Abstract: A power adaptor is provided. The power adaptor includes a connector, a rectifier, a filter, a regulator and a switching unit coupled between the rectifier and the filter. The connector receives an alternating current (AC) power. The rectifier provides a direct current (DC) power according to the AC power. The filter filters the DC power to generate a filtered signal. The regulator provides an output voltage according to the filtered signal. A switching state of the switching unit corresponds to the DC power.

Abstract: A power distribution system and method includes a controller that is configured to control a switching power converter. In at least one embodiment, the controller includes a compensation current control circuit to control a compensation current that reduces and, in at least one embodiment, approximately eliminates variations in current drawn by the controller during a particular operational time period. In at least one embodiment, the power distribution system is a lamp that includes the controller, a switching power converter, and one or more light sources, such as light emitting diodes.

Abstract: Forward boost power converters, and related methods, are disclosed. In a switching mode power converter coupled between a first terminal pair and a second terminal pair, a first inductance is coupled to a first switch in a first circuit path across the first terminal pair. A capacitance is coupled to a second inductance in a second circuit path, and to the first inductance in a third circuit path. During their respective conduction periods, the first switch couples the first inductance across the first terminal pair, a second switch completes a circuit between the second terminal pair and one of: the second circuit path or the third circuit path, and a third switch completes the other of: the second circuit path and the third circuit path. Energy transfer involves both substantially linearly varying currents and substantially half sinusoidal current pulses.

Abstract: A bi-directional DC/DC converter comprises bridge circuits connected to DC voltage sources, an isolation transformer, an LC resonance circuit, and detection circuits for detecting voltages and currents of the DC voltage sources. A control circuit in the power flow from a first DC voltage source to a second DC voltage source changes over between fixed frequency control and frequency modulation control according to the magnitude of a control variable, and a control circuit in the power flow from a second DC voltage source to the first DC voltage source changes over between fixed frequency control and frequency modulation control according to the magnitude of another control variable. Thus, the bi-directional DC/DC converter can be applied to devices with a wide range of input and output voltages.

Abstract: An approach is provided for limiting or eliminating residual energy in a resonant network before restarting a resonant converter including the resonant network. An energy resetting module is configured to the resonant converter for limiting a peak current occurring in a switching circuit of the resonant converter by resetting energy remaining in a resonant circuit of the resonant converter after the resonant converter is turned off.

Abstract: The present invention relates to a power supply with output protection and a control method of the power supply. The invention mainly provides a pre-protection value lower than a default over-current protection value. When a present output current of the power supply is higher than or equal to the pre-protection value and is lower than the over-current protection value, the method firstly determines whether the power supply has abnormal conditions. When the power supply has abnormal conditions, the method can automatically provide or stop providing a working voltage to a load. When the present output current is further higher than or equal to the over-current protection value, the method takes an over-current protection action. By multi-level monitoring of the current values, the invention properly provides an over-current protection.

Abstract: A temperature control system for a battery in an energy storage system is disclosed. In one aspect, the temperature control system includes a circuit configured to determine that the temperature of the battery has been maintained below a normal operation temperature for a predetermined duration. The circuit is further configured to alternatingly repeat charging and discharging operations using a winding in a primary side of an inverter to generate reactive current to flow in opposite directions through the battery until the temperature of the battery is restored to the normal operation temperature.

Abstract: Aspects of the disclosure provide a method. The method includes receiving an input voltage rectified from an alternating current (AC) power supply, detecting a time duration that the input voltage is between a first threshold voltage and a second threshold voltage, determining a line voltage of the AC power supply based on the time duration, and regulating a time for turning on a switch to transfer energy via a transformer based on the detected line voltage.

Abstract: The present application provides a mixed control method for a resonant converter, a resonant converter system and a mixed controller. When the resonant converter operates in a case where a voltage gain is less than a predetermined value, the method includes: setting a mixed control start frequency, a mixed control stop frequency and a slope of a phase-shifting angle; detecting an operating frequency of the converter; calculating a time delay of phase shifting according to the slope, the mixed control start frequency, the mixed control stop frequency and a resonant frequency of the resonant converter; and according to the time delay, the mixed control start and stop frequencies, generating a control signal to adjust the operating frequency and the phase-shifting angle of the resonant converter. The present application can realize a relatively low voltage gain and a small circuit loss, thereby the circuit efficiency may be improved.

Abstract: A capacitor charger system has a resonant power converter to connect to a capacitor via a rectifier. The resonant power converter has a switch-based bridge network, an internal transformer, a resonant circuit, and an amplitude stabilization circuit. The switch-based bridge network comprises at least one pair of switches. The resonant circuit includes a series-resonant branch with capacitive and inductive components, and the resonant circuit is connected in the circuit path to a midpoint between a pair of switches of the switch-based bridge network. The amplitude stabilization circuit provides stabilization of the resonant amplitude of the resonant circuit, and the amplitude stabilization circuit includes one-way conducting circuitry connected between an unrestricted node defined by a junction and a connection point of the resonant power converter having a predefined voltage level at operation. The resonant power converter connects to the output rectifier via the secondary winding of the internal transformer.

Abstract: An electronic resonant circuit of very high efficiency which is suitable for driving loads with a known and controlled current. The resonant circuit has input terminals and output terminals with a first reactance Xs, in series with an input terminal, a second reactance XL, in series with an output terminal, and a reactance Xp, connected such that there is a series connection path between the first input terminal through Xs and Xp to the second input terminal and such that there is also a second series connection path between the first output terminal through XL and Xp to the second output terminal the input terminals being driven from a high frequency inverter, the output terminals being connected to a load, the value of the reactances Xs, XL and Xp being chosen such that at least one frequency, the reactances of Xs, XL and Xp are approximately similar in magnitude.

Abstract: A series resonant power converter includes a power stage comprising a switching circuit operating at least a resonant frequency. To achieve soft switching and provide current at a voltage through an inductive element. The power converter can also include a control circuit for controlling a phase angle of the current, for controlling a duty cycle of the switching circuit.

Abstract: This disclosure provides control techniques for a resonant converter. In one control technique, for switching speeds that are below the resonant frequency of the primary stage of the converter, the switches of the synchronous rectifier (SR) portion (SR switches) of the resonant converter are controlled based on a rising edge of the corresponding primary side switch and the turn off time of a corresponding SR switch. In general, for below resonance operation, each corresponding SR switch will be turned off prior to the falling edge of each corresponding primary side switch, while each corresponding SR switch will be turned on at the rising edge of the each corresponding primary side switch. The conduction time of respective SR switches is generally constant for below resonance operation.

Abstract: 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.

Abstract: A resonant power conversion apparatus including a transformer-based resonant converter and first and second switch control units is provided. The transformer-based resonant converter includes a primary switch circuit and a secondary output circuit configured to provide an output voltage to a load. The first switch control unit is configured to control an ON/OFF operation of the primary switch circuit in response to a status of the load. The second switch control unit is configured to determine whether to activate or inactivate the first switch control unit. When the status of the load is the light-loading or the no-loading, the first switch control unit intermittently controls the ON/OFF operation of the primary switch circuit, and meanwhile, the first switch control unit is inactivated during the primary switch circuit is disabled, so as to substantially reduce the light-loading or no-loading loss of the resonant power conversion apparatus.

Abstract: A method comprises providing a resonant converter, wherein the resonant converter comprises an input switch network coupled to a power source, wherein the input switch network comprises a plurality of power switches, a resonant tank coupled to the plurality of power switches, a transformer coupled to the resonant tank and an output stage coupled to the transformer, wherein the output stage comprises a synchronous rectifier formed by a first switch and a second switch, detecting a drain voltage of the first switch, comparing the drain voltage with a predetermined voltage threshold, wherein the drain voltage is coupled to a negative input of a comparator and the predetermined voltage threshold is coupled to a positive input of the comparator, generating a logic state based upon an output of the comparator and adjusting, by a control circuit, a switching frequency of the resonant converter based upon the logic state.

Abstract: A high voltage power source device includes piezoelectric transformers, each of the piezoelectric transformers being formed with a primary electrode and a secondary electrode on piezoelectric ceramics, receiving a primary voltage at the primary electrode, and generating a second voltage from the secondary electrode, switching elements, each of the switching elements driving a respective one of the piezoelectric transformers, and primary voltage supply devices, each of the primary voltage supply devices supplying the primary voltage to the primary electrode of the respective one of the piezoelectric transformers by driving the respective one of the switching elements when the secondary voltage is generated from the respective one of the second electrodes, wherein the respective one of the primary voltage supply devices supplies the primary voltage to the respective one of the primary electrodes by driving the respective one of the switching elements at the same frequency.

Abstract: A power factor correction (PFC) power converter is disclosed that converts AC input power to DC output power. A single stage of the PFC power converter performs both the DC-DC power conversion and the power factor correction for the power converter. The disclosed PFC power converters are efficient in energy conversion and have a power factor of 0.9-1.0. Further, the disclosed PFC power converters can be implemented in both low and high power applications above 75W.

Abstract: 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.

Abstract: A switching power supply with a resonant converter has an AC to DC converter and a DC to DC converter. The AC to DC converter converts an inputted AC power into a DC power. The DC to DC converter has a resonant converter determining a current operating state according to waveforms of a transformer voltage and a driving signal actually measured and further controlling a switching frequency of the resonant converter to approach or to be equal to a resonant frequency for operational efficiency enhancement. Accordingly, the failure to accurately calculate a resonant frequency beforehand can be solved and the issue of accurately keeping the switching frequency consistent with the resonant frequency can be tackled.

Abstract: A parallel resonant converter including a control circuit and at least two resonant conversion circuits connected in parallel between an input bus and an output bus is provided by the invention. The control circuit is configured to provide a switching frequency signal to the at least two resonant conversion circuits. Moreover, the control circuit is further configured to control the voltage of the output bus to linearly vary along with the switching frequency signal in a rated range by using a linear current-balancing curve (gain-frequency), and thus achieving the purpose of current-balancing for the at least two resonant conversion circuits. The invention is capable of controlling the output voltage of the parallel resonant converter, so as to reduce the ripple on the output voltage of the power supply system.

Abstract: A circuit includes a conduction detector configured to monitor conduction of a body diode of a synchronous rectifier switch relative to a predetermined threshold and to generate a detector output that indicates conduction or non-conduction of the body diode. A window analyzer is configured to generate a timing signal to indicate if the synchronous rectifier switch is turned off prematurely or turned off late relative to an on-time turn off based on the detector output from the conduction detector. A controller is configured to adjust the timing of the synchronous rectifier switch based on whether the timing signal indicates that the synchronous rectifier switch is turned off prematurely or turned off late relative to the on-time turn off.

Abstract: A controller for use with a power converter and method of operating the same. In one embodiment, the controller includes a gate drive terminal configured to provide a gate drive signal to enable conductivity of a power switch during a first portion of a switching interval and to disable conductivity of the power switch during a second portion of the switching interval. The controller also includes a current sense terminal configured to receive a power switch signal indicative of a current in the power switch during the first portion of the switching interval, and receive a control signal to operate the power converter or provide a status signal indicative of an operating condition of the power converter during the second portion of the switching interval.

Abstract: The present invention includes: a series circuit formed of a reactor Lr, a primary winding P of a transformer T, and a capacitor C2; a full-wave rectifier/smoothing circuit D1, D2, C3 configured to perform full-wave rectification and smoothing on a voltage generated in a secondary winding S of the transformer thereby to extract a DC voltage; a control circuit FF1 configured to set a first ON time of the first switch element Q1 and a second ON time of the second switch element Q2 to the same predetermined time thereby to alternately turn on and off the first switch element and the second switch element; and a first ON time controller I1, I6, C7 configured to set one of the first ON time and the second ON time, shorter than the predetermined time, under light-load conditions, based on the DC voltage detected by a detector 11.

Abstract: A single stage PFC LLC power converter is consist of two transformer, one forward transformer, one main transformer. The first winding of the forward transformer is connected with a capacitor in series then paralleled with another capacitor and this circuit is connected with the primary winding of the main transformer in series as primary load circuit in LLC power converter, the energy through the main transformer is transferred to the secondary circuit and the energy through the first winding of the forward transformer is transferred to the second winding of the forward transformer to correct the input current waveform.

Abstract: A motor driving device comprises: an AC/DC converter that converts alternating current power into direct current power; a motor driving unit that operates based on the direct current power supplied from the AC/DC converter and outputs a driving signal to a motor; and a start-up auxiliary circuit that is arranged on a path connecting the AC/DC converter and the motor driving unit, wherein the start-up auxiliary circuit: delays an output of the driving signal for a first predetermined time period after the supply of the alternating current power from the alternating current power supply to the AC/DC converter starts; and gradually increases a driving voltage so that current flowing in a driving coil of the motor is limited to a predetermined value or smaller for a second predetermined time period after the output of the driving signal from the motor driving unit starts.

Abstract: A switching power supply includes a series resonant circuit that includes a resonant inductor and a resonant capacitor connected in series with a primary winding of a converter transformer. By controlling turning on and off of first and second switching elements in a complementary manner, current is supplied to the series resonant circuit. A third switching element connected on the secondary side of the converter transformer is synchronized with the first switching element, and a fourth switching element is synchronized with the second switching element. If a switching frequency is less than a resonant frequency, turning on of the third and fourth switching elements is synchronized with turning on of the first and second switching elements, and turning off of the third and fourth switching elements is controlled, without being synchronized with turning off of the first and second switching elements, after half a resonant period has elapsed.

Abstract: A current resonance power supply includes a current detecting unit detecting a current flowing through a primary side of a transformer and a current compensating unit compensating the current detected by the current detecting unit in accordance with a variation in voltage input into the primary side of the transformer. The current resonance power supply detects overcurrent on the basis of an output from the current compensating unit.

Abstract: A DC-DC converter device and method for controlling the DC-DC converter device includes controlling gate drivers connected to the respective gate of first and second resonant circuit switches of a resonant circuit, controlling gate drivers connected to the respective gate of first and second rectifier switches of a synchronous rectifier, and detecting whether a shutdown criteria is fulfilled or not. If the shutdown criteria is fulfilled, the method is further includes the step of sending a shutdown signal to a shutdown device.

Abstract: The high voltage inverter device receives, as an input voltage, a DC voltage or a voltage within Safety Extra Low Voltage composed of a DC component with a pulsating flow superposed thereon. The input voltage is switched by a switching element to pass an exciting current to excitation windings on a primary side of a plurality of separate transformers having same characteristics to simultaneously excite the excitation windings. Output windings of the plurality of transformers are connected in parallel or in series with one another, and time axes of waveforms of output voltages of the output windings are synchronized. Thereby, a high-power high voltage is outputted continuously, stably, and safely from both ends of the output windings connected in parallel or in series.

Abstract: An open loop power conversion apparatus is applied to a load apparatus and an input power. The open loop power conversion apparatus outputs a predetermined voltage to the load apparatus. The open loop power conversion apparatus includes a resonant inductor, a magnetic inductor, a resonant capacitor, and a transformer. The resonant inductor has a non-uniform air gap. An inductance of the resonant inductor is decreasing when a current outputted from the open loop power conversion apparatus to the load apparatus is increasing. An output voltage gain of the open loop power conversion apparatus is increasing, so that the predetermined voltage is increasing.

Abstract: The disclosure provides a power controller and related control method for a switch mode power supply operating in a quasi-resonant mode. The switched mode power supply has a power switch and an auxiliary winding. The power controller has a feedback pin connected to the auxiliary winding. A clamp circuit is connected to the feedback pin and configured for clamping a voltage at the feedback pin by providing a clamp current. A peak hold circuit is connected to the clamp circuit for generating a peak record substantially corresponding to a peak value of the clamp current. A valley detector is configured for providing an entry signal indicating a start of a voltage valley. A delay circuit provides a trigger signal a delay time after the entry signal is provided. The delay time varies in response to the peak record, and the trigger signal is capable of turning on the power switch.

Abstract: An efficiency monitor for monitoring the efficiency of power transmission by an inductive power outlet. The efficiency monitor includes an input power monitor, for measuring the input power delivered to the primary coil, and an output power monitor, for measuring the output power received by the secondary coil. The input and output powers are used by a processor to determine an index of power-loss. A circuit breaker may be used to disconnect the inductive power outlet in case of excessive power loss.

Abstract: A DC power supply including a resonant circuit on a secondary side of a transformer suppresses a surge voltage during power recovery of diodes constituting a rectifier circuit, correctly estimates a load current from a secondary current of the transformer, and adjusts supplied power when a load is light. The DC power supply includes a DC voltage source, a converter, a transformer, a rectifier circuit, a resonant circuit composed of a resonant switch and a resonant capacitor, a filter reactor, a filter capacitor, a snubber diode, a snubber capacitor, a load, first and second voltage sensors, a current sensor, and a controller for controlling gate pulses of semiconductor devices constituting a converter and the resonant switch and a signal for adjusting operation timings of A/D converters converting the signals of these sensors.

Abstract: A resonant converter and its controlling method are provided. The resonant converter includes a bridge switching circuit receiving a DC input voltage through its power terminal, a resonant and transforming circuit, a rectifying and filtering circuit, and an over-current protecting circuit. The resonant and transforming circuit has at least one resonant capacitor charged/discharged in response to the switching of the bridge switching circuit. The rectifying and filtering circuit rectifies and filters outputs of the resonant and transforming circuit, and generates a driving voltage accordingly. The over-current protecting circuit is coupled to the power terminal and crosses over the resonant capacitor to form a clamp path. The over-current protecting circuit detects a current flowing through the resonant and transforming circuit or a load and determines whether to conduct/cut off the clamp path according to the detection result to limit a cross voltage of the resonant capacitor within a first voltage range.

Abstract: A control device for a rectifier of a switching converter that includes a rectifier with at least one MOS transistor and a control device that is configured to generate a turn on and off signal for the at least one transistor. The control device also includes a measuring circuit to measure the conduction time of the body diode of the at least one transistor during each converter switching half-cycle. The control device is configured to, cycle by cycle: verify if the drain-source voltage of the at least one transistor is greater or less than a voltage threshold, and if the drain-source voltage is greater than the voltage threshold to turn off the at least one transistor, measure the conduction time of the body diode and increase the voltage threshold by a quantity in the next switching cycle.

Abstract: An electrical power converter includes a circuit with a single switching transistor that is electrically connected to a direct current power source, a first inductor-capacitor (LC) circuit electrically connected to the single switching transistor, a second LC circuit electrically connected to the first LC circuit and configured to provide an output signal to a load. A controller is operatively connected to the single switching transistor. The controller identifies an error between the output signal of the circuit and a reference signal and adjusts a duty cycle of a pulse width modulation (PWM) switching signal to switch the single switching transistor at a predetermined frequency with the adjusted duty cycle to reduce the identified error.

Abstract: A power supplying device is electrically connected to an alternating current (AC) power supplier and an electronic system. The power supplying device includes a rectifier, a power converter, a controller, a power manager, and a switch component. The power converter is electrically connected to the rectifier and includes a first electric power outputting terminal and a standby electric power outputting terminal. The standby electric power outputting terminal is electrically connected to the electronic system. The controller is electrically connected to the power converter. The power manager is electrically connected to the controller and the electronic system. The switch component is electrically connected to the first electric power outputting terminal, the power manager, and the electronic system. The switch component conducts or cuts-off an electric power outputted form the first electric power outputting terminal and transmitting to the electronic system according to controls of the power manager.

Abstract: Provided is an inverter of a renewable energy storage system, which has an input port and an output port electrically insulated, and is compact and low-priced, while having a simplified circuit. The inverter includes a DC-DC converting unit connected to the DC link, and an inverting unit connected between the DC-DC converting unit and the power system, wherein the DC-DC converting unit is an unregulated DC-DC bus converter.

Abstract: A control section for a current resonant converter section controls a DC output voltage of a current resonant converter section to settle to a target voltage by varying a resonant period between predetermined two resonant periods based on an error signal between the DC output voltage and the target voltage. A gain converter is provided in a preceding stage of a frequency generator for generating a square waveform signal with a duty ratio of 50% and the gain converter has a setting of a nonlinear gain characteristic that cancels nonlinearity in the input-output characteristics of the current resonant converter section. The nonlinear gain characteristic can be a characteristic of continuous gain conversion or discrete gain conversion.

Abstract: A common-core power factor correction resonant converter includes an energy-transforming circuit. The energy-transforming circuit receives an input line voltage and generates an output power. The energy-transforming circuit includes a coupling inductor and a charge-storage capacitor. The coupling inductor and the charge-storage capacitor are charged by the input line voltage in response to a control signal, so as to generate a charge-storage capacitor voltage. When the charge-storage capacitor voltage is charged to a preset voltage level, the coupling inductor and the charge-storage capacitor are discharged according to the control signal. Then, the energy in the coupling inductor and the charge-storage capacitor is transformed to the output load and provide the output voltage or current regulation.

Abstract: The power supply apparatus includes a transformer; a switching unit that causes two switching elements connected in series to drive the primary winding of the transformer; a detection unit that detects current flowing on the primary side of the transformer; a correction unit that corrects a detection result of the detection unit according to an input voltage input into the transformer; and a nonlinear correction unit that corrects the detection result such that correction by the correction unit is nonlinear to the input voltage.

Abstract: An electric power conversion device includes a primary circuit having a resonance inductor, a switch unit, and a primary winding of a transformer. A secondary circuit supplies an electric power to primary winding of transformer to supply an energy generated on secondary winding to a load. Switch unit includes first and second diodes connected in parallel to each other, first and second switching elements and a resonance capacitor. Furthermore, secondary circuit includes an output inductor between secondary windings and load. This structure achieves reductions of a loss, a size, and a cost and makes possible to suppress a destruction possibility of semiconductor elements and a worsening of a power factor.

Abstract: A switching power supply of certain aspects of the invention includes a minimum dead time generating circuit that generates a minimum dead time from an OFF timing of an ON pulse detected from the voltage across an auxiliary winding of the transformer by a differentiating circuit. An ON width-determining means of a voltage control oscillator is started, after this minimum dead time, into operation to determine the ON width of the semiconductor switch.

Abstract: A method of controlling a switching converter and a related controller suitable for the switching converter allow to implement a burst-mode functioning without generating acoustic noise and with a relevantly reduced ripple of the regulated DC voltage or current provided in output to a supplied load. The method includes sensing the difference between the error signal and the burst-stop threshold at the beginning of a burst period. If the error signal has surpassed (either upwards or downwards) the burst-stop threshold, the method sets the switching stage in a high impedance state at a new active edge of a clock signal, keeps the switching stage in the high impedance state for an integer number of cycles of the clock signal, and re-enables the switching stage to switch the energy tank circuit up to the end of the burst period.

Abstract: A DC/DC converter, a power converter and a control method thereof are disclosed, wherein the DC/DC converter includes an output circuit, a rectangular wave generator, a resonant tank, a detection unit and a control unit. The output circuit has a load. The rectangular wave generator converts an input voltage into driving pulses. The resonant tank provides a first voltage based on the driving pulses for the output circuit. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls the rectangular wave generator in a hiccup mode to reduce a ratio of a work period to a stop period, or makes that number of the driving pulses within the current work period is less than the number of the driving pulses when a duty ratio is 50%.

Abstract: A DC/DC converter, a power converter and a control method thereof are disclosed, where the DC/DC converter includes an output circuit having a load, a rectangular wave generator having a bridge arm, a resonant tank, a detection unit and a control unit. The bridge arm includes a first and a second switches connected each other. The detection unit detects a signal related to a state of the load. When the state of the load is a light-load or a no-load, the control unit controls ON/OFF state of the first and second switches by pulse width modulation mode to convert an input voltage into at least one rectangular wave for the resonant tank. A duty ratio of the first switch is within a first or second predetermined range, and a duty ratio of the second switch is complementary to the duty ratio of the first switch, whereby a voltage gain of the DC/DC converter is greater than 1.

Abstract: The present invention relates to a power converter (90) and a method of operating same. There are numerous advantages to operating power converters using a series resonant converter (1, 21). This approach is particularly suitable for minimizing switching losses in the power converter when it is operated at high frequency. However, there are problems with the known converters in that they are prone to generate noise in the acoustic spectrum due to the fact that the converter stages are often operating at different frequencies. The present invention relates to a power converter and a method of operating same that enables the operating frequency of the converter to be controlled by a control circuit over a predetermined range of the resonant frequency. This allows reduction in acoustic noise generation and facilitates frequency smearing that will in turn reduce spectral peaks. This is achieved while maintaining output ripple within acceptable ranges.

Abstract: In a switching power supply apparatus, when it is detected at time t1 that a voltage Vis has exceeded a first threshold Vth1, a timer counting a period of time T1 is started, and the number times the input voltage Vis does not exceed Vth1 is started to be counted. When the timer expires before the count reaches a predetermined number, a first overcurrent protection operation is performed. When it is detected at time t2 that Vis has exceeded a second threshold Vth2, a second overcurrent protection operation is immediately performed. As a result, appropriate overcurrent protection is performed in accordance with the operating state of a load.

Abstract: In a switching power supply device, a partition portion that includes a slit divides a winding portion of a bobbin. A primary winding of a transformer is wound to a height h1 in a first section, and a secondary winding is wound to a height h2 in a second section. A low side drive winding and a high side drive winding are wound around the primary winding to a height h3 with the high side drive winding being located toward the secondary winding.