A method for determining a reference current curve for a fuel injector having a magnetic coil drive in an internal combustion engine of a motor vehicle includes: (a) applying a first voltage pulse to the magnetic coil drive to open the fuel injector, (b) applying a holding voltage to the magnetic coil drive to hold the fuel injector open, (c) switching off the holding voltage, (d) waiting for substantially no current to flow through the magnetic coil drive for a predetermined time period that is sufficiently short that the fuel injector remains open, (e) applying a second voltage pulse to the magnetic coil drive, and (f) recording a time-based curve of the current that flows through the magnetic coil drive during the second voltage pulse, which forms the reference current curve. This reference current curve is used for determining a time of a predetermined opening state of the fuel injector.

The present invention accurately estimates the opening state of a solenoid valve using a feature amount based on driving current information of the solenoid valve. A solenoid valve abnormality detection device, which uses a driving current pattern associated with valve opening of a solenoid valve and detected by a current sensor to detect an abnormality of the solenoid valve, comprises: a feature amount extraction unit that determines a feature amount of a driving current pattern associated with valve opening of the solenoid valve within a predetermined detection period; a feature amount correction unit that estimates the valve temperature of the solenoid valve; and an opening state estimation unit that estimates the opening state of the solenoid valve using the feature amount value corrected by the feature amount correction unit.

A device for monitoring the operation of a solenoid valve. This device includes a circuit for powering the coil of a solenoid valve, with terminals designed for connection to the coil, a power supply switching transistor, and a measurement resistor. The device also includes a microprocessor-based measurement system that includes an analogue-to-digital converter with a consumed current measurement channel connected to the measurement resistor and a consumed current amplified measurement channel connected to the consumed current measurement channel via an adjustable amplifier. The system is designed to deactivate the power supply switching transistor when a voltage exceeding a threshold value is detected on the consumed current measurement channel, and control the gain of the adjustable amplifier so that the signal at the input of the consumed current amplified measurement channel is within the measurement range of this channel.

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 test bench for a contactor bulb includes: a frame, configured to fix the bulb therein, and an actuation device, borne by the frame and including an output shaft, centred on a longitudinal axis and translationally movable with respect to the frame parallel to the longitudinal axis between a front position and a rear position, the output shaft being configured to be connected to an actuation rod of the bulb. The actuation device is a moving magnet electromagnetic actuator.

An assembly consisting of a control member which comprises a carrier, an operating part movably supported on the carrier, an electromagnetic actuator comprising an armature and a coil for driving the operating part movingly relative to the carrier is provided. The assembly further comprises an electronic control system connected in an electrically conductive manner with the electromagnetic actuator for applying a control voltage to the electromagnetic actuator for a predetermined control period in a control step in order to generate a haptic feedback; a measuring circuit connected in an electrically conductive manner to the electromagnetic actuator for measuring a current present at the electromagnetic actor and for generating a measuring signal proportional thereto; and an evaluation unit connected in an electrically conductive manner at least to the measuring circuit and designed, in a measuring step offset in time relative to the control step, to apply a measuring voltage to the electromagnetic actuator by the electronic control system for a predetermined test period shorter than the control period, in order to measure by the measuring circuit the current which arises at the electromagnetic actuator as the test period elapses due to the application of the measuring voltage and to generate a measuring signal proportional thereto, and in order to obtain a characteristic value of the actuator based on the measuring signal.

In a method for operating a magnetic switching element, at least one connection of at least one sensor device is connected to at least one connection of a coil of the magnetic switching element, and at least one measuring state is established in which the at least one connection of the coil is largely at least temporarily decoupled from a ground, a voltage source, and/or a current source activating the coil, and at least one auxiliary voltage and/or at least one auxiliary current is/are applied to the at least one connection of the coil in the measuring state, and at least one sensor signal is ascertained from at least one electrical potential, at least one potential difference, and/or at least one current flowing at the connections of the coil.

Systems and methods for detecting a plunger movement condition with respect to a solenoid coil are described. A method may include generating a first derivative signal waveform of a current flowing in the solenoid coil, identifying whether there is at least one zero crossing point in the first derivative signal waveform, and detecting the plunger movement condition according to an identification result indicating whether there is at least one zero crossing point in the first derivative signal waveform.

A computer-implemented method for estimating a health state of a solenoid valve including a solenoid for supporting a process control system. The method includes the steps of monitoring a current passing through the solenoid, determining a time period between an instant of initiating a state change of the solenoid valve and an instant when the time derivative of the current is discontinue, comparing the time period with a reference time period indicative for the health state of the solenoid valve thereby determining the health state.