Abstract: An apparatus includes: a power supply circuit including at least a first stage having a push-pull circuit topology, the first stage including at least one transformer that isolates a primary side of the first stage from a secondary side of the first stage; a clamp circuit coupled to a center tap of the transformer, the clamp circuit including a first element that stores energy, and a second element that controls a flow of current between the center tap of the transformer and the first element; and a control module receiving power from the clamp circuit. The control module is configured to provide control signals to one or more elements of the power supply circuit.

Abstract: A device and a method for operating a low power switch mode power supply, where DC input power is converted to AC power by an oscillator, which AC power is transformed to an AC voltage and AC current, which output power is converted into DC power, where the DC voltage is used as a feedback signal for controlling the oscillator. It is the objective of the invention to reduce a standby power consumption of power consuming devices. The oscillator comprises a first and a second current loop, which first current loop generates an activation current for the second current loop, where the primary coil of a transformer is part of the second current loop, and where the second loop comprises a current/voltage measuring system and generates increasing current in the second current loop and closes the current flow in the second current loop.

Abstract: The present invention relates to a switch control circuit that controls a switching operation of a power switch circuit that includes cascode-coupled first and second transistors. A switch control circuit includes a first zener diode coupled between a gate of the first transistor and a first end of a capacitor supplying a power voltage and a second zener diode coupled to a gate and a source of the first transistor, and a first resistor coupled between the first zener diode and the second zener diode.

Abstract: A multi-stage power converter includes a pre-regulator circuit configured to provide a regulated output voltage, at least one DC/DC converter, and a control circuit coupled to the pre-regulator circuit and the DC/DC converter. The DC/DC converter is configured to provide an output voltage and an output current to a load. The DC/DC converter includes an input, an output, and at least one power switch. The input of the DC/DC converter is coupled to the pre-regulator circuit. The control circuit is configured to regulate the output voltage of the DC/DC converter and vary the regulated output voltage of the pre-regulator circuit as a function of the output current of the DC/DC converter.

Abstract: A DC power supply (1) having a series regulator (2) for generating a fixed output DC voltage (VCC) at a variable input AC voltage (VAC) with low power loss. For this purpose, the DC power supply (1, 101, 201, 301) has a transformer (3, 103) having at least two auxiliary windings (W1, W2) having different numbers of windings that can each be connected via a switching device (4, 104, 204, 304) to the series regulator (2). Switching is effected such that the power loss is kept as low as possible.

Abstract: Switching regulator methods and systems for supplying output current at a regulated voltage level to a load. The regulator has a primary side that is galvanically isolated from a secondary side. The regulator includes a transformer having a primary winding on the primary side and a secondary winding on the secondary side, coupled to a load. A switch, coupled to the primary winding, controls current flow through the primary winding. A first feedback control loop, responsive only to primary side signal values, regulates a constant average voltage at the output node. An optional second feedback control loop, responsive only to primary side signal values, reduces voltage ringing at the output node.

Abstract: A step down power converter include a switch, an inductor, a diode, a capacitor, and a winding magnetically coupled to the inductor. The diode, the inductor and the capacitor are coupled in series, and the transistor, the coupled winding and the capacitor are coupled in series. An output voltage Vout is supplied across the capacitor. When the switch is ON, energy is transferred from an input supply voltage to a load coupled across the capacitor, and current flows through the coupled winding thereby storing energy in the winding. When the switch OFF, current does not flow through the coupled winding, but the energy stored in the winding induces current in the magnetically coupled inductor, thereby delivering energy from the winding to the load.

Abstract: An electric power conversion system includes: a primary electric power conversion circuit including primary right and left arms; a secondary electric power conversion circuit including secondary right and left arms; and a control circuit controlling transfer of electric power between the primary and secondary electric power conversion circuits by magnetically coupling a primary coil to a secondary coil. The control circuit sets an interphase difference in switching between right and left arm lower transistors in the primary electric power conversion circuit and an interphase difference in switching between right and left arm lower transistors in the secondary electric power conversion circuit on the basis of off times of the primary and secondary electric power conversion circuits such that a phase difference between terminal voltage waveforms of the primary and secondary coils is 0 and duty ratios of the terminal voltage waveforms are equal to each other.

Abstract: The present invention relates to a hold-up time expansion circuit and a converter including the same. The hold-up time expansion circuit controls switching frequency of at least one switch according to the input voltage of the converter. The converter is dependent on the switching frequency that is controlled by the hold-up time expansion circuit, and controls the duty of at least one switch according to the feedback signal of the output voltage.

Abstract: A single stage power factor correction power supply consists of two transformers: a main transformer and an auxiliary transformer (forward transformer). The main transformer transfers energy from the primary circuit to secondary circuit. The auxiliary transformer is used to correct input current waveform. The advantage of this design over the two stages power supply is that the voltage across storage capacitor can be designed to be only slightly higher than the peak value of the rectified input voltage. Therefore, it uses less energy to correct input current waveform and less EMC problem because it has less current through the inductor than two stage PFC power supply.

Abstract: A forward-flyback DC-DC converter topology includes a transformer, a main switch, a clamp circuit, first and second rectifying switches, an LC resonant circuit and an output capacitor; a primary winding of the transformer and the main switch are connected in series between a first input terminal and a second input terminal, the clamp circuit constituted by a clamp capacitor and a clamp switch connected in series is connected in parallel with the primary winding or with the main switch, a secondary winding of the transformer includes a forward winding and a flyback winding, a terminal of the primary winding through which current flows into is a dotted terminal of the primary winding, and a connecting mode of a secondary side of the transformer is: the dotted terminal of the forward winding being connected with a first output terminal via the first rectifying switch, a dotted terminal of the flyback winding being connected with a second output terminal via the second rectifying switch, the LC resonant circuit b

Abstract: A power converter includes a transformer having a primary winding and a secondary winding, a primary side circuit coupled to the primary winding, and a secondary side circuit coupled to the secondary winding and configured to output a substantially direct current (DC) output. The primary side circuit is configured to receive an input voltage and to switch the input voltage across the primary winding of the transformer. The secondary side circuit includes an active forward mode rectifier.

Abstract: A switching power source includes: a transformer; a semiconductor switching element that is provided at a primary side of the transformer; a rectifying-and-smoothing circuit that is provided at a secondary side of the transformer; a switching controller configured to perform a switching control to turn on-and-off the semiconductor switching element, wherein the switching controller comprises: a stoppage circuit configured to perform a stoppage process to stop the switching control when a first-level control signal is input, a restart circuit configured to restart the switching control when a second-level control signal different in its level from the first-level control signal, and a limiting circuit configured to limit, at the time of a start-up of the switching power source, a performance of the stoppage process performed by the stoppage circuit until an output voltage of the switching power source increases to a target voltage.

Abstract: The invention provides a DC to DC converting circuit, comprising: a transforming unit with a primary winding and a secondary winding; a bridge rectifier unit coupled to an input voltage, having a first output terminal and a second output terminal coupled to both side of the primary winding respectively; a first switch coupled between the input voltage and the first output terminal; a second switch coupled between the first output terminal and a ground terminal; a third switch coupled between the input voltage and the second output terminal; and a fourth switch coupled between the second output terminal and the ground terminal; an output unit paralleled to the secondary winding; and a clamping unit coupled to the input voltage and paralleled to the bridge rectifier unit, having an auxiliary switch coupled to the input voltage; and a clamping capacitor coupled between the auxiliary switch and the ground terminal; wherein the auxiliary switch is turned on when operation statuses of the first switch and the fourt

Abstract: A power supply circuit has an LLC converter stage for converting a DC voltage input into a DC voltage output, and at least one hysteretic converter stage. Each hysteretic converter stage has a DC voltage input coupled to the DC voltage output of the LLC converter stage, and a DC current output. The LLC converter stage lacks a feedback control, and is operated at its load independent point. A ripple on the DC voltage output of the LLC converter does not affect the output current of the hysteretic converter stage. The stable DC current output of the hysteretic converter stage is coupled to a load having one or more LED strings.

Abstract: Disclosed herein is an electric generating system using a solar cell, including: a DC/DC converter that converts output voltage generated from a solar cell into DC voltage and has a converter switching device; a snubber device that has a snubber switch clamping voltage applied to the converter switching device; and a control device that detects the voltage applied to the converter switching device and controls an operation of the snubber switch according to a detected voltage level applied to the converter switching device, thereby increasing the efficiency of the electric generating system using a solar cell while reducing switching loss and conduction loss.

Abstract: A converter arrangement, includes a DC/DC stage comprising a plurality of DC/DC converters. Each of the plurality of DC/DC converters is operable to receive one of a plurality of direct input voltages. The DC/DC stage is configured to generate an output voltage from the plurality of direct input voltages.

Abstract: A main transformer is arranged such that a load is connected to its secondary winding side. A first error amplifier generates a feedback signal that corresponds to the difference between a detection signal which indicates the electrical state of the load and a predetermined first reference voltage. A current generating resistor is arranged between a current generating transistor and a fixed voltage terminal. A second error amplifier is arranged such that the first input terminal receives the electric potential at a node that connects the current generating transistor and the current generating resistor, a predetermined second reference voltage is input to the second input terminal thereof, and the output terminal thereof is connected to the control terminal of the current generating transistor. An adjustment resistor is arranged between the output terminal of the first error amplifier and a node that connects the current generating transistor and the current generating resistor.

Abstract: In a switching control circuit, a length of a soft start period is set by a time constant of an external circuit that is connected to a soft start terminal of a switching control IC. After a voltage of the soft start terminal has reached a predetermined voltage at the termination of the soft start period, the on-pulse period of a first switching device is limited by a maximum value. When a Zener diode is connected between the soft start terminal and ground, the upper limit voltage of the soft start terminal is a Zener voltage and, hence, the maximum on-pulse period is limited by this voltage. As a result, the switching control circuit and a switching power supply apparatus, which have a soft start function and a power limiting function, are reduced in size and cost by limiting the number of terminals.

Abstract: A pulse scheme is used for load change detection in a switching mode power supply with low no-load power consumption. The pulse scheme includes a measurement pulse for determining a load condition or a no-load condition at the output. Generation of the measurement pulse results in sufficient energy transfer to the secondary side to accurately measure the output voltage via a reflected voltage on the primary side. Once in no-load operation mode, a reference pulse having a lower energy transfer than the measurement pulse is used to determine a baseline reflected voltage value that corresponds to a no-load condition. Successive detection pulses are then generated and corresponding reflected voltage measured and compared to the baseline reflected voltage. A change in the reflected value that exceeds a threshold value is indicative of a change in the no-load condition.

Abstract: A power converter circuit includes a transformer and a main switch controller by a primary side controller. A sensing circuit is implemented that senses the voltage at an auxiliary winding of the transformer while the main switch is ON. The auxiliary winding is another winding on the primary side of the transformer, magnetically coupled to the secondary winding and electrically isolated from the primary winding. When the voltage across the auxiliary winding reaches a predefined threshold voltage level, the main switch is switched OFF. The threshold voltage level is set at a value that minimizes an amount of energy transferred per pulse to the secondary side of the circuit while maintaining a minimum amount of energy transfer to enable output voltage sensing at the auxiliary winding.

Abstract: A DC/DC converter may include a power stage circuit, a pulse generator circuit, a flux density monitor, and power control logic. The power stage circuit includes an input, an output, and a transformer with a core. The power stage circuit may be configured to operate in a power transfer phase during which power is transferred from the input to the output and a reset phase during which flux density in the core of the transformer is reduced. The pulse generator circuit may be configured to generate pulses that regulate the output of the power stage circuit. The flux density monitor circuit may be configured to generate flux density information indicative of the flux density of the core of the transformer during both the power transfer phase and the reset phase. The power stage control logic may be configured to regulate the output of the power stage circuit based on the pulses and to prevent the core of the transformer from saturating based on the flux density information.

Abstract: An active clamp DC-DC converter includes a transformer having a primary coil and a secondary coil, a main switching device connected in series to the primary coil of the transformer so that the main switching device and the primary coil are connected in parallel to a DC power source, a reset capacitor, a reset switching device connected in series to the reset capacitor so that the reset switching device and the reset capacitor are connected in parallel to the primary coil of the transformer, a rectifying circuit connected to the secondary coil of the transformer, a smoothing circuit connected to the rectifying circuit, and a control circuit adjusting a dead time that elapses from the time when the reset switching device is turned off until the time when the main switching device is turned on, based on a voltage across the main switching device.

Abstract: A single switch PFC power supply (including forward and fly-back power supply) in single stage has two transformers: one forward transformer, one main transformer. The main transformer transfers electrical power from the primary circuit to secondary circuit. The forward transformer is used to correct input current waveform. The two transformer's primary windings are connected in series. An extra winding of the forward transformer, a capacitor and two diodes are formed a no loss snubber circuit to enhance the efficiency of the power supply.

Abstract: An isolated DC-DC converter includes a transformer, a main switch, an active clamp circuit and a control unit. The transformer has a primary winding. The main switch and the active clamp circuit are connected to the primary winding. The active clamp circuit has an auxiliary switch and a clamp capacitor connected in series. The control unit is provided for controlling the main switch and the auxiliary switch. The control unit performs a soft start operation of the converter before a normal operation. The control unit performs anti-saturation control before starting the soft start operation. The anti-saturation control includes an act of controlling the main switch and the auxiliary switch so that the auxiliary switch performs ON-OFF operation with the main switch kept OFF until voltage of the clamp capacitor drops below a level at which the transformer is to be magnetically saturated after starting the soft start operation.

Abstract: An arrangement for improved operability of a high temperature fuel cell device at higher fuel cell voltage values than nominal voltage values, each fuel cell in the fuel cell device including an anode side, a cathode side, and an electrolyte between the anode side and the cathode side, and the arrangement includes means for determining temperature information of the fuel cells and main power converter for loading fuels cells at least up to their rated power level.

Abstract: 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.

Abstract: A method of controlling a switching mode power converter enables zero voltage switching by forcing a voltage across the main switch to zero. This is accomplished by sensing when a current on the secondary side of the power converter drops to zero, or other threshold value, and then generating a negative current through the secondary winding in response. The negative secondary current results in a corresponding discharge current in the primary winding, which reduces the voltage across the main switch. The voltage across the main switch is monitored such that when the voltage reaches zero, or other threshold value, the main switch is turned ON. In this manner, the circuit functions as a bi-directional current circuit where a forward current delivers energy to a load and a reverse current provides control for reducing the voltage across the main switch to enable zero voltage switching.

Abstract: There is provided a single-stage forward-flyback converter capable of increasing power factor and power conversion efficiency while performing power factor correction and constant current control in a single-stage circuit. The converter includes: a power converting unit including a transformer having a primary winding receiving input power and a secondary winding magnetically coupled to the primary winding to receive power induced thereto, and converting the input power in a forward scheme and a flyback scheme; a balancing unit maintaining balance between a power level by the forward scheme of the power converting unit and a power level by the flyback scheme thereof; and a path providing unit clamping the power by the forward scheme of the power converting unit and the power by the flyback scheme thereof to provide a power transfer path, wherein the power converting unit selectively operates the forward scheme according to a voltage level of input power.

Abstract: There are provided a single stage forward-flyback converter, and a power supply apparatus capable of increasing power factor correction and power conversion efficiency. The single stage forward-flyback converter includes: a forward converter unit including a transformer having a primary winding receiving input power and a first secondary winding magnetically coupled to the primary winding to receive power induced thereto, and converting the power in a forward scheme; and a flyback converter unit sharing the transformer, including a second secondary winding, and converting the power in a flyback scheme, wherein the forward converter unit is selectively operated according to a voltage level of the input power.

Abstract: In conventional multi-output switching power supply device, power is supplied from a relatively high voltage side output to a relatively low voltage side output through a dropper circuit which generates relatively large power loss so as to improve the voltage accuracy of a non-stabilized output, so that power supply efficiency is low and heat generated from the dropper circuit is high. One DC power supply of a plurality of DC power supplies on the secondary side is a stabilized output (24 V output terminal TM3) having a voltage stabilizing means for stabilizing the output voltage by feeding back the output voltage to a primary side control circuit 4, and the rest of the DC power supplies are non-stabilized outputs (12 V output terminals TM4) not having a voltage stabilizing means for feeding back the output voltage to the primary side.

Abstract: Switching device controllers, drive circuits, power converters and related methods are disclosed. One example controller for a switching device includes a drive circuit for controlling the switching device and an auxiliary circuit coupled to the drive circuit. The auxiliary circuit includes an input for receiving a waveform having alternating first and second intervals. The auxiliary circuit is configured to energize the drive circuit during the first intervals and de-energize the drive circuit during the second intervals. One example method of energizing and de-energizing a drive circuit for a switching device includes receiving a waveform having alternating first and second intervals, energizing the drive circuit during the first intervals, and de-energizing the drive circuit during the second intervals.

Abstract: A control method for bidirectional DC-DC converter includes: operating a bidirectional DC-DC converter in a boost mode, the bidirectional DC-DC converter including a low voltage side and a high voltage side, the low voltage side including low-voltage-side switches, a voltage clamping switch and a voltage clamping capacitor and the high voltage side including high-voltage-side switches; switching the voltage clamping switch with a predetermined duty cycle prior to switching on all of the low-voltage-side switches; adjusting the duty cycle of the voltage clamping switch being smaller than a turn-off interval of the low-voltage-side switches to reduce the conduction loss of the low-voltage-side switches and the voltage clamping switch; alternatively, operating the DC-DC converter in a buck mode; adjusting and extending the duty cycle of the low-voltage-side switches to overlap a turn-off time of the high-voltage-side switches so as to reduce the conduction loss of the low-voltage-side switches.

Abstract: 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.

Abstract: The invention puts forward a bidirectional DC-DC converter for high voltages that is as simple as possible and that entails as few losses as possible. The bidirectional DC-DC converter (1) converter comprises an input stage (2) to convert a DC input voltage into first AC voltage, a transformer (3) to transform the first AC voltage into a second AC voltage, and an output stage (4) to convert the second AC voltage into a DC output voltage, whereby, in order to provide the first and/or second AC voltage, at least one of the input stages (2) and/or output stages (4) comprises a branch of a multi-level converter (5) with a first number of active first semiconductor switches (61).

Abstract: A system simplification can be achieved by reducing the number of sensors required to detect currents and voltages when an output current is estimated. A switching power supply device 6 includes a current transformer 12, a switching circuit 13, a rectifying circuit 15, a smoothing circuit 16, an input voltage detecting circuit 18, a control part 19, an output voltage detecting circuit 22 and a PWM signal generating part 30. The control part 19 calculates a duty rate and an average value of voltage of the secondary side voltage of the current transformer 12 detected by the input voltage detecting circuit 18 based on a waveform of the detected voltage. The control part 19 calculates an output current lo based on the calculated duty rate, the calculated average value of voltage and an output voltage Vo detected by the output voltage detecting circuit 22.

Abstract: An energy transfer assembly with tuned leakage inductance and common mode noise compensation is disclosed. An example energy transfer assembly for use in a resonant power converter includes a first winding wound around a bobbin mounted on a magnetic core. The first winding has a first number of layers proximate to a first end along a length of the bobbin and a second number of layers proximate to a second end along the length of the bobbin. The energy transfer assembly also includes a second winding wound around the bobbin. The second winding has a third number of layers proximate to the first end along the length of the bobbin and a fourth number of layers proximate to the second end along the length of the bobbin. The first and second windings are wound around the bobbin such that at least a portion of one of the first and second windings overlaps at least a portion of an other one of the first and second windings around the bobbin.

Abstract: A converter is configured with a transformer that has a primary coil and a secondary coil, a first switching element that is serially connected to the primary coil, a control circuit that controls the first switching element, and a firs rectifying element that supplies electric power to the control circuit. A ground potential of the control circuit and the first rectifying element are connected to the primary coil at different points. Accordingly, an inverter is miniaturized and manufacturing costs are reduced.

Abstract: A method for controlling an multi-stage inverter comprises controlling an input converter of the multi-stage inverter with an input controller and controlling an output converter of the multi-stage inverter with an output controller separate from the input controller. The input controller and output controller may be galvanically isolated. Additionally, the method may include communicating data between the input controller and the output controller over a power bus of the multi-stage inverter.

Abstract: The present invention relates to a power converter circuit for operating on a DC input voltage comprising a forward ferrite-core transformer having at least two primary windings and at least one secondary winding, at least one automatic switching device provided between the primary windings, a current sense circuit provided between the first primary winding and the automatic switching device, and a control unit having a voltage sense circuit, the control unit being connected to the automatic switching device and the current sense circuit and being configured to operate the automatic switch on the basis of an input parameter, thereby controlling the out put voltage.

Abstract: An example control element for use in a power supply includes a high-voltage transistor and a control circuit to control switching of the high-voltage transistor. The high-voltage transistor includes a drain region, source region, tap region, drift region, and tap drift region, all of a first conductivity type. The transistor also includes a body region of a second conductivity type. An insulated gate is included in the transistor such that when the insulated gate is biased a channel is formed across the body region to form a conduction path between the source region and the drift region. A voltage at the tap region with respect to the source region is substantially constant and less than a voltage at the drain region with respect to the source region in response to the voltage at the drain region exceeding a pinch off voltage.

Abstract: Provided is a resonant switching power supply device that can reduce a common mode noise as well as an increase in frequency when a load is light. A resonant switching power supply device 1 equipped with a PFM control circuit 10 to control a switching frequency in such a way that an output voltage is brought to a desired value includes: a resonant circuit where a primary winding N1 of a transformer T2, a current resonant capacitor Cri and a reactor Lr are connected in series; rectifying circuits D1, D2 and Co that are connected to secondary windings N2 and N3 of the transformer T2 and obtain the output voltage Vo; and an electrostatic shield plate S1 disposed between the primary winding N1 and secondary windings N2 and N3 of the transformer T2.

Abstract: The present invention relates to an oscillator that is capable of realizing duty balancing. The oscillator determines a switching frequency of a converter converting an input voltage according to a switching operation of switches to generate an output voltage. The oscillator determines a first half cycle of a duty signal determining the switching frequency by using a reference current according to a feedback signal corresponding to the output voltage. The oscillator senses a first half cycle period by using an output of the frequency setting unit, and determines the same period as the first half cycle as a second half cycle of the duty signal after the first half cycle.

Abstract: A power converter includes a current controller coupled to an energy transfer element to selectively enable a first, second or third current in the current controller. The first current is substantially zero, the second current is greater than the third current, and the third current is greater than the first current. The third current only partially discharges a capacitance coupled to the energy transfer element and the current controller. A control circuit is to be coupled to the current controller to selectively enable the first, second or third current in the current controller. A first feedback circuit is coupled to generate a first feedback signal while the first current is enabled by the current controller after a full discharge pulse. A second feedback circuit is coupled to generate a second feedback signal while the first current is enabled in the controller after a partial discharge pulse.

Abstract: DC-to-DC converters are protected from damage by, among other things, monitoring and controlling forward and reverse currents in their transformer primary windings. The currents are discontinued if their values fall outside a predetermined range or if they flow during a portion of the switching cycle in a manner that would result in cross-conduction. Power switches in these converters are also protected from damage by adjusting the maximum duty cycles of these converters to vary with their input voltages. In this way, the maximum voltage across the power switches is kept within a relatively narrow range. These protective features can be combined in any number of ways to fit the application at hand.

Abstract: One embodiment of the invention relates to a power apparatus. The power apparatus includes a power converter configured to convert an input voltage to an output voltage for providing power at an output thereof to which a load is connectable. The converter can include an isolation barrier configured to electrically isolate the output and the load from an input source that provides the input voltage. The system also includes a control loop that includes indirect sense circuitry configured to indirectly derive an indication of at least one of output current and output power of the converter. The control loop is configured to control output current or output power based on the indirectly derived indication of output current or output power, respectively.

Abstract: A power supply unit includes a switching power converter responsive to a control signal to switch a power switch thereof to provide an output voltage and an output current for a load. To reduce light-load or no-load power consumption of the power supply unit, the power supply unit repeats a process of stopping switching the power switch and recovering switching the power switch for a period of time once the output voltage decreases to be lower than a reference voltage.

Abstract: A control circuit for an inverter according to the present invention comprises a PWM circuit and a controller. The PWM circuit generates switching signals in accordance with a PWM control signal. The switching signals are coupled to switch a transformer through transistors for generating an output of the inverter. The controller is coupled to receive a command signal and an input signal for generating the PWM control signal. The input signal is correlated to an input voltage waveform of the inverter. The command signal is utilized to determine a power level of the output of the inverter. The advantages of the control circuit are lower cost, small size, good power factor and higher reliability.

Abstract: In one embodiment, a method of forming a conditioning circuit includes configuring an output biasing network to provide a biasing voltage to an MOS transistor to enable the MOS transistor to operate in a saturated operating mode for input voltages that are less than a threshold voltage.

Abstract: The invention relates to a control device (1) intended to be employed in a switched electrical power supply system, said system being able in particular to be employed in a variable speed drive to power its electronics. The control device (1) comprises a first transistor (T1) intended to receive control signals originating from a control unit (U) and a second transistor (T2) connected in series with the first transistor (T1) and provided with a floating-control gate (G).