Abstract: A printed circuit board (120) includes an insulating substrate (120a) on which conductive films (120b) are formed. Semiconductor devices (8) disposed external to the printed circuit board (120) have their leads (24a, 24b, 24c) connected to the conductive films. A flexible portion (30) is formed in the insulating substrate (120a) at a location near the location where the leads (24a, 24b, 24c) are connected to the conductive films (120b).

Abstract: A printed circuit board (120) includes an insulating substrate (120a) on which conductive films (120b) are formed. Semiconductor devices (8) disposed external to the printed circuit board (120) have their leads (24a, 24b, 24c) connected to the conductive films. A flexible portion (30) is formed in the insulating substrate (120a) at a location near the location where the leads (24a, 24b, 24c) are connected to the conductive films (120b).

Abstract: A printed circuit board (120) includes an insulating substrate (120a) on which conductive films (120b) are formed. Semiconductor devices (8) disposed external to the printed circuit board (120) have their leads (24a, 24b, 24c) connected to the conductive films. A flexible portion (30) is formed in the insulating substrate (120a) at a location near the location where the leads (24a, 24b, 24c) are connected to the conductive films (120b).

Abstract: One of a plurality of voltages is adapted to be applied to power supply terminals (2a, 2b, 2c). A rectifying circuit (6) rectifies the applied voltage and develops a rectified voltage between the output terminals (6a, 6b) thereof. Inverters (16a, 16b) are connected into one of a plurality of inverter connections between the rectifier output terminals (6a, 6b) 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 (34) is manually operated to generate a desired one of the inverter connection indicative signals. A thyristor (8) is disposed between the rectifier output terminals (6a, 6b) and the inverters (16a, 16b).

Abstract: A heat-generating component cooling structure includes a hollow heat sink having a portion made of a thermally conductive material. The heat sink has an interior path extending from first to second ends of the heat sink. A fan device is disposed at the first end of the heat sink and is adapted to cause air to flow through the interior path. Fins are disposed in the path in the heat sink. Heat-generating components of an electrical circuit are mounted on an outer surface of the heat sink.

Abstract: An attachment (10) for preventing a cover (4) from falling off from a housing (1) is provided. The cover (4) includes an elastic member (54) on each of the right and lefts ends thereof. The elastic members are made elastically deformable by forming slits (56) in the cover (4). The elastic members (54) each have a protrusion (52). In order to mount the cover (4) to the housing (1), the protrusions (52) are inserted into respective ones of holes (7) formed in the housing (1) by inwardly deforming and, then, restoring the elastic members (54). After mounting the cover (4) to the housing (1), the cover falling-off preventing attachment (10) is attached to the cover (4), with side walls 18 of the attachment (10) positioned to extend into the respective slits (56), whereby the deformation of the elastic members (54) is prevented.

Abstract: 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.

Abstract: One of a plurality of voltages is adapted to be applied to power supply terminals (2a, 2b, 2c). A rectifying circuit (6) rectifies the applied voltage and develops a rectified voltage between the output terminals (6a, 6b) thereof. Inverters (16a, 16b) are connected into one of a plurality of inverter connections between the rectifier output terminals (6a, 6b) 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 (34) is manually operated to generate a desired one of the inverter connection indicative signals. A thyristor (8) is disposed between the rectifier output terminals (6a, 6b) and the inverters (16a, 16b).

Abstract: An attachment (10) for preventing a cover (4) from falling off from a housing (1) is provided. The cover (4) includes an elastic member (54) on each of the right and lefts ends thereof. The elastic members are made elastically deformable by forming slits (56) in the cover (4). The elastic members (54) each have a protrusion (52). In order to mount the cover (4) to the housing (1), the protrusions (52) are inserted into respective ones of holes (7) formed in the housing (1) by inwardly deforming and, then, restoring the elastic members (54). After mounting the cover (4) to the housing (1), the cover falling-off preventing attachment (10) is attached to the cover (4), with side walls 18 of the attachment (10) positioned to extend into the respective slits (56), whereby the deformation of the elastic members (54) is prevented.

Abstract: 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.

Abstract: A printed circuit board (120) includes an insulating substrate (120a) on which conductive films (120b) are formed. Semiconductor devices (8) disposed external to the printed circuit board (120) have their leads (24a, 24b, 24c) connected to the conductive films. A flexible portion (30) is formed in the insulating substrate (120a) at a location near the location where the leads (24a, 24b, 24c) are connected to the conductive films (120b).

Abstract: A heat-generating component cooling structure includes a hollow heat sink having a portion made of a thermally conductive material. The heat sink has an interior path extending from first to second ends of the heat sink. A fan device is disposed at the first end of the heat sink and is adapted to cause air to flow through the interior path. Fins are disposed in the path in the heat sink. Heat-generating components of an electrical circuit are mounted on an outer surface of the heat sink.

Abstract: A power supply apparatus has a case (94) with a control panel (96) mounted thereon. Plural controllers are disposed on the panel (96). A cover (98) is mounted to cover and uncover the panel (96). One (66) of the controllers is so disposed as to be externally operable.

Abstract: A power supply apparatus for a welder includes a rectifier (104) and a smoothing reactor (106) 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 (108), which, in turn, is voltage-transformed by a voltage-transformer (110). The voltage-transformed, high-frequency voltage is converted to a DC voltage by a rectifying diode (112) and a smoothing reactor (114), and the resulting DC voltage is applied to a workpiece (118a) and a torch (118b). A current detector (120) develops a load current representative signal, and a control circuit (122) so controls a drive circuit (126) which drives the inverter (108) that the load current representative signal becomes equal to a reference current signal provided by a reference source (124). When a small load current is used, a pulse forming switch (140) is repetitively turned on and off to produce a pulse current from a pulse current setting source (139).

Abstract: Metallic coils sheets (34, 36, 38) are planar and include center windows (34a, 36a, 38a). Slits (34b, 36b, 38b) extend outward through the respective sheets from the windows. Connection terminals (34c, 34d; 36c, 36d; 38c, 38d) 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 (60, 62) is disposed in the windows of the stacked metallic coil sheets. The metallic coil sheets are individually covered with an insulating coating.

Abstract: A power supply apparatus has chassis (42, 44) mounted on opposing surfaces of a heat sink (40). Printed circuit boards (46, 48) are disposed outward of the chassis (42, 44) and detachably secured to the chassis (42, 44). Semiconductor modules (4, 16a, 16b, 32) are mounted on the respective surfaces of the heat sink (40) facing toward the printed circuit boards (46, 48) and extend through the chassis (42, 44). The semiconductor modules (4, 16a, 16b, 32) are electrically connected to the printed circuit boards (46, 48) to form a power supply circuit.

Abstract: Metallic coils sheets (34, 36, 38) are planar and include center windows (34a, 36a, 38a). Slits (34b, 36b, 38b) extend outward through the respective sheets from the windows. Connection terminals (34c, 34d; 36c, 36d; 38c, 38d) 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 (60, 62) is disposed in the windows of the stacked metallic coil sheets. The metallic coil sheets are individually covered with an insulating coating.

Abstract: A power supply apparatus for a welder includes a rectifier (104) and a smoothing reactor (106) 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 (108), which, in turn, is voltage-transformed by a voltage-transformer (110). The voltage-transformed, high-frequency voltage is converted to a DC voltage by a rectifying diode (112) and a smoothing reactor (114), and the resulting DC voltage is applied to a workpiece (118a) and a torch (118b). A current detector (120) develops a load current representative signal, and a control circuit (122) so controls a drive circuit (126) which drives the inverter (108) that the load current representative signal becomes equal to a reference current signal provided by a reference source (124). When a small load current is used, a pulse forming switch (140) is repetitively turned on and off to produce a pulse current from a pulse current setting source (139).

Abstract: 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.