Abstract: A burst mode control method for a resonant converter is provided, in which at least one first regulation pulse is provided to pre-adjust a magnetizing inductor current and a resonant capacitor voltage in a resonant circuit during a burst mode working period. After the first regulation pulse is completed, at least one pulse group including a plurality of driving pulses is provided to intermittently turn on switching elements of a square wave generator. The first regulation pulse adjusts the magnetizing inductor current and the resonant capacitor voltage, such that the magnitude of the magnetizing inductor current is essentially the same and the magnitude of the resonant capacitor voltage is essentially the same at each rising edge of each driving pulse of the pulse group.

Abstract: The present invention discloses a power stage control circuit including: a driver circuit for controlling a power stage according to an error amplified signal; an error amplifier circuit for comparing a feedback voltage at a feedback terminal with a reference signal to generate the error amplified signal; a current generator circuit coupled to the feedback terminal for generating a fault detection current flowing to the feedback terminal; and a feedback terminal short detection circuit for generating a fault signal to stop the operation of the power stage when the feedback voltage is smaller than a short-circuit threshold voltage or when the fault detection current is larger than a short-circuit threshold current.

Abstract: This document discusses, among other things, apparatus and methods for controlling a converter. In an example, a voltage-controlled oscillator (VCO) can be configured to provide a first pulse train to control the converter. The frequency of the first pulse train of the VCO can be modulated using information indicative of an operating condition of the converter to maintain a desired DC voltage at an output. In an example, the VCO can include a frequency divider configured to provide a second pulse train to the output using information from the first pulse train.

Abstract: An open loop half-bridge LLC power converter includes circuitry to reliably increase hold-up time without sacrificing efficiency. An LLC resonant circuit includes resonant inductance, a primary transformer winding, and resonant capacitance. An auxiliary circuit includes an auxiliary transformer winding, an inductor, and a third switching element coupled in series. A controller is coupled across a voltage sensor and effective thereby to determine a holdup time condition. In a “normal” operating condition the controller generates switch driver signals to turn OFF the third switching element and disable the auxiliary circuit, and in a hold-up time condition the controller turns ON the third switching element and enables the auxiliary circuit wherein the output voltage is increased via current supplied from the auxiliary winding. In various embodiments the auxiliary winding may be an auxiliary primary or secondary, or a secondary to an auxiliary primary winding of a second transformer.

Abstract: A system is provided having a first LLC power converter and a second LLC power converter. The first LLC power converter comprises a first LLC voltage source. The second LLC power converter also comprises a second LLC voltage source. The first LLC power converter also comprises a first resonant inductor, a first magnetic inductor, and a first resonant capacitor coupled to the first voltage source of the first LLC power converter. The second LLC power converter comprises a second resonant inductor, a second magnetic inductor, and a second resonant capacitor coupled to the second voltage source of the second LLC power converter. The first LLC power converter and the second LLC power converter are both magnetically couplable to a common load. A resonance of the first LLC power converter substantially matches a resonance of the second LLC power converter.

Abstract: A soft switching apparatus comprises an energy recovery channel formed by two diodes in series connection and a resonant tank formed by an inductor and a capacitor. The soft switching apparatus is coupled to the primary side of a bridge converter. An energy transfer process during L-C resonance helps to reduce the amplitude of the current flowing through the inductor in a freewheeling period. Furthermore, the soft switching apparatus can help to reduce the voltage stress across the secondary switching devices as well as the shoot-through currents flowing through the secondary switching devices, and thus enabling the reduction or elimination of dead time in a secondary synchronous rectifier control scheme.

Abstract: A method of operating a resonant power supply in standby mode is disclosed, in which the switching period of the power supply is longer than the resonance period. The power converter is operated in normal mode for a significant fraction of one resonance period. Efficient operation is maintained, despite the switching period being extended beyond the resonance period, by using resonance current to enable soft switching, where this is beneficial, and dumping the resonance current into the load where this is more beneficial. Control methodologies to regulate the output power are also disclosed.

Abstract: A converter circuit has a first resonant converter that is connected on the DC voltage side to a first energy storage circuit, and a transformer. A second resonant converter is connected on the AC voltage side to the secondary winding of the transformer and on the DC voltage side to a load converter, and a CLL resonant circuit is connected to the first resonant converter and to the primary winding of the transformer. The CLL resonant circuit has a resonant capacitance, a first resonant inductance and a second resonant inductance.

Abstract: A resonant-mode power supply comprising an integrated inductor (ZER), the integrated inductor (ZER) comprising an inductor (IR) and a transformer (TR). The main internal winding (1) of the transformer (TR) is surrounded by magnetic elements (2, 3) for closing the magnetic flux lines around the main internal winding (1) of the transformer (TR), wherein at least one magnetic element (2, 3) is surrounded by at least one auxiliary external winding (4) of the inductor (IR) arranged orthogonally to the main internal winding (1) of the transformer (TR), and the power supply being configured such that during operation the current (I1) flowing through the inductor (IR) is shifted in phase with respect to the current (I2) flowing through the primary winding of the transformer (TR).

Abstract: An active snubber circuit for a power converter, a method of operating the same and an inductor inductor capacitor converter incorporating the circuit or the method. In one embodiment, the circuit includes: (1) a series-coupled first capacitor and diode associated with a secondary-side switch in the power converter and coupled to an output thereof and (2) an active snubber circuit switch coupled in parallel with the diode and configured to receive a control signal that closes the active snubber circuit switch during at least a portion of a time during which the secondary-side switch is open.

Abstract: A constant current power supply device according to the present invention includes: an error amplifier to amplify an error signal of an error voltage between a voltage of a current detection resistor and a reference voltage, and a second control circuit to sample and hold the error signal in an ON period of the external signal, output the error signal to a first control circuit, hold the error signal just before the external signal is turned from ON to OFF, increase an amplification ratio of the error amplifier by a predetermined magnification ratio in an OFF period of the external signal, and output the increased error signal to the first control circuit.

Abstract: In a switching power supply apparatus, a low-side switching device is connected in series with a primary winding. A high-side switching device and the primary winding define a closed loop. A voltage induced in a high-side drive winding is applied to the high-side switching device to turn on the high-side switching device. A transistor, which is turned on/off in accordance with the voltage across a capacitor charged by the voltage induced in the high-side drive winding, is connected to the gate terminal of the high-side switching device. When the capacitor is charged and the transistor is turned on, the high-side switching device is turned off. The capacitor is discharged by the voltage induced in the high-side drive winding, during the ON period of the low-side switching device.

Abstract: A switching power-supply circuit includes a transformer, a first switching element, a first rectifying/smoothing circuit generating a first output voltage by rectifying and smoothing the output of a first secondary winding, a second rectifying/smoothing circuit generating a second output voltage by rectifying and smoothing the output of a second secondary winding, a first feedback circuit generating a feedback signal according to the first output voltage, and a first switching control circuit. When the voltage of the second secondary winding is greater than the second output voltage and the second output voltage is less than the voltage of a reference-voltage circuit, a second rectifier circuit turns on a rectifier switch element, and stabilizes the second output voltage by controlling the number of pulses per unit time in a pulse current flowing through the second rectifier circuit.

Abstract: Provided is a current sensing signal comparing device and current sensing signal comparing method. The current sensing signal comparing device includes a current sensing circuit for detecting a current signal of a switching circuit and thereby generating a current sensing signal, a control unit for outputting a control signal, and a compensating circuit for compensating the current sensing signal according to the control signal. The compensated current sensing signal is compared with a constant current reference signal in order to issue a constant current control signal. The device can also be provided to configure the compensating circuit to compensate the constant current reference signal, such that the current sensing signal is compared with the compensated constant current reference signal in order to issue a constant current control signal.

Abstract: A resonant power converting circuit is provided, which includes a resonant converting unit, a control unit, a current detecting unit and a frequency modulation unit. The control unit outputs switching signals to the resonant converting unit to adjust an output thereof. The current detecting unit is configured to detect an output current of the resonant converting unit. The frequency modulation unit may adjust a lowest switching frequency of the control unit according to the detected output current so as to increase a gain of the resonant converting unit and an output stability of the resonant converting unit.

Abstract: A switching power-supply apparatus includes a first converter 3, a second converter 4, an output smoothing capacitor Co1, a series resonance circuit 1 and a control circuit 11. The first converter 3, in which switching elements Q11 and Q12 are connected to both ends of a direct-current power-supply Vin in series, and a capacitor Ci1 and a primary winding Np1 of a transformer T1 including an auxiliary winding Na1 are connected to both ends of the switching element Q12 in series, includes diodes D11 and D12 that rectify voltages generated in secondary windings Ns11 and Ns12 of the transformer T1. The second converter 4, in which switching elements Q21 and Q22 are connected to the both ends of the direct-current power-supply Vin in series, and a capacitor Ci12 and a primary winding Np2 of a transformer T2 are connected to both ends of the switching element Q22 in series, includes diodes D21 and D22 that rectify voltages generated in secondary windings Ns21 and Ns22 of the transformer T2.

Abstract: An adaptive inductive ballast is provided with the capability to communicate with a remote device powered by the ballast. To improve the operation of the ballast, the ballast changes its operating characteristics based upon information received from the remote device. Further, the ballast may provide a path for the remote device to communicate with device other than the adaptive inductive ballast.

Abstract: A power supply device comprises a capacitance (Ca) consisting of an overhead power line (100) and an electrode (20) extending in the longitudinal direction of the overhead power line (100) via an insulator (30), an inductance (La) connected in parallel with the capacitance (Ca), and an output portion (50) led out from both ends of a parallel circuit including the capacitance (Ca) and the inductance (La). The parallel circuit is operated as a parallel resonant circuit and power is supplied from the output portion (50), thereby obtaining a compact and simple structure and improving power supply efficiency to a load as compared with a conventional power supply device.

Abstract: In a power supply with n interlaced conversion cells, a control device activates m paths out of n paths, 1?m?n, as a function of the power or of the current handled by the power supply. The cell may have a boost, buck, buck/boost, Cuk, or SEPIC topology.

Abstract: A power supply apparatus and method of regulating is provided. A converter circuit includes a primary switching element and an auxiliary switching element. The auxiliary switching element is for transferring a reflected voltage signal. A transformer includes a primary and a secondary, the primary is coupled with the converter circuit. The converter circuit comprises a primary and an auxiliary switch for selectively determining a resonant frequency. The auxiliary switch is enabled by a driver having an independent power source so as to allow as strong a driver as necessary to drive a large auxiliary switch.

Abstract: A control method is provided for controlling an asymmetric DC-DC converter including first and second power switches that are driven respectively by first and second control signals, and a voltage-converting circuit that is operatively associated with the first and second power switches for generating an output signal. The voltage-converting circuit includes a primary coil unit and a secondary coil unit operatively associated therewith for voltage conversion, and including first and second coils that have a turn ratio not equal to one. The control method includes: sampling the output signal to obtain a sample signal corresponding thereto; and generating the first and second control signals, which correspond respectively to first and second duty cycles having a sum of one, based on a comparison between the sample signal and a reference signal such that the first and second power switches are driven in an alternating manner.

Abstract: A synchronous operating system for operating a plurality of discharge tube lighting apparatuses at the same frequency and same phase includes (1) an oscillator of a triangular wave signal whose inclination for charging a capacitor C2 and inclination for discharging the same are the same, (2) a signal generation part to generate, in a period shorter than a half period of the triangular wave signal, a first drive signal having a pulse width corresponding to a load current, and (3) a signal generation part of a second drive signal having a pulse width substantially equal to that of the first drive signal and a phase difference of about 180 degrees with respect to the same.

Abstract: A three phase full resonant cyclo-converter suitable for converting a three phase AC supply to a DC output. In one embodiment the cycloconverter controls switching frequency to control converter output and adjusts phase on times for power factor correction. A switching sequence is employed which provides resonant switching to reduce losses and component ratings. The converter provides high conversion efficiency with a simple power component design.

Abstract: A controller for use in an LLC resonant converter is disclosed. An example controller is controlled by detecting a maximum frequency signal to set a maximum switching frequency of the LLC resonant converter. A burst stop frequency and a burst start frequency are programmed in response to the maximum switching frequency. The burst stop frequency and the burst start frequency are fractions of the maximum switching frequency. The LLC resonant converter is switched in response to a feedback signal to regulate an output of the LLC resonant converter. The steps of switching the LLC resonant converter in a burst mode in response to the feedback signal reaching a value corresponding to the programmed burst start frequency and of stopping the switching of the LLC resonant converter in the burst mode in response to the feedback signal reaching a value corresponding to the programmed burst stop frequency are repeated.

Abstract: Disclosed herein are a converter driving circuit for adjusting a variable range of a driving control voltage according to an amplitude and frequency change of a feedback voltage, a dual-mode LLC resonant converter system, and a method of driving the dual-mode LLC resonant converter.

Abstract: A power converter includes a first inductor, a rectifier arm, a first switch arm including a first and second switch circuits, a second switch arm including a third switch circuit and a first capacitor, a LC serial circuit, a Transformer, a rectification and smoothing circuit connected to secondary winding of the transformer, and a control circuit to perform on-off control of the three switch circuits. The rectifier arm, the first and second switch arms and the LC serial circuit are connected in parallel with each other. The LC serial circuit and primary winding of the transformer are connected. AC power supply is connected to the rectifier arm via the first inductor. The control circuit includes an output voltage control circuit to control output voltage at specific setting value, an intermediate voltage control circuit to control intermediate voltage at specific setting value, and a power factor correction control circuit.

Abstract: The primary of a transformer is driven at low voltages to provide high-voltage dynamic drive from the secondary to a load. A high-current source is placed in series with both the transformer secondary and load. At least secondary inductance of the transformer, hence impedance, is controlled through core saturation to transition secondary output to the load between high-voltage dynamic drive inductively coupled from the primary, and high-current drive serially connected through the secondary. Switching between high voltage and high current output is accomplished through the transformer; no additional switching devices need exist in the high-voltage path. Broad voltage and current capabilities of the configuration inexpensively improve transient drive of highly reactive loads.

Abstract: A drive circuit arranged to drive a synchronous rectifier of a power converter includes a differential amplifier stage connected to the synchronous rectifier and arranged to supply a drive signal to the synchronous rectifier to turn the synchronous rectifier on and off and a high voltage blocking stage connected between the synchronous rectifier and the differential amplifier stage. The differential amplifier stage is arranged such that a voltage level of the drive signal depends on a load of the power converter.

Abstract: A controller for a power converter is provided. The controller includes a PWM circuit, a detection circuit, a signal generation circuit and an oscillation circuit. The PWM circuit generates a switching signal coupled to switch a transformer of the power converter. A feedback signal is coupled to the PWM circuit to disable the switching signal. The detection circuit is coupled to the transformer via a resistor for generating a valley signal in response to a signal waveform of the transformer. The signal generation circuit is coupled to receive the feedback signal and the valley signal for generating an enabling signal. The oscillation circuit generates a maximum frequency signal. The maximum frequency signal associates with the enabling signal to generate a pulse signal. The feedback signal is correlated to an output load of the power converter. The maximum frequency of the pulse signal is limited.

Abstract: A control circuit for a voltage converter including a power switch for providing power to a load in accordance with an embodiment of the present application includes a driver circuit operable to provide a first control signal to the power switch to turn the power switch on and off such that a desired voltage is provided to the load, an output terminal connected to the driver circuit and operable to connect the driver circuit to the power switch; and a controller operable to control the driver circuit. The output terminal operates as an input terminal to receive external data under predetermined conditions, and the controller controls the driver circuit based on the external data.

Abstract: An electric power supply apparatus, which enables a driving frequency of a switching circuit connected to a primary side of a transformer constant and output of a secondary side variable, comprises a transformer (5), a series circuit of two first switching elements (Q1, Q2) connected between terminals of a direct current power supply (2), an LC resonant circuit connected between both ends of one of the first switch element (Q2) and a primary winding (Np) of the transformer (5), bidirectional switch elements (Q3, Q4) connected to secondary windings (Ns1, Ns2) of the transformer (5) and having a rectification function and a phase control function, and a control circuit for inputting gate driving signals having a phase difference into the first switch elements (Q1, Q2) and the second switch elements (Q3, Q4).

Abstract: There is provided an LLC type power supply apparatus for controlling switching of a secondary side rectifier based on primary side current, particularly, controlling switching of the secondary-side rectifier based on primary side resonance current and magnetizing current. The power supply apparatus includes: a switching unit switching input power; a transformer unit transforming the switched power from the switching unit; a rectifying unit including a rectifier turned on and turned off in response to a control signal to rectify the transformed power; a controlling unit controlling the switching of the switching unit, based on an output power of the rectifying unit; and a switching controlling unit controlling turning-on and turning-off of the rectifier of the rectifying unit, based on current flowing in the transformer unit.

Abstract: A method for controlling operation of a resonant converter is to be implemented by a control module that generates a drive signal for controlling a power switch of the resonant converter to thereby control an output voltage and an output current provided by the resonant converter to a load. The method includes: (A) configuring the control module to determine if the load is operating in a first mode or a second mode; (B) configuring the control module to generate the drive signal according to the output voltage when the control module determines that the load is operating in the first mode; and (C) configuring the control module to generate the drive signal according to the output current when the control module determines that the load is operating in the second mode.

Abstract: A high voltage power supply is provided. The high voltage power supply includes an inverter which converts a DC voltage input to the high voltage power supply into a first AC voltage, a transformer including an input winding unit and a plurality of output winding units, wherein the input winding unit receives the first AC voltage from the inverter and the plurality of output winding units generates and outputs a second AC voltage, and a voltage multiplier unit which boosts the second AC voltage output by the transformer and outputs a boosted voltage, and the voltage multiplier unit includes a plurality of voltage multipliers which are connected to each other in series and the plurality of voltage multipliers may be connected to the plurality of output winding units respectively.

Abstract: Provided are methods, circuits, and systems for obtaining power from a power generator such as a photovoltaic cell or a fuel cell. The methods, circuits, and systems comprise converting substantially DC output power from the power generator into a high frequency AC voltage while rejecting or minimizing oscillations in the output power from the power generator; converting the high frequency AC voltage into a high frequency substantially sinusoidal voltage or current; and converting the high frequency substantially sinusoidal AC voltage or current into (i) a DC voltage or current, and (ii) a low frequency substantially sinusoidal AC voltage or current; wherein the high frequency substantially sinusoidal AC voltage or current is isolated from the DC voltage or current or the low frequency substantially sinusoidal AC voltage or current.

Abstract: A two-stage insulated bidirectional DC/DC power converter is disclosed. A two-stage insulated bidirectional DC/DC power converter according to an embodiment of the invention has the characteristic of including: an LLC resonant converter operating at a constant duty ratio; a bidirectional converter joined to a front part of the LLC resonant converter and configured to perform a booster converter function of outputting the input voltage at a consistent input voltage for the LLC resonant converter, and a buck converter function of reducing the voltage by way of the LLC resonant converter and then outputting a consistent voltage; and a bidirectional converter control unit configured to control changes in an input voltage of the bidirectional converter and regulate an output voltage of the LLC resonant converter to thereby maintain a consistent input voltage of the LLC resonant converter, such that the LLC resonant converter operates at a constant duty ratio.

Abstract: Provided are a resonance and PFC integrated control IC and a power converter. The resonance and PFC integrated control IC includes an interleave PFC control block and a resonance control block. The interleave PFC control block is configured to control first and second switches of an interleave switching converter and correct a power factor. The interleave switching converter includes a first converter comprising the first switch and a second converter comprising the second switch, and the first converter and the second converter are connected in parallel. The resonance control block is configured to resonate and control a Direct Current (DC)-DC converter that receives and converts the output of the interleave switching converter.

Abstract: A DC-AC converter is provided. The DC-AC converter includes a time-varying DC power generating circuit, an AC power generating circuit and a transmission capacitor. The time-varying DC power generating circuit is controlled by a pulse width modulation (PWM) signal to transform a DC source into a time-varying DC power. With reference to the time-varying DC power, the AC power generating circuit is controlled by a first polarity switching and a second polarity switching signal to generate an AC power. The transmission capacitor, coupled to the time-varying DC power generating circuit and the AC power generating circuit, transmits the time-varying DC power from the time-varying DC generating circuit to the AC power generating circuit.

Abstract: A circuit for an oscillator structured to drive a control device of a switching resonant converter; the converter having a switching circuit structured to drive a resonant load provided with at least one transformer with at least a primary winding and at least a secondary winding. The control device structured to drive the switching circuit, and the converter structured to convert an input signal into an output signal, the integrated circuit includes a first circuit structured to charge and discharge a capacitor by a first current signal such that the voltage at the ends of the capacitor is between first and second reference voltages, the current signal having a second current signal indicating the output voltage of the converter; the integrated circuit including a second circuit structured to rectify a signal indicating the current circulating in the primary winding.

Abstract: A resonant DC-DC converter used to drive an LED array includes a half-bridge converter configured to receive DC input power and produce a square wave voltage. A resonant tank circuit that includes an inductive element, a first resonance capacitor, and a second resonance capacitor, is coupled to the half-bridge converter to receive the square wave voltage such that a generally sinusoidal AC voltage is produced across the second resonance capacitor. An output transformer with a primary winding and one or more secondary windings, is coupled in parallel to the second resonance capacitor, and a clipping circuit is coupled to the primary winding such that the voltage across the primary winding does not substantially exceed the voltage of the DC input power. An output rectifier is coupled to the one or more secondary windings of the output transformer and is configured to produce a generally DC output voltage.

Abstract: A method and a control device control a switching device for providing a resonant circuit with a switching voltage for generating a resonant current in order to provide a required output power at an output of a resonant power converter.

Abstract: The resonant converting circuit comprises a resonant circuit, a current detecting circuit and the resonant controller. The resonant controller controls a power conversion of the resonant circuit for converting an input voltage into an output voltage and the resonant controller comprises an over current judgment unit and an over current protection unit. The over current judgment unit determines whether the resonant current is higher than an over current value according to a current detecting signal generated by the current detecting circuit. The over current protection unit generates a protection signal in response to a determined result of the over current judgment unit and an indication signal indicative of an operating state of the resonant controller. The resonant controller executes a corresponding protecting process in response to the protection signal.

Abstract: A semiconductor arrangement includes a circuit carrier, bonding wire and at least N half bridge circuits. The circuit carrier includes a first metallization layer, a second metallization layer, an intermediate metallization layer arranged between the first metallization layer and the second metallization layer, a first insulation layer arranged between the intermediate metallization layer and the second metallization layer, and a second insulation layer arranged between the first metallization layer and the intermediate metallization layer. Each half bridge circuit includes a controllable first semiconductor switch and a controllable second semiconductor switch. The first semiconductor switch and the second semiconductor switch of each half bridge circuit are arranged on that side of the first metallization layer of the circuit carrier facing away from the second insulation layer. The bonding wire is directly bonded to the intermediate metallization layer of the circuit carrier at a first bonding location.

Abstract: An AC-DC converter is disclosed. The AC-DC converter includes an OFF-time clamping circuit. The OFF time clamping circuit outputs a triggering signal when a main switch circuit of the AC-DC converter is switched from ON state to OFF state. When an input AC voltage is too small, and a terminal voltage at a first current-conducting terminal of the main switch circuit of the AC-DC converter is lower than a specific voltage such that a switching control circuit can not turn on the main switch circuit again, the switching control circuit can still turn on the main switch circuit again by the triggering signal. Therefore, the OFF time of the main switch circuit is clamped. The switching control circuit can control the switching operation of the main switch circuit.

Abstract: A series resonant converter of the present invention includes an inverter circuit having at least a pair of a first and second switching device connected between two input terminals, a transformer having a primary winding and a secondary winding connected to the inverter circuit, a first and second resonant capacitor connected to a secondary side of the transformer and connected in series to each other between two output terminals, a first and second unidirectional device connected in series to each other, and a resonant induction device that is operated along with the first and second resonant capacitor and resonates in series. The first and second unidirectional device are configured such that current does not flow from the first and second resonant capacitor to the input terminal by preventing electric charge of the first and second resonant capacitor from being discharged to a primary side of the transformer.

Abstract: A pseudo-resonant switching power source device is provided which comprises a primary winding 2a of a transformer 2 and a main MOS-FET 3 connected in series to a DC power source 1, a voltage-resonant capacitor 12 connected in parallel to main MOS-FET 3, a rectification smoother 4 connected to a secondary winding 2b of transformer 2 and having a rectification MOS-FET 51 and a smoothing capacitor 6, a synchronized rectification controller 52 for turning rectification MOS-FET 51 on after turning-off of main MOS-FET 3 and turning rectification MOS-FET 51 off before turning-on of main MOS-FET 3, a pulse width elongation circuit 55 for extending on-pulse width of rectification MOS-FET 51, and a main control circuit 8 for producing main drive signals to turn main MOS-FET 3 off and on with operation frequency responsive to on-pulse width of rectification MOS-FET 51 extended by pulse width elongation circuit 55 to vary operation frequency of main MOS-FET 3 so as to restrain noise by high frequency components in main d

Abstract: The present invention is to provide a series resonant converter, which includes a transformer, two power switches connected to primary side of the transformer, a resonant control chip having two control pins connected to gates of the two power switches respectively, a resonant capacitor having one end connected to one end of the primary side and the other end connected to source of one power switch, a resonant inductor having one end connected to the other end of the primary side and the other end connected to a line between the two power switches, and at least one bypass resistor connected in parallel to the resonant capacitor, so as to allow voltage of the resonant capacitor to be rapidly released to ground when the converter is turned off and effectively lower inrush current of the resonant capacitor generated at an instant when the converter is turned on from off.

Abstract: According to one embodiment, in a power supply device, a power conversion circuit which outputs a power supply voltage to a load by converting the power supply voltage into a predetermined output voltage, and control circuit which has a ground potential which is different from that of the power conversion circuit, and controls the power conversion circuit are provided. In addition, a power supply circuit which supplies the power supply voltage to the control circuit by converting the power supply voltage into a control power supply which is insulated with respect to the ground voltage of the power conversion circuit.

Abstract: A power supply for a magnetron has a high voltage converter, a microprocessor and a resistor. The high voltage converter comprises an integrated circuit oscillator, switching transistors, an inductance L1, a transformer and a rectifier. A voltage source supplies an augmented DC voltage to the converter. An operational amplifier, arranged as an error signal magnifier with an integrating capacitor and a resistor, compares a control signal from microprocessor and resistor and supplies an output signal to the oscillator. Oscillator controls switching transistors, the output of which connects to inductance and the primary winding of the transformer. The secondary winding of the transformer is connected to half bridge diodes and capacitors, which provide DC current from the transformer to the magnetron.

Abstract: A device (1) for feeding electrical energy from an energy source with variable source voltage into an electric power supply network (15), said device (1) including a transformer (112) for galvanic isolation, a resonant inverter (11) with semi-conductor switches (a-d; A, B), one or several resonant capacitors (17; 18, 19; 20, 21) and one rectifier (113), is intended to provide high efficiency and have galvanic isolation. This is achieved in that the resonant inverter (11) is operated in the full resonant mode if the operating voltage is in an operation point (MPP) and in the hard-switching mode if the voltages exceed the operation point (MPP).