Abstract: A power converter controller includes a primary controller and a secondary controller. The primary controller is coupled to receive one or more request signals from the secondary controller and transition a power switch from an OFF state to an ON state in response to each of the received request signals. The primary controller is coupled to detect a turn-off condition when the power switch is in the ON state and transition the power switch from the ON state to the OFF state in response to detection of the turn-off condition. The secondary controller is galvanically isolated from the primary controller. The secondary controller is coupled to transmit the request signals to the primary controller and control the amount of time between the transmission of each of the request signals.

Abstract: The present invention relates to a switch controller and a converter having the same. The converter according to the present invention includes a power transfer device that transmits input power to an output terminal as output power, a power switch connected to a first end of the power transfer device and that controls power transmission of the power transfer device, and a switch controller that controls switching operation of the power switch. The switch controller receives an output voltage detection signal corresponding to an output voltage according to the power transmitted from the power transfer device, generates a duty control signal corresponding to a difference between the output voltage detection signal and a reference signal for controlling the output voltage, and determines turn-on/off of the power switch by using the duty control signal, and a DC gain of a feedback transfer function between the reference signal and the output voltage has a constant value.

Abstract: A transformer capable of suppressing common mode current and a power converter thereof are provided. The transformer comprises a primary winding, a secondary winding, a magnet core and a shielding winding layer. The shielding winding layer has a first shielding winding and a second shielding winding. A voltage jump direction of the first shielding winding is constantly opposite to that of the second shielding winding. The shielding winding layer is coupled to a static terminal coupled with the primary winding or the secondary winding.

Abstract: A circuitry includes first, second, and third switching elements, first and second storage inductors, two connector pairs, and first and second intermediate potential points. The second storage inductor includes first and second windings. The first intermediate potential point is connected to a first connector of the first connector pair via the first storage inductor, to the second connector of the first connector pair via the third switching element, and to the second intermediate potential point. The second intermediate potential point is connected to the first connector of the second connector pair via a series connection of the first switching element and the first winding of the second storage inductor, and to the second connector of the second connector pair via a series connection of the second switching element and the second winding of the second storage inductor.

Abstract: A dual-mode circuit for the control of an AC/DC power converter is disclosed. An example dual-mode controller circuit generates a waveform that drives a switch on or off and controls the power converter. The controller circuit in addition to power factor correction (PFC) circuitry includes a critical conducting mode (CrM) module as well as a discontinuous conducting mode (DCM) module configured to generate waveforms adapted for CrM and DCM operation of a power converter. The circuit includes a node for receiving a feedback signal of a voltage or a current. Based on the received signal, one of the modules is selected at a time to supply the waveform at the output of the dual-mode controller. An example of the output waveform is a series of pulses that are configured to drive the switch that controls the transfer of power between input and output of the power converter.

Abstract: System and method for regulating an output current of a power conversion system. An example system controller for regulating an output current of a power conversion system includes a driving component, a demagnetization detector, a current-regulation component, and a signal processing component. The driving component is configured to output a drive signal to a switch in order to affect a primary current flowing through a primary winding of the power conversion system. The demagnetization detector is configured to receive a feedback signal associated with an output voltage of the power conversion system and generate a detection signal based on at least information associated with the feedback signal. The current-regulation component is configured to receive the drive signal, the detection signal and a current-sensing signal and output a current-regulation signal based on at least information associated with the drive signal, the detection signal, and the current sensing signal.

Abstract: A control circuit for a power converting circuit includes a multifunctional pin, a pulse-width-modulation (PWM) signal generating circuit, a voltage detecting circuit and a zero current detecting circuit. The voltage detecting circuit detects a signal on the multifunctional pin. When the signal on the multifunctional pin is greater than a predetermined value, the voltage detecting circuit configures the PWM signal generating circuit to intermittently conduct a current switch of the power converting circuit. The zero current detecting circuit detects the signal of the multifunctional pin to determine the conduction status of the current switch. When the signal of the multifunctional pin is less than the predetermined value, the voltage detecting circuit configures the PWM signal generating circuit to turn off the current switch.

Abstract: System and method for regulating a power conversion system. An example system controller for regulating a power conversion system includes a first controller terminal associated with a first controller voltage and coupled to a first transistor terminal of a first transistor, the first transistor further including a second transistor terminal and a third transistor terminal, the second transistor terminal being coupled to a primary winding of a power conversion system, a second controller terminal associated with a second controller voltage and coupled to the third transistor terminal, and a third controller terminal associated with a third controller voltage. The first controller voltage is equal to a sum of the third controller voltage and a first voltage difference. The second controller voltage is equal to a sum of the third controller voltage and a second voltage difference.

Abstract: In accordance with an embodiment, a method of calibrating a power supply includes coupling a reference load to an output of the power supply, setting an output voltage of the power supply to a first output voltage, measuring a current delivered to the reference load, and determining a current metric based on the measuring. The output voltage of the power supply is increased until the determined current metric crosses a first threshold, which occurs when the output of the power supply is at a second output voltage, and the power supply it set to operate at the second output voltage.

Abstract: Embodiments include circuits and methods to determine peak current for current regulation. A control signal circuit monitors a current on the primary side of a transformer based a turn on time of a switch coupled to the primary side. The control signal circuit determines whether the monitored current exceeds an over-current protection threshold, and determines a duration that the monitored current exceeds the over-current protection threshold. The control signal circuit determines a peak primary current in the primary side based on the over-current protection threshold, the duration that the monitored current exceeds the over-current protection threshold, and the turn on time of the switch. The control signal circuit controls the turn on time for the switch based on the determined peak primary current.

Abstract: A switching power converting apparatus includes a coil unit, a bipolar junction transistor (BJT) controlling power transfer through the coil unit, and a current sensing resistor sensing a current flowing through the BJT so as to produce a sensed voltage thereacross. A switching controller includes a current source supplying a first current, a current generating module generating, based on an input voltage associated with the sensed voltage, a second current, which is proportional to the current flowing through the BJT, a multiplexing module selecting one of the first and second currents as an output current, and a driving module outputting, based on the output current, a driving current, which is proportional to the output current, to the BJT to thereby conduct the BJT.

Abstract: A switched-mode power supply (SMPS) capable of catching radiated electromagnetic interference (EMI) and using its energy is provided. The SMPS includes a specific component, an antenna, a rectifier, and an energy storage capacitor or a rechargeable battery. The specific component generates radiated EMI. The antenna is disposed on or embedded in the specific component, in which the frequency range of the antenna corresponds to the frequency band of the radiated EMI generated by the specific component. The rectifier is electrically connected with a terminal of the antenna. The energy storage capacitor or the rechargeable battery is electrically connected with the rectifier. The invention may simplify the design of circuits for suppressing radiated EMI to reduce cost, and achieve the purpose of power saving by recycling and reuse dissipated energy.

Abstract: A method and system for controlling a cascaded converter has an upstream converter and a downstream converter coupled in series. An energy storage element is provided between the two converters for providing constant energy and to respond to a load step in the load of the system. An upstream controller is connected to the output of the downstream controller to control the duty cycle of the upstream converter as a function of the duty cycle of the downstream controller. The upstream converter controls the duty cycle of the upstream converter in order to maintain the duty cycle of the second converter at a substantially constant reference value. This control of the converters allows for reduction of the energy storage requirements of the cascaded system.

Abstract: A switching circuit (400) comprising an inductive component (406) including at least one winding; and a switch (404) is configured to transfer power from a voltage source (402) to the inductive component (406) in accordance with a switch control signal (412). The switching circuit (400) also comprises a controller (408) configured to integrate the voltage across the inductive component (406) in order to generate a signal representative of magnetic flux in the inductive component (406); and use the signal representative of the magnetic flux in the inductive component to account for a peak magnetization current value in order to control the switch (404).

Abstract: In certain embodiments, the present invention provides a compound power converter in which the majority of power passes from input to output through only a single stage of power conversion. At least one embodiment includes a main converter with an auxiliary output. The auxiliary output energizes a reservoir that provides input power for a supplemental converter capable supplying the main output. The supplemental converter improves regulation and can provide holdover power for Power Factor Correction (PFC) or Uninterruptible Power Supply (UPS) operation.

Abstract: A power supply device may include a transformer having a primary winding receiving a rectified alternating current (AC) input power and a secondary winding electromagnetically coupled to the primary winding to supply power to a load, an auxiliary switch selectively providing the rectified AC input power to the primary winding, and a limitation controlling unit controlling the auxiliary switch based on a voltage level of the AC input power.

Abstract: In a switching power supply device which intermittently executes a switching operation, a power loss which occurs in resumption of the switching operation is reduced. A semiconductor device works as a control circuit for the switching power supply device, and includes: an intermittent oscillation control circuit which alternately gives an instruction for execution and suspension of the switching operation of a switching element; a bottom detecting circuit which detects a bottom of a ringing voltage that develops when the switching element is OFF; a bottom-monitoring time period timing circuit which times a bottom-monitoring time period starting as soon as the instruction for the execution of the switching operation is given; and a turn-on control circuit which turns ON, before the timing of the bottom-monitoring time period ends, the switching element only when the bottom of the ringing voltage is detected.

Abstract: An inverter and driving method of the inverter are disclosed. The inverter includes an active clamp forward (ACF) converter and a flyback converter. One of a forwarding operation of delivering current from a primary side to a secondary side by using the ACF converter and a backwarding operation of delivering current from the secondary side to the primary side by using the flyback converter is selected to generate a rectified AC.

Abstract: A method for operating a DC-DC converter. The method comprises: matching, based on a turns ratio of a transformer of the DC-DC converter, a primary side capacitance of the DC-DC converter and a secondary side capacitance of the DC-DC converter to result in a matched capacitance; and operating the DC-DC converter with at least one operating parameter set to cause a primary current to oscillate between a peak value and zero such that a valley of the primary current coincides with a zero crossing of a secondary switching element voltage.

Abstract: An active damper and a power supply according to exemplary embodiments include: a damper resistor coupled to an input voltage; a damper switch coupled in parallel with the damper resistor; and a capacitor to which a reset current generated by a leading edge of the input voltage flows. The damper switch is turned off by the reset current.

Abstract: A switching power source is provided, which includes, a transformer, a switching unit configured to switch a voltage supplied to a primary side of the transformer, and an output unit configured to output a voltage generated at a secondary side of the transformer, wherein a switching cycle of the switching unit is set to be a predetermined period of time when the output unit outputs a first voltage, a first period of time and a second period of time are set to be longer than the predetermined period of time and are set to be different from each other.

Abstract: A switching power supply apparatus includes: an input terminal; an output terminal; a switching element; an input and output converting unit which converts input voltage applied through the switching element into output voltage to supply output power to a load; an output voltage feedback unit which outputs a feedback signal, based on the output voltage; a switch current detecting unit which detects current flowing through the switching element; an oscillating frequency setting unit which sets the switching frequency of the switching element, based on the feedback signal; a peak current setting unit which controls turn-off of the switching element by setting a current threshold such that a switch current peak (i) is constant regardless of a change in the output power and (ii) increases as the input voltage increases; and a switching control unit which controls switching operation of the switching element.

Abstract: A switched mode power converter controller outputs a switch control signal for a switch, receives sensed voltage and primary current input signals, and includes a constant current mode controller to process voltage input signals and generate output control signals for controlling converter peak current and/or switching frequency operational; a constant voltage mode controller processes the voltage input signal and generates output control signals for converter peak current and/or switching frequency operational parameters; a primary peak current adjuster processes primary current input and output control signals from the current and voltage mode controllers to configure the switch control signal to turn off the switch; a switching frequency adjuster processes output control signals from the current and voltage controllers to configure the switch control signal to turn on the switch.

Abstract: An isolated flyback converter having temperature compensation (TC) uses primary side sensing and an output diode, the output diode having a variable voltage drop related to its temperature. A feedback voltage VFB, proportional to the output voltage VOUT, in a feedback loop is compared to a fixed reference voltage VREF for setting a duty cycle of a power switch, wherein VFB is caused to approximately equal VREF. A TC circuit has a voltage source configured to generate a proportional-to-absolute-temperature voltage VPTAT, wherein VPTAT is at approximately VREF at a calibration temperature T0 and rises as a temperature exceeds T0. The voltage source is connected to the VFB node via a TC resistor RTC, so that at T0 no current flows through RTC. Therefore, the selection of the optimal RTC does not affect the selection of a scaling resistance for generating VFB. The current through RTC at elevated temperatures compensates VOUT.

Abstract: A power converter system, method and device powers a load when coupled to the load and draws a quasi-zero amount of power from the power supply when not coupled to the load. The power converter system maintains an output voltage such that the power converter system is able to properly “wake-up” when a load is coupled by intermittently operating the power converter for a preselected number of cycles when it is detected that the output voltage has fallen below a threshold level.

Abstract: The invention relates to an apparatus and method for tracking energy consumption. An energy tracking system comprises at least one switching element, at least one inductor and a control block to keep the output voltage at a pre-selected level. The switching elements are configured to apply the source of energy to the inductors. The control block compares the output voltage of the energy tracking system to a reference value and controls the switching of the switched elements in order to transfer energy for the primary voltage into a secondary voltage at the output of the energy tracking system. The electronic device further comprises an ON-time and OFF-time generator and an accumulator wherein the control block is coupled to receive a signal from the ON-time and OFF-time generator and generates switching signals for the at least one switching element in the form of ON-time pulses with a constant width ON-time.

Abstract: Example embodiments of the systems and methods of CCM primary-side regulation disclosed herein subtract an estimate of the secondary IR drop from each output voltage sample. This allows a fixed sample instant to be set (with regard to the beginning of the off or flyback interval), and removes the need to hunt for or adjust to an optimum sample instant, or one with minimum IR drop error. The estimate of the IR drop may be adjusted on a cycle-by-cycle basis, based on the commanded primary peak current, knowing that the peak secondary current will be directly proportional by the turns ratio of the transformer. For improved accuracy, an adjustment may be made for the decay of secondary current during the delay to the sample instant, if the inductance value is known.

Abstract: A control circuit of a switching converter includes a current detection comparator for comparing a detection voltage corresponding to a voltage drop of a detection resistor with a reference voltage and generating a peak current detection signal asserted when the detection voltage reaches the reference voltage, a driving logic unit for generating a pulse signal indicating a turn-on/off operation of a switching transistor and changing the pulse signal to an OFF level indicating the turn-off operation of the switching transistor when the peak current detection signal is asserted, a driver for driving the switching transistor based on the pulse signal, and a reference voltage setting unit for measuring time (TRECT) for which a current flows through a secondary coil and a switching period (T) of the switching transistor and adjusting the reference voltage (VREF) according to an equation: VREF=K×T/TRECT where K is a coefficient.

Abstract: Embodiments of the present invention describe a voltage converter and a method for operating the voltage converter. In one embodiment the voltage converter includes a primary path configured to generate a pulse modulated voltage or current from an input direct current (DC) voltage, a transformer arrangement with m?1 primary windings and n?2 secondary windings inductively coupled together, the m primary windings being connected to the primary path, and a secondary path configured to output a pulsed direct current (DC) voltage or current, wherein the secondary path includes n capacitors connected in series and n secondary controllable semiconductor switches, and each of the n secondary windings is connected via at least one of the secondary controllable semiconductor switches to at least one of the capacitors.

Abstract: A single-stage AC-DC power converter for powering a load at a substantially constant current, and related methods and systems. The AC-DC power converter includes a high power factor correction (PFC) circuit configured in a flyback topology and operating in transition mode. The flyback PFC circuit outputs a direct current (DC) voltage and a DC current. The PFC circuit further includes a flyback transformer and a switch circuit that selectably toggles the substantially constant output current provided to the load between a first and a second, preset constant current. The secondary windings of the flyback transformer are split into two sections, and the switch circuit toggles the two sections of the secondary windings between a series and a parallel configuration to provide the first and second, preset constant currents. The switch circuit includes a switch and three, fast Schottky diodes.

Abstract: A single-stage AC-DC power converter for powering a load at a substantially constant current, and related methods and systems. The AC-DC power converter includes a high power factor correction (PFC) circuit configured in a flyback topology and operating in transition mode. The flyback PFC circuit has a PFC controller and is configured to draw an input AC current from an AC power supply. The input AC current has a first total harmonic distortion (THD). The flyback PFC circuit outputs a DC current to the load. The PFC controller is configured to sense a rectified input voltage. By multiplying the rectified input voltage sensed by the PFC controller, the input AC current drawn by the flyback PFC circuit has a second, much improved THD, which is achievable without the need of an expensive PFC controller. The rectified input voltage sensed by the PFC controller is multiplied using a Zener diode ladder.

Abstract: A method for sensing an output current Iout of the fly-back converter has steps of sensing a voltage US of the switching node to obtain a time period TSW of a switching cycle of the fly-back converter and a time period TOFF of a OFF stage of the switching cycle; and then calculating the output current Iout according to a formula I out = k ? T OFF 2 T SW , wherein k is a predictable constant. By the method, a user just need to sense the voltage US of the switching node of the fly-back converter, and then the output current Iout of the fly-back converter is obtained by the formula without using a sensing resistor to sense any current in the fly-back converter.

Abstract: A two-stage AC-DC power converter for powering a load at a substantially constant current, and related methods and systems. The first stage of the AC-DC power converter includes a conventional power factor correction (PFC) circuit that outputs a direct current (DC) voltage and a DC current. The second stage of the AC-DC power converter includes a low voltage flyback circuit that receives the DC voltage and the DC current. The low voltage flyback circuit includes a flyback transformer and a switch circuit that selectably toggles the substantially constant output current provided by the low voltage flyback circuit to the load between a first and a second, preset constant current. The secondary windings of the flyback transformer are split into two sections, and the switch circuit toggles the two sections of the secondary windings between a series and a parallel configuration to provide the first and second, preset constant currents.

Abstract: Disclosed herein are an AC-DC converter in which an inductor of boost PFC and a flyback transformer are integrated in one and a method of preventing a magnetic density from being saturated by shifting a phase. The integrated magnetic circuit according to an exemplary embodiment of the present invention includes: a power factor correction stage (PFC-stage) including a boost inductor; and a flyback transformer including a primary winding and a secondary winding, wherein the boost inductor and the primary winding of the flyback transformer and the secondary winding of the flyback transformer are wound around a single core.

Abstract: A two-stage AC-DC power converter for powering a load at a substantially constant current, and related methods and systems. The first or front end stage of the AC-DC power converter includes a buck topology power factor correction (PFC) circuit and a PFC controller. The second stage of the AC-DC power converter includes a conventional isolation and regulator circuit configured to receive the DC voltage and DC current output by the buck PFC and then to provide the substantially constant current to the load. By multiplying the rectified input voltage sensed by the PFC controller, the input AC current drawn by the buck PFC circuit has a much improved total harmonic distortion (THD), which is achievable without the need for using an expensive PFC controller. The rectified input voltage sensed by the PFC controller is multiplied using a Zener diode ladder.

Abstract: The present application discloses a LED driver including: a first and a second auxiliary windings connected in series with each other; a first rectifying device coupled with a terminal of the first auxiliary winding while the other terminal is coupled with the second auxiliary winding; a second rectifying device coupled with a terminal of the second auxiliary winding; a first voltage regulator coupled with the first rectifying device; an unidirectional conducting device having a positive and a negative terminals; and a DC output terminal coupled with the negative terminal of the unidirectional conducting device and configured to provide required DC electricity to a control circuit in the LED driver. The LED driver can guarantee that Vcc voltages provided under a heavy or light load state can always meet the DC power supplying requirements of respective control devices in the driver and meanwhile losses can be reduced.

Abstract: A controller integrated circuit (IC) for controlling a power converter uses one or more IC pins having plurality of functions such as configuration of a parameter supported by the controller IC and shutdown protection. Several different functions may be supported by a single IC pin, thereby reducing the number of pins required in the controller IC and also reducing the cost of manufacturing the controller IC. The controller IC may also share a comparison circuit among different pins and the different functions provided by those pins. Use of a shared comparison circuit further reduces the cost of manufacturing the controller IC without sacrificing the performance of the IC.

Abstract: Transformers and methods of constructing transformers are disclosed. In one embodiment, a method of constructing a transformer includes wrapping a first primary winding around a core, wrapping a secondary winding around the core, and wrapping a second primary winding around the core. The first primary winding traverses substantially an entire circumference of the core in a first circumferential direction. The secondary winding includes a first half and a second half. The first half traverses substantially the entire circumference of the core in the first circumferential direction, and the second half traverses substantially the entire circumference of the core in a second circumferential direction opposite the first circumferential direction. The second primary winding traverses substantially the entire circumference of the core in the second circumferential direction.

Abstract: An insulated power supply apparatus is for a power conversion circuit including at least one series connection of an upper arm switching element and a lower arm switching element connected in series to each other. The insulated power supply apparatus includes an upper arm and lower arm transformers for supplying a driving voltage to the upper arm and lower arm switching elements, respectively, and performs control such that the output voltage of a specific one of the secondary coils of the upper arm and lower arm transformers is kept at a target voltage.

Abstract: A controller of a switching power converter employs a dynamically adaptive power supply regulation approach that improves low-load and no-load regulation to achieve ultra-low standby power in a switching power converter. Under ultra-low load conditions when a deep-deep pulse width modulation (DDPWM) is applied, the controller decreases the actual on-time of the power switch of the switching power converter by decreasing the “on” duration of the control signal used to turn on or off the power switch, until the “on” duration of the control signal reaches a minimum value. To further reduce the on-time of the power switch, the controller reduces the power applied to the power switch to turn on the switch more slowly, while maintaining the “on” duration of the control signal at a minimum value. The minimum value of the “on” duration of the control signal and the minimum power applied to the switch are dynamically controlled.

Abstract: A high frequency cathode heater supply for a microwave source includes a SMPS inverter and an isolation transformer having a primary winding arranged to be powered by the SMPS inverter, a monitor winding passing through primary core assemblies of the primary winding and a secondary winding arranged for connection to the cathode heater. A current monitor is arranged to monitor a current in the primary windings. Signal processing modules are arranged to receive a first input signal from the monitor winding indicative of a voltage across the cathode heater and a second input signal from the current monitor indicative of a current through the cathode heater. The signal processing modules are arranged to output a control signal to the SMPS inverter to control power supplied to the cathode heater dependent on a monitored resistance of, or monitored power supplied to, the cathode heater as determined from the first input signal and the second input signal.

Abstract: A control integrated circuit for controlling a switch power supply, including: a voltage collecting module, configured to collect a feedback voltage based on an output voltage of the switch power supply; an error amplifying module, configured to compare the feedback voltage with a reference voltage and generate an error voltage; a time collecting module, configured to obtain a degaussing time signal based on the feedback voltage; and a constant voltage and current module, configured to collect a peak current feedback signal of a switch transistor, generate a control signal based on the error voltage, the degaussing time signal and the peak current feedback signal, wherein the control signal is for controlling an operating frequency and a duty ratio of the switch transistor, and control the switch transistor according to the control signal.

Abstract: The disclosure concerns a switched-mode power supply comprising a module for charging and discharging an energy store including an electrical transformer. The device provides high configuration flexibility.

Abstract: A low-voltage power supply apparatus (900A) providing power to an neutral-less two-wire electronically controlled switch, including a first power supply (901) having a first DC bus (910+, 910?) electronically coupled to a rectifier bridge (906) and a first flyback converter (991). The rectifier bridge receives an AC signal from an AC source and provides a first DC voltage at the first DC bus, the first flyback converter receives the DC voltage and outputs a first low-voltage signal (Vout). A second power supply (905) having a second DC bus (909+, 909?) is electronically coupled to a controllable rectifier bridge (966) and a second flyback converter (971). The controllable rectifier bridge receives the AC signal from the AC source and provides a second DC voltage at the second DC bus. The second flyback converter receives the second DC voltage and outputs a second low-voltage signal (Vout).

Abstract: A controller for a switched mode power supply (SMPS) is provided. The SMPS is equipped with a transformer having a primary side winding, a secondary winding, and an auxiliary winding. The controller includes a detection circuit for detecting a transition from a first output load condition to a second output load condition of the SMPS and a control circuit coupled to the detection circuit and being configured to output one or more control signals in response to the detected output load transition. Depending on the embodiment, the one or more control signals include a first control signal for turning on a power switch to cause a current flow in a primary winding of the SMPS and/or one or more second control signals for turning off one or more functional circuit blocks in the controller.

Abstract: The present invention provides an off time control method and switching regulator using it. The current flowing through a switch is compared with a current threshold, and the switch is turned off if the current flowing through the switch is larger than the current threshold. The off time of the switch is determined by the load. The current threshold is variable at light load to prevent generating the audible noise and improve the whole efficiency.

Abstract: The disclosed embodiments provide a system that operates a flyback converter. During operation, the system senses an input voltage for the flyback converter. Next, the system uses the input voltage to determine a negative peak current that enables zero voltage switching for a primary switch in the flyback converter. Finally, the system uses the negative peak current to perform the zero voltage switching for the primary switch based on the input voltage, wherein the negative peak current reduces a power loss of the flyback converter.

Abstract: A system for driving a piezoelectric load includes a direct current (DC) voltage source and a bi-directional DC-to-DC converter having a primary side coupled to the DC voltage source and a secondary side and comprising a control input configured to receive a first control signal configured to control conversion of a first voltage on the primary side of the bi-directional DC-to-DC converter to a second voltage on the secondary side of the bi-directional DC-to-DC converter. The driver system also includes a capacitor coupled to the secondary side of the bi-directional DC-to-DC converter and configured to remove a DC offset of the second voltage and includes a reactive load having a first terminal coupled to the capacitor and a second terminal coupled to the secondary side of the bi-directional DC-to-DC converter.

Abstract: A power conversion system includes a first switching DC-DC converter circuit including a first switching device, a second switching DC-DC converter circuit connected in parallel with the first switching DC-DC converter circuit and including a second switching device, and a snubber capacitor connected in parallel with each of the first switching device and the second switching device. The power conversion system is configured such that a frequency of driving the first switching DC-DC converter circuit is higher than a frequency of driving the second switching DC-DC converter circuit, and an equivalent series inductance of a closed circuit including the first switching device and the snubber capacitor is smaller than that of a closed circuit including the second switching device and the snubber capacitor.

Abstract: A power supply apparatus having multiple outputs which includes a transformer, a first output circuit generating a first output voltage with respect to a power transferred to a secondary side of the transformer, and a first output controller generating a first control signal for controlling a power supply provided to a primary side of the transformer. The power supply apparatus further includes a second output circuit generating a second output voltage with respect to the power transferred to the secondary side of the transformer and a second output controller controlling an output of the second output voltage, wherein the second output circuit includes a second switch performing a switching operation on current flows of the second output circuit, and the second output controller controls the switching operation of the second switch according to the first control signal and the second output voltage.