Spatially resolved Fourier Transform Impedance Spectroscopy (FTIS) is disclosed to spatially map and quickly build the frequency response of optoelectronic devices using optical probes. The transfer function of a linear system is the Fourier transform of its impulse response, which may be obtained from transient photocurrent measurements of devices such as photodetectors and solar cells. We apply FTIS to a PbS colloidal quantum dot (QD)/SiC heterojunction photodiode and corroborate results using intensity-modulated photocurrent spectroscopy. The cutoff frequencies of the QD/SiC devices were as high as ˜10 kHz, demonstrating their utility in advanced flexible and thin film electronics. The practical frequencies for FTIS lie in the mHz-kHz range, ideal for composite or novel materials such as QD films that are dominated by interfacial trap states.

A power monitor includes a detecting circuit, a processing circuit, and a warning circuit. The detecting circuit detects a first abnormal condition of a primary side circuit and a second abnormal condition of a secondary side circuit. The processing circuit calculates a first class and a first occurring number of the first abnormal condition, and calculates a second class and a second occurring number of the second abnormal condition. The processing circuit determines whether the first occurring number is larger than a first predetermined number corresponding to the first class; if it is, the processing circuit outputs a first abnormal signal. The processing circuit determines whether the second occurring number is larger than a second predetermined number corresponding to the second class; if it is, the processing circuit outputs a second abnormal signal. The warning circuit outputs a warning signal according to the first or the second abnormal signal.

A method and apparatus are for monitoring a secondary power device and for accurately checking a state of the secondary power device, and an electronic system includes the apparatus. The method of monitoring a secondary power device includes setting a first reference parameter by using a voltage of at least one capacitor of the secondary power device, setting a second reference parameter by using the voltage of the at least one capacitor and the first reference parameter, and setting a reference level for checking of the state of the secondary power device by using the second reference parameter, wherein the reference level is used in checking of the state of the secondary power device.

A device includes a load test unit that determines whether to permit startup of the device using power of a battery supplying power to the device, and a control unit that starts up the device in a case where it is determined to permit startup of the device using the battery and a first voltage is requested of a power supply apparatus to restrict power received from the power supply apparatus. The control unit cancels the restriction of the received power in a case where a notification of completion of connection is received from the power supply apparatus, after the device is started up and a second voltage is requested of the power supply apparatus.

A device includes a load test unit that determines whether to permit startup of the device using power of a battery supplying power to the device, and a control unit that starts up the device in a case where it is determined to permit startup of the device using the battery and a first voltage is requested of a power supply apparatus to restrict power received from the power supply apparatus. The control unit cancels the restriction of the received power in a case where a notification of completion of connection is received from the power supply apparatus, after the device is started up and a second voltage is requested of the power supply apparatus.

Systems, methods, and devices are provided for identifying multiple faults across multiple phases of a multi-phase and/or multi-section capacitor bank. A protection device may measure various voltages and currents within the capacitor bank. A phase angle of the measured voltages and currents may be used to determine a location of the faults therein. For example, a phase angle of a compensated unbalance voltage may be compared to a phase angle of a positive-sequence voltage of the capacitor bank. A logic controller may use a difference between the phase angle of the compensated unbalance voltage and the phase angle of the positive-sequence voltage to determine a location (e.g., a phase and/or a section of the capacitor bank) of the faults in the capacitor bank.

Systems, methods, and devices are provided for identifying multiple faults across multiple phases of a multi-phase and/or multi-section capacitor bank. A protection device may measure various voltages and currents within the capacitor bank. A phase angle of the measured voltages and currents may be used to determine a location of the faults therein. For example, a phase angle of a compensated unbalance voltage may be compared to a phase angle of a positive-sequence voltage of the capacitor bank. A logic controller may use a difference between the phase angle of the compensated unbalance voltage and the phase angle of the positive-sequence voltage to determine a location (e.g., a phase and/or a section of the capacitor bank) of the faults in the capacitor bank.

The invention relates to a device and a method for monitoring a DC link capacitor (C.sub.ZK) in an electrical DC link of a circuit (1) operated on a mains voltage V.sub.ac, the circuit comprising a power factor correction filter (PFC) and an inverter (20), the DC link capacitor (C.sub.ZK) to be monitored being between the power factor correction filter (PFC) and the inverter (20). During the operation of the circuit (1), the DC link capacitance C of the DC link capacitor (C.sub.ZK) is determined at least at certain time intervals over the operating time by measuring a power ripple W of a DC link voltage V.sub.ZK, which DC link voltage arises at the DC link capacitor (C.sub.ZK), said power ripple pulsing at twice the frequency of the mains voltage, and the remaining service life or the service life end and/or usability end of the DC link capacitor (C.sub.ZK) is determined, by means of an evaluation circuit (30), from the DC link capacitance C determined in this way.

An apparatus such as a power supply includes management hardware. The management hardware monitors operation of multiple power converter phases coupled in parallel to produce an output voltage. Based on the monitored operation, the management hardware determines a status of a series circuit path connecting windings of the multiple power converter phases. The management hardware produces status information indicating the status of the series circuit path.

An apparatus such as a power supply includes management hardware. The management hardware monitors operation of multiple power converter phases coupled in parallel to produce an output voltage. Based on the monitored operation, the management hardware determines a status of a series circuit path connecting windings of the multiple power converter phases. The management hardware produces status information indicating the status of the series circuit path.