There is provided a transformation control device of a transformation chopper circuit that transforms an input by turning on and off a current using a switch and outputs the transformed input. The transformation control device controls at least an ON/OFF state of a main switch by acquiring an output voltage of the transformation chopper circuit in a case where the main switch is in an ON state, the main switch being turned on in a case where energy is accumulated in an inductor.

The present disclosure provides a coil driving device comprising: an input voltage sensing unit for sensing an input voltage; a switch unit configured to make a switching operation to supply a driving current to a coil; a PWM circuit unit for outputting a pulse width modulation (PWM) signal for the switching operation of the switch unit; an impedance adjustment unit for varying an impedance value such that the PWM signal is adjusted, thereby limiting the driving current; and a control unit for causing the impedance adjustment unit to vary the impedance value on the basis of the input voltage, thereby adjusting at least one of the duty ratio of the PWM signal and the frequency thereof.

Methods and systems for operating an on-off valve coupled to a system for regulating a system parameter are described herein. The method comprises setting an upper limit on a duty cycle of a pulse width modulation (PWM) signal for controlling the valve, generating the PWM signal with the duty cycle less than or equal to the upper limit and applying the PWM signal to the valve, monitoring the system parameter as the PWM signal is applied, and increasing the upper limit on the duty cycle over time until the system parameter reaches a target.

A solenoid valve diagnostic apparatus includes a plurality of solenoid valves that open or close an entrance/exit opening of a fuel tank, a current sensor that measures an operating current of the solenoid valves, and a controller that diagnoses whether the solenoid valves fail, based on the operating current measured by the current sensor.

In an example, a system for applying an agricultural product includes a valve and a solenoid. For instance, the valve includes a coil that generates a magnetic flux. The system includes a valve controller. The valve controller is configured to measure one or more electrical characteristics of at least one of the coil or a dissipation element. In some examples, the valve controller determines an actual duty cycle of a valve operator of the valve using the measured electrical characteristics. The valve controller determines a magnetic flux correction, for instance based on a difference between the actual duty cycle and a specified duty cycle. The valve controller operates the valve operator according to the specified magnetic flux and the magnetic flux correction to guide the actual duty cycle toward the specified duty cycle.

There is provided a transformation control device of a transformation chopper circuit that transforms an input by turning on and off a current using a switch and outputs the transformed input. The transformation control device controls at least an ON/OFF state of a main switch by acquiring an output voltage of the transformation chopper circuit in a case where the main switch is in an ON state, the main switch being turned on in a case where energy is accumulated in an inductor.

A coil actuator for low and medium voltage applications comprising a coil electromagnet provided with a single coil winding and a movable anchor and a power and control unit comprising: a power circuit operatively coupled with said coil electromagnet, said power circuit comprising input terminals, at which said power circuit receives an input voltage; a PWM controller operatively coupled with said power circuit, said PWM controller being adapted to control an input current flowing through said power circuit to obtain and maintain an average operating level selected an excitation current feeding said coil electromagnet. Said PWM controller is adapted to set a plurality of reference values for said input current to control said input current, each reference value for said input current being selected among said plurality of reference values depending on the behavior of said input voltage.

In an example, a system for applying an agricultural product includes a valve and a solenoid. For instance, the valve includes a coil that generates a magnetic flux. The system includes a valve controller. The valve controller is configured to measure one or more electrical characteristics of at least one of the coil or a dissipation element. In some examples, the valve controller determines an actual duty cycle of a valve operator of the valve using the measured electrical characteristics. The valve controller determines a magnetic flux correction, for instance based on a difference between the actual duty cycle and a specified duty cycle. The valve controller operates the valve operator according to the specified magnetic flux and the magnetic flux correction to guide the actual duty cycle toward the specified duty cycle.

A method for modulating a valve regulating the flow rate of gas towards a burner is presented. The valve with the associated closure member configured to operate with a predetermined characteristic curve, the flow rate delivered being proportionally related to the strength of a first current signal sent to the modulator such that the flow rate can be modulated, using the proportionality, within a range of modulation between a maximum flow rate and a minimum flow rate. To deliver controlled gas flow rates that are below the minimum flow rate, the modulator is driven with a second PWM voltage signal capable of generating a particular second PWM current signal, to move the closure member of the valve according to the second signal. First and second time intervals correspond to successive durations of high signal and low signal, respectively, the sum being equal to a period of the second signal.

An electromagnetic switching-valve position detection system includes: an electric current control circuit in which an electric current from a power supply is smoothed to be a direct current, and is turned into a pulse wave alternating current, the pulse wave alternating current being transmitted to the secondary side and outputted as a smoothed direct current; a carrier wave generator configured to superimpose a high frequency carrier wave for position detection on a signal wave of the electric current command; and a detecting unit configured to extract a carrier wave frequency component for the position detection from a voltage feedback signal of the solenoid, detect a voltage amplitude from the frequency component, and obtain an amplitude signal. The control unit has a position determining unit configured to determine a position of the valve spool, and a determination circuit configured to output a valve position signal based on the determination signal.