A method for estimating resistances of a circuit having a plurality of resistances comprising a first resistance and a second resistance may include applying a first bias voltage across the circuit and measuring a first voltage at a common node between the first resistance and the second resistance in order to determine a mathematical relationship between the first resistance and the second resistance, applying a second bias voltage across the circuit and a third resistance in parallel with the circuit and measuring a second voltage at the common node between the first resistance and the second resistance in order to determine a mathematical relationship between the third resistance and at least one of the first resistance and the second resistance, and based on at least the measurement of the first voltage and the measurement of the second voltage, determining the first resistance and the second resistance as a function of the third resistance.

A method for estimating resistances of a circuit having a plurality of resistances comprising a first resistance and a second resistance may include applying a first bias voltage across the circuit and measuring a first voltage at a common node between the first resistance and the second resistance in order to determine a mathematical relationship between the first resistance and the second resistance, applying a second bias voltage across the circuit and a third resistance in parallel with the circuit and measuring a second voltage at the common node between the first resistance and the second resistance in order to determine a mathematical relationship between the third resistance and at least one of the first resistance and the second resistance, and based on at least the measurement of the first voltage and the measurement of the second voltage, determining the first resistance and the second resistance as a function of the third resistance.

An earth fault detection apparatus includes a switch group configured to switch between a first measurement path including a battery and a capacitor, and a second and third measurement paths including the battery, a positive/negative-side insulation resistance, and the capacitor; a reference resistance and a test switch; and a control unit calculating a first reference value based on each charging voltage in a case where the test switch is opened and the capacitor is charged, and calculating the insulation resistance with reference to a conversion map created to correspond to an electrostatic capacitance between a power supply line and ground, wherein the control unit calculates a second reference value based on each charging voltage in a case where the test switch is closed and the capacitor is charged for a shorter time, and estimates the electrostatic capacitance with reference to a predetermined test conversion map.

An electronic device may include one or more terminals configured to provide a voltage signal to an actuator. The electronic device may detect a current associated with the voltage signal provided by the terminal to the actuator. The electronic device may determine an impedance across associated with the actuator based on the voltage signal and the electrical current. The electronic device may compare the impedance to a threshold impedance to determine whether there is sufficient skin contact with the actuator. The electronic device may provide audio via cartilage conduction if there is sufficient contact based on comparing the impedance to the threshold impedance, or may output a notification to the user to adjust placement of the electronic device to improve contact.

An electronic device may include one or more terminals configured to provide a voltage signal to an actuator. The electronic device may detect a current associated with the voltage signal provided by the terminal to the actuator. The electronic device may determine an impedance across associated with the actuator based on the voltage signal and the electrical current. The electronic device may compare the impedance to a threshold impedance to determine whether there is sufficient skin contact with the actuator. The electronic device may provide audio via cartilage conduction if there is sufficient contact based on comparing the impedance to the threshold impedance, or may output a notification to the user to adjust placement of the electronic device to improve contact.

The present disclosure provides a device and methods for determining the original stratum direction of a core. The device includes a confining pressure pump, a resistance meter, and a core holder composed of upper and lower portions. The present disclosure further provides three methods for determining the original stratum direction of the core. The three methods respectively use the device to measure resistance values at different positions of the core, and compare a test result with an imaging result of resistivity imaging logging data to determine the rock direction of the core in a stratum.

Systems and methods relating to bio-impedance analysis. The system eliminates the need for hardware phase measurements by using the K-K transform to extract the phase from the magnitude detected. The system has a magnitude detection sub-system that includes a signal generation block, a DC cancellation block, and an amplitude control block. An A/D converter converts the detected magnitude into a digital signal and signal processing is performed to extract the phase of the signal from the magnitude detected.

The present disclosure provides an inductance detection method includes steps of: (a) acquiring a stator resistance of the reluctance motor; (b) injecting a high-frequency sinusoidal signal in the d-axis or q-axis direction; (c) injecting an align signal command in the q-axis or d-axis direction; (d) receiving a dq-axes signal generated through injecting the high-frequency sinusoidal signal and the align signal command; (e) sampling a motor feedback signal generated through receiving the dq-axes signal; (f) in the direction of injecting the high-frequency sinusoidal signal, calculating an amplitude difference between the high-frequency sinusoidal signal and the motor feedback signal, and adjusting an amplitude of the high-frequency sinusoidal signal according to the amplitude difference for regulating a feedback amplitude of the motor feedback signal; and (g) when the feedback amplitude reaching an expected amplitude, calculating an apparent inductance of the reluctance motor based on the dq-axes signal, the motor feedback signal and the stator resistance.

The present disclosure provides an inductance detection method includes steps of: (a) acquiring a stator resistance of the reluctance motor; (b) injecting a high-frequency sinusoidal signal in the d-axis or q-axis direction; (c) injecting an align signal command in the q-axis or d-axis direction; (d) receiving a dq-axes signal generated through injecting the high-frequency sinusoidal signal and the align signal command; (e) sampling a motor feedback signal generated through receiving the dq-axes signal; (f) in the direction of injecting the high-frequency sinusoidal signal, calculating an amplitude difference between the high-frequency sinusoidal signal and the motor feedback signal, and adjusting an amplitude of the high-frequency sinusoidal signal according to the amplitude difference for regulating a feedback amplitude of the motor feedback signal; and (g) when the feedback amplitude reaching an expected amplitude, calculating an apparent inductance of the reluctance motor based on the dq-axes signal, the motor feedback signal and the stator resistance.

A shutdown method applicable to a terminal having a rechargeable battery, the method includes: determining a first impedance and a second impedance of the rechargeable battery, wherein the first impedance is an impedance determined based on a current temperature of the rechargeable battery, and the second impedance is an impedance determined based on a current number of charge times of the rechargeable battery; determining a target impedance as a larger impedance value from the first impedance and the second impedance; determining a shutdown voltage of the terminal based on a preset open circuit voltage of the rechargeable battery, the target impedance and a current operating current of a charging circuit; and controlling the terminal to shut down, when an operating voltage of the rechargeable battery is decreased to the shutdown voltage.