Electronic device comprising an internal power source

Abstract

The present description relates to a device (101) comprising: a generator (308) suitable for producing electrical power from the circulation of fluid through a body of the device; a capacitive element (103) for storing the electrical power that is produced; a switch connecting the capacitive element for storing power to a first electronic circuit and to the generator; and a second electronic circuit (209) for moving the switch to an open state when: a first voltage, supplied by the generator, is less than a first threshold; and a second voltage, present across the terminals of the capacitive element, is less than a second threshold.

Description

DESCRIPTION Electronic device including an internal power source This application is based on, and claims priority from, French patent application no. FR2202597 filed on March 24, 2022 and entitled "Electronic device comprising an internal power source", which is considered to form an integral part of this description within the limits provided by law. technical field

[0001] This description applies generally to electronic devices and, in particular, to electronic devices with an internal or embedded power supply. More specifically, this description applies to the field of electronic water meters. Previous technique

[0002] With the development of diverse fields of application such as the Internet of Things (IoT) and home automation, electronic devices with internal power supplies are becoming increasingly common. Compared to electronic devices powered by an external source such as a mains power grid, these devices overcome various constraints, particularly regarding installation. However, electronic devices with an internal power supply, such as a non-rechargeable battery, require time-consuming operations to replace or recharge their power source. Summary of the invention

[0003] There is a need to improve all or part of existing electronic devices that incorporate an internal power supply. In particular, there is a need to reduce, or even eliminate, the constraints associated with replacing or recharging the power supplies embedded in existing electronic devices.

[0004] One embodiment overcomes all or part of the known disadvantages of electronic devices incorporating an internal power supply.

[0005] One embodiment aims to optimize the charging and discharging times of a capacitive element constituting the internal power supply.

[0006] For this purpose, one embodiment provides a device comprising: a generator adapted to produce electrical energy from a fluid flow through a body of the device; a capacitive element for storing the electrical energy produced; a switch connecting the capacitive energy storage element to a first electronic circuit and to the generator; and a second electronic circuit for controlling the switch to an open state when: a first voltage, supplied by the generator, is less than a first threshold; and a second voltage, present across the terminals of the capacitive element, is less than a second threshold.

[0007] According to one embodiment, the second circuit controls the closing of the switch when: the first voltage is greater than or equal to the first threshold; and the second voltage is greater than or equal to the second threshold.

[0008] According to one embodiment, the second circuit further controls a closing of the switch when: the first voltage is greater than or equal to the first threshold; and the second voltage is less than the second threshold.

[0009] According to one embodiment, the second electronic circuit comprises, in series between the generator and the capacitive element: - a series combination of a first resistive element and a second switch; and - a parallel association of a second resistive element and a third switch.

[0010] According to one embodiment, when the first voltage is greater than or equal to the first threshold, the third switch is activated: - towards an open state when the second voltage is greater than or equal to the second threshold and less than a third threshold; and - towards a closed state when the second voltage is greater than or equal to the third threshold.

[0011] According to one embodiment, the second electronic circuit is configured to recharge the capacitive element when the first voltage is greater than the first threshold.

[0012] According to one embodiment, the generator electrically supplies the first electronic circuit when the first voltage is greater than the first threshold.

[0013] According to one embodiment, the capacitive element is a supercapacitor.

[0014] According to one embodiment, the first electronic circuit includes a processing unit and a radio frequency communication circuit to the outside of the device.

[0015] According to one embodiment, the generator is further configured to estimate a flow rate of the fluid circulating through the body of the device.

[0016] According to one embodiment, the generator includes a turbine intended to be driven by the flow of fluid circulating through the body of the device.

[0017] One embodiment provides for a water meter comprising a device as described.

[0018] An embodiment provides a method for managing the energy of a device comprising: a generator adapted to produce electrical energy from a fluid flow through a body of the device; a capacitive element for storing the electrical energy produced; a switch connecting the capacitive energy storage element to a first electronic circuit and to the generator; and a second electronic circuit, the method comprising a step of controlling, by the second electronic circuit, the switch to an open state when: a first voltage, supplied by the generator, is less than a first threshold; and a second voltage, present across the terminals of the capacitive element, is less than a second threshold.

[0019] According to one embodiment, the process further includes a closing control step, by the second electronic circuit, of the switch when: the first voltage is greater than or equal to the first threshold; and the second voltage is greater than or equal to the second threshold. Brief description of the drawings

[0020] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the attached figures, among which:

[0021] Figure 1 represents, in a very schematic way and in block form, an example of a system of the type to which the described embodiments apply, by way of example;

[0022] Figure 2 represents, schematically and in block form, an embodiment of an electronic device integrating a power supply;

[0023] Figure 3 represents, schematically and in block form, one embodiment of an electronic device integrating a power supply;

[0024] Figure 4 is a detailed electrical diagram of an example implementation of the device in Figure 3;

[0025] Figure 5A is an electrical diagram equivalent to the device in Figure 4 in a first mode of operation;

[0026] Figure 5B is an electrical diagram equivalent to the device in Figure 4 in a second operating mode;

[0027] Figure 5C is an electrical diagram equivalent to the device in Figure 4 in a third operating mode;

[0028] Figure 5D is an electrical diagram equivalent to the device in Figure 4 in a fourth operating mode;

[0029] Figure 6 is a chronogram illustrating an example of how to implement the device shown in Figure 4;

[0030] Figure 7 schematically represents, in block form, another embodiment of an electronic device incorporating a power supply; and

[0031] Figure 8 is a chronogram partially illustrating an example of how to implement the device shown in Figure 7. Description of the implementation methods

[0032] The same elements have been designated by the same reference numerals in the different figures. In particular, structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0033] For the sake of clarity, only the steps and elements necessary for understanding the described implementations have been shown and detailed. In particular, the installation of water meters is not detailed in this description, as the implementations described are compatible with standard techniques for installing water meters on a water distribution network.

[0034] Unless otherwise specified, when referring to two connected elements, this means directly connected without any intermediate elements other than conductors, and when referring to two coupled elements, this means that These two elements can be connected or linked via one or more other elements.

[0035] In the description that follows, when referring to absolute positional qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative positional qualifiers, such as the terms "above", "below", "superior", "inferior", etc., or to orientational qualifiers, such as the terms "horizontal", "vertical", etc., unless otherwise specified, it refers to the orientation of the figures.

[0036] Unless otherwise specified, the expressions "approximately", "roughly", "about", and "on the order of" mean within 10%, preferably within 5%.

[0037] Figure 1 represents, in a very schematic way and in block form, an example of a system 100 of the type to which, by way of example, the described embodiments apply.

[0038] In the example shown, the system 100 includes an electronic device 101 (DEV1) with an internal or integrated power supply 103 (SC). The power supply 103 integrated into the device 101 can, for example, provide electrical power to one or more electronic circuits (not shown in Figure 1) of the device 101. In this example, the device 101 does not have an external power supply, such as a mains power grid. The power supply 103 is sized to meet the energy requirements of the components of the device 101, at least temporarily, for example, for several days, weeks, or months, without the need for other external power supplies.

[0039] In the illustrated example, the device 101 is mounted on, or connected to, a pipe 105, or conduit, through which a fluid, for example water, can flow (arrows 107). The device 101 is, for example, more precisely a water meter, one body of which (not detailed in Figure 1) is traversed by the flow 107 of water circulating in the pipe 105. Although not detailed in Figure 1, the device 101 is held securely to the pipe 105 by any suitable connecting element, including, for example, a mechanical retaining element such as a flange or fitting and a sealing element such as a gasket.

[0040] Optionally, the system 100 may also include, as illustrated in Figure 1, another electronic device 109 (DEV2) with which the device 101 can establish radio frequency communication. This radio frequency communication allows, for example, the device 101 to exchange data with the device 109. For instance, if the electronic device 101 is a water meter, data related to an estimate of the water flow rate in the pipe 105, an assessment of the water temperature, leak detection, etc., can be transmitted from the device 101 to the device 109. This allows, for example, a user of the device 101 to monitor the consumption of water supplied through the pipe 105. Furthermore, this can, for example, allow a water supplier to bill the user of the device 101 based on their water consumption.

[0041] Electronic devices 101 and 109 can communicate by any suitable means, using any common communication system or protocol, for example the LoRa, Sigfox, BLE (Bluetooth Low Energy), ZigBee, etc. protocol.

[0042] Figure 2 represents, schematically and in block form, an embodiment of the electronic device 101 (DEV1) of Figure 1 integrating the on-board power supply source 103 (SC).

[0043] According to this embodiment, the device 101 includes a power supply and conversion unit 201 (PLIM) adapted to generate electrical energy from the flow 107 (Figure 1) of the fluid through the body of the device 101. Although not detailed in Figure 2, the power supply and conversion unit 201 includes, for example, a turbine, driven in rotation by the circulation 107 of the fluid through the body of the device 101, and an alternator adapted to generate electrical energy from the rotation of the turbine. The electrical energy thus generated can be used to recharge the source 103 and / or to power the circuit 203. The rotation of the turbine in unit 201 can also be used to estimate the flow rate of the fluid circulating in the pipe 105.

[0044] In the example shown, the device 101 further includes a first electronic circuit 203 connected to the block 201 and comprising a processing unit 205 (pC), for example a microcontroller or a microprocessor, and an optional radio frequency communication circuit 207 (RF) to the outside of the device 101. The processing unit 205 is, for example, suitable for estimating the flow rate of the fluid passing through the body of the device 101 from an evaluation of the rotational speed of the turbine of the block 201 driven by the flow 107. According to another example, the unit 205 uses a volumetric measurement to estimate the flow rate. More generally, any suitable flow meter can be used by the processing unit. The optional radio frequency communication circuit 207 is, for example, suitable for establishing radio frequency communication between the device 101 and the device 109, as previously described in relation to figure 1.

[0045] In the example shown in Figure 2, device 101 also includes a second power management circuit 209 (PMIC). In this example, circuit 209 is connected to block 201, the power supply 103, and circuit 203. Circuit 209 is specifically designed to control: - the connection of the power supply source 103 to the block 201 and the electronic circuit 203, thus allowing energy to be transferred from or to the source 103; or - the electrical isolation of the source 103 from the block 201 and the circuit 203, thus allowing the blocking of electrical energy transfers between the source 103, on the one hand, and the block 201 and the circuit 203, on the other hand.

[0046] Device 101 may also include various other elements or circuits depending on the application. These elements and circuits are symbolized in Figure 2 by a single function block 211 (FCT). Function block 211 is, for example, powered by electrical energy from the power supply and conversion block 201. The elements and circuits of function block 211 may, as illustrated in Figure 2, be part of circuit 203. Alternatively, all or part of the elements and circuits of function block 211 are separate from circuit 203. Although not detailed in Figure 2, device 101 may also include one or more volatile and / or non-volatile storage areas, one or more data, address, and / or control buses between the various internal elements of device 101, and one or more input / output interfaces for communication with external devices, for example, sensors. temperature, pressure, humidity etc. and / or control of one or more solenoid valves.

[0047] Figure 3 represents, schematically and in block form, a more detailed embodiment of the electronic device 101 (DEV1) of Figure 2 incorporating the power supply 103. The optional radio frequency communication circuit 207 of the circuit 203 and the functional block 211 have not been illustrated in Figure 3 in order not to overload the drawing.

[0048] The embodiment illustrated in Figure 3 corresponds more precisely to a case where the power supply management circuit 209 (PMIC) is controlled by the processing unit 205 (pC). In Figure 3, the circuit 209 comprises a charging module 301 (CHG) and a discharging module 303 (DISCHG). The processing unit 205 controls the charging module 301 (arrow 305) and the discharging module 303 (arrow 307) of the circuit 209, for example, by means of control signals transmitted via links connecting the processing unit 205 to the charging modules 301 and 303. These control signals are, for example, generated by program code instructions executed by the processing unit 205.

[0049] The charging module 301 recharges the source 103 using electrical energy produced by the power supply and electrical conversion unit 201 when water flows through the pipe 105. The discharging module 303 discharges the source 103 to supply the circuit 203 when the water flow in the pipe 105 is insufficient for the circuit 203 to be supplied solely by the unit 201, for example, when the flow is practically zero. The discharging module 203 also protects the source 103 against discharges. "deep", for example discharges that could damage source 103.

[0050] The power supply 103 integrated into the device 101 is a capacitive element, preferably a capacitor, more preferably a supercapacitor. The power supply 103 has, for example, an electrical capacity that, in the absence of water circulation 107 in the piping 105 for several weeks or even several months, can power the treatment unit 205 and possibly the optional radio frequency communication circuit 207.

[0051] In general, source 103 is chosen and sized to mitigate, or compensate for, intermittent operation of block 201, including alternating: - initial phases during which water flows through pipe 105 at a sufficiently high flow rate to allow the generator to supply circuit 203; and - second phases during which the water does not flow in the pipe 105, or flows at an insufficient speed to allow the block 201 to produce the electrical energy required to power the circuit 203.

[0052] In other words, source 103 allows to "take over" the power supply of device 101 during the second phases where circuit 203 cannot be powered by block 201 alone.

[0053] In the example illustrated in Figure 3, the power supply and conversion block 201 includes a generator 308 (EH) and a circuit 309 (REG) for regulating the electrical energy produced by the generator 308. The generator 308 of the block 201 includes, for example, the turbine, driven in rotation by the circulation 107 of the fluid through the body of the device 101, and the alternator adapted to produce electrical energy from the rotation of the turbine. The circuit 309 includes, for example, a converter of voltage and a step-down module, as will be explained in more detail below with reference to Figure 7. Circuit 309 is connected in series with a unidirectional conduction element 311 from block 201 to processing unit 205 and supercapacitor 103, for example, a diode whose anode is connected to an output of circuit 309 and whose cathode is connected to a node 313 for applying a potential Vdd. The potential Vdd corresponds, for example, to a supply voltage provided by generator 308. Advantageously, a diode with the lowest possible reverse current is chosen.

[0054] In this example, circuit 209 is connected between node 313 and another node 315, which applies a potential Vsc. Supercapacitor 103 is connected between node 315, which applies the potential Vsc, and yet another node 317, which applies a reference potential, for example, ground. The potential Vsc is a function of the voltage across supercapacitor 103. Processing unit 205 is connected between node 313 and node 317, which apply the reference potential.

[0055] As illustrated in Figure 3, the discharge module 303 of the supercapacitor 103 can further be controlled (arrow 319) according to the potential Vsc present at node 315 as will be explained in more detail below.

[0056] Figure 4 is a detailed electrical diagram of an example implementation of the device in Figure 3.

[0057] In the example shown in Figure 4, the load module 301 comprises a resistive element RI, or resistor, and a switch Cl connected in series between node 313 and another node 401. The switch Cl preferably has a low on-state resistance compared to the resistance of the resistive element RI. The load module 301 further comprises another resistive element R2, or resistor, and another Switch C2 is connected in parallel between node 401 and another node 403. Switch C2 preferably has a low on-state resistance compared to the resistance of the resistive element RI. In the example shown, the processing unit 205 (pC) applies a control signal CMD1 to a control terminal of switch C1 and another control signal CMD2 to a control terminal of switch C2.

[0058] The resistive element R2 may have a higher or lower resistance than the resistive element RI. The resistance of element R2 is chosen empirically, based on the electrical characteristics of the supercapacitor 103, the resistive characteristics of the overall circuit, and the power levels involved. For example, resistive elements RI and R2 have resistances of approximately 10 Ω and 42 Ω, respectively.

[0059] In this example, the discharge module 303 includes yet another C3 switch connected between nodes 403 and 315. The C3 switch has a control terminal on which the processing unit 205 applies yet another CMD3 control signal.

[0060] As an example, each CMD1, CMD2, CMD3 signal is a binary signal whose first state, for example a high state, allows to control a closure of the corresponding switch Cl, C2, C3 and whose second state, the low state in this example, allows to control an opening of the corresponding switch Cl, C2, C3.

[0061] The discharge module 303 further includes a module 405 for protecting the supercapacitor 103. More specifically, module 405 protects the supercapacitor 103 against so-called "deep" discharges, for example, discharges that could damage the supercapacitor 103. For instance, module 405 prevents the potential Vsc at node 315 from dropping to below a minimum charge threshold (Vsc_min), or maximum discharge threshold, below which the supercapacitor 103 risks being damaged. In practice, a safety margin can be provided, the Vsc_min threshold thus being higher, for example by a few tenths of a volt, than the actual damage threshold of the supercapacitor 103.

[0062] In the example shown in Figure 4, the 405 module protecting supercapacitor 103 is connected, via a resistor R3, to the control terminal of switch C3. The 405 module applies a CMD4 control signal to the control terminal of switch C3. The 405 module is also connected to nodes 315 and 317. As an example, the CMD4 signal is a binary signal whose first state, for example, high, controls the closing of switch C3, and whose second state, for example, low, controls the opening of switch C3.

[0063] For example, the CMD3 signal has priority over the CMD4 signal. This allows the processing unit 205, when the power supplied by the generator 308 is sufficient to recharge the source 103, to force the closure of the switch C3 in a case where the potential Vsc is less than the threshold Vsc_min.

[0064] In the example shown, the discharge module 303 further includes another unidirectional conduction element 407, for example a diode whose anode is connected to node 403 and whose cathode is connected to node 313. The diode 407 allows current to flow from node 403 to node 313 while preventing current from flowing from node 313 to node 403 without passing through the recharge module 301.

[0065] The operation of device 101 in Figure 4 will now be described in more detail in relation to Figures 5A to 5D.

[0066] Figure 5A is an electrical diagram equivalent to device 101 in Figure 4 in a first operating mode corresponding to a case where the potential Vdd is greater than or equal to a threshold Vdd_min and where the potential Vsc is between the threshold Vsc_min and another threshold Vsc_fch.

[0067] The Vdd_min threshold corresponds more precisely to a threshold beyond which the generator 308 is considered to provide sufficient energy to power the circuit 203. The Vsc_fch threshold, for example, is between the minimum charge threshold Vsc_min and the maximum charge threshold Vsc_max of the supercapacitor 103. As an example, the Vsc_min and Vsc_max thresholds have values ​​of approximately 2.7 V and 3.6 V, respectively. The value of the Vsc_fch threshold is determined, for example, based on the generator 308 and the internal resistances of the device 101. As an example, the Vsc_fch threshold has a value of approximately 3.1 V.

[0068] In the first operating mode, switch C1 is closed while switch C2 is open. The load module 301 then has a resistance Rmax that corresponds approximately to the series combination of resistances R1 and R2 (Rmax = R1 + R2), excluding the parasitic resistance of switch C1. In this operating mode, switch C3 is closed, and the discharge module 303 thus has a closed circuit.

[0069] The resistance Rmax is chosen for example so as to allow the generator 308 of the device 101 to recharge the supercapacitor 103 while electrically supplying the processing unit 205, the unit 205 remaining further supplied by the supercapacitor 103.

[0070] Figure 5B is an equivalent electrical circuit for device 101 in Figure 4 in a second operating mode corresponding to a case where the potential Vdd is greater than or equal to the threshold Vdd_min and where the potential Vsc is between the thresholds Vsc_fch and Vscjnax.

[0071] In the second operating mode, switches C1 and C2 are closed. The load module 301 then has a resistance Rmin lower than the resistance Rmax, for example, approximately equal to the resistance RI, excluding the parasitic resistances of switches C1 and C2. In this operating mode, switch C3 is closed, and the discharge module 303 thus has a closed circuit, excluding the parasitic resistance of switch C3.

[0072] Figure 5C is an electrical equivalent diagram of device 101 in Figure 4 in a third operating mode corresponding to a case where the potential Vdd is strictly less than the threshold Vdd_min and where the potential Vsc is greater than or equal to the threshold Vsc_min.

[0073] In the third operating mode, switches C1 and C2 are open. The load module 301 then functions as an open circuit. In this operating mode, switch C3 is closed, and the discharge module 303 thus functions as a closed circuit.

[0074] This allows the supercapacitor 103 to maintain the power supply to the processing unit 205, for example when the rotational speed of the turbine of the generator 308 is zero or insufficient to allow a potential greater than or equal to Vdd to be applied at node 313.

[0075] In this operating mode, the radio frequency communication circuit 207 (Figure 2) can also be powered, at least periodically, by the supercapacitor 103. For example, this allows the device 101 to transmit data to the device 109, for example under message formats, each containing one or more pieces of data chosen from: - a message identifier; - a water temperature in the pipe of 105; - a cumulative volume of water having circulated, for a first period, through the body of device 101; - the first duration; - a second duration corresponding for example to a time elapsed between an initial moment and a moment of transmission of the message; - a flow rate estimate; and - a charge level of the supercapacitor 103, for example image of the potential Vsc present at node 315.

[0076] The second duration is used for example by device 109 to timestamp the moment of generation of the message relative to a time reference, for example a universal clock of device 109 in Figure 1, as a function of a transmission moment of this message.

[0077] Figure 5D is an equivalent electrical circuit for device 101 in Figure 4 in a fourth operating mode corresponding to a case where the potential Vsc is strictly less than the threshold Vsc_min. Furthermore, the fourth operating mode corresponds to: - to a first PHI phase in which the potential Vdd is lower than the threshold Vdd_min, the processing unit 205 not being powered in this case; or - to a second transient phase PH2, covering the transition from the first phase to the first operating mode, in which the potential Vdd is greater than the threshold Vdd_min, the processing unit 205 being powered in this case, and in which the closing of switch Cl has not yet been commanded. The transient phase PH2, of very short duration compared to the phase PHI, corresponds for example to a situation in which fluid begins to circulate again after a long period of inactivity.

[0078] In the fourth operating mode, switches C1, C2, and C3 are open. The charging module 301 and the discharging module 303 are therefore each equivalent to an open circuit. The supercapacitor 103 is then isolated from the other elements of device 101. This prevents deep discharge of the supercapacitor 103, for example, after a prolonged period of inactivity of the generator 308, which could last several weeks or even several months.

[0079] Figure 6 is a chronogram illustrating an example of the implementation of device 101 of Figure 4. Figure 6 more precisely illustrates a curve 601 of evolution, as a function of time t (on the x-axis) of the potential Vsc (on the y-axis) present at node 315 of device 101.

[0080] At time t0, the potential Vdd applied to node 313 is greater than the threshold Vdd_min (Vdd h Vdd_min) and the potential Vsc is approximately equal to the threshold Vsc_min. Device 101 is then in the first operating mode (MODE1). The supercapacitor 103 is recharged by the generator 308, which causes an increase in the potential Vsc present at node 315.

[0081] At another time t1, after time t0, the potential Vsc crosses the threshold Vsc_fch while the potential Vdd applied to node 313 remains above the threshold Vdd_min. Device 101 is then in the second operating mode (MODE2). Switch C2 is closed when the potential Vsc reaches the threshold Vsc_fch. This causes an acceleration in the charging of the supercapacitor 103, due to the fact that the supercapacitor 103 is now charged not through the resistance Rmax, as in the first operating mode, but through the resistance Rmin. This acceleration results in a sharp increase in slope of curve 601 in relation to another curve 603 (dotted line) symbolizing the evolution of the potential Vsc if switch C2 were not closed at time tl. Curve 601 more precisely shows an inflection point at time tl. Commanding the closure of switch C3 at time tl advantageously reduces the charging time of supercapacitor 103 while continuing to power the processing unit 205, which also remains powered by supercapacitor 103.

[0082] At yet another time t2, subsequent to time t1, the potential Vdd applied to node 313 becomes strictly less than the threshold Vdd_min (Vdd < Vdd_min) while the potential Vsc is approximately equal to the maximum charging threshold Vsc_max of the supercapacitor 103. Device 101 is then in the third operating mode (MODE3). Switches C1 and C2 are open and switch C3 is closed to allow the supercapacitor 103 to power the processing unit 205 on its own.

[0083] At yet another time t3, subsequent to time t2, the potential Vsc becomes strictly below the threshold Vsc_min, while the potential Vdd applied to node 313 remains strictly below the threshold Vdd_min. Device 101 is then in the fourth operating mode (MODE4), more precisely in the first phase PHI where the processing unit 205 is not powered. Opening switch C3 then protects the supercapacitor 103 against deep discharge.

[0084] As an example, at yet another time t4 after time t2, the potential Vdd applied to node 313 becomes greater than the threshold Vdd_min and device 101 is then brought back into the first operating mode after the transient phase PH2.

[0085] The table below summarizes the different operating modes MODE1, MODE2, MODES, and MODE4 of device 101 in Figure 4. In this table, for each of the switches C1, C2, and C3, the letter F indicates a closed state and the letter O an open state. Furthermore, the abbreviation "Supercond." designates the supercapacitor 103. It should be noted that, in the third and fourth modes MODES and MODE4, the state of switch O2 is irrelevant since switch C1 is open.

[0086] [Table 1]

[0087] Device 101 in Figure 4 and the implementation method described above in relation to Figure 6 have the advantage of allowing optimization of the charging and discharging times of the supercapacitor 103.

[0088] Figure 7 schematically represents, in block form, another embodiment of an electronic device 701 incorporating a power supply. The device 701 illustrated in Figure 7 corresponds to a more detailed embodiment of the electronic device 101 of Figure 2, incorporating the power supply 103 in a case where the power supply control by the supercapacitor 103 is operated by a logic circuit, for example, independent of the processing unit 205. The optional radio frequency communication circuit 207 of the circuit 203 and the functional block 211 were not illustrated in figure 3 in order to avoid overloading the drawing.

[0089] Device 701 in Figure 7 includes elements in common with device 101 in Figure 3. These common elements will not be detailed again below.

[0090] Circuit 309 of block 201 of device 701 includes a converter 703 (CONV), for example an AC-DC converter, which produces a DC output voltage Vdc from an AC input voltage Vac supplied by generator 308 (EH). Circuit 309 also includes a step-down module 705 (VSD) which, from the input voltage Vdc, provides a lower output voltage, for example, compatible with a range of supply voltages for the processing unit 205 (pC). In the illustrated example, module 705 applies a potential Vin to a node 707 of device 701. The potential Vin corresponds, for example, to a supply voltage provided by generator 308. Circuit 309 of device 101 in Figures 3 and 4 is, for example, identical or analogous to circuit 309 of device 701 in Figure 7.

[0091] In the example shown, the anode of the unidirectional conduction element 311 is connected to node 707, and the cathode of element 311 is connected to node 711, which applies a potential Vcc. In this example, the processing unit 205 is connected to node 711 and is powered by the potential Vcc.

[0092] Circuit 209, in the embodiment illustrated in Figure 7, comprises a first logic block 713 (Vin > Vin_min: H; Vin < Vin_min: L) whose input is connected to node 707 and whose output transmits a binary logic signal LSI to an input of an inverting logic gate 715. The logic signal LSI is in a first state, for example The signal is in a high state (H) when the potential Vin at node 707 is greater than or equal to a threshold Vin_min, and in a low state (L) in this example when the potential Vin is strictly less than the threshold Vin_min. The inverter gate 715 provides a binary logic signal LS2 at its output. The LS2 signal is in a high state (H) when the signal LSI is low (L), and in a low state (L) in this example when the signal LSI is high (H). The minimum threshold Vin_min corresponds, for example, more precisely to a threshold beyond which the generator 308 is considered to provide sufficient power to supply the circuit 203. As an example, the threshold Vin_min is approximately 3.1 V.

[0093] Circuit 209 also includes another logic block 717 (Vsc < Vsc_min: H; Vsc h Vsc_min: L) whose input is connected to node 315, which applies the potential Vsc, and whose output provides a binary logic signal LS3. The logic signal LS3 is in a first state, for example a high state H, when the potential Vsc present at node 315 is strictly less than the threshold Vsc_min, and in a second state, the low state L in this example, when the potential Vsc is greater than or equal to the threshold Vsc_min.

[0094] Signals LS2 and LS3, originating from inverting logic gate 715 and logic block 717 respectively, are passed to a NAND (&) logic gate 719. The NAND logic gate 719 outputs a binary logic signal Vsw applied to a control input of a switch 04. In the example shown in Figure 7, switch 04 is connected to node 711, which applies the potential Vcc, and node 315, which applies the potential Vsc. A first state, for example a high state H, of the signal Vsw controls the closing of switch 04, and a second state, the low state L in this example, controls the switching. the opening of switch 04. In this example, switch C4 is open when the potentials Vsc and Vin are below the thresholds Vsc_min and Vin_min, respectively, and closed in other cases.

[0095] The table below summarizes the different operating modes of device 101 in Figure 7. In this table, the letter H indicates a high state of the signal Vsw, LSI, LS2, or LS3, and the letter L indicates a low state. Furthermore, the abbreviation "Supercond." refers to the supercapacitor 103.

[0096] [Table 2]

[0097] Figure 8 is a chronogram partially illustrating an example of the implementation of device 701 in Figure 7. Figure 8 more precisely illustrates curves 801, 803 and 805 of evolution, as a function of time t (abscissa) of the potential Vin, the potential Vsc and a supply current I of the supercapacitor 103 (ordinate).

[0098] At time t0, the potentials Vin and Vsc are respectively equal to the thresholds Vin_min and Vsc_min. Switch C4 is closed, and the supercapacitor 103 begins to be recharged by generator 308. The supply current I to the supercapacitor 103 then reaches a maximum value Isat. Between time t0 and another time tl, subsequent to time t0, the potentials Vin and Vsc increase while the current I remains approximately equal to the maximum value Isat. This is because, between times t0 and tl, the supercapacitor 103 has a current demand greater than what generator 308 is able to supply. As an example, the maximum value Isat, or saturation value, of the current I is approximately 40 mA.

[0099] From time t1, generator 308 produces a current exceeding the demand of supercapacitor 103. The current I then begins to decrease while the potential Vin increases, reaching, at yet another time t2 after time t1, a threshold higher than Vin_max. As an example, the threshold Vin_max is approximately 4 V.

[0100] At time t3, later than time t2, the potential Vsc reaches the maximum threshold Vsc_max and the supply current I of the supercapacitor 103 reaches a minimum threshold, for example, practically zero. The potential Vin remains, between times t2 and t3, practically constant and equal to approximately Vin_max.

[0101] The device 701 of figure 7 and the implementation method described above in relation to figure 8 advantageously allow for the optimization of the charging and discharging times of the supercapacitor 103.

[0102] One advantage of the embodiments of devices 101 and 701 described previously in relation to Figures 4 and 7 is that they allow the circuit to be powered 203 in electrical energy, by the supercapacitor 103, during periods of inactivity of the generator 308. In addition, the supercapacitor 103 can advantageously be recharged during periods of operation of the generator 308, thus avoiding the need for the user of devices 101 and 701 to perform replacement or recharging operations on the energy source integrated into the device. The supercapacitor 103 of devices 101 and 701 is also protected against deep discharge.

[0103] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will be apparent to them. In particular, what is presented specifically in relation to an application example for an electronic water meter applies more generally to any electronic device that includes an integrated power supply.

[0104] Finally, the practical implementation of the described embodiments and variants is within the grasp of a person skilled in the art, based on the functional specifications given above. In particular, a person skilled in the art is able to adapt the described embodiments to a case where the first and second states of the binary signals are low and high, respectively.

Claims

Tl CLAIMS Device (101; 701) comprising: a generator (308) adapted to produce electrical energy from a circulation (107) of fluid through a body of the device; a capacitive element (103) for storing the electrical energy produced; a switch (C3; C4) connecting the capacitive energy storage element to a first electronic circuit (203) and to the generator; and a second electronic circuit (209) for controlling the switch to an open state when: a first voltage (Vdd; Vin), supplied by the generator, is less than a first threshold (Vdd_min; Vin_min); and a second voltage (Vsc), present across the terminals of the capacitive element, is less than a second threshold (Vsc_min).A device according to claim 1, wherein the second circuit (209) controls the closing of the switch (C3; C4) when: the first voltage (Vdd; Vin) is greater than or equal to the first threshold (Vdd_min; Vin_min); and the second voltage (Vsc) is greater than or equal to the second threshold (Vsc_min). A device according to claim 1 or 2, wherein the second circuit (209) further controls the closing of the switch (C3; C4) when: the first voltage (Vdd; Vin) is greater than or equal to the first threshold (Vdd_min; Vin_min); and the second voltage (Vsc) is less than the second threshold (Vsc_min). Device according to any one of claims 1 to 3, wherein the second electronic circuit (209) comprises, in series between the generator (308) and the capacitive element (103): - a series combination of a first resistive element (RI) and a second switch (Cl); and - a parallel combination of a second resistive element (R2) and a third switch (C2). Device according to claim 4, wherein, when the first voltage (Vdd; Vin) is greater than or equal to the first threshold (Vdd_min; Vin_min), the third switch (C2) is activated: - towards an open state when the second voltage (Vsc) is greater than or equal to the second threshold (Vsc_min) and less than a third threshold (Vsc_fch); and - to a closed state when the second voltage is greater than or equal to the third threshold. Device according to any one of claims 1 to 3, wherein the second electronic circuit (209) is configured to recharge the capacitive element (103) when the first voltage (Vin) is greater than the first threshold (Vin_min). Device according to claim 6, wherein the generator (308) electrically supplies the first electronic circuit (203) when the first voltage (Vin) is greater than the first threshold (Vin_min). Device according to any one of claims 1 to 7, wherein the capacitive element is a supercapacitor. Device according to any one of claims 1 to 8, wherein the first electronic circuit (203) comprises a processing unit (205) and a circuit (207) of radio frequency communication to the outside of the device (101; 701). . Device according to any one of the claims 1 to 9, wherein the generator (308) is further configured to estimate a flow rate of the fluid circulating through the body of the device (101; 701). Device according to any one of claims 1 to 10, wherein the generator (308) comprises a turbine intended to be driven by the flow (107) of fluid circulating through the body of the device (101; 701). Water meter comprising a device (101; 701) according to any one of claims 1 to 11.Energy management method of a device (101; 701) comprising: a generator (308) adapted to produce electrical energy from a circulation (107) of fluid through a body of the device; a capacitive element (103) for storing the electrical energy produced; a switch (C3; C4) connecting the capacitive energy storage element to a first electronic circuit (203) and to the generator; and a second electronic circuit (209), the method comprising a step of controlling, by the second electronic circuit, the switch to an open state when: a first voltage (Vdd; Vin), supplied by the generator, is less than a first threshold (Vdd_min; Vin_min); and a second voltage (Vsc), present across the terminals of the capacitive element, is less than a second threshold (Vsc_min). Method according to claim 13, further comprising a closing control step, by the second electronic circuit (209), of the switch (C3; C4) when: the first voltage (Vdd; Vin) is greater than or equal to the first threshold (Vdd_min; Vin_min); and the second voltage (Vsc) is greater than or equal to the second threshold (Vsc_min).

Images