Abstract: A power factor correction circuit can include: a power meter configured to measure a power factor at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust the power factor of an input AC power; an EMI filter disposed between the switching-type regulator and the input port; and a controller configured to generate the switching control signal to maximize the power factor by adjusting a current reference signal according to a measured power factor, where the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: A power factor correction circuit can include: a power meter configured to measure THD at an input port; a switching-type regulator that is controllable by a switching control signal in order to adjust a power factor of an input signal thereof; and a controller configured to generate the switching control signal to control the switching-type regulator to perform power factor correction, where the controller minimizes the THD by adjusting a current reference signal according to a measured THD, and the current reference signal represents an expected inductor current of the switching-type regulator.

Abstract: The invention provides methods and compositions for recovering oil from stillage. The method comprises the addition of a surfactant and a microparticle comprising hydrophilic silica to a grain to ethanol stillage. The methods and compositions of the present invention release oil trapped in solid aggregates, increasing the total amount of oil extracted from the stillage.

Abstract: A cationic polymer salt composition is provided that includes a reaction product derived from reaction of a polyamine or a polyalkyleneimine and a substituted alkyl trialkyl quaternary ammonium salt. Also provided are surfactant compositions. The compositions may also include carriers, such as water, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, monoethyleneglycol, an ethyleneglycol monobutyl ether, and hexylene glycol.

Abstract: Disclosed an LED drive circuit, which is configured to switch the connection of a plurality of LED loads between parallel connection and series connection. When an input voltage is low, the LED loads are controlled to be in parallel connection, and the transistors provided on corresponding parallel branch circuits are controlled to operate in a linear state for regulating the current flowing through the parallel branch circuits. When the input voltage increases, the LED loads or LED drive modules are controlled to be in series connection, and the transistors provided on the series branch circuits are controlled to regulate the current flowing through all the LED loads. Accordingly, on one hand, all the LED loads have a same operating time, on the other hand, all the LED loads operate during most time of every operating cycle, which improves the lifetime of the circuit and the utilization of the LED loads.

Abstract: A method of detecting a state of charge of a battery, can include: obtaining an open circuit voltage in a present cycle according to an open circuit voltage of a previous cycle, a battery internal resistance of the previous cycle, and a battery capacitance of the previous cycle, where the battery internal resistance and the battery capacitance are updated according to the state of charge of the battery; and determining the state of charge of the battery according to the open circuit voltage in the present cycle.

Abstract: Disclosed is a method and a device for detecting states of a battery and a battery pack. The disclosure obtains a first state of charge and a second state of charge of the battery by use of a charge calculation method and a method based on battery model, respectively. The charge calculation method is more accurate when the charge-discharge current is large and the method based on battery model performs better in handling a small current, so that a chemistry state of charge obtained by performing a weighted calculation for the first state of charge and the second state of charge can represent the real state of charge of the battery more precisely. The disclosure settles the difficulty on parameter extraction of the conventional model method, eliminates the influence of the accumulated error of the charge calculation method, and combines the advantages of the method based on the battery model and the coulometer method.

Abstract: A method of driving an LED can include: (i) controlling a main power switch by a control circuit of an LED driver; (ii) turning on an auxiliary power switch when the main power switch is turned on such that a DC bus voltage is provided to the main power switch through the auxiliary power switch, and the main power switch outputs a driving current to a load; (iii) charging a capacitor by the DC bus voltage through the auxiliary power switch when the main power switch is turned off, where the capacitor is charged until a voltage across the capacitor reaches a predetermined stable voltage; (iv) clamping the voltage across the capacitor at the predetermined stable voltage; and (v) using the clamping voltage across the capacitor as a supply voltage for the control circuit.

Abstract: A method of driving an LED can include: (i) controlling a main power switch by a control circuit of an LED driver; (ii) turning on an auxiliary power switch when the main power switch is turned on such that a DC bus voltage is provided to the main power switch through the auxiliary power switch, and the main power switch outputs a driving current to a load; (iii) charging a capacitor by the DC bus voltage through the auxiliary power switch when the main power switch is turned off, where the capacitor is charged until a voltage across the capacitor reaches a predetermined stable voltage; (iv) clamping the voltage across the capacitor at the predetermined stable voltage; and (v) using the clamping voltage across the capacitor as a supply voltage for the control circuit.

Abstract: A driving circuit of a PMSM can include: a current sampling circuit that obtains a current sampling signal by sampling a rotor current of one phase of the PMSM; a sliding mode estimating circuit that receives the current sampling signal and a voltage sampling signal that represents a rotor voltage of the phase, estimates a back electromotive force information of the phase, and generates a first voltage signal that represents the back electromotive force information; a speed computing circuit that receives the first voltage signal, and generates an angular velocity signal that represents rotor cycle information; and a PWM control circuit that generates a PWM control signal according to the angular velocity signal, where the PWM control signal controls the turn on/off of switches in a three-phase inverter, to control an operating current of the PMSM to be a sine wave current.

Abstract: A driving circuit of a PMSM can include a current sampling circuit configured to generate a current sampling signal by sampling a stator current information of one phase of the permanent magnet synchronous motor; a BEMF circuit configured to receive the current sampling signal and a voltage sampling signal that represents a stator voltage of the phase, to estimate back electromotive force information of the phase, and to output a first voltage signal that represents the back electromotive force information; and a torque regulating circuit configured to generate an angle difference signal by calculating an angle difference between the first voltage signal and the current sampling signal, where the angle difference signal is configured to regulate an amplitude of a first U-shaped modulation wave such that a rotor current is in phase with the first U-shaped modulation wave for maximum torque per ampere.

Abstract: Disclosed herein are various battery power measurement devices, methods, and related apparatuses. In one embodiment, a method of measuring a battery power can include: (i) detecting a voltage and a temperature at an output terminal of a battery; (ii) obtaining a first correction coefficient based on a battery open-circuit voltage at a previous sample time; (iii) obtaining a second correction coefficient based on the battery temperature; (iv) calculating a real-time battery open-circuit voltage by using the voltage at the output terminal of the battery, the first and second correction coefficients, the battery open-circuit voltage at the previous sample time, and a time interval between the previous sample time and a present sample time; and (v) converting the real-time battery open-circuit voltage into a battery power measurement for display.

Abstract: A driving circuit of a PMSM can include a current sampling circuit configured to generate a current sampling signal by sampling a stator current information of one phase of the permanent magnet synchronous motor; a BEMF circuit configured to receive the current sampling signal and a voltage sampling signal that represents a stator voltage of the phase, to estimate back electromotive force information of the phase, and to output a first voltage signal that represents the back electromotive force information; and a torque regulating circuit configured to generate an angle difference signal by calculating an angle difference between the first voltage signal and the current sampling signal, where the angle difference signal is configured to regulate an amplitude of a first U-shaped modulation wave such that a rotor current is in phase with the first U-shaped modulation wave for maximum torque per ampere.

Abstract: A driving circuit of a PMSM can include: a current sampling circuit that obtains a current sampling signal by sampling a rotor current of one phase of the PMSM; a sliding mode estimating circuit that receives the current sampling signal and a voltage sampling signal that represents a rotor voltage of the phase, estimates a back electromotive force information of the phase, and generates a first voltage signal that represents the back electromotive force information; a speed computing circuit that receives the first voltage signal, and generates an angular velocity signal that represents rotor cycle information; and a PWM control circuit that generates a PWM control signal according to the angular velocity signal, where the PWM control signal controls the turn on/off of switches in a three-phase inverter, to control an operating current of the PMSM to be a sine wave current.

Abstract: The invention provides methods and compositions for recovering oil from stillage. The method comprises the addition of a surfactant and a microparticle comprising hydrophilic silica to a grain to ethanol stillage. The methods and compositions of the present invention release oil trapped in solid aggregates, increasing the total amount of oil extracted from the stillage.

Abstract: A structured porous metamaterial includes a three-dimensional matrix of at least one repeating base unit. The matrix is formed from an array of at least eight base units, each base unit including a platonic solid including at least one shaped void, wherein each base unit has void geometry tailored to provide a porosity of between 0.3 and 0.97, and to provide the metamaterial with a response that includes a Poisson's ratio of 0 to ?0.5 when under tension and compression, or negative linear compression (NLC), negative area compression (NAC), zero linear compression (ZLC), or zero area compression (ZAC) behaviour when under pressure.

Abstract: In one embodiment, harmonic control method for a flyback switching power supply, can include: (i) generating a sense voltage signal based on an output signal of the flyback switching power supply; (ii) generating a first compensation signal by determining and compensating an error between the sense voltage signal and a reference voltage; (iii) generating a second compensation signal by regulating the first compensation signal based on a duty cycle of a main power switch in the flyback switching power supply; and (iv) generating a control signal based on the second compensation signal and a triangular wave signal, to control the main power switch such that the output signal is substantially constant and an input current follows a waveform variation of an input voltage of the flyback switching power supply.

Abstract: A method of processing 2D graphics comprising generating a perspective projection of a 2D graphics by scaling the 2D graphics with a variable ratio, wherein scaling the 2D graphics with the variable ratio comprises interpolating the graphics with a filter, such that a point xp in the perspective projection is generated from a point x0 in the 2D graphics with a following equation x0=1/R(j)*xp+Ph(j), wherein j represents a line index of the point x0, 1/R(j) represents a scaling factor of a length in the 2D graphics versus a length in the perspective projection, and Ph(j) represents a phase shift.

Abstract: Disclosed is a computer implemented system that facilitates optimized panoramic stitching, comprising an interface that receives images corresponding to different camera locations. Each image comprises a first image depicting a portion of a scene from the point of view of a first camera location and a second image depicting a portion of a scene from the point of view of a second camera location.

Abstract: In one embodiment, a method of controlling an AC-DC power converter, can include: (i) receiving, by a filter capacitor, a first branch current from an input current of the AC-DC power converter; (ii) receiving, by a power converting circuit, a second branch current from the input current; (iii) receiving, by the power converting circuit, a feedback signal that represents an output signal of the power converting circuit, and a triangular wave signal that is determined by the first branch current; (iv) generating a first conduction time based on the feedback signal such that the power converting circuit produces a first converting current; and (v) generating a second conduction time based on the triangular wave signal such that the power converting circuit produces a second converting current having a same absolute value as the first branch current.