A method of establishing current limits for each of a plurality of device couplers mounted on a trunk of an electrical circuit at distributed physical positions, in which each of said device couplers is capable of servicing one or more spurs connected thereto, and in which said trunk has a total trunk current and a known resistive component, comprising the steps of: a) establishing physical characteristics of the electrical circuit including i) an order in which said device couplers are mounted on said trunk along its length; ii) a load current each device coupler requires to service the one or more spurs connected thereto; and, iii) a voltage drop of each of said sections of trunk caused by the resistive component thereof, which is proportional to a physical length thereof and the combined load currents of each device coupler serviced by that section of trunk; b) calculating a current limit for each device coupler, which current limit is greater than said load current, according to a predetermined tolerance rationale; c) calculating an intermediate trunk current available to each device coupler by deducting from said total trunk current the current limits of each device coupler preceding that device coupler in said order, as well as a consequential reduction in current caused by said voltage drop of each of said sections of trunk preceding that device coupler; and, d) adjusting said current limits so none exceeds the intermediate trunk current available to the corresponding device coupler.

For operating multi-axis drive assemblies more reliably even in a field weakening range, a current conversion device is proposed which includes a voltage-source DC link, a plurality of inverters having each a DC input side connected to the voltage-source DC link and AC output-side terminals for connection to an electric motor, and a control device configured to short-circuit each of the inverters. A measurement device measures an electrical variable at each of the inverters. The control device determines based on the measured electrical variables independently for each of the inverters directly or indirectly whether a particular inverter is feeding energy into the voltage-source DC link, and short-circuits, when this is the case, the particular inverter independently of the other inverters. A corresponding operating method is also disclosed.

A cable drop compensation circuit includes a current detection circuit, a compensation judgment circuit, and a compensation circuit. The current detection circuit detects a load current supplied to a load by a DC output circuit, so as to generate a current detection signal. The compensation judgment circuit receives the current detection signal, and generates a judgment signal when judging the load current higher than a predetermined compensation value. When receiving the judgment signal, the compensation circuit generates a compensation signal. In response to the compensation signal, the DC output circuit raises an output voltage by a compensation voltage.

A cable drop compensation circuit includes a current detection circuit, a compensation judgment circuit, and a compensation circuit. The current detection circuit detects a load current supplied to a load by a DC output circuit, so as to generate a current detection signal. The compensation judgment circuit receives the current detection signal, and generates a judgment signal when judging the load current higher than a predetermined compensation value. When receiving the judgment signal, the compensation circuit generates a compensation signal. In response to the compensation signal, the DC output circuit raises an output voltage by a compensation voltage.

A power line interface is electrically connectable to a direct-current power system including a power line. A bidirectional DC-DC converter is electrically connected to the power line interface and a battery. A controller receives a first current value measured by a first current sensor and a current command value and performs constant current control processing that controls the bidirectional DC-DC converter so that the first current value equals the current command value. The controller receives a first voltage value measured by a voltage sensor and a voltage command value and performs constant voltage control processing that controls the bidirectional DC-DC converter so that the first voltage value equals the voltage command value. The controller switches operation from the constant current control processing to the constant voltage control processing.

Embodiments of the subject invention are drawn to power supply units and systems for supplying power to loads. Specific embodiments relate to systems incorporating the loads. The power supply units and systems can include a feedback mechanism for monitoring the system and maintaining a parameter of interest at or near a desired value (e.g., for maintaining the frequency of operation at or near resonance). The feedback mechanism is configured such that, if the at least one parameter indicates that the frequency of operation is away from a resonant frequency of the power amplifier, the feedback mechanism adjusts the frequency of operation closer to the resonant frequency of the power amplifier. The at least one load can have a variable impedance, though embodiments are not limited thereto.

A device is provided for intrinsically safe redundant current supply of field devices with a common current-limiting resistor in the mesh of the field device and with redundant current supply units. A current sensor can be provided in the mesh of the field device, the output signal of which sensor is connected to devices for controlling current or active current limiting in the redundant current supply units.

A device is provided for intrinsically safe redundant current supply of field devices with a common current-limiting resistor in the mesh of the field device and with redundant current supply units. A current sensor can be provided in the mesh of the field device, the output signal of which sensor is connected to devices for controlling current or active current limiting in the redundant current supply units.

A power adapter and a method of adapting power for electronic devices. Two or more input ports are connectable to electrical power sources. An output port is connectable to an electronic device. A controller is in parallel power-receiving communication with the input ports, in power-providing communication with the output port, and in data-carrying communication between the output port and a first one of the input ports. The method includes checking for electrical power at the first input port and at least one other input port, and when electrical power is present at both, coupling the power from the input ports in parallel to the output port and enabling data communication between the first input port and the output port.

A power adapter and a method of adapting power for electronic devices. Two or more input ports are connectable to electrical power sources. An output port is connectable to an electronic device. A controller is in parallel power-receiving communication with the input ports, in power-providing communication with the output port, and in data-carrying communication between the output port and a first one of the input ports. The method includes checking for electrical power at the first input port and at least one other input port, and when electrical power is present at both, coupling the power from the input ports in parallel to the output port and enabling data communication between the first input port and the output port.