Circuit arrangement for extracting energy from an energy harvester

Abstract

A circuit arrangement for extracting energy from an energy harvester is proposed. The circuit arrangement (1) comprises an integrated circuit (3) connected to the energy harvester (2) and configured to extract energy from the energy harvester, an energy accumulator (4) connected to the integrated circuit for receiving said energy extracted by the integrated circuit, and a switch (5) arranged between the integrated circuit and the energy accumulator for selectively disconnecting the accumulator from the integrated circuit (3). The integrated circuit (3) is configured to output a control signal, said control signal being either inverting or non-inverting and configured to close the switch (5) when the integrated circuit is able to extract energy from the energy harvester (2) and to open the switch when the integrated circuit (3) is not able to extract energy from the energy harvester (2), to thereby disconnect the integrated circuit from the accumulator (4).

Description

Technical Field

[0001] This utility model relates to a circuit layout structure for use in an energy harvesting system to reduce energy consumption in the system. It also relates to an operating circuit layout structure for a method of extracting energy from an energy harvester to charge an energy storage device in the energy harvesting system. Background Technology

[0002] In an era of ubiquitous computing and ever-growing demand for portable electronic devices, energy harvesting has emerged as a key technology for providing sustainable power sources. Energy harvesters utilize ambient energy from the environment, such as solar radiation, vibration, or thermal gradients, and convert it into electrical power. Regardless of the prospects for energy harvesting, the efficiency of power extraction remains a critical consideration.

[0003] When applied to watches, the advantage of energy harvesters is that they can reduce or eliminate the need for battery replacements, making them more sustainable and environmentally friendly. However, the amount of energy that can be harvested depends on factors such as the type of harvester, environmental conditions, and the watch's power requirements. With technological advancements, we can expect to see more watches and other electronic devices incorporating energy harvesting technology.

[0004] A significant obstacle to optimizing energy harvesting systems is the energy consumption of the integrated circuits (ICs) responsible for extracting and managing the harvested energy. These ICs play a crucial role in making energy harvesting systems practical and efficient, especially in applications such as wearable devices where space and power constraints are significant considerations. Advances in dedicated energy harvesting ICs have contributed to the development of self-powered and energy-efficient electronic devices. Traditional approaches to ICs often neglect the important aspect of minimizing the power requirements of these circuits, leading to inefficiencies that negatively impact the overall efficiency of the energy harvesting system. Excessive energy consumption not only reduces net energy gain but also imposes constraints on the feasibility of deploying energy harvesters in resource-constrained applications. In systems using dedicated ICs for external energy harvesting functions, the IC continues to consume energy even in the absence of external power. This reduces the system's autonomy and power reserves, as the IC is powered by the system's energy storage, such as a battery. Utility Model Content

[0005] The purpose of this invention is to overcome the aforementioned drawbacks associated with integrated circuits used to extract energy from energy harvesters. This invention therefore focuses on overcoming energy consumption bottlenecks by proposing an electronic circuit arrangement, also referred to as a circuitry or electronic circuit system, specifically engineered to be exceptionally energy-efficient in the context of energy extraction from harvesters. The proposed circuit arrangement is designed to operate with minimal power overhead, ensuring that the energy consumed by the integrated circuit is significantly lower than that of conventional circuit systems.

[0006] According to a first aspect of the present invention, a circuit layout structure for extracting energy from an energy harvester is provided.

[0007] The circuit arrangement structure according to the first aspect of this utility model includes:

[0008] - An integrated circuit that is connected to an energy harvester and configured to extract energy from the energy harvester;

[0009] - An energy storage device configured to be connected to an integrated circuit for receiving energy extracted by the integrated circuit;

[0010] - A switch, positioned between the integrated circuit and the energy storage device, selectively disconnects the energy storage device from the integrated circuit.

[0011] The integrated circuit is configured to output a control signal such that the inverted or non-inverted control signal is configured to close the switch when the integrated circuit can extract energy from the energy harvester, and to open the switch when the integrated circuit cannot extract energy from the energy harvester, thereby disconnecting the integrated circuit from the energy storage device.

[0012] The circuit layout also includes a load, which is powered by and connected to the energy storage device, such that the load is not connected to the energy storage device via an integrated circuit.

[0013] In the circuit layout described above, the load is directly connected to the energy storage device.

[0014] In the circuit layout described above, the load includes a watch system.

[0015] The circuit layout also includes logic circuitry, which is arranged between the integrated circuit and the switch to process control signals to be applied to the switch.

[0016] In the circuit layout described above, the logic circuit is an inverter circuit using complementary metal-oxide-semiconductor circuitry.

[0017] In the circuit layout described above, the switch is a P-channel metal-oxide-semiconductor field-effect transistor.

[0018] In the circuit layout described, the integrated circuit includes a stored energy storage element or the integrated circuit is connected to the stored energy storage element to help power the integrated circuit after it is powered off, so that it can extract energy from the energy harvester.

[0019] In the circuit layout described above, the energy storage element is a short-term storage capacitor.

[0020] In the circuit layout described above, the integrated circuit cannot be powered by the energy storage device when the switch is turned on.

[0021] In the circuit layout described above, the circuit layout further includes a boost circuit, which is configured to increase the voltage level present at the output node of the energy harvester.

[0022] In the circuit layout described above, the control signal is characterized by a high signal value when the integrated circuit can extract energy from the energy harvester, and by a low signal value when the integrated circuit cannot extract energy from the energy harvester.

[0023] In the circuit arrangement described, the energy harvester is at least one of the following: a solar cell, a kinetic or mechanical energy storage device, a thermoelectric generator, a radio frequency harvester, and / or wherein the energy storage device is a rechargeable battery and / or a supercapacitor.

[0024] This invention offers the following advantages: it provides increased system autonomy and power reserves while maintaining the ability of integrated circuits within the circuit layout to optimally harvest energy from external sources. Furthermore, the circuit layout not only maximizes the net energy available for consumption but also extends the operational lifespan of the energy harvesting system, making them more practical and sustainable across a wide range of applications.

[0025] According to a second aspect of the present invention, a method is provided for operating a circuit layout structure for extracting energy from an energy harvester.

[0026] Other aspects of this invention are set forth in the dependent claims appended herein. Attached Figure Description

[0027] Other features and advantages of the present invention will become apparent from the following description of non-limiting exemplary embodiments, with reference to the accompanying drawings, in which:

[0028] Figure 1This is a block diagram illustrating an energy harvesting system according to an exemplary embodiment of the present invention;

[0029] Figure 2 It is shown Figure 1 The circuit diagram of an example implementation of an energy harvesting system is shown in the figure; and

[0030] Figure 3 It is a diagram. Figure 1 The flowchart shows the operation of the energy harvesting system. Detailed Implementation

[0031] Embodiments of the present invention will now be described in detail with reference to the accompanying figures. The present invention will be described in the context of an energy harvesting system for a timepiece (such as a watch). However, the teachings of the present invention are not limited to that environment or application. Identical or corresponding functional and structural elements appearing in different figures are assigned the same reference numerals. As utilized herein, “and / or” means any one or more entries in a list linked by “and / or”. As an example, “x and / or y” means any element in the three-element set {(x), (y), (x, y)}. In other words, “x and / or y” means “one or both of x and y”. As another example, “x, y and / or z” means any element in the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, “x, y and / or z” means “one or more of x, y and z”. Furthermore, the term “comprising” is used herein as an open-ended term. This means that the object encompasses all the listed elements, but may also include additional unnamed elements. Therefore, the word "includes" is interpreted in a broader sense as "including," "containing," or "encompassing."

[0032] Figure 1 This is a block diagram illustrating an example energy harvesting system 1 according to the present invention. Figure 1 The arrows indicate the direction of energy flow. An energy harvesting system includes an energy source or harvester 2. An energy harvester for a watch is a device that captures ambient energy from the environment and converts it into electrical power to power the watch. Traditional watches often use batteries for power, but energy harvesters provide an alternative or supplementary energy source. One or more types of energy harvesters can optionally be used in combination, and they can utilize different ambient energy sources, including:

[0033] - Solar Panel: Watches equipped with a solar panel can convert solar energy, typically from the sun, into electrical power. The solar panel is usually integrated into the dial.

[0034] - Kinetic or mechanical energy harvesters: These devices convert kinetic or dynamic energy into electrical power. In the case of watches, this often involves using a rotor that rotates with the movement of the wearer's wrist to generate electrical energy.

[0035] - Thermoelectric generators: These collectors convert temperature differences into electrical power. The temperature gradient between the wearer's body and the surrounding environment can be used to generate energy.

[0036] - Radio Frequency (RF) Harvester: An RF harvester captures energy from surrounding radio frequency signals. This technology is still in its early stages, but it has the potential to be used in small electronic devices such as watches.

[0037] Energy harvester 2 is connected to energy harvester IC 3, which is a component designed to extract energy from the energy harvester and manage and optimize this operation, as well as the subsequent processing of the extracted energy. An IC is a component of electronic parts, typically hundreds to millions of transistors, resistors, and capacitors interconnected and built on a thin substrate of semiconductor material (usually silicon) to form a small chip or wafer. It should be noted that in this description, the expression "operably coupled" can be used synonymously with the word "connected." The primary function of IC 3 is to efficiently convert and regulate the harvested energy to charge energy storage 4. The features and functions of IC 3 may include one or more of the following:

[0038] - Energy Harvesting Control: The IC monitors the output of the energy transducer (e.g., the voltage from the energy harvester) and controls the harvesting process to maximize efficiency.

[0039] - Power Management: The IC manages the power generated by the energy harvester, ensuring it is delivered to the energy storage unit 4 in a stable and regulated manner. This may include voltage regulation, current limiting, and other power management features.

[0040] - Energy storage interface: IC facilitates the charging of energy storage device 4, which can be a rechargeable battery or a capacitor.

[0041] - Low-power operation: Because energy harvesting applications often involve small amounts of available power, the IC is designed to operate efficiently at low power levels. This can include zero-power or virtually zero-power sleep modes.

[0042] - Adaptive power control: ICs can have adaptive power control features, adjusting power delivery based on the energy availability and power requirements of components in the energy harvesting system.

[0043] - Energy Monitoring and Reporting: The IC may include features for monitoring and reporting energy harvesting performance. This information can be valuable for optimizing the design and understanding the device's energy budget.

[0044] The energy harvesting system 1 includes an energy accumulator 4, which is an energy storage element. In the context of a watch, the energy accumulator is therefore a component used for energy storage. The energy accumulator can be, for example, a rechargeable battery, such as a lithium-ion or lithium-polymer battery. Alternatively or additionally, the energy accumulator can be a supercapacitor, also known as an ultracapacitor, which is a high-capacitance capacitor with a much higher capacitance value than a solid-state capacitor but with a lower voltage limit. It bridges the gap between electrolytic capacitors and rechargeable batteries. It typically stores 10 to 100 times more energy per unit volume or mass compared to an electrolytic capacitor, can accept and transfer charge much faster than a battery, and withstands more charge and discharge cycles than a rechargeable battery. The energy accumulator 4 thus acts as a reservoir for storing the harvested energy. The energy production from the energy harvester may not be constant or may not match the watch's immediate power needs. The energy accumulator allows the watch to store additional energy during periods of ample supply and release it when needed to power the watch's electronic components.

[0045] According to this invention, the energy storage device 4 is connected to the IC 3 via a switch 5, which is configured to be selectively closed or opened based on the IC 3's ability to extract energy from the energy harvester 2. More specifically, the IC 3 is configured to output a control signal, which may also be referred to as an energy signal, and an inverted or non-inverted control signal is used to control the operation of the switch. In other words, the control signal is used to control the electrical conduction of the switch. If the energy harvester is unable to harvest energy, the control signal (or its absence) is arranged to disconnect the IC 3 from the energy storage device 4. In other words, if the IC cannot extract energy from the energy harvester 2, the switch 5 is open (i.e., not electrically conductive). Once the energy harvester is able to harvest energy, or once the IC can extract energy from the energy harvester 2, the switch 5 is closed, i.e., it becomes electrically conductive, allowing the IC to charge the energy storage device. When the IC 3 is disconnected from the energy storage device 4, it no longer consumes energy, or its energy consumption is substantially negligible. When the IC is connected to the energy storage device, the IC's energy consumption is covered by the energy extracted from the harvester, and any additional energy is used to charge the energy storage device. It's important to note that instead of just one switch between IC 3 and the energy storage device 4, multiple switches can be provided to form a switching system. In this case, these switches will be operated in a controlled manner to jointly disconnect the IC from the energy storage device or jointly connect IC 3 to the energy storage device 4 based on one or more control signals from IC 3.

[0046] Control signals can be digital or analog. In this description, the term "signal" is to be broadly understood as meaning that certain information is typically encoded in a signal. Figure 2 In the example, analog signals are used. When IC 3 is able to extract energy from energy harvester 2, its first output node or terminal 6 (in...) Figure 2 The voltage value (referred to as VSUP) is set to a high voltage value V. DD And when it is unable to extract energy from the energy harvester, it is set to a low voltage value V. SS V SS In this case, it is zero.

[0047] In this example, switch 5 is implemented as a transistor, and more specifically as a p-type metal-oxide-semiconductor field-effect transistor. To close the p-MOSFET switch, a low voltage needs to be applied to the gate terminal of the PMOS transistor in such a way that the voltage between the gate and source terminals is negative. When a low voltage (lower than the source voltage) is applied to the gate terminal of the PMOS transistor, the PMOS transistor operates by creating a conductive channel between the source and drain terminals. In this case, the voltage difference between the gate and source (V...) gs When the value is negative, the PMOS transistor is turned on and current is allowed to flow from the source to the drain. For this reason, the energy harvesting system 1 also includes logic circuit 7 in this case. Logic circuit 7 can be an inverter circuit, also known as a signal inverter, which is arranged between IC 3 and switch 5 to invert the control signal, and then the inverted control signal is applied to the switch.

[0048] Figure 1 The watch system 8 is further illustrated. The watch system 8 can be understood as part of the energy harvesting system 1, or alternatively, it can be understood as a system that is not part of the energy harvesting system but is connected to it. The watch system forms the load of the energy harvesting system and includes the electronic components of the watch powered by the energy storage device. For this reason, the watch system is connected to the energy storage device, as shown in... Figure 1 As shown in the diagram. In particular, unlike in conventional energy harvesting systems, in this case, the watch system 8 is directly connected to the energy storage unit, so that the watch system is not connected to the energy storage unit through IC3.

[0049] Figure 2 It is shown Figure 1The circuit diagram shows some example implementation details of the energy harvesting system 1. More specifically, the energy harvesting system 1 and IC 3 further include a stored energy storage element 9, which in this example is a capacitor, referred to as the first capacitor. In this example, the first capacitor is a short-term storage capacitor used to temporarily store electrical energy. The purpose of the first capacitor is to help IC 3 autonomously power itself when it is not connected to the energy storage device 4. With the first capacitor 9, the IC thus has a sufficient internal capacity to autonomously power itself for short periods. In other words, the IC is able to autonomously power itself using only the energy provided by the energy harvester 2 and the first capacitor 9. Therefore, IC 3 is configured such that it self-powers itself during sleep mode in the absence of energy from the energy harvester, and therefore it is not using any energy from the energy storage device 4. Once IC 3 is powered on, a control signal indicating the output voltage of the IC indicates that external energy has become available, and the IC is operable to extract that energy from the energy harvester 2.

[0050] exist Figure 2 In this configuration, IC 3 is connected to the solar cell, which has two main nodes or terminals: a positive terminal (+) called HRV+ and a negative terminal (-) called HRV-. These terminals represent the electrical contacts of the solar cell through which the generated current flows. Figure 2 As shown, inductor 10 (also referred to as a coil) is connected to the positive terminal of the solar cell. Inductor 10 is part of a voltage converter circuit, which in this case is a boost circuit configured to increase the voltage level of the input signal. This is also commonly known as a boost converter or voltage booster. Boost circuits are particularly useful where a higher voltage is required compared to the initially available voltage. Inductor 10 forms the core of the boost circuit so that when current flows through the inductor, it stores energy in its magnetic field.

[0051] It operates in two phases; in the first phase, energy from the input source is stored in the inductor's magnetic field, while in the second phase, the magnetic field decreases and gradually transfers its energy to the element connected to the output. In this latter phase, the voltage drop across the inductor is added to the input voltage, resulting in a higher output voltage.

[0052] The energy harvesting system 1 also includes: a second capacitor 11, also referred to as a first supplementary or additional energy storage element; and a third capacitor 12, also referred to as a second supplementary or additional energy storage element. In this example, the second capacitor is connected to the positive terminal of the solar cell (or more broadly, the energy harvester), while the third capacitor is connected to the output node 6 of the IC in this example. The second and third capacitors are used in this circuit to smooth out voltage fluctuations and thus prevent excessive voltage in the circuit.

[0053] In this example, the inverter circuit uses complementary metal-oxide-semiconductor (CMOS) technology. (As shown in...) Figure 2 As shown, a CMOS inverter is composed of both a p-type metal-oxide-semiconductor (PMOS) transistor 13 and an n-type metal-oxide-semiconductor (NMOS) transistor 14. The use of these two types of transistors allows for efficient signal conversion. The inverter circuit is configured to invert the state or logic level of a signal to its opposite state or logic level. Therefore, if a low (LOW) signal is fed into the inverter circuit, the inverter circuit flips it to a high (HIGH) signal. Conversely, if a high signal is fed into the inverter circuit, the inverter circuit flips it to a low signal.

[0054] As in this example, the watch is an electronic watch, and specifically a quartz watch. The watch system 8 includes a watch system IC 15 and a motor 16. An energy storage device 4 supplies power to the watch system IC 15, which includes a quartz crystal oscillator. The watch system IC uses the vibration of the quartz crystal to accurately measure time and then sends a signal to the motor 16 to drive the hands on the watch.

[0055] Figure 3The flowchart summarizes the operation of the energy harvesting system 1. In step 31, IC 3 detects that external energy has become available and exits sleep mode by energizing the first capacitor 9 and the energy from the energy harvester 2. In step 32, IC 3 begins to extract energy from the energy harvester 2. In step 33, IC generates a control or energy signal, which in this example is a high signal indicating that IC is operable and capable of extracting energy from the energy harvester. In step 34, the control signal is processed (inverted or not inverted) by an inverter circuit to control switch 5. More specifically, the inverter circuit inverts the control signal, which is then used to control the operation or electrical conduction of switch 5. Therefore, in step 35, as a result of the inverted control signal being applied to the gate terminal of the switch, the switch closes. In step 36, IC charges the accumulator with the energy extracted from the energy harvester 2 through the closed switch. In step 37, IC 3 determines whether external energy is still available. If yes, the process continues in step 36 by further charging the accumulator. If it is determined in step 37 that external energy is no longer available, then in step 38, IC 3 sets the control signal to a low value (low signal) indicating that it can no longer extract energy from energy harvester 2. In step 39, as a result of a high signal being applied to the gate terminal of switch 5, the switch opens. In step 40, IC is powered down and enters sleep mode until energy can be extracted from energy harvester 2 again. Note that in the process described above, the order of steps 32 and 33 can be reversed, or these steps can be performed simultaneously or substantially simultaneously.

[0056] Although the present invention has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or exemplary rather than restrictive, and the present invention is not limited to the disclosed embodiments. Other embodiments and variations will be understood and implemented by those skilled in the art based on a study of the drawings, this disclosure and the appended claims when the claimed invention is practiced.

[0057] In the claims, the word "comprising" does not exclude other elements or steps, and the quantifiers "a" or "an" do not exclude a plurality. The mere fact that different features are stated in mutually different dependent claims does not indicate that combinations of these features cannot be advantageously used. Any reference marks in the claims should not be construed as limiting the scope of this invention.

Claims

1. A circuit arrangement for extracting energy from an energy harvester, characterized by The circuit arrangement comprises: - an integrated circuit connected to the energy harvester and configured to extract energy from the energy harvester; - an energy accumulator configured to be connected to the integrated circuit for receiving the energy extracted by the integrated circuit; - a switch arranged between the integrated circuit and the energy accumulator to selectively disconnect the energy accumulator from the integrated circuit, wherein the integrated circuit is configured to output a control signal such that the control signal, either inverting or non-inverting, is configured to close the switch when the integrated circuit is able to extract energy from the energy harvester and to open the switch when the integrated circuit is not able to extract energy from the energy harvester, to thereby disconnect the integrated circuit from the energy accumulator.

2. The circuit arrangement of claim 1, characterized in that The circuit arrangement further comprises a load powered by the energy accumulator and connected to the energy accumulator such that the load is not connected to the energy accumulator through the integrated circuit.

3. The circuit arrangement of claim 1, characterized in that The load is directly connected to the accumulator.

4. The circuit arrangement of claim 2, characterized in that The load comprises a watch system.

5. The circuit arrangement of any one of claims 1 to 4, characterized in that The circuit arrangement further comprises a logic circuit arranged between the integrated circuit and the switch to process the control signal to be applied to the switch.

6. The circuit arrangement of claim 5, characterized by The logic circuit is an inverter circuit using a complementary metal-oxide semiconductor circuit.

7. The circuit arrangement of any one of claims 1 to 4, characterized in that The switch is a P-channel metal-oxide semiconductor field effect transistor.

8. The circuit arrangement of any one of claims 1 to 4, characterized in that The integrated circuit comprises a reserve energy storage element or is connected to a reserve energy storage element to help powering up the integrated circuit after it has been powered down to be able to extract energy from the energy harvester.

9. The circuit arrangement of claim 8, characterized in that The reserve energy storage element is a short-term storage capacitor.

10. The circuit arrangement of any one of claims 1 to 4, characterized in that When the switch is open, the integrated circuit is not able to be powered by the accumulator.

11. The circuit arrangement of any one of claims 1 to 4, characterized in that The circuit arrangement further comprises a boost circuit configured to increase the voltage level present at an output node of the energy harvester.

12. The circuit arrangement of any one of claims 1 to 4, characterized in that The control signal is characterized by a high signal value when the integrated circuit is able to extract energy from the energy harvester and by a low signal value when the integrated circuit is not able to extract energy from the energy harvester.

13. The circuit arrangement of any one of claims 1 to 4, characterized in that The energy harvester is at least one of: a solar cell, a kinetic or mechanical energy accumulator, a thermoelectric generator, a radio frequency harvester, and / or wherein the energy accumulator is a rechargeable battery and / or a supercapacitor.

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