Sansha Electric Manufacturing Company, Limited

Matsushita Electric Industrial Co., Ltd.

Kawasaki Jukogyo Kabushiki Kaisha

Suntory Limited

Takuma Co., Ltd.

Digital Electronics Corporation

Takeshi Morimoto

Hideo Ishii

Kenzo Danjo

Tetsuro Ikeda

Masao Katooka

Kunio Sekimoto

Yuji Ikejiri

Masayuki Ono

Yuta Yoshimatsu

Goro Fujiwara

Mitsunobu Masuda

Hiroaki Kagaya

Takeshi Saeki

Shinichi Kunisaki

Takafumi Okamoto

Seigo Asada

Toru Yamashita

Katsuya Ihara

Kazunori Nakata

Hiroshi Saso

Hiroshi Sasou

Kiyoshi Hirai

A main unitand a subsidiary unitinclude two invertersand, and PWM control circuits, respectively. A changeover switchoperates to simultaneously connect the inputs of the two inverters of the main unitand the inputs of the two inverters of the subsidiary unitin series or in parallel. An imbalance detecting circuitdetects imbalance in the input voltages to the two inverters of the main unit, and provides the detection result to the PWM control circuitsand. The PWM control circuitcontrols the invertersandof the main unitin accordance with the detection result supplied from the imbalance detecting circuit, and the PWM control circuitcontrols the subsidiary unitin accordance with the detection result supplied from the imbalance detecting circuit. The input current to the main unitis larger than the input current to the subsidiary unit

Power supply apparatus

A brake control device of a railcar includes: a brake switching portion configured to perform switching from an operation of an electric brake device to an operation of a mechanical brake device when a switching monitoring speed obtained from a wheelset speed becomes less than a switching threshold; and an adhesion control portion configured to, when the brake switching portion performs the switching, control at least one of the electric brake device and the brake switching portion to cause a wheel to adhere to a rail.

Brake control device of railcar

An arc welding apparatus includes: a switching device connected to both terminals of a secondary winding of a transformer whose opposite primary winding serves as a smoothing reactor on an inverter's secondary side; an output voltage detector detecting an output voltage between a welding wire and a workpiece; and a control circuit controlling the switching device and a circuit on the inverter's primary side. The control circuit includes: a first control portion that turns off the circuit on the inverter's primary side and turns on the switching device when the output voltage detected by the output voltage detector rises to a first predetermined voltage; and a second control portion that turns on the circuit on the inverter's primary side and turns off the switching device after a lapse of a predetermined time after the switching device is turned on.

Arc welding apparatus

A welding machine power supply apparatus outputs welding current in accordance with welding conditions set through operation of a display and setting unit (). When a welding operation is ended while the welding machine power supply apparatus is operating, the welding conditions effective at the time the welding operation is ended are automatically stored in a memory (). When any ones or more of the welding conditions at the time when the welding operation is resumed by the use of the welding machine power supply apparatus are different from the one or ones which were effective when the welding operation was ended, a load button (), a rotary encoder () and a set button () are operated to cause a control unit () to read out the welding conditions stored in the memory () which were effective when the welding operation was ended, and to set the read-out welding conditions in the welding machine power supply apparatus.

Power supply apparatus for welding machine

A programmable display device main body includes an address file detecting section for detecting whether a memory card stores a MAC address file, a password file detecting section for detecting whether the memory card stores a password file, and an activation control section for reading data from the memory card. The activation control section does not read data in a case where the memory card stores neither a MAC address file nor a password file.

Programmable display device

A welder power supply apparatus () includes an inverter (), which is driven intermittently when an electrode () and a workpiece () are separated from each other and no arc is being generated between them, whereby power loss generated in the inverter () when the inverter () is driven in the non-load state of the power supply apparatus and power loss caused by exciting current flowing through an transformer () disposed in the output of the inverter () can be reduced. The inverter () is driven continuously when output current (Io) becomes higher than a threshold value (Ib) after the electrode () and the workpiece () are brought into contact with each other for starting arcing between them. In this manner, the arcing can be initiated without fail.

Power supply apparatus for welder

Welding conditions are set for a power supply apparatus for use with a welding machine, using a control panel unit (). A memory () stores therein welding conditions as set through the control unit (), and holds the set welding conditions after turning off of a main power supply switch () of the power supply apparatus. Upon turning on of the main power switch () for starting welding, the welding conditions stored and held in the memory () are read out and set in the power supply apparatus.

One of a plurality of voltages is adapted to be applied to power supply terminals (). A rectifying circuit () rectifies the applied voltage and develops a rectified voltage between the output terminals () thereof. Inverters () are connected into one of a plurality of inverter connections between the rectifier output terminals () in response to one of a plurality of inverter connection indicative signals. The inverter connections are set to correspond to respective ones of the plurality of voltages, so that a predetermined voltage can be applied to each inverter whichever one of the plurality of voltages is applied to the power supply terminals. An inverter connection indicative signal generating circuit () is manually operated to generate a desired one of the inverter connection indicative signals. A thyristor () is disposed between the rectifier output terminals () and the inverters (). When one of the plurality of voltages is applied to the power supply terminals, a voltage detecting circuit () generates an inverter connection indicative signal corresponding to the voltage applied to the power supply terminals. A judging unit () determines whether or not the inverter connection indicative signals from the voltage detecting circuit () and the inverter connection indicative signal generating circuit () match. When the two signals match, a thyristor control unit () provides a CLOSE signal to the thyristor (). When the two signals do not match, an alarm circuit () is activated.

An opening is formed in a case. Air is caused to flow through the interior of the case. A panel closes the opening. A printed circuit board is disposed behind the panel within the case. A plurality of components, including a control device which can be operated on the front surface of the panel and a display device providing a display viewable on the front surface of the panel, are mounted on the printed circuit board. The printed circuit board is enclosed in a closed receptacle disposed within the case.

An IGBT () intermittently interrupts a current from a positive terminal (P) of a DC supply () to a workpiece (). An IGBT () intermittently interrupts a current from a negative terminal (N) of the DC supply () to the workpiece (). A control circuit () and a drive signal generating circuit () ON-OFF control the IGBTs (). The control circuit () causes the drive signal generating circuit () to control the IGBTs () in such a manner as to provide a repetition of a cycle consisting of an AC period during which the IGBTs () are alternately rendered conductive, and a DC period following the AC period during which the IGBT () is rendered continuously conductive. Further, the control circuit () and the drive signal generating circuit () simultaneously render the IGBT () and the IGBT () nonconductive and conductive, respectively, at least once during the DC period, and, thereafter, simultaneously render the IGBT () and the IGBT () conductive and nonconductive, respectively.

Welding method and welding power supply apparatus

A power supply apparatus has a case ( ) with a control panel ( ) mounted thereon. Plural controllers are disposed on the panel ( ). A cover ( ) is mounted to cover and uncover the panel ( ). One ( ) of the controllers is so disposed as to be externally operable.

A power supply apparatus for a welder includes a rectifier ( ) and a smoothing reactor ( ) which operate together to convert a commercial AC supply voltage to a DC voltage. The DC voltage is converted to a high-frequency voltage by an inverter ( ), which, in turn, is voltage-transformed by a voltage-transformer ( ). The voltage-transformed, high-frequency voltage is converted to a DC voltage by a rectifying diode ( ) and a smoothing reactor ( ), and the resulting DC voltage is applied to a workpiece ( ) and a torch ( ). A current detector ( ) develops a load current representative signal, and a control circuit ( ) so controls a drive circuit ( ) which drives the inverter ( ) that the load current representative signal becomes equal to a reference current signal provided by a reference source ( ). When a small load current is used, a pulse forming switch ( ) is repetitively turned on and off to produce a pulse current from a pulse current setting source ( ). The pulse current is superposed on a control signal from the control circuit ( ).

To provide a recording-reproducing apparatus capable of controlling recorded addresses in a highly-accurate minimum recording unit by using an existing time code in order for recording a signal. The present invention realizes the compatibility of the apparatus with the existing time code and controls the recorded addresses by slightly changing a linear time code signal and assigning a time code corresponding to the minimum recording unit.

Recording-reproducing apparatus for progress TV system

A video production system, which has realized an effective utilization of many existing broadcasting equipments (a time-code generator, an editing controller, etc.) that require a framing with a frequency of 30 Hz and also equipments that function according to a standard of the present time-code defined by a unit of 30 Hz, for a progressive scanning TV format which does not accept a framing by frequency of 30 Hz. An interlaced scanning TV synchronizing signal, which is synchronized of field with a progressive scanning TV signal, is coupled with various kinds of broadcasting equipments (VTRs and , a time-code generator and an editing controller ) from a progressive scanning TV synchronizing signal source . In this way, an entire video production system of the progressive scanning TV format is synchronized with the interlaced scanning TV synchronizing signal, and is capable of being synchronized with 30 Hz. Furthermore, by supplying the interlaced scanning TV synchronizing signal to the entire system, the video production system of the progressive scanning TV format is able to use equipments (an editing controller, a time-code signal generator, etc.) of the conventional interlaced scanning TV format.

Video production system of progress television mode and recording and reproducing device therefor

An input-side rectifier rectifies a commercial AC voltage from a commercial AC power supply connected to an input terminal and develops a rectified voltage between two output terminals. The rectified voltage is smoothed by a pair of capacitors. A switching arrangement connects the capacitors selectively in series and in parallel between the two output terminals. An inverter is associated with each of the capacitors. A high-frequency voltage from each of the inverters is voltage-transformed by a transformer. The high-frequency voltage from the transformer is converted into a DC voltage by a high-frequency-to DC converter for application to a load. When an AC voltage in a lower voltage group is applied to the input terminal, a switching control unit causes the switching arrangement to connect the capacitors in parallel, and when an AC voltage in a higher voltage group is applied to the input terminal, the switching arrangement is caused to connect the capacitors in series. The inverters include IGBTs having a withstanding voltage of about 800 V.

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Osaka, Japan

Takeshi Morimoto