Abstract: A direct current/alternating current (DC/AC) inverter system includes a primary DC-DC converter that receives an input DC voltage and a secondary DC/AC inverter. The primary DC-DC converter includes a plurality of switching networks and a plurality of transformers having a plurality of primary windings and a plurality of secondary windings. Characteristically, the plurality of secondary windings is arranged in series to provide a first output and a second output. A resonant LC circuit is connected in series with the first output and the second output. A rectifier rectifies an AC voltage between the first output and the second output to form a first rectified output. The secondary DC/AC inverter receives the first rectified output or filtered output thereof and provides a high voltage AC output. A controller mediates switching of the plurality of switching networks.

Abstract: A charging pad for charging one or more receiver devices is disclosed. The charging pad includes at least one first resonator coil operable at a first frequency band and at least one second resonator coil operable at a second frequency band. Further, the charging pad includes at least one exciter coil magnetically coupled to the at least one first resonator coil and the at least one second resonator coil. In addition, the charging pad includes an excitation unit operationally coupled to the at least one exciter coil and configured to drive the at least one first resonator coil and the at least one second resonator coil via the at least one exciter coil.

Abstract: An inverter and an over current protection method thereof are provided. The inverter includes an inverting circuit, a filtering capacitor and an over current protection circuit. The inverting circuit is configured to convert a DC input voltage into an AC output voltage and provide the AC output voltage to a load. The filtering capacitor is coupled to the inverting circuit and the load in parallel. The over current protection circuit is coupled to the inverting circuit and the filtering capacitor and configured to provide an over current protection mechanism. The over current protection circuit detects an AC current on the filtering capacitor and determines whether to enable the over current protection mechanism according to the AC current in order to restrain the power conversion operation of the inverting circuit.

Abstract: An energy recovery snubber circuit for use in switching power converters. The power converters may include a switch network coupled to a primary winding of an isolation transformer, and rectification circuitry coupled to a secondary winding of the isolation transformer. The energy recovery snubber circuit may include clamping circuitry that is operative to clamp voltage spikes and/or ringing at the rectification circuitry. The clamped voltages may be captured by an energy capture module, such as a capacitor. Further, the energy recovery snubber circuitry may include control circuitry operative to return the energy captured by the energy capture module to the input of the power converter. To maintain electrical isolation between a primary side and a secondary side of the isolation transformer, a second isolation transformer may be provided to return the captured energy back to the input of the power converter.

Abstract: A resonant conversion system is provided, in which a resonant converter receives an input voltage to generate an output voltage, and a buck converter provides the input voltage of the resonant converter, and controls the input voltage to perform an over-current protection process.

Abstract: Power supplies, power adapters, and related methods are disclosed. One example power supply includes an open loop DC to DC converter having an input for connecting to an input power source and an output for supplying a DC output voltage or current and an enable/disable circuit coupled to the open loop DC to DC converter. The enable/disable circuit is configured to enable and disable the open loop DC to DC converter as a function of the DC output voltage or current. One example method includes determining a DC output voltage or current from an open loop DC to DC converter and enabling and disabling the open loop DC to DC converter as a function of the determined DC output voltage or current.

Abstract: According to the invention, a blocking oscillator type converter circuit functions with a transformator that only comprises a primary winding and a secondary winding. Said transformator does not comprise a return coupling winding for the blocking oscillator. The control voltage of the oscillator is derived from the primary voltage of the transformator during the free-wheeling phase. The invention also relates to a voltage monitoring circuit that works independently from the oscillator, the output voltage of the oscillator being repressed when the voltage on the output of the blocking oscillator is too high. A flow monitoring circuit functions independently from the oscillator and the voltage monitoring circuit and suppresses the impulses for the power transistor when the power on the output side exceeds a predetermined measurement.

Abstract: A power supply circuit includes a control circuit which outputs a control signal when an in-rush current flows and a power-supply-resistance control circuit which supplies a current to a capacitive load. The power-supply-resistance control circuit, provided in the current path between a power supply and the capacitive load, increases the resistance of the current path in response to the control signal and reduces the resistance of the current path in response to a stop page of the control signal, whereby the control signal is output or stopped so that the in-rush current is suppressed to a value smaller than or equal to a given value.

Abstract: A DC-AC converter for converting DC voltage to AC voltage. The converter includes a conversion circuit for converting DC voltage to voltage having a polarity corresponding to AC voltage. A filter circuit receives the converted voltage, smoothes the converted voltage, and outputs the smoothed voltage as AC voltage. A first switch operably connects the voltage conversion circuit and filter circuit. A second switch is arranged between input terminals of the filter circuit. An output current detection circuit detects overcurrent that is greater than a predetermined first threshold. When overcurrent that is greater than the first threshold is detected, the protection circuit stops the supply of power in the voltage conversion circuit, deactivates the first switch, and activates the second switch.

Abstract: A circuit arrangement for protecting an electronic converter against overloads includes: a low impedance path selectively activatable to prevent ignition of the electronic converter, the low impedance path including an electronic switch, a control capacitor whose charge voltage controls the electronic switch, whereby the electronic switch is activated to prevent ignition of the electronic converter when the charge voltage of the control capacitor is above a given threshold, a first generator for loading the control capacitor, the first generator activatable in the presence of a first overload condition of the electronic converter, and a second generator for further loading the control capacitor, the second generator activatable in the presence of a second overload condition of the electronic converter, the second overload condition being heavier than the first overload condition.

Abstract: An inverter power supply system includes a half-bridge inverter circuit which includes a first switching element, a second switching element, a first auxiliary capacitor and a second auxiliary capacitor for converting a DC voltage from a DC power supply circuit to an AC voltage. An output control circuit outputs a first output control signal and a second output control signal with a phase difference of a half cycle to control the inverter circuit. An inverter driving circuit turns on the first (or second) switching element when the first (or second) output control signal turns ON while turning off the first (or second) switching element upon lapse of a first (or second) delay time for allowing the first (or second) auxiliary capacitor to discharge to a predetermined level after the first (or second) output control signal turns OFF.

Abstract: There are disclosed a synchronous rectifying type of DC—DC converter, a DC—DC converter control circuit constituting such a type of DC—DC converter, a monitor circuit for monitoring an operation of a DC—DC converter, and an electronic equipment having a DC—DC converter, considering a conduction current. A DC—DC converter has a main switch and a synchronous rectifying switch, in which said main switch and said synchronous rectifying switch are alternately turned on so that a voltage of a DC electric power is transformed and outputted. A state that said main switch and said synchronous rectifying switch are simultaneously turned on is detected.

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: AC to DC inverters that are formed from electronic switches, such as MOSFETs, that are controlled by gating pulses obtained from comparators. The comparators compare a varying signal against two closely spaced reference voltages so as to provide gating pulses with delays needed to prevent shoot-through in the electronic switches.

Abstract: A high-voltage power source apparatus with a simple construction which outputs a voltage by overlapping a DC voltage with an AC voltage. An alternating current (AC) voltage generator generates an AC voltage and outputs the AC voltage to a secondary coil of a transformer. The AC voltage and the DC voltage are developed and simultaneously overlapped from a common secondary coil of the transformer. Thus, separate AC and DC voltage generators are not necessary to produce the overlapped voltage, simplifying construction. The DC portion of the overlapped voltage may be regulated by feeding back a sample of the output voltage to a control circuit which compares the feedback with a reference and regulates the DC portion accordingly. A plurality of the overlapped voltage circuits may be operated in parallel from a single secondary coil of the transformer.

Abstract: A power supply apparatus includes a variable frequency oscillating circuit, a driver, a soft start circuit, switching elements for receiving a switching signal, a resonating capacitor connected at a connection point of the switching elements via a primary coil of a transformer, a rectifying circuit provided at a secondary coil of the transformer, an amplifier for comparing an output voltage, Vb obtained at the rectifying circuit and a reference voltage, Vref, a photo-coupler for controlling an impedance of an oscillating element of a variable frequency oscillating circuit based on the comparison output, and a charge voltage control circuit for controlling an oscillation frequency when the variable oscillation circuit is initially driven. A frequency control signal when power is ON is made nonlinear relative to time. As a result, a change in oscillation frequency immediately after power is ON is made gentle, and a rapid change in current that flows in a primary coil is eliminated.