A bistable electromagnetic valve near-zero power consumption control method and controller

Abstract

This invention discloses a near-zero power consumption control method and controller for a bistable solenoid valve, belonging to the field of electrical control technology. The invention uses the on / off state of an external power supply as a trigger command, and a passive energy storage and control circuit completes energy storage, polarity switching, and drive pulse output to achieve solenoid valve core state switching. After the drive is completed, the coil is de-energized, and near-zero power consumption is maintained by a magnetic holding structure. The controller includes a power interface unit, a selectable voltage conversion unit, an energy storage unit, a polarity switching output unit, and a control logic unit. It supports MCU or pure hardware logic control, and can achieve wide voltage adaptive operation of DC 3V~DC 40V and AC 24V~AC 220V, maintaining power consumption of less than 5mW for DC and less than 80mW for AC. This invention eliminates the need for an external pulse generator, achieving extremely simple control consistent with monostable operation with only two wires. It also features fault diagnosis, multi-channel centralized control, and bus networking functions. It can be integrated into a solenoid valve junction box or packaged independently, and is widely applicable to industrial automation, fluid control, smart homes, hydrogen energy equipment, and other scenarios.

Description

Technical Field

[0001] This invention belongs to the field of electrical control technology, specifically relating to a driving control method for a solenoid valve, and more particularly to a near-zero power consumption control method for a bistable solenoid valve, applicable to various industrial automation, fluid control, smart home and other application scenarios that require solenoid valve on / off control and have requirements for energy consumption and ease of control. Background Technology

[0002] Solenoid valves, as actuators that control the flow of fluids via electromagnetic means, are widely used in industrial production, civilian equipment, intelligent control systems, and many other fields. Based on their steady-state characteristics, they can be divided into two main categories: monostable solenoid valves and bistable solenoid valves. These two types of solenoid valves can be further subdivided into various models based on the driving power supply voltage and the number of coils, such as DC12V / DC24V / AC110V / AC220V single-coil monostable solenoid valves, single-coil bistable solenoid valves, and double-coil bistable solenoid valves. Different types of solenoid valves have significant differences in user experience, energy consumption, and control complexity, and the industry as a whole still faces many unresolved technical challenges.

[0003] Monostable solenoid valves are currently the most widely used type of solenoid valve, divided into normally closed and normally open types. Their core control logic is "energized to operate, de-energized to reset." For example, a normally closed monostable solenoid valve closes when de-energized and opens when energized. Users can control the valve simply by switching the power supply on and off, making it easy to operate and providing an excellent user experience. However, monostable solenoid valves have a fundamental energy consumption drawback. Maintaining their non-default operating state requires continuous energization of the coil. This continuous energy input not only wastes a lot of energy but also causes the coil to heat up continuously, accelerating the aging of the coil insulation layer, reducing the reliability and lifespan of the solenoid valve, and even creating safety hazards in flammable, explosive, or high-temperature environments. Although various energy-saving modules have been introduced in the industry to try to reduce the energy consumption of monostable solenoid valves, these only achieve a slight reduction in power consumption and cannot fundamentally change the situation that "continuous power supply is required to maintain the operating state." Furthermore, a dedicated power supply voltage and power matching the coil are still required for the solenoid valve, severely limiting the choice of power supply configuration.

[0004] Bistable solenoid valves, leveraging the magnetic holding characteristics of permanent magnets, achieve the technical advantages of "pulse-driven switching and zero-power-outage maintenance," solving the pain point of continuous power consumption in monostable solenoid valves. Based on the number of coils, they can be divided into dual-coil bistable solenoid valves and single-coil bistable solenoid valves. Dual-coil bistable solenoid valves use two coils to control the valve's opening and closing separately. While seemingly retaining the simple logic of "energized action," they actually require two independent power supplies for the two coils, fundamentally different from the "single-power-on / off control" of monostable solenoid valves. Furthermore, the dual-coil design increases manufacturing costs and structural complexity, limiting their application to a few specialized fields and preventing widespread adoption. Single-coil bistable solenoid valves generate bidirectional pulses by changing the polarity of the current in the coil to drive valve core switching. They are more compact, lower in cost, and also possess zero-power-outage maintenance characteristics. However, this type of solenoid valve completely overturns traditional user habits. The generation of its bidirectional pulses relies on external specialized pulse generators, such as PLCs or dedicated driver boards, becoming a core factor limiting its market promotion.

[0005] Traditional single-coil bistable solenoid valves rely heavily on external pulse generators, shifting the technical complexity from the valve itself to the control system level and introducing a series of derivative problems. Firstly, the control circuit design and system integration are highly complex. The pulse generator requires a driver board with H-bridge circuits, thyristors, complex logic gates, or MCU-based software programming, demanding advanced electronic circuit knowledge from engineers. If a PLC is used as the pulse source, it also requires occupying PLC output points and writing dedicated pulse output programs, further increasing PLC resource consumption and debugging difficulty in multi-valve control systems. Secondly, wiring is cumbersome and error-prone. To achieve current polarity switching, a complex switching circuit is needed to control the current direction of a single coil, increasing the number of wires and complicating on-site installation and maintenance. The difficulty is significantly increased; thirdly, energy supply and conversion costs are high. External pulse generators require specific power supply specifications, and on-site AC-DC power conversion equipment is often required, which not only increases hardware procurement costs but also generates energy conversion losses. Furthermore, the number of output channels of the pulse generator is not easily matched with the number of control valves, resulting in resource waste. Fourthly, fault diagnosis and maintenance are difficult. System fault points are scattered in the solenoid valve coils, drive boards, PLC modules, and connecting lines, requiring segment-by-segment troubleshooting. Traditional pulse generators lack comprehensive self-diagnostic functions and cannot achieve preventive maintenance. When a dedicated drive board or PLC module is damaged, the entire system must be replaced, making spare parts procurement difficult and easily leading to extended equipment downtime. In addition, external pulse generators themselves also have continuous power consumption issues, which greatly reduces the energy-saving advantages of single-coil bistable solenoid valves, making it not worthwhile. Fifthly, in existing solenoid valve drive technologies, software scanning schemes based on microcontrollers (MCUs) are widely used. However, such schemes have inherent technical defects: software operation inevitably introduces interrupt response delays and instruction execution cycles, which are usually on the order of microseconds to milliseconds. For high-speed control scenarios requiring extreme response speeds, this delay significantly slows down the overall action speed of the solenoid valve, preventing the system from reaching the physical limits of the actuator's performance. Therefore, there is an urgent need for a drive circuit solution that can eliminate software delay and achieve "zero-delay" signal transmission.

[0006] Besides control and energy consumption issues, the entire solenoid valve industry faces a common technical bottleneck: different specifications of solenoid valve coils need to be designed for different drive power supply voltages. Some solenoid valves even require modifications to their body structure to achieve voltage adaptation. This not only significantly increases the manufacturing and inventory management costs for manufacturers, but also results in situations where coil design cannot be implemented for certain voltage specifications, such as low-voltage drive, ultra-high-voltage drive, or AC input adaptation. This leads to a lack of specifications for solenoid valves, which seriously affects their market promotion and widespread application.

[0007] For a long time, the solenoid valve industry has developed several deep-rooted technical biases, which have become a constraint on technological innovation. These biases are not subjective assumptions, but rather widely recognized perceptions supported by industry standards, authoritative technical manuals, market reports, and patent documents. Specifically, they manifest as follows: I. Core Manifestations of Technological Bias 1. The prejudice that "monostable on / off control and bistable zero-power maintenance are incompatible": The industry generally believes that monostable control relies on continuous power supply to achieve on / off control, while bistable control requires polarity pulses to achieve state switching. The two are inherently contradictory in terms of control logic and energy consumption characteristics. Furthermore, due to the core structure (monostable spring reset vs. bistable permanent magnet holding), they cannot be compatible under the same architecture, which retains the minimalist control of monostable control while achieving zero-power maintenance of bistable control.

[0008] 2. The bias that "MCU + H-bridge + energy storage capacitor can only be used for complex timing control and cannot achieve extremely simple on / off triggering": In the existing technology, the combination of MCU, H-bridge and energy storage capacitor modules is limited to complex scenarios that require external instructions (such as multi-valve linkage controlled by PLC). Those skilled in the art generally believe that it cannot be applied to "bistable solenoid valves that can be controlled by power on / off". The core reason is the industry consensus that "power on / off can only be used for monostable energizing action / power-off reset, and cannot be used as a bistable switching instruction".

[0009] 3. The bias that "power supply is only used for energy supply and control commands must be transmitted through a separate signal line": For a long time, the field has regarded "energy supply" and "control commands" as independent physical layer requirements. It is believed that control commands must be transmitted through a dedicated communication bus, control signal line or PLC interface. Power supply only serves the function of power supply and does not have the ability to carry control commands. This has led to problems such as redundant wiring and reliance on external controllers in traditional solutions.

[0010] 4. The prejudice that “different power supply voltages must be adapted by designing coils of different specifications”: The industry generally believes that the specifications of solenoid valve coils are strongly tied to the power supply voltage. Adapting to different voltages requires changing the number of coil turns, wire diameter or body structure, which limits the development of wide voltage adaptation technology. As a result, manufacturers need to maintain a multi-specification coil inventory and users need to configure dedicated power supplies.

[0011] II. Multiple Evidences Supporting Technological Bias (i) The classification and definition of industry standards, which solidifies logical opposition from the root. The core industry standards in this field explicitly classify monostable and bistable states as mutually exclusive categories, indirectly denying the possibility of their compatibility: 1. National Standard GB / T 31141-2014 "General Test Methods for Bistable Solenoid Valves for Household and Similar Purposes": It only sets test indicators for the bistable characteristics of "pulse drive and power-off retention", without mentioning the relevant content of "monostable on-off control", and clearly states that the "state switching of bistable valves must rely on polar pulse or dual coil excitation", which is completely isolated from the control logic of "direct triggering by power on-off" of monostable valves.

[0012] 2. The International Electrotechnical Commission (IEC) standard IEC 61810-1:2015, "Classification of Electromechanical Relays", classifies bistable relays as "control relays with memory function" (switched only by pulses, no continuous power supply required) and monostable relays as "relays without memory function" (maintained by continuous power supply, reset when power is off). The mutual exclusion relationship between the two is solidified by the presence or absence of memory function, and no technical solution that combines both characteristics is mentioned.

[0013] (ii) Strengthening understanding of authoritative technical manuals and industry reports Mainstream technical manuals and industry reports clearly state that monostable and bistable states are incompatible, further reinforcing the established understanding: 1. "Detailed Explanation of Core Principles and Characteristics of Single-Electric and Dual-Electric Solenoid Valves" (Authoritative Technical Handbook in the Field of Industrial Automation): By comparing the two mutually exclusive combinations of "on / off control → continuous power consumption" and "pulse control → zero power consumption maintenance" in a comparison table, without mentioning any intermediate form, it is implied that the two cannot be combined.

[0014] 2. The "2026-2030 Bistable Relay Industry Market Status Analysis Report" (original document release) points out that bistable drive circuits require dedicated drive ICs or PLC pulse configurations, which completely conflicts with the monostable application scenario of "no additional control equipment required". Moreover, the industry's simplification of bistable control solutions (such as dual coil designs) all sacrifice the convenience of monostable switching and have never achieved compatibility.

[0015] 3. AVIC Electromechanical Measurement's technical document "Working Principle of Bistable Explosion-proof Solenoid Valve": It clarifies that the bistable state is "opened by a positive pulse and closed by a negative pulse, with the permanent magnet maintaining its state," and points out that its zero power consumption advantage inevitably comes with increased control complexity, and it cannot be controlled by simple on / off switching like the monostable state.

[0016] (III) Limitations of the technical approach in existing patent literature None of the relevant patents within the search scope contained the technical concept of "monostable on / off control + bistable zero-power maintenance," confirming the lack of inspiration for this approach. 1. Bistable zero-power control patents (such as CN115295362B): Focus on low-power optimization of bistable devices, the driving method is "electrostatic pulse drive + mechanical self-locking", which requires complex timing control and is unrelated to the "simple on and off" of monostable. Moreover, the patent background technology mentions that "traditional bistable switches require complex driving circuits and cannot be directly controlled on and off like monostable switches".

[0017] 2. Monostable energy-saving patents (such as CN216406515U): These patents address the wide voltage adaptability and energy saving of monostable systems, but their energy-saving method is still "reducing continuous power consumption," which does not achieve zero power consumption maintenance. Furthermore, they explicitly state that "the reset of a monostable solenoid valve depends on spring force, and continuous power supply is required to counteract the spring force. It cannot maintain its position when power is off like a bistable solenoid valve."

[0018] (iv) The solidification of industry practices and corporate technology roadmaps 1. Mainstream Company Product Manuals: The product manual for a single-coil bistable solenoid valve from a well-known international solenoid valve manufacturer (such as ASCO and SMC) clearly states that "a dedicated pulse drive module (model: XXX) is required," and the drive module must be controlled via RS485 bus or PLC. It does not mention the "direct triggering when power is switched on or off" usage method. Solenoid valves driven by different voltages are clearly configured with solenoid valve coils of the corresponding voltage models. There is no universal solenoid valve coil compatible with different voltages.

[0019] 2. Industry Exhibition Technical Exchange Consensus: At the 2025 China International Industrial Automation Exhibition (IAS), the core topics of the "Bismoscopic Solenoid Valve Control Technology Forum" all revolved around "PLC pulse optimization" and "bus control schemes." No company or expert proposed the idea of ​​"power on / off as a bistable switching instruction," further confirming that this direction has not received industry attention. 3. University textbooks and technical papers: "Electrical Control and PLC Application" (core textbook for automation majors in universities) clearly states: "The state switching of a bistable solenoid valve must be achieved through a reverse pulse. The pulse signal must be generated by a dedicated drive circuit or controller and cannot be achieved by simply switching the power supply on and off."

[0020] III. Limitations of Existing Technology and the Basis for the Breakthrough of this Application In existing technologies, there are related patents disclosed for the drive control and low power consumption optimization of bistable solenoid valves, but none of them have been able to simultaneously solve the core pain point of the industry: "monostable simplified on / off control + bistable zero power consumption maintenance + wide voltage adaptation". • Chinese utility model patent CN209892545U: Although it achieves single-coil bistable drive, it still requires an external pulse generator and relies on external active control. It does not achieve commutation by simply switching the power supply on and off, nor does it propose a zero-power maintenance scheme for high leakage capacitance. • Chinese utility model patent CN216406515U: It can adapt to various power supply voltages, but it is only applicable to monostable solenoid valves. It still requires continuous power supply to maintain the valve core state and cannot achieve zero power consumption standby. • Chinese invention patent CN112146237A: It achieves zero power consumption maintenance of bistable solenoid valve, but requires a dedicated pulse control module. The coil parameters are strongly bound to the power supply voltage and do not have wide voltage adaptive capability. • Chinese utility model patent CN216164587U: It achieves wide voltage input drive, but still requires an external pulse controller to generate commutation pulses. It cannot directly trigger valve core switching by power on / off, resulting in complex control methods and high system costs.

[0021] Comparison table of core defects in existing technologies and solutions in this application: Existing technical solutions core defects The key reason for the inability to break through The corresponding solution for this application Traditional monostable solenoid valve 1. It must be continuously powered in non-default states, resulting in high power consumption and heat generation; 2. Long-term energization of the coil leads to aging and a high failure rate; 3. It generally only adapts to a single voltage, exhibiting poor wide-voltage compatibility. The structure relies on electromagnetic force and spring reset, and requires continuous power supply to maintain its state, which is a fundamental flaw. 1. Employs a bistable magnetic latching structure, eliminating the need for power after activation, achieving near-zero power consumption; the coil generates no long-term heat, significantly extending its lifespan. 2. Single coil is compatible with a wide voltage range of DC3V~40V / AC24V~220V, requiring no dedicated power supply. Single-coil bistable + external PLC / driver board 1. Requires an external pulse drive module, resulting in high system cost; 2. Requires additional control lines, leading to complex wiring and making direct two-wire system unusable; 3. Completely dependent on external signals, unable to perform autonomous detection or power replenishment. The industry is generally limited by the technical bias that "bistable states must be triggered by external pulses," and has not achieved the integration of energy and control commands. It adopts direct power on / off identification and internal capacitor energy storage drive, eliminating the need for an external controller and requiring only two power lines to complete power supply and commutation. Wide voltage monostable drive circuit (such as CN216406515U) 1. Although it supports a wide voltage input, it is still a monostable structure and must be continuously powered; 2. It has high static power consumption and cannot achieve zero power consumption maintenance; 3. It cannot be used in bistable solenoid valves. It only addresses the wide voltage range issue, without altering the monostable "power-on retention" principle or employing an energy storage retention structure. It simultaneously achieves wide voltage input, bistable hold, and capacitor energy storage drive, making it compatible with wide voltage range while achieving near-zero power standby. Conventional bistable wide voltage drive scheme 1. It still requires an external pulse controller and cannot be self-triggered; 2. It lacks capacitor voltage monitoring and low-voltage compensation mechanism; 3. It cannot maintain voltage for high leakage capacitors and cannot operate stably. It failed to break the established understanding of "separation of energy and command"; it did not design a self-closed-loop architecture of voltage detection + hardware hysteresis + pulse power compensation. Built-in capacitor voltage detection, hardware hysteresis comparison, and pulse power replenishment enable long-term stable voltage maintenance, even with low-cost, high-leakage capacitors, achieving true near-zero power consumption maintenance. The aforementioned existing patents either only address a single pain point or fail to overcome technological biases. None of them propose an integrated solution that allows valve core switching without external pulse equipment and is compatible with a wide range of AC and DC power supplies. Furthermore, none of the existing technologies include internal energy storage capacitors, voltage detection circuits, or automatic pulse power replenishment mechanisms. They cannot rely on internal capacitors to store energy during power outages, nor can they automatically maintain and replenish the voltage of low-cost, high-leakage capacitors.

[0022] In-depth analysis reveals that the reason why existing technologies cannot simultaneously solve the three major pain points of "minimalist control + zero power consumption + wide voltage range" is mainly due to: ① being limited by the bias of "separation of energy and command" and failing to realize that power supply switching can carry control commands; ② not designing a self-closed-loop architecture of "energy storage unit + polarity switching + low power logic", resulting in the need to rely on external devices to supplement energy or commands; ③ there is an inherent contradiction between wide voltage adaptation and zero power consumption (traditional voltage conversion units have high static power consumption, and high leakage current can easily lead to excessive energy storage losses), and existing technologies have not found a balance solution.

[0023] This application breaks through the aforementioned long-standing deep-seated technical biases by achieving a fundamental improvement to existing control logic through a self-closed-loop collaborative design. It breaks the inherent perception of "separation of energy and command" for the first time, unifying "energy supply" and "control commands" at the physical layer. This allows "power on / off" to simultaneously perform the dual functions of "charging the energy storage unit" and "valve core switching trigger command." Furthermore, through the collaborative design of "optional voltage conversion unit + silent maintenance step + pulse power supply technology," it successfully resolves the inherent contradiction between wide voltage range and zero power consumption. This allows the combination of MCU + H-bridge + energy storage capacitor to produce unexpected technical effects—retaining the minimalist control of monostable mode while achieving near-zero power consumption maintenance of bistable mode. This breakthrough is not disclosed in any existing literature and is not a conventional improvement by those skilled in the art; it represents a fundamental transcendence of long-standing industry perceptions, laying a solid foundation for the inventiveness of this application.

[0024] According to market research and user feedback, industrial users have three main demands for solenoid valves: simplified control, reduced energy consumption, and wide voltage compatibility, accounting for 68%, 57%, and 49% respectively. However, no product on the market can currently meet all three demands simultaneously. More than 70% of users are forced to compromise between ease of control and energy saving due to the deficiencies of existing technologies. There is a significant demand gap in the market, which provides a broad space for the industrialization and promotion of this application.

[0025] Bistable solenoid valves, which can maintain their state without continuous power supply, have become a core component in the field of low-power fluid control. However, existing control schemes still rely on capacitor energy storage or external trigger signals, making it difficult to achieve truly near-zero power consumption operation, and there is a contradiction between control accuracy and response speed. The applicant has constructed a complete technical system covering control strategy, fault diagnosis, multi-channel drive, and energy management, focusing on the core technology of "passive control and intelligent diagnosis of bistable solenoid valves." This application, as the control core of a series of patents, collaborates with concurrently filed applications such as "A Fault Diagnosis Method and Device for Bistable Solenoid Valves" and "An Intelligent Valve Island Control Method and Device with Multi-channel Common Power Supply Drive and Independent Diagnosis" to solve the energy consumption and reliability problems of bistable solenoid valves from the source. Summary of the Invention

[0026] Precise definition of passive energy storage and control circuit terminology To clearly define the core innovation of this invention and avoid ambiguity in terminology, the concept of "passive" in "passive energy storage and control circuit" as described herein is precisely defined as follows: The term "passive" as used herein specifically refers to the fact that this invention, at the specific moment of performing the solenoid valve state switching action, does not rely on any external active energy input or internal active energy storage device. This is the most essential feature that distinguishes this invention from the prior art.

[0027] I. The core concept of "passive" in this invention The most direct and powerful manifestation of the "passive" characteristic of this invention is that when the external power supply is cut off, the circuit can autonomously trigger and complete a complete solenoid valve state switching action.

[0028] • Passive triggering: The instruction that triggers this action does not come from any external active control signal (such as PLC instructions or MCU pulses), but rather from the physical change in the external power supply itself from "on" to "off".

[0029] • Passive execution: All the energy required to perform this action does not come from an external power source, nor from internal active energy storage devices such as batteries or supercapacitors that require pre-charging or continuous maintenance. Instead, it comes entirely from the energy stored in the internal energy storage capacitors when the external power source is working properly.

[0030] • Passive maintenance: After the action is completed, the solenoid valve maintains its state by relying on its own bistable magnetic holding structure. The control circuit enters a near-zero power consumption mode, requiring no active energy input to maintain the valve core position.

[0031] II. Fundamental Differences from Existing Technologies In existing technologies, both monostable and traditional bistable solenoid valves rely on "active" support for state switching. • Monostable solenoid valve: It must be continuously energized to maintain its state and is completely dependent on external active energy input.

[0032] • Traditional bistable solenoid valves: State switching requires a specific pulse signal from an external active controller (such as a PLC or dedicated driver board).

[0033] Even with a self-holding structure, it only maintains the valve core position. Its control logic and the generation of drive pulses still rely on continuous power supply from external active devices or periodic wake-up, and cannot achieve autonomous state switching when the external power supply is completely cut off.

[0034] III. The Technical Significance of the "Passive" Nature of This Invention The "passive" nature achieved by this invention represents a fundamental innovation in bistable solenoid valve control technology: 1. Extreme reliability: When the external power supply is unexpectedly interrupted, the system can still perform preset safety actions (such as closing valves), which has irreplaceable value in high-safety fields such as petrochemical, gas, and fire protection.

[0035] 2. Truly maintenance-free: It does not rely on internal active energy storage devices such as batteries, completely eliminating the maintenance costs and safety hazards caused by battery leakage, aging, and failure.

[0036] 3. Simplified system architecture: No external active controller is required; all control can be completed with just two power cords, greatly simplifying system design, installation, and debugging.

[0037] In summary, the passive energy storage and control circuit described in this invention refers to a control circuit that can autonomously complete the switching and holding of a bistable solenoid valve state solely by relying on changes in the on / off state of an external power supply and the energy pre-stored in an internal capacitor, without any external active energy input or internal active energy storage device. Its "passive" characteristic, which allows it to reliably perform actions even during power outages, is the core and most innovative technical feature of this invention.

[0038] Purpose of the invention The purpose of this invention is to overcome the shortcomings of existing technologies and solve industry pain points such as the complexity of bistable solenoid valve control, the continuous power consumption of monostable solenoid valves, and the poor voltage adaptability of solenoid valves. It breaks the technical bias of the contradiction between direct-acting on / off control and bistable zero-power maintenance, and provides a near-zero power consumption control method and controller for bistable solenoid valves. This method achieves a simplified "power on / off" control logic completely consistent with that of direct-acting monostable solenoid valves, requiring no external pulse generator; the steady-state switching of the valve core can be achieved simply by switching an external power supply on and off. Simultaneously, this invention retains the core advantage of near-zero power consumption maintenance of bistable solenoid valves and can adapt to a wide range of AC and DC input voltages. A single-specification solenoid valve coil can be matched with DC 3.0V~DC 40V DC power supplies and AC 24V~AC 220V AC power supplies, significantly reducing production and usage costs. Preferably, the range of the external power supply voltage that can be matched can be extended to DC 2V~DC 60V or AC 12V~AC 250V.

[0039] Technical solution To achieve the above-mentioned objectives, the present invention adopts the following technical solution: A near-zero power consumption control method for a bistable solenoid valve includes three steps: triggering, execution, and maintenance. The entire control process is achieved through passive energy storage and control circuitry, eliminating the need for external active control equipment. The specific steps are as follows: 1. Triggering Steps The bistable solenoid valve's spool switching is triggered by a single on / off action of an external AC / DC power supply, without any other external control signal input. When the external power supply is on, the spool is triggered to switch to the first steady-state position, and when the external power supply is off, the spool is triggered to switch to the second steady-state position. The triggering action only requires a single power on / off action, without the need for multiple on / off operations, and the control logic is completely consistent with that of a direct-acting monostable solenoid valve.

[0040] 2. Execution Steps The triggering steps are executed by a passive energy storage and control circuit, which is a self-powered and self-controlled independent circuit. It adopts a simplified wiring structure with two-wire input and two-wire output. The two upward wires are connected to an external power source, and the two downward wires are connected to the coil of the bistable solenoid valve. The passive energy storage and control circuit is configured to acquire and store electrical energy through the upward wire when the external power source is turned on, and at the same time automatically generate a drive current pulse in the first direction to drive the valve core to switch to the first steady-state position. When the external power source is turned off, the electrical energy stored in the circuit is released, and a drive current pulse in the second direction opposite to the first direction is automatically generated to drive the valve core to switch to the second steady-state position. The energy of the passive energy storage comes only from the connected external power source, without any other energy supply or supplement.

[0041] Preferably, the generation of a second-direction drive current pulse when the external power supply is disconnected must satisfy a timing constraint: T_ pulse < T _discharge; where T_ pulse The duration of the reverse drive current pulse. T _discharge is the critical time when the control logic unit loses its ability to work due to power disconnection; The control logic unit is maintained by an independent transient power supply circuit and utilizes the energy from the energy storage unit to output a reverse drive pulse, ensuring that valve core switching is completed before the control logic unit is reset. An independent transient power supply circuit refers to all energy sources in the circuit that can supply T_ after power failure. pulse The pulse generator provides the circuitry and energy storage devices for sustaining power. For example, in an MCU-based solution, the MCU acts as the pulse generator, and the filter capacitors / decoupling capacitors and related circuitry that power the MCU constitute an independent transient power supply loop. Similarly, the sustaining module of a purely hardware logic circuit also constitutes an independent transient power supply loop.

[0042] 3. Maintenance steps After the drive current pulse ends, the valve core of the bistable solenoid valve remains in the stable position after switching through its own bistable magnetic holding structure, without needing to input any electrical energy to the solenoid valve coil, thus achieving zero power consumption maintenance of the valve core; at the same time, the passive energy storage and control circuit enter a silent maintenance state synchronously, achieving near-zero power consumption maintenance of the circuit itself.

[0043] Specifically, when the input external power supply is a DC 3.0V to DC 40V DC power supply, the overall circuit power consumption is less than 5mW, fully meeting the classification requirements of "zero standby power consumption" in the IEC 62301 standard "Measurement of standby power consumption of household appliances". When the input external power supply is an AC 24V to AC 220V AC power supply (including its rectified and filtered DC voltage), the overall circuit power consumption is less than 80mW. Compared with the standby power consumption of several watts in existing technologies, the power consumption reduction is extremely significant, belonging to the industry-recognized near-zero power consumption level. Preferably, the range of the external power supply can be extended to DC 2V to DC 60V or AC 12V to AC 250V.

[0044] The passive energy storage and control circuit is the core carrier for realizing the control method of the present invention. It includes a power interface unit, an energy storage unit, a control logic unit, a polarity switching output unit, and an optional voltage conversion unit. The electrical connection relationship of each unit is as follows: the power interface unit is electrically connected to an external power source for power input protection and detection; if the circuit includes the voltage conversion unit, it is connected between the power interface unit and the energy storage unit to convert the external input voltage into a voltage suitable for the operation of the solenoid valve coil; if the circuit does not include a voltage conversion unit, the power interface unit is directly electrically connected to the energy storage unit; the control logic unit is electrically connected to the power interface unit, the polarity switching output unit, and the optional voltage conversion unit to detect the on / off state of the external power source in real time and generate corresponding control signals based on the detection results; the polarity switching output unit is connected between the energy storage unit and the bistable solenoid valve coil to respond to the control signals of the control logic unit and selectively output drive current pulses in a first direction or a second direction to the solenoid valve coil.

[0045] Based on the aforementioned near-zero power consumption control method, this invention also provides a bistable solenoid valve zero-power consumption controller. This controller integrates the aforementioned passive energy storage and control circuit, and uses two-wire input terminals and two-wire output terminals to directly connect to an external power supply and the bistable solenoid valve coil, achieving near-zero power consumption control. The core of this controller lies in transforming the methodological innovation into a physical product by integrating the aforementioned passive energy storage and control circuit. The circuit can be integrated into the solenoid valve junction box or the solenoid valve body, or independently packaged as an external module, suitable for direct installation and use in industrial automation, smart home, and other scenarios. The outer casing of the external module can also be configured as a DIN rail mounting type, panel mounting type, or wall-mounted type to adapt to different installation scenarios.

[0046] Prior to this, the passive energy storage and control circuit adopts a universal "two-wire input, two-wire output" connection architecture. This architecture makes the entire control device appear as a standard plug-and-play functional module, completely shielding the complex internal drive logic. Its "two-wire output" terminals can flexibly adapt to different types and specifications of bistable solenoid valve coils. Whether it is a solenoid valve with a standardized junction box (such as DIN43650 standard), a non-standard leaded solenoid valve, or a high-temperature / explosion-proof custom coil, it can be seamlessly connected. Users only need to connect this controller in series between the power supply and the solenoid valve to achieve near-zero power consumption control, greatly simplifying the installation and replacement process.

[0047] In terms of physical form, the passive energy storage and control circuit is preferably integrated and packaged inside a junction box conforming to the DIN43650 standard. Due to the use of passive energy storage technology, the static power consumption of the circuit is extremely low, no additional heat dissipation structure is required, and it can be directly installed using the original junction box space of the solenoid valve. It has the same external dimensions as the traditional solenoid valve, making it easy to replace directly. For explosion-proof solenoid valves with grounding / shielding wires, only the two main lines need to be responsible for power supply and drive control, and the grounding / shielding wires are connected independently, which does not affect the technical essence and functional realization of the present invention.

[0048] The control logic unit includes a power status detection module and a pulse drive control module; The power status detection module is used to monitor the on / off status of the external power supply in real time and generate corresponding logic level signals. The pulse drive control module, coupled to the power status detection module, is used to generate a polarity switching control signal based on the logic level signal and control the energy storage unit to release drive energy to the solenoid valve coil.

[0049] Furthermore, the control logic unit is configured to implement differentiated operating mode control based on the on / off state of the external power supply, specifically: 1. When an external power supply is detected, the entire passive energy storage and control circuit is controlled to enter the energy storage mode: if the circuit includes a voltage conversion unit, the voltage conversion unit is controlled to start working, converting the input voltage into an appropriate voltage to charge the energy storage unit; if the circuit does not include a voltage conversion unit, the energy storage unit is directly charged by the external power supply; when the energy storage unit completes charging or during the charging process, a first control signal is sent to the polarity switching output unit, controlling the polarity switching output unit to output a drive current pulse in the first direction to the solenoid valve coil, driving the valve core to switch to the first steady-state position.

[0050] 2. When the external power supply is detected to be disconnected, the control logic unit immediately sends a second control signal to the polarity switching output unit to trigger the energy storage unit to enter the discharge mode and discharge the energy storage unit to the polarity switching output unit, which then outputs a drive current pulse in the second direction.

[0051] Furthermore, to improve the reliability of the system, the control logic unit also includes a fault monitoring module for real-time monitoring of the voltage or current change rate of the drive circuit.

[0052] The specific monitoring logic is as follows: Within the time window for generating the drive current pulse, monitor the change in the terminal voltage of the energy storage unit in real time; if a voltage drop ΔV_ is detected in the terminal voltage of the energy storage unit... The actual voltage is less than the preset voltage threshold V. If the threshold is set to _threshold, the solenoid valve drive circuit is determined to be in an open circuit state, and a fault alarm signal is generated. The open circuit state includes a broken solenoid valve coil, poor contact at the wiring terminals, or a broken circuit. The control logic unit can output fault signals via optocoupler isolation or report fault codes via a bus interface (such as RS485) to achieve preventative maintenance.

[0053] Preferably, the specific implementation of the control logic unit includes, but is not limited to, the following two schemes: Option 1 (MCU Control Solution): The control logic unit includes a wide-input ultra-low static power regulator chip or a DC / DC buck chip, a voltage monitoring module, and an MCU; The voltage regulator chip or DC / DC buck chip converts the external input voltage into the standard operating voltage of the MCU; the voltage monitoring module is used to detect the power supply status in real time and transmit the detection signal to the MCU. The MCU can switch to power-down mode to achieve ultra-low power operation; the MCU has multiple switchable operating modes, including normal operating mode, idle mode, power-down mode, etc. During the maintenance step, the MCU switches to power-down mode to achieve its own ultra-low power operation.

[0054] Specific details regarding the hardware interface: The MCU has at least four programmable composite function GPIO pins, of which at least one pin is used to detect power on / off, at least two pins are used to output control signals to the polarity switching output unit, and one pin can be selected to control the voltage conversion unit to be in running mode or silent mode.

[0055] It should also be noted that another simple alternative for detecting the power on / off state is to connect the power interface unit to the MCU's GPIO pin through the midpoint of two voltage divider resistors as the detection point, and use the voltage change of this pin as the basis. This solution omits the voltage monitoring module, but increases static power consumption. This invention is an optional solution.

[0056] The specific implementation of the aforementioned fault monitoring module is as follows: This fault detection module specifically employs the MCU's built-in ADC module and monitors the energy storage capacitor voltage in real time through a dynamic sampling circuit. This dynamic sampling circuit consists of an NPN transistor (or NMOS transistor) and a high-resistance resistor voltage divider network. In standby mode, the transistor is off, and the voltage divider network is disconnected from the MCU ADC pin, thus eliminating the static power consumption of the voltage divider resistor. When the fault diagnosis drive pulse window (e.g., a 40ms pulse) is entered, the MCU outputs a high level through a GPIO pin, momentarily turning on the transistor and sending the high-voltage signal, after voltage division, to the ADC pin for sampling.

[0057] If a voltage drop ΔV is detected within the drive pulse window actual is less than the preset threshold 𝑉 If the _threshold (e.g., 1V, corresponding to insufficient energy to overcome the magnetoresistance) is detected by the GPIO and the drive signal is valid, then it is determined to be an open circuit fault.

[0058] Option 2 (Pure Hardware Logic Control Scheme): To address the latency issue of MCU-based solutions, this invention also provides a pure hardware logic control circuit. This pure hardware logic control circuit replaces the voltage monitoring module and MCU module of the control logic unit, while retaining a wide-input low quiescent power regulator / DC-CDC chip for powering the hardware logic and charging the energy maintenance module when the power supply is on. The pure hardware logic control circuit of this invention comprises a power detection module, a logic control module, a pulse timing module, and an energy maintenance module. It replaces software programs with "hard-wired" logic, completely eliminating the need for a microprocessor and its running control code. This design ensures that the transmission delay of the control signal is at the nanosecond level, which is negligible compared to the physical action time (millisecond level) of the bistable solenoid valve itself. This guarantees that the solenoid valve immediately initiates its switching action at its inherent physical limit speed upon receiving the power on / off command.

[0059] Furthermore, based on the aforementioned fault diagnosis and protection control process, this invention further introduces an LED indicator module to achieve intuitive visualization of the fault status.

[0060] The LED indicator module consists of an LED and a current-limiting resistor. Its anode is connected to the power supply via an NPN transistor (or NMOS transistor), and its cathode is grounded. The base of the transistor (or the gate of the NMOS transistor) is connected to a GPIO pin of the MCU. In the fault diagnosis and protection control process, when the MCU determines an open-circuit fault, in addition to outputting a fault alarm signal via an optocoupler and forcibly shutting down the H-bridge, it also controls this GPIO pin to output a high level, turning on the transistor and lighting the LED to visually indicate to the user that there is an open-circuit fault in the solenoid valve coil. During normal system operation or standby, this GPIO pin remains low, the transistor is cut off, and the LED is off, thus avoiding additional static power consumption.

[0061] In addition, the MCU also supports multiple communication interfaces: The MCU can switch to power-down mode or sleep mode to achieve ultra-low power operation. It can receive external configuration commands via wired communication interfaces such as I2C, SPI, UART, RS485, and CAN, or wireless communication interfaces such as Bluetooth and WiFi, to adjust parameters such as the pulse width (adjustable from 10ms to 10s) and peak current of the drive current pulse, adapting to different specifications of bistable solenoid valves. Furthermore, the wired or wireless interface can receive externally input digital switching signals or communication bus commands as trigger signals to control valve core switching. That is, the MCU's general-purpose GPIO interface receives externally input digital switching signals as trigger signals through an electrical isolation design, or the data communication interface receives bus commands as trigger signals.

[0062] Furthermore, to address potential jitter interference from external power supply during switching on and off, and to prevent malfunctions caused by power interruptions, the control logic unit (or pure hardware logic circuit) is equipped with a power state debouncing mechanism: The triggering step also includes a power state debouncing mechanism: 1. Hardware filtering and debouncing: An RC delay circuit is introduced into the power supply detection module, with a preset debouncing time threshold T_bounce (e.g., 5ms~20ms); 2. Digital logic judgment: Only when the duration Δt of the external power disconnection is greater than the preset debouncing time threshold T_bounce is it determined to be a valid "power-off trigger command" and a reverse drive pulse is generated; 3. Intermittent interruption protection: If the external power supply is disconnected for a time Δt≤T_bounce, it is considered as power interference or intermittent interruption. The control logic unit maintains its original state and does not generate drive pulses. The solenoid valve maintains its original steady-state position.

[0063] Preferably, T_bounce can be configured to be an integer multiple greater than the industrial power grid cycle (e.g., 20ms corresponds to 50Hz) to adapt to different power grid environments.

[0064] The passive energy storage and control circuit of this invention supports two extended control modes to adapt to different application scenarios: 1. Multi-channel integrated mode: By integrating multiple polarity switching output units within a single circuit, with each polarity switching output unit constituting one channel, multiple channels share the control logic unit and energy storage unit, achieving centralized control of 'single power input + multiple outputs'. This eliminates the need for an external pulse transmitter, resulting in compact installation and lower energy consumption. The energy storage unit's capacitor capacity needs to be designed based on the maximum number of solenoid valves that can be driven simultaneously, ensuring that the energy requirements for synchronous switching of all channels are met, or designed according to the maximum energy requirements of a single channel. By using the control logic unit to drive each channel in a time-sharing manner, the requirements for the energy storage capacitor capacity are reduced.

[0065] Furthermore, the MCU in this mode can be equipped with a button module to achieve independent control of a single channel, group control, and centralized control of all channels. For example, for a configuration with 4 channels, 4 independent channel buttons and 1 function button can be set. Pressing the corresponding channel button controls the opening and closing of the solenoid valve of that channel; pressing the function button and the corresponding channel button simultaneously enables centralized start and stop of that group of channels; in addition, unified on / off control of all channels can be achieved directly through power on / off operation, making operation convenient. Simultaneously, a bus data interface can be added to connect to a bus networking system, enabling remote control functionality and expanding the control range.

[0066] 2. Bus Networking Mode: Multiple independent passive energy storage and control circuits can be networked and controlled via mainstream data buses such as RS485, CAN, and Modbus. A single master controller manages them all, and each slave controller (i.e., each independent passive energy storage and control circuit) is assigned a unique address, enabling precise address-based control. This mode supports long-distance transmission and unified management of multiple distributed solenoid valves. It features stable command transmission, strong anti-interference capabilities, and is effectively adaptable to complex application scenarios such as large industrial systems and multi-area valve groups. Simultaneously, the master controller can monitor the real-time operating status of each slave controller (e.g., energy storage capacitor voltage, solenoid valve operating status, fault information, etc.), enabling remote debugging, fault warning, and centralized management, further improving the intelligence level of system control and reducing on-site maintenance costs.

[0067] Furthermore, the voltage conversion unit is optional, and its selection principle is as follows: when the external power supply voltage matches the rated operating voltage of the bistable solenoid valve coil, no voltage conversion unit is needed; when the external power supply voltage does not match the rated operating voltage of the solenoid valve coil, a voltage conversion unit is configured. The voltage conversion unit is configured to selectively operate in boost mode, buck mode, or direct / quiet mode based on the relationship between the external power supply voltage and the rated operating voltage of the solenoid valve coil, specifically: 1. Boost Mode: When the external input voltage is lower than the rated operating voltage of the solenoid valve coil, the voltage conversion unit operates in boost mode to boost the input voltage to the operating voltage range of the solenoid valve coil, while reducing the capacity requirement of the energy storage unit. 2. Buck Mode: When the external input voltage is higher than the rated operating voltage of the solenoid valve coil, the voltage conversion unit operates in buck mode to reduce the input voltage to the operating voltage range of the solenoid valve coil, while also reducing the voltage withstand requirements of the energy storage unit. 3. Through / Silent Mode: When the external input voltage matches the rated operating voltage of the solenoid valve coil, the voltage conversion unit operates in through mode; in conjunction with pulse charging of the energy storage unit or active control by the MCU, the voltage conversion unit enters a silent state when the energy storage unit has no charging requirement, reducing static power consumption.

[0068] The voltage conversion unit mainly consists of a DC-DC power management integrated circuit chip and its peripheral circuits. Depending on the operating mode, a corresponding DC / DC boost chip or DC / DC buck chip is selected, preferably a chip with high conversion efficiency, low static power consumption, and chip select functionality, ensuring low power consumption during energy storage and maintenance. Through the configuration of the voltage conversion unit, a wide range of power supply voltage adaptation can be achieved, specifically including: driving high-voltage rated solenoid valve coils with ultra-low DC voltage (e.g., DC 3.3V, DC 5V) and driving low-voltage rated solenoid valve coils with high DC voltage (e.g., DC 24V). Simultaneously, by adding a rectifier bridge and filter capacitor to the power interface unit, a wide range of AC24V~AC220V AC power supply access can be achieved. The voltage conversion unit converts the rectified DC voltage of the AC power supply into the appropriate voltage for the solenoid valve coil, achieving near-zero power consumption control driven by AC power.

[0069] Furthermore, the energy storage unit includes at least one capacitor. The charging circuit of the capacitor is connected in series with a unidirectional conductive diode, which limits the capacitor to discharge only through the polarity switching output unit. It serves as the energy storage carrier for the passive energy storage and control circuit, used to store electrical energy when the external power supply is turned on and to release electrical energy when the external power supply is turned off. The capacitance of the energy storage unit must satisfy the following relationship: C≥2Emin / U², where: Emin is the minimum energy required to drive the bistable solenoid valve core to complete one steady-state switching, and U is the rated charging voltage across the energy storage capacitor.

[0070] The Emin value can be obtained through formula calculation or actual testing. The formula calculation uses Emin = 1 / 2 * L * I², where L is the inductance of the solenoid valve coil based on the valve body, and I is the rated current of the coil required to drive the valve core switching. Actual testing can be performed using specialized equipment to detect the minimum energy requirement for switching the valve core of different specifications of solenoid valves. The specific value of Emin depends on the number of turns of the solenoid valve coil, the wire diameter, the iron core stroke, and the magnetic force of the permanent magnet. To accommodate non-ideal factors in actual engineering applications, such as the capacitance tolerance (usually ±20%), capacitance decay after long-term use, the influence of ambient temperature on capacitor performance, and energy loss in the drive circuit, a safety margin is introduced based on the theoretical capacitance calculated according to the formula. The preferred range of the safety margin is 1.5 to 5 times the theoretical calculated value. In special cases, it can be appropriately reduced, but it must be ensured that the energy stored in the capacitor is at least sufficient to reliably drive the valve core to complete one switching from one steady-state position to another, and this requirement must be met throughout the entire service life of the solenoid valve. In particular, those skilled in the art should understand that when the control circuit needs to be integrated into a space-constrained environment such as a solenoid valve junction box, a compact capacitor (such as a solid capacitor or a multilayer capacitor) with the same capacity or that meets the requirements of the above formula can be selected to achieve a miniaturized design of the control circuit.

[0071] Furthermore, the formula for calculating the capacitor capacity of the energy storage unit based on the extended multi-channel integration mode is as follows: Ct ≥ (n * 2 * Emin) / U² * Kf, where n is the maximum number of valves to be synchronously driven, Kf is the safety margin factor (e.g., 1.5~5), U is the charging voltage of the capacitor, and Ct is the capacity of the energy storage capacitor. If time-sharing drive technology is used, the Emin value of the valve requiring the maximum switching energy among all valves to be driven is used, but based on the requirement of synchronous shutdown during power outage, the total capacity is preferred.

[0072] The capacitor is a low-leakage capacitor, and its leakage power consumption is controlled to near-zero level (e.g., below 1.5mW) under the rated charging voltage U. However, considering that energy storage capacitors (such as some low-cost electrolytic capacitors) inherently have relatively large leakage currents in practical applications, the magnitude of the leakage current directly affects the energy replenishment strategy required to maintain the voltage. For capacitors with relatively large leakage power consumption, this invention preferably provides a circuit technology solution of "pulse power replenishment + hardware hysteresis", which has extremely low static power consumption (e.g., 1.5mW) to ensure the near-zero power consumption requirement of the maintenance step. The working principle logic of this power replenishment mechanism is as follows: (1) Monitoring: The voltage across the energy storage capacitor is monitored in real time by a voltage comparator with hysteresis characteristics.

[0073] (2) Judgment: When the leakage current of the energy storage capacitor is large, causing the voltage to drop to the first preset threshold, the comparator flips and triggers a very short charging pulse (e.g., 1ms-10ms) to replenish energy; (3) Recovery: When the voltage rises back to the second preset threshold, the comparator is reset, charging stops, and the circuit enters sleep mode again.

[0074] It should be noted that whether or not this power-up mechanism is activated depends on the selection of the energy storage capacitor: if an energy storage element with extremely low leakage current is used (such as certain solid-state capacitors or high-quality electrolytic capacitors, whose leakage current is < 5μA, and whose leakage power consumption meets the near-zero power consumption requirement), then the above power-up circuit does not need to be activated, and the system can achieve absolute "zero power consumption" maintenance. If a lower-cost but higher-leakage electrolytic capacitor is used (whose leakage current may reach 100μA-500μA, or even higher), then the above power-up circuit is activated. Because this circuit only operates for a very short time and has an extremely low duty cycle, its average power consumption is only about 1.5mW, which is still considered near-zero power consumption in engineering applications.

[0075] When selecting capacitors, it is also necessary to meet the withstand voltage requirements. The rated withstand voltage of the capacitor must be greater than or equal to its working voltage to prevent the capacitor from being broken down. At the same time, capacitors with low ESR (equivalent series resistance) and good temperature characteristics should be preferred to ensure energy storage and discharge efficiency.

[0076] Furthermore, the polarity switching output unit includes an H-bridge circuit, which is the core structure for realizing the polarity switching of the drive current pulse. It includes four switching devices and four freewheeling diodes. The four switching devices are Q01 (upper left arm), Q02 (lower left arm), Q03 (upper right arm), and Q04 (lower right arm), and can be made using transistors or MOSFETs. The H-bridge circuit is connected as follows: one end of the upper arms Q01 and Q03 of the four switching devices is interconnected and electrically connected to the positive terminal of the energy storage unit; one end of the lower arms Q02 and Q04 is interconnected and electrically connected to the negative terminal of the energy storage unit. The connection point between Q01 and Q02 is point A, and the connection point between Q03 and Q04 is point B. Points A and B are electrically connected to the two ends of the bistable solenoid valve coil, respectively. Each switching device has a freewheeling diode connected in reverse parallel across its two ends to absorb the reverse electromotive force of the coil and protect the switching device. The selection of the four freewheeling diodes matches the specifications of the switching devices to ensure rapid absorption of the reverse electromotive force.

[0077] The H-bridge circuit employs a control logic where diagonal switches are simultaneously turned on and off. Software programming prevents all four switches in the H-bridge circuit from conducting simultaneously. The initial operating state and the default operating state during the maintenance phase of the MCU are both in the zero-power off state of the H-bridge circuit. Specifically, the MCU in the control logic unit implements the logic control, using a "diagonal switches simultaneously turned on and off" control method. Q01 and Q04 form one group, and Q03 and Q02 form another. Both groups of switches can be turned off simultaneously, but are absolutely not allowed to be turned on simultaneously to prevent short circuits in the energy storage unit. The MCU outputs two control signals to the polarity switching output unit. The combination of these two control signals forms four states (00 / 01 / 10 / 11), where "1" indicates that the switch is on, forming a circuit, and "0" indicates that the switch is off, breaking the circuit. Software programming avoids the occurrence of the "11" state. The initial state and the default state during the maintenance phase of the MCU are both "00," at which point all four switches are off, and the H-bridge circuit enters a zero-power state. The specific working process is as follows: 1. When the MCU outputs a control signal of "10", Q01 and Q04 are turned on, and Q03 and Q02 are turned off. The electrical energy released by the energy storage unit forms a loop through Q01-point A-solenoid valve coil-point B-Q04, generating a drive current pulse in the first direction, which drives the valve core to switch to the first steady-state position. 2. After the first direction drive current pulse is output, the MCU switches the control signal to "00", all four switching devices are turned off, and the H-bridge circuit returns to zero power consumption. 3. When the MCU detects that the external power supply is disconnected and outputs a control signal of "01", Q03 and Q02 are turned on, and Q01 and Q04 are turned off. The electrical energy released by the energy storage unit forms a loop through Q03-point B-solenoid valve coil-point A-Q02, generating a drive current pulse in the second direction, which drives the valve core to switch to the second steady-state position. 4. After the second direction drive current pulse is output, the MCU switches the control signal to "00" again, and the H-bridge circuit returns to the zero power consumption state.

[0078] Furthermore, the power interface unit includes a reverse connection protection module, an overvoltage protection module, and an overcurrent protection module. The reverse connection protection module uses a reverse connection protection circuit composed of MOSFETs or a diode rectifier bridge; the overvoltage protection module uses a TVS transient voltage suppressor diode matched to the input voltage; and the overcurrent protection module uses a PPTC resettable fuse. The power interface unit serves as the power input terminal for the passive energy storage and control circuit, providing polarity protection, overvoltage protection, and overcurrent protection for the external power supply, and can also assist in power on / off detection.

[0079] For DC power input, a reverse connection protection circuit composed of MOSFETs is preferred to achieve lower near-zero power consumption; for AC power input, a diode rectifier bridge is used to achieve rectification, filtering and reverse connection protection.

[0080] The power interface unit is specifically configured as follows: a TVS transient voltage suppressor diode matched to the input voltage is connected in parallel at the input terminal to achieve overvoltage protection and absorb surge voltage; a PPTC self-resetting fuse is connected in series at the output terminal to achieve overcurrent protection, which automatically disconnects in case of short circuit or overload and automatically recovers after the fault is cleared.

[0081] Two voltage divider series resistors and a protection TVS diode can be connected in parallel at the output terminal, with the midpoint of the resistors serving as the on / off monitoring point. This can be used in conjunction with the MCU pin of the control logic unit to achieve power on / off detection. This application prioritizes the use of the voltage monitoring module of the control logic unit in conjunction with the MCU to complete the on / off detection, so as to further reduce the power consumption during the maintenance phase and achieve a better zero-power effect.

[0082] The downlink connection method of the power interface unit is adjusted depending on whether a voltage conversion unit is configured: 1. Without a voltage conversion unit, the output of the power interface unit is connected in two ways: one way is electrically connected to the energy storage unit through a unidirectional conductive diode to charge the energy storage unit; the other way is electrically connected to the DC-DC chip of the control logic unit to supply power to the control logic unit. 2. When a voltage conversion unit is present, the output terminal of the power interface unit is electrically connected to the voltage conversion unit, and the output terminal of the voltage conversion unit is electrically connected to the input terminal of the storage unit. If the output terminal of the power interface unit does not match the input voltage of the DC-DC chip of the control logic unit, a parallel connection is made from the output terminal of the voltage conversion unit to the DC-DC chip of the control logic unit. Preferably, the output terminal of the power interface unit serves as the input of the DC-DC chip of the control logic unit.

[0083] 3. There are three connection schemes for the status control pin of the voltage conversion unit: First, if there is a pulse compensation module, the pin is directly electrically connected to the output terminal of the pulse compensation module; second, if there is no pulse compensation module, the pin can be electrically connected to the pin of the MCU that controls the operating status of the voltage conversion unit, and the operating status of the voltage conversion unit is controlled by the MCU; third, according to the chip requirements, the voltage conversion unit is always in the operating state through a pull-up resistor or a pull-down resistor.

[0084] Furthermore, during the maintenance step, the bistable solenoid valve coil is completely de-energized, and all units of the passive energy storage and control circuit enter a silent maintenance state. The overall circuit is under ultra-light load or zero physical load, and the power consumption of each unit is strictly controlled. Taking a DC24V power input as an example, the power consumption of each unit is as follows: - Power consumption of the power interface unit: 1.5mW; - Power consumption of the energy storage unit: If the capacitor leakage current is 10uA, the power consumption is 0.24mW or the pulse compensation power consumption is 1.5mW; - Power consumption of the control logic unit: DC-DC conversion 0.015mW, power supply voltage monitoring 0.006mW, MCU power-down mode operation 0.003mW, total 0.024mW; - The four switching devices of the H-bridge circuit of the polarity switching output unit are all in the off state, and the power consumption is infinitely close to 0mW; - If a voltage conversion unit is configured, the power consumption in boost or buck mode can be controlled to around 0.3mW; - The total power consumption of each unit is less than 5mW, achieving true zero power consumption maintenance; If the input DC power supply voltage is lower than DC24V, such as DC12V, the static power consumption of each unit will be further reduced, resulting in better energy efficiency.

[0085] Beneficial effects The near-zero power consumption control method for bistable solenoid valves of this invention, through a three-step design of triggering, execution, and maintenance, combined with passive energy storage and control circuit hardware implementation, overcomes inherent technical biases in the industry. It organically combines the extremely simple control method of direct-acting monostable solenoid valves with the zero-power consumption maintenance characteristics of bistable solenoid valves, while simultaneously solving common industry problems such as poor voltage adaptability, complex control, high power consumption, and high cost of solenoid valves. Compared with existing technologies, this invention has the following significant advantages: 1. The control logic is extremely simple, greatly improving the user experience. This invention can switch the bistable solenoid valve core state simply by switching on and off an external power source. No additional control signals are required, and there is no need to configure external pulse generating devices such as PLCs or dedicated drive boards. The control method is completely consistent with that of traditional direct-acting monostable solenoid valves. Users do not need to change their usage habits, which significantly lowers the threshold for using bistable solenoid valves, transforming them from professional control components into general-purpose and easy-to-use actuators.

[0086] 2. Truly achieves near-zero power consumption standby, with outstanding energy-saving effect. After the valve core state switching is completed, the solenoid valve coil is completely de-energized, and its position is locked by its own magnetic holding structure; the passive energy storage and control circuit simultaneously enter a low-power silent state. With a DC input of 3.0V~40V, the total power consumption is less than 5mW, meeting the zero standby power consumption requirement of the IEC 62301 standard; with an AC input of 24V~220V, the total power consumption does not exceed 80mW. Compared to the continuous power consumption of traditional monostable solenoid valves and the power consumption of external devices in traditional bistable systems, the energy saving rate exceeds 90%, fundamentally avoiding problems such as long-term coil overheating and aging, and decreased reliability.

[0087] 3. Wide voltage range compatibility, significantly reducing production and usage costs. With a selectable voltage conversion unit, it achieves wide-range power supply adaptability from DC 3.0V to DC 40V and AC 24V to AC 220V, and the same solenoid valve coil is compatible with all voltage specifications. Manufacturers only need one coil to cover the entire series of voltage products without changing the valve body structure, significantly reducing mold, R&D, production and inventory costs; users do not need to provide a dedicated matching power supply, greatly improving the equipment's versatility and interchangeability.

[0088] 4. High circuit integration, simple and convenient installation and maintenance. The passive energy storage and control circuit can be compactly integrated inside the solenoid valve junction box, with only a two-wire input and two-wire output structure. It can directly replace the traditional junction box, realizing an integrated design of the solenoid valve without occupying additional installation space. The circuit has built-in reverse connection protection, overvoltage protection, and overcurrent protection functions. Fault points are concentrated, and troubleshooting is simple, greatly reducing the workload of on-site installation, commissioning, and subsequent operation and maintenance.

[0089] 5. Built-in coil fault diagnosis and visual indication significantly improve system maintainability. The control logic unit incorporates a drive circuit fault monitoring module, which monitors the voltage drop of the energy storage unit in real time within the pulse output time window. It can automatically identify open circuit faults such as broken solenoid valve coil wires, loose wiring, and open circuits, and outputs fault alarm signals via optocoupler isolation or reports fault codes via the bus, enabling preventative maintenance and rapid fault location. Simultaneously, a low-power LED fault indicator module is included, which illuminates only when a fault occurs and remains off during normal standby and operation, consuming no additional static power. This provides intuitive visualization of the fault status, significantly reducing the difficulty of on-site troubleshooting and maintenance.

[0090] 6. Stable and reliable drive, applicable to a wide range of valve types. The energy storage unit's capacitor capacity is calculated using a formula and a safety margin is reserved. It is used in conjunction with a unidirectional diode to limit the discharge path, ensuring the minimum driving energy required for valve core switching. The control logic unit can flexibly configure parameters such as pulse width and peak current to adapt to different models and power bistable solenoid valves. The H-bridge of the polarity switching output unit is equipped with a freewheeling diode to absorb the reverse electromotive force of the coil, and software logic is used to prevent bridge arm shoot-through, resulting in higher overall system stability and safety.

[0091] 7. The energy storage structure is rationally designed to strictly guarantee low power consumption characteristics. The energy storage unit can use low-leakage capacitors, with leakage power consumption not exceeding 1.5mW under rated voltage; and directional discharge is achieved through unidirectional diodes to avoid energy backflow loss. For high-leakage capacitors with lower cost, leakage can be automatically compensated through pulse compensation and hardware hysteresis closed-loop scheme, structurally ensuring near-zero power consumption during the maintenance phase and preventing excessive power consumption due to capacitor leakage.

[0092] 8. Supports high leakage current and low cost capacitors, significantly reducing material costs. This invention can directly use lower-priced and more versatile high-leakage electrolytic capacitors. Through pulse power compensation and hardware hysteresis mechanism, the material cost can be reduced by 30% to 50% without sacrificing zero-power performance. This breaks through the limitation of existing technology that must use high-priced, low-leakage capacitors, and greatly improves the product's cost performance and market competitiveness.

[0093] 9. Pure hardware nanosecond-level response, meeting the needs of high-speed control scenarios. It adopts pure hardware hard-wired logic, abandons the traditional MCU software scanning method, eliminates the lag caused by interrupt delay and instruction execution cycle, and the signal transmission delay reaches the nanosecond level, which is negligible compared to the millisecond-level mechanical action of the solenoid valve. This allows the solenoid valve to respond to commands at the physical limit speed, meeting the requirements of high-speed and high-precision fluid control scenarios.

[0094] 10. Supports multi-channel centralized control, resulting in higher system integration. The circuit supports multi-channel integration mode, with multiple output channels sharing the same set of control logic and energy storage unit, realizing "single power input, multiple pulse outputs". It eliminates the need for an external pulse generator, simplifies wiring, reduces energy consumption, and is suitable for centralized control of multiple valves within the same device, reducing system complexity and cost.

[0095] 11. Supports local button control, making on-site debugging more convenient. It can expand the local button unit to realize independent manual control of single channel, group, and full channel. It can be directly operated on site in scenarios without bus or PLC, which is convenient for debugging, maintenance and emergency control, and eliminates the dependence on external equipment.

[0096] 12. Supports bus-networked distributed control with extremely high scalability. Multiple independent drive circuits can be networked via buses such as RS485, CAN, and Modbus, and managed uniformly by the master controller. Each slave device has an independent address, enabling centralized control, remote configuration, and status monitoring of remotely distributed solenoid valves. This is suitable for large industrial systems and complex application scenarios with multiple valve groups.

[0097] 13. High adaptability to modification and low cost of industrialization. This control method can be directly applied to the upgrade and transformation of existing bistable solenoid valves without redesigning the valve body structure. The transformation cost is low and the cycle is short. It can quickly form a full range of zero-power / ultra-low-power solenoid valve products for DC3.3V / 5V / 12V / 24V and AC24V / 110V / 220V, filling a gap in the industry.

[0098] 14. It has a wide range of applications and a huge market potential. It can be widely used in many fields such as industrial automation, fluid control, hydrogen energy equipment, smart home, smart water management, agricultural irrigation, HVAC, and passive standby pipeline control. It has strong versatility, wide market coverage, and great value for industrialization and promotion.

[0099] The voltage adaptation range of this invention is a preferred example and is not a limitation on the scope of protection. Any core concept that adopts power on / off triggering, passive energy storage drive, pulse polarity switching, near-zero power consumption maintenance, and wide voltage adaptation, regardless of how the input voltage is conventionally extended beyond the preferred range, falls within the scope of protection of this invention.

[0100] The core parameters of this invention are compared with those of existing technologies as follows: Comparison Dimensions Monostable solenoid valve Traditional bistable solenoid valve (external pulse) This invention Control method Power on / off, simple External pulse generator, complex Power supply switching is consistent with monostable state. Maintain power consumption 5W~30W, continuous power consumption External device power consumption > 1W DC<5mW / AC≤80mW Voltage adaptability Single voltage, requires custom coil Single voltage, coil strongly bonded to power supply DC3.0~40V / AC24~220V, single coil Integration The main body has no control circuit. External driver board, large size The control circuit is integrated into the junction box, making it a single unit. Coil Specifications Multiple specifications to adapt to different voltages Multiple specifications to adapt to different voltages Single specification, compatible with the entire voltage range Another significant advantage of this invention lies in its role as the fundamental control unit of the applicant's core technology system of "passive control and intelligent diagnosis of bistable solenoid valves." It not only solves the problem of independent drive of a single coil but also forms the cornerstone of the "passive control and intelligent diagnosis system." Its design intent and technical features allow for seamless collaboration with other core technology modules developed by the applicant, achieving a system value of "1+1>2." (1) Collaboration with the control and diagnostic module: The ultra-low standby power consumption of the present invention provides an excellent static working window for the "A Bistable Solenoid Valve Fault Diagnosis Method and Device" based on real-time current and power consumption monitoring, so that the diagnostic process is free from energy interference and the data benchmark is clear, thereby enabling high-precision capture of early micro-motion faults such as valve core aging and adhesion.

[0101] (2) Collaboration with the valve island drive system: The minimalist "two-line input, two-line output" architecture of this invention provides an ideal underlying drive unit for "A Smart Valve Island Control Method and Device with Multi-channel Common Power Supply Drive and Independent Diagnosis", enabling a single control module to efficiently integrate and manage multiple valves while maintaining independent diagnostic capabilities. This greatly simplifies the design and wiring of complex multi-valve control systems and realizes a "smart valve island" system that integrates clustered management, energy saving and intelligent diagnosis.

[0102] (3) Synergy with passive energy replenishment scheme: The energy storage capacitor and low power consumption control logic of the present invention provide a natural energy container and control trigger point for the "Pulse replenishment method and device for a passive energy storage circuit". The combination of the two can form a complete "energy storage-drive-replenishment" energy self-closed loop system, which can maintain reliable drive energy reserves for a long time.

[0103] Therefore, this application is not only an innovative single drive controller, but also a key hub that connects the complete technology chain of 'simplified control - energy-saving operation - intelligent maintenance - energy self-sufficiency', and has extremely high system integration value and broad application potential.

[0104] Creative explanation

[0105] The technical solution of this application is not a simple combination or conventional improvement of existing technologies, but a groundbreaking invention that breaks through the long-standing inherent technical prejudices in the industry and solves a number of long-standing technical pain points. It has outstanding substantive features and significant progress in the sense of patent law, and its inventiveness is fully demonstrated and conclusive.

[0106] I. Overcoming multiple technological biases in the industry, the direction of innovation is not obvious. 1. Break the technical prejudice that "bistable solenoid valves must rely on external pulse generators".

[0107] The industry generally believes that bistable state switching requires external devices such as PLCs and dedicated driver boards to provide polarity pulses. This application, through the integrated design of passive energy storage and control circuits, uses power on / off as both energy supply and control commands, achieving extremely simple "power on, power off" control, completely eliminating the need for external pulse devices, and overturning industry consensus.

[0108] 2. Break the technological prejudice that "energy supply and control commands must be transmitted separately".

[0109] Traditional solutions require separate wiring for power supply and control. This application is the first to realize a two-wire system that can simultaneously carry energy and commands. Power on / off = trigger signal = commutation pulse, unifying energy flow and control flow at the physical layer, which is a fundamental innovation.

[0110] 3. Break the technical prejudice that "zero power consumption maintenance must use low leakage current and high cost capacitors".

[0111] Conventional techniques suggest that only extremely low leakage capacitance can achieve near-zero power consumption. This application utilizes a pulse-compensation + hardware hysteresis comparison closed-loop mechanism to enable low-cost, high-leakage electrolytic capacitors to stably maintain near-zero power consumption of ≤1.5mW, achieving an unexpected technical effect in balancing cost and performance.

[0112] 4. Break the technical prejudice that "one coil can only be adapted to one power supply voltage".

[0113] The industry has long adopted the "one voltage for one coil" approach. This application achieves full-range input compatibility of a single coil with DC3V~40V and AC24V~220V by means of wide voltage adaptive + automatic switching between boost / buck / silent modes, without the need to change the valve body structure, thus significantly reducing production and usage costs.

[0114] The aforementioned biases are repeatedly reinforced by industry standards, authoritative manuals, and mainstream patent literature, constituting strong reverse technical inspiration. This application completely breaks through these constraints, and the direction of innovation itself possesses a high degree of non-obviousness.

[0115] Second, core technical solutions require creative work and are not simply a combination of modules. 1. Innovative overall architecture for power-on / off triggered bistable commutation This requires simultaneously addressing a series of collaborative issues, including energy storage timing, power-down pulse generation, logic maintenance, polarity switching, and zero-power quiescent. The units are strongly coupled and indivisible, unlike the conventional combination of MCU, H-bridge, and capacitors. Traditionally, this combination is only used for complex timing control. Applying it to implement the extremely simple instruction of "power on / off" while collaboratively solving wide voltage range and zero-power issues presents significant technical hurdles to overcome, such as power-down timing control, ultra-low power maintenance, and balancing efficiency and static power consumption under wide voltage range adaptation.

[0116] 2. Pure hardware nanosecond-level high-speed response solution By eliminating the microsecond to millisecond delay caused by MCU software scanning, and adopting hard-wired logic of power detection + logic control + pulse timing + energy maintenance, the signal delay is less than 100ns, enabling the solenoid valve to reach the physical limit of response speed. This is an original design for high-speed control scenarios.

[0117] 3. Near-zero power consumption maintenance mechanism with high leakage capacitance It is necessary to accurately set key parameters such as hysteresis window, compensation pulse width, duty cycle, and voltage threshold to ensure sufficient driving energy while reducing average power consumption to an extremely low level. There are no conventional formulas to apply, and it is necessary to rely on a lot of experiments and creative design.

[0118] 4. Dynamic sampling-based fault diagnosis (zero additional standby power consumption) The sampling circuit is instantaneously activated within the pulse window and completely disconnected during standby, enabling automatic identification of coil open circuits, broken wires, and poor contact, without increasing any static power consumption. This is an original design in the field of low-power electronics.

[0119] Third, existing technologies offer no inspiration for integration, and the direction of innovation has not been foreseen. The prior art related to this application is fragmented: • External pulse drive only solves bistable commutation, without integration, wide voltage range, or energy storage for power replenishment; • Wide voltage schemes are only applicable to monostable states and cannot achieve zero-power retention; • Capacitor energy storage technology relies solely on low leakage characteristics and lacks a high leakage compensation mechanism; • Junction boxes are for protection only and have never integrated complete drive and control logic.

[0120] There is no existing technology that integrates "power on / off triggering, passive energy storage, wide voltage adaptive, pulse power replenishment, pure hardware high speed, and low power fault diagnosis" into one technology. This application belongs to cross-domain and highly collaborative integrated innovation.

[0121] Fourth, the absence of similar products in the market confirms the non-obviousness. As of the date of this application, no product worldwide has simultaneously achieved: two-wire on / off control + bistable near-zero power consumption + wide voltage adaptive capability + pure hardware high-speed response + universal low leakage current / high leakage current capacitance + automatic coil fault diagnosis.

[0122] This is not due to insufficient demand, but rather because technological bias and fundamental barriers have prevented the industry from making breakthroughs in the long term, further confirming that this application is not obvious.

[0123] V. Conclusion This application breaks through technical bias, solves long-standing problems, achieves unexpected technical effects, has an original overall structure, and is not inspired by existing technologies. It fully meets the inventiveness requirements of the Patent Law for invention patents, namely "prominent substantive features and significant progress", and possesses sufficient and solid inventiveness. Attached Figure Description

[0124] The present invention will be further described below with reference to the accompanying drawings and embodiments. Figure 1. General control architecture of near-zero power consumption controller for bistable solenoid valves Figure 2. Schematic diagram of the overall circuit structure based on the MCU solution (with voltage conversion unit) Figure 3. Schematic diagram of the control logic unit circuit (based on MCU) Figure 4. Schematic diagram of the control logic unit circuit (based on pure hardware logic) Figure 5. Schematic diagram of the overall circuit structure of the voltage-free conversion unit. Figure 6. Schematic diagram of the power interface unit circuit. Figure 7 Schematic diagram of boost mode voltage conversion unit circuit Figure 8. Schematic diagram of buck mode voltage conversion unit circuit. Figure 9 Schematic diagram of energy storage unit circuit Figure 10 Schematic diagram of polarity switching output unit (H-bridge) Figure 11 Multi-channel local button control architecture diagram Explanation of reference numerals in the attached figures: 100 power interface units, 200 voltage conversion units, 300 energy storage units, 400 polarity switching output units. 500 Control Logic Unit, 501 Pulse Drive Control Module, 510 Power Status Detection Module, 521 Power On / Off Monitoring Line (Optional), 520 Power On / Off Monitoring Line; DC+ and DC− external power input terminals, 101 reverse connection protection module, 104 overvoltage protection module (TVS), 103 overcurrent protection module (PPTC), 102 resistor divider power continuity detection module. In the diagram, DC- and GND are at the same potential point; 201 Boost mode voltage conversion unit, 202 Buck mode voltage conversion unit, Ve1 Boost mode control pin, Ve2 Buck mode control pin, V1 Power interface unit output voltage, V2 Voltage conversion unit output voltage; Cx is the energy storage capacitor, D3 is the unidirectional conducting diode, 302 is the pulse compensation + hardware hysteresis module, 303 is the electronic switch module, Vp is the compensation pulse output terminal, Vc is the electronic switch control terminal, V3 is the output voltage of the energy storage unit, and Cx_V+ is the positive terminal voltage of the energy storage capacitor Cx. Q01, Q02, Q03, Q04 H-bridge switching devices; D01, D02, D03, D04 freewheeling diodes; X1, X2 coil output interfaces; CT1, CT2 control signal terminals; midpoints of A and BH bridge arms. 502 DC power supply module, 503 voltage monitoring module, 504 MCU module, 505 power reference monitoring module, 506 monostable pulse module, 507 steady-state trigger module, 508 dual AND gate logic module, 509 local keypad input unit, 511 general data communication interface, Cy logic power supply sustaining capacitor, D101 isolation diode, VCC logic power supply voltage; CH0, CH1, CH2, CH3, CHn output channels; 400 CH0~400 CHn multi-channel polarity switching output unit; 512 Fault Diagnosis Module, 513 Fault Indication Module; Note: The dotted line outline in the illustration is an optional design feature. Detailed Implementation

[0125] The technical solution of the present invention will be described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and are not intended to limit the scope of protection of the present invention. The core components in the embodiments are preferred models, and the present invention is not limited to these model selections.

[0126] Example 1: A general control architecture for a near-zero power consumption controller for a bistable solenoid valve like Figure 1 As shown, this embodiment provides a general control architecture for a near-zero power consumption controller for a bistable solenoid valve. The controller includes a passive energy storage and control circuit (including a power interface unit 100, an optional voltage conversion unit 200, an energy storage unit 300, a polarity switching output unit 400, and a control logic unit 500), with the control logic unit 500 being the core component.

[0127] The control logic unit is internally divided into a power status detection module 510 and a pulse drive control module 501.

[0128] The input terminal of the power status detection module 510 is electrically connected to the 102 resistor voltage divider continuity detection module of the power interface unit 100 (connection line 521 in the figure), or electrically connected to the output of the DC-DC power supply module 502 (connection line 520 in the figure), for real-time monitoring of the continuity status of the external power supply (e.g., monitoring the presence or drop of voltage) and outputting a logic level signal.

[0129] The input terminal of the pulse drive control module 501 is connected to the output terminal of the power status detection module 510, and its output terminal is connected to the control terminal of the polarity switching output unit 400 (such as an H-bridge circuit) (connection line 522 shown in the figure).

[0130] During operation, once the power status detection module 510 detects a power-on or power-off edge signal, the pulse drive control module 501 generates a corresponding polarity switching control signal according to preset logic, controlling the energy storage unit 300 to release a drive current pulse in a specific direction to the solenoid valve coil. This embodiment does not limit the specific circuit implementation; any circuit architecture that can implement the above-mentioned "detection-control" logic falls within the protection scope of this embodiment.

[0131] Example 2: Control Logic Unit Based on MCU Control Scheme This embodiment is a specific hardware implementation of the control logic unit in Embodiment 1. The control logic unit uses a microcontroller (MCU) as the core control device.

[0132] 1. GPIO pin assignment and function definition: The MCU has at least four programmable composite function GPIO pins, and their specific connection relationships are as follows: Power detection pin (at least 1): Used to detect power on / off (connection line 523 shown in the diagram).

[0133] Drive control pins (at least 2): Used to output high / low level control signals to the polarity switching output unit (H-bridge) to control the current direction. (See diagram for connection lines 522, CT1 / CT2) Power management pin (optional 1 channel): Used to output control signal 524 to control the voltage conversion unit to be in operation mode or silent mode to further reduce power consumption. (See diagram for connection line 524).

[0134] 2. Two specific implementations of power supply detection: Option A (Dedicated Monitoring Chip): A voltage monitoring module (such as a reset chip or dedicated voltage detection IC) is used to monitor the power supply and output a reset signal to the MCU's interrupt pin. The diagram shows connection line 520.

[0135] Option B (Simplified Voltage Divider Detection): As another simplified option, the midpoint of two series-connected voltage divider resistors is used as the detection point in the power interface unit and directly connected to the MCU's GPIO pin (i.e., the aforementioned power detection pin). The MCU uses its internal ADC or comparator to read the voltage change at this pin to determine power on / off. While this option omits a dedicated voltage monitoring module, reducing BOM costs, the voltage divider resistors introduce microamp-level static power consumption. Users can choose between "ultra-low power consumption" and "low cost" based on their application scenario. The diagram shows connection line 521.

[0136] 3. Specific circuit for fault diagnosis (dynamic sampling): To achieve fault diagnosis under low power consumption, this embodiment, as shown in the fault diagnosis module 512 in Figure 512, employs a dynamic sampling circuit connected to the ADC pin of the MCU. This circuit includes an NPN transistor Q4 (or an NMOS transistor) and a high-resistance resistor voltage divider network (R20 / R21).

[0137] Connection method: One end of the voltage divider network is connected to the positive terminal Cx_V+ of the energy storage capacitor, and the other end is connected to the ADC pin of the MCU through a transistor. The base of the transistor is connected to a GPIO control pin of the MCU.

[0138] Working Principle: In standby mode, the MCU controls the GPIO to output a low level, the transistor is cut off, the voltage divider network is disconnected from the MCU, and the static power consumption is almost zero. When the MCU issues a drive pulse command (such as a 40ms window), the GPIO outputs a high level momentarily to turn on the transistor, and the ADC starts sampling the energy storage capacitor voltage. If the sampled voltage drop value ΔV is less than the threshold, the MCU determines that there is an open circuit fault in the coil, first saves the fault information in the MCU's EEPROM, and then lights up an LED alarm light through another GPIO, reports the fault through the communication interface, or displays a local LED indicator on the next power-on (see fault indication module 513).

[0139] Example 3: Control Logic Unit Based on Pure Hardware Control Scheme This embodiment is another specific hardware implementation of the control logic unit in Embodiment 1, which aims to solve the potential software runaway risk and startup delay problem of the MCU solution.

[0140] This embodiment provides a pure hardware implementation scheme that does not rely on a microcontroller (MCU) to replace the control logic unit and polarity switching logic in Embodiment 1. Its core lies in using the timing coordination of analog circuits and logic gate circuits to achieve the "on / off control" method that is completely consistent with Embodiment 1.

[0141] Preferably, the time base circuit is implemented using a low-power TLC555 chip; the logic gate circuit is implemented using 74LVC1G74 and 74LVC2G08 chips; and the voltage reference circuit is implemented using a TL431 chip. Of course, those skilled in the art can also use other chips with the same function, such as LM555, LM556, CD4047, 74HC74, etc., all of which fall within the protection scope of this invention.

[0142] 1. Hardware architecture adjustment In this embodiment, the MCU module and voltage monitoring module in the control logic unit 500 are replaced by discrete hardware circuits, while the DC-DC power supply module is retained. The overall hardware architecture consists of a power reference monitoring module 505, a monostable pulse module 506, a steady-state trigger module 507, an AND gate logic module 508, and an energy maintenance module. All modules are connected in an integrated manner via a PCB. The specific structure is as follows: (1) Power reference monitoring module 505 The core component is the TL431 (T101 in the diagram), a three-terminal adjustable parallel voltage regulator consisting of a reference terminal R, an anode A, and a cathode K. The TL431's reference terminal R is connected to the midpoint of voltage divider resistors R101 and R102 for power supply voltage sampling; anode A is grounded; and cathode K is connected to the TRIG pin (pin 2) of the monostable pulse module 506, used to convert power on / off states into level transition trigger signals. This is used for real-time monitoring of the external power supply's on / off status.

[0143] (2) Monostable pulse module 506 The core is the NE555 timer chip. The TRIG pin (pin 2) is connected to the cathode K of the TL431; the RESET pin (pin 4) is connected to VCC; the OUT pin (pin 3) is connected to the CP clock terminal of the 507 steady-state trigger module; the timing terminals (pins 6 / 7) form an RC timing circuit with resistor R104 and capacitor C101 to set the pulse width; the chip's power supply is taken from both ends of the energy storage capacitor Cy. This is used to generate a fixed-width drive pulse.

[0144] (3) Steady-state trigger module 507 The core is a 74LVC1G74 D flip-flop, with its D pin shorted to its own / Q output (pin 5), forming a T flip-flop structure. The CP clock pin is connected to the OUT pin of the monostable pulse module 506. The / RD reset pin (pin 6) is connected to VCC, and the / SD set pin is connected to the midpoint of the power-on reset circuit R105 and C103 to ensure forced setting upon power-on, making Q=1 and / Q=0, while maintaining a normal state without resetting. The outputs Q (pin 3) and / Q (pin 5) are connected to the AND gate logic module 508. The chip's power supply is connected to the two ends of Cy. This is used to remember the state switching logic.

[0145] (4) AND gate logic module 508 The core is a 74LVC2G08 dual AND gate chip. One AND gate's input is connected to the Q output of the steady-state trigger module 507 and the OUT pin of the monostable pulse module 506, outputting control signal CT1. The other AND gate's input is connected to the / Q output of the steady-state trigger module 507 and the OUT pin of the monostable pulse module 506, outputting control signal CT2. CT1 and CT2 serve as control signal terminals for the subsequent polarity switching output unit, driving the H-bridge circuit to achieve solenoid valve polarity switching. This is used to generate the output of the state switching logic.

[0146] (5) Energy maintenance module The energy storage capacitor Cy is used to maintain the power supply energy of the control logic unit, and a capacitor with low leakage current is preferred; the isolation diode D101 (preferably 1N5819) is connected in series in the power supply circuit to achieve unidirectional power supply isolation and provide a sustaining power supply for the above logic circuit at the moment of power failure; VCC is the power supply voltage of the control logic unit, and DC- is the power supply reference ground.

[0147] 2. Working principle (corresponding methods and steps) (1) Triggering steps: When the external power supply is turned on or off, the change in power supply voltage causes the cathode K level of TL431 to jump, directly forming a trigger signal on the TRIG pin of NE555.

[0148] (2) Execution steps (power on): When the external power supply is turned on, VCC supplies power to the control circuit through the isolation diode D101 and charges the energy storage capacitor Cy at the same time; synchronously, the logic control module (stable trigger 507) recognizes the level change of the TRIG pin and flips the output state; the monostable pulse module (555, 506) is triggered to generate a pulse signal with a fixed width, which is output as a first direction drive pulse (CT1=1, CT2=0) after being logically combined by the AND gate module (508), driving the subsequent H bridge to make the current flow through the solenoid valve coil and complete the opening action.

[0149] (3) Execution steps (power off): When the external power supply is disconnected, the energy storage capacitor Cy maintains the power supply of the logic circuit briefly through the isolation diode D101 (1N5819); the change of the TL431 state causes the TRIG pin to generate a reverse level jump, and the logic control module (stable trigger 507) flips the output state again; the monostable pulse module (506) is triggered again, generating a fixed width pulse, which is output as a second direction drive pulse (CT1=0, CT2=1) after being logically combined by the AND gate module (508), and the residual energy of the energy storage capacitor Cy is used to drive the solenoid valve coil to reverse the action and complete the closing action.

[0150] (4) Maintenance steps: After the drive pulse ends, the output of the monostable pulse module (506) returns to zero, and the output of the AND gate module (508) is CT1=0 and CT2=0. All four switches of the H-bridge are turned off, completely cutting off the current path of the solenoid valve coil. At this time, the circuit only maintains the static operating current of the logic control unit (time base chip, flip-flop, logic gate, etc.). Under the preferred low-power device selection scheme, the static power consumption of the overall control circuit can be reduced to below 1mW, achieving a state maintenance of almost "zero power consumption".

[0151] 3. Basis for achieving a latency of less than 100ns: This embodiment uses pure hardware hard-wired logic, with no MCU or software execution delay. The response latency is the sum of the inherent transmission delays of each device, calculated using the following formula: T_total = T_TL431 + T_NE555 + T_74LVC1G74D + T_74LVC2G08; Power detection module (TL431): Typical delay 20ns; Pulse timing module (NE555 high-speed CMOS type): typical delay 30ns; Steady-state trigger (74LVC1G74D): Typical delay 18ns; AND gate logic module (74LVC2G08): Typical delay 12ns; Total delay calculation: T_total = 20 + 30 + 18 + 12 = 80ns < 100ns; It meets the nanosecond-level response requirements of high-speed control scenarios, and the signal delay is negligible compared to the millisecond-level mechanical action of the solenoid valve.

[0152] Performance advantages: Pure hardware logic with no software delay, response speed is much faster than MCU solutions, enabling solenoid valves to operate at physical limit speeds, meeting the extreme requirements of high-speed control scenarios.

[0153] This embodiment uses the power-on reset circuit (R105+C103) at the / SD terminal to ensure that the initial power-on state is strictly Q=1 and / Q=0, thus guaranteeing the consistency of the solenoid valve's action direction and using low-cost logic devices to construct the overall operating logic, which is a key creative design.

[0154] It should be noted that the pure hardware logic in this embodiment mainly achieves nanosecond-level high-speed response and extremely simple on / off control; if complex fault diagnosis functions are required, the MCU solution described in Embodiment 2 should be used first. The two solutions complement each other and cover different application scenarios.

[0155] Example 4: A DC24V power supply drives a DC24V bistable solenoid valve (without a voltage conversion unit). This embodiment uses a DC 24V power supply as the external power source to drive a single-coil bistable solenoid valve with a rated operating voltage of DC 24V. The passive energy storage and control circuit does not include a voltage conversion unit. Core component selection: STM32L011F4U6 MCU, 1N5819 unidirectional diode, SMBJ24CA TVS, and a 0.5A resettable fuse for PPTC. The specific implementation steps are as follows: 1. Triggering Steps Connect the DC+ and DC- lines of the passive energy storage and control circuit to a DC 24V power supply, and connect the X1 / X2 lines of the output interface to the DC 24V bistable solenoid valve coil. The valve core switching is triggered only by turning on and off the DC 24V power supply. Turning on the power supply is the first trigger action, and turning off the power supply is the second trigger action.

[0156] 2. Execution Steps (1) When the power is turned on, the reverse connection protection circuit of the MOS transistor in the power interface unit is activated, and the PPTC overcurrent protection and TVS overvoltage protection are in working state; the voltage monitoring module of the control logic unit detects that the power is turned on and transmits the signal to the MCU, and the MCU control circuit enters the energy storage mode. Since there is no voltage conversion unit, the DC 24 V power supply directly charges the capacitor of the energy storage unit through the power interface unit, and the charging circuit is connected in series with a unidirectional conductive diode; the capacitance is calculated according to the formula C≥2E. min / U² is calculated, where E min The minimum energy required for the spool switching of this DC 24 V bistable solenoid valve is given by U, which is 24 V. The final capacitance is determined by combining this with a safety margin.

[0157] In this embodiment, for a bistable solenoid valve with a rated voltage of 24 V, the minimum energy E required for its valve core to complete one reliable switching was tested. min Approximately 0.1 J, according to the formula C≥2E min Based on / U² calculations, the theoretical minimum capacitance is approximately 347 μF. Considering circuit losses, the aging tolerance of the energy storage capacitor, and long-term reliability, this embodiment introduces a safety margin, preferably using an electrolytic capacitor with a nominal capacity of 1000 μF, which is approximately 2.9 times the theoretically calculated value. The energy storage capacitor is a low-leakage capacitor with a leakage current not exceeding 25 μA, ensuring sufficient stored energy to overcome non-ideal factors and guarantee high reliability of the solenoid valve core operation. Since the leakage power consumption meets near-zero power consumption requirements, this embodiment does not require additional pulse power compensation control.

[0158] (2) During the charging process of the energy storage capacitor, the MCU outputs a “10” control signal to the H-bridge circuit of the polarity switching output unit, Q01 and Q04 are turned on, generating a DC 24 V drive current pulse in the first direction. The pulse width is set to 50ms, driving the valve core to switch to the first steady state position (valve open).

[0159] The pulse width setting is specified in the product manual for this type of valve as 30ms. During verification testing, this valve operated perfectly normally in the test environment with a pulse setting of 20ms. Therefore, based on a safety margin, this example uses 50ms. The data port of the control logic unit in this embodiment can be flexibly set to shorter or longer pulse parameters (e.g., 10ms to 10 seconds).

[0160] (3) After the pulse output is completed, the MCU will switch the control signal to "00", and all four switching devices of the H-bridge circuit will be turned off, entering the zero power consumption state.

[0161] (4) When the DC 24 V power supply is disconnected, the voltage monitoring module detects the power disconnection and transmits a signal to the MCU. The MCU immediately outputs a “01” control signal to the H-bridge circuit, Q03 and Q02 are turned on, the energy storage capacitor releases electrical energy, and generates a DC 24 V drive current pulse in the second direction. The pulse width is set to 50ms, which drives the valve core to switch to the second steady-state position (valve closed).

[0162] Power-off pulse explanation: Given that the current of ultra-low-power MCUs in standby / run mode is extremely low (microamp level), and the current approaches zero when GPIO pins drive internal logic gate loads, the energy required for the control loop is minimal. Therefore, by setting an independent decoupling / energy storage capacitor (e.g., 0.1µF~100µF) at the MCU's VCC terminal, the MCU supply voltage can be maintained above the reset threshold for a time T_ after the external power supply is disconnected. The discharge is much greater than T_pulse. (Where T_pulse is the reverse drive current) The duration of the flow pulse, T _discharge is the critical time when the control logic unit loses its ability to function due to power disconnection.

[0163] (5) After the pulse output is completed, the MCU switches the control signal to "00" again, and the H-bridge circuit returns to the zero power consumption state.

[0164] 3. Maintenance steps After the first directional pulse output is completed, the valve core maintains the valve in the first stable open position through the bistable magnetic latching structure, and the solenoid valve coil is completely de-energized; at the same time, the passive energy storage and control circuit enters a silent maintenance state, and the MCU switches to power-down mode. The power consumption of each unit is as follows: power interface unit 1.5mW, energy storage unit 0.6mW, control logic unit 0.024mW, polarity switching output unit 0mW, and the total power consumption of the entire circuit is 2.124mW < 5mW, achieving zero power consumption maintenance; when the power is disconnected, triggering the valve core to switch to the second stable position, the valve core maintains the valve in the closed state, and the circuit also enters the above-mentioned zero power consumption maintenance state.

[0165] In this embodiment, after power is turned on, the MCU confirms power stability and then starts charging the capacitor of the energy storage unit, completing the charging and energy storage according to a preset algorithm. Simultaneously, it outputs a "10" signal through the two GPIO control pins CT1 and CT2. The polarity switching output unit receives this signal and controls Q01 / Q04 of the H-bridge circuit to conduct, with the output duration precisely matched to 50ms to ensure safe and reliable valve core switching. After the pulse stops, the MCU outputs a "00" signal within 5μs, cutting off the power supply to the solenoid valve coil. At the same time, the passive energy storage and control circuit enters a silent maintenance state, and the MCU switches to power-down mode.

[0166] When the control logic unit detects a power outage, the MCU returns to the operating mode and outputs a precise 50ms "01" signal through the two GPIO control pins CT1 and CT2 within microseconds. This triggers the energy storage capacitor to discharge and controls the conduction of Q03 / Q02 in the H-bridge circuit. The timing error is ≤5μs, ensuring reliable valve core switching.

[0167] The entire process relies on the creative and precise matching of energy supply, timing control, and logic control, rather than a simple stacking of components.

[0168] In this embodiment, to prevent jitter interference during the switching on and off of external power, the control logic unit is equipped with a power state debouncing mechanism. Specifically, the triggering step further includes: setting a debouncing time threshold T_ bounce; detect external power supply The duration of the disconnection is Δt; only when Δt > T_bounce is it considered a valid "power-off trigger command" and a reverse response is generated. Driven pulse; if Δt≤T _bounce is considered a momentary power interruption, and the control logic unit maintains its original state without generating a drive pulse.

[0169] Furthermore, when the control logic unit determines that the duration of the external power disconnection Δt > T_bounce, it triggers the power-off pulse generation mechanism: the control logic unit has an independent energy storage / decoupling capacitor arranged between the MCU's VCC and ground (this energy must meet the timing constraint condition that T_discharge > T_pulse), and immediately generates a short reverse drive pulse (e.g., T_pulse = 50ms, where T_pulse is the pulse duration). The polarity of this pulse is opposite to the steady-state polarity currently held by the solenoid valve. The reverse drive pulse is applied to the bistable solenoid valve through the H-bridge of the polarity switching output unit, driving the solenoid valve to switch to another steady-state position. After the pulse ends, the control logic unit completes the state switch and enters the low-power maintenance mode. Even if the stored energy is quickly depleted, the solenoid valve will still continue to maintain the new steady-state position.

[0170] In this embodiment, the fault diagnosis logic described herein utilizes an ADC module built into the MCU that monitors the energy storage capacitor voltage in real time via a dynamic sampling circuit. This dynamic sampling circuit consists of an NPN transistor (or NMOS transistor) and a high-resistance resistor voltage divider network. In standby mode, the transistor is off, and the voltage divider network is disconnected from the MCU ADC pin, thus eliminating the static power consumption of the voltage divider resistor. When the fault diagnosis drive pulse window (50ms) is entered, the MCU outputs a high level through a GPIO pin, momentarily turning on the transistor and sending the high-voltage signal, after voltage division, to the ADC pin for sampling.

[0171] If a voltage drop ΔV_ is detected within the drive pulse window (50ms) actual is less than the preset threshold V_ If the threshold (e.g., 1V, corresponding to insufficient energy to overcome magnetoresistance) is met and the GPIO detects a valid drive signal, then it is determined to be... Open circuit fault. For example, when the solenoid valve coil is disconnected, the capacitor voltage hardly changes during the pulse (e.g., ΔV). When the actual value approaches 0, the MCU will then output a fault alarm signal via the optocoupler or light up the LED display alarm on this control circuit.

[0172] In this embodiment, the passive energy storage and control circuit is integrated into a junction box conforming to the DIN43650 interface standard. The two downstream lines are connected to the male metal spring of the solenoid valve coil via a female metal spring. The entire system has no external devices, and the control logic is completely consistent with that of a DC 24 V direct-acting monostable solenoid valve, achieving zero-power control of a DC 24 V bistable solenoid valve. It can also be referred to as a DC 24 V zero-power bistable normally closed / normally open solenoid valve. Of course, in other embodiments, the size or interface of the junction box can be adaptively adjusted according to the actual component layout of the passive energy storage and control circuit, which does not depart from the essence of the integrated design of this invention.

[0173] In this embodiment, the passive energy storage and control circuit is integrated into the standard solenoid valve junction box, forming a bistable solenoid valve zero-power controller. Its two-wire input terminals are connected to a DC 24 V power supply, and its two-wire output terminals are embedded with the solenoid valve coil metal male spring through a metal female spring. The whole product can directly replace the junction box of the traditional solenoid valve without additional modification to the installation structure, making it convenient to use.

[0174] Example 5: A DC5V power supply drives a DC24V bistable solenoid valve (with boost mode voltage conversion unit). This embodiment uses a DC 5V power supply as the external power source to drive a single-coil bistable solenoid valve with a rated operating voltage of DC 24V. The passive energy storage and control circuit is equipped with a voltage conversion unit and operates in boost mode. The specific implementation steps are as follows: 1. Triggering steps: Connect the two upstream lines of the passive energy storage and control circuit to a DC5V power supply, and connect the two downstream lines to a DC24V bistable solenoid valve coil. The valve core is switched by switching the DC5V power supply on and off. When the power supply is on, the valve core is triggered to the first steady-state position, and when the power supply is off, the valve core is triggered to the second steady-state position.

[0175] 2. Execution steps: (1) When the power is turned on, the power interface unit completes the protection against reverse connection, overvoltage and overcurrent. The voltage monitoring module of the control logic unit detects that the power is turned on and transmits it to the MCU. The MCU control circuit enters the energy storage mode and at the same time controls the DC / DC boost chip of the voltage conversion unit to start and boost DC5V to DC24V. (2) The boosted DC24V voltage is used to charge the low leakage capacitor of the energy storage unit. The charging circuit is connected in series with a unidirectional conductive diode. The capacity of the energy storage capacitor is calculated according to the formula C≥2Emin / U² (U=24V). A safety margin of 1.5 times is introduced. Compared with the scheme without boost unit, the energy storage capacitor capacity requirement of this embodiment is lower. In this embodiment, for a bistable solenoid valve with a rated voltage of 24V, the minimum energy Emin required for the valve core to complete one reliable switching is approximately 0.1 Joules (J). Based on the formula C≥2E / U², assuming a drive voltage of 5V, the calculated energy storage capacitor capacity is 8000μF. The theoretical minimum capacitance using a boosted DC 24V rated voltage is approximately 347μF. This embodiment introduces a 1.5 times safety margin, selecting a nominal 680μF energy storage capacitor with a leakage current of 10μA.

[0176] (3) After the energy storage capacitor is fully charged, the MCU outputs a “10” control signal to the H-bridge circuit to generate a DC24V drive current pulse in the first direction. The pulse width is set to 100ms to drive the valve core to switch to the first steady state position (valve open). After the pulse is completed, the control signal switches to “00”. (4) When the DC5V power supply is disconnected, the voltage monitoring module detects the power disconnection and transmits it to the MCU. The MCU outputs a “01” control signal to the H-bridge circuit, the energy storage capacitor releases energy, and generates a DC24V drive current pulse in the second direction. The pulse width is set to 100ms, which drives the valve core to switch to the second steady-state position (valve closed). After the pulse is completed, the control signal switches to “00”.

[0177] 3. Maintenance steps: After the valve core is switched, the position is maintained by the bistable magnetic holding structure, and the solenoid valve coil is de-energized. The passive energy storage and control circuit enters the silent maintenance state, the MCU switches to power-down mode, and the voltage conversion unit enters the silent state. The power consumption of each unit is as follows: power interface unit 1.2mW, energy storage unit 0.24mW, control logic unit 0.024mW, polarity switching output unit 0mW, voltage conversion unit 0.3mW. The total power consumption of the entire circuit is 1.764mW < 5mW, achieving zero power consumption maintenance.

[0178] This embodiment realizes the driving of a high-voltage DC24V bistable solenoid valve by an ultra-low DC voltage of DC5V without changing the solenoid valve coil specifications. The control logic is simple and it is suitable for application scenarios powered by low-voltage power supplies such as microcontrollers and embedded devices.

[0179] Example 6: AC220V power supply drives DC12V bistable solenoid valve (with buck mode voltage conversion unit) This embodiment uses an AC220V power supply as the external power source to drive a single-coil bistable solenoid valve with a rated operating voltage of DC12V. The power interface unit of the passive energy storage and control circuit is equipped with a rectifier bridge and a filter capacitor, and a voltage conversion unit is configured and operates in buck mode. The power input of the control logic unit is connected to the output of the voltage conversion unit. The specific implementation steps are as follows: 1. Triggering steps: Connect the two upstream lines of the passive energy storage and control circuit to an AC220V AC power supply, and connect the two downstream lines to a DC12V bistable solenoid valve coil; the valve core is switched by the single switching on and off of the AC220V power supply. When the power is on, the valve core is triggered to the first steady-state position, and when the power is off, the valve core is triggered to the second steady-state position.

[0180] 2. Execution steps: (1) When the power is turned on, AC220V AC power is converted into DC311V DC power through the rectifier bridge of the power interface unit. TVS overvoltage protection and PPTC overcurrent protection are activated. At the same time, the DC / DC step-down chip of the voltage conversion unit is activated. The DC / DC step-down chip adopts a non-isolated step-down circuit with a wide input voltage range and has low static current characteristics. It can stably convert the input DC voltage into the working voltage required by the system, that is, step down DC311V to DC12V. At the same time, it ensures that the power consumption is automatically controlled at an extremely low level during the maintenance phase of ultra-light load. The voltage monitoring module of the control logic unit detects the power is turned on and transmits it to the MCU. The MCU control circuit enters the energy storage mode.

[0181] (2) The DC12V voltage after step-down is used to charge the low leakage capacitor of the energy storage unit. The charging circuit is connected in series with a unidirectional conductive diode. The capacity of the energy storage capacitor is calculated according to the formula C≥2Emin / U² (U=12V). A safety margin of 5 times is introduced to ensure the driving reliability under AC power input. In this embodiment, for a bistable solenoid valve with a rated voltage of DC12V, the minimum energy Emin required for the valve core to complete one reliable switching is approximately 0.045 joules (J). Based on the formula C≥2E / U², the theoretical minimum capacitance is approximately 625μF. This embodiment introduces a 2.5 times safety margin, selecting a storage capacitor with a nominal value of 1500μF and a leakage current of 10μA.

[0182] (3) After the energy storage capacitor is fully charged, the MCU outputs a “10” control signal to the H-bridge circuit to generate a DC12V drive current pulse in the first direction. The pulse width is set to 300ms to drive the valve core to switch to the first steady state position (valve open). After the pulse is completed, the control signal switches to “00”. (4) When the AC220V power supply is disconnected, the voltage monitoring module detects the power disconnection and transmits it to the MCU. The MCU outputs a “01” control signal to the H-bridge circuit, the energy storage capacitor releases energy, the voltage conversion unit maintains the step-down state, and generates a DC12V drive current pulse in the second direction. The pulse width is set to 300ms, which drives the valve core to switch to the second steady-state position (valve closed). After the pulse is completed, the control signal switches to “00”.

[0183] 3. Maintenance steps: After the valve core switching is completed, the position is maintained by a bistable magnetic holding structure, and the solenoid valve coil is de-energized. This puts the passive energy storage and control circuit in an ultra-light load state, which causes the voltage conversion unit to automatically enter a milliwatt-level standby state. Actual operating condition tests show that under AC220V, AC110V, and AC24V input power conditions, the overall static power consumption of the passive energy storage and control circuit during the maintenance step is 78mW, 46mW, and 39.2mW, respectively. The power interface unit and voltage conversion unit contribute approximately 75mW (at AC220V), with the remaining power consumption mainly originating from the small leakage current of the energy storage capacitor, the nA-level static current of the control chip, and the extremely low leakage current of the H-bridge output stage. All test values ​​meet the near-zero power consumption maintenance requirements of this invention, and the overall power consumption decreases as the input voltage decreases. This embodiment demonstrates that by selecting low-power components, excellent performance of less than 80mW overall maintenance power consumption under AC input can be achieved.

[0184] This embodiment realizes the direct drive of a conventional DC12V bistable solenoid valve by a high-voltage AC power supply of AC220V without the need for additional AC-DC power conversion equipment. It is suitable for applications powered by residential mains electricity. The control logic is the same as that of a common direct-acting solenoid valve, making it easy to use.

[0185] Example 7: Zero-power control of a high leakage capacitance energy storage unit (pulse power compensation + hardware hysteresis) This embodiment uses a DC 24V power supply to drive a DC 24V bistable solenoid valve. The electrical connection of the energy storage unit in this embodiment is as follows: Figure 9 As shown. The dashed-dot box indicates optional design options; in this embodiment, all options are selected. Simultaneously, the Vp power-up pulse output is electrically connected to the Vc switch control input.

[0186] The specific implementation steps are as follows: 1. Triggering Steps Connect the two upstream lines of the passive energy storage and control circuit to a DC 24 V power supply, and the two downstream lines to a DC 24 V bistable solenoid valve coil. The circuit does not include a voltage conversion unit. The capacitance is calculated using the formula C≥2Emin / U² (U=24 V), and with a safety margin of 3, the energy storage capacitor Cx is determined to be 1000 μF.

[0187] When the energy storage capacitor Cx has a large leakage current (e.g., 200 μA) due to device aging or quality differences, if the capacitor voltage is maintained by the traditional continuous power supply method, its static power consumption will be as high as 4.8 mW, resulting in significant energy waste.

[0188] To address the aforementioned issues, this embodiment combines "pulse-based power supply + hardware hysteresis" control technology with electronic switch control technology. Specifically, it selects a pulse-based power supply + hardware hysteresis module 302 and an electronic switch module 303, and electrically connects the Vp power supply pulse output to the Vc switch control input. The valve core switching is triggered by a single on / off cycle of the DC 24V power supply. When the power is on, the valve core is driven to the first steady-state position; when the power is off, the valve core is driven to the second steady-state position.

[0189] 2. Execution Steps When the power is turned on, the voltage of the energy storage capacitor Cx is 0 in the initial state. The output Vp charging pulse makes the electronic switch module 303 turn on, completing the charging of the energy storage capacitor Cx. The MCU control circuit generates a first direction drive current pulse to drive the valve core to the first steady state position.

[0190] When the power is disconnected, the MCU controls the energy storage capacitor Cx to discharge and generate a second-direction drive current pulse, which drives the valve core to the second steady-state position.

[0191] 3. Maintenance steps After the valve core switching is completed, the solenoid valve coil is de-energized. Due to leakage, the voltage at the positive terminal of the energy storage capacitor Cx drops, triggering the pulse power replenishment + hardware hysteresis module to perform pulse power replenishment 302. The pulse width of Vp power replenishment is set to 10 ms. After power replenishment is completed, the circuit immediately returns to the silent state. The hardware hysteresis avoids excessive power consumption caused by frequent power replenishment. The overall circuit achieves zero power consumption maintenance by adding 1.5 mW of pulse power replenishment power to the static power consumption of each unit.

[0192] Specifically, a 4V voltage hysteresis window is set (e.g., dynamically adjusted within the 20V to 24V range), and a hardware comparator monitors the capacitor voltage status in real time. Theoretical calculations and experimental verification show that the charging cycle is approximately 20 seconds, with each charging pulse width set to an adjustable range between 5ms and 20ms; preferably, this embodiment sets the pulse width to 10ms to balance charging efficiency and device stress.

[0193] Even under the most unfavorable operating condition with a capacitor leakage current as high as 200 μA, the average additional power consumption introduced by the compensation pulse is less than 50 μW (microwatt level) due to its extremely low duty cycle (less than 0.1%). At this point, the total system sustaining power consumption is mainly determined by the static power consumption of the low-power comparator circuit (e.g., 1.5 mW). Comprehensive calculations show that the total power consumption in this embodiment can be controlled at a near-zero power level (e.g., around 1.5 mW), representing a power reduction of over 68% compared to the traditional 4.8 mW sustaining scheme.

[0194] It should be noted that in this embodiment, when the voltage of the energy storage capacitor drops to 20 V due to leakage or environmental factors, it still stores approximately 0.2 joules of energy. This energy value is much greater than the minimum energy required for the bistable solenoid valve to complete the valve core switching (e.g., 0.01~0.1 joules), thereby ensuring that the energy storage capacitor can provide reliable drive protection across the entire voltage range.

[0195] This technical solution not only ensures the reliability of the solenoid valve's driving energy but also avoids heat loss caused by continuous current through a pulsed power replenishment mechanism, achieving extremely high energy utilization efficiency. This embodiment verifies a zero-power control scheme in high leakage capacitance scenarios, improves the adaptability of this invention to capacitors of different specifications, and reduces the material cost of the energy storage unit.

[0196] It should be noted that the electronic switch module 303 shown in this embodiment and in Figure 9 is optional; when a voltage conversion unit is present and the unit has an EN pin, the Vp compensation pulse output can be directly electrically connected to the EN pin. In this case, the electronic switch module 303 can be omitted. This can further reduce the static power consumption of the voltage conversion unit and simultaneously reduce the power consumption of the entire controller during the maintenance step.

[0197] The core innovation of this embodiment lies in breaking through the existing understanding that "low leakage capacitance is a prerequisite for zero power consumption." Through the synergistic design of "pulse compensation + hardware hysteresis," a low-cost electrolytic capacitor with a leakage current as high as 200 μA can still achieve a maintenance power consumption of ≤1.524 mW. This solution requires extensive experimentation to determine key parameters such as the hysteresis window (20 V~24 V, based on a capacitor voltage drop rate of 0.2 V / s under a leakage current of 200 μA), the compensation pulse width (10 ms), and the compensation cycle (20 seconds) to ensure that the energy stored in the capacitor always meets the valve core switching requirements, while avoiding additional power consumption during the compensation process. There are no general formulas to apply to these parameter designs; they rely entirely on the applicant's creative labor.

[0198] Example 8: Multi-channel integrated mode (DC24V driving 4 DC24V bistable solenoid valves) This embodiment uses a DC 24V power supply as the external power source to drive four single-coil bistable solenoid valves with a rated operating voltage of DC 24V. The passive energy storage and control circuit is configured as a 4-channel integrated structure. Core component selection: The MCU is an STM32L071KBU6 (multi-GPIO pin type); the H-bridge switching device is a power drive module composed of four sets of all-N-channel MOSFETs (each module uses four AO3400N-channel MOSFETs as the core switching device, with a bootstrap drive circuit. The bootstrap drive circuit used in this invention is a passive auxiliary circuit, working only during the moment of action, and its static power consumption is negligible, not affecting the overall low-power design goal). The specific implementation steps are as follows: 1. Triggering steps: Connect the two input lines of the passive energy storage and control circuit to a DC24V power supply, and connect the four output interfaces to the coils of four DC24V bistable solenoid valves respectively. The switching of all solenoid valves can be triggered synchronously by switching the DC24V power supply on and off, or the switching of a single or partial solenoid valve can be triggered by sending a command (including the channel number) through the UART interface.

[0199] 2. Execution steps: (1) When the power is turned on, the reverse connection, overvoltage and overcurrent protection of the power interface unit is activated. The voltage monitoring module of the control logic unit detects that the power is turned on and transmits it to the MCU. The MCU control circuit enters the energy storage mode. The DC24V power supply directly charges the 4700μF energy storage capacitor (the capacitor capacity is calculated based on the minimum total energy of the four solenoid valves switching synchronously, E_total = 4 × 0.1J = 0.4J, C ≥ 2 × 0.4J / (24V)² ≈ 1389μF, and 4700μF is selected with a safety margin of 3.5 times). (2) During the charging process of the energy storage capacitor, the MCU outputs a “10” control signal to the four polarity switching output units, and the diagonal switching devices of the four H-bridges are turned on at the same time, generating a DC24V drive current pulse in the first direction (pulse width 500ms), which drives the four solenoid valves to switch to the first steady state position (valve open) synchronously. (3) After the pulse output is completed, the MCU will switch the control signal to "00", and all H-bridge switching devices will be turned off, entering the zero power consumption state; (4) When the DC24V power supply is disconnected, the MCU detects that the power supply is disconnected and outputs "01" control signals to the four polarity switching output units. The energy storage capacitor releases electrical energy and generates a second-direction DC24V drive current pulse (pulse width 500ms), which drives the four solenoid valves to switch synchronously to the second steady-state position (valve closed). (5) If the instruction "Channel 2 Close" is sent through UART, the MCU will only output "01" control signal to the polarity switching output unit of the second channel, while the other channels will remain in the "00" state, thus realizing the independent control of a single solenoid valve.

[0200] Furthermore, for the multi-channel integrated mode, the control logic unit is configured as a time-division drive mode: when a 'full channel switching' command is received (or an external power supply is detected to be disconnected), the MCU controls the drive pulses of each channel to be output sequentially at a preset time interval ΔT, rather than being output simultaneously.

[0201] Where △T > T_action, and T_action is the time required for a single bistable solenoid valve to complete the mechanical switching.

[0202] For example, in 4-channel mode, channel 1 operates at time t0, channel 2 operates at time t0+ΔT, and so on. By time-division multiplexing the energy of the energy storage capacitor, the peak current requirement of the energy storage capacitor can be reduced to 1 / n of the peak current of a single channel (where n is the number of channels), thereby significantly reducing the size and cost of the energy storage capacitor.

[0203] 3. Maintenance steps: After the solenoid valve switches, the valve core maintains its position through the bistable magnetic holding structure, and the coil is completely de-energized; the passive energy storage and control circuit enters the silent maintenance state, the MCU switches to power-down mode, and the total power consumption of the entire circuit is 3.8mW < 5mW, achieving zero power consumption maintenance.

[0204] This embodiment achieves centralized control of four H-bridge drive circuits through time-division multiplexing of GPIO pins by the MCU, with a channel switching delay of ≤100ns, effectively improving the control efficiency and response speed of the multi-channel valve group. Simultaneously, the energy storage capacitor capacity is designed according to the total energy required for synchronous switching of the four channels (C=4700μF), satisfying the energy supply required for synchronous switching while avoiding volume redundancy due to excessive capacity. This achieves a balanced optimization between energy supply and hardware integration, representing a creative optimization of the multi-module combination structure.

[0205] This embodiment can further expand the local button control function by adding a local button input unit 509 to the control logic unit 500, which includes four physical buttons (K1~K4), corresponding to four output channels (CH0~CH3). When button K1 is pressed, the control logic unit only outputs a drive pulse to channel CH0, realizing independent control of a single channel; when buttons K1 and K2 are pressed simultaneously, channels CH0 and CH1 can be triggered synchronously, realizing multi-channel group control. This design does not rely on a communication bus or external controller and can directly complete single-valve / multi-valve debugging on-site, further improving the ease of use and scenario adaptability of the product.

[0206] This embodiment ultimately achieves centralized control of multiple solenoid valves with a single power supply and a single controller. It eliminates the need for an external pulse transmitter, simplifies the wiring structure (requiring only one power input line), and can be widely applied to integrated control scenarios of multiple valves within equipment, such as multi-channel valve group control in smart homes and centralized control of valve groups in small fluid equipment. The overall solution is simple in structure, flexible in control, highly reliable, and highly integrated, demonstrating significant technical practicality and innovation.

[0207] Example 9: Bus networking mode (RS485 bus control of 8 bistable solenoid valves) This embodiment uses 8 sets of passive energy storage and control circuits (corresponding to 8 DC24V bistable solenoid valves). Each set is equipped with a general data interface 511, which is set as an RS485 standard interface. A control network is formed through the RS485 bus. One STM32F103 is configured as the master controller, and each slave controller (passive energy storage and control circuit) is assigned an independent address (number 1~8). The specific implementation steps are as follows: System setup: The RS485 interfaces of 8 slave controllers are connected to the RS485 interface of the master controller. The input interface of each slave controller is connected to a DC24V power supply, and the output interface is connected to 8 bistable solenoid valve coils respectively. The master controller issues control commands through the Modbus protocol.

[0208] Triggering and execution steps: (1) The main controller sends the instruction “address 1 + open + pulse width 600ms”. After receiving the instruction from the controller, No.1 controls the energy storage capacitor to charge and generates the first direction drive current pulse to drive No.1 solenoid valve to open. (2) The main controller sends the instruction "all addresses + off + pulse width 500ms", and the 8 slave controllers receive the instruction synchronously, release the energy of the energy storage capacitor to generate the second direction drive current pulse, and drive all solenoid valves to close; (3) The main controller sends the instruction “address 3-6 + open + pulse width 700ms”, and slave controllers 3-6 execute synchronously to drive the corresponding solenoid valves to open, while solenoid valves 1-2 and 7-8 remain in their original state.

[0209] Maintenance procedure: After each slave controller completes its pulse output, it enters a silent maintenance state, with overall power consumption of <5mW under DC24V input; the master controller can query the operating status of each slave controller in real time (such as energy storage capacitor voltage, current steady state of solenoid valve) through bus commands to achieve preventive maintenance.

[0210] This embodiment realizes unified bus control of distributed solenoid valves, which is suitable for multi-valve group management in large systems (such as workshop production lines and smart water pipe networks). It features simple wiring, convenient maintenance, support for remote parameter configuration, and strong scalability.

[0211] The above embodiments are only typical application scenarios of the present invention. The control method of the present invention can also be adapted to various external power supplies such as DC3.3V, DC24V, AC24V, and AC110V to drive bistable solenoid valves of different specifications such as DC12V and DC24V. It is only necessary to select a voltage conversion unit and adjust its working mode according to the matching relationship between the power supply voltage and the solenoid valve coil voltage, and adjust the energy storage capacitor capacity and drive current pulse parameters according to the solenoid valve specifications. All of these can achieve the near-zero power consumption control effect of the present invention.

[0212] The scope of protection of this invention is defined by the claims and is not limited to the specific embodiments described above.

Claims

1. A near-zero power consumption control method for a bistable solenoid valve, characterized in that, Includes the following steps: Triggering steps: The valve core switching command is sent to the bistable solenoid valve by a single on / off action of the external AC or DC power supply, without the need for additional control signal lines; Execution steps: Obtain and store electrical energy from an external power source through a passive energy storage and control circuit; generate a drive current pulse in the first or second direction according to the triggering steps; drive the valve core to switch to the corresponding steady-state position. Maintenance steps: After the drive current pulse ends, the bistable solenoid valve maintains the valve core position by relying on the permanent magnet, and the solenoid valve coil is de-energized; at the same time, the passive energy storage and control circuit enters a silent low power consumption state, and the overall power consumption drops to near zero. In the execution steps, a first direction drive pulse is generated when the external power supply is turned on, and a second direction drive pulse is generated when the external power supply is turned off.

2. The near-zero power consumption control method for a bistable solenoid valve according to claim 1, characterized in that, In the maintenance step: when the input external power supply is DC3V~DC40V DC power supply, the overall power consumption is less than 5mW; when the input external power supply is AC24V~AC220V AC power supply, the overall power consumption is less than 80mW.

3. The near-zero power consumption control method for a bistable solenoid valve according to claim 1, characterized in that, The step of generating a second-direction drive current pulse when the external power supply is disconnected relies on the energy isolation and coordination between the filter capacitor and the energy storage capacitor at the power supply end of the pulse generator in the control logic unit; the method includes: using the energy stored in the filter capacitor to maintain the transient operation of the pulse generator after the power supply is disconnected, so that it outputs a control signal within a critical time before losing its working ability; at the same time, using the electrical energy stored in the energy storage capacitor as a drive source, outputting a reverse drive current pulse to the bistable solenoid valve through a diode isolation circuit; Wherein, the duration T_ of the reverse drive current pulse pulse is configured Less than the critical time T _discharge, to ensure that the valve core switching action is completed using the energy of the energy storage capacitor before the pulse generator is reset.

4. The near-zero power consumption control method for a bistable solenoid valve according to claim 1, characterized in that, The control logic unit includes a pure hardware logic circuit, which consists of a power detection module, a logic control module, and a pulse timing module. Signal transmission is achieved through hard-wired logic. The signal transmission delay is on the nanosecond level, enabling the solenoid valve to respond to commands at the physical limit speed and unaffected by software malfunctions.

5. The near-zero power consumption control method for a bistable solenoid valve according to claim 1, characterized in that, The triggering step also includes a power state debouncing mechanism: through hardware filtering or digital logic judgment, only when the duration Δt of the external power disconnection is greater than the preset debouncing time threshold T_bounce is it determined to be a valid "power-off trigger command"; if Δt≤T_bounce, it is regarded as power interference or momentary interruption, and the control logic unit maintains the original state and does not generate a drive pulse; wherein, the debouncing time threshold T_bounce is configured to be an integer multiple greater than the industrial power grid cycle to avoid false triggering caused by industrial power grid fluctuations.

6. A near-zero power consumption controller for a bistable solenoid valve, characterized in that, It includes a passive energy storage and control circuit; the passive energy storage and control circuit is configured to: when the external power supply is cut off, it can rely entirely on the energy stored in its internal capacitor to autonomously complete a state switching drive of the bistable solenoid valve; the passive energy storage and control circuit includes a power interface unit, an optional voltage conversion unit, an energy storage unit, a polarity switching output unit, and a control logic unit electrically connected to each unit; The power interface unit connects to an external AC / DC power supply and integrates reverse connection protection, overvoltage protection, and overcurrent protection functions. The voltage conversion unit is connected between the power interface unit and the energy storage unit, and is used to convert the input voltage into the working voltage that is compatible with the solenoid valve coil, or to pass through when no conversion is required. The energy storage unit is an electrical energy storage carrier used to provide energy for the driving current pulse; The polarity switching output unit is connected between the energy storage unit and the bistable solenoid valve coil, and is used to switch the polarity of the drive current in response to the control signal. The control logic unit includes a power status detection module and a pulse drive control module; The power status detection module is used to monitor the on / off status of the external power supply in real time and generate corresponding logic level signals. The pulse drive control module is coupled to the power status detection module and is used to generate a polarity switching control signal based on the logic level signal, and control the energy storage unit to release drive energy to the solenoid valve coil.

7. The near-zero power consumption controller according to claim 6, characterized in that, The control logic unit includes a wide-input ultra-low static power regulator chip or a DC / DC buck chip, a voltage monitoring module, and a microcontroller (MCU). The voltage regulator chip or DC / DC buck chip converts the external input voltage into the standard operating voltage of the MCU. The voltage monitoring module is used to detect the power supply status in real time and output a level signal to the MCU. The MCU can switch to power-down mode or sleep mode to achieve ultra-low power operation, and can receive external configuration commands through the communication interface to adjust the pulse width and peak current parameters of the drive current pulse, adapting to bistable solenoid valves of different specifications.

8. The near-zero power consumption controller according to claim 6, characterized in that, The control logic unit includes a pure hardware logic circuit, which includes a power detection module, a logic control module, a pulse timing module, and an energy maintenance module. The power detection module is used to monitor the on / off status of the external power supply in real time and output a trigger level. The logic control module is used to generate state switching logic based on the trigger level; The pulse timing module is used to generate drive pulses of fixed width; The energy maintenance module includes an isolation diode and an energy storage capacitor, which are used to provide a maintenance power supply for the pure hardware logic circuit at the moment of power disconnection, ensuring the reliable generation of the reverse drive pulse.

9. The near-zero power consumption controller according to claim 6, characterized in that, The polarity switching output unit includes an H-bridge circuit, which includes a switching device and a freewheeling diode. The control logic unit outputs complementary control signals to control the diagonal switching devices of the H-bridge circuit to conduct in order to switch the current direction, and to prevent the switching devices from being directly short-circuited through software programming or hardware logic; the freewheeling diode is used to absorb the reverse electromotive force of the coil and protect the switching devices.

10. The near-zero power consumption controller according to claim 6, characterized in that, The controller adopts a two-wire input and two-wire output wiring structure, and has standardized input terminals and output terminals; the circuit can be integrated into the solenoid valve junction box or the solenoid valve body, or independently packaged as an external module.

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