An evaluation circuit, system, and method for evaluating a capacitive or inductive sensor includes first and second measurement connections to which sensors and/or reference elements are connected, first and second charging and discharging circuits that respectively output first and second charging and discharging signals to the first and second measurement connections. A comparator circuit compares the temporal behavior of the first and second charging and discharging signals. An integrator circuit produces an output voltage that changes as a function of the voltage at the output of the comparator circuit. The output voltage of the integrator circuit is connected to the first or second measurement connection to adjust the respective first or second charging and discharging signal. A measurement signal derived from the output voltage of the integrator circuit is a measure of impedance differences between the sensors or reference elements at the first and second measurement connections.

A system may include a resistive-inductive-capacitive sensor, a driver configured to drive the resistive-inductive-capacitive sensor at a driving frequency, a measurement circuit communicatively coupled to the resistive-inductive-capacitive sensor and configured to measure phase information and amplitude associated with the resistive-inductive-capacitive sensor, and a noise detection circuit communicatively coupled to the measurement circuit and configured to determine a presence of external interference in the system based on at least one of the phase information and the amplitude information.

In an example, a circuit includes an emulated current generator configured to provide an emulated current signal responsive to a charge current and a discharge current. The emulated current signal can be representative of an emulated current through an output inductor. A comparator is configured to provide a comparator signal responsive to the emulated current signal and sensed current signal representative of a measure of current through the output inductor. An inductor code counter is configured to adjust an inductor code count value responsive to the comparator signal. A slope of the emulated current signal can be adjusted responsive to the inductor code count value.

Object detection for wireless power transmitters and related systems, methods, and devices are disclosed. A controller for a wireless power transmitter is configured to receive a measurement voltage potential responsive to a tank circuit signal at a tank circuit, provide an alternating current (AC) signal to each of the plurality of transmit coils one at a time, and determine at least one of a resonant frequency and a quality factor (Q-factor) of the tank circuit responsive to each selected transmit coil of the plurality of transmit coils. The controller is also configured to select a transmit coil to use to transmit wireless power to a receive coil of a wireless power receiver responsive to the determined at least one of the resonant frequency and the Q-factor for each transmit coil of the plurality of transmit coils.

Foreign object detection for wireless power transmitters and related systems, methods, and devices are disclosed. A controller for a wireless power transmitter includes a processing core and an analog to digital converter configured to sample at least one of a coil voltage potential and a coil current of a transmit coil. The processing core is configured to determine an expected reference Q-factor value responsive to the at least one of the sampled coil voltage potential and the sampled coil current, and compare the expected reference Q-factor value to a reference Q-factor value received from a wireless power receiver. The processing core is further configured to determine that a foreign object is detected proximate to the transmit coil responsive to a comparison of the expected Q-factor value to the reference Q-factor value received from the wireless power receiver.

A method may include selecting, based on a condition of an electromagnetic load, a selected measurement technique from of a plurality of impedance measurement techniques for measuring an impedance of the electromagnetic load and performing the selected measurement technique to generate an estimate of the impedance of the electromagnetic load.

A measurement method for an aviation-specific inductive proximity sensor (IPS for short) includes steps of: 1) building a measurement circuit, wherein an IPS comprises an internal resistance r and an inductance L; 2) building a look-up table, wherein the step 2) specifically comprises steps of: sampling a first voltage measured value U.sub.1 corresponding to a first constant delay time T.sub.1 with the ADC; sampling a second voltage measured value U.sub.2 corresponding to a second constant delay time T.sub.2 with the ADC; then obtaining voltage discharge formulas U.sub.1(T.sub.1, R, r, L) and U.sub.2(T.sub.2, R, r, L) of an r-L circuit; and 3) compressing the look-up table, utilizing the compressed look-up table for calculation during measurement. The present invention ensures that the system works within a standard temperature range, and improves measurement stability, reliability, and real-time performance. Furthermore, there is no floating point calculation, which saves CPU or MCU hardware resources.

A current sensor circuit is provided. The circuit includes a voltage integration circuit connected in parallel to an inductive element. The voltage integration circuit is configured to integrate an inductive element current through the inductive element between a first potential at a first end of the inductive element and a second potential a second end of the inductive element. The voltage integration circuit provides a voltage analog of the inductive element current. A voltage current convertor circuit is electrically connected to the voltage integration circuit. The voltage current convertor circuit is configured to convert the voltage analog of the voltage integration circuit to an output current that is proportional to the inductive element current.

A wireless power transmission system has a wireless power receiving device with a wireless power receiving coil that is located on a charging surface of a wireless power transmitting device with a wireless power transmitting coil array. Control circuitry in the wireless power transmitting device may use inverter circuitry to supply alternating-current signals to coils in the coil array, thereby transmitting wireless power signals. The control circuitry may also be used to detect foreign objects on the coil array such as metallic objects without wireless power receiving coils. For example, control circuitry may use inductance measurements from the coils in the coil array to determine a probability value indicative of whether a foreign object is present on the charging surface. The control circuitry may compare the probability value to a threshold and take suitable action in response to the comparison.

An electronic determination device is configured for determining at least one characteristic parameter of an electric machine with P phases, P≥3, connected to an electric starter and including at least P-1 switching arms, each switching arm being connected to a respective phase of the electric machine. The determination device comprises a control module configured to control respective switching arm(s) to close and the other switching arm(s) to open, so as to generate a current injection on two phases of the electric machine; an acquisition module configured to acquire measurements of respective current(s) and voltage(s) for said two phases, further to the generation of the current injection; and a calculation module configured to calculate at least one characteristic parameter of the electric machine according to the respective current(s) and voltage(s) measurements.