ELECTRONIC RAM PUMP CONTROLLER

Abstract

The present invention is a wireless electronic control device, primarily intended to be attached to the impulse valve of a Hydraulic Ram Pump (HRP), enabling remote automatic and manual management of the HRP. The Electronic Ram Pump Controller (ERPC) may be used to control the HRP, through the restriction of the fluids entering/or exiting the pump. In the presented form, the Impulse Valve Manager (IVM), attaches to an impulse valve and restricts, to a varying degree, the aperture size of the impulse valve. Through this control mechanism the HRP may be sealed, started, or tunedeither remotely by a user or automatically through the ERPC's automated systems. The presented version can be augmented with valve actuation and sensing of the impulse cycle. The ERPC may be retrofitted or incorporated into the design of a new HRP.

Claims

1. A hydraulic ram pump electronic controller comprising: a housing for connection to a hydraulic ram pump; an elongate stem for coupling to a valve in the hydraulic ram pump to control the maximum aperture of the valve as it opens and closes under the action of a fluid in the hydraulic ram pump, the elongate stem having a longitudinal axis, a first end and a second end, the first end of the elongate stem coupling to the valve, and the elongate stem and being mounted with respect to the housing to freely move bi-directionally along its longitudinal axis under influence of pressure variations in the fluid; a limiting element for limiting the movement of the elongate stem along its longitudinal axis in a direction towards its first end; a drive unit for adjusting the positon of the limiting element with respect to the housing, wherein the limit on the movement of the elongate stem provided by the limiting element sets the maximum aperture of the valve; and a control circuit connected to the drive unit, the control circuit being configured to instruct the drive unit to adjust the position of the limiting element based on a desired maximum valve aperture.

2. The hydraulic ram pump electronic controller of claim 1, comprising: a valve aperture sensor for determining the current open/closed extent of the valve and/or the current maximum aperture setting of the valve, and providing a signal indicative of the current open/closed extent and/or the current maximum aperture to the control circuit; wherein the valve aperture sensor is one or more of a pressure sensor arranged to detect the pressure variations inside the pump, a linear position sensor on the elongate stem for measuring the position of the elongate stem with respect to the housing, an accelerometer mounted on the elongate stem, or a linear position sensor on the limiting element for measuring the position of the limiting element with respect to the housing.

3. The hydraulic ram pump electronic controller of claim 1 or 2, comprising: a retaining element on the elongate stem located towards its second end, the retaining element engaging with the limiting element to limit the movement of the elongate stem in a direction towards its first end.

4. The hydraulic ram pump electronic controller of claim 3, wherein: the retaining element on the elongate stem is a magnet; and the limiting element includes a first coil that is electrically coupled to the control circuit.

5. The hydraulic ram pump electronic controller of claim 4, wherein the motion of the magnet relative to the first coil induces a signal in the first coil that enables the control circuit to sense the position and movement of the elongate stem and/or determine the current maximum aperture setting of the valve.

6. The electronic controller of claim 4 or 5, further comprising a power storage device coupled to the first coil and coupled to the control circuit and/or drive unit; wherein the induced current in the first coil due to the motion of the magnet relative to the first coil is used to generate power that is stored in the power storage device and is used to power the control circuit and/or drive unit.

7. The electronic controller of any of claims 4 to 6 wherein: the electronic controller further comprises a second coil that is electrically coupled to the control circuit; and the control circuit is configured to send a signal to the second coil to create an electromagnetic force on the magnet that moves the elongate stem in a direction towards its first end in order to open the valve and/or accelerates/decelerates the elongate stem.

8. The electronic controller of any preceding claim, further comprising a spring member that is configured to produce a force on the elongate stem in a direction towards its first end.

9. The electronic controller of any preceding claim, wherein the limiting element is configured to be moveable parallel to the longitudinal axis of the elongate stem.

10. The electronic controller of any preceding claim, wherein the housing comprises a base plate onto which the limiting element is mounted.

11. The electronic controller of any preceding claim, wherein the housing includes mounting elements allowing the electronic controller to be retrofitted to the hydraulic ram pump.

12. The electronic controller of any preceding claim, wherein: the electronic controller further comprises a power storage device that is configured to power the control circuit and/or drive unit; and the power storage device is configured to receive power from at least one of an external power supply, a solar cell, a micro hydro generator, or an internal turbine in the hydraulic ram pump.

13. The electronic controller of any preceding claim, wherein either: the drive unit comprises a screwthread connected to a stepper motor controlled by the control circuit, and rotation of the screwthread moves the limiting element parallel to the axis of the elongate stem; or the drive unit comprises a pneumatic or hydraulic element controlled by the control circuit and configured to move the limiting element parallel to the axis of the elongate stem.

14. The electronic controller of any of claims 3 to 13, wherein: the limiting element is a socket; and the elongate stem passes through the socket such that the retaining element engages with the socket to limit the movement of the elongate stem in a direction towards its first end.

15. The electronic controller of any of claims 1 to 12, wherein the limiting element is mounted on a threaded protrusion.

16. The electronic controller of claim 15, wherein the drive unit rotates the limiting element about the threaded protrusion to adjust the positon of the limiting element with respect to the housing.

17. The electronic controller of claim 15 or 16, wherein the elongate stem extends through a hollow center of the threaded protrusion.

18. The electronic controller of any of claims 15 to 17, wherein the drive unit, the elongate stem and the limiting element are collinear along the longitudinal axis of the elongate stem.

19. The electronic controller of any preceding claim, wherein: the housing is a sealed unit that encases the electronic controller; the housing includes an exit for the first end of the elongate stem; and the exit in the housing includes a sealing member configured to facilitate movement of the elongate stem.

20. The electronic controller of any of claims 1 to 18 wherein: the housing is a first housing that encases the elongate stem, limiting element and drive unit; and the electronic controller further comprises a second housing that encases the control circuit.

21. The electronic controller of claim 20 when dependent on claim 12, wherein the power storage device is encased within the second housing.

22. The electronic controller of claim 20 or 21 wherein the first housing is a sealed unit that includes an exit for the first end of the elongate stem.

23. The electronic controller of any of claims 20 to 22 wherein the second housing is a sealed unit.

24. The electronic controller of any preceding claim, wherein: the control circuit includes a memory that is configured to store previous instructions sent to the drive unit; and the control circuit is configured to determine the position of the limiting element with respect to the housing based on the stored previous instructions.

25. The electronic controller of any preceding claim, wherein the control circuit is configured to send and/or receive telemetry signals to/from a remote operator which can control the electronic controller remotely.

26. The electronic controller of any preceding claim, wherein the first end of the elongate stem is suitable for coupling to either the impulse value or the delivery valve of the hydraulic ram pump.

27. A pump system comprising a hydraulic ram pump and the electronic controller of any of claims 1 to 26.

28. A method for controlling a hydraulic ram pump, the hydraulic ram pump having a valve, and an electronic controller with a housing connected the hydraulic ram pump; an elongate stem for coupling to a valve in the hydraulic ram pump to control the maximum aperture of the valve as it opens and closes under the action of a fluid in the hydraulic ram pump, the elongate stem having a longitudinal axis, a first end and a second end, the first end of the elongate stem coupling to the valve, and the elongate stem and being mounted with respect to the housing to freely move bi-directionally along its longitudinal axis under influence of pressure variations in the fluid; a limiting element for limiting the movement of the elongate stem along its longitudinal axis in a direction towards its first end; and a drive unit for adjusting the positon of the limiting element with respect to the housing, wherein the limit on the movement of the elongate stem provided by the limiting element sets the maximum aperture of the valve; wherein the method comprises: receiving, at the electronic controller from a remote operator, a control signal including one or more commands and/or one or more setting parameters; adjusting, by the drive unit of the electronic controller, the position of the limiting element based on the received control signal, in order to set the maximum valve aperture to a desired value.

29. The method of claim 28, further comprising: determining one or more operating parameters indicating performance of the hydraulic ram pump, and sending a signal to the remote operator indicative of the determined one or more operating parameters.

30. The method of any of claims 28 to 29, further comprising: positioning the limiting element at the end of its travel span in a direction towards the first end of the elongate stem, to fully open the valve in the hydraulic ram pump to start up the pump or perform a cleaning flush of the valve; and/or positioning the limiting element at the end of its travel span in a direction towards the second end of the elongate stem, to fully close the valve in the hydraulic ram pump and shut down the pump.

31. The method of any of claims 28 to 30, wherein the electronic controller includes a retaining element which is a magnet on the elongate stem located towards its second end, and the limiting element includes a first coil, the method further comprising: detecting a signal induced in the first coil by the motion of the magnet relative to the first coil, the induced signal being indicative of the movement of the elongate stem and/or the current maximum aperture setting of the valve.

32. The method of any of claim 31, wherein the electronic controller further comprises a second coil, the method further comprising: sending a signal to the second coil, the signal creating an electromagnetic force on the magnet that moves the elongate stem in a direction towards its first end in order to open the valve and/or accelerates the elongate stem.

33. A hydraulic ram pump electronic controller comprising: a housing for connection to a hydraulic ram pump; a drive unit coupled to a retaining arm in a valve in the hydraulic ram pump, wherein the retaining arm controls the maximum aperture of the valve as it opens and closes under the action of a fluid in the hydraulic ram pump, the drive unit being configured to adjust the positon of the retaining arm with respect to the housing; a control circuit connected to the drive unit, the control circuit being configured to instruct the drive unit to adjust the position of the retaining arm based on a desired maximum valve aperture.

34. The hydraulic ram pump electronic controller of claim 33, wherein the adjusting of the positon of the retaining arm includes rotating the retaining arm.

35. The hydraulic ram pump electronic controller of claim 34, wherein the retaining arm is rotated via an elongate stem coupled between the retaining arm and the drive unit.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0012] Further details of the invention are explained in more detail below in relation to the accompanying drawings, in which:

[0013] FIG. 1 shows a profile view of the impulse manager attached to a modified Blake style HRP.

[0014] FIG. 2 shows a cross-sectional view of the HRP. In order to show the unhindered working of a HRP's valves.

[0015] FIG. 3 shows an orthogonal view of the impulse manager, with key parts exposed.

[0016] FIG. 4 shows a cross-sectional view of the impulse manager attached to the HRP.

[0017] FIG. 5 shows a cross-sectional view of a Blake rubber washer style impulse valve.

[0018] FIG. 6 shows an IVM configuration for a Blake rubber washer style impulse valve.

[0019] FIG. 7 shows a simplified flow chart from the firmware of a typical impulse manager.

[0020] FIG. 8 shows a cross sectional view of a hydraulic ram pump electronic controller according to an embodiment of the present invention.

[0021] FIG. 9 shows a perspective view of the interior components of the mechanical enclosure of FIG. 8.

DETAILED DESCRIPTION

[0022] The presented invention is a wireless electronic control device, primarily intended to be attached to the impulse valve of a Hydraulic Ram Pump (HRP), enabling remote automatic and manual management of the HRP.

[0023] The Electronic Ram Pump Controller (ERPC) may be used to control the HRP, through the restriction of the fluids entering/or exiting the pump. In the presented form, the ERPC is an Impulse Valve Manager (IVM), that attaches to the impulse valve and restricts, to a varying degree, the aperture size of the impulse valve. Through this control mechanism the HRP may be sealed, started, or tuned; either remotely by a user or automatically through the ERPC's automated systems. The presented version can be augmented with valve actuation and sensing of the impulse cycle. The ERPC may be retrofitted or incorporated into the design of a new HRP.

[0024] According to FIG. 1, the preferred embodiment of the HRP is based on a Blake Ram Pump (as in Hydraulic Ram Pumps: A guide to ram pump water supply systems) with a moving plug. Here, an impulse valve 102 is bolted onto the pump manifold 100 (the impulse valve is made up of a number of parts detailed in FIG. 2). Bolts 10 and nuts 12 are shown holding respective parts together. A drive pipe 104 is attached to the pump manifold. The drive pipe connects the manifold to the supply reservoir (not shown). An air induction (or sniffer) valve 108 is screwed into the manifold 100 for the introduction of air during each cycle. This replaces air lost due to adsorption and ensures a viable air pocket is kept in the air vessel 106. The air vessel 106 is also bolted to the manifold. In this example, though not in all embodiments, an inspection plate 114 for the inspection and maintenance of the delivery valve 124, (as depicted in FIG. 2) is incorporated. The delivery pipe 112 is screwed into the air vessel 106, this connects the pump to the delivery reservoir (not shown). A bleed tap made up of the bleed tap body 116 and the bleed tap handle 118, enables the air chamber to be bled or filled as required.

[0025] Further detail of the HRP depicted in FIG. 1, is given in the cross-sectional view of FIG. 2. For simplicity, the impulse valve manager is omitted in this view. The impulse valve plate 120 is bolted to the pump manifold 100 above a rubber seal 14as shown in FIG. 2. The valve stem 126 is set in the centre of the valve plate 120, and is able to move freely along the vertical axis. The other end of the valve stem has a counterweight attached 134, this weight can be varied to alter the performance and cycle rate of the pump. The delivery check valve 124, a rubber washer, is mounted to a spur on the air vessel 106. When pressure is higher in the air vessel 106 than the pump manifold 100, then the valve deforms to form a seal against the bottom edge of the vessel. When the pressure is higher in the pump manifold 100, the valve deforms to induct water into the air vessel and equalize the pressure.

[0026] Alternatively, a spring can be mounted instead of the counterweight 134. This spring arrangement can be altered by adjusting the stiffness of the spring or altering its compression.

[0027] Furthermore, the entire valve stem 126 and valve plate 102 assembly can be swapped out of a fixed stem and replaced with a flexible rubber valve that deforms around a fixed centre (as evidenced in Hydraulic Ram Pumps: A guide to ram pump water supply systems and other technical releases from Warwick University UK). This alternate arrangement can be referred to as a Blake Style Valve. This enables the cycle and performance of the pump to be modified through the replacement of the rubber for a new valve of different stiffness, or the restriction of the gap to which the rubber can open.

[0028] There are many variants and modifications that can be made to the HRP, relevant to this invention.

[0029] Alternatively to the flexible rubber check valve 124 a solid plate valve or indeed any other check valve may be utilized in its place.

[0030] Alternatively the manifold 100 may be constructed to enable the impulse valve to be mounted in various configurations, including between the air vessel 106 and the drive pipe 104 or on the same axis as the drive pipe 104.

[0031] The modifications required to the standard HRP are shown in FIG. 1 and FIG. 2 in order to mount the preferred embodiment of the IVM, include that; [0032] 1. The mounting bolts 136 should be affixed to the valve seat 120 or the pump manifold 100 (as shown in FIG. 4). [0033] 2. The valve stem 126 should be modified or replaced in order to be long enough to enter the impulse valve manager (as shown in FIG. 3).

[0034] FIG. 4 shows a cross-sectional view of IVM. The IVM is mounted astride the mounting bolts 136 to stabilize the manager body 138, this enables the impulse valve manager to be levelled and positioned. The manager body 138, in conjunction with the lid 140 and valve stem boot 142 (housing), creates a seal for the internal parts of the mechanism against water and debris. The valve stem boot (sealing member) is affixed to the valve stem 126 (elongate stem) and the manager body 138. The valve stem is aligned with a linear bushing 144, which reduces wear on the stem and enables further alignment of the valve stem 126. Affixed to the valve stem is the stem magnet 146 (retaining element), which is secured by the valve stem upper nut 128. The stem magnet acts as a retainer, limiting aperture size that the valve can achieve through contact with the stem socket plate 148 (limiting element). The stem socket plate 148 is able to move vertically on the linear bearings 150, as also shown in FIG. 3.

[0035] The valve stem assembly (consisting of 126,128,130,132,146) moves in a reciprocating motion along the vertical axis, during the cycle of the HRP. This motion of the stem magnet 146 past the main coil 152 and auxiliary coil 154 develops a current in those coils. The coils are mounted such that this current can be used for sensing the position and frequency of the HRP cycle. The main coil 152 can also be used to generate power that is then stored in the battery pack 156 (power storage device). The auxiliary coil 154 can provide an electromagnetic force field that will attract the stem magnet 146 for a variety purposes including hydraulic ram pump restart and/or cycle augmentation. This process is conducted and controlled by the microcontroller and power management board 158 (control circuit). The main coil 152 and auxiliary coil 154 are both monitored by the microcontroller 158, to give the microcontroller further information on the cycle and performance of the HRP.

[0036] FIG. 3 further illustrates the presented mechanism, such that the position of the stem socket plate 148 is restricted by the lead screw 160 and lead nut 162 which is mounted into the stem socket plate 148. The lead screw is mounted into the impulse manager body 138 at one end, and at the other connects to a belt 164 and pulley 166 system connected to a stepper motor 168 (drive unit). The stepper motor is controlled by microcontroller 158 powered from a battery 156. The microcontroller can perform automated tasks and/or receive further inputs using a telemetry uplink and remote control.

[0037] This configuration enables the preferred embodiment which allows for the automatic or remote control of the HRP for the following processes, amongst others: [0038] (A) Full shut offthe HRP may be switched off by moving the stem socket 148 to the top of its travel span, compressing the impulse valve plug 132 against the valve seat 120 to create a seal. [0039] (B) Variable controlsuch that the maximum aperture that the impulse valve plug 132 creates during the cycle can be modified to alter the performance (flow rate, efficiency etc.) to the user's requirements. [0040] (C) Startthe HRP may be started by the lowering of the stem socket 148 and if required the energizing of the auxiliary coil 154 to fully open the impulse valve and start the HRP cycle. [0041] (D) Cleaning flushthe HRP may be flushed clear by the full opening of the impulse valve (lowering of the stem socket plate 148) to its lowest position for any blockages or debris to be cleared.

[0042] These operations and others can be performed automatically by the microcontroller and power board 158, in conjunction with its sensing of the cycle through the main coil 152 or in a remote-control mode where telemetry signals are sent and received by the microcontroller 158. The addition of these operations, remote and automatic control and the ability to sense and relay the condition of the pump provide many of the advantages of the present invention.

[0043] FIG. 5 shows the cross-sectional view of the Blake rubber washer style impulse valve, in the open position (the manifold and securing bolts are not shown). A rubber washer 204, is held between the retaining arm 202 and the valve basket 206. The retaining arm 202 has a central threaded shaft that sits inside a female thread in the valve basket. The position of the retaining arm is maintained by the valve basket nut 208. The valve basket 206 has a series of slots (or holes) in it that enable the fluid to escape, when the force exerted by the fluid on the lower surface of the rubber washer 204 surpasses the washer stiffness, the washer deforms creating a seal between its upper surfaces and the valve basket. The aperture, and thereby the performance, of the valve is set by altering the vertical position of the retaining arm.

[0044] FIG. 6 details a configuration of the presented invention designed to work with the Blake rubber washer style impulse valve shown in FIG. 5. In this configuration the stepper motor 168 is connected to the retaining arm 210, by a belt 164 and pulleys 166. The manager body 138 has been modified slightly as shown in FIG. 6. A rotary bushing 210 is also used to seal the unit (in place of the linear bushing 144). The retaining arm 202 is able to slide vertically along its axis, as it turns due to the thread. To enable this the pulley 212 (a modified version of pulley 166) has a sliding keyway connection, thus the retaining arm can move vertically inside pulley 212 without losing the rotation alignment. This allows the microcontroller to open and close the Blake rubber washer style valve by rotating the retaining arm. All other parts are as labelled in FIG. 4.

[0045] In FIG. 7, a typical semi-autonomous programme used in the microcontroller is presented. Many modifications and alternatives to the semi-autonomous programme shown in FIG. 7 can be made depending on the Installation of the HRP and ERPC. Alternatively, a full control programme may be run at an offsite server, or a series of IVMs may be connected remotely to make collective decisions on performance.

[0046] The main programme loop contains five decisions, that decide the stream of that loop iteration: (1) Has the IVM received new operation commands (2) Has the IVM received new settings? (3) Is the impulse valve open or closed? (4) Is the Pump's performance within parameters, (5) if the valve is closed is it time to reopen it? If the responses to (1-3) are no and yes to (4), then the impulse manager will make no alterations to the impulse valve. This would be the by far the most common loop for the programme to take.

[0047] If external command for an operation (A, C or D) has been received then that will be performed and the IVM will progress to the next loop. If new performance settings have been received, they will be stored in the firmware of the IVM and the loop will progress to (3)this enables (B) remote variable control. If at (3) the impulse valve is openthen the IVM will take readings of the pump's performance, relay that information to control (usually a remote server) and then progress to decision (4). The IVM will then decide whether the pump is performing within the parameters of its settings: If a blockage is detected it may perform a flush of the HRP; If the discharge is too high it may restrict the aperture; If the discharge is too low it may increase the aperture.

[0048] If decisions (1-3) are answered with no the IVM will check if the closure time has elapsed and it is time to open the impulse valve, at decision (5), if it is then the valve will open and the pump be restarted, if not the programme will progress to the next loop.

[0049] In this embodiment, power can be supplied for the charging of the battery 156 through the take-off and rectifying of current from the main coil.

[0050] FIG. 8 shows a hydraulic ram pump electronic controller according to another embodiment of the present invention. In FIG. 8 a split enclosure configuration is detailed, with the mechanical parts housed in a mechanical enclosure (housing) 300. The mechanical enclosure seals directly to an impulse valve plate 302. The impulse valve plate 302 is bolted to the pump manifold 100 with a gasket 14 in-between (bolts and nuts not visible). The mechanical lower deck 304 is screwed into the valve plate 302 by means of a threaded protrusion. Interior to the mechanical lower deck 304 and running its axial length is a bushing 306 (made of a high slip material) that reduces friction and wear on the valve stem 126. The upper mechanical deck 308 is held in place by the four inter-deck columns 310. The valve stem assembly (consisting of 126,128,130,132) is usually free to move in the reciprocating motion described above (in FIG. 8 the impulse valve is shown in the fully closed position). The lowermost position of the valve stem assembly (consisting of 126,128,130,132) is dictated by the threaded valve deck 314, which in FIG. 8 is extended to its upper most position. In other words, the valve deck 314 acts as the limiting element, in a similar fashion to the stem socket of the previous embodiments. The valve deck thread runs along the upper threaded protrusion of the mechanical lower deck 304. Alternative screwing mechanisms are also possible. The valve deck 314 is connected to two armature linear bearings 316 (as also shown in FIG. 9). The valve deck 314 is free to move up and down the armature linear bearings 316, as it is rotated, following the thread of the lower mechanical deck 304. The armature linear bearings 316 are fused at the upper end into the stepper armature 318, the armature in turn is connected to the stepper motor's 168 shaft. When the stepper motor 168 is excited, it rotates the armature assembly (consisting of 316, 318) in turn rotating the valve deck 314 against the mechanical lower deck 304. This enables the mechanism to modify and restrict the movement of the valve stem assembly (consisting of 126,128,130,132). The locking pin 312 is used to maintain the rotation of the armature assembly (consisting of 316 & 318)and therein the lateral position of the valve deck 314. When the locking pin 312 is retracted above the stepper armature 318, the armature can spin freely. When the locking pin 312 is down it secures against the notched edge of stepper armature 318 (as also shown in FIG. 9). The electronics, power, sensor and telemetry systems required to control and mechanism are housed in the electronics enclosure 320, shown in FIG. 8 with an antenna 322 and an umbilical cable 324. No sensors or power mechanisms are shown in FIG. 8 for simplicity, however sensors and/or power mechanisms may be added.

[0051] FIG. 9 shows a view of the same split configuration as FIG. 8, but with the enclosure 300 removed. This split configuration has the advantage of protecting the electronics from water ingress. The integration of the valve stem assembly (consisting of 126,128,130,132) inside the lower mechanical deck 304 also removes alignment issues. This configuration is more appropriate for larger pumps due to its height.

[0052] Various modifications can be made to the preferred embodiments:

[0053] Various other sensors can be included to augment the impulse valve manager, including but not limited to: a linear position sensor on the valve stem; a linear position sensor on the stem socket; an accelerometer mounted on the valve stem; a pressure sensor mounted in the manifold or air chamber.

[0054] A break or latching mechanism may be added to the lead screws, stepper motor or linear bearings to ensure that the magnet socket remains fixed.

[0055] The split configuration (shown in FIG. 8) could also be used with a blake style impulse valve (shown in FIG. 5), using the same adaptations as the embodiment of FIG. 6.

[0056] The main coil may be divided into various sub coils in-order to obtain higher resolution sensing.

[0057] The auxiliary coil can be mounted to the lid 140 and configured to repel the stem magnet 146. Alternatively, the auxiliary coil may be omitted, or may be used in conjunction with or replaced altogether by a spring braced against the lid 140. The spring would, as the auxiliary coil can, provide an initial force when opening the valve from the closed position. The spring would be designed to break the initial inertia due to water pressure on the valve.

[0058] In high stress applications a bracing plate may be added beneath the stem magnet to reduce the wear and tear on the magnet.

[0059] The stepper motor may be mounted in a variety of ways including, but not limited to, directly to the lead screw through the lower surface of the manager body.

[0060] Alternative electrical motors or devices other than a stepper motor may be used.

[0061] A pneumatic or hydraulic mechanism (either rotary or linear) could be used instead to modify the valve aperture by replacing the stepper motor assembly shown in the exemplary embodiments. Hydraulic or pneumatic power could be drawn directly from the pressure in the HRP.

[0062] The stem boot may be replaced with a sealing linear bearing.

[0063] A brake may be used to secure the position of the stepper motor (drive unit).

[0064] The ERPC can be designed as an integral part of the HRP, rather than the retrofittable version demonstrated here in the preferred embodiment.

[0065] A variety of power sources can be used to supplant or augment generation from the main coil. This includes, amongst other external supply, solar, local micro hydro, internal turbine etc.

[0066] The presented invention can be modified in design in a multitude of manners. Possible mounting options include, but are not limited to: fitting the mechanism inside the manifold of valve seat; integrating the mechanism into the manifold; or fitting it into the valve itself.

[0067] Alternatively, the mechanism could be fitted to the delivery valve (check valve) instead of or as well as the impulse valve (waste valve), to provide a further control or compound control to the HRP.

[0068] The features of the embodiments outlined above may be combined in different ways where appropriate. Various modifications to the embodiments described above are possible and will occur to those skilled in the art without departing from the scope of the invention which is defined by the following claims.