In some examples, a rotatable transformer includes a first core half mounted on a rotor and a second core half mounted on a stator. Each core half may include a first element having a ring shape and constructed of a laminated sheet material layered in a radial direction from an axis of rotation of the rotor, and a second element having a ring shape and constructed of a laminated sheet material layered in a direction of the axis of rotation. The second element may be positioned adjacent to the first element and at angle thereto, and a coil winding may be located in an area of the angle formed by the first element and the second element. The first core half and the second core half may be positioned adjacent to each other with a gap there between. The gap may be conical about the axis of rotation.

Embodiments herein describe a variable inductor containing a capillary. The capillary includes an eutectic conductive liquid (e.g., EGaIn) containing suspended magnetic particles and an electrolyte (e.g., NaOH). In one embodiment, the variable inductor has a pair of electrodes (e.g., negative and positive electrodes) at the respective ends of the capillary to seal the eutectic conductive liquid and the electrolyte. The variable inductor also includes an inductor coil disposed around the capillary, and the inductor coil is connected to a circuit and provides inductance for the connected circuit. Using a DC voltage between the pair of electrodes, the eutectic conductive liquid can extend inside the capillary, which in turn, causes the variable inductor to have a desired inductance.

Apparatuses, systems, and associated methods of assembly are described that provide for improved sensor devices. An example sensor device includes a bobbin tube that defines a hollow interior. The device includes a primary coil element wound around the bobbin tube configured to, in response to a current input, generate a primary magnetic flux and includes a secondary coil element wound around the primary coil element. In an instance in which the bobbin tube receives a probe assembly therein, magnetic interaction between the probe assembly and the primary coil element is configured to induce a signal in the secondary coil element. Furthermore, a pitch of the secondary coil element varies according to a non-linear, polynomial function along a second length of the bobbin tube so as to reduce linearity error of the sensor device.

Apparatuses, systems, and associated methods of assembly are described that provide for improved sensor devices. An example sensor device includes a bobbin tube that defines a hollow interior. The device includes a primary coil element wound around the bobbin tube configured to, in response to a current input, generate a primary magnetic flux and includes a secondary coil element wound around the primary coil element. In an instance in which the bobbin tube receives a probe assembly therein, magnetic interaction between the probe assembly and the primary coil element is configured to induce a signal in the secondary coil element. Furthermore, a pitch of the secondary coil element varies according to a non-linear, polynomial function along a second length of the bobbin tube so as to reduce linearity error of the sensor device.

Tunable electronic units and associated systems, as well as methods for tuning characteristic properties of soft electronic units (e.g., inductance, capacitance, and resistance) and fabricating soft tunable planar inductors, axial inductors, capacitors, and resistors, are provided. Disclosed systems and methods enable standardized tuning of different types of soft electronic units (e.g., including a soft inductor, capacitor, and resistor, etc.), and enable remote tuning while maintaining a tuned value without expending power. In certain embodiments, electrical properties of the soft electronic units are tuned using a mobile component (e.g., ferrofluid and iron powder) dragged with a permanent magnet inside a soft fluidic channel. This may be used for applications and devices which need to be soft and flexible, such as implantable electronics, wearable devices, and skin electronics.

A system for determining an amplitude of a sinusoidal output waveform from a sensor includes a controller configured to provide a sample signal having a sample frequency that is four times a frequency of a sinusoidal excitation waveform provided to the sensor. The sensor has inductively-coupled primary and secondary windings that produce the sinusoidal output waveform from the secondary winding when the excitation waveform is provided to the primary winding. An analog-to-digital converter measures a first and second voltage of the sensor waveform separated in time by the period of the sample frequency, and the system calculates the amplitude based on the measurements of the first and second voltages.

A system for determining an amplitude of a sinusoidal output waveform from a sensor includes a controller configured to provide a sample signal having a sample frequency that is four times a frequency of a sinusoidal excitation waveform provided to the sensor. The sensor has inductively-coupled primary and secondary windings that produce the sinusoidal output waveform from the secondary winding when the excitation waveform is provided to the primary winding. An analog-to-digital converter measures a first and second voltage of the sensor waveform separated in time by the period of the sample frequency, and the system calculates the amplitude based on the measurements of the first and second voltages.

The current transformer includes a magnetic circuit made of magnetic material that is intended to be placed around a primary conductor, and a secondary winding that is wound onto a portion of the magnetic circuit in order to deliver a secondary current to processing circuits. In this current transformer the magnetic circuit includes at least one device for varying the magnetization of a portion of the magnetic circuit according to the temperature in order to limit or to decrease the magnetic flux in the magnetic circuit when the temperature of the magnetic circuit increases. The protection device and the electrical circuit breaker include such a transformer.

A resolver system includes a rotatable primary winding, a secondary winding fixed relative to the rotatable primary winding, a tertiary winding fixed relative to the rotatable primary winding and positioned /2 radians out of phase with respect to the fixed secondary winding, an excitation module electrically connected to the rotatable primary winding and configured to provide an excitation signal to the rotatable primary winding where the excitation signal is an alternating current waveform having a fundamental frequency, and a controller electrically connected to the secondary winding and configured to sample a voltage across the secondary winding at 18 times the fundamental frequency, sample a voltage across the tertiary winding at 18 times the fundamental frequency, and determine an amplitude of the fundamental frequency based on the sampled voltages across the secondary and tertiary windings, where the alternating current waveform includes a third harmonic frequency.

A resolver system includes a rotatable primary winding, a secondary winding fixed relative to the rotatable primary winding, a tertiary winding fixed relative to the rotatable primary winding and positioned /2 radians out of phase with respect to the fixed secondary winding, an excitation module electrically connected to the rotatable primary winding and configured to provide an excitation signal to the rotatable primary winding where the excitation signal is an alternating current waveform having a fundamental frequency, and a controller electrically connected to the secondary winding and configured to sample a voltage across the secondary winding at 18 times the fundamental frequency, sample a voltage across the tertiary winding at 18 times the fundamental frequency, and determine an amplitude of the fundamental frequency based on the sampled voltages across the secondary and tertiary windings, where the alternating current waveform includes a third harmonic frequency.