Abstract: A control method for a switching power supply circuit, the control method causing a processor to execute a process, the process includes: calculating a differential value between an output voltage of the switching power supply circuit and a target voltage; multiplying the differential value by a first coefficient to calculate a correction value; correcting a first detection value of an output current of the switching power supply circuit, which is detected by a current transformer circuit, based on the correction value, to generate a second detection value; comparing the second detection value with a threshold current value to determine whether or not an overcurrent has occurred; and reducing, when it is determined that the overcurrent has occurred, the output voltage of the switching power supply circuit.

Abstract: A double-ended forward converter includes: a first switching element and a second switching element that are coupled to a primary side of a transformer; a pulse generation circuit that generates a pulse signal for controlling the first and second switching elements; an isolation transformer that converts the pulse signal into an alternating-current signal; a rectifier circuit that rectifies the alternating-current signal and generate gate voltages of the first and second switching elements; a driver circuit that includes a third switching element which drives gates of the first and second switching elements, a voltage generated on a secondary side of the isolation transformer being input to a gate of the third switching element; and a minus bias generation circuit that generates a source voltage of the third switching, based on a change in the voltage generated on the secondary side of the isolation transformer.

Abstract: A power supply apparatus includes a DC-DC converter configured to convert an input voltage into an output voltage in accordance with a duty cycle which is decided by a difference of a third signal, a first photo coupler configured to output a first signal corresponding to the output voltage, a converter configured to convert the output voltage into a digital signal, and a second photo coupler configured to output a second signal corresponding to the digital signal, a memory, and a processor coupled to the memory and configured to calculate a third signal on the basis of the difference between the first signal and the second signal, and control the DC-DC converter so that the third signal is to be zero.

Abstract: An inductor apparatus includes: a substrate including an electrical insulation property and a non-magnetic material; and a plurality of inductors disposed in the substrate so as to extend from a first surface of the substrate to a second surface of the substrate, each of the plurality of inductors including: an inductor conductive part that has an electrical conductivity and extends in a thickness direction of the substrate; and a magnetic layer that covers a side of the inductor conductive part and include a relative permeability and a soft magnetic material.

Abstract: A control device includes a processor that executes a process including generating a driving signal that drives a switching device, so that an output voltage of a converter circuit that performs a step-down conversion on input power by driving the switching device matches a target value, and modifying the target value so that as an output current of the converter circuit becomes lower the output voltage becomes closer to an upper limit value of the output voltage.

Abstract: A capacitor life diagnosis apparatus includes ringing detection circuitry that detects ringing of an output voltage of a power source including a capacitor at an output end, and signal generation circuitry that generates a signal indicating a life of the capacitor based on the ringing detected by the ringing detection circuitry.

Abstract: A semiconductor device includes: a first field-effect transistor configured to have a source connected to a reference potential node; a second field-effect transistor configured to have a source connected to a drain of the first field-effect transistor, and a gate connected to the source of the first field-effect transistor; a gate signal node configured to input a gate signal therein; a first resistor configured to be connected between the gate signal node and a gate of the first field-effect transistor; and a first capacitor and a switch circuit configured to be connected between a drain of the second field-effect transistor and the gate of the first field-effect transistor, in which the switch circuit is connected in series with the first capacitor.

Abstract: A power supply apparatus includes a trans circuit configured to convert an input voltage into an output voltage by adjusting switching of the input voltage; an output voltage detector configured to detect the output voltage; a compensator configured to generate a control value controlling a duty ratio of the switching such that a value of the detected output voltage coincides with a target value for the output voltage; an input voltage detector configured to detect the input voltage; an estimator configured to estimate an allowed range of the control value in accordance with the target value and a value of the detected input voltage; and an adjuster configured to adjust the control value so as to stop the switching when the control value falls outside the allowed range.

Abstract: An electronic apparatus includes a housing; a substrate disposed on the inner side of the housing; a plurality of temperature sensors disposed on the substrate; and a processor. The processor performs a procedure including calculating heat source temperatures of a plurality of heat sources disposed on the substrate from temperatures measured by the temperature sensors by using a first heat transfer model not including a first parameter representing a transient response of heat transfer from the heat sources to the temperature sensors; and calculating a surface temperature of a surface of the housing from the heat source temperatures by using a second heat transfer model including the first parameter and a second parameter representing a transient response of heat transfer from the heat sources to the surface.

Abstract: A power supply device includes: a memory; and a processor coupled to the memory and the processor configured to: determine a duty ratio of a control signal of a switching element in a power supply circuit so that an output voltage of the power supply circuit approaches a target voltage; compute an acceptable range of a duty ratio based on an output current of the power supply circuit detected by a current detecting circuit; output the duty ratio when the duty ratio is inside the acceptable range; and stop the power supply circuit when the duty ratio is outside the acceptable range.

Abstract: A control method for a switching power supply circuit, the control method causing a processor to execute a process, the process includes: calculating a differential value between an output voltage of the switching power supply circuit and a target voltage; multiplying the differential value by a first coefficient to calculate a correction value; correcting a first detection value of an output current of the switching power supply circuit, which is detected by a current transformer circuit, based on the correction value, to generate a second detection value; comparing the second detection value with a threshold current value to determine whether or not an overcurrent has occurred; and reducing, when it is determined that the overcurrent has occurred, the output voltage of the switching power supply circuit.

Abstract: A PFC circuit generates substantially sinusoidal current that is in-phase with AC input voltage to compensate for a power factor. A DC-DC converter converts the voltage of a signal outputted from the PFC circuit to determined voltage. A current change detection section detects an amount of change in current outputted from the DC-DC converter, compares the detected amount of change in current with a threshold set in advance, and if the detected amount of change in current is larger than the threshold, outputs a gain switching signal for raising the gain of voltage outputted from the PFC circuit. The current change detection section outputs a voltage control signal for raising the voltage outputted from the PFC circuit to a determined value. A voltage setting section sets the voltage outputted from the PFC circuit to the determined value on the basis of the voltage control signal.

Abstract: A synchronous rectification converter includes: a first switching element coupled between a inductor and an input terminal; a second switching element coupled between the inductor and the input terminal; a capacitive element coupled between the other end of the inductor and the other end of the input terminal; a control circuit detects voltages of the inductor and the capacitive element; a current inversion detection circuit detects inversion of a direction in which a current supplied from the second switching element to the inductor flows and outputs an inversion signal; a delay circuit delays the inversion signal and outputs a delay inversion signal; a synchronous rectification reset circuit that changes the control signal; a load detector detects reduction of an output current supplied from a connection node of the inductor and the capacitive element; and a delay control circuit generates a delay control signal.

Abstract: First FET switches control supply of electricity from an external power supply to a primary winding of a transformer. A condenser is connected, in series, to a secondary winding of the transformer. A second FET switch is connected, in parallel, to the secondary winding and the condenser. The diode is connected, in parallel, to the second FET switch. A switch control unit acquires a value obtained by measuring a current flowing through the first FET switches and the second FET switch and controls, on the basis of the measurement result of the current, conduction of the first FET switches and the second FET switch.

Abstract: A capacitor life diagnosis device includes: a first fluctuation detecting unit configured to detect a maximum value of fluctuation in output voltage of a first capacitor every fixed time; and an output unit configured to predict a residual life of the first capacitor on the basis of temporal transition of the maximum value of fluctuation in the output voltage detected by the first fluctuation detecting unit, and output a signal indicating the residual life of the first capacitor.

Abstract: A planar type transformer includes: a multilayer substrate including a primary main winding pattern and a secondary main winding pattern that perform first power transmission, the primary main winding pattern and the secondary main winding pattern being stacked with an insulating layer interposed between the primary main winding pattern and the secondary main winding pattern; and an auxiliary winding that is disposed outside the multilayer substrate and performs second power transmission between the auxiliary winding and the primary main winding pattern or the secondary main winding pattern.

Abstract: A power supply apparatus includes a power supply section and a control section. The power supply section includes a first switch which performs switching of power-supply output, an inductor and a capacitor which form an LC circuit that resonates current flowing through the first switch, and a second switch which changes capacitance of the capacitor. The control section finds in advance a correspondence between a time ratio of a switching pulse of the first switch and a resonance frequency which matches an edge of a switching pulse having each time ratio, and controls switching of the second switch so as to resonate the LC circuit at a resonance frequency corresponding to a time ratio at operation time.

Abstract: A DC-DC converter includes a capacitor configured to be charged for a predetermined period by an external voltage, an inductor configured to constitute an LC resonance circuit together with the capacitor, a closed-loop current path configured to release energy accumulated in the capacitor after the predetermined period to cause a current flowing in the LC resonance circuit to oscillate, a transformer configured to receive a current flowing in the closed-loop current path, and a rectifying circuit situated on an output side of the transformer.

Abstract: A control device includes: a power supply circuit that controls output voltage using a switching element; a generation unit that generates a reference signal on the basis of the output voltage from the power supply circuit; a PWM unit that generates a PWM signal that is output to the switching element by comparing the reference signal with a carrier signal; and a switching unit that switches a frequency of the carrier signal by changing amplitude of the carrier signal, wherein the generation unit generates the reference signal on the basis of the frequency.

Abstract: A processor disposed over a substrate of an electronic apparatus acquires a first measured value from a temperature sensor disposed on the substrate, and calculates surface temperature of a surface of an enclosure of the electronic apparatus on the basis of a transfer function G(s) based on a first thermal resistance and a first thermal capacitance between a heat source over the substrate and the surface of the enclosure, a transfer function H(s) based on a second thermal resistance and a second thermal capacitance between the heat source and the temperature sensor, and the first measured value.