Abstract: A power module has a substrate, a magnetic component disposed on the substrate, a plurality of power integrated circuits (ICs), and a heat spreader. The heat spreader and at least a part of the plurality of power ICs are disposed on a top surface of the substrate. The heat spreader is fixed on the substrate through a structural adhesive, covering top surfaces of the part of the plurality of power ICs on the top surface of the substrate, and is in contact with the top surfaces of the part of the plurality of power ICs on the top surface of the substrate through a thermal conductive adhesive. A difference between a height measured from a topmost surface of the magnetic component to the top surface of the substrate and a height measured from a topmost surface of the heat spreader to the top surface of the substrate is within 300 um.

Abstract: The disclosure includes an air quantity analyzer for use in underground coal mines, comprising an explosion-proof enclosure. According to some embodiments, the air quantity analyzer for use in underground coal mines comprises a gas pipeline inside of the explosion-proof enclosure, the gas pipeline coupled to a mechanical component selected from the group consisting of an air sampler, a gas pool, and combinations thereof, a detection device inside of the explosion-proof enclosure, the detection device having a vacuum pump, wherein the vacuum pump is coupled to the gas pipeline, and a central processor inside of the explosion-proof enclosure and electrically coupled to the vacuum pump of the detection device, the central processor electrically coupled to an electric component selected from the group consisting of a light source, a detector, a power conversion module, a display and alarm module, a data communication module, and combinations thereof.

Abstract: A driver and a control valve are provided. The control valve includes a valve body, a first valve core and a second valve core. The valve body provided with a valve cavity. A side wall of the valve body is provided with a plurality of communicating holes, and the communicating hole penetrates through the side wall of the valve body and is in communicate with the valve cavity. The first valve core is rotatably disposed at one end of the valve cavity, the first valve core is provided with a plurality of first passages and a plurality of second passages on a circumferential side of the first valve core. The second valve core is rotatably disposed at the other end of the valve cavity, and the second valve core is coaxially disposed with the first valve core, and the second valve core is coaxially disposed with the first valve core.

Abstract: A first device is logged in with a first user account. The first device displays an avatar of a second user account in a first user interface of the first device. In response to an interaction instruction triggered on the avatar of the second user account, the first device generates an interaction message according to a first field corresponding to the first user account, an action description field corresponding to the interaction instruction, and a second field corresponding to the second user account. The first device transmits the interaction message to a second device that is logged in with the second user account.

Abstract: A resonant converter has a primary resonant tank circuit and a secondary resonant tank circuit. An inverter circuit converts an input DC voltage received by the resonant converter at an input voltage node to a pulsating signal that is fed to the primary resonant tank circuit to generate a resonant tank current that flows through a primary winding of a transformer. The resonant tank current induces current in a secondary winding of the transformer. The induced current is rectified by a rectifier and the rectified signal is filtered to generate an output DC voltage at an output voltage node. The secondary resonant tank circuit is disposed between the secondary winding of the transformer and the output voltage node, and a tank node of the secondary resonant tank is connected to the primary resonant tank circuit through the inverter circuit.

Abstract: A resonant converter has a primary resonant tank circuit and a secondary resonant tank circuit. An inverter circuit converts an input DC voltage received by the resonant converter at an input voltage node to a pulsating signal that is fed to the primary resonant tank circuit to generate a resonant tank current that flows through a primary winding of a transformer. The resonant tank current induces current in a secondary winding of the transformer. The induced current is rectified by a rectifier and the rectified signal is filtered by an output capacitor to generate an output DC voltage at an output voltage node. The secondary resonant tank circuit is disposed between the input voltage node and the output voltage node to inject odd order harmonics of the operating frequency to the primary tank circuit to shape the resonant tank current.

Abstract: A method of preparing epoxypropane by direct epoxidation of propylene includes the steps of contacting a mixed gas consisting of a reaction feed gas and a diluent gas with a catalyst to carry out reaction under reaction conditions of propylene epoxidation to prepare epoxypropane. The reaction feed gas contains propylene, oxygen gas and hydrogen gas while at least a portion of the diluent gas is a gaseous olefin. Using gaseous olefin as at least a portion of the diluent gas to perform propylene epoxidation that can significantly extend service life of the catalyst, effectively reduce the used amount of diluent gas, and improve the reaction selectivity and propylene conversion rate.

Abstract: A hybrid DC-DC converter includes a converter circuit, a bridge circuit with a bridge path that includes a winding of a transformer, and another bridge circuit with a bridge path that includes another winding of the transformer. Current through the bridge path of the other bridge circuit flows through the converter circuit in one direction and bypasses the converter circuit in the other direction. The converter circuit can operate in buck, boost, or buck-boost mode.

Abstract: An LLC resonant converter including a transformer, a switching full-bridge circuit, a resonant circuit, and a bridge rectifier. The switching full-bridge circuit has a first pair of switches and a second pair of switches, with the first pair of switches being connected between a DC input voltage and a second end of a secondary winding of the transformer, the second pair of switches being connected between a DC input voltage and a first end of the secondary winding of the transformer.

Abstract: A gas-sensitive material, a preparation method therefore and an application thereof, and a gas sensor using the gas-sensitive material are provided. The gas-sensitive material is a carbon material-metal oxide composite nanomaterial formed by compounding a carbon material and metal oxides. The content of the carbon material is 0.5˜20 wt. % and the content of the metal oxides is 80˜99.5 wt. %; the metal oxides contain tungsten oxide and one or more selected from tin oxide, iron oxide, titanium oxide, copper oxide, molybdenum oxide, and zinc oxide; the metal oxides are formed on the carbon material in the form of nanowires, and the nanowires are tungsten oxide-doped nanowires. The gas-sensitive material has reduced resistance, is capable of responding to various gases at a reduced working temperature.

Abstract: An LLC resonant converter including a transformer, a switching full-bridge circuit, a resonant circuit, and a bridge rectifier. The switching full-bridge circuit has a first pair of switches and a second pair of switches, with the first pair of switches being connected between a DC input voltage and a second end of a secondary winding of the transformer, the second pair of switches being connected between a DC input voltage and a first end of the secondary winding of the transformer.

Abstract: An LLC resonant converter includes a transformer, a switching half-bridge circuit, a resonant circuit, and a full-bridge rectifier. Both the switching half-bridge circuit and the full-bridge rectifier are on the same side of the transformer. The switching half-bridge circuit has a pair of switches, with one of the switches being connected to the output voltage node of the converter.

Abstract: In one example, a planar omnidirectional wireless power transfer system includes high frequency power generator configured to generate a supply of high frequency oscillating power, a number of transmitter-side resonant tank circuits electrically coupled to the high frequency power generator, a planar coil arrangement including a number of coils arranged for omnidirectional power transfer to a device placed over the planar coil arrangement, and a controller configured to activate individual ones of the transmitter-side resonant tank circuits to wirelessly transmit power to the device. In one aspect, the controller can activate individual ones of the transmitter-side resonant tank circuits over time to generate an omnidirectional field distribution for wireless power transmission.

Abstract: A hybrid DC-DC converter includes a converter circuit, a bridge circuit with a bridge path that includes a winding of a transformer, and another bridge circuit with a bridge path that includes another winding of the transformer. Current through the bridge path of the other bridge circuit flows through the converter circuit in one direction and bypasses the converter circuit in the other direction. The converter circuit can operate in buck, boost, or buck-boost mode.

Abstract: Method for determining parameter of a passive impedance adapter applicable to VSC-HVDC, including: S1. obtaining VSC-HVDC impedance and VSC-HVDC impedance curve X(f) based on VSC-HVDC impedance; S2. estimating upper limit value of the main capacitor in the passive impedance adapter; S3. calculating adapter parameter curve Xadapter(f); S4. determining value of the main capacitor and varying value of the main resistor until min[X(f)?Xadapter(f)] is maximized; determining whether min[X(f)?Xadapter(f)]>k holds; S5. If min[X(f)?Xadapter(f)]>k does not hold, increasing the value of the main capacitor and performing steps S2-S4 until min[X(f)?Xadapter(f)]>k holds when the value of the main capacitor is within the range of the value of the main capacitor, storing the parameters in an available parameter set; S6. reducing the value of the main capacitor, and storing the parameters when min[X(f)?Xadapter(f)]>k holds in the available parameter set; S7.

Abstract: In one example, an omnidirectional wireless power transfer system includes high frequency power generator configured to generate a supply of high frequency oscillating power, a number of transmitter-side resonant tank circuits electrically coupled to the high frequency power generator, a receptacle including a number of coils arranged for omnidirectional power transfer to an electronic device placed in the receptacle, and a controller configured to activate individual ones of the transmitter-side resonant tank circuits to wirelessly transmit power to the electronic device through near-field resonant inductive coupling. In one example, the receptacle can be embodied as a bowl, and the controller can activate individual ones of the transmitter-side resonant tank circuits over time to generate an omnidirectional field distribution for wireless power transmission. In other aspects, various transmitter-side and receiver-side tank circuits for coupling independent resonance and ZVS operation are described.

Abstract: The present invention relates to a self-alarm multi-stage complex screen filter for micro-irrigation and the assembly method thereof. The filter comprises a housing, an alarm, a multi-stage screen filtering element, and a segmented brush. The housing comprises a left housing, a middle housing, and a right housing. The multi-stage screen filtering element comprises a plurality of screen filter cylinders. The segmented brush comprises a plurality of bristle frames, a plurality of connecting rods, a connector and a power device. The middle housing is provided with a water inlet. The left housing is provided with a discharge pipe. The installation, disassembly, repair, maintenance of the filter of the present invention can be done more conveniently.

Abstract: An electronic candle may include a main candle body, a signal processing module, a candle flame piece, a lighting unit to light up the candle flame piece and an air flow detecting unit, wherein the candle flame piece extends from a through hole from an inner portion of the main candle body to an outer portion thereof, and edges of the candle flame piece axially shrinks towards a center portion of the candle flame piece; the lighting unit is disposed below the candle flame piece to light up the candle flame piece; the air flow detecting unit is disposed at an inner portion of the electronic candle, and the air flow detecting unit and the lighting unit are both connected to the signal processing module.

Abstract: The present invention relates to a self-alarm multi-stage complex screen filter for micro-irrigation and the assembly method thereof. The filter comprises a housing, an alarm, a multi-stage screen filtering element, and a segmented brush. The housing comprises a left housing, a middle housing, and a right housing. The multi-stage screen filtering element comprises a plurality of screen filter cylinders. The segmented brush comprises a plurality of bristle frames, a plurality of connecting rods, a connector and a power device. The middle housing is provided with a water inlet. The left housing is provided with a discharge pipe. The installation, disassembly, repair, maintenance of the filter of the present invention can be done more conveniently.

Abstract: In one example, an omnidirectional wireless power transfer system includes high frequency power generator configured to generate a supply of high frequency oscillating power, a number of transmitter-side resonant tank circuits electrically coupled to the high frequency power generator, a receptacle including a number of coils arranged for omnidirectional power transfer to an electronic device placed in the receptacle, and a controller configured to activate individual ones of the transmitter-side resonant tank circuits to wirelessly transmit power to the electronic device through near-field resonant inductive coupling. In one example, the receptacle can be embodied as a bowl, and the controller can activate individual ones of the transmitter-side resonant tank circuits over time to generate an omnidirectional field distribution for wireless power transmission. In other aspects, various transmitter-side and receiver-side tank circuits for coupling independent resonance and ZVS operation are described.