Sansha Electric Manufacturing Company, Limited

Sansha Manufacturing Co., Ltd.

Tetsuro Ikeda

Hideo Ishii

Kenzo Danjo

Haruo Moriguchi

Takeshi Morimoto

Masayuki Ono

Masao Katooka

Toshikazu Fujiyoshi

Atsushi Kinoshita

Yuji Ikejiri

Toru Arai

Kenji Morimoto

Kunio Shikata

Masahiro Ohashi

Takayuki Nishisako

Kunio Karino

Takeshi Omura

Hiroki Morimoto

Hideo Isii

Kenzo Danjou

Takamitsu Imahori

Fumi Noda

Goro Nakano

An arc welding apparatus includes a main power supply circuit for outputting an arc current, a control circuit for controlling the main power supply circuit, and a high-frequency voltage generating circuit for generating a high-frequency voltage. When an operation switch is turned on for a first time since the apparatus is powered on, the control circuit activates the main power supply circuit to output a high voltage, and the high-frequency voltage generating circuit to generate a high-frequency voltage. With the high voltage superimposed on the high-frequency voltage, the control circuit passes a welding arc current through a torch and a base material. The switch is then turned off, and the control circuit passes a pilot arc current through the torch and the base material. The switch is turned on again, and the control circuit activates the main power supply circuit to output a high voltage, thereby allowing smooth arc transition.

Arc welding apparatus and method

A plasma arc power supply with a simple structure and its control method enable shifting from a pilot arc to a main arc. A plasma arc power supply used in a plasma arc apparatus that processes a workpiece by forming a pilot arc between a main electrode and a nozzle electrode and subsequently forming a main arc between the main electrode and the workpiece includes N direct current power supply units (N&#x2267;2) having negative terminals connected to the main electrode and positive terminals to the workpiece, and a switch between the fourth power supply unit and the workpiece. The fourth power supply unit is connected to cause the nozzle electrode to have an opposite polarity to the main electrode. When the switch is open, the fourth power supply unit supplies a small current between the main electrode and the nozzle electrode while forming a pilot arc between them.

Plasma arc power supply and control method therefor

Lighting of a discharge lamp is controlled in a manner to reduce deterioration of the discharge lamp subjected to high temperature and extend the lifetime of the discharge lamp. A method for controlling lighting of the discharge lamp includes a first constant current control process (period T, which corresponds to steps Sand S) in which constant current control is executed by supplying a first current to the discharge lamp, a second constant current control process (period T, which corresponds to steps Sand S) in which constant current control is executed by supplying a second current greater than the first current to the discharge lamp after the first constant current control process, and a constant power control process (period T) in which constant power control is executed after the second constant current control process.

Discharge lamp lighting control method, computer program, discharge lamp lighting control apparatus, and power supply circuit

A rectifying circuit () converts inputted AC power to DC power. An inverter circuit () converts the DC power to high-frequency power in accordance with a switching control signal applied thereto from a control circuit (). A voltage transformer () voltage-transforms the voltage of the high-frequency power. An output-side rectifying circuit () rectifies the voltage-transformed power. An output detecting circuit () detects the magnitude of the voltage of the rectified power, and a signal representative of the detected voltage is applied to the control circuit (). The control circuit () generates such a switching control signal as to make the rectified power have a predetermined value. The value of the voltage from the rectifying circuit () is detected by an input detecting circuit (), and a signal representative of the detected voltage is applied to the control circuit (). The control circuit () controls the operation of the inverter circuit () in accordance with the detected voltage representative signal from the input detecting circuit () and the saturation magnetic characteristic of the voltage-transformer ().

Power supply apparatus

Energy loss due to driving a plurality of power supply units simultaneously in a low-current region is prevented, and a more stable load current is obtained. The generation of a load current in a small-current region from a pilot arc current is handled solely by the power supply unit U, the remaining (N&#x2212;1) power supply units Uthrough Uare driven when the small-current region is exceeded, and a current that is the composite of all the currents is fed to the load, whereby a stable plasma arc power supply is obtained in which power consumption in the low-current region is reduced.

Plasma arc power supply and control method for same

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

A power supply apparatus for use with arc-utilizing apparatuses includes a plurality of power supply blocks of the same capacity. Each power supply block includes an input-side rectifying circuit, an inverter, a transformer, and an output-side rectifying circuit. The inverter is controlled by a control circuit in such a manner that high-frequency current flowing the inverter or current flowing through the output-side rectifying circuit can correspond to a reference signal provided by a reference signal generator. The outputs of the output-side rectifying circuits of the power supply blocks are connected in parallel with each other. The values of the reference signals generated by the reference signal generators are made always equal by the action of equipotential lines.

Power supply apparatus for arc-utilizing apparatuses

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 input rectifier of a power supply apparatus rectifies a selected one of two, higher and lower AC voltages applied to it. First and second inverters are connected in the output of the input rectifier. A high-frequency transformer is connected to the output of each of the first and second inverters. An output rectifier is connected to the output of each of the high-frequency transformers. When the higher one of the two AC input voltages is applied to the input rectifier, a switching circuit connects the first and second inverters in series between output terminals of the input rectifier. When the lower AC voltage is applied to the input rectifier, the switching circuit connects the first and second inverters in parallel between the output terminals of the input rectifier. When the first and second inverters are connected in series between the output terminals of the input rectifier, a voltage balancing control unit operates to suppress imbalance between input voltages to the first and second inverters.

Power supply apparatus for arc-utilizing apparatus

Metallic coils sheets ( ) are planar and include center windows ( ). Slits ( ) extend outward through the respective sheets from the windows. Connection terminals ( ) are provided on the sheets at locations facing across the respective slits. The metallic coil sheets are stacked, and adjacent ones of the stacked metallic coil sheets are electrically connected by means of the connection terminals. A core ( ) is disposed in the windows of the stacked metallic coil sheets. The metallic coil sheets are individually covered with an insulating coating.

Coil

A high-frequency large current handling transformer includes a stack of plural metal planar coil members with a window formed in a center portion of each of the planar coil member. A slit extends outward from the window in each planar coil member. First and second terminals are provided for each planar coil member at locations on opposite sides of the slit. An insulating sheet having a window formed in its center portion is disposed between adjacent ones of the planar coil members. Some of the planar coil members are connected in series to provide a higher-voltage side coil, and the remaining planar coil members are connected in parallel to provide a lower-voltage side coil. An 8-shaped high-frequency core is operatively combined with the coils.

High-frequency large current handling transformer

A DC power supply apparatus has two power supply input terminals between which one of 100 V level, 200 V level and 400 V level AC power supply voltages or a 575 V AC power supply voltage is applied. A rectifying unit is connected between the two power supply input terminals, and a voltage-lowering converter is connected to the rectifying unit. A thyristor is connected between the input and output of the voltage-lowering converter. A series combination of two capacitors is connected between two output terminals of the voltage-lowering converter. A switch circuit is connected between the junction of the two capacitors and one input terminal of the rectifying unit. An inverter converts a DC voltage appearing across the series combination of the capacitors into a high-frequency voltage, which, in turn, is voltage transformed by a transformer. The voltage-transformed high-frequency voltage is converted into a DC voltage in a high-frequency-to-DC converter for application to a load. When a 100 V level voltage is applied between the power supply input terminals, the thyristor is turned on, the voltage-lowering converter is turned off and the switch circuit is turned on. When one of the 200 V level voltages is connected, the thyristor is turned on, the voltage-lowering converter is turned off, and the switch circuit is turned off. When one of the 400 V level voltages or the 575 V voltage is applied between the power supply input terminals, the thyristor is turned off, the voltage-lowering converter is turned on, and the switch circuit is turned off.

DC power supply apparatus for arc-utilizing apparatuses

One of commercial AC voltages is coupled to power supply terminals from one of commercial AC power supplies. The AC power supplies belong to either a first group providing higher voltages or a second group providing lower voltages. A rectifier rectifies the AC voltage applied to the power supply terminals, and a rectified voltage is developed between two rectifier output terminals. A switching unit operates to connect voltage-boosting converters selectively in series and in parallel between the rectifier output terminals. Inverters are connected in the output sides of and in association with the respective voltage-boosting converters for converting DC voltages from the associated voltage-boosting converters to high-frequency voltages. The high-frequency voltages are voltage-transformed by associated voltage-transformers, and the voltage-transformed high-frequency voltages are converted into a DC voltage by a rectifier circuit and a reactor. The DC voltage is developed between output terminals of the apparatus. A switching control unit controls the switching unit so as to connect the voltage-boosting converters in series between the rectifier output terminals when a commercial AC power supply of the first group is connected to the power supply terminals, while connecting the voltage-boosting converters in parallel between the rectifier output terminals when a commercial AC power supply of the second group is connected to the power supply terminals.

A DC voltage from a DC supply is applied to inverters of two power supply units connected in parallel with each other. The inverters convert the received DC voltages into high-frequency voltages, which are, in turn, voltage-transformed in transformers. The outputs of the transformers are rectified in two rectifiers, respectively, and smoothed in two reactors. The smoothed voltages are supplied between output terminals. The reactors are formed on a single core, being loosely coupled with each other.

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Osaka, Japan

Tetsuro Ikeda