A harmonic harvesting circuit design for harvesting un-rectified AC power contained in the fundamental and harmonic frequencies at the output of conventional rectifying circuits.

An AC-DC converter, power supply board and display apparatus is disclosed. The AC-DC converter comprises: an AC-DC converting circuit; a transformer, whose primary coil has a first terminal coupled to a positive output terminal of the AC-DC converting circuit, and second terminal connected to a load; a voltage monitoring circuit, whose input terminal is coupled to the first terminal of the secondary coil, and second terminal of the secondary coil connected to a ground; and a control circuit, whose input terminal is coupled to an output terminal of the voltage monitoring circuit, and output terminal coupled to the AC-DC converting circuit; wherein the voltage monitoring circuit outputs a control voltage when a voltage outputted by the first terminal of the secondary coil of the transformer exceeds a first threshold; the control circuit controls the AC-DC converting circuit to stop providing power supply when the control voltage exceeds a second threshold.

A power conditioning unit used in an electrical system. The power conditioning unit includes a positive bus and a negative bus that are electrically connected to a direct current load to enable supplying direct current electrical power to the direct current load; and a first phase leg, which includes a first diode electrically connected to the positive bus, a first transistor electrically connected to the negative bus, and a first node between the first diode and the first transistor. The first node is electrically connected to an alternating current power source to enable the first phase leg to receive a first phase of alternating current electrical power from the alternating current power source and the first transistor opens and closes to control flow of the first phase through the first phase leg to facilitate generating the direct current electrical power at a target voltage using the alternating current electrical power.

An inverter device uses an inverter to convert DC voltage supplied from a rectifying component to AC voltage and applies the AC voltage to an inductive load. The inverter device includes a shunt resistor provided on a direct-current link interconnecting the rectifying component and the inverter, a first terminal passing current to the shunt resistor, a second terminal to which the current from the shunt resistor flows, and a printed board having a conductive pattern with first and second conductive pattern components joining the shunt resistor and the first and second terminals, respectively. The first conductive pattern component includes a first central region connecting right and left side ends of the shunt resistor to right and left side ends of the first terminal, and first right and left side protruding regions. A ratio of areas of the first left and right side protruding regions is 0.6 to 1.6.

Systems and methods for monitoring the performance of reciprocating compressors are disclosed. The monitoring system includes inductive power generation at individual cylinders of the compressor, alleviating the need to run power supply and conduits to each of the cylinders. The inductive system also allows piston position to be determined at each cylinder. Data acquired at each cylinder can be telemetered to a central hub for processing.

An exemplary method of receiving wireless power from a wireless power transmitter includes, at a wireless power receiver having a controller, an antenna, a rectifier coupled with the antenna, and a boost converter coupled with the rectifier: (i) rectifying, by the rectifier, energy from wireless power transmission waves received by the antenna into a first voltage, (ii) increasing, by the boost converter, the first voltage to a second voltage based on instructions from the controller, and (iii) controlling, by the controller, an amount of increase in voltage from the first voltage to the second voltage based on a comparison.

An uninterruptible power supply circuit is provided. The uninterruptible power supply circuit includes a first diode, a second diode, a bridge rectifier, and one or more electrical loads. The first diode, the second diode, the bridge rectifier, and the one or more electrical loads are electrically connected in the uninterruptible power supply circuit to drive the one or more electrical loads with a DC voltage or the intended AC supply voltage when the AC supply voltage is cutoff.

A direct-current power supply device includes a reactor, one end of which is connected to one output end of an alternating-current power supply, a switching unit for short-circuiting the other end of the reactor and the other output end of the alternating-current power supply, a rectifying unit configured to rectify an alternating-current voltage supplied from the alternating-current power supply and generate a voltage equal to or higher than a double voltage, a smoothing capacitor connected to the rectifying unit via backflow preventing diodes and configured to smooth a direct-current voltage output from the rectifying unit, and a control unit configured to control the switching unit and stop the supply of the alternating-current voltage to the rectifying unit in a predetermined period after a predetermined time has elapsed from a zero cross point of the alternating-current voltage output from the alternating-current power supply.

An improved control arrangement is used in a high power rectifier and comprises two or more power controllers ganged together in parallel. Each power controller rectifies an AC voltage signal using zero voltage crossing switching to produce a binary switched signal and each power controller is connected to an independent connectable load. Each power controller includes a fast acting binary power switch that selectively connects the respective independent connectable load to the rectified AC voltage signal. The control arrangement selectively activates the power controllers to define a desired connected load. This high power rectifier and control arrangement is advantageously used to provide fast up down power regulation to a grid by selective storage of thermal energy and deriving power from the thermal energy storage system to add fill in power to the grid.

A power converter in a powered device (PD) of Power-over-Ethernet (PoE) system and a control method are provided. The power converter includes a transformer, a PD interface, a primary-side controller and a detecting circuit. The PD interface receives an input voltage to determine a PoE protocol type of the input voltage, so as to generate a first power type signal. The primary-side controller receives the first power type signal to adjust a primary-side control signal, wherein a primary-side switch is controlled by the primary-side control signal. The detecting circuit detects a mapping signal generated in a secondary-side winding according to the primary-side control signal to generate a second power type signal, wherein the second power type signal indicates the PoE protocol type of the input voltage.