117 results about "Proportional valve" patented technology

The utility model relates to proportional valve technical field provides a kind of modular proportional valve of split type, including valve body, the valve body upper end is fixedly connected with intermediate valve body, the intermediate valve body upper end is fixedly connected with connecting seat, the connecting seat outside is fixedly connected with clamping block, the connecting seat upper end is provided with control part, the control part outside is provided with clamping assembly;The clamping assembly includes the metal sheet fixedly installed in the control part both sides, the metal sheet lower end is equipped with clamping groove, the utility model has the beneficial effects that: through the corresponding cooperation of clamping block and clamping groove, and the guiding slope surface of metal sheet inclined section, it can be installed by inserting, pulling transmission rod, it can be rotated by transmission frame to make the elastic deformation of extruding strip synchronous extrusion metal sheet, make clamping groove and clamping block separate, and operator can realize unlocking by single hand pulling transmission rod, realize toolless quick disassembly, simple structure, convenient to use.

The utility model discloses a kind of selectable valve core reset device, access oil pressure control system and emergency shutdown valve hydraulic control system, and is equipped with three oil paths: the first two access oil tank of oil pressure control system, the third access its oil pressure accumulator, dry road is equipped with electric valve and has multiple branch lines afterwards.Device contains switch control valve, auxiliary booster mechanism, hydraulic feedback mechanism, double filter, digital valve, proportional valve, proportional digital switching valve, auxiliary switching valve, two hydraulic control reversing valves and two travel switches, etc., and is connected into complete control and execution system by pipeline.It can be switched digital valve and proportional valve control mode by proportional digital switching valve, adapt to different working conditions;With hydraulic control reversing valve and travel switch cooperation, realize oil path accurate control and valve core reset monitoring feedback, improve accuracy;It is also equipped with main matching position sensor, manual valve etc., enhance system stability and controllability, can guarantee valve core reset reliable under complex working condition, improve oil pressure pump oil conveying system overall efficiency and reliability.

The application relates to the technical field of mechanical control, in particular to a power matching control method and system applied to engineering machinery. The method comprises the following steps: acquiring a real-time engine speed corresponding to a current control time period of the engineering machinery; acquiring a current working condition parameter, performing working condition recognition analysis on the current working condition parameter according to a preset full-working-condition database, and obtaining a target real-time working condition; determining an initial control current according to the real-time engine speed and the target real-time working condition; performing a dynamic closed-loop correction operation on the initial control current to obtain a target control current; and controlling a proportional valve controller of the engineering machinery according to the target control current to perform power matching on the engineering machinery in the current control time period. Through the construction of the database covering full working conditions, the power matching can comprehensively adapt to multi-working-condition changes, the accuracy of the power matching is guaranteed, and the accuracy of the power matching is further improved through the dynamic closed-loop correction for adjusting the control current.

The application relates to the technical field of piezoelectric control valves, in particular to a pressure proportional valve based on a bidirectional bending piezoelectric diaphragm, which comprises a valve body internally provided with a mounting cavity, a gas supply port, a working port and an exhaust port being arranged on the valve body and communicated with the mounting cavity; the bidirectional bending piezoelectric diaphragm is arranged in the mounting cavity and comprises a middle fixed end and first and second free ends arranged on the two sides of the middle fixed end; a fixing base is arranged at the middle part of the valve body, the bidirectional bending piezoelectric diaphragm is fixedly connected with the valve body through the fixing base; an elastic reset piece is arranged; and a limiting table is arranged. The bidirectional bending piezoelectric diaphragm with the middle fixed and two free ends is adopted to replace the layout mode of two one-way bending diaphragms in the prior art, the number of core driving components is reduced from the original two to one, the miniaturization and light weight of the piezoelectric proportional valve are fundamentally realized, and the cost of piezoelectric material is greatly reduced.

The application discloses a portal lifting stable control feedback system and method applied to a forklift AGV, and the system comprises an IMU, an abnormality judgment module, a speed planning module, a feedforward item determination module, a PID control module and a valve control module. The IMU outputs acceleration data; the abnormality judgment module determines a portal lifting abnormality judgment result according to the acceleration data; the speed planning module obtains a target speed and determines a target acceleration when the portal lifting is not abnormal; the feedforward item determination module determines vertical motion state corresponding data of the portal at the current moment according to the acceleration data, and determines a feedforward item according to the target acceleration and the vertical motion state corresponding data; the PID control module determines a compensated speed tracking control instruction according to the target speed and the feedforward item; and the valve control module determines a proportional valve opening degree according to the control instruction, and executes deceleration stop control when the portal lifting is abnormal. The application can improve the consistency between the portal lifting control and the actual motion state and the operation stability.

This invention relates to a temperature control device and system for die-casting automotive aluminum-magnesium alloy parts, belonging to the field of automotive parts manufacturing technology. It includes a layered temperature measurement module, a zoned heating module, a zoned conformal cooling module, and a main control unit. The layered temperature measurement module is distributed on the surface of the cavity, in the runner, and deep within the mold base. Surface temperature sensing points are integrated into movable hollow ejector pins to eliminate temperature measurement hysteresis and resist injection impact; deep temperature sensing points are equipped with elastic pre-tightening mechanisms to eliminate contact thermal resistance. The zoned conformal cooling module is formed using additive manufacturing, with its three-dimensional flow channel trajectory conforming to the cavity contour and evenly distributed, combined with proportional valves and dual-parameter monitoring of flow and pressure. This invention achieves multi-dimensional precise temperature control from local to macroscopic levels, eliminating heat exchange dead zones and "heat spots" in complex deep cavities, effectively avoiding defects such as casting shrinkage cavities, and improving yield.

This application discloses a control method for a gas water heater, a gas water heater, and a storage medium, relating to the field of water heater technology. The gas water heater includes a fan, at least two burner assemblies, at least two solenoid valves, and a gas proportional valve. At least two burner assemblies are connected to the gas proportional valves, and each burner assembly is connected in series with a corresponding solenoid valve. The method includes: responding to a burner switching command, controlling a target solenoid valve to open or close, and controlling the gas proportional valve and / or the fan to perform a feedforward compensation action corresponding to the burner switching command, so that the change in flame state parameters in the gas water heater after the target solenoid valve opens or closes is less than or equal to a preset value; wherein the target solenoid valve is the solenoid valve corresponding to the burner switching command. This application aims to reduce combustion state fluctuations during burner switching to avoid instantaneous exceedances of pollutant emissions, reduce operating noise, improve the constant temperature effect during bathing, and extend the service life of the equipment.

This application discloses a pressure supply device, relating to the technical field of organoids. The pressure supply device includes: a housing having an installation cavity; a positive pressure supply assembly disposed within the installation cavity, including: a first pipe, a first pump, and a first proportional valve, the first pipe having a first gas inlet and a first gas outlet, the first gas inlet being for communication with a gas source, the first gas outlet being for communication with a positive pressure interface of a culture box, the first pump and the first proportional valve being both installed in the first pipe, and the first proportional valve being located between the first pump and the first gas outlet; and a negative pressure supply assembly disposed within the installation cavity, including: a second pipe, a second pump, and a second proportional valve, the second pipe having a second gas inlet and a second gas outlet, the second pump and the second proportional valve being both installed in the second pipe, the second proportional valve being located between the second pump and the second gas inlet, and the second gas inlet being for communication with a negative pressure interface of a culture box.

1. The name of the design product: proportional valve three-way large flow integrated valve group (PV06). 2. The use of the design product: the design product is used to control the output pressure of fluid medium. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view.

The utility model discloses a kind of composite action control systems of anchor rod drilling machine digital handle switch, specifically related to hydraulic control system technical field.Composite action control system of anchor rod drilling machine digital handle switch, comprising: mode switch M, for output chassis mode signal and drilling mode signal;Digital cross handle switch K is connected with controller H by CAN line, for sending direction operation signal to controller H;The 8 feet and 9 feet of controller H are respectively connected chassis mode signal line and drilling mode signal line of mode switch M, for receiving mode signal;Electric proportional output E, defined as the 99 feet and 25 feet of controller H, is connected to electric proportional valve Q;Electric proportional output F, defined as the 40 feet and 16 feet of controller H, is connected to electric proportional valve G.The composite action control system of anchor rod drilling machine digital handle switch provided by the utility model optimizes operation, panel switch reduces, so that operation becomes simple.

This invention discloses an intelligent temperature control system and method for heavy-duty truck disc brakes, relating to the field of heavy-duty truck braking systems. The control system comprises a brake disc, a micro-vortex tube array, a dual-channel rotary sealing module, a MEMS temperature-wind speed sensing network, a high-speed pressure-flow proportional valve group, and a vehicle domain controller. The MEMS sensing network collects real-time data on the brake disc friction ring temperature and convective wind speed. The domain controller predicts the temperature rise trajectory using a thermo-mechanical coupling model. When the temperature exceeds a threshold, cold-end and hot-end coordinated cooling is initiated. A pulsed airflow from the cold end sweeps tangentially across the friction surface via an air knife to strip away the hot layer, while a micro-airflow from the hot end is injected into the backplate air guide groove to eliminate thermal stress gradients. The flow rates of the two airflows are decoupled and distributed online by the proportional valve based on temperature error. This invention requires no modification to the brake caliper structure, is compatible with ABS / EBS protocols, suppresses heat fade, extends lining life, and improves braking safety margin.

The application relates to a proportional valve spool control and position detection system, method, device and medium. The system comprises a main control unit, an excitation driving unit, a phase detection unit, a feedback signal processing unit, an amplitude detection unit and an LVDT sensor. The proportional valve spool is located between the excitation end of the LVDT sensor and the feedback end of the LVDT sensor, and the sensor excitation end is connected with the excitation driving unit, and the sensor feedback end is connected with the feedback signal processing unit. The system takes the output frequency excitation signal as a reference, detects the phase difference between the frequency excitation signal and the valve spool position feedback signal, can quickly judge the position of the valve spool and control the movement direction of the valve spool based on the phase difference and the type of the LVDT sensor, and can quickly and accurately obtain the opening value of the valve spool by detecting the amplitude of the position feedback signal. Based on the system, the proportional valve spool position detection and movement direction control can be realized quickly, simply, accurately and at low cost.

The application discloses an integrated-amplifier single-feedback closed-loop proportional throttle valve and relates to the technical field of throttle valve production.The integrated-amplifier single-feedback closed-loop proportional throttle valve comprises a main valve, a pilot proportional valve, a displacement sensor and an amplifier, and a single-feedback closed-loop control of the displacement of a main valve core is formed through built-in oil paths and electrical signal feedback.Based on the integrated design of the threaded plug-in type of the main valve and the pilot proportional valve, the integrated amplifier and the displacement sensor are taken as cores to construct a single-feedback closed-loop control loop, the slide valve structure of the pilot proportional valve is matched with accurate electromagnetic control, the flexibility and the anti-sticking ability of the valve core movement are obviously improved, the technical difficulties of the complex structure and the easy sticking of the traditional double-feedback proportional throttle valve are effectively solved, accurate proportional throttle control under the high-pressure large-flow working condition is realized, and the integrated-amplifier single-feedback closed-loop proportional throttle valve has the obvious advantages of compact structure, fast response, strong anti-pollution ability and high reliability.

The application discloses a belt filter press deviation rectifying device and method, and belongs to the technical field of auxiliary equipment of belt filter press.The device comprises a rack, a deviation rectifying roller, a detection rod, a proportional valve, a control rod, a displacement conversion assembly and a deviation rectifying cylinder, and each component is installed on the rack; the detection end of the detection rod is attached to the edge of the filter belt, and converts the filter belt deviation into the displacement of the detection rod; the displacement conversion assembly connects the detection rod and the control rod, and realizes accurate displacement transmission; the proportional valve is matched with a tapered valve core through a V-shaped throttling groove, realizes linear regulation of the air inlet flow, drives the deviation rectifying cylinder to extend and retract, and adjusts the roller seat of the deviation rectifying roller.The deviation rectifying method comprises pre-tightening detection, displacement conversion, deviation rectifying action and reset emergency steps, realizes self-adaptive deviation rectifying of the filter belt "small deviation slow rectification and large deviation fast rectification", and can accurately capture slight deviation, avoids secondary deviation of the filter belt, is stable in operation, has high universality, and can guarantee continuous operation of the belt filter press.

This invention relates to the field of forklift AGV control technology, specifically disclosing a method and system for stable control of forklift arm lifting in forklift AGVs. The method includes: acquiring acceleration data output from an inertial measurement unit and pressure data output from a pressure sensor; determining a compensated lifting control command based on the target speed and acceleration data; and determining the pressure change characterization result, maximum lifting speed, and preset constraints based on the pressure data. When the preset constraint is a speed limit condition, determining the proportional valve opening under the maximum lifting speed constraint to control the forklift arm lifting; and when the preset constraint is a stop condition, outputting a deceleration stop control and executing the deceleration stop. The method and system of this invention can achieve continuous and stable control of the forklift arm lifting process when dynamic fluctuations are caused by changes in the forklift AGV's operating conditions, improving the stability, continuity, and controllability of the forklift arm lifting process.

1. Name of the designed product: Proportional valve (PV09). 2. Use of the designed product: The designed product is used for controlling the output pressure of fluid medium. 3. Design points of the designed product: In shape. 4. Picture or photo best indicating the design points: Perspective view.

This invention relates to a constant pressure control system for an optical cavity based on pump-valve coordination and water immersion sensing, and its active protection method. Belonging to the fields of precision instrument control and industrial automation, the system integrates an electronically controlled proportional valve and an air pump through a pump-valve coordinated pressure control unit. It dynamically adjusts the intake and exhaust flow rates based on an adaptive PID algorithm and a coordinated allocation function, achieving high-precision, rapid, bidirectional adjustment of the optical cavity pressure. Simultaneously, it employs a dual environmental sensing unit including visual perception and capacitive liquid level sensing, which executes constant pressure control and active anti-intrusion monitoring in parallel through an intelligent coordinated control unit. When visual detection identifies a risk of water intrusion, the system proactively limits the pump speed; when the capacitive sensor detects liquid water intrusion, it immediately executes an emergency shutdown. This solves the problem of difficulty in coordinating pressure control and safety assurance in traditional technologies, achieving a unified approach of long-term precise constant pressure and active contamination protection, significantly improving the system's reliability, safety, and intelligence level under complex operating conditions.

This invention relates to the field of slewing drive technology, and discloses a sliding system, adjustment method, and engineering machinery. The sliding system of this invention is applied to the slewing mechanism of engineering machinery, including a hydraulic oil tank, a hydraulic motor, a first pipeline, a second pipeline, and a slewing control module. The hydraulic motor is connected to the hydraulic oil tank, and the two pipelines are respectively connected to its inlet and outlet ends. The slewing control module includes a slewing directional valve, a free-slide proportional valve, and two slewing balance valves. The slewing directional valve can switch between blocking and conducting positions. The slewing balance valve has a load feedback valve core. The free-slide proportional valve is connected in parallel to two pipelines and is connected to a bypass oil circuit and the main machine tilt sensor. Its opening degree is controlled by its current signal. The sliding system of this invention can achieve stepless speed regulation of slewing, reduce hydraulic shock, and prevent slippage by maintaining pressure through the slewing balance valve. Compared with mechanical speed regulation, it is smoother and can achieve independent control of forward and reverse rotation, improving operational safety and stability.

The application relates to a LOCA testing device of a nuclear power plant, which comprises an experiment cabin, a steam supply mechanism and a gas supply mechanism, the steam supply mechanism comprises a steam source and a steam inlet pipe connecting the steam source and the experiment cabin, the gas supply mechanism comprises a gas source and a gas inlet pipe connecting the gas source and the experiment cabin, and a control system is further arranged, a first control valve group is arranged on the steam inlet pipe, a second control valve group is arranged on the gas inlet pipe, the first control valve group and the second control valve group both comprise electromagnetic switch valves and electromagnetic proportional valves which are arranged in parallel, the electromagnetic switch valves and the electromagnetic proportional valves are connected with the control system in control, experiment temperature sensors and experiment pressure sensors for detecting the temperature and the pressure in the cabin are further arranged on the experiment cabin, and the experiment temperature sensors and the experiment pressure sensors are connected with the control system in signal.

The embodiment of the application discloses a kind of control method of walking equipment, control device, walking equipment and storage medium, belong to equipment control field.Walking equipment includes hydraulic pump group and at least two power groups, hydraulic pump group includes at least two hydraulic pumps, each power group includes sequentially connected first proportional valve, high-speed switch valve and motor, each hydraulic pump is connected each first proportional valve, and the first proportional valve in each power group is also connected with corresponding motor, the control method of walking equipment includes: response receives speed mode instruction, the state of high-speed switch valve is switched;According to received walking instruction, the flow mode of hydraulic pump group is switched;Based on speed mode instruction and the flow mode of hydraulic pump group, determine current speed range;According to current speed range, determine the target speed corresponding to walking instruction;Based on target speed, adjust the opening area of first proportional valve, to control the rotating speed of motor.By switching the state of high-speed valve and hydraulic pump, the speed of walking equipment can be accurately controlled according to actual road conditions.

The application discloses a pressure relief system and a pressure relief system control method. The pressure relief system comprises a main oil cylinder, an oil tank, a control valve and a proportional valve, the main oil cylinder comprises a piston, the piston divides the inner cavity of the main oil cylinder into a first cavity and a second cavity, the oil tank is communicated with the first cavity through a liquid filling valve, the control valve controls the opening and closing of the liquid filling valve, when the liquid filling valve is closed, the proportional valve is communicated with the first cavity through a first oil path, the proportional valve is communicated with the oil tank through the control valve, and the proportional valve can relieve the pressure in the inner cavity of the main oil cylinder. When relieving the pressure, the opening degree of the proportional valve can be infinitely adjusted according to the pressure in the inner cavity of the main oil cylinder and / or the relieving flow. The pressure relief system control method comprises the pressure relief system. By adopting the application, uniform-speed pressure relief and flow uniform control can be realized, various working conditions can be flexibly adapted, and the pressure relief stability and efficiency are considered.

This invention relates to the field of bulldozer technology and provides a hydraulic control system and method for bulldozers. It recovers the energy generated by the descent of the bulldozer's working device through an accumulator. When the working device is lifted or other mechanisms require hydraulic pressure, a solenoid valve is opened. A solenoid proportional valve opens its valve core according to the compensation flow required by the second inlet valve. The oil in the accumulator provides a corresponding flow rate according to the opening degree of the solenoid proportional valve. The solenoid proportional valve sends the hydraulic oil from the accumulator through a first check valve to the inlet of the second inlet valve. The solenoid valve receives a compensation signal and opens the oil outlet passage of the accumulator. The hydraulic energy stored in the accumulator, after being regulated by the control terminal of the solenoid proportional valve, is then delivered through the first check valve to the inlet of the second inlet valve and subsequently enters the lifting chamber of the lifting cylinder. This compensates for the lifting of the blade, achieving stable and controllable oil flow and ensuring smooth movement of the working device or other actuators.

The application relates to the technical field of dynamic wind force auxiliary muck discharging devices, and particularly discloses a dynamic wind force auxiliary muck discharging device for a full-face tunnel boring machine, which comprises a spraying assembly, a muck amount monitoring assembly and an intelligent control assembly. The spraying assembly comprises an annular distributor and a gas supply pipeline. The annular distributor is fixedly arranged in a cutter head on the full-face tunnel boring machine. A plurality of air inlet pipes and air outlet pipes are fixedly arranged on the annular distributor and extend out of the cutter head. An electric proportional valve is fixedly arranged on the gas supply pipeline. The muck amount monitoring assembly is fixedly arranged on the full-face tunnel boring machine. The intelligent control assembly is fixedly arranged outside the full-face tunnel boring machine. The electric proportional valve, the muck amount monitoring assembly and the full-face tunnel boring machine are electrically connected with the intelligent control assembly. The dynamic wind force auxiliary muck discharging device can start wind force auxiliary muck discharging. High-pressure gas is sprayed out of the plurality of air outlet pipes on the annular distributor to clean the muck accumulated or adhered to the cutter head.

The application relates to a rolling mill calendering roller flattening force control method, characterized by the following specific steps: step S1, hardware improvement: angle encoders are installed on the swing arm pivot fulcrums of the driving side and the operating side of the rolling mill calendering roller, swing arm angles of the driving side and the operating side are collected in real time, step S2, mathematical model construction: a model is established based on the swing arm angle data, and step S3, PI closed loop control; the application compares the actual force (T dact , T Oact measured by a pressure sensor) of the hydraulic cylinder with the given force (T dref , T Oref ), calculates the deviation (Delta T d , Delta T O ), dynamically adjusts the input current of the proportional valve of the hydraulic cylinder on the two sides through a PI regulator, compensates the deviation in real time, ensures that the flattening forces (F d , F O ) on the two sides are consistent, and thus the unbalance of the forces on the two sides caused by mechanical wear and installation errors can be eliminated, and defects such as one-side waves and layering can be inhibited.

The application discloses a kind of hydraulic proportional valve data acquisition card automatic calibration system and method thereof, wherein system includes host computer data acquisition module, calibrated test bench, data acquisition card to be calibrated, electromagnetic valve, displacement sensor, power supply module;Host computer data acquisition module issues calibration command and parameter to data acquisition card;Data acquisition card is used to receive calibration command and parameter issued by host computer data acquisition module, after signal excitation is carried out to electromagnetic valve or displacement sensor, corresponding data original code is collected;Test bench collects corresponding physical quantity data;Data acquisition card will data original code, physical quantity data form sample, send to host computer data acquisition module according to calibration algorithm to complete calibration;Power supply module is used to provide power support for electromagnetic valve, displacement sensor, data acquisition card, test bench;The application carries out automatic adjustment to sensor in hydraulic proportional valve, improves the calibration efficiency of sensor in hydraulic proportional valve.

Provided is an electromagnetic proportional valve, a construction machine. The present invention is made in view of problems of an electromagnetic proportional valve provided with an electromagnetic valve that supplies a working fluid to an actuator, and aims to provide an electromagnetic proportional valve that can easily change a structure. An electromagnetic proportional valve (10) is provided with a proportional valve main body (12) and an electromagnetic valve control section (14). The proportional valve main body (12) supplies a working fluid (Fd) to an actuator (56) that drives a driven body. The electromagnetic valve control section (14) is provided integrally with the proportional valve main body (12) in order to control the proportional valve main body (12).

The application discloses a laser cutting gas path system and a laser cutting device. The laser cutting gas path system comprises at least one gas pipeline, a proportional valve and a cutting head. The gas pipeline comprises a gas source, a gas filter, a solenoid valve and a check valve connected in sequence. The inlet of the proportional valve is connected with the outlet of the check valve of each gas pipeline and communicates with one gas pipeline, and the proportional valve is used for adjusting the gas pressure of the gas output by the gas pipeline. The gas path inlet of the cutting head is connected with the outlet of the proportional valve. One or more gas pipelines share one proportional valve, the structural complexity of the laser cutting gas path system is simplified, and the system hardware cost and maintenance difficulty are effectively reduced under the premise of ensuring that the gas pressure can be normally and accurately adjusted.

The utility model relates to a kind of soft breathing auxiliary system, comprising: soft pressing module, electromagnetic valve, sensor unit, flow proportional valve, mute air pump, opto-coupler relay, analog-digital converter, main controller, battery pack and host computer, wherein the mute air pump, flow proportional valve, soft pressing module and electromagnetic valve are sequentially connected by trachea, the soft pressing module is connected with sensor unit, the sensor unit is connected with main controller by analog-digital converter, the main controller is also connected with flow proportional valve by opto-coupler relay, the host computer is connected with main controller, and the battery pack is connected with main controller, flow proportional valve, electromagnetic valve and sensor unit respectively.The utility model has the advantages of light weight, large output force, good man-machine compatibility, etc., by lightweight wearable pressing unit design, the rehabilitation method of physician can be effectively simulated, and the use demand of portable home respiratory assistance is met.

This invention discloses a porous material permeability detection device, comprising a pressure tank and a sample holder. One end of an inlet pipe is connected to an external gas source, and the other end extends into the upper part of the inner cavity of the pressure tank. A first proportional valve is installed on the inlet pipe. The lower end of the outlet pipe extends into the lower part of the inner cavity of the pressure tank, and the upper end is connected to the lower inlet of the sample holder. One end of a guide pipe is connected to the upper outlet of the sample holder, and the other end extends into the inner cavity of a liquid collector. The liquid collector is placed on an electronic scale. A pressure sensor is installed on the outlet pipe. The advantages of this invention are: it can be applied to the permeability of porous materials through liquid and gaseous media, and can also be used to determine the permeability under the action of gas and liquid mixtures, thus having a wider range of applications.

Disclosed example normally-open proportional valves include: a body comprising an inlet, an outlet, and an interior volume; a poppet configured to move within the interior volume between a seated position in which the poppet blocks gas flow between the inlet and the outlet, a fully opened position in which gas is permitted to flow between the inlet and the outlet, and positions between the seated position and the fully opened position; a biasing element configured to bias the poppet toward the seated position; a solenoid having a coil and a core; a permanent magnet positioned to bias the poppet away from the seated position; and control circuitry configured to selectively control the solenoid to control a net force of the permanent magnet and the solenoid on the poppet to control a position of the poppet.