Abstract: A voltage up and down synchronization and rectification type DC-DC converter goes up and down an input voltage using an inductor. The voltage up and down synchronization and rectification type DC-DC converter comprises a voltage up and down use rectification circuit including a pair of PMOS and NMOS transistors connected in parallel to each other.

Abstract: Enhancement of the power conversion efficiency and reduction of switching noise of a power supply circuit are achieved. The power supply circuit includes, on the primary side, a composite resonance type converter formed from a current resonance type converter and a partial voltage resonance circuit in combination, and is configured so as to produce a plurality of secondary side DC output voltages. A particular one of the plural secondary side DC output voltages is controlled to a constant voltage by variably controlling the switching frequency of a primary side switching converter. Each of the remaining secondary side DC output voltages is controlled to a constant voltage by adjusting the level of control current to be supplied to a controlling winding of a control transformer in response to the level of the secondary side DC output voltage to adjust the inductance of a controlling winding of the control transformer inserted in a rectification current path.

Abstract: Provided is a current-source push-pull DC-DC converter using an active clamp circuit for reusing energy of leakage inductances by not only diodes on a secondary side of a transformer being zero-current switched using a series-resonant full-wave rectifier, but also the active clamp circuit on a primary side of the transformer, which provides a discharge path of the energy stored in the leakage inductances, increases power conversion efficiency even for a wide input voltage range and reduces a switch voltage stress as compared to a conventional current-source push-pull circuit by operating even for a duty ratio below 0.5 by flowing a current of an input inductor through capacitors of the active clamp circuit when both main switches are off.

Abstract: A current sensing circuit for use in a switching regulator having a high-side switch. The current sensing circuit includes a first sensing circuit coupled to the high-side switch for measuring current flowing in a positive direction through the high-side switch. The first sensing circuit includes a first replica device for generating a current which is a scaled version of the positive current flowing through the high-side switch. The current sensing circuit further includes a second sensing circuit coupled to the high-side switch for measuring current flowing in a negative direction through the high-side switch. The second sensing circuit includes a second replica device for generating a current which is a scaled version of the negative current flowing through the high-side switch.

Abstract: A method of regulating an output voltage by utilizing a switching regulator, where the switching regulator includes a high side switch, a low side switch having an active diode, a controller coupled to the high side switch and the low side switch, and a current measuring circuit coupled to the high side switch.

Abstract: A circuit with a magnetically variable transformer having primary and secondary windings wound on a magnetic core wherein the transformer core with associated windings is placed in close proximity to an independently wound control coil. The transformer core is placed within the bore of the control coil and an optional focusing armature concentrates the magnetic field at the poles. Application of a control current forms poles at the control coil extremities and causes a change in permeability of the transformer core thereby altering the power output of the transformer inversely to the magnitude of the control current. The control current from the output of the secondary coil of a current transformer in series with the load and conditioned by a feedback conditioning circuit modulates the level of the control current. The magnetically variable transformer controls a D.C. to A.C. inverter circuit, which is useful in supplying power to a fluorescent lamp and other A.C. receptive loads.

Abstract: In a non-isolated DC/DC converter, a reference potential for a low-side pre-driver which drives a gate of a low-side MOSFET is applied from a portion except for a main circuit passing through a high-side MOSFET and the low-side MOSFET so that a parasitic inductance between a source of the low-side MOSFET and the pre-driver is increased without increasing the sum of parasitic inductances in the main circuit and negative potential driving of the gate of the low-side MOSFET can be performed and a self turn-on phenomenon can be prevented without adding any member and changing drive system.

Abstract: A single sleep mode controller which ensures that there is at least a corresponding minimum voltage level across capacitors when the corresponding regulators are turned off. In an embodiment, the sleep mode controller uses a single comparator which compares the voltages across capacitors in a time division multiplexed (TDM) manner, and initiates the charging operation for the capacitor if the voltage level falls below a corresponding minimum voltage level. The sleep mode controller continues the charging operation until the voltage level exceeds a corresponding upper threshold value. Due to the use of the single controller, power and/or space savings may be attained.

Abstract: A power conversion apparatus, such as a UPS, includes a first waveform reference signal generator circuit operative to generate a first waveform reference signal responsive to an AC bus, and a second waveform reference signal generator circuit operative to generate a second waveform reference signal, e.g., a more consistently sinusoidal signal produced by another source. The apparatus further includes a control circuit that selectively generates a third waveform reference signal from the first and second waveform reference signals, and a power converter circuit (e.g., a rectifier and/or inverter) coupled to the AC bus and operative to transfer power to and/or from the AC bus responsive to the third waveform reference signal. In particular, the control circuit may be operative to weightedly combine the first and second waveform reference signals to generate the third waveform reference signal.

Abstract: A multiphase DC-to-DC power converter has two or more sets of input switches, each set of input switches driving primary windings of an associated transformer. Each transformer has one or two secondary windings, the secondary windings feeding power through output switches or rectifiers through an associated output inductor into a common filter. At least two of the output inductors are magnetically coupled.

Abstract: A wide-range compatible voltage resonant converter provides high efficiency and allows use of low-breakdown-voltage products for a circuit. The voltage resonant converter is provided with a secondary-side parallel resonant circuit and a secondary-side series resonant circuit, and a loose coupling state is established in which the coupling coefficient of an isolation converter transformer is about 0.7 or less. Thus, a constant-voltage control characteristic is obtained as a sharp unimodal characteristic, which narrows the switching frequency control region required for stabilization of an output voltage. In addition, a primary-side parallel resonant frequency, a secondary-side parallel resonant frequency and a secondary-side series resonant frequency are set so that a favorable power conversion efficiency is obtained. Moreover, an active clamp circuit is provided to suppress the peak level of a resonant voltage pulse to thereby allow use of low-breakdown-voltage products for a switching element and so on.

Abstract: A DC converter alternately turns on and off a main switch Q1 connected in series with a primary winding P1 of a transformer T and a sub-switch Q2 contained in a series circuit connected to each end of the primary winding P1 of the transformer T or to each end of the main switch Q1, rectifies and smoothes a voltage of a secondary winding S1 of the transformer T, and provides a DC output. The DC converter includes a time difference detection circuit 13 to detect an interval between when the main switch Q1 reaches a minimum voltage after the sub-switch Q2 is turned off and when the main switch Q1 is turned on and a first delay circuit 14 to delay the ON timing of the main switch Q1 according to an output from the time difference detection circuit 13 so that the main switch Q1 is turned on at around the minimum voltage.

Abstract: A low power, high voltage power supply system includes a high voltage power supply stage and a preregulator for programming the power supply stage so as to produce an output voltage which is a predetermined fraction of a desired voltage level. The power supply stage includes a high voltage, voltage doubler stage connected to receive the output voltage from the preregulator and for, when activated, providing amplification of the output voltage to the desired voltage level. A first feedback loop is connected between the output of the preregulator and an input of the preregulator while a second feedback loop is connected between the output of the power supply stage and the input of the preregulator.

Abstract: A switching power supply circuit includes a primary side series resonant circuit forming a current resonant converter, and a secondary side series resonant circuit formed by at least a secondary winding and a secondary side series resonant capacitor, whereby a coupling type resonant circuit is formed by magnetic coupling of an isolated converter transformer. In order to obtain a unimodal characteristic for this coupling type resonant circuit, the total coupling coefficient of the isolated converter transformer is set to 0.65 or lower. For power factor improvement, a power factor improving circuit of a power regeneration system or a voltage feedback system is provided.

Abstract: A switching power supply circuit in which, in order to both provide high power conversion efficiency of a complex resonant converter having a synchronous rectifier circuit and reduce a circuit scale and cost by simplifying the circuit, a synchronous rectifier circuit of a winding voltage detection system is provided on a secondary side of the complex resonant converter, a coupling coefficient is decreased to about 0.8 by setting a gap length in an isolated converter transformer to about 1.5 mm, and numbers of turns of a primary winding and secondary windings are set such that a level of a voltage induced per turn (T) of the secondary windings is 2 V/T. Thus, since magnetic flux density at a core of the isolated converter transformer is decreased to a certain value or lower, a secondary side rectified current can be in a continuous mode even under a condition of heavy load.

Abstract: In one aspect, the present invention includes a power adjustment apparatus. The apparatus includes a local controller and one or more sensors distributed within a power grid. The sensors are configured to assess conditions including power consumption and delivered voltage level and are configured to transmit data representative of the assessed conditions to the local controller. The apparatus also includes a device associated with the one or more sensors, configured to adjust an output power level in response to commands from the local controller. The device is deployed at an associated location within the power grid. The device is configured to increase an associated output electrical parameter when the local controller determines that such will reduce power consumption.

Abstract: An input stage circuit of a three-level DC/DC converter is provided. The input stage circuit uses metal-oxide-semiconductor field effect transistors (MOSFETs) to discharge a flying capacitor to maintain the voltage across the flying capacitor at a half of the input voltage. Not only can the input stage circuit solve the high voltage issue across the flying capacitor in the prior art, but the circuit is able to operate normally without increasing power consumption during discharging, thereby avoiding problems of the prior art.

Abstract: A multi-stage, push-pull driven, resonant DC-AC converter ties the center-taps of primary windings of respective push-pull stages together, and drives each center-tap with a current source. Tying the center-taps of the primary windings of the respective DC-AC converters' transformers together forces the voltages at these locations to be the same, so as to achieve mutual resonant synchronization between the two stages. Connecting the center-taps to a current source provides the necessary power for each stage and allows for a variation in current between stages, as the center-tap voltages track one another. The tied-together center-tap voltage is monitored to obtain the zero voltage switching required for efficient operation of switching devices of each DC-AC converter stage.

Abstract: A current/voltage converter arrangement is proposed, in which a first switch device (T1) with a first diode (TD1) is provided between a first input terminal (TE1) of a primary side (TP) of a transformer device (T) provided and a first input terminal (E1) of an input region (E), in which a second switch device (T2) with a diode (TD2) is provided between a second input terminal (TE2) of the primary side (TP) and a second input terminal (E2) of the input region (E).

Abstract: An electrical power converter receives input power of one type or level at input terminals and supplies output power of another type or level at output terminals. The power converter includes a high frequency transformer, an input circuit connected between the input terminals and the primary of the transformer, and an output circuit connected between the secondary of the transformer and the output terminals, a controller for controlling pulse width of current pulses produced by the input circuit, and a current limiting circuit. The current limiting circuit allows very high surge currents immediately upon demand without waiting for a voltage drop feedback circuit, then dynamically reduces the current limit over time based on the averaged current in the input circuit.

Abstract: A power converter circuit has an inductor input and switching means to put a pair of capacitors alternately in series or in parallel. By pulse width modulating between the states, the voltage on the capacitors can be controlled over a two to one variation of the input voltage. A pair of transformer isolated power converter sub-circuits can be connected to the capacitors, and their outputs can be combined to provide a single controlled output voltage.

Abstract: A push/pull-type control signal generating circuit outputs two control signals to control directly and drive switching actions of two electronic switches of a push/pull-type circuit architecture. The push/pull-type control signal generating circuit has a first AND-gate logic unit, a second AND-gate logic unit, a circuit protection unit, a function generator, a clock generator, a soft boot unit connected to the clock generator, a sample and hold unit, a first comparator connected to the soft boot unit and the function generator, an OR-gate logic unit connected to the soft boot unit, the first comparator and the first and second AND-gate logic units, a second comparator connected to the sample and hold unit, the function generator and the first and second AND-gate logic units, and a dead time control unit connected to the function generator and the first and second AND-gate logic units.

Abstract: A switching power supply unit of the present invention a timing generating circuit (121) which receives a first control signal formed by a rectifier-transistor driving circuit (104), forms a second control signal based on the first control signal, and supplies the second control signal to a control electrode of the rectifier transistor (113). The first control signal is synchronized with the switching operation of a half-bridge circuit (102), and the second control signal exceeds a threshold voltage of a rectifier transistor (113) at a timing substantially equal to the timing that one edge of the first control signal is generated and falls below the threshold voltage of the rectifier transistor (113) at a timing earlier by predetermined time than the timing that the other edge of the first control signal is generated.

Abstract: The voltage applied to a first grid electrode 71 of an X-ray tube 11 by a grid voltage control section 110 is controlled with reference to a predetermined negative voltage from a negative voltage generating section 112 when an object 5 to be inspected does not exist in an imaging area (irradiation area of an X-ray from an X-ray source 1) so that the pulse outputted from a pulse generator 105 is in its OFF state, and is controlled with reference to a reference positive voltage from a reference voltage generating section 115 when the object 5 to be inspected exists in the imaging area in the X-ray image intensifier 2 (irradiation area of the X-ray from the X-ray source 1) so that the pulse outputted from the pulse generator 105 is in its ON state, whereby both of the cutoff voltage and grid operating voltage are applied in a stable state.

Abstract: An electric power conversion device comprises switching elements 2a, 2b making up a push-pull converter, a pulse transformer T, a rectification diode D1, a rectification diode D2, a choke coil L, a smoothing capacitor C, a DC magnetic deviation prevention means 3, and an inverter 4. The DC magnetic deviation prevention means 3 detects the coil currents I1, I2 flowing in the primary windings M1, M2 of the pulse transformer T. By controlling (shortening) the on time of the switching element having a greater amount of current, the coil currents I1, I2 are balanced (I1=I2), thereby preventing the magnetic deviation phenomena of the pulse transformer T.

Abstract: A CCFL power converter circuit is provided using a high-efficiency zero-voltage-switching technique that eliminates switching losses associated with the power MOSFETs. An optimal sweeping-frequency technique is used in the CCFL ignition by accounting for the parasitic capacitance in the resonant tank circuit. Additionally, the circuit is self-learning and is adapted to determine the optimum operating frequency for the circuit with a given load. An over-voltage protection circuit can also be provided to ensure that the circuit components are protected in the case of open-lamp condition.

Abstract: An apparatus and method for high frequency alternating power generation to control kilowatts of supplied power in microseconds. The present invention includes a means for energy storage, push-pull switching means, control electronics, transformer means, resonant circuitry and means for excess energy recovery, all in electrical communication. A push-pull circuit works synchronously with a force commutated free-wheel transistor to provide current pulses to a transformer. A change in the conduction angle of the push-pull circuit changes the amount of energy coupled into the transformer's secondary oscillating circuit, thereby altering the induced secondary resonating voltage. At the end of each pulse, the force commutated free-wheel transistor causes residual excess energy in the primary circuit to be transmitted back to the storage capacitor for later use.

Abstract: A high-voltage power supply (10) includes: a power scaling section (130) that receives an input voltage signal and converts the input voltage signal to a controllable DC voltage; a push-pull converter (140) for converting the controllable DC voltage to a high-frequency wave; and a voltage multiplier (200) receiving the high-frequency wave generated by the push-pull converter (140) and performing successive voltage doubling operations to generate a high-voltage DC output. In one implementation, the voltage multiplier (200) receives a square wave having a frequency of approximately 100 kHz and outputs an adjustable DC voltage of approximately 0-to-30 kV. In one implementation, the high-voltage power supply (10) includes an insulation system (250) for the voltage multiplier module (200), such an insulation system being formed of n insulating layers and m conducting strips positioned between successive insulating layers.

Abstract: A multiple-phase power converter comprises a non-isolated, double-ended transformer having a plurality of windings, a high-side switch portion, a low-side switch portion, an output portion, and a controller. The high-side switch portion includes a first power switch connecting an input voltage source (VIN) to a virtual phase node through a first winding of the plurality of windings and a second power switch connecting the input voltage source to the virtual phase node through a second winding of the plurality of windings. The first and second windings are arranged with opposite polarity. The low-side switch portion includes a third power switch connecting the virtual phase node to ground through a third winding of the plurality of windings and a fourth power switch connecting the virtual phase node to ground through a fourth winding of the plurality of windings. The third and fourth windings are arranged with opposite polarity.

Abstract: A modified push-pull booster circuit is proposed, wherein two alternately switching transistors are disposed on the primary winding of a transformer, and a bridge rectifier and a charging circuit are disposed on the secondary winding; wherein the bridge rectifier has a pair of inductors with inductive coupling installed on the first half and second half of the circuit. The push-pull circuit uses series inductance to step up the bus voltage, and, because of the degaussing effect when current is induced on the inductors, the inductance of the inductor can be decreased even without using snubber circuit, thus decreasing the peak voltage of the bridge rectifier, and balancing the magnitude of current flow in the secondary winding. By reducing the turn ratio on the transformer windings, the operating efficiency of the booster circuit can be considerably improved.

Abstract: The present invention relates to a method and an apparatus for controlling an electric motor by regulating at least the current Iout, the voltage Uout and the frequency fout to an input of said motor, where the number of revolutions of said electric motor is proportional to said frequency fout. If an available power Pin from an energy source is greater than or equal to the nominal requested power Pnom of said electric motor, the current Iout, voltage Uout and frequency fout are set to there corresponding nominal values Inom, Unom and fnom, respectively, to achieve said requested power Pnom and frequency fnom. If said available power Pin is less than the requester power Pnom, the voltage Uout and the frequency fout are reduced such that the relation between the voltage Uout and the frequency fout is essentially constant while said current Iout is kept at its nominal value Inom.

Abstract: A switching power supply includes a transformer having a primary winding connected to a pair of a.c. input terminals via a rectifier circuit, and a secondary winding connected to a pair of d.c. output terminals via a rectifying and smoothing circuit. Connected between the pair of outputs of the rectifier circuit via an inductor, reverse-blocking diode, and part or whole of the transformer primary, a primary switch is turned on and off at a repetition frequency higher than the frequency of the a.c. input voltage. A soft-switching circuit is provided which comprises a serial connection of a transformer tertiary, an ancillary diode and an ancillary switch. This serial circuit is connected in parallel with the serial connection of the transformer primary and primary switch for zero-voltage switching of the primary switch.

Abstract: A circuit that provides the root-mean-square (RMS) value of an input signal and that detects and independently recovers from an output fault condition is provided. The circuit includes reconfigurable circuitry that changes from normal operating mode to fault recovery mode when an output fault is detected. During fault recovery mode, the circuit provides a modified output signal that allows independent recovery from an output fault condition. Once recovery is complete, the circuit returns to normal operating mode and provides a DC output signal proportional to the RMS value of an AC input signal.

Abstract: A constant voltage reset circuit used in a forward converter for the holdup time requirement or the wide input voltage range is disclosed. In one embodiment, the constant voltage reset circuit comprises a reset capacitor, a parallel-coupled switch, and a diode coupled in series with the reset capacitor which is configured to cooperate therewith to reset an energy from the transformer. The forward converter employing the reset circuit or the method achieves a higher efficiency with a larger turn ratio and without the 50% limitation of maximum duty cycle.

Abstract: A power inverter includes a transformer having a primary winding with a first and second ends and a tap between the first and second ends for receiving a DC voltage input, and a secondary winding for outputting an output waveform. A comparator compares the output waveform to a reference signal and outputs a correction signal based on the comparison. A controller receives the correction signal and provide a switching signal. The duty cycle of the switching signal is adjusted based on the correction signal. First and second switches are coupled to the first and second ends, respectively, of the primary winding. The first and second switches switch the transformer in accordance with the switching signal so that the output waveform tracks the reference signal.

Abstract: Disclosed is about a single stage converter in an LCD backlight inverter which is embodied into an integrated circuit and has an individual circuit structure for converting DC current into AC current. The single stage converter in the LCD backlight inverter of the invention is embodied as an ASIC to realize an individual application circuit, replaces conventional two-stage articles to reduce the size, enhances the efficiency and reduces the part number thereby saving the cost for materials.

Abstract: A multi-stage DC-DC converter is provided that utilizes multiple loops in the control system to perform stable operation. The multi-stage DC-DC converter includes: a first DC-DC converter, a second DC-DC converter provided as a latter stage to said first DC-DC converter and a control circuit that controls the switching operation performed by said first DC-DC converter based on at least the output voltage of said first DC-DC converter and the output voltage of said second DC-DC converter.

Abstract: A high input-voltage push-pull forward voltage regulator module (VRM) has high efficiency and fast transient response. The VRM has a primary side wherein two switches and two primary transformer windings are alternately connected in a loop. A capacitor is connected between any of two interleaved terminations. The remaining two terminations are connected to input and ground respectively. The two primary transformer windings have the same number of turns. A number of secondary sides may be used such as, for example, a half wave rectifier or a center tapped secondary. The high input-voltage push-pull forward VRM has high efficiency and fast transient-response with reduced filter capacitance and inductance. Its magnetic components can be easily integrated. As a result, very high power density can be achieved. The device die size needed to achieve the required efficiency is reduced. And control is simple. Therefore, this topology is very cost effective.

Abstract: A constant voltage reset circuit used in a forward converter for holdup time requirement or wide input voltage range is disclosed. In one embodiment, the constant voltage reset circuit comprises (1) a reset capacitor, and (2) a parallel-coupled switch and a diode coupled in series with the reset capacitor which is configured to cooperate therewith to reset an energy from the transformer. The forward converter employing the reset circuit or the method achieves high efficiency with large turn ratio and without 50% limitation of maximum duty cycle.

Abstract: A switching power supply suitable for driving a load whose load current may fluctuate abruptly comprises a main circuit unit including a switching circuit for converting a DC input voltage to an AC voltage and an output circuit for rectifying the AC voltage to produce a DC output voltage, and a control circuit for controlling the operation of the main circuit unit, the transfer function of the control circuit assuming a first value when the load current supplied by the main circuit unit changes at a rate not exceeding a prescribed rate and assuming a second value exceeding the first value when the load current changes at a rate exceeding the prescribed rate. The switching power supply therefore exhibits markedly improved transient response when the load current changes at a rate exceeding the prescribed rate because the transfer function of the control circuit is increased relative to that under normal condition.

Abstract: The invention relates to a power supply for an illumination system used to expose photo-initiated adhesives. The illumination system includes an arc lamp to provide light. As the lamp ages, its electrodes deteriorate, reducing the amount of light directed into a light guide and ultimately onto the adhesive. The power supply provides an increasing power input to the lamp to increase the light output of the lamp, countering this deterioration at least in part. The voltage and current drawn by the lamp are measured and a skewed control signal which magnifies the level is used to control the power input to the lamp.

Abstract: A DC-DC converter for converting DC power received from a high-voltage DC power supply to a well-regulated output voltage that is significantly lower than the received voltage. The converter includes a regulated voltage-reduction stage which receives high-voltage DC electrical power and supplies DC electrical power at a voltage which is lower than that received. The converter also includes a separately regulated electrically isolated stage, energized by electrical power received from the voltage-reduction stage, that supplies DC electrical power to a load at the significantly lower output voltage. A feedback circuit couples an output signal from the output of the isolation-stage for regulating operation of the voltage-reduction stage and of the isolation stage.

Abstract: A switching power supply unit includes first and second switching circuits which alternately turn first and second switching elements on and off with an intermediate period in which both are turned off, and energy is stored in a primary winding of a transformer during an ON period of the first switching element and the energy is discharged from a secondary winding of the transformer during an OFF period of the first switching element. A control circuit includes an OFF period extending circuit connected to a control terminal of the first switching element, such that a transistor remains turned on for a desired period even after the energy has been discharged from the secondary winding, extending the OFF period of the first switching element for the desired period. In a light load operation, a phototransistor in the second control circuit is turned on so that the ON period of the second switching element will be shorter than the time required to discharge the energy from the secondary winding.

Abstract: A multiphase zero-volt switching, zero volt switch resonant DC-DC regulator includes: a zero-volt switch zero volt switch; a DC output voltage means; a variable resonant circuit; a synchronous rectifier; and a sensing circuit. The sensing circuit senses a DC output voltage at the DC output of the regulator. The regulator uses the resonant circuit in conjunction with the sensing circuit to provide a substantially constant DC output voltage at a fixed frequency. If the sensing circuit senses a change in the DC output voltage, then a resonant frequency of the regulator is changed by the variable resonant circuit. This allows the oscillator of the regulator to maintain a fixed frequency, thus ensuring the availability of zero-volt switching over the full range of operation. The regulator also has the advantages of low power loss, reduced ripple, and a very fast transient response time.

Abstract: A resonant reset dual switch forward converter is disclosed. The resonant reset dual switch forward converter includes an input for accepting a DC voltage; a transformer having a primary winding and a secondary winding; a first and a second switch connected in series with the primary winding of the transformer for periodically connecting the input to the primary winding; a resonant capacitor for resetting the transformer during the OFF time of the first and second switches; and an auxiliary switch remaining OFF during the ON time of the first and second switches, and connecting the primary winding to the resonant capacitor during the OFF time of the first and second switches. The resonant reset dual switch forward converter provides a switching duty cycle greater than 50%, obtains a zero-voltage-switching condition for the first and second switches, and maintains the voltage stress of the f first and second switches around the input voltage.

Abstract: A power supply (10) has a first transistor (20) coupled for switching a coil current (I19) in response to a first control signal (VC1). A second transistor (30) has a body diode (32) for discharging the coil current to produce a power factor corrected signal (VPFC) . A conduction channel (31) of the second transistor is responsive to a second control signal (VC3) for developing a second coil current (I61) from the power factor corrected signal to adjust an output signal of the power supply, where the second control signal commences a time interval (TD2) after the first control signal terminates.

Abstract: The present invention provides a power converter and a method for converting power. The power converter comprises an inductor, a transformer, first and second switches, a diode, and a full bridge. The inductor comprises a first winding, a second winding, and a third winding, and is coupled to an input voltage. The transformer has a first primary winding coupled to the first winding of the inductor, a second primary winding coupled to the second winding of the inductor, and a third primary winding coupled to the third winding of the inductor. The first switch is coupled to the first primary winding of the transformer, and the second switch is coupled to the second primary winding of the transformer. The diode is coupled to the third primary winding of the transformer. The full bridge is coupled to a secondary winding of the transformer, and the output voltage emanates therefrom.

Abstract: A power supply (10) has a first transistor (20) coupled for switching a coil current (Il9) in response to a first control signal (VC1). A second transistor (30) has a body diode (32) for discharging the coil current to produce a power factor corrected signal (VPFC). A conduction channel (31) of the second transistor is responsive to a second control signal (VC3) for developing a second coil current (I61) from the power factor corrected signal to adjust an output signal of the power supply, where the second control signal commences a time interval (TD2) after the first control signal terminates.

Abstract: In an isolation type DC-DC converter for performing full-wave rectification in the secondary of a transformer, two switching sections 11 and 13 alternately switch ON and OFF, thereby reversing the current I3 flowing through a primary winding 3a of the transformer 3. A switching control circuit 7 outputs switching signals G1 and G3 to the switching sections 11 and 13, respectively, thereby controlling the switching of the switching sections. A load current sensing section 9 senses the amount of load current, then compares it with a predetermined threshold value. When the amount of load current sensed is smaller than the threshold value, a delay circuit 8 delays the switching signals G1 and G3 to the switching sections 11 and 13 for a predetermined delay time. The delay time is set to be substantially equal to ¼ of the resonance period determined by the self-inductance of the primary winding 3a of the transformer 3.

Abstract: A DC-DC converter for converting DC power received from a high-voltage DC power supply to a well-regulated output voltage that is significantly lower than the received voltage. The converter includes a regulated voltage-reduction stage which receives high-voltage DC electrical power and supplies DC electrical power at a voltage which is lower than that received. The converter also includes a separately regulated electrically isolated stage, energized by electrical power received from the voltage-reduction stage, that supplies DC electrical power to a load at the significantly lower output voltage. A feedback circuit couples an output signal from the output of the isolation-stage for regulating operation of the voltage-reduction stage and of the isolation stage.