An electromagnetic actuation system includes an actuator having an electrical coil, a magnetic core, and an armature. The system further includes a controllable bi-directional drive circuit for selectively driving current through the electrical coil in either of two directions. The control module provides an actuator command to the drive circuit effective to drive current through the electrical coil in a first direction to actuate the armature and in a second direction subsequent to armature actuation to oppose residual flux within the actuator. The control module includes a feed forward control module configured to adapt the actuator command to converge residual flux within the actuator to a preferred flux level.

A method for providing consistent actuator events for each of a plurality of consecutive actuator events of an electromagnetic actuator, includes applying a first bi-directional current waveform for a first actuator event and applying a second bi-directional current waveform for a second actuator event immediately subsequent to the first actuator event. The first bi-directional current waveform includes applying current in a first direction when the actuator is commanded to an actuated position and applying current in a reversed second direction when the actuator is commanded to a rest position. The second bi-directional current waveform includes applying current in the reversed second direction when the actuator is commanded to an actuated position and applying current in the first direction when the actuator is commanded to a rest position.

A method for operating an electromagnetic actuator includes an actuation event utilizing a current waveform for the actuator characterized by an initial peak pull-in current in a first direction of current flow when the actuator is commanded to an actuated position; and a reversed peak current in a second opposite direction of current flow applied after the actuator is commanded to a rest position. The reversed peak current has a magnitude that is greater than the magnitude of the initial peak pull-in current.

An electronic circuit has a current generator circuit that generates a two-state output current signal for which a transition between states is altered.

A circuit and a method for improving efficiency by use of external inductor for temperature control, wherein the operating temperature of a field effect transistor is calculated by the inductor voltage. The change in operating temperature is used to adjust and control the voltage of the variable voltage gate drive module. When the operating temperature rises, the input voltage of the gate increases accordingly; when the operating temperature decreases, the input voltage of the gate decreases accordingly, thereby achieving the efficiency of regulating light and heavy loads.

A circuit and a method for improving efficiency by use of external inductor for temperature control, wherein the operating temperature of a field effect transistor is calculated by the inductor voltage. The change in operating temperature is used to adjust and control the voltage of the variable voltage gate drive module. When the operating temperature rises, the input voltage of the gate increases accordingly; when the operating temperature decreases, the input voltage of the gate decreases accordingly, thereby achieving the efficiency of regulating light and heavy loads.

An exemplary arrangement and method for a power semiconductor switch, where a first current between a first electrode and a second electrode can be controlled based on a control voltage between a third electrode and the first electrode. The arrangement includes an inductance connected in series with the power semiconductor switch, wherein a first end of the inductance is connected to the first electrode, first measuring source for generating a first measurement voltage based on the first end's voltage with respect to a reference potential, second measuring source for generating a second measurement voltage on the basis of the inductance's second end voltage with respect to the reference potential, a comparator for comparing the first measurement voltage with the second measurement voltage, and driver for generating the control voltage. The driver being configured to generate a first control voltage level and a second voltage level of the control voltage.

A keyboard key structure comprising a key stem, a contact-based mechanical trigger, and a contactless analog key switch. The key stem is configured to be depressed and move along a linear path over a range of operation. The contact-based mechanical trigger is configured to activate after the key stem is depressed a threshold distance in the range of operation. In response to the contact-based mechanical trigger activating, the contactless analog key switch is configured to detect, at a sample rate, a position of the key stem between the threshold distance and an end of the range of operation after the key stem is depressed. The contact-based mechanical trigger can be a galvanic-type key switch. The contactless analog key switch can be one of an optical key switch, a magnetic key switch, or an inductive key switch.

A keyboard key structure comprising a key stem, a contact-based mechanical trigger, and a contactless analog key switch. The key stem is configured to be depressed and move along a linear path over a range of operation. The contact-based mechanical trigger is configured to activate after the key stem is depressed a threshold distance in the range of operation. In response to the contact-based mechanical trigger activating, the contactless analog key switch is configured to detect, at a sample rate, a position of the key stem between the threshold distance and an end of the range of operation after the key stem is depressed. The contact-based mechanical trigger can be a galvanic-type key switch. The contactless analog key switch can be one of an optical key switch, a magnetic key switch, or an inductive key switch.