Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Hideki Omori

Hidekazu Yamashita

Kazuhiko Asada

Haruo Suenaga

Kazuho Sakamoto

Makoto Mihara

Kenji Yasui

Yoshiaki Ishio

Takeshi Kitaizumi

Makoto Kitabatake

Kazuhiro Nobori

Hideyuki Kominami

Masanori Ogawa

Nobuyoshi Nagagata

Kiyoshi Izaki

Hirofumi Noma

Kazuhiko Hashimoto

Yuji Fujii

Shinichi Sakai

Daisuke Bessyo

Hideaki Moriya

Izuo Hirota

Hiroyuki Ogino

Naofumi Nakatani

Takahiro Miyauchi

Takayuki Urata

Hisashi Morikawa

Tadashi Miki

Osamu Eguchi

Shinji Kondoh

Atsushi Fujita

Haruo Terai

Emiko Ishizaki

Kenji Kida

Kenji Hattori

Taizo Ogata

Youji Uetani

Kouji Niiyama

Hiokaki Moriya

Hidetomo Nagata

Masafumi Sadahira

Tetsuo Obata

Kamli Mokhtar

Wataru Uchiyama

Toshiaki Iwai

Daisuke Bessho

Makoto Imai

At least two switching devices each including a substrate formed of a wide bandgap semiconductor, source and gate electrodes formed in a principal surface side of the substrate, and a drain electrode formed on the back surface of the substrate are stacked so that respective upper surface sides of the switching face each other.

Sustaining circuit with bi-directional device

A monitoring system for preventing crime in a home, includes a plurality of terminals for monitoring whether predetermined monitoring points are in a stationary or nonstationary state. Further, the monitoring system includes a central processing device for controlling the setting/canceling of alarm operations of the terminals. The central processing device has a communication unit that receives stationary/nonstationary information from the terminals and transmits predetermined information including commands to the terminals. Each terminal has a communication unit that transmits stationary/nonstationary information to the central processing device and receives the predetermined information from the central processing device. Thus bidirectional communication can be achieved between the central processing device and the terminals. The terminals may include a terminal with an emergency call unit which, in an emergency, calls or notifies another, and a terminal having a notification unit which indicates that a nonstationary state has been accepted by a predetermined point of contact.

Monitoring system

Stacked semiconductor transistors

An induction heating apparatus can heat aluminum pot etc. with pot vibration noise being suppressed. During a turn-on time of second switching device , an energy is accumulated at choke coil , and at the same time a resonant current with a shorter period than the turn-on time of second switching device or a driving time of first switching device is generated at heating coil , so that during turn-off of second switching device , i.e., during on-time of first switching device , the energy accumulated at choke coil is transferred to second smoothing capacitor . And then the output power is supplied from smoothing capacitor to heating coil , thereby reducing the pot vibration noise, which is caused by pulsating current of input voltage.

Induction heating apparatus

It is provided a magnetron drive power supply wherein a series connection body of first and second semiconductor switch elements that can be brought into reverse conduction and a series connection body of first and second diodes are connected in parallel, first and second capacitors are connected in parallel to the first and second diodes, a series circuit of a commercial power supply and a primary winding of a high-voltage transformer is connected between a connection point of the first and second semiconductor switch elements that can be brought into reverse conduction and a connection point of the first and second diodes, and output of a secondary winding of the high-voltage transformer energizes a magnetron through a high-voltage rectification circuit.

Magnetron drive power supply

A high frequency heating apparatus including a circuit for driving a magnetron. A circuit comprises a leakage transformer, a second capacitor connected in series to primary coil of said leakage transformer, a second switching device connected in parallel with a series circuit of said primary coil and second capacitor, a first capacitor connected in parallel with said second switching device, and a first switching device connected in series to said second switching device. Under a structure of the present invention, the switching device and the leakage transformer, both being the key components of the circuit, may respectively be used in common either on a circuit of 200V-240V commercial power supply or on a circuit of 100V-120V commercial power supply. This enables volume production of the key components, which leads to a benefit of reduced cost of the components as well as the cost of heating apparatus.

High frequency heating apparatus

A heating apparatus includes a heating element having a conductor, at least a part of which is an electrically closed circuit along which an eddy current flows; a container for accommodating the heating element; a magnetic field induction section for induction-heating the heating element; and a high frequency power supply device for supplying high frequency power to the magnetic field induction section. The heating element is induction-heated by an AC magnetic field generated by the magnetic field induction section.

Induction heating of heating element

High-frequency inverter and induction cooking device using the same

A switching device is employed in a power supply for driving a magnetron with lower withstand voltage and better controllability. A high frequency heating apparatus comprises a power supply, a leakage transformer connected to the power supply, a first switching device connected in series to a primary coil side of the leakage transformer, a first capacitor, a series circuit of a second capacitor and a second switching device, a driving circuit having an oscillator for driving the first switching device and the second switching device, a rectifier connected to a secondary coil side of the leakage transformer, and a magnetron connected to the rectifier. With this configuration, voltage applied to the first switching device can be clamped, and at the same time, the OFF time can be freely adjustable by the effect of the second capacitor and the second semiconductor switching device.

Switching power supply for high frequency heating apparatus

In a switching device of an induction heating cooker, an oppositely poled diode for conducting a reverse current is coupled across the collector-emitter portion of a switching element provided in the first switching device, and turn-ON operation of the switching devices does not OCCUR in normal operation of the DUTY FACTOR T.sub.2 /T.sub.1 .apprxeq.0.5.

Induction heating cooker operated at a constant oscillation frequency

An induction heating cooker has a rectifier (13) for producing pulsating DC current, an inverter (14) which receives the pulsating current given from the rectifier (13) and produces a high frequency output current and a load circuit (15) including an output coil (21) and a resonance capacitor (22) connected in series to each other to receive high frequency output signal from the inverter, and the variation or adjustment of output electromagnetic power is made by changing duty ratio of the high frequency output current of the inverter by giving variable duty ratio setting signals to switching elements (Qa, Qb) in the inverter 14; the frequency of the high frequency output current of the inverter 14 is fixed, and therefore, unpleasant interference sound is not generated at parallel simultaneous operation.

Induction heating cooker with constant frequency controlled inverter

An induction heating apparatus comprises a heating coil and a transistor which is connected to a direct current power source in series thereto to form an inverter for converting the direct current to an alternating current, and furthermore, a first coupling coil for supplying a forward base current to the transistor is coupled with the heating coil inductively and a second coupling coil for supplying a inverse base current for the transistor is also coupled to the heating coil inductively, and the inverter is controlled by a switching device which is controlled by a control circuit.

Induction heating apparatus using inductive coupling for current

Growing community of inventors

Hyogo, Japan

Hideki Omori