The disclosure relates to accurately determining a DC energy signal, such as a DC current or DC voltage, which may be particularly useful when controlling a formation/testing current of a battery cell during formation and/or testing. In the battery formation/testing context, a current sensor is used to measure the current of the battery cell, which is used as a feedback signal for controlling the current to achieve a target current. The transfer function of the current sensor is used to improve the accuracy of the current measurement. Because the transfer function can be regularly determined during formation/testing, a lower-cost current sensor with relatively poor temperature coefficient may be used. Any change in the gain of the current sensor may be detected by the transfer function determination and corrected for. Therefore, high current control accuracy may be achieved at lower cost.

A system includes a switch network coupled to a power source, wherein the switch network comprises a plurality of power switches, a transmitter resonant tank coupled to the plurality of power switches, wherein the transmitter resonant tank comprises a first variable capacitance network, a transmitter coil coupled to the transmitter resonant tank, and a first receiver comprising a first receiver coil configured to be magnetically coupled to the transmitter coil, and a first receiver resonant tank coupled to the first receiver coil, wherein the first receiver resonant tank comprises a second variable capacitance network.

A device for detecting a drop in voltage of an AC supply delivering electrical energy to an energy converter in order to supply electrical equipment, the device being connected to an electrical energy reserve for supplying the energy converter. The device includes a full-wave rectifier for rectifying the AC supply, a comparator that compares a first predetermined voltage with a full-wave rectified voltage, a circuit for charging a capacitor in order to charge the capacitor when the rectified voltage is below the predetermined threshold, a circuit for discharging the capacitor in order to discharge the capacitor when the rectified voltage is above the predetermined threshold, a comparator for comparing the voltage at the terminals of the capacitor with a second predetermined voltage, and a circuit for controlling the reserve of electrical energy.

In an embodiment, a current sensor unit includes: a rectification module, to convert an AC current to a pulsed DC current; a conversion module containing an energy storage element, to store energy based upon the pulsed DC current during a charging mode and to generate a power supply current based upon a voltage of the energy storage element; a mode switching module, bypassed by the conversion module during operation in the charging mode, and bypassing the conversion module during operation in an energy release mode; a current sensor module, to detect a pulsed DC current flowing back from the conversion module or mode switching module; a control module, to acquire electrical energy from the power supply current, determine that operation is in the charging mode or energy release mode based upon the voltage of the energy storage element, and acquire a detection value provided by the current sensor module.

A sensor assembly system and method for providing good voltage accuracy for monitoring a three phase high voltage power line without connecting to ground. The sensor assembly system comprises three sensor assemblies having reference point ends not connected to ground. All three sensor assemblies are connected together at the reference point ends to create a neutral common reference point not connected to ground potential that is at zero volts when all of the three phases are at the same line voltage.

A sensor assembly system and method for providing good voltage accuracy for monitoring a three phase high voltage power line without connecting to ground. The sensor assembly system comprises three sensor assemblies having reference point ends not connected to ground. All three sensor assemblies are connected together at the reference point ends to create a neutral common reference point not connected to ground potential that is at zero volts when all of the three phases are at the same line voltage.

A cell management module for a power supply module including a plurality of power cells includes at least one cell-sensing circuit and a current measurement circuit connected to the at least one cell-sensing circuit. The at least one cell-sensing circuit includes a transformer having a first winding and a second winding inductively coupled to the first winding. A first sub-circuit of the cell-sensing circuit includes the first winding of the transformer and is operable to selectively pulse a first signal through the first winding. A second sub-circuit of the cell-sensing circuit includes the second winding of the transformer and one of the power cells of the power supply module. The current measurement circuit is connected to the first sub-circuit of the at least one cell-sensing circuit and infers a voltage of the power cell based on a measured current of the first signal.

A cell management module for a power supply module including a plurality of power cells includes at least one cell-sensing circuit and a current measurement circuit connected to the at least one cell-sensing circuit. The at least one cell-sensing circuit includes a transformer having a first winding and a second winding inductively coupled to the first winding. A first sub-circuit of the cell-sensing circuit includes the first winding of the transformer and is operable to selectively pulse a first signal through the first winding. A second sub-circuit of the cell-sensing circuit includes the second winding of the transformer and one of the power cells of the power supply module. The current measurement circuit is connected to the first sub-circuit of the at least one cell-sensing circuit and infers a voltage of the power cell based on a measured current of the first signal.

A sensor assembly system and method for providing good voltage accuracy for monitoring a three phase high voltage power line without connecting to ground. The sensor assembly system comprises three sensor assemblies having reference point ends not connected to ground. All three sensor assemblies are connected together at the reference point ends to create a neutral common reference point not connected to ground potential that is at zero volts when all of the three phases are at the same line voltage.

A sensor assembly system and method for providing good voltage accuracy for monitoring a three phase high voltage power line without connecting to ground. The sensor assembly system comprises three sensor assemblies having reference point ends not connected to ground. All three sensor assemblies are connected together at the reference point ends to create a neutral common reference point not connected to ground potential that is at zero volts when all of the three phases are at the same line voltage.