filed December 31, 2023, the disclosure of which is expressly incorporated herein by reference.Background and Summary of the Disclosure

[0002] The present disclosure relates to a system and method for measuring water temperature within an electronic shower valve.

[0003] It is known to use thermistors to determine the water temperature in an electronic shower. A thermistor is a device whose resistance changes as its temperature changes. The electronic valve changes the hot and cold water mixture ratio based on the output of the thermistor and, therefore, has a direct impact on the satisfaction, comfort and safety of the shower user. The electronic valve changes the mix ratio based on user input, trying to match the thermistor output to the user's requested shower temperature. The electronic valve also maintains the desired shower temperature when the inlet hot and cold supply water conditions change, either through changes in pressure or temperature. Because the thermistor relies on resistance to correlate to temperature, changes in resistance of components along the circuit between the thermistor and the electronic measurement point may result in erroneous readings, causing a discrepancy between the displayed and actual water temperature.

[0004] To confirm the accuracy of the resistance measurement relative to actual temperature, a second or reference thermistor can be added to the system to provide a redundant reference. However, this second measurement may have downsides. This second thermistor adds technical complexity to the valve system. If co-located in the probe housing with the first thermistor, the second thermistor may add mass to the probe assembly, which increases the response time. If the second thermistor is located separately or remotely from the first thermistor, the second thermistor may require an additional penetration into the waterway, which creates another potential leak point. The second thermistor may have a temperature profile that is different from that of the first thermistor. In addition, if the second reference thermistor is located along the same wiring pathway as the first thermistor, it maybe subject to matching system failures (e.g., corrosion, damage, etc.) that will appear in both thermistors simultaneously.

[0005] If a separate, second thermistor is located along a completely separate pathway from the first thermistor, the independence of the two thermistor references may be assured. In addition, the second thermistor may be located directly on the circuit board of the electronic valve, thereby eliminating the variability of connectors. However, the separation of the two thermistors may cause them to not have the same environmental temperature.

[0006] The present disclosure provides a system configured to wait until the electronic shower valve has not been used for a period of time and then compare the outputs of the two thermistors when the environment has reached a stable temperature. After several hours of inoperation, all of the components in the shower system revert back to the environmental or ambient temperature, given their close physical proximity to each other. Another benefit of a separate thermistor is that it can be measured continuously, during both shower usage and periods of non-use. The data can be tracked and the development of discontinuities and drifts can be monitored over long periods of time.

[0007] According to an illustrative embodiment of the present disclosure, an electronic shower system includes an electronically operable valve having a valve body defining a fluid passageway. A first thermistor extends at least partially within the fluid passageway to measure the temperature of fluid passing therethrough. A second thermistor is positioned in spaced relation to the first thermistor. An electronic controller is in electrical communication with the first thermistor and the second thermistor. The electronic controller receives temperature measurement data from the first thermistor and the second thermistor, analyzes the received temperature measurement data to determine the presence of an anomaly, and mitigates the anomaly. The electronic controller operates the valve dependent upon the received temperature measurement data.

[0008] According to another illustrative embodiment of the present disclosure, an electronic shower system includes an electronically operable valve having a valve body defining a fluid passageway. A first thermistor extends at least partially within the fluid passageway to measure the temperature of fluid passing therethrough. A second thermistor is in spaced relation to the first thermistor. A controller is in electrical communication with the first thermistor and the second thermistor. The controller receives temperature measurement data from the first thermistor and the second thermistor, operates the valve dependent uponthe received temperature measurement data, and analyzes the received temperature measurement data to determine changes in measured temperatures over time. If the changes in the measured temperatures exceed a threshold, then the controller responds to the changes in the measured temperatures exceeding the threshold by notifying a human user that the electronic shower system needs maintenance.100091 According to yet another illustrative embodiment of the present disclosure, a method of operating an electronic shower system includes providing an electronically operable valve including a valve body defining a fluid passageway. First temperature measurements of a temperature of fluid passing through the fluid passageway are taken at a first location. Second temperature measurements of the electronic shower system are taken at a second location spaced from the first location. The valve is operated dependent upon the first temperature measurements. The first temperature measurements and the second temperature measurements are analyzed to determine the presence of an anomaly. The anomaly is mitigated.

[0010] Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of illustrative embodiments exemplifying the best mode of carrying out the invention as presently perceived.Brief Description of the Drawings

[0011] The foregoing aspects and many of the intended advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description of exemplary embodiments when taken in conjunction with the accompanying drawings, wherein:

[0012] FIG. 1 is an upper perspective view of an illustrative electronic shower system of the present disclosure;

[0013] FIG. 2 is a partially exploded, upper, front perspective view of the user interface of the electronic shower system of FIG. 1 and an illustrative electronic valve assembly of the present disclosure for use with the thermistor system of the present disclosure;

[0014] FIG. 3 is an enlarged perspective view of the illustrative electronic valve assembly of FIG. 2;

[0015] FIG. 4 is a cross-sectional view taken along line 4—4 of FIG. 3;

[0016] FIG. 5 is a partially exploded, upper, rear perspective view of the user interface of the electronic shower system of FIG. 1 ; and

[0017] FIG. 6 is a block diagram of the illustrative thermistor system of FIG. 2.

[0018] Corresponding reference characters indicate corresponding parts throughout the several view. Although the drawings represent exemplary embodiments of various features and components according to the present disclosure, the drawings are not necessarily to scale and certain features may be exaggerated in order to better illustrate exemplary embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.Detailed Description of the Drawings

[0019] For the purposes of promoting and understanding the principles of the present disclosure, reference will now be made to the embodiments illustrated in the drawings, which are described herein. The embodiments disclosed herein are not intended to be exhaustive or to limit the invention to the precise form disclosed. Rather, the embodiments are chosen and described so that others skilled in the art may utilize their teachings. Therefore, no limitation of the scope of the claimed invention is thereby intended. The present invention includes any alterations and further modifications of the illustrated devices and described methods and further applications of principles in the invention which would normally occur to one skilled in the art to which the invention relates.

[0020] With reference initially to FIGS. 1 and 2, an illustrative shower system 2 of the present disclosure includes an electronic user interface 44 by which a human user can control the flow and temperature of water emitted by a fluid delivery device, such as a showerhead 4 within a shower enclosure 6 defined by walls 7a, 7b, 7c extending upwardly from a base 8. The user interface 44 may be coupled to a rear wall 7b and include a touch- sensitive screen (“touch screen”) 9 for receiving manual inputs from the user and for displaying menus, messages and other information to the user. The user interface 44 may be electrically connected by an electrical cable 35 (FIG. 2) to a thermistor system 10 of the present disclosure that includes an electronic shower valve 12.

[0021] With reference to FIGS. 3 and 4, the electronic shower valve 12 includes a conventional valve body or fitting 14 of the type supported within the shower wall 7b (FIG.1) for receiving an illustrative electronic valve cartridge 16. The illustrative valve body 14 includes a first or cold water inlet 18, which is configured to be fluidly coupled to a conventional cold water supply (not shown), and a second or hot water inlet 20, which is configured to be fluidly coupled to a conventional hot water supply (not shown).

[0022] The valve cartridge 16 includes a first or movable valve element 22 cooperating with a second or fixed valve element 24 to control water flow from the cold water and hot water inlets 18 and 20 to an outlet 26a, 26b via a passageway 28 extending through the valve elements 22 and 24. A first or primaiy temperature sensor 30, illustratively a thermistor, is configured to detect the temperature of water passing through the outlet 26. The thermistor 30 may be of conventional design as including a sensing probe 32 coupled to an electrical wire 34 that may be included within cable 35. An illustrative electronic shower valve including a temperature sensor is detailed in U.S. Patent Application Publication No. 2021 / 0388584 to Thomas et al., the disclosure of which is expressly incorporated herein by reference.

[0023] The illustrative thermistor system 10 includes a separate secondary or reference thermistor 46 (FIG. 5) for use with the electronic valve cartridge 16. The secondary thermistor 46 may be used for comparing its output to the output of the primary thermistor 30, which is used for temperature control. The secondary thermistor 46 is located in spaced relation to the primaiy thermistor 30. That is, the secondary thermistor 46 may be disposed at a location that is remote from the location of the primary thermistor 30. In one embodiment, the secondary thermistor 46 is disposed approximately between an inch and two feet away from the primary thermistor 30. As illustrated in FIG. 5, the secondary thermistor 46 may be supported on a circuit board 48 within a shell 45 of the user interface 44 in order to avoid wiring issues or variations in the environment in which the secondary thermistor 46 is disposed. It is also possible for the secondary thermistor to be disposed either on the valve body 14 and / or in the water flow, as is primary thermistor 30. User interface 44 further includes a watertight plastic or rubber seal 47 that prevents water from the electronic shower valve 12 from reaching circuit board 48. A gasket 49 may seal a gap between the edges or perimeter of the shell 45 and the shower wall 7b.

[0024] The wire 34 provides communication between the sensing probe 32 and an electronic processor in the form of a controller 40 (FIG. 6) including a memory device 42.Controller 40 and other electronics may be supported by the circuit board 48. The user interface 44 is illustratively in electrical communication with the controller 40.

[0025] An optional third thermistor 50 may be provided in the water flow on the valve body 14, with the second thermistor 46 being on the circuit board 48, as shown in FIG.6. The additional temperature data provided by the third thermistor may enable the controller 40 to better determine the components that require service or replacement and the location of those components. A fourth thermistor, fifth thermistor, etc. may be added at various locations to provide further temperature data for better determinations and analysis by the controller 40. If one of the three or more thermistors is determined to be malfunctioning, the controller 40 may ignore future temperature readings from the malfunctioning thermistor, and continue normal operation with the remaining operable thermistors.

[0026] The electronic processor 40 used to control the valve 16 waits until the shower has not been used for an extended period time (illustratively two to three hours) and then compares the outputs or resistances of the primary and reference thermistors 30 and 46 to insure there has not been a change in measurement system resistance. These resistance values may correspond to temperature measurements, and the temperature measurements may be derived from the resistance values based on a predetermined lookup table, for example. Typically, as the temperature increases, the resistance of the thermistor decreases.

[0027] The resistance data can be stored in the memory 42 for the controller 40 to analyze over a period of time. The secondary thermistor 46 measures the air temperature and the primary thermistor 30 measures the water temperature, but after a period of time of inoperation or inactivity of the shower, the air temperature and the water temperature stabilize and converge to a common temperature. A shower valve such as shower valve 16 typically is unused for a large portion of the day and sits idle. If a family of four people each take a twenty-minute shower per day, then the valve is only used 5 percent of the twenty- four-hour day and those times of usage are generally limited to morning and evening hours.

[0028] The main components of the thermistor system 10 include the primary thermistor 30 used to measure water temperature and the secondary thermistor 46 located separately or remotely for reference or comparison. The electronic controller 40 measures the resistances or outputs of the two thermistors after the shower valve 16 has not be used for a period of time (e.g., 2-3 hours) and compares the resistance or output values to each other to verify that they indicate approximately the same temperature. If they do not indicateapproximately the same temperature, then it may indicate that one of the thermistors or their associated circuitry has deteriorated and requires repair or maintenance. The controller 40 may cause a message to be presented on the touch-sensitive screen 9 of the user interface 44 in order to notify the user that maintenance or repair is required.

[0029] The resistance values or outputs of thermistors 30, 46 may also be compared to their own previous resistance values or outputs as stored in memory 42 to determine if the resistance values or outputs have changed over time, which could also indicate that one of the thermistors or their associated circuitry has deteriorated and requires repair or maintenance. More particularly, after an extended period of inactivity of the shower valve 16, both thermistors 30 and 46 have reached a steady state. Both measured temperatures at this steady state condition are then stored in the memory 42. The measured temperatures stored in memory 42 are then analyzed for change over time. The change over time can provide an indication of the condition of the thermistors 30 and 46. The measured temperature values can indicate that the thermistors 30, 46 are in good operating condition or whether some anomaly is present. Examples of such an anomaly include attention / service being required or one of the thermistors malfunctioning. For example, no changes in the measured temperatures over time may indicate that the thermistors 30, 46 are in good operating condition. Small changes in the measured temperatures over time may indicate that the thermistors 30, 46 require attention / service. Large changes in the measured temperatures over time may indicate that at least one of the thermistors 30, 46 is malfunctioning. The results of this analysis by the controller 40 may be presented to the user via the touch- sensitive screen 9 of the user interface 44. If one of the thermistors 30, 46 is malfunctioning, the controller 40 may deactivate the valve 16 for safety considerations.

[0030] Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the spirit and scope of the invention as described and defined in the following claims.

Claims

WHAT IS CLAIMED IS:

1. An electronic shower system comprising: an electronically operable valve including a valve body defining a fluid passageway; a first thermistor extending at least partially within the fluid passageway to measure the temperature of fluid passing therethrough; a second thermistor in spaced relation to the first thermistor; and a controller in electrical communication with the first thermistor and the second thermistor, the controller being configured to: receive temperature measurement data from the first thermistor and the second thermistor; operate the valve dependent upon the received temperature measurement data; analyze the received temperature measurement data to determine a presence of an anomaly; and mitigate the anomaly.

2. The electronic shower system of claim 1, wherein the second thermistor is positioned in the environment to measure ambient air temperature.

3. The electronic shower system of claim 1, wherein the second thermistor is positioned on a circuit board and in thermal communication with the fluid passageway.

4. The electronic shower system of claim 1, wherein the second thermistor is extended at least partially within the fluid passageway.

5. The electronic shower system of claim 1, wherein the controller is configured to determine the presence of an anomaly based on differences in temperature measurements over time.

6. The electronic shower system of claim 1, further comprising a user interface, the electronic controller being configured to mitigate the anomaly by using the user interface to notify a human user about the anomaly.

7. The electronic shower system of claim 1, wherein the second thermistor is positioned on a circuit board, the system further comprising a third thermistor extended at least partially within the fluid passageway, the controller being in electrical communication with the third thermistor and configured to receive temperature measurement data from the third thermistor.

8. An electronic shower system comprising: an electronically operable valve including a valve body defining a fluid passageway; a first thermistor extending at least partially within the fluid passageway to measure the temperature of fluid passing therethrough; a second thermistor in spaced relation to the first thermistor; and a controller in electrical communication with the first thermistor and the second thermistor, the controller being configured to: receive temperature measurement data from the first thermistor and the second thermistor; operate the valve dependent upon the received temperature measurement data; analyze the received temperature measurement data to determine changes in measured temperatures over time; and if the changes in the measured temperatures exceed a threshold, then respond to the changes in the measured temperatures exceeding the threshold by notifying a human user that the electronic shower system needs maintenance.

9. The electronic shower system of claim 8, wherein the second thermistor is positioned in the environment to measure ambient air temperature.

10. The electronic shower system of claim 8, wherein the second thermistor is positioned on a circuit board and in thermal communication with the fluid passageway.

11. The electronic shower system of claim 8, wherein the second thermistor is extended at least partially within the fluid passageway.

12. The electronic shower system of claim 8, wherein the controller is configured to analyze the received temperature measurement data from the first thermistor to determine changes in temperature measurements from the first thermistor over time, and analyze the received temperature measurement data from the second thermistor to determine changes in temperature measurements from the second thermistor over time.

13. The electronic shower system of claim 8, wherein the electronic controller is configured to analyze the received temperature measurement data to determine changes in differences between temperature measurements from the first thermistor and the second thermistor over time.

14. The electronic shower system of claim 1, wherein the second thermistor is positioned on a circuit board, the system further comprising a third thermistor extended at least partially within the fluid passageway, the controller being in electrical communication with the third thermistor and configured to receive temperature measurement data from the third thermistor.

15. A method of operating an electronic shower system, the method comprising the steps of: providing an electronically operable valve including a valve body defining a fluid passageway; taking first temperature measurements of a temperature of fluid passing through the fluid passageway at a first location; taking second temperature measurements of the electronic shower system at a second location spaced from the first location; operating the valve dependent upon the first temperature measurements; analyzing the first temperature measurements and the second temperature measurements to determine a presence of an anomaly; and mitigating the anomaly.

16. The method of claim 15, wherein the step of taking second temperature measurements includes measuring ambient air temperature.

17. The method of claim 15, wherein the step of taking second temperature measurements includes measuring temperature on a circuit board that is in thermal communication with the fluid passageway.

18. The method of claim 15, wherein the step of taking second temperature measurements includes measuring temperature in the fluid passageway.

19. The method of claim 15, comprising the further step of determining the presence of an anomaly based on differences in temperature measurements over time.

20. The method of claim 15, wherein the step of taking second temperature measurements includes measuring temperature on a circuit board, the method further comprising taking third temperature measurements within the fluid passageway at a third location spaced from the first location, the analyzing step comprising analyzing the third temperature measurements to determine the presence of the anomaly.

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