A filter circuit comprising a first feedback circuit configured to: receive a sensed-voltage-level-signal representative of a sensed voltage across a current sensing element; receive a voltage-set-point-signal; and set a regulation-control-signal for a current regulation device such that the sensed-voltage-level-signal tends towards the voltage-set-point-signal. The filter circuit also comprises a second feedback circuit configured to: receive a predetermined-threshold-signal; and receive a regulation-control-voltage-signal, representative of a voltage level of the regulation-control-signal. The second feedback circuit is configured to adjust the voltage-set-point-signal in accordance with a comparison between the regulation-control-voltage-signal and the predetermined-threshold-signal.

A power converter installed in a refrigeration cycle applied equipment includes a rectifier configured to rectify a first alternating-current power supplied from a commercial power supply, a capacitor connected to output ends of the rectifier, an inverter configured to convert power output from the rectifier and the capacitor into a second alternating-current power and to output the second alternating-current power to a motor, and a controller configured to control an operation of the inverter such that the second alternating-current power containing pulsation according to pulsation of power flowing into the capacitor from the rectifier is output from the inverter and to reduce current flowing to the capacitor. The power converter is configured to operate such that the pulsation width of the pulsating current generated by the second alternating-current power is different depending on whether an operation of the refrigeration cycle applied equipment is a cooling operation or a heating operation.

A modular multilevel AC-AC converter is provided which allows for the direct conversion of AC power between different voltage levels using half-bridge submodules. The converter has a partial power processing topology that exploits internal circulating DC currents to facilitate charge balance of submodule capacitors. This power transfer mechanism eliminates the centralized DC link required in conventional back-to-back modular multilevel converter (B2B-MMC) systems, thus enabling reductions in the semiconductor effort and submodule capacitor energy storage requirements typically required in a B2B-MMC solution. A modulation scheme is also provided for different AC voltage conversion ratios. The converter operation and controls are validated by simulation, and experimentation.

A power converting apparatus includes a rectifier unit that rectifies a supply voltage applied from a commercial power supply, a capacitor connected to an output end of the rectifier unit, an inverter that converts direct-current power output from the capacitor into alternating-current power and outputs the alternating-current power to a device including a motor, current detection units that detect a power state of the capacitor, and a control unit that performs, by controlling the inverter, load pulsation compensation and power-supply pulsation compensation and adjusts a degree of at least one of the load pulsation compensation and the power-supply pulsation compensation on a basis of detection values of the current detection units. The load pulsation compensation is performed to compensate a load pulsation in a load unit including the inverter and the device. The power-supply pulsation compensation is performed to compensate a power-supply pulsation in the load unit.

A power conversion device and a control circuit are provided. The power conversion device includes a power conversion circuit and a control circuit. The control circuit includes a first controller and a second controller. The power conversion circuit includes an input capacitor, a rectifier circuit, and a power switch. The input capacitor is coupled to an input terminal of the power conversion device. The rectifier circuit converts an input AC power into a rectified power. The first controller operates the power switch to cause the power conversion circuit to convert the rectified power into an output power. The second controller detects a signal waveform at the input terminal, and controls the first controller in response to the signal waveform at the input terminal, so as to utilize the power switch to discharge the charge stored in the input capacitor.

Synchronous rectifier circuit topologies for a wireless power receiver receiving a supply of power from a wireless transmitter are disclosed. The synchronous rectifier circuit topologies include a half-bridge diode-FET transistor rectifier for rectifying the wireless power into power including a DC waveform, using a control scheme that may be provided by a delay-locked loop clock, or phase shifters, or wavelength links to control conduction of FET transistors in the synchronous rectifier circuit topology, and maintaining a constant switching frequency to have the diodes, coupled to FET transistors, to allow current to flow through each one respectively at the appropriate timing, focusing on high conduction times. The synchronous rectifier circuit topologies may enable power transfer of high-frequency signals at enhanced efficiency due to significant reduction of forward voltage drop and lossless switching.

An electrical power conversion system for converting a high voltage from a HV electrical power supply to a low voltage is disclosed. In an embodiment, the electrical power conversion system includes at least one power converter and at least one RC network including a plurality of resistive components and a plurality of capacitive components electrically connected in series. In an embodiment, the at least one RC network is in series connection with the at least one power converter and the at least one RC network and at least one power converter are arranged to be connected across a line potential of the HV electrical power supply.

A low voltage AC power controller uses a line coupled capacitor AC to DC converter circuit to obtain energy from AC line power supplied to an AC load and may be used with an external high voltage AC switching device to control power supplied to the AC load. The line coupled capacitor AC to DC converter circuit provides a low power device that senses characteristics of the power supplied to the load and can communicate sensed information and/or receive control information related to the power supplied to the load.

A capacitive power supply device for a control device of an electrical switching apparatus, including a power supply module that has two input terminals and a power supply voltage between the two terminals, and suitable for supplying a power supply current to a control member suitable for controlling the electrical switching apparatus when the power supply voltage is below a predetermined actuation threshold, the power supply module including a first capacitor connected at the input of voltage rectifying means, the control member being connected at the output of a rectifying block, wherein a second capacitor and a first switch, suitable for connecting the second capacitor based on a comparison of the power supply voltage to a capacitor switching threshold value.

The invention relates to photoluminescent signs, in particular to signs in which one or more light emitting diodes (LEDs) emit light that excites one or more photoluminescent (PL) elements. In one aspect, a sign may include one or more photoluminescent elements; one or more light emitting diodes (LEDs) arranged to excite the one or more photoluminescent elements; and circuitry arranged for connection to an AC power supply and supplying power to the LEDs.