71results about How to "Small output voltage ripple" patented technology

A switching power supply circuit includes a transformer having a primary winding, a secondary winding, and a feedback winding, a switching element connected in series to a first of the primary winding, a control circuit disposed between a control terminal of the switching element and the feedback winding, a starting circuit connected between a second end of the primary winding and the control terminal of the switching element, and a rectifying / smoothing circuit connected to the secondary winding. The control circuit includes a first delay circuit for determining the time that elapses before the switching element is turned on by a voltage generated at the feedback winding, a control element driven to prevent the switching element from turning on or forcibly turn off the switching element, and a second delay circuit for changing a delay time such that, under rated load or under heavy load, the switching element is turned off by driving the control element after the switching element is turned on by the voltage generated at the feedback winding, and, under light load, the turn-on of the switching element is blocked by driving the control element before the switching element is turned on by the voltage generated at the feedback winding.

The invention discloses a pulse hopping mode PSM control method suitable for a primary side feed-back fly-back converter. The method comprises the following steps: indirectly sampling output voltage through an auxiliary winding; outputting the value of the output voltage through a comparison module; selecting a proper duration hopping mode from a duration hopping control module by adding the judgment of a peak current module and a duration hopping calculation module; finally, outputting a proper duty cycle through a DPWM module to drive a switch MOS transistor and control the voltage-stabilized output of digital power. Through the adoption of the method, on one hand, the light load efficiency can be high by switching off a part of circuit modules of a system in a part of switch duration; on the other hand, compared with the conventional PFM control method, the pulse hopping mode PSM control method has the advantages that PSM control is simpler, filtering can be easier due to a controllable frequency range, and the EMI can be reduced effectively.

The invention provides a full-bridge LLC resonant conversion circuit. The full-bridge LLC resonant conversion circuit comprises a conversion circuit and a rectification circuit, wherein the conversioncircuit comprises four switch tubes Q1, Q2, Q3 and Q4, the conversion circuit is partially provided with a resonant capacitor Cr and a resonant inductor Lr which are connected in series, one end of the resonant inductor Cr is connected with a bridge arm, the resonant inductor Lr is connected with the other one bridge arm. The invention provides a wide-range output control method of the full-bridge LLC resonant conversion circuit. According to the wide-range output control method, the full-bridge LLC resonant conversion circuit works in a full-bridge working mode when an output voltage U0 is larger than (U<0max>+U<0min>) / 2; and the switching between the full-bridge working mode and a half-bridge working mode is performed when the full-bridge LLC resonant conversion circuit works in the half-bridge working mode and the output voltage is equal to (U<0max>+U<0min>) / 2. By the full-bridge LLC resonant conversion circuit, a wider output voltage range can be provided, and a better output characteristic index such as higher efficiency and smaller output voltage ripple can be obtained.

The invention discloses a constant voltage output charge pump circuit. The circuit comprises a pump circuit, a clock generating circuit, a first feedback loop circuit and a second feedback loop circuit. The pump circuit comprises a switching device for switching clock signals when the pump circuit is switched to work between the first stage and the second stage and an adjusting device for adjusting the magnitude of the output voltage of the pump circuit of the second stage. The clock generating circuit is used for generating clock signals enabling the switching device to work. The first feedback loop circuit monitors the output voltage of the pump circuit to generate a corrected voltage to the adjusting device of the pump voltage so as to control the output voltage of the pump circuit. The second feedback loop circuit monitors the output voltage of the pump circuit to generate an enabling signal to the clock generating circuit so as to determine whether the pump circuit works and control the output voltage of the pump circuit. Therefore, the charge pump circuit can keep constant output voltage under the condition of variable input voltage or load so as to prevent the output voltage from changing together with the change of the input voltage or the load.

A PWM controller and control method for a DC-DC voltage converter filter the high-frequency component of the voltage at the phase node between high-side and low-side elements of the voltage converter to generate a signal synchronous and in phase or out-of-phase with the inductor current of the voltage converter, to achieve a low-ripple output voltage and stable loop control.

The invention relates to the field of wireless communication, in particular to an acquisition and processing system of embedded global system for mobile communications for railway (GSM-R) network interference signals based on multiprocessors. The system comprises a processor, a power module, an analog to digital (AD) data acquisition module, a data and program storage module, a remote data transmission module and a data backup module, the AD data acquisition module coverts collected intermediate frequency analog signals of uplink frequency ranges and downlink frequency ranges of a GSM-R into digital signals to be sent to a digital signal processor (DSP) core in the processor, the DSP core operates and processes to store the digital signals in double data rate 2 (DDR2) chip in the data and program storage module, simultaneously the serial advanced technology attachment (SATA) connector stores the digital signals in a high-capacity rigid disk, the AD data acquisition module starts the intermediate frequency analog signals in an abnormal signal-collected frequency range when data acquisition is abnormal, and the AD data acquisition module is communicated with an upper computer through an Ethernet transceiver.

The invention discloses a wide range output control method for an LLC resonant transformation circuit. The LLC resonant transformation circuit works under different working modes depending on correlation between the output voltage and the load size. The trend is that the LLC resonant transformation circuit works under a variable frequency working mode when the LLC resonant transformation circuit is in a high output voltage or heavy load state; when the LLC resonant transformation circuit is in a low output voltage or light load state, the LLC resonant transformer works under a working mode with a fixed frequency variable effective duty ratio or under an intermittent working mode with a fixed frequency fixed effective duty ratio. According to the method provided by the invention, the wide range output voltage requirement of the LLC resonant transformation circuit can be effectively met.

The invention discloses a method and a device for controlling a digital high-frequency and high-voltage power supply of an electron beam welding machine, wherein three-phase commercial power is used for power supply, and an AC (alternating current) to DC (direct current) to DC to AC to DC current change way is adopted, intermediate DC to DC is of a high-frequency chopping direct-current voltage regulation link, and DC to AC is of a high-frequency inversion link; a high-frequency and high-voltage transformer is used for realizing energy transfer, voltage boosting and high-voltage insulation; a negative feedback control way is adopted by the high-voltage power supply, a digital proportional-integral (PI) regulator mechanism is adopted, regulation is completed in a digital controller, and a PWM (pulse width modulation) pulse signal of pulse width change is generated to control the high-frequency chopping voltage regulation unit so as to complete closed-loop control of the high-voltage power supply and realize automatic stable regulation of output high voltage. The method and the device disclosed by the invention have the characteristics of small harmonic interference on a power grid, output high voltage ripple, high precision, high efficiency and all-digital property.

A car permanent magnet generator is mainly composed of a rear cover, a three-phase bridge type controlled rectifier, an electronic voltage regulating controller, a rear end cover, a stator, a permanent magnet rotor, a bearing, a front end cover, a belt wheel, wherein the belt wheel drives the permanent magnet rotor to rotate, to cause the stator winding to induce out the three-phase alternating current, then is set as the DC output through the three-phase bridge type controlled rectifier. The electronic voltage regulating controller controls the angle of current flow of the thyristor, to cause the generator to output the stable DC voltage, characterized in that, the stator is arranged with two sets of three-phase windings, one is in the 'Y'-connection, and the other is in the 'triangle'-connection, which constitute two three-phase controlled bridge type rectifying circuits with the three-phase bridge type controlled rectifier, wherein the two rectifying circuits are in the parallel output. Due to the voltage phase difference 30 of the two windings, the output voltage pulses every 30 degrees, so the more the pulse times of the rectifying output voltage in a period is, the smaller the ripple of the output voltage of the car permanent magnet generator is.

The invention provides a drive control method and drive control circuit with the object of reducing the loss of asymmetrical half-bridge fly-back converters in outputting light load or no load wherein the drive control circuit comprises a drive control module used to realize drive control over a transistor. The transistor consists mainly of a main switch tube and a clamp switch tube as well as a light load detection control circuit. The light load detection control circuit comprises a feedback signal control module and a frequency control module wherein the feedback signal control module detects the output load of a switch converter, compares the output load signal of the switch converter to see if it is lower than a set load point or not and outputs the comparison result of the detection value to the frequency control module. The frequency control module, based on the comparison result, maintains or raises the working frequency of the drive control module. That means if it is not light load, the working frequency of the drive control module stays unchanged. And if it is light load, the working frequency of the drive control module is raised.

The invention discloses a control device used for improving the PF value of a DCM Buck PFC converter. The control device comprises a main power circuit and a control circuit. The main power circuit comprises an input voltage source vin, an EMI filter, a diode rectifier circuit RB, a Buck inductor Lb, a switch tube Qb, a diode Db, an output capacitor Co and a load RLd. The control circuit comprises an output voltage feedback control circuit, an input voltage feedforward circuit, a second multiplier and a sawtooth wave comparing and switch tube drive circuit. Input voltage feedforward and output voltage feedback are introduced, so that the duty cycle of the converter changes according to a certain rule in a power frequency cycle, and the PF value is improved to close to 1 in the AC input voltage range between 90V and 264V. The control device provided by the invention has the advantages of small output voltage ripple, small switch tube conduction loss, reduced required diode stress and the like.

The invention provides a boost-buck switch circuit. According to the boost-buck switch circuit, under a buck mode, a fixed duration conduction circuit or a fixed duration off circuit is employed to control a buck switch pair; under a boost mode, the fixed duration conduction circuit or the fixed duration off circuit is employed to control a boost switch pair; under a boost-buck mode, the fixed duration conduction circuit or the fixed duration off circuit is employed to simultaneously control the buck switch pair and the boost switch pair. The boost-buck switch circuit employs a combined mode of voltage feedback and current feedback to realize constant voltage output and constant current output of a system and can be applied to a cell control system. The boost-buck switch circuit needs no loop compensation circuit, the circuit structure is simple, moreover, each work mode can be conveniently switched, seamless joint of each work mode can be realized, and relatively good transient characteristics are realized.

The invention discloses a charge pump and a working method thereof. The charge pump comprises a reference voltage generation circuit, a voltage comparator, a clock generator, a charge transferring capacitor, a voltage-stabilizing capacitor, a first switch, a second switch, a third switch and a fourth switch; through charging the charge transferring capacitor and transferring charges on the charged charge transferring capacitor to the output end of the charge pump, an electrical level higher than an input voltage is output, and when the charge transferring capacitor is charged every time, the charge transferring capacitor is not charged fully, but is only charged to a set voltage, and then the charging is stopped. According to the invention, the conversion rate of the charge pump can be increased, and the voltage ripples output by a circuit of the charge pump are reduced.

The invention provides a driving control system of an electric vehicle. The driving control system comprises a heating circuit (11) and a load capacitor C12, wherein the heating circuit (11) is used for being connected with a vehicle-mounted battery (5) to form a heating loop; and the driving control system further comprises a current storage element L11, wherein the current storage element L11 and the load capacitor C12 are connected in series and are then connected with the heating circuit (11) in parallel. According to the driving control system of the electric vehicle provided by the invention, the heating circuit (11) and the load capacitor C12 can work simultaneously without affecting each other.

A PWM controller and control method for a DC-DC voltage converter filter the high-frequency component of the voltage at the phase node between high-side and low-side elements of the voltage converter to generate a signal synchronous and in phase or out-of-phase with the inductor current of the voltage converter, to achieve a low-ripple output voltage and stable loop control.

The invention discloses a novel axial magnetic flux double-salient permanent magnet generator. The technical problem that an existing generator is excessively complex in structure, large in self energy consumption and the like is solved. According to the technical scheme, the novel axial magnetic flux double-salient permanent magnet generator comprises a rotor, a generator outer stator, a generator inner stator, a permanent magnet ring and a rotor shaft. The generator inner stator is embedded in the generator outer stator, and a gap is reserved between the generator inner stator and the generator outer stator, the permanent magnet ring is installed in the gap, the rotor shaft is arranged in the center of the rotor, and the rotor shaft and the rotor are fixed into a whole; the rotor shaft penetrates through the center of the generator inner stator and is not in contact with the generator inner stator; the rotor is located above the generator outer stator and the generator inner stator. By means of the novel axial magnetic flux double-salient permanent magnet generator, a double-salient permanent magnet motor and an axial magnetic flux motor are organically combined; the novel axial magnetic flux double-salient permanent magnet generator has the advantages of being high in efficiency, high in power density, compact in structure, low in noise and low in starting air speed.

The invention relates to a magnetic suspension bearing disc hybrid excitation doubly salient wind generator, and aims to solve the technical problem that an existing magnetic suspension wind generator system is too complicated in structure, high in energy consumption, inapplicable to small and medium fans and the like. The technical scheme includes that the magnetic suspension bearing disc hybrid excitation doubly salient wind generator comprises a rotor, two generator stators, two permanent magnet rings, three magnetic suspension bearing stators, fan blades and a rotor shaft, magnetic suspension bearing control windings are wound on the magnetic suspension bearing stators, the fan blades are mounted at one end of the rotor shaft, the rotor is mounted at the other end of the rotor shaft, the fan blades, the rotor and the rotor shaft synchronously rotate, the two permanent magnet rings are connected with the two generator stators respectively and further connected with the magnetic suspension bearing stators, the permanent magnet rings are embedded among the magnetic suspension bearing stators and the generator stators, the magnetic suspension bearing stators are uniformly distributed on the periphery of the rotor, the periphery of the rotor extends into the magnetic suspension bearing stators, and air gaps are reserved among the magnetic suspension bearing stators and two planes of the rotor.

The invention discloses a discrete expansion phase shift control method and device for a dual-active-bridge DC-DC converter. The method comprises the steps of: sampling an output voltage value Uo of the dual-active-bridge DC-DC converter at the starting moment of each switching period, judging which stage of m-stage output voltage the Uo belongs to, and enabling the boundary of each stage of output voltage to be Uref+ / -jeref, setting a primary side inward phase shift ratio and an outward phase shift ratio between primary side secondary sides of the dual-active-bridge DC-DC converter corresponding to m levels of output voltages respectively, and performing phase shift respectively to obtain m groups of discrete phase shift control pulse groups, according to the judgment result of the Uo, selecting a corresponding group from the m discrete phase shift control pulse groups to control a switching tube of the dual-active-bridge DC-DC converter, thus rapidly stabilizing the Uo at Uref, and increasing the transient response speed of the system; in addition, optimization of the backflow power is further provided, the phase shift ratio corresponding to the control pulse group is set according to the expected output power and the voltage conversion ratio, the backflow power can be reduced, the control loop is simple and reliable, and a compensation network and a load current loop are notneeded.

The invention provides a control circuit used for controlling a single-induction and multi-output system. The control circuit adopts a first control loop to realize control on a current peak mode of the system, and adopts an algebraic relation of various outputs of the system for a second control loop to control the duty ratio of each switching device of a main circuit of the system so as to realize the control on each output voltage of the system, reduce the ripple wave of each output voltage and optimize the performance of the system.

The invention provides a method for reducing output voltage ripples of a Boost power electronics inverter. The method comprises the following steps of: firstly calculating a current reference value Iref and then calculating a voltage reference value Vref; then calculating a minimal load resistance value Rmin and determining a ripple voltage Vripple; and finally on the premise that the load resistance of the convertor is greater than the Rmin, controlling a switch of the convertor as follows: measuring an output voltage vC, measuring an inductive current iL, and when the vC is less than the reference voltage Vref and the iL is less than or equal to zero, controlling the switch to be switched on; and measuring the inductive current iL, and when the iL is greater than the reference current Iref, controlling the switch to be switched off. The method provided by the invention has the beneficial effects of quickening the output voltage response speed of the convertor and reducing the output voltage ripples of the convertor.

A constant-voltage circuit includes a switching regulator and a series regulator each configured to start operating according to a selection signal input from outside the integrated circuit for exclusively causing one of the switching or the series regulators to operate, convert an input voltage to a rated voltage and to output the voltage to an output terminal. The switching regulator performs a soft-start operation for raising an output voltage to the rated voltage at a constant speed when starting operation. The series regulator regulates a current so that an output current does not exceed a predetermined value, simultaneously starts operating when the switching regulator starts operating, and automatically stops outputting a current to the output terminal when the soft-start operation is completed. A semiconductor apparatus provided with a predetermined function includes the constant-voltage circuit. A control method controls the constant-voltage circuit.

A constant-voltage circuit includes a switching regulator and a series regulator each configured to start operating according to a selection signal input from outside the integrated circuit for exclusively causing one of the switching or the series regulators to operate, convert an input voltage to a rated voltage and to output the voltage to an output terminal. The switching regulator performs a soft-start operation for raising an output voltage to the rated voltage at a constant speed when starting operation. The series regulator regulates a current so that an output current does not exceed a predetermined value, simultaneously starts operating when the switching regulator starts operating, and automatically stops outputting a current to the output terminal when the soft-start operation is completed. A semiconductor apparatus provided with a predetermined function includes the constant-voltage circuit. A control method controls the constant-voltage circuit.

Embodiments of the invention provide a charge pump circuit and a memory. The charge pump circuit comprises a charge pump and a comparator, and the charge pump circuit further comprises a ripple suppression circuit, wherein the ripple suppression circuit comprises an operational amplifier and a discharge module, a non-inverting input end of the operational amplifier is connected with a non-inverting input end of the comparator, an inverting input end of the operational amplifier is connected with a reference input voltage providing end of the comparator, a gain of the operational amplifier is greater than a gain of the comparator, the discharge module is connected with an output end of the operational amplifier and an output end of a charge pump, and when a voltage difference between a voltage of the non-inverting input end of the comparator and a reference input voltage is greater than or equal to voltage accuracy of the operational amplifier, the discharge module discharges the chargepump according to an output voltage of the operational amplifier. Through adoption of the charge pump circuit, output ripples of the charge pump circuit are reduced effectively, filter capacitance isreduced, and correspondingly, the area of the memory is reduced.

The invention relates to a single-stage AC-DC multi-output electrolytic-capacitor-free high-power LED driving power source and a control method. The LED driving power source comprises an input filtercircuit, a bridgeless Boost PFC circuit, a half-bridge LLC resonant circuit and an LED load. The bridgeless Boost PFC circuit and the half-bridge LLC resonant circuit are integrated into a single-stage structure by sharing two switching tubes. A multi-series isolation transformer LLC converter drives the LED load. An LED driving circuit uses a common control strategy with a PFM and PWM variable duty cycle technology. In this control strategy, a power factor is increased, a DC bus voltage is lowered, output voltage ripple is reduced, and the required capacitance of the circuit is e reduced so that a ceramic capacitor with a long service life replaces an electrolytic capacitor to extend the service life of the driving power source. The circuit and the control strategy of the present invention have high efficiency, a high power factor, less components, low cost, low DC bus voltage, and no electrolytic capacitor.

The invention discloses a pseudo continuous conduction mode switch converter set follow current duty ratio control method and an apparatus. Through comparing a ripple voltage signal on an output capacitance equivalent series resistor to an error signal generated by an output voltage and a reference voltage which pass through an error amplifier, control to a main switch tube of a pseudo continuous conduction mode switch converter is completed and voltage stabilization of the output voltage is realized. Through carrying out set follow current duty ratio control on a follow current switch tube, dynamic follow current of an inductive current is realized. By using the method and the apparatus of the invention, the pseudo continuous conduction mode switch converter possesses the advantages that control is simple; stability is good; a load scope is wide; a light load output voltage ripple is small; input and a load transient response speed are fast; and full-load efficiency is high and so on.

The invention relates to a multi-winding, divided power supply voltage-type monopole multi-input low-frequency link inverter. The circuit structure is formed by connecting a plurality of high-frequency inverters which are isolated to another other and are provided with input filters and a shared output filtering circuit through a multi-input and single-output low-frequency transformer, each inputend of the low-frequency transformer is connected with an output end of each high-frequency inversion circuit in one-to-one correspondence, and an output end of the low-frequency transformer is connected with an input end of the output filtering circuit. The inverter has the characteristics of divided power supply of various input sources, isolation among the high-frequency inversion circuits, simple circuit topology, monopole power conversion, high voltage matching capability, high conversion efficiency, small output voltage ripple, wide application prospect and the like, a plurality of inputsources are in common ground or are in not common ground, the output filtering circuit is shared, and a key technology is laid for a large-capacity distributed power supply system for achieving combined power supply of various new energy sources.

The invention provides a digital low-dropout voltage stabilizer. The digital low-dropout voltage stabilizer comprises a power adjusting transistor, a first sampling resistor, a second sampling resistor and a pulse width modulation generation circuit, wherein a source electrode of the power adjusting transistor is connected to power voltage; a drain electrode of the power adjusting transistor is used as an output end; the power adjusting transistor is grounded through the first sampling resistor and the second sampling resistor which are connected in series; a grid electrode of the power adjusting transistor receives control signals produced by the pulse width modulation generation circuit to implement switch-on and switch-off of the power adjusting transistor; the pulse width modulation generation circuit is connected to reference voltage to realize voltage input; and the pulse width modulation generation circuit is connected to a part between the first sampling resistor and the second sampling resistor and is used for receiving sampling signals fed back by the first sampling resistor and the second sampling resistor. Compared with the correlation technique, the digital low-dropout voltage stabilizer is simple in structure, small in output voltage ripple wave, stable in performance and low in cost.

The invention provides a Sepic converter with an output current compensation branch. The converter comprises an inductor L1, an inductor L2, a capacitor C1, an N-channel MOS transistor M1, a diode D1,a capacitor Co, an output current compensation branch and a controller. In the output current compensation branch, when an N-channel MOS transistor M1 is turned off, a part of the current is shuntedfrom the inductor L1 and the inductor L2 through a port a thereof for energy storage, when the N-channel MOS transistor M1 is turned on, energy is released through a port b thereof, current is provided for the capacitor Co and a load RL, the controller adopts a soft switch controller, the switching state of the N-channel MOS transistor M1 is controlled through a port g thereof, and the working state of energy storage or release of the output current compensation branch is controlled through a port c thereof. The Sepic converter has the characteristics of low output voltage ripple and high efficiency.