Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Panasonic Electric Works Co., Ltd.

Hiroyuki Nishino

Eiji Shiohama

Minoru Maehara

Kazunori Kidera

Shigeaki Yamasaki

Kazuo Itoh

Hiroaki Koshin

Yosuke Kondo

Teruhito Takeda

Shojiro Kido

Hiromichi Goto

Masao Kamada

Mariko Nishi

Yosiaki Hasitani

Hideki Tamura

Takuya Kagawa

Yukihiro Murata

Kouichi Teraura

Yasuhisa Ihira

A visible light communication apparatus includes: an on/off switch connected in series to a load circuit including a light emitting diode; an impedance circuit connected in series to the on/off switch; a feedback circuit that feeds back an error between a voltage drop across the impedance circuit and a reference voltage potential to a voltage source as a feedback signal; a drive circuit that turns on and off the on/off switch in accordance with a communication signal which is a binary signal; an isolation circuit that transmits power while being electrically isolated; and an auxiliary power supply circuit that is connected between two output terminals of the voltage source, generates an auxiliary supply voltage, and supplies power based on the auxiliary supply voltage generated to the on/off switch and the drive circuit via the isolation circuit.

Visible light communication apparatus

An illumination light communication apparatus includes: a light source which emits illumination light; a power supply circuit for supplying constant current to the light source; a switch which is connected in series to the light source, and intermittently interrupts current which flows through the light source; a signal generating circuit which generates a binary communication signal which controls on and off of the switch to modulate the illumination light; and a current limiting circuit which is connected in series to the light source and the switch, and limits the current which flows through the light source to prevent the current from exceeding a current set value which is variable.

Illumination light communication apparatus and communication module

An illuminating light communication device comprises a constant current source, a smoothing capacitor connected to an output of the constant current source, a load circuit comprising a light emitting diode and connected to the output of the constant current source, a load change element added to the load circuit and thereby partially changing load characteristic of the load circuit, and a switch element configured to determine whether or not the load change element is added to the load circuit in accordance with a binary optical communication signal.

Illuminating light communication device

A DC power supply system includes a DC power supply and a secondary battery for backing up the DC power supply. When a voltage of the DC power supply is lower than a voltage of the secondary battery, the DC power system adds an extra voltage to the voltage of the DC power supply to provide an input voltage to the secondary battery higher than the voltage of the secondary battery by using an electric power of the secondary battery, and the secondary battery is charged.

DC power supply system

An electric power supply apparatus, which enables a driving frequency of a switching circuit connected to a primary side of a transformer constant and output of a secondary side variable, comprises a transformer (), a series circuit of two first switching elements (Q, Q) connected between terminals of a direct current power supply (), an LC resonant circuit connected between both ends of one of the first switch element (Q) and a primary winding (Np) of the transformer (), bidirectional switch elements (Q, Q) connected to secondary windings (Ns, Ns) of the transformer () and having a rectification function and a phase control function, and a control circuit for inputting gate driving signals having a phase difference into the first switch elements (Q, Q) and the second switch elements (Q, Q).

Electric power supply apparatus

A power supply device includes a transformer; a series circuit of two bidirectional switching elements connected between terminals of the commercial power supply and having a rectification function and a switching function; an LC resonant circuit connected between a primary coil of the transformer and both ends of one of the bidirectional switching elements; a rectifying element connected to a secondary coil of the transformer; and a control circuit for inputting a gate driving signal to the bidirectional switching elements. The power supply device performs synchronous rectification from the bidirectional switching elements.

Power supply device for converting AC power from a commercial power supply into DC power

An illumination light communication device includes a power supply unit controlling a load current in a light source unit to be maintained constant based on a dimming signal; an impedance unit series connected to the light source unit; a switch element parallel connected to the impedance unit to connect/disconnect the impedance unit with the light source unit; and a control unit controlling on/off of the switch element to modulate a light intensity of the light source unit such that a binary communication signal is superimposed on illumination light therefrom. The control unit controls the impedance of the impedance unit such that a difference between magnitudes of the load currents respectively when the pulse of the communication signal is superimposed and is not superimposed is maintained constant regardless of a dimming rate of the dimming signal in a range of a dimming rate equal to or greater than a predetermined level.

Illumination light communication device, and illumination apparatus and system including same

Disclosed is a bidirectional DC/DC converter including: a primary side circuit that includes a first DC power source or a first load; a secondary side circuit that includes a second load or a second DC power source; and a power transfer unit that is capable of transferring power bi-directionally between the primary side circuit and the secondary side circuit. Further, the bidirectional DC/DC converter includes a control circuit that controls the primary side circuit and secondary side circuit in such a way that current flows through the power transfer unit from the first DC power source to the second load or from the second DC power source to the first load.

Bidirectional DC/DC converter with simple control operation

An illumination light communication device includes a light source unit including light emitting elements; a power supply unit controlling a load current flowing through the light source unit to be maintained at a constant; a switch element connected in series to the light source unit; and a control unit configured to control on/off of the switch element to modulate a light intensity of illumination light from the light source unit such that a binary communication signal is superimposed on the illumination light. The control unit has a switching circuit to open/close a path between the light source unit and the power supply unit, controls on/off of the switching circuit based on a dimming signal to perform a dimming control on the light source unit by a PWM control, and allows the communication signal to be superimposed on the illumination light in synchronization with an ON time of the switching circuit.

In an insulation type AC-dc converter in which input current from a commercial power supply is converted to obtain insulated direct current, the overall efficiency is raised and the structure is simplified. A multi-resonance type half-bridge DC-DC converter having an insulation transformer T is used as a first converter, and a boosting chopper circuit for power factor improvement is used as a second converter. Hence through multi-resonance operation, increases in losses can be suppressed even when the switching frequency is raised, and because a half-bridge circuit is used, switching elements and similar with lower voltage ratings can be employed, whereby overall efficiency can be increased. Moreover, a voltage substantially similar to the full-wave rectified waveform of the power supply voltage is obtained from the output capacitor at the boosting chopper circuit input, whereby there is no need for a feed-forward circuit across the insulation transformer, and moreover the electrolytic capacitor which had to be provided on the converter input side is unnecessary. This is advantageous for achieving miniaturization and a thin design.

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Osaka, Japan

Hiroyuki Nishino