Abstract: A transformer includes a first secondary winding, a second secondary winding, and a third secondary winding. The second secondary winding and the third secondary winding are wound to include the same number of turns and to have opposite magnetic polarities. A low-pass filter includes a second inductor defined by a leakage inductance of the second secondary winding connected in series with the second secondary winding, a second inductor defined by a leakage inductance of the third secondary winding connected in series with the third secondary winding, and a second capacitor. An output voltage is output from an output terminal of the low-pass filter.

Abstract: A voltage detecting circuit to perform voltage detection by introducing a voltage from a detection node, comprises: a first resistance, a second resistance, and a first switching element, connected in series with each other from the detection node to reference electric potential in order; and a detection circuit for performing a detection operation of a voltage by receiving input of the voltage from a node between the first resistance and the second resistance, wherein a control voltage generated on the basis of the voltage at the detection node is supplied to a control terminal of the first switching element, and the first switching element is turned on when the voltage at the detection node is large, and the first switching element is turned off when the voltage at the detection node is small.

Abstract: A semiconductor device of a three-level inverter circuit with a reduced number of power supplies for driving IGBTs. The semiconductor device includes a series-connected circuit of IGBTs between P and N of a DC power supply and an AC switch element that is connected between a series connection point of the series-connected circuit and a neutral point of the DC power supply. The series-connected circuit and the AC switch element are integrated into one module. The AC switch element is formed by connecting a collector of a first IGBT to which a diode is connected in reverse parallel and a collector of a second IGBT to which a diode is connected in reverse parallel, and an intermediate terminal is provided at a connection point between the collectors.

Abstract: The disclosed embodiments relate to apparatus and method for reducing power losses in a power supply. There is provided an apparatus comprising means for coupling a first signal (S2) to a reference level (ground) when the coupling means is conductive, means for placing the coupling means in a conductive state during a duration of a portion of a period of a second signal (S3), and means for altering the duration of conduction of the coupling means in response to an amplitude of the second signal.

Abstract: Disclosed is a PWM rectifier in which switching losses in a semiconductor device are reduced without degrading the response of a control system. In a PWM overmodulation region, the modulation scheme is set to a three-phase modulation scheme. In other regions, a switchover condition such as the amplitude of an input current is acquired and compared with a switchover level. If the switchover condition equals or exceeds the switchover level, the modulation scheme is switched over to a modified two-phase modulation scheme which reduces the number of switching operations to two thirds for the same PWM frequency.

Abstract: In a rectifier circuit, by using a transistor whose off-state current is small as a so-called diode-connected MOS transistor included in the rectifier circuit, breakdown which is caused when a reverse bias is applied is prevented. Thus, an object is to provide a rectifier circuit whose reliability is increased and rectification efficiency is improved. A gate and a drain of a transistor are both connected to a terminal of the rectifier circuit to which an AC signal is input. In the transistor, an oxide semiconductor is used for a channel formation region and the off-state current at room temperature is less than or equal to 10?20 A/?m, which is equal to 10 zA/?m (z: zepto), when the source-drain voltage is 3.1 V.

Abstract: This invention provides a means and method for preventing unwanted semiconductor turn-on and turn-off, caused by a high rate of voltage change, without significantly affecting the desired ON and OFF transitions of the semiconductor. According to this invention, time is provided during either or both bistable ON and OFF semiconductor states, during which the semiconductor gate is allowed to float, neither being driven ON or OFF, and circuitry for lowering gate-node impedance at non-transitional times to prevent state disruptions by dV/dT is provided.

Abstract: Systems, methods, and devices that employ self-driven gate-drive circuitry to facilitate controlling power switches to emulate a diode bridge to synchronously rectify a power signal are presented. A single-phase or multi-phase synchronous rectifier can comprise at least a first pair of switches of a first conducting path and a second pair of switches of a second conducting path that can form or emulate a diode bridge. To facilitate emulating turn-on and turn-off conditions of a diode, a switch can be turned on when voltage across the switch is forward-biased and turned off when switch current is reversed; also, there can be at least one current-controlled switch in each conducting path. Self-driven gate-drive circuitry employs low power components that can facilitate controlling respective switching of the at least first pair and second pair of switches, wherein switching of the switches is also controlled at start-up to emulate a diode bridge.

Abstract: An electronic device having at least a loop-shaped electric conductor generating electric power by electromagnetic induction is provided. The electronic device includes a voltage-detecting unit, a voltage-comparing unit and a separating unit. The voltage-detecting unit is configured to detect a voltage generated in the electric conductor by the electromagnetic induction. The voltage-comparing unit is configured to make a comparison between the voltage detected by the voltage-detecting unit and a predetermined reference voltage and determining whether the voltage detected by the voltage-detecting unit exceeds the predetermined reference voltage. The separating unit is configured to break an electric connection between the electronic conductor and an electronic circuit connecting to the electric conductor when the voltage-comparing unit determines that the voltage detected by the voltage-detecting unit exceeds the predetermined reference voltage.

Abstract: A semiconductor apparatus includes: a first transistor; a second transistor having a higher withstand voltage than the first transistor, a source of the second transistor coupled to a drain of the first transistor, a gate of the second transistor coupled to a source of the first transistor; a third transistor having a higher withstand voltage than the first transistor and a drain of the third transistor coupled to a drain of the second transistor; and a comparator that compares a source voltage of the first transistor with a source voltage of the third transistor, and controls a gate voltage of the first transistor.

Abstract: A system for managing AC energy harvested from a harvesting device (1) including a coil (4) including switching circuitry (S1-S4) coupled between first (7A) and second (7B) terminals of the coil. The switching circuitry includes first (S1), second (S2), third (S1), and fourth (S4) switches. A switch controller (17) closes the second and fourth switches to allow build-up of current (ILh) in the coil, opens one of the second and fourth switches, and closes a corresponding one of the third and first switches in response to the built-up inductor current reaching a predetermined threshold value (Ihrv) to steer the built-up inductor current through the corresponding one of the third and first switches to a current-receiving device (24 and/or RL,CL).

Abstract: The present technology discloses a package for a synchronous rectifier module, and also discloses synchronous rectification circuits and power supply adapters. The synchronous rectification circuit co-packages the synchronous rectifier and the driver into one single package. The single package simplifies the external circuitry and reduces potential electromagnetic interferences.

Abstract: A regulated power supply apparatus and method are provided. The apparatus includes a converter circuit for generating a regulated voltage signal. The converter circuit includes a first switching circuit and a second switching circuit both coupled with an output circuit. A first and a second transformer include a first and a second secondary, which are coupled with each other in series or alternatively, coupled with each other in parallel. An input rectifier circuit is coupled with the first and the second switching circuit. The input rectifier circuit is configured for receiving an AC input voltage and for generating a rectified voltage. The input rectifier circuit includes controlled switches and a first and second configuration of a bridge rectifier that couples the first and second switching circuits in series or parallel depending if the AC input power signal is “high-line” or “low-line.” A controller circuit is provided for enabling either the first configuration or the second configuration.

Abstract: A freewheeling MOSFET is connected in parallel with the inductor in a switched DC/DC converter. When the freewheeling MOSFET is turned on during the switching operation of the converter, while the low-side and energy transfer MOSFETs are turned off, the inductor current circulates or “freewheels” through the freewheeling MOSFET. The frequency of the converter is thereby made independent of the lengths of the magnetizing and energy transfer stages, allowing far greater flexibility in operating and converter and overcoming numerous problems associated with conventional DC/DC converters. For example, the converter may operate in either step-up or step-down mode and may even transition for one mode to the other as the values of the input voltage and desired output voltage vary.

Abstract: Resonant transformer systems and methods of use are described. One aspect may include a primary winding, a secondary winding, and at least one output winding. In further aspects, a transformer may be coupled to the secondary winding. In one aspect, the output winding is coupled to rectifying circuitry, which may be coupled to one or more capacitors.

Abstract: Method for detecting and/or monitoring the temperatures of at least two electronic power switches, in particular semi-conductor power switches that are coupled with or arranged on a common cooling body, whereby a temperature detection and/or monitoring is carried out by means of a temperature model each allocated to a switch, in which switch and operating parameters as well as temperature measurement values are processed for calculating the temperature and/or a temperature difference in the relevant switch, whereby a temperature measurement value from a temperature sensor is used as an input parameter for the temperature model, the same being centrally positioned between at least two switches and standing in a heat conducting connection with the cooling body.

Abstract: A synchronous rectifier circuit rectifies an AC input voltage to produce a DC output voltage. The synchronous rectifier circuit comprises MOSFET switches coupled within the secondary transformer windings resulting in a shortened AC current path compared to conventional synchronous rectifier circuits. The shortened current path mitigates skin and proximity effects, substantially improving the power efficiency of the synchronous rectifier circuit. A rectifier assembly integrates one or more synchronous rectifier circuit within a magnetic core.

Abstract: A multi-output buck converting apparatus with a controllable energy-releasing function includes a main buck converter and at least one auxiliary buck converter to provide multi-output voltages. The multi-output buck converting apparatus further includes an energy releasing unit and an abnormal voltage signal generating unit. The abnormal voltage signal generating unit generates a control signal to control a switch device of the energy releasing unit when the multi-output buck converting apparatus shuts down. Therefore, the energy, which is stored in the auxiliary buck converter, can be released through the energy releasing unit so as to avoid returning the energy to the main buck converter and rebounding a main output voltage.

Abstract: A multi-output buck converting apparatus with a shutdown protection includes a main buck converter and at least one auxiliary buck converter to provide multi-output voltages. The multi-output buck converting apparatus further includes an abnormal voltage signal generating unit. The abnormal voltage signal generating unit generates a control signal to control switch devices of the auxiliary buck converter when the multi-output buck converting apparatus shuts down. Therefore, the stored energy in the auxiliary buck converter can be released through internal loops or external loops with connected operational loads so as to avoid the recovering energy rebounding a main output voltage of the main buck converter.

Abstract: A circuit is provided that includes a parasitic power circuit that powers a parasitic circuit. The parasitic power circuit derives a supply voltage from an external AC or other signal suitable for use as a communications signal. A PMOS transistor or transistors is utilized to enable a supply voltage capacitor to charge substantially to the same voltage as the channel voltage of the communications signal.

Abstract: An n-phase transistor active bridge circuit (BC) connectable between at least two input lines (103, 105, 1051, 1053, 1055) and a pair of output lines (134, 136, 1057, 1059). The BC comprises a plurality of field-effect transistors (FETs) of the same channel type. The FETs (102, 104, 106, 108, 1010, 1012, 1014, 1016, 1018, 1020) are connected to convert an n-phase AC waveform (402, 1102, 1104, 1006) to a DC waveform (502, 1302). The n-phase AC waveform is applied to BC by a voltage source (101, 1002, 1004, 1006) coupled to the input lines. Gate drive circuits (170, 172, 174, 176, 1001a, 1001b, 1001c, 1003a, 1003b, 1003c) supply a voltage to gates (139, 143, 147, 151, 1024, 1034, 1044, 1054, 1064, 1074) of the FETs for switching the FETs to their “on” states or “off” states at predetermined times.

Abstract: A system and method for managing a 4 leg transformerless Uninterrupted Power Supply is disclosed. The system comprises a 3 leg inverter modulation signal generator that applies signals to a modulation circuit that generates a 4th leg modulation signal based on the applied 3 leg inverter modulation signal characteristics. The determined 4th modulation signal modifies the 3 leg inverter modulation signals and rectifier modulation signals, which are applied to corresponding inverter and rectifier sections of an Uninterruptible Power Supply.

Abstract: A timing controlled converter for converting a time varying input signal to a regulated DC output voltage for application to a load circuit. A feedback loop is employed as a control means for switchably coupling the time varying input signal to the load circuit for controlled periods of time in a manner so as to provide an average load voltage equal to a reference voltage. The duration of the controlled periods of time is a function of: the difference between the time varying input signal and the output voltage; and the integral of the difference between the output voltage and the reference voltage.

Abstract: The invention relates to a power supply system (3) intended to supply power to an electrical load (C), the system comprising: two input terminals, namely a negative terminal and a positive terminal, connected to a supply mains (A) delivering an AC voltage; an input capacitor (C1) connected to one of the terminals of the system; a rectifier module (33) for generating a DC voltage on a DC bus from the AC voltage; a bus capacitor (Cb) connected between a positive line (31) and a negative line (32) of the DC bus, and upstream of the input capacitor (C1), two normally-on bidirectional semiconductor transistors (T1, T2) connected in series, fabricated in a wide-bandgap material and able to operate in current-limiting mode.

Abstract: An active rectifier (12) couples a first input voltage (Vin1) to a first electrode of a first transistor (M3) having a second electrode coupled to an output (4) conducting an output voltage (Vout), and couples a second input voltage (Vin2) to a first electrode of a second transistor (M4) having a second electrode coupled to the output conductor. A first amplifier (A1) controls a voltage (V16) of a gate of the first transistor to maintain an input offset of the first amplifier between the first input voltage and the output voltage while the first input voltage exceeds the output voltage, and a second amplifier (A2) controls a voltage (V15) on a gate of the second transistor to maintain an input offset between the second input voltage and the output voltage while the first input voltage exceeds the output voltage. The input offsets prevent backflow of current from the output to either of the first electrodes when the first or second input is nearly equal to the output voltage.

Abstract: The invention relates to a current-source power converter comprising, in its rectifier module (20) and/or its inverter module, switching legs equipped with normally-on field effect transistors (T1-T6, Q1-Q6) each controlled by a gate control device (CT1, CT2). The invention has the particular feature of a normally-open auxiliary switch (SW) placed in series with the switching legs and connected to the positive line (10) of the power supply bus. This auxiliary switch is intended to prevent the mains (R) from short-circuiting during start-up or during malfunction of the auxiliary power supply (AUX).

Abstract: Embodiments of a ground power unit are disclosed for providing power to a grounded vehicle, such as an aircraft. In accordance with certain embodiments, the ground power unit (GPU) accepts a wide range of AC input voltages and is capable of providing a range of DC output voltages. The GPU may include a switched rectifier that converts an AC input signal to a DC link signal. The DC link signal is then converted to a switched DC signal that simulates an AC-like sine wave using a high frequency DC-to-DC switching converter. A single-phase transformer modulates and isolates the switched DC signal, which is subsequently converted to a DC output signal using diode rectifiers coupled to the secondary winding of the transformer. The disclosed GPU may be controlled using a software-based control algorithm that controls the AC input parameters independently of the DC voltage parameters.

Abstract: The present invention provides an AC-DC converter and AC-DC conversion method for converting an AC input provided by a power transfer winding. The AC-DC converter includes a rectifying means for rectifying the AC input into a rectified output, and a control means for controlling the rectifying means based on a comparison between a reference signal and a voltage feedback signal, the voltage feedback signal being based on the rectified output.

Abstract: A current controlled synchronous rectifying drive circuit including a current transducer ST having a primary winding connected in series with a synchronous rectifier SR and having a secondary winding to detect a current signal of a synchronous rectifier SR, a signal shaping and reset circuit connected to the secondary winding of the current transducer ST to convert the synchronous rectifier SR's current signal into a voltage signal and shapes it into a pulse signal, a push-pull power amplifying circuit having an input end connected to the signal shaping and reset circuit and an output end connected to a gate of the synchronous rectifier SR to amplify a drive signal generated by the signal shaping and reset circuit to drive the synchronous rectifier SR, and a drive self-bias drive circuit having an input end connected to the secondary winding of the current transducer ST and an output end connected to the push-pull power amplifying circuit to store energy from the current transducer ST to generate a voltage so

Abstract: A synchronous rectifier control device comprises a status detecting unit, an analog circuit, a first counter, a second counter and a signal process unit. The status detecting unit receives at least one reference signal and a detecting signal to generate a first synchronous control signal. The analog circuit generates a delay signal in accordance with the first synchronous control signal. The first counter receives a clock signal and generates a first counter signal in accordance with the first synchronous control signal, the clock signal, and the delay signal. The second counter receives the clock signal and generates a second counter signal in accordance with the first synchronous control signal, the clock signal, and the first counter signal. The signal process unit generates a second synchronous control signal in accordance with the first synchronous control signal and the second signal.

Abstract: Embodiments of the present invention provide cross-coupled rectifiers that use near zero-threshold transistors in a switching topology, but provide a topology that avoids reverse conduction problems. Importantly, preferred embodiment rectifiers of the invention only provide a slightly increased on-resistance in each branch, while providing both very high operating efficiency and very low turn-on voltage. An embodiment of the invention is a voltage rectifier for the conversion of RF energy into DC voltage with a turn-on threshold voltages approaching 0V.

Abstract: The control circuit comprises: a detecting portion COMP1 for detecting a status transition of a first signal FR at the connecting point P which changes at a constant cycle corresponding to current flowing through the antiparallel diode D when the main switch device FET is turned OFF; and a phase difference adjusting portion 30, 40 for adjusting the phase difference by adjusting the output timing of the second signal FP corresponding to a phase difference between the phase of the first signal FR detected by the detecting portion COMP1 and the phase of the second signal FP generated based on the first signal of one cycle before and the rectification switch device FET2 is turned ON corresponding to the second signal FP whose output timing is adjusted by the phase difference adjusting portion 30, 40.

Abstract: A matrix converter that can be used as part of a two-stage power converter has three ac three ac voltage lines AC1, AC2 and AC3 and two dc voltage lines DC1 and DC2. An array of six semiconductor switches 10a to 10f are arranged such that each of the three ac voltage lines AC1, AC2 an AC3 can be connected to one of the two dc voltage lines DC1 and DC2 when the associated switch is closed. A freewheel path is provided between the two dc voltage lines DC1 and DC2, which provides a fifth state of operation when all the switches 10a to 10f are open.

Abstract: The temperature dependence of detection characteristics in a wave detector circuit is suppressed. A bias resistor and/or a load resistor are/is constituted by a resistive element having a high temperature coefficient, whereby a shift in detected output along with a change in temperature of a wave detector diode included in a diode detector circuit is canceled by a shift in detected output along with a change in temperature of the bias resistor and/or a shift in detected output along with a change in temperature of the load resistor.

Abstract: A multi-level converter to at least convert an AC switched voltage available on a switched voltage point into at least five DC voltage levels available on positive and negative DC voltage lines, said converter comprising two separate switching units to convert respectively positive and negative half-waves of said switched voltage, connected to the DC voltage lines respectively presenting positive and negative DC voltage levels, and wherein each switching unit comprises a switching point connected to said switched voltage point by means of change-over means. An uninterruptible power supply comprising said converter.

Abstract: A regulator with decreased leakage and low loss for a power amplifier is described. Switching circuitry is used to connect the regulator input bias to a bias control voltage when the power amplifier is to be operated in an on condition or to a voltage generator when the power amplifier is to be operated in an off condition.

Abstract: A multi-voltage power supply includes a transformer, a first output circuit to generate a first output voltage using a voltage transferred to a secondary winding of the transformer, and a first output voltage controller to control a voltage supplied to the primary winding of the transformer according to the first output voltage. The multi-voltage power supply includes second through Nth output circuits to generate second through Nth output voltages using the voltage transferred to the secondary winding of the transformer, and second through Nth output voltage controllers performing control in order to linearly output the second through Nth output voltages by feeding back the second through Nth output voltages.

Abstract: A rectifier connected with an AC source through a reactor, a plurality of capacitors connected in series between output terminals of the rectifier, first switching means connected between one input terminal of the rectifier and a connection point of a plurality of capacitors, second switching means connected between the other input terminal of the rectifier and the connection point of a plurality of capacitors, and a plurality of diodes connected with the plurality of capacitors in inverse-parallel are provided.

Abstract: A synchronous rectification circuit for a power converter includes a power switch coupled to a transformer and an output capacitor and a switching control circuit configured to provide a control signal to the power switch in response to a first state and a second state of the voltage across the power switch. In the switching control circuit, the second state is determined prior to the first state is determined. In an embodiment, the switching control circuit includes a voltage comparing unit configured to act in response to the first and second inputs. The voltage comparing unit is also configured to output a logic signal according to the voltage difference between the sensed voltage drop across the power switch and a reference threshold voltage. A logic processing circuit is coupled to the voltage comparing unit and configured to provide the first state and the second state of the voltage across the power switch.

Abstract: Systems and methods for synchronous rectifier control are provided. A synchronous rectifier includes parasitic drain inductance and parasitic source inductance. Compensation inductance is introduced to offset the effects of parasitic inductance. Compensation inductance may be formed from the trace inductance on the semiconductor die. In certain semiconductor packages, the parasitic inductance may be substantially fixed such that the layout can be modified to generate fixed compensation inductance.

Abstract: A drive unit for electrical loads is provided. The drive unit may include an insulating transformer having a secondary winding for an alternate current to flow therethrough, wherein said secondary winding of said insulating transformer is coupled to electronic switches in a synchronous rectifier arrangement, said electronic switches to be alternatively switched on and off as a function of a trigger signal to produce a rectified output signal from said alternate current flowing through said secondary winding, wherein the unit includes a sense inductance coupled via a set of conductive strips to the secondary winding of said insulating transformer to sense the zero crossings of said alternate current flowing through said secondary winding and generate therefrom said trigger signal for said synchronous rectifier arrangement.

Abstract: A rectifier driving circuit of the present invention, has a first driving element and a second driving element, switching element comprises a FET, a first driving element comprises the voltage drop resistor, a second driving element comprises the series-connected circuit of the diodes, the driving element for driving a FET, may be achieved rectify function.

Abstract: An integrated circuit (IC) comprises a rectifier/regulator circuit coupled to receive an ac source voltage and output a regulated dc voltage. The rectifier/regulator circuit includes first and second switching elements that provide charging current when enabled. The first and second switching elements do not provide charging current when disabled. A sensor circuit is coupled to sense the regulated dc voltage and generate a feedback control signal coupled to the rectifier/regulator circuit that enables the first and second switching elements when the regulated dc voltage is above a target voltage, and disables the first and second switching elements when the regulated dc voltage is below the target voltage.

Abstract: A synchronous rectifier is arranged to rectify inductively coupled power using FETs (field effect transistors) to minimize the voltage drop of the rectifier, which minimizes power loss. Power loss is an important consideration in applications where fairly significant power is coupled to a device (such as a battery charger or other energy storage device) for a fairly short time (such as less than one hour) at a fairly low voltage (such as around 2.5 to 4.5 volts). Body diodes of the FETs can be used to supply power for bootstrapping and control logic for controlling the FETs.

Abstract: A power factor correction converter includes a diode bridge arranged to perform full-wave rectification on an AC input power supply, a switching element arranged to perform switching on an output voltage thereof, an inductor arranged to pass a current interrupted by the switching element and to accumulate and emit excitation energy, a diode, and a smoothing capacitor defining a step-up chopper circuit. A digital signal processing circuit detects a phase of an input voltage, and a switching frequency of the switching element is modulated in accordance with the phase. Accordingly, the switching frequency can be appropriately modulated without depending on an input voltage, so that a wide range of input voltages can be accepted while suppressing EMI noise with a peak generated in the switching frequency and higher-order frequency components thereof.

Abstract: A four pole, three-phase, NPC converter that produces virtually no common mode voltage. The low common mode voltage output is achieved by constraining the switch states of the NPC converter. A fourth pole and associated control balance the upper and lower DC link voltages. The converter may be an inverter or a rectifier.

Abstract: A three-phase bridge rectifier circuit (TPBRC) connectable to an AC voltage source (102, 104, 106) via input lines (151, 153, 155) and to a load (199) via output lines (159, 157). The AC voltage source supplies the TPBRC (100) with AC voltage waveforms (302, 304, 306) that differ in phase by a certain amount. The TPBRC includes three series transistor combinations (110/112, 114/116, 118/120) connected across the output lines. A plurality of diodes (190, 128, 198, 148, 113, 168) are connected between a drain (152, 122, 162, 132, 172, 142) of one of the field effect transistors (110, 112, 114, 116, 118, 120) and a gate (154, 124, 164, 134, 174, 144) of a different one of the field effect transistors. A voltage divider (192/188, 130/140, 107/196, 150/160, 115/111, 170/180) and a voltage clamping device (194, 138, 109, 158, 119, 178) is provided for each field effect transistor.

Abstract: A three-phase bridge rectifier circuit (BRC) connectable to an AC voltage source (ACVS) via input lines (151, 153, 155) and a load (109) via output lines (157, 159). ACVS (102, 104, 106) supplies BRC (100) with AC voltage waveforms that differ in phase. The BRC includes a three-phase bridge rectifier circuit comprised of field effect transistors (FET) and gate drive circuits (GDC). Each GDC (101a, 103a, 101b, 103b, 101c, 103c) supplies a voltage to a gate of a respective FET (110, 112, 114, 116, 118, 120) for switching the FET to its “on” state at a certain time. The BRC further includes a diode (190, 128, 198, 148, 113, 168) connected between a drain of each FET and a terminal of each GDC. The BRC can further include voltage divider circuits (192/188, 130/140, 107/196, 150/160, 115/111, 170/180) and/or voltage clamping devices (121, 131, 123, 133, 125, 135).

Abstract: A power conversion apparatus includes a converter having an input power source Vin, a reactor L1, a switching element Q1, and a rectifying element D1, a smoothing capacitor C1 connected to an output terminal of the converter, and a controller 10b to turn on/off the switching element and thereby control power to be outputted from the converter. The controller has a pulse generator 15 to generate a pulse signal according to an input voltage to the converter and an output voltage from the converter, the pulse signal being used to turn on/off the switching element. The controller also has an adjuster 18 to mask an ON time of the pulse signal for a predetermined time and thereby provide the pulse signal with an adjusted ON time, the adjusted ON time determining a duty ratio at which the switching element is turned on/off.

Abstract: A synchronous rectification control device achieves high power conversion efficiency without supplying additional signal to a secondary side from a primary side. An insulated type switching power supply provides such a synchronous rectification control device. An output power is regulated based on a phase difference between two half bridges in the primary side. In the secondary side of the full bridge converter circuit, a center tap is lead out from the secondary windings of a transformer to obtain two symmetrical sections of windings. A device for detecting winding voltage observes winding voltages at terminals of the sections of windings. The synchronous rectification control circuit controls transistors and MOSFETs connected to the secondary windings to make the transistor in the ON or OFF state depending on the current flow in the secondary windings.