Abstract: A fan control unit includes: an internal fan that is provided inside a casing, in which an inverter containing a switching element is disposed, and generates an air current for air-cooling inside the casing; a heat sink which is exposed inside a duct provided on the casing and to which the switching element is attached, the duct being provided with an air-intake port and an air-exhaust port; an air-intake fan disposed at the air-intake port of the duct; an air-exhaust fan disposed at the air-exhaust port of the duct; and a control section performing a control such that the air-exhaust fan is turned on earlier than the air-intake fan and the internal fan as output power increases, and that the internal fan and the air-intake fan are turned off earlier than the air-exhaust fan as output power decreases from a state in which all the fans are kept turned on.

Abstract: A welding machine power supply apparatus outputs welding current in accordance with welding conditions set through operation of a display and setting unit (20). 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 (16). 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 (70), a rotary encoder (64) and a set button (72) are operated to cause a control unit (14) to read out the welding conditions stored in the memory (16) which were effective when the welding operation was ended, and to set the read-out welding conditions in the welding machine power supply apparatus.

Abstract: A DC-DC converter includes a regeneration snubber circuit. The snubber circuit is connected in parallel with the secondary diode circuit and includes a series circuit of a discharge blocking diode, a snubber capacitor, and a switching element for regeneration connected in parallel with the discharge blocking diode. The DC-DC converter further includes a control unit which turns the switching element for regeneration on a predetermined time period after the timing of turning the primary side switching element off. The predetermined time period is set to approximately the time period during which the charge, accumulated in the snubber capacitor due to reverse recovery time when one of the secondary diodes has been turned off, discharges.

Abstract: A utility interconnection inverter device (7) includes an inverter circuit (21) that converts DC power generated by a solar panel (3) to AC power by switching a plurality of switching elements, and a controller (39) that controls the plurality of switching elements. Moreover, fans (43, 45) are provided for cooling the plurality of switching elements. Furthermore, a power supply circuit (a terminal 38, a transformer 40, and a power circuit 41) is provided, and supplies power from a control power supply (10) to the controller (39) and the fans (43, 45).

Abstract: Provided is a PIN diode that can suppress thermal destruction from occurring at the time of a reverse bias exceeding a breakdown voltage by current concentration on a curved part of an anode region. The PIN diode is configured to have: a semiconductor substrate 11 that includes an N+ semiconductor layer 1 and an N? semiconductor layer 2; a cathode electrode 18 that is formed on an outer surface of the N+ semiconductor layer 1; a main anode region 16, a separated anode region 15, and an anode connecting region that are formed by selectively diffusing P-type impurities from an outer surface of the N? semiconductor layer 2; and an anode electrode 17 that is formed on the main anode region 16.

Abstract: 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.

Abstract: A PIN diode having improved avalanche resistance is provided. The PIN diode includes: a semiconductor substrate 11 that includes an N+ semiconductor layer 1, and an N? semiconductor layer 2; a P-type anode region 15 that is formed by selective impurity diffusion into an outer surface of the N? semiconductor layer 2; and an anode electrode 17 that is conducted to the anode region 15 through a contact region 17c in the anode region 15. The anode region 15 has a substantially rectangular outer edge of which four sides are adapted to be linear parts B2 and four vertices are adapted to be curved parts B1, and outside the contact region 17c, N-type non-diffusion corner regions 16 that extend along the curved parts B1 are respectively formed.

Abstract: This inverter circuit includes first and second switching elements and an output transformer which is provided with a first primary winding connected in series between said first and second switching elements, and also with a secondary winding for obtaining an output voltage. The inverter circuit is further provided with a first voltage supply, a second voltage supply, and a control unit. The first voltage supply applies voltage to said first switching element via said first primary winding. And the second voltage supply applies voltage to said second switching element via said second primary winding. The control unit turns said first switching element and said second switching element alternatingly ON and OFF. This inverter circuit also includes first and second regeneration snubber circuits for regenerating the charge charged into snubber capacitors.

Abstract: This DC-DC converter circuit includes: first and second switching elements (S1, S2); an output transformer (T) that includes a first primary winding (P1) connected in series between the positive electrode sides of the first and second switching elements (S1, S2), a second primary winding (P2) connected in series between their negative electrode sides, a secondary winding (S) for obtaining an output voltage, and tertiary windings (n3, n4); a first voltage source (C1), connected between a first connection point at which the first primary winding (P1) is connected to the second switching element (S2) and the first switching element (S1), that applies a voltage to the first switching element via the first primary winding; a second voltage source (C2) connected to locations symmetric with those of the first voltage source (C1); and a control unit (CT) that turns the first and second switching elements (S1, S2) alternatingly ON and OFF, and first and second regeneration snubber circuits (SN1, SN2) for regenerating

Abstract: Provided is a PIN diode that can suppress thermal destruction from occurring at the time of a reverse bias exceeding a breakdown voltage by current concentration on a curved part of an anode region. The PIN diode is configured to have: a semiconductor substrate 11 that includes an N+ semiconductor layer 1 and an N? semiconductor layer 2; a cathode electrode 18 that is formed on an outer surface of the N+ semiconductor layer 1; a main anode region 16, a separated anode region 15, and an anode connecting region that are formed by selectively diffusing P-type impurities from an outer surface of the N? semiconductor layer 2; and an anode electrode 17 that is formed on the main anode region 16.

Abstract: A PIN diode having improved avalanche resistance is provided. The PIN diode includes: a semiconductor substrate 11 that includes an N+ semiconductor layer 1, and an N? semiconductor layer 2; a P-type anode region 15 that is formed by selective impurity diffusion into an outer surface of the N? semiconductor layer 2; and an anode electrode 17 that is conducted to the anode region 15 through a contact region 17c in the anode region 15. The anode region 15 has a substantially rectangular outer edge of which four sides are adapted to be linear parts B2 and four vertices are adapted to be curved parts B1, and outside the contact region 17c, N-type non-diffusion corner regions 16 that extend along the curved parts B1 are respectively formed.

Abstract: A non-consumable electrode type arc welding apparatus includes a torch having an electrode portion and a nozzle, a gas supply that supplies, to the torch, a shielding gas flowing through a gap formed between the electrode portion and the nozzle, a first power source that applies a voltage between the electrode portion and the nozzle to generate a pilot arc, a second power source that applies a voltage between the electrode portion and a work to generate a main arc, and a controller that controls the first power source and the second power source. The electrode portion has an electrode and an electrode holding portion holding a base portion of the electrode, the electrode holding portion has a protrusion protruding toward the nozzle from the side facing the nozzle, and the protrusion and the nozzle are caused contact and separate from each other.

Abstract: A power supply unit of an arc discharge device includes a semiconductor module 1 and a radiator fitted onto the semiconductor module 1. The semiconductor module 1 includes a module casing 2 and common units 3a to 3c retained by the module casing 2. Each of the common units 3a to 3c has: a ceramic substrate 50 having a circuit surface disposed with a semiconductor element 54 and a radiation surface on a side opposite to the circuit surface and a package 35 that exposes the radiation surface and seals the circuit surface with heat resistant resin. The radiator is fitted onto the module casing 2 to be thereby brought into abutting contact with all of the radiation surfaces of the common units 3a to 3c.

Abstract: This inverter circuit includes two switching elements which are turned alternately ON and OFF, and a first primary winding connected in series between these switching elements, and also includes an output transformer having a secondary winding for obtaining an output voltage. This inverter circuit also includes a first voltage source and a second voltage source. The first voltage source applies a voltage to the first switching element via the first primary winding. And the second voltage source applies a voltage to the second switching element via the second primary winding. This inverter circuit also includes a regeneration snubber circuit for regenerating charge accumulated in a snubber capacitor. The regeneration snubber circuit includes a regeneration circuit including a voltage boost section which converts the primary side voltage of the output transformer to a predetermined voltage, which it outputs.

Abstract: This inverter circuit includes first and second switching elements and an output transformer which has a first primary winding connected in series between the first switching element and the second switching element and a second primary winding for obtaining an output voltage. The inverter circuit also includes a first voltage source, a second voltage source, and a control unit. The first voltage source is connected between a first connection point at which the first primary winding is connected to the second switching element, and the first switching element, and applies a voltage to the first switching element via the first primary winding. And the second voltage source is connected between a second connection point at which the first primary winding is connected to the first switching element, and the second switching element, and applies a voltage to the second switching element via the first primary winding.

Abstract: This current balanced push-pull type inverter circuit includes first and second switching elements, and an output transformer which includes a first primary winding and a second primary winding connected in series between said first and second switching elements, and also includes a secondary winding for obtaining an output voltage. This inverter circuit also includes a first voltage supply capacitor, a second voltage supply capacitor, and a control unit. A first snubber circuit, in which a first free wheel diode and first and second snubber capacitors are connected in series, is connected in inverse parallel to the first switching element. A first discharge resistor is connected between the first snubber capacitor and a first power supply capacitor, and a second discharge resistor is connected between the second snubber capacitor and a third power supply capacitor. And a second snubber circuit and discharge resistors are connected to the second switching element as well, in a similar manner.

Abstract: This power supply device includes a series circuit of a first switching element and a second switching element connected in parallel with a DC power supply unit, and a smoothing filter circuit which includes a series circuit of an inductor and a smoothing capacitor connected in parallel with the second switching element. The power supply device also includes a control unit and a drive circuit for generating first and second PWM pulses by respectively driving the first and second switching elements ON and OFF, and for creating a dead time between those switching pulse signals. And this control unit changes the frequency of the switching pulse signal according to the pulse width of either the first PWM pulses or the second PWM pulses.

Abstract: This converter for electrical power recovery (1) for supplying power to a load (6) includes an in-house power generation device (5) for supplying power in cooperation with input terminal power at a power input terminal (2). Moreover, it includes a thermal storage unit (12) which, when surplus power is generated in a state in which a target value for input terminal power is set to zero, thermally stores this power. Furthermore, a control unit (9) is included which, when surplus power is generated, decides whether or not breakage of a wire of a CT (7) has occurred by raising the target value for the input terminal power from zero to a predetermined value, and by deciding whether or not the power input terminal current is somewhat elevated from zero.

Abstract: To suppress warpage of a ceramic substrate, and to prevent a reduction in radiation efficiency. A power semiconductor module includes a module casing fitted with a radiator, and a common unit retained by the module casing. The common unit has: a ceramic substrate having a circuit surface disposed with a semiconductor element, and a radiation surface brought into abutting contact with the radiator; and a package formed by exposing the radiation surface and sealing the circuit surface with heat resistant resin. The circuit surface and the radiation surface are respectively formed of metal layers 51 formed on the ceramic substrate, and the metal layer 51 forming the radiation surface has: by forming a buffer pattern 512 including a groove part extending along a circumferential part thereof, a radiation pattern 510 formed on an inner side of the buffer pattern 512; and an outer peripheral pattern 511 formed on an outer side of the buffer pattern 512.

Abstract: 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 T1, which corresponds to steps S3 and S4) in which constant current control is executed by supplying a first current to the discharge lamp, a second constant current control process (period T3, which corresponds to steps S7 and S8) 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 T4) in which constant power control is executed after the second constant current control process.