A current control device includes a target setting unit, a storage unit, an oil pressure ratio calculation unit, a specific current detection unit and a correction unit. The target setting unit adds a dither amplitude to a target current so that the current of the solenoid periodically changes at a dither cycle period longer than a PWM cycle period of the solenoid. The storage unit stores a stroke-current relationship between a stroke of the spool and the current of the solenoid. The oil pressure ratio calculation unit calculates an oil pressure ratio which is a value calculated by dividing an amplitude of the output oil pressure by an average value of the output oil pressure. The specific current detection unit detects a specific current based on the oil pressure ratio. The correction unit corrects the stroke-current relationship based on the specific stroke and the specific current.

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

A system for driving an inductive load of an appliance is provided. The system includes a direct current (DC) bus of the appliance. The DC bus is coupled to the inductive load of the appliance. The system includes a transistor having a first terminal, a second terminal, and a third terminal. The first terminal is coupled to the inductive load of the appliance. The second terminal is coupled to ground. The system includes a controller coupled to the third terminal of the transistor. The controller is configured to control operation of the transistor to drive the inductive load of the appliance.

A device for operating an electrical consumer, in particular a solenoid valve, including at least one first circuit which encompasses an activatable first switch and a first freewheeling unit connected or connectable in parallel to the consumer, and including a control unit which is designed for activating the first switch in order to energize the consumer with a predefinable electric current with the aid of pulse width modulation. It is provided that the circuit encompasses at least one second switch and one second freewheeling unit, which is connected or connectable in parallel to the consumer, and that the control unit is designed for activating the second switch in a phase-shifted manner with respect to the first switch in order to energize the consumer.

Embodiments of the present disclosure provide method, controller and system for regulating a current of a coil. The method comprises: obtaining a first sample value of the current of the coil at a first moment, the first sample value being associated with a duty cycle of a PWM signal applied to a control end of a switch and the switch being coupled in series with the coil; obtaining a second sample value of the current of the coil at a second moment; determining a difference value between the first and the second sample values; and updating the duty cycle of the PWM signal based on the difference value to regulate the current of the coil. According to embodiments of the present disclosure, the inrush current of the coil generated at the moment of closing the contactor can be limited to a target current value, so as to increase the service life of the contactor.

A control apparatus for controlling a linear solenoid by controlling a driving current supplied to the linear solenoid through a feedback control. The feedback control is executed by a feedback control system having parameters that are determined in accordance with an ILQ design method. In a frequency characteristic of a gain of a transfer function representing a ratio of an output to a disturbance in the feedback control system, the gain is lower than 0[dB] throughout all frequency ranges.

A method for determining a switching state of a valve, an inductance variable being determined on the basis of current and voltage measurements and the switching state being determined on the basis of the inductance variable. Also disclosed is a solenoid valve assembly for carrying out such a method.

A method for determining a switching state of a valve that is actuated by a coil, wherein the method includes: respectively ascertaining a current flowing through the coil and a voltage applied to the coil at several times which follow one another with a prespecified time interval, calculating an inductance variable of the coil based on the currents, the voltage and the time interval, and determining the switching state based on the inductance variable. Also disclosed is a solenoid valve assembly.

A method for actuating a solenoid valve, which is used for throughflow rate control, of an agricultural spreading machine, wherein the solenoid valve has a valve armature, comprising: energizing the solenoid valve in order to cause an opening movement of the valve armature and/or in order to hold the valve armature in an open position in which the solenoid valve is open, interrupting or changing the energization of the solenoid valve in order to cause a closing movement of the valve armature in the direction of a valve seat, and causing a reduction in the movement speed of the valve armature during the closing movement of the valve armature.

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.