Class / Patent application number | Description | Number of patent applications / Date published |
363210030 | Having particular zero-switching control circuit (e.g., for quasi-resonant converter, etc.) | 57 |
20080239763 | METHOD AND APPARATUS FOR QUASI-RESONANT CURRENT MODE POWER CONVERSION - A method and apparatus to magnetically couple AC power from the high voltage electric utility power line current induced magnetic field over a wide voltage and current range to provide a low voltage, low current DC power supply useful in powering other remotely located or limited accessibility circuitry requiring low voltage DC power to operate. | 10-02-2008 |
20080259648 | Switching Control in DC-DC-Converters - Implementations related to controlling of a switch in a DC-DC converter are presented herein. | 10-23-2008 |
20080259649 | Switched mode power supply comprising a rectifier circuit - The switched mode power supply comprises an inductor, a switching transistor coupled in series with the inductor, and a rectifier circuit. The rectifier circuit comprises a switch coupled with the inductor for a rectification of an output voltage and a control circuit operating in a monostable mode. The switch is operated in particular in a synchronous mode with the same switching frequency as the switching transistor. The rectifier circuit can be used advantageously with a switched mode power supply having a push-pull half-bridge configuration and operating as a resonant converter or a quasi-resonant converter with soft switching for an application within a plasma television set. | 10-23-2008 |
20080278971 | Forward-forward converter - A forward-forward converter (FFC) and method of operation thereof. The FFC has a first transformer, including a primary winding coupled to power and clamp switches and a secondary winding coupled to the primary winding, configured to provide an output energy transfer of the forward-forward converter during conduction of the power switch. The FFC also has a second transformer, including an input winding coupled to the secondary winding, configured to form an intermediate circuit mesh and extend zero-voltage switching opportunity and the output energy transfer, through the outputs windings coupled to the input winding, during conduction of the power and clamp switches. | 11-13-2008 |
20090207635 | Standby Operation of a Resonant Power Convertor - A control method is proposed that enables to drive a resonant (LLC) power converter at low loads with substantially reduced power losses for realizing a stand-by power. The reduction is achieved by a sub-critical operation several times below Resonance Frequency while still keeping zero voltage switching. One half-bridge switch (s | 08-20-2009 |
20090310387 | DUTY-CYCLE-CONTROLLED HALF-BRIDGE RESONANT CONVERTER - A half-bridge resonant converter including a half-bridge switching circuit, a resonant circuit and a rectifier circuit is provided. The half-bridge switching circuit is controlled by two control signals for alternatively coupling two terminals of a DC power source to an input of a resonant circuit. The control signals have the same frequency and duty cycle, and one of the control signals is delayed a period by the other one, in which the frequency of the control signals is constant and the duty cycle of the control signals is variable according to a load. The rectifier circuit generates an output voltage across the load from an output of the resonant circuit. Therefore, the resonant converter of the present invention has the advantage of constant frequency operating and at least one of the two switches operated in ZVS. | 12-17-2009 |
20100020569 | RESONANT SWITCHING POWER CONVERTER WITH ADAPTIVE DEAD TIME CONTROL - A resonant switching power converter having adaptive dead time control provides improved efficiency along with reduced EMI/audible noise and component stresses. A dead time between pulses generated by a switching circuit is adaptively set in conformity with a value of the input voltage to the resonant switching power converter and an indication of a magnitude of the current passing through inductive element of the resonant tank of the converter. The indication of the current magnitude may be the switching frequency of the converter, or a measure of line or load current levels. The dead time can be obtained from a look-up table or computed from the current magnitude and input voltage values. | 01-28-2010 |
20100135049 | CONTROL CIRCUIT FOR A SWITCH UNIT OF A CLOCKED POWER SUPPLY CIRCUIT, AND RESONANCE CONVERTER - A control circuit for a switch unit of a clocked power supply circuit, the switch unit being designed to effect input-side excitation of a resonant transformer arrangement, comprises an input for receiving an auxiliary signal from the resonant transformer arrangement. The auxiliary signal exhibits an essentially fixed phase relation to a load alternating current flowing through a resonant circuit of the transformer arrangement. The control circuit further comprises a phase detector designed to detect reference crossing moments when the auxiliary signal crosses a predefined reference value, a driver controllable to switch the switch unit, and a synchronization means designed to synchronize a turn-on of the switch unit by the driver with regard to a phase position with the auxiliary signal so as to achieve a turn-on of the switch unit within a predetermined time interval around a zero crossing of a voltage present across the switch unit, or of a current flowing through the switch unit. The synchronization means is further designed to receive information about the reference crossing moments from the phase detector, and to provide a turn-on signal to the driver with a fixed phase delay at the reference crossing moments, so as to define turn-on moments at which the driver is to turn on the switch unit. The control circuit further comprises a detector designed to determine an amplitude information which depends on an amplitude or a mean value of the auxiliary signal, and a regulator designed to change an operating frequency in dependence on the amplitude information supplied by the detector, and to determine a period duration between turn-off moments at which the driver is to turn off the switch unit as a reciprocal of the operating frequency. An inventive resonance converter enables independent control of frequency and turn-on moments, or duty cycle, and thus enables a particularly efficient operation of the resonance converter, and a particularly precise regulation. | 06-03-2010 |
20100188871 | SYNCHRONOUS RECTIFIER NETWORK UNIT CIRCUIT AND METHOD - A synchronous rectifier network unit and synchronous rectifying method. The synchronous rectifier network unit includes a first body diode to which a first current flows at a first time when the first current flows to a first coil, and a first transistor which is turned on after the first body diode is conducted, and to which the first current flows, and it rectifies the first current by differently controlling the turn-off time of the first transistor according to the first current. | 07-29-2010 |
20100284203 | CONTROL MODE FOR ZVS CONVERTER AT RESONANT OPERATING FREQUENCIES - A zero volt switching voltage converter comprises a switching network including a plurality of switches for generating control signals responsive to an input voltage source and switching control signals. Circuitry generates a regulated output voltage responsive to the control current. Control circuitry generates the switching control signals wherein the switching control signals operate the plurality of switches at a resonant frequency of the zero volt switching voltage converter. | 11-11-2010 |
20100296318 | System and Method for Ringing Suppression in a Switched Mode Power Supply - In one embodiment, a method of operating a switched-mode power supply having a switch coupled to a drive signal is disclosed. The method includes shutting off the switch with the drive signal at a first instance of time, and comparing a magnitude of a voltage of a power supply node to a threshold after shutting off the switch. If the magnitude of the voltage of the power supply node exceeds the threshold, the switch is inhibited from turning on for a first time interval. | 11-25-2010 |
20100328969 | RESONANT POWER CONVERTER COMPRISING A MATCHED PIEZOELECTRIC TRANSFORMER - The present invention relates to an electronic power converter comprising a piezoelectric transformer, a drive circuit arranged to generate and provide an input voltage signal to the piezoelectric transformer, said input voltage signal comprising a burst frequency and a substantially constant excitation frequency, and a rectifier module. According to the present invention the excitation frequency is selected among a plurality of excitation frequencies in such a way that an equivalent load resistance, Req, is matched to an output impedance of the piezoelectric transformer so as to minimize power losses in the piezoelectric transformer. Moreover, the present invention relates to a method for configuring an electronic power converter. | 12-30-2010 |
20110007528 | METHOD FOR CONTROLLING A SWITCHING DEVICE OF A RESONANT POWER CONVERTER, ESPECIALLY IN ORDER TO PROVIDE A REQUIRED POWER, ESPECIALLY FOR AN X-RAY GENERATOR - This invention relates to a method for controlling a switching device ( | 01-13-2011 |
20110085355 | CONTROL DEVICE FOR RESONANT CONVERTERS - A control device for a switching circuit of a resonant converter having a direct current at the output, the switching circuit having at least one half bridge of at least first and second transistors connected between an input voltage and a reference voltage. The half bridge is adapted to generate a periodic square wave voltage to drive the resonant circuit of the resonant converter; The control device has a circuit to proportionally generate a first voltage to a switching period, and a circuit adapted to limit the voltage at the ends of a capacitor between a reference voltage and the first voltage, and a further circuit structured to control the switching off of a first or second transistor at the time instant in which the voltage across the capacitor has reached the first voltage. | 04-14-2011 |
20110157920 | CHARGE-MODE CONTROL DEVICE FOR A RESONANT CONVERTER - A control device for a resonant converter includes a first circuit structured to rectify a signal indicating the current circulating in the primary winding, a second circuit adapted to integrate at least the rectified signal and structured to generate at least a control signal of the switching circuit according to the integrated signal, and a third circuit adapted to send a reset command to the second circuit so as to inhibit the operation over a time period between the instant when the integrated signal reaches or exceeds a first signal and the instant of the next zero crossing of the signal, indicating the current circulating in the primary winding. | 06-30-2011 |
20110305048 | ACTIVE-CLAMP CIRCUIT FOR QUASI-RESONANT FLYBACK POWER CONVERTER - An active clamp circuit for a QR flyback power converter according to the present invention comprises an active-clamper connected to a primary winding of a power transformer of the QR flyback power converter in parallel. A high-side transistor driver is coupled to drive the active-damper. A charge-pump circuit is coupled to the high-side transistor driver to provide a power supply to the high-side transistor driver in accordance with a voltage source. A control circuit generates a control signal coupled to control the high-side transistor driver. The control signal is generated in response to a PWM signal and an input voltage of the QR flyback power converter. | 12-15-2011 |
20120033454 | SWITCHING POWER SUPPLY APPARATUS - A resonance-type power supply is provided in which no short circuit occurs and driving is performed with a constant switching period by performing switching control using a change of magnetic flux of a magnetic component as a trigger. When the change of magnetic flux of the transformer is detected, the first switching control signal is caused to transition to the Hi level. The detection voltage signal is A/D-converted, a first on-time is determined from the level thereof, and a second on-time is calculated by subtracting the first on-time from the constant switching period. When the first switching control signal is caused to transition to the Low level based on the first on-time, the change of magnetic flux of the transformer is detected, and the second switching control signal is caused to transition to the Hi level and is caused to transition to the Low level after the second on-time has elapsed. | 02-09-2012 |
20120033455 | SWITCHING POWER SUPPLY APPARATUS - In a switching power supply apparatus, a comparator outputs a first determination criterion signal based on a saw-tooth wave signal whose level fluctuates with a constant period and a detection voltage signal. An inverter subjects the first determination criterion signal to reverse processing, and outputs a second determination criterion signal. The comparator outputs a first switching judgment-use signal from a monitor signal and a threshold value, and the comparator outputs a second switching judgment-use signal from the monitor signal and the threshold value. An AND circuit outputs the first switching control signal from the first determination criterion signal and the first switching judgment-use signal, and the AND circuit outputs the second switching control signal from the second determination criterion signal and the second switching judgment-use signal. | 02-09-2012 |
20120044722 | ISOLATED SWITCHING CONVERTER - The isolated voltage step-down switching DC-DC converter has one magnetic component, the isolation transformer, and two small size resonant inductors. The transformer is built on a magnetic core with no air-gap, hence no DC storage and thus results in fast load transient response. Two active switches on the primary side have voltage stresses equal to input voltage and two current rectifiers on secondary side have voltage stresses equal to output DC voltage under all operating duty ratio conditions. The converter operates with two independent resonance's, one coinciding with the ON-time interval and the other coinciding with the OFF-time interval resulting in all switches being turned ON and turned OFF at zero current. Primary side high voltage switches operate with zero-voltage switching for all load currents. Despite the two resonance's, the output voltage is controlled by use of the variable duty ratio, constant switching frequency PWM method. | 02-23-2012 |
20120092900 | CONTROLLER WITH PUNCTUATED SWITCHING CONTROL CIRCUIT - An example controller for use in a power supply includes a zero crossing detection (ZCD) circuit and a punctuated switching control circuit. The ZCD circuit is coupled to generate a ZCD signal in response to a zero-crossing of an ac input voltage of the power supply. The punctuated switching control circuit is coupled to the ZCD circuit to generate a switching signal to control a switch to regulate an output of the power supply. The punctuated switching control circuit generates the switching signal having an interval of switching and an interval of no switching in response to the ZCD signal, where the interval of switching has a beginning that is synchronized with the zero crossing of the ac input voltage and where the interval of no switching has a beginning that is synchronized with another zero crossing of the ac input voltage. | 04-19-2012 |
20120099344 | CONTROL DEVICE FOR A RESONANT CONVERTER - A control device controls a switching circuit of a resonant converter having an output direct current. The switching circuit includes at least a half-bridge of at least a first and a second transistor connected between an input voltage and a reference voltage. The half-bridge is adapted to generate a periodic square-wave voltage for driving the resonant circuit of said resonant circuit and the periodic square-wave voltage oscillates between a high voltage corresponding to the input voltage and a low voltage corresponding to the reference voltage. The control device comprises a generator adapted to generate a periodic square-wave signal for driving the half-bridge. The control device comprises a detector adapted to detect the phase-shift between the periodic square-wave signal generated by the generating means and the current flowing through the resonant circuit, and adapted to control the turning off of the half-bridge when the phase-shift exceeds a first phase-shift value. | 04-26-2012 |
20120212979 | FEEDBACK CIRCUIT FOR ZERO-VOLTAGE-SWITCHING CONVERTER - A feedback circuit for a zero-voltage-switching converter ( | 08-23-2012 |
20120250362 | SWITCHING REGULATOR CONTROL CIRCUIT - In a switching regulator control circuit according to aspects of the invention, a drain current is converted to a voltage Vis with a resistance. The voltage is delivered to a multiplication circuit. The multiplication circuit generates and outputs a voltage that is a product signal of the voltage and a voltage that is proportional to a duty factor. A comparator circuit compares the voltage with an error signal delivered to the other comparison input terminal of the comparator. When the voltage has reached the error voltage, the comparator delivers a turn-off instruction through an OR circuit to a terminal of a flip-flop. | 10-04-2012 |
20120281436 | ISOLATED DC-TO-DC VOLTAGE STEP-UP CONVERTER - An isolated DC-to-DC voltage step-up converter is provided with four switches, an input inductor, an isolation transformer, two resonant inductors and two resonant capacitors and operates with two distinct intervals: ON-time interval and an OFF-time interval. The two half-wave sinusoidal resonant capacitor charge and discharge intervals, one during the ON-time interval and the other during the OFF-time interval are chosen as to eliminate the losses due to energy stored in the leakage inductance of the isolation transformer and to operates with zero voltage switching of the primary side switches. It provides the output voltage regulation over the wide input voltage range with the same low voltage stresses of all four switching devices. The isolation transformer has full bi-directional flux capability and has DC bias. Despite the two independently controlled resonances, the output voltage is controlled by the duty ratio D control at constant switching frequency. | 11-08-2012 |
20120327692 | CONTROL DEVICE FOR A RESONANT CONVERTER - A control device for a resonant converter is described. The converter comprises a switching circuit adapted to drive a resonant circuit that includes at least one capacitor. The converter is adapted to convert an input signal into an output signal and the switching circuit includes at least a half bridge of first and second switches, the central point of said half bridge being connected to the resonant circuit. The control device comprises a controller adapted to generate at least a control signal of the switching circuit by comparing a signal representative of the energy of the resonant circuit with at least another signal. | 12-27-2012 |
20130121037 | Resonant Converting Circuit and Resonant Controller - A current detecting circuit detects a resonant current in a primary side of a resonant converting circuit to generate a current detecting signal. An output detecting circuit generates a feedback signal according to the output voltage. A resonant controller generates a clock signal and adjusts an operating frequency of the clock signal in response to the feedback signal for modulating the output voltage of the resonant circuit. The resonant controller includes a resonance deviation protection unit which detects the current detecting signal according to a phase of the clock signal to determine whether the resonant circuit enters a region of zero current switching or not. When the resonant circuit enters the region of zero current switching, the resonant controller executes a corresponding protection process in response to that the resonant controller operates in a starting mode or a normal operating mode. | 05-16-2013 |
20130182463 | VALLEY-DETECTION DEVICE FOR QUASI-RESONANCE SWITCHING AND METHOD USING THE SAME - A valley-detection device for quasi-resonance switching and a method using the same is disclosed, which uses first and second capacitors to connect with a comparator, and the comparator connects with an NMOSFET connecting to a transformer. When the NMOSFET is turned off, the energy stored in the transformer is discharged and a resonant signal across the source and the drain is generated, and a first constant current charges the first capacitor at a start time point of the resonant signal until a voltage of the resonant signal first reaches to a crossing voltage. Then, a second constant current charges the second capacitor when the voltage of the resonant signal equals to the crossing voltage while the voltage of the resonant signal varies from high to low. Finally, the comparator turns on the NMOSFET when a voltage of the second capacitor equals to a voltage of the first capacitor. | 07-18-2013 |
20130301308 | SWITCHING POWER SUPPLY DEVICE - In a switching power supply device with reduced size and increased power conversion efficiency, a first resonant circuit including a series resonant inductor and a series resonant capacitor, and a second resonant circuit including a series resonant inductor and a series resonant capacitor, are caused to resonate with each other to cause sympathetic vibration of each resonant circuit, such that transmission is performed by utilizing both magnetic field coupling and electric field coupling between a primary winding and a secondary winding. Operation at a switching frequency higher than a specific resonant frequency of an overall multi-resonant circuit allows a ZVS operation to be performed, enabling a significant reduction in switching loss and high-efficiency operation. | 11-14-2013 |
20130308347 | RESONANT SWITCHING POWER SUPPLY DEVICE - A winding voltage arising in a first winding on the primary side of a transformer is detected in a winding voltage detector unit formed of a second winding, and current flowing through a resonant circuit is detected in a resonant current detector unit formed of an auxiliary capacitor and a resistor. The timing at which the polarity of the detected winding voltage is inverted is detected in a control and drive unit, and the time at which the polarity of the resonant current, whose phase is delayed with respect to that of the winding voltage, will be inverted is determined in advance. In the event that there is a switch in an on-state when the timing immediately before the inversion of the polarity of the resonant current is detected from the output of the resonant current detector unit, the control and drive unit forcibly turns off the switch. | 11-21-2013 |
20130329465 | QUASI-RESONANT DEVICE AND SYSTEM AND METHOD FOR QUASI-RESONANT CONTROL OF SWITCHING POWER - A quasi-resonant device for a switching power, a quasi-resonant system for a switching power, and a method for a quasi-resonant control of a switching power are provided. The quasi-resonant device includes: a degaussing time sampling module, configured to sample a degaussing time T | 12-12-2013 |
20140043865 | SYNCHRONOUS RECTIFIER CONTROL TECHNIQUES FOR A RESONANT CONVERTER - A resonant converter system includes a first stage having inverter circuitry and resonant tank circuitry configured to generate an AC signal from a DC input signal, a transformer configured to transform the AC signal, and a second stage. The second stage features synchronous rectifier (SR) circuitry including a plurality of SR switches each having a body diode and SR control circuitry. SR control circuitry is configured to generate gate control signals to control the conduction state of the SR switches so that the body diode conduction time is minimized and a negative current across the SR switches is reduced or eliminated. The method includes controlling the conduction state of SR switches to conduct as the body diode associated with the switch begins to conduct and controlling the SR switch to turn off as the current through the switch approaches a zero crossing. | 02-13-2014 |
20140133190 | ISOLATED SWITCH-MODE DC/DC CONVERTER WITH SINE WAVE TRANSFORMER VOLTAGES - A converter includes a transformer including a primary winding and a secondary winding, a primary-side circuit connected to first and second input terminals and to the primary winding and including a switching circuit connected to the primary winding and a parallel resonant tank circuit including the primary winding and a resonant capacitor connected in parallel with the primary winding, a secondary-side circuit connected to the secondary winding and to first and second output terminals and including a rectifier circuit connected to the secondary winding, and an inductor including a primary inductor winding connected to the first input terminal and the primary winding and a secondary inductor winding connected to the secondary winding and the first output terminal. | 05-15-2014 |
20140247627 | CONVERTER AND METHOD - In accordance with an embodiment, a method for controlling a circuit includes controlling pulse width modulation on a primary side of a quasi-resonant controller to achieve continuous current mode operation from a synchronous rectification controller on a secondary side. | 09-04-2014 |
20140268908 | CONVERTER TOPOLOGIES - Inverter topologies for converting an input direct current (DC) waveform from a DC source to an output alternating current (AC) waveform are disclosed. In some disclosed embodiments, an inverter may include a full bridge LLC resonant converter, a first boost converter, and a second boost converter. In such embodiments, the first and second boost converters operate in an interleaved manner. In other disclosed embodiments, the inverter may include a half-bridge inverter circuit, a resonant circuit, a capacitor divider circuit, and a transformer. | 09-18-2014 |
20140286056 | SWITCH CONTROL CIRCUIT, POWER SUPPLY DEVICE COMPRISING THE SAME AND DRIVING METHOD OF THE POWER SUPPLY DEVICE - The invention relates to a switch control circuit, a power supply including the same, and a method for driving the power supply. The power supply includes: a first switch; a second switch coupled in series to the first switch; a transistor coupled to a node where the first switch and the second switch are coupled; a resonance capacitor coupled between the transformer and a primary side ground and to which a resonance current flows; a sense circuit generating a first sense voltage that depends on the resonance current when the resonance current is a positive current; and a switch control circuit detecting a zero voltage switching failure by sensing the resonance current using the first sense voltage at a turn-off time of the first switch for every switching cycle of the first and second switches. | 09-25-2014 |
20140369083 | RESONANT CONVERTER, POWER SUPPLY AND POWER CONTROLLING METHOD THEREOF - A resonant converter, a power supply and a power controlling method thereof are provided. The power supply includes a resonant converter which includes a square wave generator configured to alternately turn on and off first and second switches according to a frequency to generate a square wave, a resonant wave generator configured to generate a resonant wave corresponding to the square wave and a rectifier configured to output a voltage corresponding to the resonant wave; and a controller configured to control a frequency modulation of the resonant converter, wherein the controller includes a variable switching circuit configured to increase the frequency of the resonant converter in response to the resonant converter entering a capacitive mode. | 12-18-2014 |
20140369084 | ELECTRICAL CIRCUIT FOR DELIVERING POWER TO CONSUMER ELECTRONIC DEVICES - An electrical circuit for providing electrical power for use in powering electronic devices is described herein. The electrical circuit includes a power converter circuit that is electrically coupled to an electrical power source for receiving alternating current (AC) input power from the electrical source and delivering direct current (DC) output power to an electronic device. The power converter circuit includes a transformer and a switching device coupled to a primary side of the transformer for delivering power from the electrical power source to a primary side of the transformer. A controller is coupled to a voltage sensor and the switching device for receiving the sensed voltage level from the voltage sensor and transmitting a control signal to the switching device to adjust the voltage level of power being delivered to the electronic device. | 12-18-2014 |
20150009718 | METHOD AND APPARATUS FOR EXTENDING ZERO-VOLTAGE SWITCHING RANGE IN A DC TO DC CONVERTER - Method and apparatus for extending a zero voltage switching (ZVS) range during power conversion. In one embodiment, the apparatus comprises a DC/DC converter, operated in a quasi-resonant mode, comprising a transformer; a primary switch, coupled to a primary winding of the transformer, for controlling current flow through the primary winding; and a component coupled to the transformer, wherein the component has a capacitance that varies with voltage across the component, and wherein during a downswing in voltage across the primary switch the component is passively tuned by a change in the voltage across the component that changes the capacitance of the component, and wherein the passive tuning of the component causes a resonant frequency of the DC/DC converter to change, and wherein the change in the resonant frequency causes the downswing to accelerate. | 01-08-2015 |
20150043249 | CONTROL DEVICE FOR RECTIFIERS OF SWITCHING CONVERTERS - A control device controls a rectifier of a switching converter that is supplied with an input voltage and provides an output current. The rectifier is configured to rectify the output current of the converter and has at least one transistor. The control device, when the at least one transistor is turned off, provides a slow discharge path to ground in a normal operation condition and provides a fast discharge path to ground for discharging the control terminal of the at least one transistor in response to detecting a zero cross event of the current flowing through said at least one transistor. | 02-12-2015 |
20150049522 | CONTROL DEVICE FOR RECTIFIERS OF SWITCHING CONVERTERS - A control device detects zero crossings of a current through a rectifier transistor during plural cycles; generates a turn-on signal of the transistor and inserts a turn-on delay equal to a fixed first quantity from the start time of for each cycle. The control device starts counting consecutive cycles after inserting the turn-on delay; detects whether a zero crossing of the current through the transistor after turning on said transistor has occurred; if no zero crossing is detected before counting a number N of consecutive cycles, decreases the turn-on delay by a fixed second quantity for the next cycle; if a zero crossing is detected, maintains turned on the transistor; if the turn-on delay is smaller than first quantity, increases the turn-on delay o for the next switching cycle; and if the turn-on delay is equal to the first quantity, maintains the turn-on delay for the next switching cycle. | 02-19-2015 |
20150055377 | Techniques to Reduce Audible Noise in a Power Supply Transformer - This disclosure relates to a switching power supply with regulated voltage suppression to reduce transformer audio noise. The switching power supply is operable to be fed a zero crossing voltage and to generate an output voltage. The output voltage may have a voltage level set using a modulated gate signal. A circuit is provided to reduce audio noise in a switching power supply by setting a ringing suppression time of the modulated gate signal to a first time period when the zero crossing voltage is below a predetermined voltage threshold and to a second time when the zero crossing voltage is above the predetermined threshold voltage. | 02-26-2015 |
20150070943 | HIGH EFFICIENCY ZERO-VOLTAGE SWITCHING (ZVS) ASSISTANCE CIRCUIT FOR POWER CONVERTER - A system includes a power converter configured to convert input power into output power. The power converter includes first and second converter bridges, where each converter bridge includes multiple transistors. The system also includes a zero-voltage switching (ZVS) assistance circuit having first and second inverse controlled rectifiers (ICRs). Each of the first and second ICRs is configured to provide current to the transistors in the first and second converter bridges. The system further includes a controller configured to control operation of the first and second converter bridges and the ZVS assistance circuit. The controller could include a phase-shift modulation (PSM) controller configured to control the converter bridges and a pulse width modulation (PWM) controller configured to control the ZVS assistance circuit. The PWM controller can be configured to apply pre-shaped voltages to transistors in regulators of the ICRs to enable substantially zero-loss turn-off commutation of the transistors in the regulators. | 03-12-2015 |
20150109830 | RESONANT POWER CONVERSION APPARATUS AND CONTROLLING METHOD THEREOF - A resonant power conversion apparatus and a controlling method of the resonant power conversion apparatus are provided. The resonant power conversion apparatus includes a switch-based resonant converter and a controller. The switch-based resonant converter is configured to supply power to a load. The controller is coupled to the switch-based resonant converter and the load and configured to control switching of the switch-based resonant converter to regulate power conversion of the switch-based resonant converter. The controller has a voltage control loop and a current control loop. The controller detects a driving state of the load and enables one of the voltage control loop and the current control loop according to the detection result to adjust a switching frequency of the switch-based resonant converter. | 04-23-2015 |
20150131337 | Resonant Isolated Active PFC Rectifier - A method of driving an isolated converter includes opening a first bi-directional switch on an input side of a transformer, accepting current into a resonant capacitor connected across the first bi-directional switch to reduce voltage across the first bi-directional switch in response to said opening the first bi-directional switch, reversing current out of the resonant capacitor, and closing the first bi-directional switch as voltage across the first bi-directional switch is approximately zero volts. | 05-14-2015 |
20150295497 | Systems and Methods for a Variable Frequency Multiplier Power Converter - A power converter for converting DC power to DC power includes an inverter stage having two or more switched inverters configured to receive DC power from a source and produce a switched AC output power signal. A transformation stage is coupled to receive the switched output power signal from the inverter stage, shape the output power signal, and produce a shaped power signal. A rectifier stage having two or more switched inverters coupled to receive the shaped power signal and convert the shaped power signal to a DC output power signal is included. A controller circuit is coupled to operate the power converter in a variable frequency multiplier mode where at least one of the switched inverters is switched at a frequency or duty cycle that results in an output signal having a frequency that is a harmonic of the fundamental frequency being generated by the power converter. | 10-15-2015 |
20150303818 | FLYBACK ACTIVE CLAMPING POWER CONVERTER - A flyback active clamping power converter is disclosed. The flyback active clamping power converter comprises an input inductor, a down-bridge switch, an up-bridge switch, a first energy-storing capacitor, a clamping capacitor, a resonant inductor, a magnetizing inductor, a transformer, an output diode and an output capacitor. When a resonant frequency generated by the resonant inductor and the clamping capacitor in the flyback active clamping power converter is substantially equal to a switching frequency, the output diode is able to perform a zero current switching in the whole load range. | 10-22-2015 |
20150333634 | DC-TO-DC CONVERTER - A DC to DC converter includes: first and second switching elements connected at a first connection point between a first input/output terminal and a first ground terminal; third and fourth switching elements connected at a second connection point between the first input/output terminal and the first ground terminal; a resonant capacitor and a resonant inductor connected in series between the first and second connection points; fifth and sixth switching elements connected at a third connection point between a second input/output terminal and a second ground terminal; seventh and eighth switching elements connected at a fourth connection point between the second input/output terminal and the second ground terminal; a transformer; and a control circuit. The control circuit is operable to adjust the pulse waveforms for switching the fifth to eighth switching elements when voltage at the second input/output terminal is stepped down and output from the first input/output terminal. | 11-19-2015 |
20150349649 | ZERO VOLTAGE SWITCHING OPERATION OF A MINIMUM CURRENT TRAJECTORY FOR A DC-TO-DC CONVERTER - An apparatus for zero voltage switching is disclosed. A system and method also perform the functions of the apparatus. The apparatus includes an MCT region module that defines a minimum current trajectory (“MCT”) for operation between a maximum positive power output to a maximum negative power output of a bidirectional DC-to-DC converter. The converter includes a dual active bridge series resonant converter. The MCT defines a boundary between a zero voltage switching (“ZVS”) region and a hard switching region. The apparatus includes an offset module that defines an offset to the MCT, the offset in the ZVS region, and an MCT control module that adjust switching of switches of the converter to maintain operation of the converter in the ZVS region between the maximum positive power output to a maximum negative power output along a trajectory defined by the MCT and the offset. | 12-03-2015 |
20150381060 | QUASI-RESONANT HALF-BRIDGE CONVERTER AND CONTROL METHOD THEREOF - A quasi-resonant half-bridge converter includes a switch unit including first and second switches that are coupled in series, a capacitor unit coupled to the switch unit in parallel, a rectifier unit, an output capacitor, and a transformer coupled to the aforesaid components. The first and second switches are respectively controlled using first and second control signals that have a constant frequency. Duty cycles of the first and second control signals may be adjusted based upon a DC output voltage across the output capacitor for promoting conversion efficiency of the converter when operating at light load. | 12-31-2015 |
20160087543 | RESONANT CONVERTER, CONTROL CIRCUIT AND ASSOCIATED CONTROL METHOD WITH ADAPTIVE DEAD-TIME ADJUSTMENT - A resonant converter has a switching circuit having a first switch and a second switch, a control circuit and a resonant circuit. The control circuit has a slope sensing circuit providing a slope sense signal based on a voltage variation at the common node of the first switch and the second switch, a slope judge circuit providing a slope judge signal, and a turn-ON control circuit providing a first reset signal to adjust a first dead-time period from turning OFF the first switch to turning ON the second switch based on the slope judge signal, the slope signal, and a current flowing through the resonant tank, and providing a second reset signal to adjust a second dead-time period from turning OFF the second switch to turning ON the first switch based on the slope judge signal, the slope signal, and the current flowing through the resonant tank. | 03-24-2016 |
20160094137 | Soft Transition on all Switching Elements Two Transistors Forward Converter - A method is shown to improve any forward topology operation to achieve efficient resonant transitions by actively shorting the magnetizing inductance and release the short at another time thus producing lower switching losses independent of frequency. In another embodiment of this invention the current from the output inductor is allowed to go negative before the freewheeling synchronous rectifier is turned off, pushing the current back into the primary to create a soft transition across the switching elements before they are turned on. In another embodiment of the invention a current source is used to inject a negative current through the freewheeling synchronous rectifier before is turned off with the purpose of transferring the current into the primary to discharge the parasitic capacitances of the primary switchers before are turned on. An optimized control method can be utilized to tailor the frequency to create the necessary conditions requested by the embodiments of the invention. | 03-31-2016 |
20160141960 | Zero Voltage Switching Detection Apparatus and Method - A converter comprises a switch network coupled to a power source, wherein the switch network comprises a plurality of power switches, a magnetic device coupled to the switch network, a detector coupled to the magnetic device through a magnetic coupling and a control circuit configured to receive a zero voltage switching signal from the detector and adjust gate drive signals of the power switches based upon the zero voltage switching signal. | 05-19-2016 |
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