Murata Manufacturing Co., Ltd.

Hajime Shiji

Yoshiyuki Uno

Shouhei Hirose

Takashi Hara

Yoshiaki Mizushima

Masanori Konishi

An abnormality determiner turns OFF a third switch and controls a converter controller to stop operating in a case where a voltage value detected by a voltage detector during a normal mode exceeds a first threshold value. The abnormality determiner determines that a first switch has an abnormality in a case where the voltage value exceeds a second threshold value in a state where the converter controller is stopped. The abnormality determiner controls the converter controller to operate in a case where the voltage value is equal to or smaller than the second threshold value in a state where the converter controller is stopped. The abnormality determiner determines that the converter controller has an abnormality in a case where the voltage value exceeds a third threshold value in a state where the converter controller is operated.

Power supply apparatus

A power supply apparatus includes a converter, an output voltage detector, an output voltage controller that performs control to make a detected value of an output voltage of the power supply apparatus approach a target value in accordance with a comparison result between an output voltage of the converter and a reference voltage, and an instructed value reader that reads an instructed value regarding the output voltage from outside. A pre-bias voltage is applied across output terminals from an external circuit connected to the output terminals also during a time when the converter stops an operation. At a time when the converter starts to operate, the output voltage is set such that the output voltage becomes identical or approximately identical to a pre-bias voltage. After the output voltage has become identical or approximately identical to the pre-bias voltage, the output voltage is set such that the output voltage becomes an instructed voltage instructed from outside.

In a switching power-supply apparatus that controls magnitudes of output voltages of respective converters connected in parallel to be equal to a target voltage value, only a selected one of the converters is made to operate. In this state, correction values generated by the respective converters are received and stored in memory. Droop characteristics generated for the respective converters are corrected using the correction values. Accordingly, a switching power-supply apparatus and a droop characteristic correction method capable of correcting variations in droop characteristics generated for respective power converters are provided.

Switching power-supply apparatus and droop characteristic correction method

A switching power supply device equipped with an inverter device includes a transformer including a primary winding and a secondary winding, which are magnetically coupled with each other. On the primary side, a capacitor and a switching element are connected in series with the primary winding and a switching element is connected in series the switching element and is connected in parallel with the primary winding and the capacitor. On the secondary side, a bidirectional switching element, which includes FETs, is connected in series with the secondary winding. A control circuit alternately turns the first switching element and the second switching element on, and turns the bidirectional switching element on in an off period of the first switching element or the second switching element. Thus, the inverter device outputs an alternating current output voltage by using a single secondary winding of a transformer.

Inverter device

A resonant converter circuit generates an output voltage from an input voltage by switching first and second FETs. A subsequent-stage switching control circuit alternately subjects the first and second FETs in the resonant converter circuit to on/off control with a fixed on-duty ratio and a fixed switching frequency. A boost converter circuit includes an inductor, a smoothing capacitor, and a third FET arranged to switch the energization of the inductor. A previous-stage switching control circuit subjects the third FET in the boost converter circuit to on/off control with a controlled on-duty ratio, and adjusts an output voltage to the resonant converter circuit.

Switching power-supply device

A switching power supply includes a series resonant circuit that includes a resonant inductor and a resonant capacitor connected in series with a primary winding of a converter transformer. By controlling turning on and off of first and second switching elements in a complementary manner, current is supplied to the series resonant circuit. A third switching element connected on the secondary side of the converter transformer is synchronized with the first switching element, and a fourth switching element is synchronized with the second switching element. If a switching frequency is less than a resonant frequency, turning on of the third and fourth switching elements is synchronized with turning on of the first and second switching elements, and turning off of the third and fourth switching elements is controlled, without being synchronized with turning off of the first and second switching elements, after half a resonant period has elapsed.

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Nagaokakyo, Japan

Hajime Shiji