Yazaki Corporation

Keisuke Kanda

Shota Yoshimitsu

Satoshi Ito

Michito Enomoto

Shingo Suzuki

Koichi Ushitani

A voltage conversion device of the present disclosure includes: an HV-48V DC/DC converter that steps down a high voltage input from a high-voltage battery to 48 V; a first wire harness that supplies 48 V from the HV-48V DC/DC converter to a 48V load; an HV-12V DC/DC converter that steps down the high voltage input from the high-voltage battery to 12 V; a second wire harness that supplies 12 V from the HV-12V DC/DC converter to a 12V load; a 48V-12V DC/DC converter that is connected to the first wire harness and the second wire harness, steps down 48 V to 12 V, and steps up 12 V to 48 V; and a control device.

Voltage conversion device, and control device for voltage conversion device

An active snubber circuit is connected to a buck converter and decreases a first surge voltage and a second surge voltage generated by the buck converter. The active snubber circuit includes a first FET switch connected to the output point of the first surge voltage and a first power storage element, a second FET switch connected to the output point of the second surge voltage and a second power storage element, an inductor connected to a connection point positioned on an output side with respect to the output point of the second surge voltage, the first and second FET switches, and an element connected to the first and second FET switches, the inductor, and ground and through which a forward current flows.

Active snubber circuit and buck converter

A power-supply control device capable of reducing a size of a power-supply device including a main power-supply and a plurality of auxiliary power-supply systems and stably supplying electric power to the plurality of auxiliary power-supply systems is provided. The power-supply control device includes a DC/DC converter that steps down a power-supply voltage from a main battery and outputs the stepped-down power-supply voltage to a first auxiliary power-supply system and a second auxiliary power-supply system; and a controller that stops supply of electric power from the DC/DC converter to the second auxiliary power-supply system when a load of a heater is in a predetermined high-load state, and supplies electric power from the DC/DC converter to the second auxiliary power-supply system when the load of the heater changes from the predetermined high-load state to a predetermined low-load state.

Power-supply control device

The vehicle power supply system includes the DC/DC converter that is disposed on an electric path between the first load related to vehicle control and the battery and converts a voltage of direct current power supplied from the battery to the first load, and the detection device that detects the voltage of the battery. In a case where the engine is restarted by using the starter from the automatically stopped state of the engine, the detection device controls the DC/DC converter to start in a case where the voltage of the battery becomes equal to or less than a threshold value during a period from stoppage of the alternator to start of the starter.

Vehicle power supply system

A multi-output power supply device includes an inductor, a first output terminal, a second output terminal, an FET, an FET, a chopper circuit, and a controller. The FET adjusts a current output from the inductor to the first output terminal. The FET adjusts a current output from the inductor to the second output terminal. The chopper circuit has the FET and the inductor. The FET is connected in parallel with the FET, and conducts or cuts off a current. The inductor is provided between the FET and the second output terminal. For example, the controller lowers a potential from the first output terminal by turning on the FET and sets a potential difference between a drain terminal and a source terminal of the FET to zero to suppress a switching loss when the FET is turned on.

Power supply device

In the power supply device, the insulated transformer transforms the voltage of alternating-current power. The rectifying circuit rectifies the alternating-current power transformed by the transformer to direct-current power. The smoothing inductor smoothes the direct-current power rectified by the rectifying circuit. The first output terminal outputs the direct-current power smoothed by the smoothing inductor. The second output terminal is a terminal different from the first output terminal and outputs the direct-current power smoothed by the smoothing inductor. An FET is provided between the smoothing inductor and the first output terminal and adjusts a current output from the smoothing inductor to the first output terminal. An FET is provided between the smoothing inductor and the second output terminal and adjusts a current output from the smoothing inductor to the second output terminal. The controller controls the FET and the FET.

Power supply device with a controller that controls a first switching element and a second switching element

In a DC/DC converter, when stepping up voltage from an input unit to an output unit or when stepping down voltage from the output unit to the input unit, a second driver IC outputs to a charge pump circuit a control signal for controlling a switching element so as to alternately repeat ON/OFF when a switching element is ON and a switching element is OFF. When stepping up voltage from the output unit to the input unit or when stepping down voltage from the input unit to the output unit, a first driver IC outputs to the charge pump circuit a control signal for controlling the switching element so as to alternately repeat ON/OFF when a switching element is ON and the switching element is OFF. As a result, the DC/DC converter can drive the charge pump circuit without providing an oscillation circuit.

Growing community of inventors

Shizuoka, Japan

Keisuke Kanda