214results about How to "Small output ripple" patented technology

The invention discloses a high-power direct-current charging machine / pile DCDC conversion device for an electric automobile and a control method of the high-power direct-current charging machine / pile DCDC conversion device. A multiphase interleaving voltage decrease and increase adjustment technology is adopted in the device, the requirements for adjustment of wide voltage input and wide voltage output are met, and through the modularized control structure design, the output of charging energy can be controlled, the output ripples can be reduced, and power and efficiency are improved. The output voltage and the current of the device can both be controlled, and the device has the protection functions of current protection, voltage protection, temperature protection, power protection, drive short circuit protection and the like; and a pre-starting current limiting module, a charging pre-starting and discharging protection module, a hardware overcurrent protection module and a fault signal processing module are additionally arranged, so that the safe reliability of the device is effectively enhanced. The device is small in ripple, high in conversion efficiency, low in cost, simple in structure, small in start current and high in safe reliability, the device can be used for high-power direct-current charging machine / pile DCDC power conversion for the electric automobile and also be used for other power and power supply equipment, and the device is suitable for being used in various power and electronic fields.

This invention relates to three-level switch power amplifier belonging to voltage to current switch power amplifier, which comprises Signal mixture process circuit, impulse modulation circuit, protective and light coupling drive circuit and the voltage signal drive bridge circuit to control the signal to get relative voltage signals to control the load current size. The double electrode power amplifier without bias current has wide application prospect.

The response ability to the transient change of the load is an important indicator of the LDO performance of the low dropout voltage regulator. The present invention learns from the loop control method of the charge pump type phase-locked loop, discloses a low output voltage fast response LDO structure based on the current control loop, the feedback voltage is converted into current, and the current signal is used as the carrier in the control loop. Operation, the difference current is integrated by the loop filter to form the control voltage of the power tube. Low-dropout regulators based on current control loops respond well to load transients and can produce voltage outputs lower than typical bandgap reference voltages. The fast-response LDO circuit based on the current control loop disclosed by the invention is composed of a voltage buffer, a transconductance amplifier, a loop filter, a power tube and an off-chip load.

The invention provides a switched capacitor DC-DC converter. The switched capacitor DC-DC converter comprises an output sampling branch, a dead area control module for generating the dead area and outputting multiunit clock signals which has the same frequency as the input clock, a switched capacitor array module for receiving multiunit clock signals which are not overlapped and sent by the dead area control module, an error amplifier for receiving the voltage signal from the output sampling branch and the reference voltage signals, and a voltage controlled oscillator for receiving the output voltage signals of the error amplifier and for outputting the clock signals with corresponding frequency. The voltage controlled oscillator sends the clock signals to the dead control module. The frequency variation of the clock signals is in proportion to the output voltage variation of the error amplifier. The converter has low output voltage ripple and high efficiency in full load range.

An abnormality detection apparatus of a vehicle AC generator that includes a rectifier for providing DC voltage is disclosed. The abnormality detection apparatus includes an abnormality judging unit and an alarm lamp. The abnormality judging unit judges abnormality of the vehicle AC generator if the number of ripples that is included in the output voltage of a rectifier is not equal to or more than a predetermined number for a predetermined period. The alarm lamp lights when the abnormality judging unit judges abnormality.

The invention discloses a high-power bidirectional multi-way direct-current simulation power supply. The high-power bidirectional multi-way direct-current simulation power supply is characterized by consisting of at least two mutually insulated simulation direct-current power supply units, wherein each simulation direct-current power supply unit comprises an AC / DC converter and a DC / DC converter which are connected in series; an input end of each AC / DC converter is connected with a secondary side winding of an input transformer; an input end of each DC / DC converter is connected with a capacitor in parallel, and a positive electrode of an output end of each DC / DC converter is connected with a diode in series; two ends of each diode are respectively connected with a switch in parallel. The high-power bidirectional multi-way direct-current simulation power supply is universal in function, only needs to adopt different control strategies, can widen the functions without replacing hardware, and solves the problems of high testing cost of existing DC equipment, small capacity, difficulty in expansion, single voltage level and functions and the like.

The invention provides a band-gap reference source circuit with a stable low-offset and low-noise noise chopped wave, comprising an operational amplifier, a transistor arranged in the form of a mirror image and a divider resistor, wherein a modulator is connected in front of an input end of the operational amplifier while an output end of the operational amplifier is connected with a demodulator; an output end of the demodulator is connected with an input end of a RC low-pass filter; an output end of the RC low-pass filter is connected with an input end of a buffer; a transmission gate circuit is connected between two input ends of the buffer; another input end of the buffer is connected with an input end of another RC low-pass filter; and an output end of the RC low-pass filter is connected with an output end of the buffer. By using the invention, a signal is modulated at the input end of the operational amplifier and demodulated at the output end. The demodulated input signal is recovered while an equivalent offset voltage and 1 / F noise are modulated to a high frequency and then filtered by the low-pass filter, thereby reducing or even eliminating the influences of the offset voltage and the 1 / F noise on the precision and successfully solving the phenomenon of low output voltage precision caused by the offset voltage of the operational amplifier.

The invention discloses a phase shift compensation interleaved three-level LLC resonant converter, and belongs to the technical field of power electronic converters. The converter includes an input power supply, two three-level LLC resonant circuits, two center-tapped transformers, two rectifier circuits, and an output circuit; and each three-level LLC resonant circuit comprises an input voltage dividing capacitor, a switch bridge arm and a resonant cavity which are connected in sequence. The converter provided by the invention can achieve a wide range of inputs, and also can compensate for the unsynchronized switching frequencies of the two circuits due to parameter errors by adjusting the duty cycle via the phase shift adjustment module. The two circuits are enabled to work at the same switching frequency without adding any auxiliary circuit through the interleaved structure, the output ripple is reduced, the converter efficiency is improved, and the service life of the power supply is prolonged.

The invention discloses a wide-voltage-input efficient direct-current power converter for an aerostat. The wide-voltage-input efficient direct-current power converter comprises a SuperBuck circuit, a push-pull circuit, a closed-loop control circuit and a diode used for achieving the series connection of the output end of the SuperBuck circuit and the output end of the push-pull circuit, wherein the SuperBuck circuit is composed of an inductor, a capacitor, a diode and a switch tube, and the push-pull circuit is composed of a switch tube, a boosting transformer, a rectifier diode and a filter capacitor. The wide-voltage-input efficient direct-current power converter for the aerostat has the advantages that the polarity of input voltages and the polarity of output voltages are identical, a main circuit device is simple, input currents and output currents are consecutive, input and output are common-grounded, current pulses caused to a power supply bus and a storage battery are small, and smooth switching of voltage boosting and voltage reduction can be achieved.

The invention relates to an adjustable integrated high-voltage grid electrode pulse modulator. An improved design is conducted on a filament high potential power supply circuit, a positive biased high potential power supply circuit, a negative biased high potential power supply circuit and a grid electrode pulse modulator circuit, and the high dense integration of the three high potential power supply circuits and the grid electrode pulse modulator circuit is achieved; a feedback circuit of a high potential power supply is improved, a magnetism feedback high voltage isolation sampling technology is adopted, and respectively independent adjustment to the high potential power supply output voltage values is achieved at the low voltage side; a high potential integrated failure detecting circuit is added, and the high potential power supply multi-circuit failures are integrated into one circuit signal; a pulse driving circuit is improved, and a dual-level denoising circuit is added; a grid electrode floating plate modulating circuit is improved, and an fire-making resistance protection circuit protection modulator and a traveling wave tube are added; a high-voltage transformer structure used for the modulator is improved, the size is reduced, and high-voltage isolation is achieved.

The invention provides a synchronous buck DC-DC converter capable of achieving low output ripples in times of underloading. A frequency-down circuit is additionally arranged on the structural basis of the synchronous buck DC-DC converter, and accordingly the problem of being large in output ripple in times of underloading is mainly solved. The frequency-down circuit comprises a transconductance amplifier and a clock circuit. The transconductance amplifier is used for detecting whether the output end of the DC-DC converter is underloaded or not, the clock circuit lowers the frequency of clock signals CLK in times of underloading, and the output ripples in times of underloading are greatly reduced while a feedback circuit has enough time to adjust input power so as to be adapted to change of output loads and to improve underloading efficiency of the converter. The application range of the converter is widened, and the performance of the converter is improved.

The invention belongs to the technical field of switching power supply, and particularly relates to a PFM control method of a switching power converter and a realizing device thereof. The method comprises the following steps: detecting the partial voltage value of the output voltage, comparing the rising edge with VREF in each clock cycle, and if the rising edge is lower than VREF, enabling a power-level switching tube to conduct a signal with fixed duty cycle by using a control logic circuit and a power driving circuit; and if the rising edge is high than VREF, skipping the cycle. Meanwhile, the current detection circuit detects a load current and compares the load current with preset threshold, and a current interval judging device selects the appropriate dimensions of the power tube according to the detection current and controls the segment selector to select the segmented power level, thereby realizing an optimal PFM control. The optimal PFM control can keep high efficiency and reduce the ripples of the output voltage, as well as prevent the switching frequency of the system from entering the audible range.

The invention discloses a high-speed high-definition CMOS imaging system. The system comprises a lens, a CMOS camera and a computer. The CMOS camera comprises a power supply unit, a CMOS sensor chip, a FPGA control unit, a high speed data memory cell, a CameraLink interface unit, a parameter memory cell and an upper computer interface unit. Through using a high-speed high-definition CMOS chip, a 1280*1024 resolution of the CMOS camera is realized; through using a DDR3 high speed image memory cell, high speed image data is stored in real time, a storage capacity is increased, a data transmission bandwidth is increased too, and during the 1280*1024 resolution, a work speed whose frame frequency is 1000 frame / second is realized; through using a DC-DC power supply and a LDO power supply to provide power, a system noise is small, power consumption is low and imaging quality is good; and through using a CameraLink interface to transmit image data, real-time image display below 400 frame / second (the resolution is 1280*1024) can be realized, and a high-speed high-definition shooting requirement is satisfied. Besides, the system can configure parameters of a work mode and the like of a CMOS detector through an upper computer, and usage is simple and convenient.

The invention discloses a constant current driver of a light emitting diode. The constant current driver comprises a single stage PFC (power factor correction) circuit, an adjusting tube and a control unit, wherein an input end of the single stage PFC circuit is connected with a power supply; the light emitting diode and the adjusting tube are connected in series between a first output end and a second output end; the anode of the LED is connected with the first output end; the cathode is connected with a first end of the adjusting tube; a second end of the adjusting tube is connected with the second output end of the single stage PFC circuit; the control end is connected with the control unit; the control unit can control the current flowing through the adjusting tube to be stabilized, so that the load characteristic of the connection of the single stage PFC circuit is changed, a load current wave of the single stage PFC circuit is reduced, so the error that output signals of the single stage PFC circuit are fed back to an input end of a closed control circuit is reduced, the error of a reference signal of a current control input end in the single stage PFC circuit is reduced as well, and power factors of the single stage PFC circuit are increased ultimately.

This invention provides one positive and negative voltage conversion circuit, which comprises the following parts: one dropping switch mode adjustor; electrolyte capacitor, diode, output memory induction, electrolyte capacity, high frequency filter capacitor, feedback resistance network, output filter induction and electrolyte capacity. This invention adopts filter induction to eliminate voltage beam wave and load ability resulted by Buck-Boost circuit and put filter induction on negative end.

The invention relates to a LLC circuit which comprises an inverter circuit, a resonance circuit, a transformer and a rectifier circuit, wherein the inverter circuit, the resonance circuit, the transformer and the rectifier circuit are connected in turn. Both ends of a secondary winding of the transformer are connected with the rectifier circuit to form first voltage output. A tap is arranged between both ends of the secondary winding of the transformer. The tap and one of both ends of the secondary winding of the transformer are connected with rectifier circuit to form second voltage output. The transformer adopts a segmented design. The output voltage of a power supply can be divided into a high voltage section and a low voltage section. By changing the turn ratio, the LLC circuit respectively works in two small voltage ranges. The work frequency f of the power supply can change in a small range near respective resonance frequency points fr and fr2, and less deviation is produced, thus the loss can be greatly reduced. The LLC circuit can easily start a continuous mode, which greatly reduces the output ripple.

The invention relates to a modular power supply for insulating fixed symmetrical output high voltage, which comprises a power supply circuit encapsulated in a casing. The power supply circuit is welded with a plurality of guide pins; the power supply circuit comprises a control and drive circuit, a high voltage feedback circuit and a symmetrical high voltage rectifying and filtering and output circuit; the control and drive circuit is connected with the high voltage feedback circuit through the symmetrical high voltage rectifying and filtering and output circuit; and the high voltage feedback circuit is connected with the control and the drive circuit. The modular power supply has the advantages that input is completely insulated with output, and two paths output high voltage symmetrically; the temperature drift is small, and the output ripple is low; under the condition of fixed load, high voltages output by the two paths have better symmetry and good long-term stability; and the modular power supply has small external size, small weight and easy PCB installation.

The invention provides a high-performance digital self-calibration chopper precision amplifier which is low in cost and easy to implement and an implementation method. The amplifier mainly comprises a digital self-calibration loop and a chopper circuit. After the amplifier is energized, the amplifier is configured as a digital self-calibration state within a period of time, and the chopper circuit and an amplifier output circuit are switched off. The calibrated digital quantity is stored in a register, and input offset voltage of the amplifier is calibrated through a digital analog converter. After the digital self-calibration state is finished, a comparison output circuit is switched off, the amplifier is configured as a chopper magnifying state, and the chopper circuit and the amplifier output circuit work, so that the input offset voltage of the amplifier, temperature drift of the offset voltage and flicker noise are lowered.

The invention discloses a gain self-adaption error amplifier comprising a level shift circuit, an operation transconductance amplification circuit and a comparison circuit. An input level of the operation transconductance amplification circuit meets a normal operation requirement by the level shift circuit; the operation transconductance amplification circuit uses a bipolar audion as a differential pair transistor, and utilizes an MOS tube common-source structure current mirror to provide current bias for the differential pair transistor to reduce power consumption, so as to ensure providing of greater gain; the comparison circuit utilizes a feedback structure to control a circuit output slew rate, so as to output a control signal of the operation transconductance amplification circuit; an amplitude limiting circuit limits the output voltage of the operation transconductance amplification circuit. According to the amplifier provided by the invention, power output ripples in a load current stabilization application are reduced, and thus power consumption of a system is reduced, and meanwhile influence on a load transient behavior is small.

The invention relates to a fixed-output isolation high-voltage power supply module, which is applied in an instrument and equipment for mass spectroscopy, solid surface analysis, high-energy physics detection, semiconductor component testing systems, environmental monitoring, dust particle counters, medical application and the like. The fixed-output isolation high-voltage power supply module comprises a power supply circuit enclosed in a shell, the power supply circuit is welded with a plurality of lead pins and comprises an oscillation and control circuit, a drive circuit, a high-voltage sampling and feedback circuit and a rectification filter circuit, wherein the oscillation and control circuit is connected with the rectification filter circuit through the drive circuit, and the rectification filter circuit is connected with the oscillation and control circuit through the high-voltage sampling and feedback circuit. The invention has the advantages of complete separation of input and output, low temperature drift, high stability, low output ripple, good long-term stability, small contour size, light weight and easy PCB installation.

The invention discloses an isolated parallel CUK push-pull topology. A positive electrode of an input DC power supply U<1N> is simultaneously connected with a drain of a power electronic switch T1 and a dotted end of a primary winding N12 of a transformer TR, a non-dotted end of the primary winding N12 is simultaneously connected with a drain of a power electronic switch T2 and one end of a capacitor Ci, the other end of the capacitor Ci is simultaneously connected with a non-dotted end of a primary winding N11 of the transformer TR and a source of the power electronic switch T1, a dotted end of the primary winding N11 is simultaneously connected with a source of the power electronic switch T2 and a negative electrode of the input DC power supply U<1N>, a secondary winding N2 of the transformer TR supplies power to a load, and the power electronic switch T1 and the power electronic switch T2 both employ GaN transistors and are controlled to be alternatively conducted or cut off by an input control pulse. The topology is isolated, has good electric shock prevention safety, can output alternating current and is small in input ripple and output ripple, the problem of DC magnetic biasing can be solved, the negative influence of leakage inductance can be overcome, and the power efficiency can reach 0.95 or above.

The invention provides a photovoltaic micro inverter. The photovoltaic micro inverter comprises a voltage boosting module and an inversion module, wherein the voltage boosting module comprises a front-stage DC-DC converter and a post-stage DC-DC converter; and a photovoltaic array (PV), the front-stage DC-DC converter, the back-stage DC-DC converter and the inversion module are connected in series in sequence. The front-stage DC-DC converter adopts a Cuk circuit to realize the highest-power-point tracking and voltage boosting; the post-stage DC-DC converter is used for further boosting the voltage to achieve the level of a power grid; and the highest-power-point tracking is realized as well when the voltage-boosting ratio is greater than 10. According to the photovoltaic micro inverter, the circuit characteristic of low switching loss is taken into full play; the high-frequency characteristic of a switching capacitive circuit is fully utilized; and the size and the output ripple of a filter can be effectively reduced.

The invention discloses a double-period conversion circuit for energy acquisition. The double-period conversion circuit comprises two stages, wherein the first stage is a negative pressure converter, the second stage is an active diode, the negative pressure converter is used for converting negative amplitude of an AC signal of a sensor to positive amplitude, a P-channel metal oxide semiconductor (PMOS) adopts a substrate bias design and is used for reducing the conduction resistance, and the active diode adopts a common-gate comparator structure and is used for reducing a power supply voltage of a system on the basis of ensuring the gain and bandwidth. The double-period conversion circuit aims to reduce the number of comparators, reduce the working voltage and the power consumption of the overall circuit and improve the voltage conversion efficiency and the energy conversion efficiency, and the requirements of a micro energy acquisition system for low voltage and low power consumption are met. By reducing the working voltages of the comparators, the overall working voltage is reduced, so that the circuit is applicable to the energy acquisition system; by the adoption of the two-stage rectification structure, the number of the comparators is reduced, the overall power consumption is reduced, and the energy conversion efficiency is improved; and the energy loss in open-circuit time is reduced through double-period control.

A DC / DC conversion apparatus includes a DC voltage source, an oscillation circuit being electrically connected to the DC voltage source, a plurality of switch elements, a switch controller, which closes or opens electrical connection between the DC voltage source and the oscillation circuit by switching turn-on and turn-off of the plurality of switch elements, and switches a direction of a voltage applied on the oscillation circuit between a first direction and a second direction, a transformation circuit, a detector to detect one or more parameter values of an input voltage and input current of the DC voltage source and an output voltage and output current to the transformation circuit, wherein when the parameter values vary, the switch controller adjusts a length of time in which the voltage applied on the oscillation circuit is in one of the first direction and the second direction, such that the output voltage and / or output current returns to an initial value.

A non-isolated type switching regulator having an inductor includes: a switch element; a rectification element; an error amplifying circuit section amplifying a voltage difference between a feedback voltage and a first reference voltage and outputting as an error voltage; a first voltage comparison circuit section performing a voltage comparison of a ramp voltage which performs a voltage change set beforehand with the error voltage to be synchronized with the switching of the switch element and producing and outputting a first comparison signal; a second voltage comparison circuit performing a voltage comparison of the error voltage with a second reference voltage and producing and outputting a second comparison signal; an oscillation circuit section starting an oscillation based on the second comparison signal and producing and outputting a clock signal; and a control circuit section performing a switching control of the switch element based on the clock signal and the first comparison signal.

The present invention provides a linear electric power source which outputs low ripple voltage and is used for audio equipment and other equipment that has low requirement to the output ripple voltage, wherein, the linear electric power source comprises an industrial frequency transformer, a commutating wave filtering circuit, a voltage regulator circuit, an output circuit, a panel indicating board and a voltage converting switch. The signal of the power supply circuit is inputted from AC and is transferred through the industrial frequency transformer and the commutating wave filtering circuit, is transferred through the voltage stabilizer to the output circuit, and at the same time is sampled to the panel for indicating; wherein two circuits directly output AC alternating current after the voltage releasing of the industrial frequency transformer. The linear electric power source adopts two annular industrial frequency transformers which are fixed on the casing by screws, and the structure of the electric power source is compact. The linear electric power source adopts one part of paster and is a novel-designed linear electric power source.

The invention discloses a high-power high-frequency switching power supply module and a device. The high-power high-frequency switching power supply module comprises an alternating-current input port,a rectifier bridge module, a power factor correction circuit, an LC filter circuit, at least one high-frequency DC / DC conversion module, an output filter capacitor, an output current sensor, a direct-current output port and a control module. The high-frequency DC / DC conversion module is composed of a high-frequency inverter bridge, a resonant inductor, a resonant capacitor, a high-frequency transformer, a high-frequency rectifying circuit, a high-frequency filtering capacitor and a current transformer. The input ends of N high-frequency DC / DC conversion modules are connected in parallel, andthe output ends of N high-frequency DC / DC conversion modules are connected in series or in parallel. The power supply module is simple in overall structure, can achieve high-power, low-ripple and low-load effect output, and can solve the technical problems that some equipment power supplies cannot meet the requirements of high power, high efficiency, high power factor, high power density, low output ripple, and being easy to replace and maintain at the same time.