Disclosed herein are reluctance actuators and methods for feedback control of their applied force. Embodiments of the reluctance actuators include an electromagnet positioned to deflect a metallic plate to provide a haptic output. The control of the force is provided without force sensors (sensorless control) by monitoring voltage and/or current (V/I) applied during an actuation. For a given intended force output, an electrical parameter value (flux, current, or other parameter) is read from a look up table (LUT). The LUT may store a present value of the inductance of the reluctance actuator. The feedback control may be a quasi-static control in which the LUT is updated after actuation based on the monitored V/I. The feedback control may be real-time, with a controller comparing an estimated electrical parameter value based on the measured V/I with the value from the LUT.

A semiconductor device includes an output driving circuit configured to output an output current to an output terminal; a detection resistor connected between the output terminal and the output driving circuit; an amplification unit configured to output an analog detection signal generated by amplifying a voltage between both ends of the detection resistor; a current generation circuit configured to output a reference current; a reference resistor connected between the current generation circuit and a ground and configured to output a reference voltage according to the reference current; an A/D converter configured to convert the analog detection signal into a digital detection signal using the reference voltage as a reference; and a control circuit configured to control the output current output from the output driving circuit according to the digital detection signal. The detection resistor has a same temperature characteristics as the reference resistor.

Methods and systems are provided for a solenoid actuator. In one example, a method may include adjusting a switching frequency during an activation cycle of the solenoid actuator to a lower switching frequency relative to other phases of the activation cycle.

Systems and methods for a solenoid supervisory detection system which can detect the presence or absence of a solenoid plunger within a solenoid coil. These systems can be used to verify correct reassembly of a solenoid valve after it has been disassembled for testing.

An electromagnetic valve, such as a pilot valve for controlling a main valve or a pilot-operated valve in a divert-air valve, may include at least one valve member in operative connection with a plunger movable along a first axis and at least one coil element. A movement of the plunger or of the valve member is caused by an energization of the coil element, and at least one sensing element by which at least one parameter of the coil element is detectable. The position of the plunger and/or of the valve member can be determined by the parameter. The valve may be part of a divert-air valve system

An apparatus and method of detecting movement of a plunger of the solenoid includes detecting a peak (I.sub.PEAK) in a current signal applied to a coil of the solenoid. A predetermined threshold is added to the current signal applied to the coil of the solenoid to generate a level shifted signal. The level shifted signal and the peak signal are compared to detect movement of a plunger of the solenoid.

A bistable solenoid valve device for a fluid system is provided. The bistable solenoid valve device comprises a bistable solenoid valve. The bistable solenoid valve comprises a permanent magnet. The bistable solenoid valve further comprises an armature displaceable between a first armature position and a second armature position. The bistable solenoid valve further comprises a first switching coil for energization for a displacement of the armature into the first armature position. The bistable solenoid valve further comprises a second switching coil for energization for a displacement of the armature into the second armature position. The bistable solenoid valve further comprises an evaluation device adapted to measure an induced coil voltage, an induced coil current, or both the induced coil voltage and the induced coil current, at one or more of the non-energized switching coils. The evaluation device is further adapted to assess a switching behavior of the armature.

A semiconductor device has a drive transistor coupled to a load and a current detection circuit. The current detection circuit includes: an operational amplifier amplifying a potential difference between voltage of a first terminal and voltage of a second terminal; a sense transistor passing sense current between the first terminal and the drive transistor; a voltage supply circuit having a first current source and supplying voltage higher than voltage supplied to the grounding voltage terminal to the second terminal; a third terminal outputting current based on the sense current; a second current source coupled between the third terminal and the grounding voltage terminal; and a current source control circuit controlling current of the first and second current sources. Detection current detected by the current detection circuit is current obtained by subtracting the current of the second current source from the current based on the sense current.

A method for end position detection in an electromagnetic, bistable actuator (101) includes applying excitation energy to the actuator (101) with the aid of a two-position controller while an armature (103) of the actuator (101) is in an end position, and determining at least one value of a switching frequency of the two-position controller.

A method for switching over a solenoid valve having a movable valve body between a first position and a second position, wherein the method comprises at least the following method steps: a) adjusting a switching current to a pre-energization current intensity, in which the valve body remains in the present position, for a first time interval, and b) adjusting the switching current to a first switchover current intensity, which introduces a switchover movement of the valve body, for a second time interval.