Description:TECHNICAL FIELD
[0001] The present disclosure generally relates to a flow sensor for determining a rate of flow of a fluid. In particular, the present disclosure relates to a flow sensor with a flexible element for determining a rate of flow of a fluid in a channel.

BACKGROUND
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] In a channel adapted for flow of liquids, such as oils, fuel, gas, etc., it is important to measure a flow rate of the fluid in order to determine a volume of the fluid passing through the channel at a given time. Further, especially in cases of combustible gases, there are limitations such as an amount of electricity that may be permissible in a vicinity of the channel.
[0004] Most conventional sensors used for determining flow rate of the gases are expensive and complex, resulting in high cost of maintenance.
[0005] There is, therefore, a requirement in the art for a means to determine fluid flow rate in a channel that is accurate, and economical.

OBJECTS OF INVENTION
[0006] An object of the present invention is to provide a flow sensor to determine a rate of flow of a fluid in a channel.
[0007] Another object of the present invention is to provide a flow sensor that is accurate.
[0008] Another object of the present invention is to provide a flow sensor that is economical.
[0009] Another object of the present invention is to provide a flow sensor that is easy to maintain.

SUMMARY
[0010] The present disclosure generally relates to a flow sensor for determining a rate of flow of a fluid. In particular, the present disclosure relates to a flow sensor with a flexible element for determining a rate of flow of a fluid in a channel.
[0011] In an aspect, the present disclosure provides a flow sensor including a flow sensor housing. The flow sensor further includes a flexible PCB positioned in the housing and adapted in a fluid flow path. The flow sensor further includes a magnet and a strain gauge positioned in the flow sensor housing such that current is supplied to the flexible PCB to maintain a first position of the flexible PCB that is measured by the strain gauge. Further the first position is a function of a distance of the flexible PCB from the magnet. Furthermore, the output flow rate of fluid is a function of supplied current.
[0012] In some embodiments, the flow sensor housing enables measurement of flow rate of any or a combination of gas and liquid.
[0013] In some embodiments, the strain gauge is inbuilt in the flexible PCB.
[0014] In some embodiments, the current is supplied through an electronic control unit including an electrical power supply unit, a current sensor, and a controller to maintain constant current supply.
[0015] In some embodiments, the power supply unit optionally includes an analog to digital converter to convert current into digital data, and wherein the power supply unit is operatively coupled with body of the flow sensor.
[0016] In some embodiments, the flow sensor enables determination of any or a combination of, strain gauge electrical resistance vs deflection, and current vs flow rate mapping.
[0017] In some embodiments, the output flow rate is processed along with one or more compensation factors to arrive at final flow rate of the fluid.
[0018] In some embodiments, the magnet is mounted in the flow stream inside the flow sensor and in proximity of the flexible PCB, and wherein north and south poles of the magnet enable the flexible PCB to be in the first position with respect to the magnet. When the fluid passes through the sensor, it applies pressure on the flexible PCB and tries to bend it, which is prevented by supplying the current to the flexible PCB such that the flexible PCB is in the first position.
[0019] In some embodiments, as the flow rate of the fluid increases, bending of the flexible PCB is controlled using the controller of power supply unit by increasing the current to maintain the first position of the flexible PCB. The strain gauge is connected to the controller to determine if the flexible PCB is in the first position.
[0020] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF DRAWINGS
[0021] The accompanying drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.
[0022] FIGs. 1A and 1B illustrate schematic front view and side view representations, respectively, of a flow sensor disposed in a channel adapted for flow of a fluid therethrough, according to an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0023] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such details as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0024] In an aspect, the present disclosure provides a flow sensor including a flow sensor housing. The flow sensor further includes a flexible PCB positioned in the housing and adapted in a fluid flow path. The flow sensor further includes a magnet and a strain gauge positioned in the flow sensor housing such that current is supplied to the flexible PCB to maintain a first position of the flexible PCB that is measured by the strain gauge. Further the first position is a function of a distance of the flexible PCB from the magnet. Furthermore, the output flow rate of fluid is a function of supplied current.
[0025] In some embodiments, the flow sensor housing enables measurement of flow rate of any or a combination of gas and liquid.
[0026] In some embodiments, the strain gauge is inbuilt in the flexible PCB.
[0027] In some embodiments, the current is supplied through an electronic control unit including an electrical power supply unit, a current sensor, and a controller to maintain constant current supply.
[0028] In some embodiments, the power supply unit optionally includes an analog to digital converter to convert current into digital data, and wherein the power supply unit is operatively coupled with body of the flow sensor.
[0029] In some embodiments, the flow sensor enables determination of any or a combination of, strain gauge electrical resistance versus deflection, and current vs flow rate mapping.
[0030] In some embodiments, the output flow rate is processed along with one or more compensation factors to arrive at final flow rate of the fluid.
[0031] In some embodiments, the magnet is mounted in the flow stream inside the flow sensor and in proximity of the flexible PCB, and wherein north and south poles of the magnet enable the flexible PCB to be in the first position with respect to the magnet. When the fluid passes through the sensor, it applies pressure on the flexible PCB and tries to bend it, which is prevented by supplying the current to the flexible PCB such that the flexible PCB is in the first position.
[0032] In some embodiments, as the flow rate of the fluid increases, bending of the flexible PCB is controlled using the controller of power supply unit by increasing the current to maintain the first position of the flexible PCB. The strain gauge is connected to the controller to determine if the flexible PCB is in the first position.
[0033] FIGs. 1A and 1B illustrate schematic front view and side view representations, respectively, of a flow sensor 100 disposed in a channel 190 adapted for flow of a fluid therethrough, according to an embodiment of the present disclosure. The channel 190 may have any cross-section, such as, without limitations, circular, semi-circular, and polygonal. The channel 190 may be covered or may be open. In the illustrated embodiment of FIG. 1A, the channel 190 has a circular cross-section. The channel 190 may be adapted to allow a fluid to flow therethrough. The fluid may be a liquid, a gas, or a combination thereof.
[0034] The flow sensor 100 may be configured with the channel 190. The flow sensor 100 includes a housing 102. The housing 102 includes a flexible printed circuit board (PCB) 104 that is fixedly coupled to a wall of the channel 190 via a stem 106. The PCB 104 is adapted to be positioned in a path of the flow of the fluid. The PCB 104 includes a coil. The stem 106 may be flexible. The stem 106 may further include a strain gauge 108 configured on the stem 106. The strain gauge 108 may be configured to detect a degree of flex in the stem 106, which may be indicative of a displacement of the PCB 104 due to a force of flow of the fluid. The stem 106 may further be coupled to an electronic control unit (ECU) 150. The ECU 150 may include components configured to operate the flow sensor 100. The stem 106 may further include components that allow for operative coupling of the PCB 104 and the strain gauge 108 with the ECU 150.
[0035] The housing 102 further includes a rigid structure 120 fixedly coupled to the wall of the channel 190, at a predetermined distance from the stem 106 and PCB 104. The rigid structure 120 is provided with a magnet 122 positioned such that, in a default state, the magnet 122 is at a fixed distance from the PCB 104, and the PCB 104 is in a first position. The first position of the PCB 104 is indicative of a predetermined distance of the PCB 104 from the magnet 122 in the default state. In an exemplary embodiment, the first position of the PCB 104 may be an upright position, as illustrated in FIG. 1B.
[0036] Further, the magnet 122 is positioned such that its polarity is fixed with respect to the PCB 104. Furthermore, the north and south poles of the magnet 122 enable the PCB 104 to be attracted and/or repelled towards the magnet 122 and remain in the first position. When the fluid passes through the flow sensor 100, the fluid applies pressure on the PCB 104 and tries to bend it. The force applied on the PCB 104 by the fluid may be measured by the strain gauge 108. A current is supplied to the PCB 104, such that the PCB 104 is maintained in the first position.
[0037] The ECU 150 may be configured to supply a current to the PCB 104, such that the coil in the PCB 104 is energized, thereby creating a magnetic field within the PCB 104. Based on the amount and polarity of current supplied, the PCB 104 may be attracted or repelled from the magnet 122. The ECU 150 may include a current sensor 152, a power supply unit 154, and a controller 156.
[0038] When the fluid in the channel 190 passes through the flow sensor 100, it applies pressure on the PCB 104 and tries to bend it. The bending may be prevented by supplying, by the power supply unit 154, a current to PCB 104, such that the PCB 104 is in the first position. As the flow rate of the fluid varies, the pressure of fluid on the PCB 104 correspondingly varies, and a current required to maintain the first position of the PCB 104 also correspondingly varies.
[0039] In the illustrated embodiment of FIG. 1B, as the fluid flows, a force is applied on the PCB 104 to move the PCB 104 away from the magnet 122. Thus, the current supplied is such as to generate an attractive force between the PCB 104 and the magnet 122.
[0040] However, in some other embodiments, the direction of the fluid flow may be so as to move the PCB 104 towards the magnet 122. As a result, the current supplied to the PCB 104 may be such as to generate a repulsive force between the PCB 104 and the magnet 122.
[0041] The current being supplied to the PCB 104 in order to maintain its first position is measured by the current sensor 152, and a degree of flex of the PCB 104 is measured by the strain gauge 108. The controller 156 is configured to receive the data from the current sensor 152 and the strain gauge 108. The controller 156 is configured to vary the current supplied to the PCB 104 in order to maintain the PCB 104 in the first position.
[0042] The controller 156 is configured to determine a rate of flow of the fluid in the channel 190 based on the current supplied to the PCB 104. Thus, the flow sensor 100 enables measurement of a rate of flow of the fluid through the channel 190.
[0043] In some embodiments, the controller 156 is configured to process an output flow rate of the fluid in the channel 190 along with one or more compensation factors to arrive at a final flow rate of the fluid in the channel 190.
[0044] It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the spirit of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refer to at least one of something selected from the group consisting of A, B, C ….and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc. The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the appended claims.
[0045] While the foregoing describes various embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

ADVANTAGES OF INVENTION
[0046] The present invention provides a flow sensor to determine a rate of flow of a fluid in a channel.
[0047] The present invention provides a flow sensor that is accurate.
[0048] The present invention provides a flow sensor that is economical.
[0049] The present invention provides a flow sensor that is easy to maintain.
, Claims:1. A flow sensor (100) comprising:
a flow sensor housing (102);
a flexible PCB (104) positioned in the housing (102) and adapted in a fluid flow path; and
a magnet (122) and a strain gauge (108) positioned in the flow sensor housing (102) such that current is supplied to the flexible PCB (104) to maintain a first position of the flexible PCB (104) that is measured by the strain gauge (108), wherein the first position is a function of a distance of the flexible PCB (104) from the magnet (122), and wherein output flow rate of fluid is a function of supplied current.

2. The flow sensor (100) as claimed in claim 1, wherein the flow sensor housing (102) enables measurement of flow rate of any or a combination of gas and liquid.

3. The flow sensor (100) as claimed in claim 1, wherein the strain gauge (108) is inbuilt in the flexible PCB (104).

4. The flow sensor (100) as claimed in claim 1, wherein the flow sensor (100) enables determination of any or a combination of, strain gauge electrical resistance vs deflection, and current vs flow rate mapping.

5. The flow sensor (100) as claimed in claim 1, wherein the output flow rate is processed along with one or more compensation factors to arrive at final flow rate of the fluid.

6. The flow sensor (100) as claimed in claim 1, wherein the current is supplied through an electronic control unit (150) comprising an electrical power supply unit (154), a current sensor (152), and a controller (156) to maintain constant current supply.

7. The flow sensor (100) as claimed in claim 6, wherein the power supply unit (154) optionally comprises an analog to digital converter to convert current into digital data, and wherein the power supply unit (154) is operatively coupled with body of the flow sensor (100).

8. The flow sensor (100) as claimed in claim 6, wherein the magnet (122) is mounted in the flow stream inside the flow sensor (100) and in proximity of the flexible PCB (104), and wherein north and south poles of the magnet (122) enable the flexible PCB (104) to be in the first position with respect to the magnet (122), and wherein when the fluid passes through the sensor (100), it applies pressure on the flexible PCB (104) and tries to bend it, which is prevented by supplying the current to the flexible PCB (104) such that the flexible PCB (104) is in the first position.

9. The flow sensor (100) as claimed in claim 6, wherein as the flow rate of the fluid increases, bending of the flexible PCB (104) is controlled using the controller (156) of power supply unit (154) by increasing the current to maintain the first position of the flexible PCB (104), and wherein the strain gauge (108) is connected to the controller (156) to determine if the flexible PCB (104) is in the first position.