73results about "Dc-dc conversion" patented technology

The invention provides a control method of a flyback converter. The control method is a control method in a mixed control mode; in other words, the flyback converter works in a non-complementation state under light loads, the clamp switch pipe on time is shortened through down conversion, and light load losses are effectively reduced through down conversion; flyback converter works in a fixed-frequency drive complementation state under heavy loads, and the clamp switch pipe on time is prolonged. Compared with the prior art, the control method has the advantages that the voltage stress of a main switch pipe and a clamp capacitor can be effectively reduced, the main switch pipe off losses can be reduced, the clamp circuit current change slope is decreased, the EMI interference is reduced, the secondary current change slope is decreased, and the longer detection reaction time is provided for synchronous rectification. Meanwhile, the working area of a magnetic core in the third quadrant is enlarged, the maximum flux density is reduced, and the size of the magnetic core is reduced.

The configurations of an interleaved flyback converter and a controlling method thereof are provided. The proposed two-phase interleaved flyback converter includes a transformer including a first primary winding having a first terminal, a first secondary winding having a first terminal, a second primary winding having a second terminal, a second secondary winding having a second terminal and a magnetic coupled core device, wherein the first primary, the first secondary, the second primary and the second secondary windings are wound therein, and the first terminal of the first primary winding has a polarity the same as that of any of the first terminal of the first secondary winding, the second terminal of the second primary winding and the second terminal of the second secondary winding so as to eliminate a ripple of a channel current of the converter.

A switching power supply apparatus includes a PFM control circuit that outputs a clock signal Set such that a switching frequency of a switching element varies in accordance with a load state. The clock signal Set determines a turn-on timing of the switching element. A reference value of a current flowing through the switching element determines a turn-off timing of the switching element. A modulation signal is applied to the turn-off timing of the switching element to modulate one of a peak value of a drain current flowing through the switching element and an on-time of the switching element. Input control is performed separately on the clock signal Set and the modulation signal. Accordingly, even when the clock signal Set and the modulation signal contribute to each other to offset each other, modulation effects are not cancelled.

Provided is a method of localizing rack-mounted computing devices, the method comprising: receiving, with a direct current (DC) power bus or via an Ethernet control network or data network, a request from a control unit for a rack computing device location; generating, with a sensor, output signals conveying information related to a location of the rack-mounted computing device; and sending, with the direct current (DC) power bus or via an Ethernet control network or data network, location information of the rack-mounted computing device.

The invention discloses a PWM/PDM double-mode modulation selecting circuit and a double-mode modulation method, which mainly solves the problem that the prior DC/DC converter is not high in average conversion efficiency within a heavy-load range. The whole circuit comprises a bias circuit, a band gap reference voltage source, an error amplifier, an isolation common-source follower, an oscillator, an integrator, a mode judgment comparator, a control comparator, a latch and a driving buffer, wherein the mode judgment comparator and the latch are connected between the output end of the error amplifier and the control end of the oscillator; the magnitude comparison of load current is converted into voltage comparison through the relation of duty cycle and triangular wave; and when the load current is larger, the circuit selects a PWM modulation mode otherwise the circuit selects a PDM modulation mode when the load current is smaller. Under the condition of guaranteeing the performance of the DC/DC converter, the invention improves the average conversion efficiency in a load change interval, and is applicable to the DC/DC switch converter with great load current change, low requirement on circuit volume and high requirement on conversion efficiency.

Asynchronous rectifier controller is provided on a secondary side of an insulation-type synchronous DC/DC converter and controls the synchronous rectifier transistor. A driver circuit controls the synchronous rectifier transistor. A photo coupler connection terminal is coupled to an input side of the photo coupler. An error amplifier amplifies an error between a voltage detection signal according to an output voltage of the DC/DC converter and its target voltage, and to draw a current according to the error from an input side of the photo coupler via the photo coupler connection terminal.

A switching constant-current power device can stabilize current flowing to a load (e.g. a display device comprising an LED, or the like) even when the current is repeatedly interrupted. A voltage current detector is connected to the output side of a power converter and creates a voltage signal in accordance with the output voltage thereof; and a feedback circuit is provided between a controller for driving the power converter and a current detector, which generates a first feedback signal in accordance with the load current. The feedback circuit comprises a signal holding unit, which outputs a second feedback signal that was created by consulting the voltage signal at a given time, the feedback circuit supplying the first feedback signal, output by the current detector, to the controller when load current is flowing, and supplying the second feedback signal, output by the signal holding unit, to the controller when load current is not flowing.

A multi-winding high step-up DC-DC converter includes a three-winding transformer to transform a low DC voltage to a high DC voltage; a power switch to control the energy flux of the primary winding of the three-winding transformer based on turning on/off the power switch; a first diode to control the current of the first secondary winding of the three-winding transformer; a second diode to control the current of the second secondary winding of the three-winding transformer; and a third diode to control the current of the primary winding. When the DC-DC converter is in the first operation state, the switch and the second diode are in on state, and the first and the third diodes are in off state. When the DC-DC converter is in the second operation state, the switch and the second diode are in off state, and the first and the third diodes are in on state.

A safe power supply circuit of the invention comprises a single-chip microcomputer control circuit, a loop protecting circuit and a voltage reducing and stabilizing power supply circuit which supplies electric power to the single-chip microcomputer control circuit. The output end of the loop protecting circuit is connected with a voltage detecting circuit. One end of the output end of the voltage detecting circuit is connected with the single-chip microcomputer control circuit, and the other end is connected with a loop switch protecting circuit. The output end of the loop switch protecting circuit is connected with a current detecting circuit. The output end of the current detecting circuit is connected with the single-chip microcomputer control circuit. The output end of the single-chip microcomputer control circuit is connected with a voltage detecting circuit. The safe power supply circuit can settle the problems of no protecting measures for overvoltage, overcurrent and reverse charging; and incapability of realizing automatic matching between a charger and an anode and a cathode of a battery. Higher safety and higher user-friendly performance of an electric vehicle are realized.

A semiconductor device includes: a semiconductor chip including a nitride semiconductor layered structure including a carrier transit layer and a carrier supply layer; a first resin layer on the semiconductor chip, the first resin layer including a coupling agent; a second resin layer on the first resin layer, the second resin layer including a surfactant; and a sealing resin layer to seal the semiconductor chip with the first resin layer and the second resin layer.

A control device for a DC-DC converter includes a PWM controller for generating a PWM signal to a switch module of the DC-DC converter according to a feedback signal of the DC-DC converter, a logic circuit for generating a selection signal according to a magnitude of an output current of the DC-DC converter, and a multiplexer coupled to a plurality of voltages for selecting one of the plurality of voltages to be a supply voltage according to the selection signal.

The invention relates to the technology of a power source and an integrated circuit, in particular to a DC-DC converter with the output voltages capable of being adjusted quickly. The DC-DC converter comprises a driving circuit, a PMOS tube MP, an NMOS tube MN, a PWM comparator, an EA amplifier, an inductor L, a capacitor C, a resistor R and a power source Vin. The DC-DC converter is characterized in that a calculating amplifier is further included, the driving circuit, the PMOS tube MP, the NMOS tube MN, the PWM comparator, the EA amplifier, the inductor L, the capacitor C, the resistor R and the power source Vin form a traditional DC-DC converter, and the positive input end and the output end of the calculating amplifier are connected to be used as one end, connected to the capacitor C, of a bumper. The DC-DC converter has the advantages of being simple in structure, easy to achieve, low in power consumption, and capable of achieving quick adjusting of the output voltages of the DC-DC converter only by small domain area. The DC-DC converter is particularly suitable for DC-DC converters.

A power conversion apparatus includes a plurality of power supply circuits each including a primary side circuit, and a secondary side circuit that is magnetically coupled to the primary side circuit via a transformer. Electrical power that changes according to a phase difference between switching of the primary side circuit and switching of the secondary side circuit is input and output to and from the power supply circuit. The power conversion apparatus includes a first power supply circuit, a second power supply circuit that uses, as an input side thereof, an output side of the first power supply circuit, and a control unit that adjusts residual power obtained by subtracting input power of the second power supply circuit from output power of the first power supply circuit, by controlling a phase difference of the first power supply circuit and a phase difference of the second power supply circuit.

The invention provides a switching power supply device capable of ensuring the transient recovery of the voltage discharge of an electrolytic capacitor after the rectifying process, without the addition of power consumption. The switching power supply device comprises a rectifying circuit used for rectifying the AC voltage; an electrolytic capacitor used for rectifying and smoothing the AC voltage; a transformer used for applying a smoothed voltage onto the electrolytic capacitor; a switching element connected to the transformer (T); and a control circuit (Z1) used for enabling the switching on/off of the switching element. The control circuit (Z1) is composed of a start-up circuit (Z10) and a discharge circuit (Z14). The start-up circuit (Z10) is used for supplying the voltage of the electrolytic capacitor to the Vcc terminal of the control circuit (Z1). The discharge circuit (Z14) is connected with the Vcc terminal and is used for discharging the transient recovery voltage of the electrolytic capacitor.

In a D.C. to D.C. converter, an input voltage is received via an inductor at an input terminal and stored onto a capacitor of an integrator. A first switch is coupled between the input terminal and a reference terminal such as ground and thereby fluxes the inductor. The input voltage stored on the capacitor falls at a rate determined by the integrator circuit and an initial value of the input voltage. After a time duration, the first switch becomes nonconductive. Current flows from the inductor through a diode to an output terminal until a second switch across the diode is made conductive. Stored voltage on the capacitor of the integrator increases in response to the second switch being conductive. The stored voltage on the capacitor is continuously compared with a reference voltage. The second switch is made nonconductive when the stored voltage on the capacitor exceeds the reference voltage.

The invention relates to a quasi-resonant push-pull converter and the method for controlling the same, said push-pull converter comprising: a direct current (DC) input power supply configured to supply DC input for the converter; a first power input unit and a second power input unit, connected to said DC input power supply, respectively and configured to supply input for the converter in different periods, comprising a first power switching tube and a second power switching tube, a first primary winding and a second primary winding; a power output circuit, configured to supply output of the converter, comprising secondary windings and full-bridge rectification circuits; a first output capacitor and a second output capacitor connected to said power output circuit and configured to store DC electric energy output by the power output circuit in which a resonant element is arranged to achieve a quasi-resonant switching circuit through voltage feedback; and a switching circuit being controlled through voltage feedback, whereby turns ratio of the primary windings and the secondary windings of the push-pull converter is controlled.

The invention discloses a voltage disturbance generation device which comprises a three-phase rectifier module. The three-phase rectifier module is connected with a three-phase chopper voltage regulation module A, a three-phase chopper voltage regulation module B and a three-phase chopper voltage regulation module C through a DC LC filter. The three-phase chopper voltage regulation module A is connected with a full-bridge inversion module A through a three-phase DC LC filter A; the three-phase chopper voltage regulation module B is connected with a full-bridge inversion module B through a three-phase DC LC filter B; and the three-phase chopper voltage regulation module C is connected with a full-bridge inversion module C through a three-phase DC LC filter C. The full-bridge inversion module A, the full-bridge inversion module B and the full-bridge inversion module C respectively have two paths of output, wherein one paths of outputs are connected with the input end of a three-phase AC LC filter, and the other paths of outputs are mutually short circuited and are connected with the three-phase AC LC filter simultaneously. The problems that continuously-changing output voltage amplitude cannot be realized in a conventional voltage disturbance generation device, and the control difficulty is high are solved; and the voltage disturbance generation device is simple in structure and easily-controlled.

The invention discloses a design method of flyback switching power supply transformer shield windings. The design method comprises the steps of (1) selecting a transformer, determining a connection type of the transformer shield windings, and measuring a structural dimension of the transformer, (2) setting turns of the shield windings as fixed values, and obtaining structural capacitance between the windings of the transformer under the different turns of the shield windings by utilizing simulation software, (3) calculating a common mode current equivalence coefficient in the transformer underthe different turns of the shield windings, and drawing a function relation characteristic curve of the common mode current equivalence coefficient and the turns of the shield windings, and (4) obtaining the turns of the shield windings when the common mode current equivalence coefficient is minimum according to the drawn characteristic curve, namely the optimal turns of the shield windings for inhibiting common mode current of the transformer. Compared with the existing common mode inhibition technique, the method has the advantages of simple device manufacturing, low realization cost, overall device weight and volume reduction, obvious inhibition effect and the like.

The invention relates to a three-port DC/DC converter for high-power charging and belongs to the technical field of automobile driving and control. The three-port DC/DC converter solves the problem that a traditional non-isolated buck topology cannot freely and simultaneously realize high-power charging and the control of the free charge-discharge requirements of a battery. An input capacitor is connected in parallel with a voltage source; the positive pole of the voltage source is connected to the drain of a switching transistor Q1; the source of the switching transistor Q1 is connected to the cathode of a diode D1; the anode of the diode D1 is connected to the negative pole of the voltage source; the source of a switching transistor Q2 is connected to the cathode of the diode D1; the drain of the switching transistor Q2 is connected to the cathode of a diode D2; the anode of the diode D2 is connected to the positive pole of a battery; the negative pole of the battery is connected tothe anode of the diode D1; one end of an inductor L1 is connected to the source of the switching transistor Q2; the other end of the inductor L1 is connected to the drain of a switching transistor Q3;the source of the switching transistor Q3 is connected to the anode of a diode D3; the cathode of the diode D3 is connected to the positive pole of the battery; one end of an output capacitor is connected to the drain of the switching transistor Q3; and the other end of the output capacitor is connected to the negative pole of the battery. The three-port DC/DC converter is suitable for automobiledriving and control.

The invention discloses a boosted circuit and a signal output method. The boosted circuit comprises a boosted module, a boosted control module, a ripple signal generation module and a voltage given signal generation module. The boosted control module carries out sampling on an inductance current signal of the boosted module and an output voltage signal. According to a ripple signal, a voltage given signal, the voltage signal and the inductance current signal, wherein the voltage signal and the inductance current signal are acquired through sampling, a driving pulse signal is generated. The boosted module completes a boost change to an input voltage signal under the control of the driving pulse signal and provides direct voltage signal output possessing a ripple component. Because the ripple signal generation module is newly added, the boosted module outputs a voltage signal possessing the ripple component. A backward-stage direct current/direct current link directly generates a jitter frequency effect because the input voltage signal possessing the ripple component so that an electromagnetic interference problem of a power supply system is alleviated.

The invention provides a step-down DC-DC converter, which further comprises an output circuit, a voltage feedback circuit, a discharge path and a discharge control circuit, wherein the output circuitis used for converting an input voltage into an output voltage, and comprises a first power transistor and a second power transistor which are connected in series between an input end and a groundingend; the voltage feedback circuit is used for acquiring a feedback voltage based on the output voltage; the discharge path is coupled between the output circuit and the grounding end and is controlledin discharging; and the discharge control circuit controls the discharge path to discharge the output circuit when the feedback voltage obtained by the voltage feedback circuit is greater than a second reference voltage and the first power transistor is cut off, and controls the discharge path to prohibit discharge when the feedback voltage obtained by the voltage feedback circuit is smaller thanthe second reference voltage or the first power transistor is conducted. In this way, the problem that the overshoot duration of large-current transient response is long can be solved.

The invention discloses a DC transformer based on a centralized multi-winding high-frequency transformer, and a control method of the direct-current transformer. The transformer comprises M DC transformer units with input ends connected in series and output ends connected in parallel, wherein the medium-voltage DC side input ports of the M DC transformer units are connected in series to form a medium-voltage DC side port of the DC transformer, and low-voltage DC side output ports of the M DC transformer units are connected in parallel to form a low-voltage DC side port of the DC transformer. The multi-winding high-frequency transformers among the DC transformer units are mutually independent; each DC transformer unit comprises N submodules, the inputs of which are connected in series and the outputs of which are connected in parallel, wherein N is greater than or equal to 3; the input filter capacitors Cini of the submodules are connected in series to form a medium-voltage DC side input port of the unit, and the output filter capacitors Coi are connected in parallel to form a low-voltage DC side output port of the unit. According to the transformer, the bidirectional transmission of power between the medium-voltage DC side and the low-voltage DC side can be realized by controlling a phase shift angle between primary and secondary side bridge arms of the transformer in each sub-module, and zero-voltage switching-on of all switch tubes is realized.

The invention relates to the field of power management, and provides a Buck type high power factor converter based on an integrated controller. In order to achieve high power factors, according to the technical scheme, the Buck type high power factor converter based on the integrated controller comprises a peripheral circuit, a rectifying bridge is composed of four diodes, and a partial voltage structure which is formed by two resistors which are in series connection is connected to the rear portion of the rectifying bridge in parallel; the positive output end of an AC input power source is connected to the negative electrode of one diode, the negative output end of the AC input power source is connected with an MOS switch through a current detecting resistor, and the other end of the MOS switch is connected with the positive electrode of the corresponding diode. The positive electrodes of the diodes are connected with one end of a voltage reduction inductor. An output load is connected with a difference partial voltage structure in parallel. Middle nodes of the two resistors are connected to the base electrode of a P-type audion, a high level end is connected to the emitting electrode of a secondary audion after passing through an emitting electrode resistor, a collector electrode is connected to the ground after passing through a collector electrode resistor, and a node between the collector electrode and the resistors outputs voltage feedback signals. The Buck type high power factor converter based on the integrated controller is mainly suitable for power source management.

The invention relates to a circuit for realizing constant current control in a primary control switch power converter. The circuit comprises a controller, wherein the controller comprises a sampling/holding circuit, a voltage/current conversion circuit, an oscillator circuit, a flip-flop and a current limiting comparator; the sampling/holding circuit samples and holds feedback voltage VFB and inputs the feedback voltage VFB to the voltage/current conversion circuit; the voltage/current conversion circuit converts the feedback voltage VFB to obtain required control current; the oscillator circuit outputs a corresponding oscillation frequency signal according to the control current, and inputs the oscillation frequency signal to a setting end of the flip-flop; when the oscillation frequency signal is at a high level, an output ends of the flip-flop outputs a high level signal to switch on a driving power tube; and when sampling voltage VCS is higher than reference voltage VREF of an antiphase end of the current limiting comparator, the current limiting comparator outputs a current limiting signal to allow the flip-flop to output a low level so as to switch off the power tube. The circuit is compact in structure, wide in application scope, safe and reliable, and can realize the constant current control.

The invention relates to a current-type reduced matrix converter which includes a three-phase input power supply, an input filter, a matrix chopper, a high-frequency transformer, a current chopper, anoutput filter, and a load. The output ports R, S, T of the three-phase input power supply are correspondingly connected with the input ports R0, S0, T0 of the input filter. The output ports r1, s1, t1 of the input filter are correspondingly connected to the input ports r2, s2, t2 of the matrix chopper. The primary ports A, B of the high-frequency transformer are correspondingly connected with theoutput ports A0, B0 of the matrix chopper. The secondary ports a, b of the high-frequency transformer are correspondingly connected to the input ports a0, b0 of the current chopper. The output portsw, v of the current chopper are correspondingly connected with the input ports w0, v0 of the output filter. The output ports w1, v0 of the output filter are correspondingly connected with the ports w2, v2 of the load. The invention further discloses a control method of the converter. The current-type reduced matrix converter has excellent performance and high efficiency.

A charge pump control circuit that four main parts: a clock control circuit; a clock switch and driver circuit; a pump stage; and a dynamic load control circuit. The clock control circuit has a dynamic load that is controlled by the dynamic load control circuit. When the charge pump control circuit is enabled, the dynamic capacitive load is applied which incorporates a delay allowing the high frequency clock to control the pump stage and quickly charge the output to the desired boosted voltage. This provides a very fast boosted output voltage during a startup condition. Once the desired output voltage is realized, the dynamic capacitive load is disabled and the low frequency clock takes over the operation. During each low frequency clock cycle, the high frequency clock is enabled for several cycles per cycle of the low frequency clock.