Panasonic Corporation

Panasonic Holdings Corporation

Satoshi Wada

Takuya Ishii

Kazuhito Kimura

Takashi Ryu

Mikio Motomori

Junichi Morita

Yoshihisa Minami

Makoto Ishimaru

Masaaki Koto

Ikuo Ozaki

Yoichi Deguchi

Rumi Nakai

Tomoyuki Hatakeyama

An insulator () includes: an annular outer peripheral portion (); and a wound portion () which extends in a first direction that is a direction from the outer peripheral portion () toward a center of the outer peripheral portion and around which a wire () is wound. The wound portion () includes: an introduction portion () to which the wire () is introduced from the outer peripheral portion (); an extend-around portion () around which the wire () introduced from the introduction portion () extends; and an isolation wall () which is located between the introduction portion () and the extend-around portion () in the first direction and by which an introduced portion of the wire () which is introduced at the introduction portion () and a first-turn portion of the wire () which is wound around the extend-around portion () are isolated from each other.

Insulator, electric motor, and applied equipment

A current sense circuit for use with a switching regulator including a first transistor, connected to an inductor, configured to switch a current flowing through the inductor from a power supply; and a second transistor, connected to a node to which the inductor and the first transistor are connected, configured to be turned on during a part of an OFF period of the first transistor. The current sense circuit includes a current generator configured to generate a sense current corresponding to a current flowing through the first transistor; a hold circuit configured to output a voltage corresponding to the sense current during an ON period of the first transistor, and to hold and output the voltage corresponding to the sense current during the OFF period of the first transistor; and an output transistor configured to generate a current corresponding to the voltage output by the hold circuit.

Current sense circuit and switching regulator using the same

A power supply device includes an inductor controlled by switching to be charged or discharged such that a DC input voltage is boosted and a capacitor which smoothes the boosted voltage to generate a DC output voltage. Specifically, the power supply device further includes a transistor connected between the inductor and the capacitor to carry out a rectification function; an output voltage determination circuit which refers to the DC input voltage and the DC output voltage to determine the level of these voltages; and a current control circuit which controls a current flowing through the transistor such that the current has a predetermined value when the output voltage determination circuit determines that the DC output voltage is lower than the DC input voltage.

Power supply device

The present invention provides a current-mode control step-up converter capable of reducing the minimum duty ratio to a sufficiently small value and facilitating the setting of the maximum duty ratio. The step-up converter comprises a current detectorfor generating a current detection signal Vc corresponding to the current of a rectifier; an error amplifierfor generating an error signal Ve corresponding to an output DC voltage Vo; and a control circuitfor turning ON/OFF the main switchon the basis of the current detection signal Vc and the error signal Ve. The control circuitcomprises a comparatorand a timer circuit. With this configuration, the ON time of the main switchis set at a predetermined value, and the valley value of an inductor current changing in a triangular waveform is controlled. Hence, the OFF time of the main switch is adjusted to stabilize the output. Since the ON time of the main switchcan be set as desired, the minimum duty ratio can be reduced to zero or a sufficiently small value.

Step-up converter

A step-up power supply device includes: a step-up converter; a startup circuit which controls the on/off operation of a switch element of the step-up converter when an output voltage of the device is smaller than a reference voltage; and a control circuit which operates in substitution for the startup circuit when the output voltage is higher than the reference voltage to control the on/off operation of the switch element such that the output voltage reaches a target value. The startup circuit includes an oscillation circuit for generating a pulse signal which has a predetermined on/off ratio, a current comparison circuit for comparing a current of the switch element with a predetermined restriction value, and a drive circuit for generating a drive signal based on which the switch element is turned on/off, the drive signal being generated from the pulse signal to turn on the switch element, and the drive signal being generated from the output of the current comparison circuit or the pulse signal to turn off the switch element.

Step-up power supply device

Growing community of inventors

Osaka, Japan

Satoshi Wada