Abstract: A gas shielded arc welding torch is described which uses a consumable electrode wire. A cylindrical support member carries a guide tube for guiding the electrode wire through the torch. An electrical contact member is pivotably mounted at the end of the torch and includes a bore through which the wire passes. A spring biases the contact member into constant engagement with the electrode wire. A gas nozzle is mounted on the cylindrical support member and is movable with the contact member to provide a uniform, constant-dimensioned shielding gas passage around the contact member regardless of the movement thereof.

Abstract: A photovoltaic device comprising at least one crystalline and one amorphous semiconductor region with different photosensitivity is provided to absorb light in a wide range of wavelength, and serves, for example, as a solar battery or a color sensor. Amorphous or microcrystalline semiconductor regions comprising those devices can be deposited easily and in a continuous manufacturing process by the use of a low temperature process, and this allows manufacture of a photovoltaic device at low cost.

Abstract: An improved welding torch which includes a contact member constituted by a power feeding member having a through-opening for passing a consumable electrode wire and a support member for supporting the power feeding member, an electrode wire guide member covered, at least at its forward end portion, by the contact member, with at least the forward end portion of the guide member and the contact member being arranged to be movable with respect to each other in direction intersecting generally at right angles with an axis of the electrode wire, and a pressure member for relatively urging the contact member and the guide member for holding the electrode wire.

Abstract: A pulse arc welding device includes a power source which produces a background current and pulse current imposed on it. A voltage drop across the arc is measured and when such a voltage drop deviates from a predetermined level, either one of background current, frequency of the pulse current and pulse duration of the pulse current is controlled to maintain the voltage drop across the arc constant.

Abstract: An a.c. arc welder includes a reactor between a source of a.c. power and a welding load for accumulating energy during the increase of voltage from the source. A bypass circuit is further provided in parallel to the reactor and the welding load for dissipating the accumulated energy as a welding current through the load.

Abstract: A method and apparatus for controlling the welding current in shortcircuit transfer arc welding including a method and control apparatus for maintaining the effective value of the welding current during arcing period at a predetermined value. Maintenance of the effective value of welding current during arcing period is necessary to keep the size of a fusion zone and the depth of penetration constant throughout welding operation.

Abstract: The present disclosure relates to an automatic arc welder for welding two metal plates together along a line of joint formed between the two metal plates. The welder has a welding unit including a welding torch mounted on a carrier member for performing the welding as the carrier member travels along the line of joint. Since the welding unit is rotatably supported on a frame member, while the frame member is pivotally mounted, through a suitable bracket, on the carrier member, the positioning of the welding torch can be varied with respect to different types of weldings.

Abstract: An AC arc welder which comprises means for detecting the welding current, a comparison circuit for generating logical output signals by comparing the output voltage or output current of the welding current detecting means with the reference voltage or reference current from a reference voltage generating means, digital means for generating logical output signals by performing adding operation or subtracting operation in response to the logical output signal, current supplying means for supplying the output current whose common ratio becoming the geometrical series of approximately m(m = 1, 2, 3 . . . ), and switching means for on and off- controlling the output of the current supplying means in response to the logical output signals of the digital means, thus forming a current feedback loop, whereby the output current from the current supplying means can be changed minutely, thus ensuring stabilized control characteristics.