Systems and assemblies associated with flexible printed circuit boards having coils printed thereon for indicating the position of a movable member - Patent Application 20070122999

Abstract

An exemplary assembly includes a housing, a movable member configured to move within the housing, and a coil flexible printed circuit board (FPCB) wrapped around the housing, the coil FPCB including at least one excitation coil printed as a conductive track on the coil FPCB, the excitation coil configured to generate a magnetic field when a current is supplied to the conductive track, and at least one detection coil printed as a respective conductive track on the coil FPCB, the magnetic field generated by the excitation coil configured to induce respective currents in the at least one detection coil, and movement of the movable member within the housing changes a parameter associated with the respective currents, thereby indicating the position of the movable member.

Description

[Background technology]

[0001] Many applications involve moving members such as pistons, spools, poppets, rotors, etc. Control of such moving members typically involves sensors that detect the position (linear and / or rotational) of the moving member and provide sensor information indicative of such position to a controller.

[0002] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Provisional Patent Application No. 63 / 483,795, filed February 8, 2023, the entire contents of which are incorporated herein by reference as if fully set forth.

[0003] For example, a controller can control the movement of a movable member based on sensor information, such as by implementing a feedback control loop. In one example, the controller may infer another parameter, such as flow through a valve, based on the position of the movable member. In another example, the controller may determine that the movable member is in a safe position based on the sensor information. Therefore, in such applications, it is important to have sensors that provide accurate position information.

[0004] Multiple position sensing technologies exist. However, providing accurate sensor information using conventional techniques typically results in expensive configurations that are difficult to manufacture, have large physical size, and require tight tolerances. It would therefore be desirable to have a sensor configuration that alleviates these problems. It is with respect to these and other considerations that the present disclosure is presented. Summary of the Invention

[0005] In the examples described herein, systems and assemblies are disclosed that are associated with a flexible printed circuit board having a coil printed thereon to indicate the position of a movable member.

[0006] In a further example described herein, a flexible printed circuit board having coils printed thereon is wrapped around a housing or body within which a movable member is configured to move. The coils include at least one excitation coil and one sensing coil. The coils detect the position of the movable member as the movable member moves linearly or rotationally relative to the flexible printed circuit board.

[0007] The above summary is illustrative only and is not intended to be in any way limiting. These exemplary aspects, embodiments, and features, as well as other aspects, embodiments, and features, will become apparent by reference to the drawings and the following detailed description.

[0008] The novel features believed distinctive to the embodiments are set forth in the appended claims. However, these embodiments, as well as their preferred modes of use, other objects and explanations, will best be understood by reference to the following detailed description of the embodiments of the present disclosure, read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a coil flexible printed circuit board according to an exemplary embodiment. [Figure 2] 2 is a perspective view of the coil flexible printed circuit board of FIG. 1 coupled with a handle flexible printed circuit board according to an exemplary embodiment. [Figure 3] 3 is a perspective view of the coil flexible printed circuit board and the handle flexible printed circuit board of FIG. 2 in a configuration wrapped about a transverse axis according to an exemplary embodiment. [Figure 4] FIG. 1 illustrates an assembly of a coil flexible printed circuit board and a handle flexible printed circuit board wrapped around a cylindrical member within which a movable member is configured for linear movement, according to one exemplary embodiment. [Figure 5]FIG. 1 is a perspective view of a coil flexible printed circuit board for detecting the angular position of a movable member, according to an exemplary embodiment. [Figure 6] 6 is a perspective view of the coil flexible printed circuit board of FIG. 5 coupled with a handle flexible printed circuit board according to an exemplary embodiment. [Figure 7] 7 illustrates an assembly of the flexible printed circuit board and the handle flexible printed circuit board of FIG. 6 wrapped around a cylindrical member within which a movable member is configured for rotational movement, according to one exemplary embodiment. [Figure 8] FIG. 1 is a cross-sectional side view of a valve according to an exemplary embodiment. [Figure 9] 1 is a flowchart of a method for forming and operating an assembly, according to an example embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Devices or assemblies such as valves, actuators, electric motors, etc. have moving members such as spools, pistons, poppets, rotors, etc. Such assemblies may involve the use of position sensors to provide information indicative of the position of the moving member and allow control of the position of the moving member to indicate fluid flow through the valve, to indicate safety information, etc.

[0011] Various types of position sensors can be used to indicate the position of the movable member. Exemplary linear position sensors include linear potentiometers, linear magnetic Hall effect sensors, magnetostrictive linear position sensors, incremental linear encoders, linear inductive position sensors, linear variable differential transformer (LVDT) sensors, draw wire sensors, eddy current sensors, capacitive position sensors, single point laser sensors, fiber optic linear position sensors, rotary encoders, etc. Exemplary rotary position sensors include rotary variable differential transformer (RVDT) sensors.

[0012] These prior art technologies have drawbacks, for example, LVDTs and RVDTs require large amounts of wire to be wound to form multiple coils, making them expensive, complex, difficult to manufacture, and disadvantageous due to their large physical size and tight tolerances.

[0013] Disclosed herein is a flexible printed circuit board (FPCB) that can be wrapped around a housing or body (e.g., a cylindrical member) having a cavity therein configured for linear or rotational movement of a movable member. The FPCB has a plurality of coils formed as looped (e.g., spiral) conductive traces or tracks printed on the FPCB. The conductive tracks can be etched from one or more sheet layers of copper laminated onto and / or between sheet layers of a non-conductive substrate of the FPCB.

[0014] The plurality of coils includes at least one excitation coil and one detection coil. The excitation coil, by way of example, generates a magnetic field that is sensed by the detection coil. The movable member includes at least a portion constructed of a magnetic material. As the movable member moves relative to the FPCB, the magnetic field sensed by the detection coil changes, indicating the position of the movable member.

[0015] In one example, the coil-printed FPCB may be coupled to another FPCB (e.g., a process FPCB). In one example, the process FPCB is configured with a polygonal shape having flat surfaces that mechanically support and electrically connect electronic components (e.g., microprocessors, integrated chips (ICs), capacitors, resistors, etc.). Such components are typically soldered onto the process FPCB to electrically connect and mechanically secure them. This allows the process FPCB to incorporate regulation and detection circuitry and to be electrically coupled to the coil of the coil-printed FPCB via conductive traces.

[0016] In one example, if the linear movement of a moving part is to be measured, each coil can extend linearly along the length of the FPCB. In another example, if the rotational position of a moving part is to be measured, multiple separate sensing coils can be disposed on the FPCB. FPCBs can be used in any application, such as valves, actuators (hydraulic cylinders, hydraulic motors, electric actuators), electric motors, etc.

[0017] 1 is a perspective view of a coil FPCB 100 according to an exemplary embodiment. Printed circuit boards (PCBs) are used to minimize the size and complexity of wiring circuits. The wires in a normal circuit are transformed into conductive tracks in the PCB. Like wires, conductive tracks also have their own resistance, so the maximum current that can flow through a conductive track is determined by the width of the conductive track.

[0018] PCBs can be rigid or flexible. FPCBs, also known as flexible printed circuits (FPCs), have different properties than rigid circuit boards. Unlike rigid PCBs, FPCBs are made from materials that can bend, improving their resistance to vibration and movement and allowing them to fit around tight spaces and objects. Additionally, the compact design of FPCBs allows for significant package weight reductions. Another advantage of FPCBs is that they have fewer connection points, eliminating the poor connections common with solder joints.

[0019] In one example, the coil FPCB 100 is configured as a bendable printed circuit made of a flexible film having a printed coil pattern arrangement using a flexible substrate for the coil FPCB 100. In particular, in the exemplary embodiment of FIG. 1, the coil FPCB 100 can have an excitation coil 102, a first detection coil 104, and a second detection coil 106 printed thereon. More or fewer coils can be used. For example, while one excitation coil is shown, more excitation coils can be used based on the range of motion of the movable member.

[0020] The excitation coil 102 is positioned between (or is the central coil relative to) the first and second detector coils 104, 106. The excitation coil 102 is formed as a conductive track 108 that loops along the coil FPCB 100. In particular, the conductive track 108 can have a starting point 110, and the conductive track 108 extends laterally, longitudinally along the length of the coil FPCB 100, laterally, and then longitudinally again to form a spiral along the length of the coil FPCB 100. In the exemplary embodiment of FIG. 1 , the excitation coil 102 is formed as a rectangular spiral conductive track. However, in other examples, the excitation coil spiral may have a different geometric shape (e.g., an oval shape). The term “spiral” is used herein to indicate that the conductive track spirals as a continuous, gradually widening (or narrowing) line or curve across the plane of the coil FPCB 100.

[0021] Similarly, the first sense coil 104 is formed as a helical conductive track (e.g., a rectangular spiral) disposed laterally of the excitation coil 102 on a first side of the excitation coil 102. The second sense coil 106 is also formed as a helical conductive track (e.g., a rectangular spiral) disposed laterally of the excitation coil 102 on a second side of the excitation coil 102 opposite the first side on which the first sense coil 104 is disposed. Furthermore, as will be described in more detail below with respect to FIG. 3, each of the coils (e.g., the excitation coil 102 and the sense coils 104, 106) may include multiple layers of conductive tracks stacked on top of each other.

[0022] In one example, a process FPCB may be coupled to the coil FPCB 100. The process FPCB may have conditioning and sensing circuitry that controls the current supplied to the excitation coil 102, and conditions and processes the current / voltage / energy induced in the sensing coils 104, 106 to indicate the position of the movable member.

[0023] 2 is a perspective view of coil FPCB 100 coupled to process FPCB 200, according to one exemplary embodiment. Process FPCB 200 is connected to coil FPCB 100 via bridge 201, which connects excitation coil 102 and sensing coils 104, 106 via conductive tracks to the electronic components of the regulation and sensing circuitry attached to process FPCB 200.

[0024] In one example, the process FPCB 200 includes multiple segments such that when the coil FPCB 100 is wrapped around an object, the process FPCB 200, when wrapped around the object, forms a polygonal shape with flat sides. For example, as shown in FIG. 2, the process FPCB 200 includes segments 202, 204, 206, 208, 210, and 212. Thus, when wrapped, the process FPCB 200 forms a hexagon with six flat sides that contain the electronic components of the regulation and sensing circuitry (e.g., digital signal processors, microprocessors, integrated circuits, capacitors, resistors, etc.).

[0025] This configuration may be advantageous in some applications. For example, the cartridge valve may have a hexagonal nut or housing that allows the process FPCB 200 to be easily wrapped around it due to the corresponding polygonal configuration of the process FPCB 200. However, in other examples, the regulation and sensing circuitry may be located externally (e.g., in a controller in communication with the coil FPCB 100) rather than on the FPCB coupled to the coil FPCB 100.

[0026] 3 is a perspective view of a coil FPCB 100 and a process FPCB 200 in a configuration wound about a transverse axis 300, according to one exemplary embodiment. In FIG. 3, the substrate of the coil FPCB 100 is not shown, but only the coil, to reduce visual clutter. As shown, the excitation coil 102 is centered between a pair of conductive tracks of the sense coil, which are spaced symmetrically with respect to the conductive tracks of the excitation coil 102.

[0027] 1-3, the conductive track of the excitation coil 102 is thicker than the conductive tracks of the sense coils 104, 106. By way of example, the conductive track of the excitation coil 102 may have a thickness between 4 and 40 thousandths of an inch. Thicker tracks may accommodate higher current levels and, for example, maintain lower electrical resistance. By way of example, the conductive track of the excitation coil 102 may be different (e.g., in thickness, width, number of turns, etc.) from the conductive tracks of the sense coils 104, 106.

[0028] As shown in FIG. 3 , when wound around a transverse axis 300, the processed FPCB 200 forms a hexagon with six flat sides that facilitates the mounting of electronic components (e.g., ICs, capacitors, resistors, etc.). Additionally, each coil can have a depth of multiple layers (e.g., forming multiple layers along the depth of the coil FPCB 100). For example, the conductive tracks of the first sense coil 104 form four layers (first layer 302, second layer 304, third layer 306, and fourth layer 308). More or fewer layers can be used (e.g., six or ten layers). The conductive tracks of the excitation coil 102 and second sense coil 106 can also form corresponding layers as shown in FIG. 3 . This configuration may advantageously increase the inductance of the coils, as discussed in more detail below.

[0029] 4 illustrates an assembly 400 of a coil FPCB 100 and a process FPCB 200 wound around a housing 402, with a movable member 404 configured for linear movement within the housing 402, according to one exemplary embodiment. In FIG. 4, the details of the conductive tracks forming the coil formed on the coil FPCB 100 are not shown to reduce visual clutter in the drawing.

[0030] The housing 402 may be any structure or body within which the movable member 404 can move. The housing 402 is configured to facilitate winding of the coil FPCB 100 and the process FPCB 200. For example, the housing 402 may be any enclosure for a valve or actuator, and the coil FPCB 100 and the process FPCB 200 may be disposed on the interior or exterior surface of such an enclosure. The housing 402 is shown as a cylindrical member for illustrative purposes only. In other exemplary embodiments, the housing 402 may have other geometric shapes.

[0031] 3-4, in operation, the conductive tracks of the excitation coil 102 can be excited, by way of example, by an alternating current (AC) or impulse drive of suitable amplitude and frequency, known as primary excitation. Impulse drive can include a buildup of current in the excitation coil 102, followed by a sudden release of the current, which can be repeated one or more times. Such primary excitation can be provided, for example, by the process FPCB 200 or by an external source.

[0032] The excitation signal causes the excitation coil 102 to generate a magnetic field, which induces a voltage in the sense coils 104, 106. A differential signal, such as a differential voltage, differential current, differential phase, or differential energy transfer between the sense coils 104, 106 (e.g., the difference between the voltage of the signal generated in the first sense coil 104 and the voltage of the signal generated in the second sense coil 106), is then sensed by the electronics of the processing FPCB 200. In other examples, current or energy may be sensed instead of voltage.

[0033] The movable member 404, or at least a portion thereof, is constructed of a magnetic material. Thus, linear movement of the movable member 404 within the housing 402 changes the voltage induced in the sensing coils 104, 106. In other words, the differential voltage between the sensing coils 104, 106 sensed by the process FPCB 200 varies with the axial position of the movable member 404 within the housing 402 and coil FPCB 100. This differential voltage is converted by suitable electronic circuitry in the process FPCB 200 into a direct current (DC) voltage or current indicative of the axial position of the movable member 404. For example, the DC voltage can be used by a controller of the assembly 400 to determine the position of the movable member 404.

[0034] The configuration of the coil FPCB 100 may provide several advantages over conventional sensing techniques. As previously described, the excitation coil 102 and the sensing coils 104, 106 are each formed as a conductive track that forms a longitudinal helical loop along the length of the coil FPCB 100. The coil FPCB 100 is then wrapped around the housing 402 and the movable member 404 on a transverse axis 300. The transverse axis 300 is the direction of axial movement of the movable member 404 within the housing 402 and the coil FPCB 100.

[0035] With this configuration, the strongest magnetic field lines of the magnetic field generated by excitation coil 102 are directed along axis 310 (shown in FIG. 3) perpendicular to lateral axis 300. This is in contrast to conventional LVDT configurations, which include coils formed from wire windings wrapped around a movable member to generate magnetic fields in lines parallel to the direction of motion of the movable member.

[0036] Additionally, forming the excitation coil 102 and sense coils 104, 106 as printed conductive tracks allows for precise coil geometry and configuration. For example, conductive tracks as thin as 0.003 inches can be printed onto the coil FPCB 100. This allows for more precise control of the generated magnetic field and induced voltage.

[0037] Additionally, because the coil FPCB 100 is thin and flexible as described above, it can be bent and wrapped around a small radius, which may be desirable in some applications involving tight spaces or complex shapes. Additionally, the coil FPCB 100 can be wrapped around the movable member 404 multiple times (e.g., two or more times, such as three or four times) (e.g., similar to a roll of tape wrapped around an object multiple times), advantageously increasing the inductance of the excitation coil 102 and the sense coils 104, 106.

[0038] In particular, copper conductive tracks with low resistance and high inductance are advantageous because (e.g., by making them thicker) the frequency of the induced voltage and therefore the differential voltage output from the sensing coils 104, 106 is reduced. Higher frequencies may require more costly conditioning and sensing circuitry in the processing FPCB 200 compared to lower frequencies. For example, lower frequency signals may advantageously reduce the amount of eddy currents and similar losses that can occur at higher frequencies. Furthermore, having conductive tracks formed in multiple layers (e.g., layers 302-308) as shown in FIG. 3 further increases the inductance of the coils, further reducing the frequency of the output voltage signals.

[0039] In an example, in applications involving a large stroke of the moving member 404, more sensing coils can be added laterally to increase the detection range of the moving member 404. In another example, the functions of the excitation coil 102 and the sensing coils 104, 106 can be reversed, such that the excitation coil 102 acts as a sensing coil while one or both of the sensing coils 104, 106 act as excitation coils. This allows for flexibility in the operation of the coil FPCB 100 in sensing the moving member in many configurations.

[0040] In one example, a cylindrical shield constructed of ferrite or other magnetic and / or electrical shielding material can be placed around the coil FPCB 100. Such a shield can focus the magnetic field lines inside the coil FPCB 100 or assembly 400 and prevent external magnetic field lines and other electrical noise from interfering with the signals generated by the sense coils 104, 106.

[0041] In one example, a temperature sensor may be integrated onto the coil FPCB 100 or process FPCB 200. The processing electronics of the process FPCB 200 can then use temperature sensor information from the temperature sensor to compensate for temperature variations by adjusting or calibrating the output signals from the sensing coils 104, 106. Having such a temperature sensor integrated onto the process FPCB 200 may reduce costs.

[0042] In one example, the processing FPCB 200 may further include a communication interface (e.g., an antenna) for communicating using various protocols such as Bluetooth, Wi-Fi, cellular communication protocols such as CDMA (e.g., 1xRTT or 1xEV-DO), WiMAX, LTE, IDEN, GSM, WIFI, HSPA, or any other wireless protocol, or any wired interface (e.g., serial, controller area network, Ethernet, etc.). In this manner, the processing FPCB 200 may communicate a signal indicative of the position of the movable member (e.g., movable member 404) to a controller, a remote computing device or server, the cloud, etc. The position-indicative signal may be, for example, an analog voltage signal (e.g., a DC voltage between 0 and 5) or a current signal (e.g., between 4 and 20 milliamps).

[0043] As an alternative or in addition to measuring the linear position of a moving part using an FPCB such as coil FPCB100, a similar arrangement can be used to measure the angle of rotation of a rotating object, such as the rotor of an electric motor. In this case, multiple smaller sensing coils can be placed alongside the excitation coil, one on each side of the excitation coil.

[0044] 5 is a perspective view of a coil FPCB 500 for detecting the angular position of a movable member, according to one exemplary embodiment. Coil FPCB 500 is similar to coil FPCB 100 in that it is flexible and bendable and can be wrapped around a movable (e.g., rotating) member.

[0045] For this reason, the coil FPCB 500 is also configured as a bendable printed circuit, constructed from a flexible film having a printed coil pattern arrangement using a flexible substrate for the coil FPCB 500. In particular, as shown in Figure 5, the coil FPCB 500 can have an excitation coil 502 similar to the excitation coil 102. However, rather than having a detection coil laterally disposed on one side of the excitation coil and another detection coil laterally disposed on the other side of the excitation coil, each side includes multiple smaller spiral or loop coils.

[0046] In particular, as shown in the exemplary embodiment of FIG. 5 , coil FPCB 500 includes a first plurality of sense coils 503 (such as sense coil 504 and sense coil 506) disposed laterally (e.g., on a first side of) excitation coil 502. Coil FPCB 500 may also include a second plurality of sense coils 507 (such as sense coil 508 and sense coil 510) disposed laterally (e.g., on a second side of excitation coil 502) opposite first plurality of sense coils 503. In the exemplary embodiment of FIG. 5 , by way of example, nine sense coils are disposed on each side of excitation coil 502. More or fewer excitation or sense coils may be used depending on the application and range of rotational motion.

[0047] In one example, the coil FPCB 500 may have holes (such as hole 512) on each side of the excitation coil 502, and the use of such holes allows for assembly (winding) of the detection coils directly stacked on top of each other.

[0048] In one example, each of the sensing coils of the plurality of sensing coils 503, 507 is formed as a spiral conductive track (e.g., a rectangular spiral). Similar to the sensing coils 104, 106, each of the plurality of sensing coils 503, 507 can include multiple layers of conductive tracks stacked on top of each other (similar to the configuration shown in FIG. 3). Additionally, a processing FPCB similar to processing FPCB 200 can be coupled to coil FPCB 500.

[0049] 6 is a perspective view of a coil FPCB 500 coupled to a process FPCB 600, according to one exemplary embodiment, which is connected to the coil FPCB 500 via a bridge 601 that connects an excitation coil 502 and multiple sensing coils 503, 507 via conductive tracks to the electronic components of the conditioning and sensing circuitry attached to the process FPCB 600.

[0050] In one example, the process FPCB 600 includes multiple segments such that when the coil FPCB 500 is wrapped around an object, the process FPCB 600, along with the coil FPCB 500, forms a polygonal shape with flat sides. For example, as shown in FIG. 6, the process FPCB 600 includes segments 602, 604, 606, 608, 610, and 612. Thus, when the process FPCB 600 is wrapped, it forms a hexagon with six flat sides that contain the electronic components of the regulation and sensing circuitry (e.g., digital signal processors, microprocessors, integrated circuits, capacitors, resistors, etc.). This configuration may be advantageous in some applications, as discussed above.

[0051] 7 illustrates an assembly 700 of a coil FPCB 500 and a process FPCB 600 wound around a housing 702, with a movable member 704 configured for rotational movement within the housing 702, according to one exemplary embodiment. In FIG. 7, the details of the conductive tracks forming the coil formed on the coil FPCB 500 are not shown to reduce visual clutter in the drawing.

[0052] The housing 702 is configured as any structure or body within which the movable member 704 can rotate. The housing 702 is configured to facilitate winding of the coil FPCB 500 and the process FPCB 600. For example, the housing 702 can be the stator of an electric motor, with the coil FPCB 500 and the process FPCB 600 disposed on its interior or exterior surface. The housing 702 is shown as a cylindrical member for illustrative purposes only. In other exemplary embodiments, the housing 702 can have other geometric shapes.

[0053] The movable member 704 is not symmetrical along an axis 705 (the longitudinal axis of the movable member 704, which coincides with the transverse axis of the coil FPCB 500). Rather, the movable member 704 includes a notch 706 constructed of a magnetic material.

[0054] In operation, the conductive track of the excitation coil 502 can be excited by an AC signal or impulse drive of appropriate amplitude and frequency, known as primary excitation, from, for example, the process FPCB 600 or an external source. Such excitation signal results in the generation of a magnetic field, which induces a voltage in the plurality of sense coils 503, 507. The differential voltage between the plurality of sense coils 503, 507 is detected by the electronics of the process FPCB 600. In other examples, current or energy may be sensed instead of voltage.

[0055] As the movable member 704 rotates within the housing 702, the voltage induced in the plurality of sensing coils 503, 507 changes due to the asymmetry caused by the notch 706. In other words, the differential voltage between the plurality of sensing coils 503, 507 sensed by the process FPCB 600 varies with the angular position of the movable member 704 within the housing 702 and coil FPCB 500. This differential voltage is converted by suitable electronic circuitry in the process FPCB 600 into a DC voltage or current indicative of the rotational position of the movable member 704. For example, the DC voltage can be used by a controller of the assembly 700 to determine the angular position of the movable member 704.

[0056] The configuration of coil FPCB500 and process FPCB600 may provide the same advantages as those described above with respect to coil FPCB100 and process FPCB200. Additionally, the coil configuration of coil FPCB500 can be combined with the coil configuration of coil FPCB100, and the combined coil FPCB can measure both the linear and rotational position of a moving member in applications where the moving member has both linear and rotational movement.

[0057] The assemblies 400, 700 can be used in many applications for measuring the linear and / or rotational position of a movable member. A valve will now be described as an example only. It will be understood that the configurations described above with respect to Figures 1-7 can be used in any other application where it is desirable to measure the linear and / or axial position of a movable member.

[0058] 8 is a cross-sectional side view of an exemplary embodiment of a valve 800. Valve 800 may be inserted or threaded into a manifold having ports corresponding to those of valve 800, described below, such that such a manifold can fluidly couple valve 800 to other components of a hydraulic system.

[0059] Valve 800 includes a housing 802 having a longitudinal cylindrical cavity therein. Valve 800 also includes a sleeve 804 at least partially disposed within the longitudinal cylindrical cavity of housing 802 and received in a distal end of housing 802. Sleeve 804 is rigidly or fixedly coupled to housing 802. For example, sleeve 804 can be threadedly coupled to housing 802 by threads 806.

[0060] Valve 800 also includes a nosepiece 808 received in the distal end of sleeve 804. Nosepiece 808 is coupled to sleeve 804 via a retaining ring 809 such that nosepiece 808 can "float" relative to sleeve 804. In this manner, nosepiece 808 can move to compensate for any tolerances in the manifold cavity in which valve 800 is disposed.

[0061] Valve 800 includes a first port 810 at the nose or distal end of nosepiece 808 and sleeve 804. Valve 800 also includes a second port 812 disposed laterally in sleeve 804. Second port 812 may include a set of cross-holes (such as cross-hole 814) disposed in a circular or circumferential array around sleeve 804. As used herein, the term "hole" is used generally to refer to a hollow location (e.g., a cavity), for example, in a solid body or surface. The term "cross-hole" refers to a hole that crosses the path of another hole, cavity, or channel.

[0062] Valve 800 also includes a third port 816. Third port 816 may be referred to as a pilot port. Third port 816 may include one or more cross-holes, which may be referred to as pilot signal cross-holes (such as pilot signal cross-hole 817), disposed in housing 802. As described below, pilot signal cross-hole 817 is configured to receive a pilot fluid signal to close valve 800 and prevent fluid flow between first port 810 and second port 812.

[0063] Sleeve 804 includes a respective longitudinal cylindrical cavity therein. Valve 800 includes a poppet 818 at least partially disposed in the longitudinal cylindrical cavity of sleeve 804 and slidably received therein. Throughout this specification, the term "slidably received" is used to indicate that a first component (e.g., poppet 818) is positioned relative to a second component (e.g., sleeve 804) with sufficient clearance to permit proximal and distal movement of the first component relative to the second component.

[0064] When valve 800 is closed, the distal end of poppet 818 rests against poppet seat 820 formed by the inner surface of sleeve 804. In Figure 1, valve 800 is shown with poppet 818 resting against poppet seat 820, thereby blocking the flow path between first port 810 and second port 812. Additionally, the nose end of poppet 818 extends distally beyond poppet seat 820 and overlaps the inner surface of sleeve 804, further blocking fluid flow. Throughout this specification, the term "blocking" is used to indicate substantially preventing fluid flow except for a minimal or leakage flow of, for example, drops per minute.

[0065] Valve 800 further includes a piston 822 adjacent to poppet 818. Piston 822 is slidably received within housing 802.

[0066] Valve 800 also includes a spring 824 disposed in a spring chamber 825 within housing 802. A proximal end of spring 824 abuts the inner surface of housing 802, while a distal end of spring 824 abuts a flange portion of piston 822. In this configuration, spring 824 biases piston 822 toward poppet 818, causing poppet 818 and piston 822 to interact and move together. In one example, spring 824 is configured as a soft spring. As an illustrative example, spring 824 can be a 25 pounds per square inch (psi) spring.

[0067] When fluid is supplied to first port 810, such fluid applies a proximal fluid force to poppet 818 and piston 822 against spring 824. Similarly, when fluid is supplied to second port 812, such fluid flows through undercut 826 formed in sleeve 804 and cross-hole 828 formed in sleeve 804 to annular groove 830 formed in poppet 818. The fluid in annular groove 830 applies a proximal fluid force to poppet 818 and piston 822 against spring 824.

[0068] When third port 816 receives a pilot fluid signal, the pilot fluid signal is transmitted through pilot signal cross-hole 817 to spring chamber 825. Such pilot fluid signal, in combination with the biasing force of spring 824, applies a distal fluid force to piston 822 and poppet 818.

[0069] 8, piston 822 is partially hollow and has a channel in which movable member 832 is received. For example, movable member 832 is press-fit into piston 822 so that piston 822 and movable member 832 move together. In particular, the inner diameter of certain portions of piston 822 can be slightly smaller than the outer diameter of movable member 832, allowing movable member 832 to be press-fit into piston 822 when pressed into the channel of piston 822.

[0070] In one example, piston 822 has a side hole (such as hole 834). A tool can be inserted through hole 834 to deform or swage movable member 832, coupling movable member 832 to piston 822 such that axial movement of piston 822 moves movable member 832 with it. When spring 824 presses piston 822 against poppet 818, movable member 832 is indirectly coupled to poppet 818 such that poppet 818 and movable member 832 move together. Movable member 832 is at least partially constructed of a magnetic material and acts as a magnetic target for a position sensor, as described below.

[0071] Valve 800 further includes a position sensor assembly 836. Position sensor assembly 836 includes a sensor housing 838 that can be threadedly coupled to the exterior surface of housing 802 by threads 840. A proximal housing portion 842 of housing 802 extends into sensor housing 838 and has a channel 844 that receives a portion of movable member 832 to allow linear movement therethrough.

[0072] In one example, the position sensor assembly 836 may further include a sensor carrier 846, which is a hollow cylindrical component mounted around the proximal housing portion 842. The sensor carrier 846 may be made of a non-magnetic material such as plastic or metal. The coil FPCB100 and the process FPCB200 are wound around the sensor carrier 846. However, in other exemplary embodiments, the coil FPCB100 and the process FPCB200 may be mounted directly to the proximal housing portion 842.

[0073] A cable 848 connects or electrically couples the electronics of process FPCB 200 to conductive pins 850, which are coupled to an electrical connector 852. A controller (not shown) can also be electrically connected to valve 800 via a plug and into electrical connector 852, allowing the controller to send commands to the process FPCB of excitation coil 102 and also receive processed output signals generated by process FPCB 200.

[0074] In an example where process FPCB 200 is not coupled to coil FPCB 100 but is mounted inside valve 800, the process FPCB components are mounted external to valve 800. In this example, coil FPCB 100 receives an excitation signal via electrical connector 852 and provides an output signal to external circuitry via electrical connector 852.

[0075] The position sensor assembly 836 is configured to provide sensor information indicative of the position of the movable member 832, which in turn indicates the axial position of the piston 822 and poppet 818. As such, the movable member 832 operates as the movable member 404 described above with respect to FIG. 4. In particular, as the movable member 832 moves axially, the magnetic field generated by the excitation coil 102 is disturbed, causing the voltage / current induced in the sense coils 104, 106 to change based on the axial position of the movable member 832. In this manner, the signals generated by the sense coils 104, 106 of the coil FPCB 100 are indicative of the change in the magnetic field, which can be used by the processing FPCB 200 or an external controller to determine the position of the movable member 832.

[0076] In one example, for calibration, the axial position of the sensor housing 838 can be adjusted relative to the housing 802. For example, the sensor housing 838 can be screwed in or out via threads 840, thereby moving the coil FPCB100 relative to the movable member 832 until a signal is detected indicating a predetermined position of the poppet 818. The sensor housing 838 can then be locked in place with a lock nut 854.

[0077] In one example, the position sensor assembly 836 is configured as an on / off switch type sensor that is configured to determine whether the poppet 818 is seated in the poppet seat 820. In such a position, the valve 800 blocks fluid flow from the first port 810 to the second port 812.

[0078] In another example, the position sensor assembly 836 is configured as a proportional sensor capable of determining the axial position of the poppet 818 along a range of positions from a closed position (shown in FIG. 1 ) to a fully open position. In this example, the position of the movable member 832 may indicate the rate of fluid flow between the first port 810 and the second port 812.

[0079] Valve 800 is configured to operate in two modes of operation. In a first mode of operation, either no pilot fluid signal is applied to third port 816 or the fluid forces at first port 810 or second port 812 overcome the combined pilot fluid signal force and the spring force of spring 824. In this mode, fluid applied to first port 810 or second port 812 urges poppet 818 and piston 822 proximally against spring 824, thereby opening a fluid flow path between first port 810 and second port 812.

[0080] In particular, when fluid is supplied to the first port 810, the first port 810 pushes the poppet 818 proximally, disengaging the poppet 818 from the poppet seat 820, allowing fluid to flow from the first port 810 through the cavity inside the sleeve 804, the flow area formed between the (disengaged) poppet 818 and the inner surface of the sleeve 804, and through the cross-hole 814 to the second port 812. Similarly, when fluid is supplied to the second port 812, the second port 812 pushes the poppet 818 proximally, disengaging the poppet 818 from the poppet seat 820, allowing fluid to flow from the second port 812 to the first port 810 through the cross-hole 814 of the second port 812, the flow area formed between the (disengaged) poppet 818 and the inner surface of the sleeve 804, and through the cavity inside the sleeve 804.

[0081] In a first mode of operation, the position sensor assembly 836 provides a signal (e.g., generated by the coil FPCB100 and the process FPCB200) indicative of the position of the poppet 818. The position of the poppet 818 also indicates the rate of fluid flow through the valve 800.

[0082] In addition to the first mode of operation, the valve 800 can operate in a second mode of operation when a pilot fluid signal is applied to the third port 816. In this mode, the fluid force of the pilot fluid signal combines with the biasing force of the spring 824 to urge the piston 822 and poppet 818 distally, thereby seating the poppet 818 against the poppet seat 820 and blocking fluid flow between the first port 810 and the second port 812. As confirmation, the position sensor assembly 836 generates a signal indicating that the poppet 818 is seated against the poppet seat 820.

[0083] 9 is a flowchart of a method 900 for forming and operating an assembly (e.g., assembly 400 or assembly 700) according to one example embodiment. Method 900 may include one or more operations, functions, or acts, as indicated by one or more of blocks 902-910.

[0084] Although shown sequentially, these blocks may be performed in parallel and / or in a different order than described herein. Additionally, various blocks may be combined, reduced in number, divided into additional blocks, and / or eliminated based on the desired implementation. For these and other processes and methods disclosed herein, it should be understood that the flowcharts illustrate the functionality and operation of one possible implementation of the example. Those skilled in the art will appreciate that the scope of the examples disclosed herein includes alternative implementations in which functions may be performed in a different order than shown or described (including substantially simultaneously or in reverse order), depending on the functionality involved.

[0085] At block 902, method 900 includes providing a housing. As used herein, the term "provide," with respect to a component such as housing 402 or housing 702, includes any action taken to make the housing or any other component available for use, such as bringing the component, such as a housing, into an apparatus or work environment for further processing (e.g., attaching other components).

[0086] In block 904, the method 900 includes winding a coil FPCB (e.g., coil FPCB 100, 500) around a housing, the coil FPCB comprising: (i) an excitation coil printed as a conductive track on the coil FPCB, the excitation coil configured to generate a magnetic field when a current is supplied to the conductive track; and (ii) at least one detection coil printed as a respective conductive track on the coil FPCB, the at least one detection coil configured such that the magnetic field generated by the excitation coil induces a respective current in the at least one detection coil.

[0087] At block 906, the method 900 includes disposing a moveable member (eg, moveable member 404, 704) at least partially within the housing.

[0088] At block 908, the method 900 includes determining a change in a parameter (voltage, current, energy, etc.) associated with each current when the movable member moves (eg, linearly or rotationally) within the housing.

[0089] At block 910, the method 900 includes determining a position of the movable member based on a change in a parameter associated with each current.

[0090] Method 900 may include other steps described herein.

[0091] The foregoing detailed description, with reference to the accompanying drawings, describes various features and operations of the disclosed system. The exemplary embodiments described herein are not meant to be limiting. Certain aspects of the disclosed system can be arranged and combined in a variety of different configurations, all of which are contemplated herein.

[0092] Furthermore, unless the context indicates otherwise, features shown in each of the drawings may be used in combination with one another. Thus, the drawings are generally to be considered as partial aspects of one or more overall embodiments, with the understanding that not all of the illustrated features are required for each embodiment.

[0093] Additionally, any recitation of elements, blocks, or steps in the specification or claims is for purposes of clarity, and therefore, such recitation should not be construed as requiring or implying that these elements, blocks, or steps follow a particular arrangement or be performed in a particular order.

[0094] Furthermore, devices or systems may be used or configured to perform the functions illustrated in the figures. In some cases, device and / or system components may be configured to perform the functions, such that the components are actually configured and structured (in hardware and / or software) to enable such performance. In other examples, device and / or system components may be configured to be adapted to perform the functions, configured to be capable of performing the functions, or configured to be suitable for performing the functions, such as when operating in a particular manner.

[0095] The terms "substantially" or "about" mean that while exact realization of the recited characteristic, parameter, or value is not required, deviations or variations may occur, including, for example, tolerances, measurement errors, measurement accuracy limits, and other factors understood by those skilled in the art, in an amount that does not eliminate the effect that the characteristic was intended to provide.

[0096] The configurations described herein are for illustrative purposes only. As such, those skilled in the art will recognize that other configurations and elements (e.g., machines, interfaces, operations, sequences, and groupings of operations) may be substituted, or that some elements may be omitted entirely, depending on the desired results. Furthermore, many of the described elements are functional entities that may be implemented as discrete or distributed components, or in conjunction with other components, in any suitable combination and location.

[0097] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and not limitation, with the true scope being indicated by the following claims, along with the full scope of equivalents to which such claims are entitled. Additionally, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting in any way.

[0098] Accordingly, embodiments of the present disclosure may relate to one of the following exemplary embodiments (EEE):

[0099] EEE1 is an assembly comprising: a housing; a movable member configured to move within the housing; and a coil flexible printed circuit board (FPCB) wrapped around the housing, the coil FPCB comprising at least one excitation coil printed as a conductive track on the coil FPCB, the at least one excitation coil configured to generate a magnetic field when a current is supplied to the conductive track; and at least one detection coil printed as a respective conductive track on the coil FPCB, the magnetic field generated by the at least one excitation coil configured to induce respective currents in the at least one detection coil, and movement of the movable member within the housing changes a parameter associated with the respective currents, thereby indicating the position of the movable member.

[0100] EEE2 is the assembly of EEE1, wherein at least one excitation coil is printed as a spiral conductive track on the coil FPCB.

[0101] EEE3 is the assembly of EEE2, wherein the spiral conductive track is a rectangular spiral conductive track.

[0102] EEE4 is an assembly described in any of EEE1 to 3, comprising at least one first detector coil disposed laterally of the at least one excitation coil on a first side of the at least one excitation coil, and a second detector coil disposed laterally of the at least one excitation coil on a second side of the at least one excitation coil opposite the first side so that the at least one excitation coil is a central coil interposed between the first detector coil and the second detector coil, wherein when the movable member moves within the housing, a differential signal between the first detector coil and the second detector coil indicates the position of the movable member.

[0103] EEE5 is the assembly of EEE4, wherein at least one excitation coil extends along the length of the coil FPCB and is wound together around the housing, a first detection coil and a second detection coil extend along the length of the coil FPCB and are wound together around the housing, the movable member is configured to move linearly within the housing, and the differential signal indicates the linear position of the movable member within the housing.

[0104] EEE6 is an assembly according to any one of EEE1 to EEE5, comprising a first plurality of detector coils, at least one detector coil being arranged laterally of at least one excitation coil on a first side of the at least one excitation coil, and a second plurality of detector coils being arranged laterally of at least one excitation coil on a second side of the at least one excitation coil opposite the first side, so that the at least one excitation coil is a central coil interposed between the first plurality of detector coils, each coil of the first plurality of detector coils and the second plurality of detector coils being formed as a spiral conductive track, a movable member being rotatable within the housing, and a differential signal between a coil of the first plurality of detector coils and each coil of the second plurality of detector coils indicating a rotational position of the movable member within the housing.

[0105] EEE7 is the assembly of any of EEE1 to EEE6, wherein the conductive tracks of at least one excitation coil form multiple layers within the coil FPCB, and the conductive tracks of at least one detection coil each form multiple layers within the coil FPCB.

[0106] EEE8 is the assembly of any one of EEE1 to EEE7, wherein the coil FPCB is wound around the housing two or more times.

[0107] EEE9 is the assembly of any of EEE1 to EEE8, further comprising a processing FPCB coupled to the coil FPCB, the processing FPCB including conditioning and sensing circuitry electrically coupled to the conductive tracks of at least one excitation coil and to each conductive track of at least one sensing coil.

[0108] EEE10 is the assembly of EEE9, wherein the coil FPCB is wound around the housing and the processing FPCB is wound therewith, the processing FPCB including a plurality of segments so as to form a polygonal shape having flat surfaces on which the electronic components of the regulating and sensing circuitry are mounted.

[0109] EEE11 is the assembly of any of EEE1-10, wherein the conductive tracks of the at least one excitation coil are different from the respective conductive tracks of the at least one sensing coil.

[0110] EEE12 is a valve comprising: a housing; a plurality of ports including a first port and a second port; a poppet movable relative to the housing; a spring that applies a spring force to the poppet; a movable member disposed within the housing and coupled to the poppet; and a coil flexible printed circuit board (FPCB) wrapped around the housing, the coil FPCB comprising: (i) at least one excitation coil printed as a conductive track on the coil FPCB, the at least one excitation coil configured to generate a magnetic field when an electric current is supplied to the conductive track; and (ii) at least one detection coil printed as a respective conductive track on the coil FPCB, the magnetic field generated by the at least one excitation coil configured to induce a respective electric current in the at least one detection coil; wherein fluid supplied to the first port presses the poppet against the spring, thereby opening a flow path between the first port and the second port; and movement of the movable member with the poppet within the housing changes a parameter associated with each electric current, thereby indicating the position of the movable member and the poppet.

[0111] EEE13 is the valve of EEE12, further comprising a sensor carrier attached to the housing and wound with the coil FPCB.

[0112] EEE14 is the valve of EEE12 or 13, further comprising a sensor housing threadedly engaged with the valve housing such that its axial position is adjustable relative to the housing, and for calibration, adjusting the axial position of the sensor housing moves the coil FPCB relative to the movable member.

[0113] EEE15 is the valve of any of EEE12-14, wherein the at least one excitation coil is printed as a rectangular spiral conductive track on the coil FPCB.

[0114] EEE16 is a valve according to any one of EEE12 to 15, comprising a first detector coil disposed laterally of the at least one excitation coil on a first side of the at least one excitation coil, and a second detector coil disposed laterally of the at least one excitation coil on a second side of the at least one excitation coil opposite the first side, such that the at least one detector coil is a central coil interposed between the at least one excitation coil and the first detector coil, wherein when a movable member moves within the housing, a differential signal between the first detector coil and the second detector coil indicates the position of the movable member.

[0115] EEE17 is the valve of EEE16, wherein at least one excitation coil extends along the length of the coil FPCB and is wound around the housing therewith; first and second detection coils extend along the length of the coil FPCB and are wound around the housing; the movable member is configured for linear movement within the housing; and the differential signal indicates the linear position of the movable member within the housing.

[0116] EEE18 is the valve of any one of EEE12 to 17, wherein the conductive tracks of at least one excitation coil form multiple layers within the coil FPCB, and the conductive tracks of at least one detection coil each form multiple layers within the coil FPCB.

[0117] EEE19 is the valve of any one of EEE12 to 18, further comprising a process FPCB coupled to the coil FPCB, the process FPCB including regulation and detection circuitry electrically coupled to the conductive tracks of the at least one excitation coil and to each conductive track of the at least one detection coil.

[0118] EEE20 is the valve of EEE19, wherein the coil FPCB is wound around the housing and the process FPCB is wound therewith, the process FPCB including a plurality of segments so as to form a polygonal shape having flat surfaces on which the electronic components of the regulating and sensing circuitry are mounted.

Claims

1. Housing and a movable member configured to move within the housing; a coil flexible printed circuit board (FPCB) wrapped around the housing, at least one excitation coil printed as a conductive track on the coil FPCB, the at least one excitation coil being configured to generate a magnetic field when a current is supplied to the conductive track; at least one detector coil printed as a respective conductive track on the coil FPCB, wherein the magnetic field generated by the at least one excitation coil is configured to induce respective currents in the at least one detector coil, and movement of the movable member within the housing indicates a position of the movable member by changing a parameter associated with the at least one excitation coil or the respective currents in the at least one detector coil; a coil FPCB comprising: An assembly comprising:

2. The assembly of claim 1 , wherein the at least one excitation coil is printed as a spiral conductive track on the coil FPCB.

3. 3. The assembly of claim 2, wherein the spiral conductive track is a rectangular spiral conductive track.

4. The at least one sensing coil a first detection coil disposed laterally of the at least one excitation coil on a first side of the at least one excitation coil; a second detector coil disposed laterally of the at least one excitation coil on a second side of the at least one excitation coil opposite the first side such that the at least one excitation coil is a central coil interposed between the first detector coil and the at least one excitation coil, wherein when the movable member moves within the housing, a differential signal between the first detector coil and the second detector coil indicates the position of the movable member; and The assembly of claim 1 , comprising:

5. 5. The assembly of claim 4, wherein the at least one excitation coil extends along a length of the coil FPCB and is wound therewith around the housing, the first and second detector coils extend along the length of the coil FPCB and are wound together around the housing, the movable member is configured to move linearly within the housing, and the differential signal indicates a linear position of the movable member within the housing.

6. The at least one sensing coil a first plurality of sensing coils disposed laterally of the at least one excitation coil on a first side of the at least one excitation coil; a second plurality of detector coils disposed laterally of the at least one excitation coil on a second side of the at least one excitation coil opposite the first side such that the at least one excitation coil is a central coil interposed between the first plurality of detector coils, wherein each coil of the first plurality of detector coils and the second plurality of detector coils is formed as a spiral conductive track, the movable member is rotatable within the housing, and a differential signal between a coil of the first plurality of detector coils and each coil of the second plurality of detector coils indicates a rotational position of the movable member within the housing; and The assembly of claim 1 , comprising:

7. 2. The assembly of claim 1, wherein the conductive tracks of the at least one excitation coil form multiple layers in the coil FPCB, and the respective conductive tracks of the at least one sense coil form multiple layers in the coil FPCB.

8. The assembly of claim 1 , wherein the coil FPCB is wrapped around the housing two or more times.

9. 10. The assembly of claim 1, further comprising a processing FPCB coupled to the coil FPCB, the processing FPCB including conditioning and sensing circuitry electrically coupled to the conductive tracks of the at least one excitation coil and the respective conductive tracks of the at least one sensing coil.

10. 10. The assembly of claim 9, wherein the coil FPCB is wrapped around the housing and the processing FPCB is wrapped therewith, the processing FPCB including a plurality of segments such that the processing FPCB forms a polygonal shape having flat surfaces on which electronic components of the adjusting and sensing circuitry are mounted.

11. The assembly of claim 1 , wherein the conductive tracks of the at least one excitation coil are different from the respective conductive tracks of the at least one sensing coil.

12. Housing and a plurality of ports including a first port and a second port; a poppet movable relative to the housing; and a spring applying a spring force to the poppet; a movable member disposed within the housing and coupled to the poppet; a coil flexible printed circuit board (FPCB) wrapped around the housing, the coil FPCB comprising: (i) at least one excitation coil printed as a conductive track on the coil FPCB, the at least one excitation coil configured to generate a magnetic field when a current is supplied to the conductive track; and (ii) at least one detector coil printed as a respective conductive track on the coil FPCB, the at least one detector coil configured such that the magnetic field generated by the at least one excitation coil induces a respective current in the at least one detector coil; a valve wherein fluid supplied to the first port presses the poppet against the spring, thereby opening a flow path between the first port and the second port, and wherein movement of the movable member with the poppet within the housing changes a parameter associated with each of the currents, thereby indicating a position of the movable member and the poppet.

13. 13. The valve of claim 12, further comprising a sensor carrier attached to the housing and wound with the coil FPCB.

14. 13. The valve of claim 12, further comprising a sensor housing threadably engaged with the housing of the valve such that its axial position is adjustable relative to the housing, wherein adjusting the axial position of the sensor housing moves the coil FPCB relative to the movable member for calibration.

15. 13. The valve of claim 12, wherein the at least one excitation coil is printed as a rectangular spiral conductive track on the coil FPCB.

16. The at least one sensing coil a first detection coil disposed laterally of the at least one excitation coil on a first side of the at least one excitation coil; a second detector coil disposed laterally of the at least one excitation coil on a second side of the at least one excitation coil opposite the first side such that the at least one excitation coil is a central coil interposed between the first detector coil and the at least one excitation coil, wherein when the movable member moves within the housing, a differential signal between the first detector coil and the second detector coil indicates the position of the movable member; and The valve of claim 12, comprising:

17. 17. The valve of claim 16, wherein the at least one excitation coil extends along a length of the coil FPCB and is wound therewith around the housing, the first and second detector coils extend along the length of the coil FPCB and are wound around the housing, the movable member is configured for linear movement within the housing, and the differential signal indicates a linear position of the movable member within the housing.

18. 13. The valve of claim 12, wherein the conductive tracks of the at least one excitation coil form multiple layers in the coil FPCB, and the respective conductive tracks of the at least one sense coil form multiple layers in the coil FPCB.

19. 13. The valve of claim 12, further comprising a processing FPCB coupled to the coil FPCB, the processing FPCB including conditioning and sensing circuitry electrically coupled to the conductive tracks of the at least one excitation coil and the respective conductive tracks of the at least one sensing coil.

20. 20. The valve of claim 19, wherein the coil FPCB is wrapped around the housing and the processing FPCB is wrapped therewith, the processing FPCB including a plurality of segments to form a polygonal shape having flat surfaces on which electronic components of the regulating and sensing circuitry are mounted.

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