32results about How to "Reduce output ripple" patented technology

The present invention discloses a control circuit for reducing output ripple in a constant on-time switching regulator and a method thereof, for controlling a power stage. The control circuit determines whether a zero current period wherein an output current is zero is longer than a threshold period, and switches the on-time period to a shorter period if it is longer, whereby the power stage operates according to the shorter period while still in the discontinuous conduction mode (DCM).

The improved single stage power converter circuit topology substantially reduces EMI that is conducted to the AC line, reduces input AC current inrush, improves output ripples by the use of an auxiliary supply near zero crossings of the line AC voltage, provides Power Factors greater than 0.95, provides Total Harmonic Distortions less than 15%, and maintains constant power, including constant power in a non-linear output load. Further, this circuit topology provides output open and short circuit protections by reducing current stress in power components. This topology can also make the power source to appear as a fast-acting variable impedance source, an ideal source for powering an output load that has negative resistance characteristics such as gas discharge lamps.

The invention relates to a control circuit for a buck-boost power supply converter, which is used for providing a control signal to drive a buck-boost power level, so that input voltage is converted into output voltage, wherein the buck-boost power level comprises an inductor and at least two switches connected to the inductor. The control circuit is characterized by comprising a feedback circuit, an error amplifier, a dynamic work period generator and a driving circuit, wherein the feedback circuit detects the output voltage and generates a feedback signal; the error amplifier is connected with the feedback circuit and amplifies a difference value between the feedback signal and reference voltage to generate an error signal; the dynamic work period generator generates a first signal according to a detection signal after being started; and the driving circuit is connected with the error amplifier and the dynamic work period generator, and determines a control signal according to the error signal and the first signal. The control circuit and a control method for the buck-boost power supply converter have the advantages that: a switch witching order is optimized; the switching loss is reduced; the efficiency is improved; and output ripples are reduced.

Torque ripple of a motor due to a rotation detection device is reduced. A periodicity gain multiplier 51 multiplies the rotation angle θ of a detection target by a ripple periodic number m per rotation of the detection target. An adder 53 adds a phase adjusting value “ψ” from a phase adjustor 49 to the value “mθ”. The value “sin(mθ+ψ)”, which is calculated by a sine calculator 55, is multiplied by a predetermined gain G by an amplitude adjustor 57 and by the angular velocity ω of the detection target by a multiplier 59. A subtractor 61 subtracts the output of the multiplier 59 from the value “ω” and outputs “ω(1−Gsin(mθ+ψ))”. The output of the subtractor 61 and the output “mθ+ψ” of the adder 53 are input to the phase adjustor 49 and amplitude adjustor 57. The phase adjustor 49 calculates the phase adjusting value “ψ” based on the summation of the derivative values of the outputs from the subtractor 61sampled for each “π / 2” of the output from the adder 53. The amplitude adjustor 57 calculates the gain G based on the summation of the differences between averages of the sampled values at “0” and “π” of the output of the adder 53 and averages of the time integration value at the integral interval of “0” to “π”.

An ON-period setting circuit is provided in a fixed-ON-period switching power supply device that produces a desired output voltage from an input voltage by driving a coil by turning ON and OFF an output transistor and a synchronous rectification transistor. The ON-period setting circuit shortens the ON period the more the lighter the load is in a discontinuous-current mode. Or, the ON-period setting circuit transiently shortens the ON period on completion of a transition from a discontinuous-current mode to a continuous-current mode.

The multiple-cavity piezoelectric film driven pump is used in micro fluid conveyance and control. It consists of pump body with inlet and outlet passages, piezoelectric vibrator inside the pump cavity and inlet and outlet valves. It features at least two working cavities comprising piezoelectric vibrator and pump body connected serially or parallelly. Owing to that the pump has fluid outputting performance similar to that of several single-cavity piezoelectric pump connected serially or parallelly, the present invention has obviously raised output flow rate and pressure, and when in parallel connection, there is always output fluid in each work period and thus less output fluctuation.

A control circuit for a wireless power transmission device is provided. The wireless power transmission device includes a transmitter unit and a receiver unit. The control circuit includes a transmitter detecting unit, a first control unit and a driver unit. The transmitter detecting unit obtains an input power of the transmitter unit and generates an input power signal. The first control unit generates a control signal according to a result of comparing the input power signal with a reference input power signal. The driver unit drives switching devices of the transmitter unit according to the control signal. Consequently, the input power of the transmitter unit is adjusted, and an output ripple or a magnitude of the output of the receiver unit is adjusted.

The invention discloses a double-rotor motor with a permanent magnet-magnetic resistance axial magnetic flux composite structure. The double-rotor motor comprises stators (1), a first rotor (8) and a second rotor (6), wherein the stators (1) are arranged in an axial direction; the inner end surface of each stator (1) is a circular surface, grooves are distributed at the inner end surface of each stator in the radial direction, and three-phase distributed type armature windings (2) are arranged in the grooves; permanent magnets (3) are arranged at the end surface, facing the stators, of the first rotor (8), and are uniformly distributed at the circular surface; the end surface, facing the second rotor (6), of the first rotor (8) is provided with convex poles (4) which are distributed along the circumference; grooves are distributed at the inner end surface of the second rotor (6) in the radial direction, and three-phase centralized type windings (5) are arranged in the grooves. The double-rotor motor has the beneficial effects that the toothed groove torque of the system is weakened, and the vibration and electromagnetic noise are decreased; the power density and power factor of the system are improved, and the transfer efficiency is improved; the electromagnetic torque of the system is improved, and the driving force of a hybrid automobile is improved.

Disclosed is a control circuit for a buck-boost power converter. The control circuit is used for providing a control signal to drive a buck-boost power level so as to convert an input voltage into an output voltage. The buck-boost power level comprises an inductor and at least two switches connected with the inductor. The control circuit is characterized by comprising a feedback circuit, an error amplifier, a dynamic working period generator and a driving circuit, wherein the feedback circuit detects the output voltage to generate a feedback signal, the error amplifier is connected with the feedback circuit and amplifies a difference value between the feedback signal and a reference voltage to generate an error signal, the dynamic working period generator generates a first signal according to a detection signal after being started, and the driving circuit is connected with the error amplifier and the dynamic working period generator and determines the control signal according to the error signal and the first signal. The control circuit and method for the buck-boost power converter have the advantages that the on-off switching sequence is optimized, switching losses are reduced, efficiency is improved, and output ripples are reduced.

Provided is a switching controller for a flyback type power converter, comprising a switching circuit, a sampling maintaining circuit, a voltage detecting circuit, an oscillator, and a comparator. When the input voltage of the flyback type power converter is lower than the low threshold, the voltage detecting circuit generates maintaining signals. The maintaining signals are generated based on the output voltage of the flyback type power converter. An oscillating circuit limits the maximum frequency of the switching signals. The maximum frequency is increased with the decrease of the adjusting signals. When the level of the input voltage is lower than the minimum threshold, the adjusting signals associated with the level of the input voltage are used for generating control signals. The control signals are used for making the flyback type power converter operate under the operation of the continuous current mode. Therefore, the usage of an input capacitor can be avoided and the making cost is cut down.

The invention provides a control circuit for a buck-boost power converter. The control circuit is used for providing a control signal so as to drive the buck-boost power level and convert an input voltage into an output voltage. The buck-boost power level includes an inductor and at least two switches connected with the inductor. The control circuit is characterized by comprising a feedback circuit, an error amplifier, a dynamic work cycle generator and a driving circuit, the feedback circuit detects a feedback signal generated by the output voltage, the error amplifier is connected with the feedback circuit and used for amplifying the difference between the feedback circuit and a reference voltage and generating an error signal, the dynamic work cycle generator generates a first signal according to a detection signal after being started, and the driving circuit connects the error amplifier with the dynamic work cycle generator and determines the control signal according to the error signal and the first signal. The control circuit and method for the buck-boost power converter have the advantages that the switching sequence of the switches is optimized, switching loss is reduced, efficacy is improved, and output ripples are reduced.

The invention discloses a novel isolation actively-clamped interleaved parallel Boost soft switching converter and a working method thereof. A first inductor, a second inductor and a third inductor constitute one set of coupled inductors. A fourth inductor, a fifth inductor and a sixth inductor constitute the other set of coupled inductors. The number of turns of the second inductor, the third inductor, the fifth inductor and the sixth inductor is n2. The number of turns of the first inductor and the fourth inductor is n1. A seventh inductor and an eighth inductor are excitation inductors of coupled inductors. A ninth inductor and a tenth inductor are equivalent inductors of coupled inductors. A first MOS tube and a second MOS tube are main switching tubes. A first diode and a second diode are output diodes. A first capacitor and a second capacitor are parallel capacitors on the first MOS tube and the second MOS tube. A third capacitor is a clamped capacitor. The turns ratio N of coupled inductors is defined as n2:n1.

The invention provides a bionic type piezoelectric pump. The bionic type piezoelectric pump comprises an upper sealing piece, a lower sealing piece, a cavity, a water inlet hose, a water outlet hose, a flexible piezoelectric driving piece B and a flexible piezoelectric driving piece A. A counter bore A, a water inlet and a water outlet are formed in the upper sealing piece. The water inlet is provided with a valvula valve A, and the water outlet is provided with a valvula valve C. The cavity is provided with a pump cavity, a water inlet connecting pipe, a water outlet connecting pipe, a water inlet water-collection hole and a water outlet water-collection hole. A one-way flowing valvula valve B is arranged in the pump cavity. The counter bore A corresponds to the pump cavity in position and is used for storing the flexible piezoelectric driving piece A. The lower sealing piece is provided with a counter bore B. The counter bore B is used for mounting and bonding the flexible piezoelectric driving piece B therein. According to the bionic type piezoelectric pump, a double-cavity double-vibrator structure is adopted; the pump cavity, the inlet and the outlet are provided with the valvula valves; the heart of a human body is simulated; and the bionic type piezoelectric pump is provided with the multiple pump cavities and the multiple valvula valves, and the capacity and pressure of the pump can be effectively increased. New reference is provided for research of an artificial heart.

The rotary detector according to this invention comprises a rotary detector unit C1, C1' which detects rotary motion of a rotor; and a rotary calculator unit C2, C2' , C2" comprising a rotation angle detector, which detects the rotation angle of the rotor, and an angle speed detector 47 which detects the angle speed of the rotor, based on the output of the rotary detector unit. The rotary calculator unit comprises a trigonometrical calculator C3, C3', C3" which calculates a sine value or a cosine value of the rotation angle detected by the rotary detector; a gain adjuster 57, 57', 57" which multiplies the sine value or the cosine value, calculated by the trigonometrical calculator, by a predetermined gain; a multiplier 59, 59' which multiplies the output of the gain adjuster by the output of the angle speed detector; and a subtracter 61, 61' which subtracts the output of the multiplier from the output of the angle speed detector.

The invention relates to a novel interleaving BUCK converter and a ripple elimination method thereof. The converter comprises (2n + 2) IGBTs, (n + 1) inductors and two capacitors, wherein n is a natural number; the two IGBTs and the inductor form a phase bridge arm, and the converter is provided with (n + 1) phase bridge arms, wherein the second-phase bridge arm to the (n + 1)-th-phase bridge arm are connected in parallel, the parallel-connected bridge arms are directly connected with the capacitor CP in parallel, and the capacitor CS is connected between the inductor LS of the first-phase bridge arm and the capacitor CP in series; the first-phase bridge arm serves as an output ripple compensation bridge arm, and the second-phase bridge arm to the (n + 1)-th-phase bridge arm serve as power bridge arms and are used for power transmission. According to the invention, the switching loss, the cost and the volume of the interleaved BUCK converter can be reduced.

The invention belongs to the technical field of water pumps, and discloses a water pump. The water pump comprises a pump body, an eccentric shaft, a driving wheel, plungers and pistons. A water inlet,a water outlet, an opening P and an opening T are formed in the pump body, a plurality of piston cavities are formed in the pump body, the pistons are located in the piston cavities and can slide back and forth, the interiors of the piston cavities are divided into oil cavities and water cavities; the oil cavities alternately communicates with the opening P and the opening T, the water cavities alternately communicates with the water inlet and the water outlet, the outer surface of the driving wheel is a regular polygon, the driving wheel sleeves the eccentric section of the eccentric shaft and can perform relative sliding in the circumferential direction, one ends of the plungers are connected with the pistons, the other ends of the plungers are in sliding contact with the outer surfaceof the driving wheel, during the rotation of the eccentric shaft, and the communication relationship between the opening P and the opening T and different oil cavities and the communication relationship between the water inlet and the water outlet and the different water cavities are switched. The water pump can perform continuous compression acting of water mediums under hydraulic pressure, is simple in structure and low in cost, the use of a motor and an impeller is saved, the working temperature is reduced, and long-term continuous work is achieved.

The present invention proposes a switching controller of a flyback power converter. The switching controller includes a switching circuit, a sample-and-hold circuit, a voltage detection circuit, an oscillation circuit, and a comparator. The voltage detection circuit generates a holding signal when a level of an input voltage of the flyback power converter is lower than a low-threshold. The oscillation circuit limits the maximum frequency of switching signal. The maximum frequency is increased in response to a decrement of a modulation signal. The modulation signal correlated with a level of the input voltage is used to generate a control signal when the level of the input voltage is lower than an ultra-low-threshold. The control signal is enabled to operate the flyback power converter in continuous current mode operation. Therefore, an input capacitor can be eliminated and manufacturing cost is saved.

The invention provides a control method and a control system of a chopper converter, the chopper converter comprises a Buck converter and a Boost converter which are connected in series, the adopted control method comprises the following steps: sampling an output voltage value and an output current value of the Buck converter, carrying out closed-loop regulation based on the collected output voltage value and the output current value, and controlling the output voltage value and the output current value of the Buck converter according to the closed-loop regulation. The control duty ratio of the Buck converter is output, and the control duty ratio of the Boost converter is calculated based on the control duty ratio of the Buck converter so as to control the output of the chopper converter; the beneficial effects of the invention are that a traditional four-order control system is changed into a two-order control system, the difficulty of parameter adjustment control is reduced, the calculation and configuration of the control margin are controlled, the response speed of the system is improved, the front-stage BOOST converter and the rear-stage BUCK converter are subjected to synchronous closed-loop control, and the output ripple and EMI influence are effectively reduced.

The invention provides a bionic type piezoelectric pump. The bionic type piezoelectric pump comprises an upper sealing piece, a lower sealing piece, a cavity, a water inlet hose, a water outlet hose, a flexible piezoelectric driving piece B and a flexible piezoelectric driving piece A. A counter bore A, a water inlet and a water outlet are formed in the upper sealing piece. The water inlet is provided with a valvula valve A, and the water outlet is provided with a valvula valve C. The cavity is provided with a pump cavity, a water inlet connecting pipe, a water outlet connecting pipe, a water inlet water-collection hole and a water outlet water-collection hole. A one-way flowing valvula valve B is arranged in the pump cavity. The counter bore A corresponds to the pump cavity in position and is used for storing the flexible piezoelectric driving piece A. The lower sealing piece is provided with a counter bore B. The counter bore B is used for mounting and bonding the flexible piezoelectric driving piece B therein. According to the bionic type piezoelectric pump, a double-cavity double-vibrator structure is adopted; the pump cavity, the inlet and the outlet are provided with the valvula valves; the heart of a human body is simulated; and the bionic type piezoelectric pump is provided with the multiple pump cavities and the multiple valvula valves, and the capacity and pressure of the pump can be effectively increased. New reference is provided for research of an artificial heart.

The invention discloses a transfer pump of a high viscosity fluid. The transfer pump which comprises an end cover (1), an internal gear (2), a fixed shaft (4), a pump body (5), an external gear (7), a right end cover (8), a support (12), and a transmission shaft (15) is characterized in that: an inner geared gear pair which is composed of the internal gear (2) and the external gear (7) is arranged in the pump body (5); the external gear (7) is a driving gear, the internal gear (2) is a driven gear; tooth profile curves of the gears are arc in shape, and the centers of the internal arc and the external arc of a crescent shaped plate are respectively coincident with centers of the internal gear (2) and the external gear (7). The transfer pump of the present invention has the advantages of strong self-priming capability, realization of high viscosity fluid transfer, stable transfer, long life, low cost and the like.

Disclosed is a control circuit for a buck-boost power converter. The control circuit is used for providing a control signal to drive a buck-boost power level so as to convert an input voltage into an output voltage. The buck-boost power level comprises an inductor and at least two switches connected with the inductor. The control circuit is characterized by comprising a feedback circuit, an error amplifier, a dynamic working period generator and a driving circuit, wherein the feedback circuit detects the output voltage to generate a feedback signal, the error amplifier is connected with the feedback circuit and amplifies a difference value between the feedback signal and a reference voltage to generate an error signal, the dynamic working period generator generates a first signal according to a detection signal after being started, and the driving circuit is connected with the error amplifier and the dynamic working period generator and determines the control signal according to the error signal and the first signal. The control circuit and method for the buck-boost power converter have the advantages that the on-off switching sequence is optimized, switching losses are reduced, efficiency is improved, and output ripples are reduced.

The present invention relates to micro mechanical reciprocating membrane pump, and is one kind of micro mechanical reciprocating membrane pump for biochemical microanalysis. The micro mechanical reciprocating membrane pump has piezoelectric driving device as driving source, which makes the membrane vibrate to force the pump cavity to suck in and pump out fluid reciprocally; inertial fairing flow channel as no-motion valve to make the flow damp in some direction greater than that in the other direction; inertial ring cavity to further increase the damp difference between two directions. The present invention has simple structure, can drive fluid containing relatively large grain, has no damage to cell or macro molecule in fluid, no dead volume and constant flow rate and other advantages, and is suitable for driving micro volume fluid in micro flow channel of cross section size in decades and hundreds microns.

The invention relates to a control circuit for a buck-boost power supply converter, which is used for providing a control signal to drive a buck-boost power level, so that input voltage is converted into output voltage, wherein the buck-boost power level comprises an inductor and at least two switches connected to the inductor. The control circuit is characterized by comprising a feedback circuit, an error amplifier, a dynamic work period generator and a driving circuit, wherein the feedback circuit detects the output voltage and generates a feedback signal; the error amplifier is connected with the feedback circuit and amplifies a difference value between the feedback signal and reference voltage to generate an error signal; the dynamic work period generator generates a first signal according to a detection signal after being started; and the driving circuit is connected with the error amplifier and the dynamic work period generator, and determines a control signal according to the error signal and the first signal. The control circuit and a control method for the buck-boost power supply converter have the advantages that: a switch witching order is optimized; the switching loss is reduced; the efficiency is improved; and output ripples are reduced.

The invention relates to a buck-boost DC converter which can achieve a characteristic of zero-ripple voltage, wherein the zero-ripple voltage represents extremely low ripple voltage close to zero in engineering. The buck-boost DC converter comprises a ripple elimination inductor, an electric energy isolation and conversion unit, a power switch, a first inductor, a first capacitor, a second capacitor and a rectifying element, wherein the electric energy isolation and conversion unit is electrically connected to the ripple elimination inductor and comprises a plurality of coils, and the coils divide the buck-boost DC converter into an input stage and an output stage; the power switch, the first inductor and the first capacitor are located at the input stage and electrically connected to the electric energy isolation and conversion unit and the second capacitor and the rectifying element are located at the output stage and electrically connected to the electric energy isolation and conversion unit.

The invention relates to a buck-boost DC converter which can achieve a characteristic of zero-ripple voltage, wherein the zero-ripple voltage represents extremely low ripple voltage close to zero in engineering. The buck-boost DC converter comprises a ripple elimination inductor, an electric energy isolation and conversion unit, a power switch, a first inductor, a first capacitor, a second capacitor and a rectifying element, wherein the electric energy isolation and conversion unit is electrically connected to the ripple elimination inductor and comprises a plurality of coils, and the coils divide the buck-boost DC converter into an input stage and an output stage; the power switch, the first inductor and the first capacitor are located at the input stage and electrically connected to the electric energy isolation and conversion unit and the second capacitor and the rectifying element are located at the output stage and electrically connected to the electric energy isolation and conversion unit.

Disclosed is a control circuit for a buck-boost power converter. The control circuit is used for providing a control signal to drive a buck-boost power level so as to convert an input voltage into an output voltage. The buck-boost power level comprises an inductor and at least two switches connected with the inductor. The control circuit is characterized by comprising a feedback circuit, an error amplifier, a dynamic working period generator and a driving circuit, wherein the feedback circuit detects the output voltage to generate a feedback signal, the error amplifier is connected with the feedback circuit and amplifies a difference value between the feedback signal and a reference voltage to generate an error signal, the dynamic working period generator generates a first signal according to a detection signal after being started, and the driving circuit is connected with the error amplifier and the dynamic working period generator and determines the control signal according to the error signal and the first signal. The control circuit and method for the buck-boost power converter have the advantages that the on-off switching sequence is optimized, switching losses are reduced, efficiency is improved, and output ripples are reduced.

The invention provides a double-path rectification power supply module and belongs to the technical field of power electronics. The double-path AC-DC (Alternating Current to Direct Current) integratedpower supply module comprises an AC-DC circuit and a DC-DC circuit; an externally input AC is converted into a DC stably output after sequentially passing through the AC-DC circuit and the DC-DC circuit; the AC-DC circuit comprises a first filtering circuit, an uncontrolled rectification circuit and a second filtering circuit; and the DC-DC circuit comprises a power conversion circuit, a third filtering circuit, a main control circuit and a feedback circuit. According to the invention, by arranging the filtering circuits, the feedback circuit and the main control circuit, circuit output can be effectively stabilized; and particularly output common mode inductor and resistor newly added at the DC-DC circuit part can obviously reduce output ripples and noise of the power supply module and promote performance of the power supply module.