Abstract: A consumable electrode type arc welding apparatus in which arcing can be positively started under a variety of welding conditions. A start current detector selects a predetermined limited start current according to the welding conditions. A start current period setting unit sets a start current period, also in accordance with the welding conditions. A start current control circuit supplies the predetermined limited start current to the workpiece and the wire electrode for the predetermined period of time at the start of arcing.

Abstract: A short circuiting arc welding machine increases an arc current density by adding a pulsed current having upper and lower limits to a current flowing when an arc is produced, thereby increasing the depth of bead penetration into a workpiece, removing welding defects, and speeding up the welding operation. The welding machine is capable of alternately changing the direction of flow of a welding current at desired periods to produce arcs in straight, reverse and mixed polarities for achieving intermediate characteristics of arcs of straight and reverse polarities, with a resultant ability to adjust in a wide range a wire melting rate and the amount of heat applied to the workpiece.

Abstract: An arc welding robot control system includes a control console where a plurality of points on a workpiece taught by a teaching box and a welding voltage, a welding current and a welding speed set by a key board to be specified to each of the taught points are stored in a central control unit and displayed on a cathode ray tube, and a welding electric source for selectively delivering two sets of a welding voltage and a welding current which are specified for a pulsed and a short arc welding process respectively. With the pulsed arc welding process displayed, a set of normally open contacts disposed within the central control unit is closed to cause an electromagnetic contactor disposed within the welding source to operate the source with the that process. Otherwise the contact set is maintained open to operate the source with the short arc welding process.

Abstract: A short circuit transfer arc welding machine including a wire electrode which is fed towards a base metal, a DC source for applying a voltage across the base metal and the wire electrode, a switching element for interrupting the voltage, a voltage detector for detecting a voltage developed across the base metal and the wire electrode, a first comparator for determining when a detection voltage outputted by the voltage detector reaches a voltage value corresponding to the short circuiting of the base metal and wire electrode, a second comparator for determining when the detection voltage of said voltage detector reaches an arc discharge voltage, and a switching element control circuit for closing the switching element in response to a signal from the first comparator and for opening the switching element in response to a signal from the second comparator.

Abstract: A DC welding device is provided with an adder which sums the signals from a base current setting circuit and a shorting current setting circuit and applies the same to a welding current control unit. When a short circuit occurs, the shorting current circuit outputs a gradually increasing signal until the short is removed, whereupon a gradually decreasing signal, which reaches zero after a predetermined time, is output.

Abstract: A power source includes first and second control circuit for controlling the current provided during short-circuit and arc intervals, respectively. A transistor in series with the power supply is controlled in response to either of the control circuits.

Abstract: A welding apparatus is made capable of avoiding the occurrence of welding wire spattering following a short circuit, for example, by providing an arithmetic circuit having a plurality of selectively operated delay elements which smooth the response to a rapid change in welding conditions.

Abstract: A DC arc welding apparatus compares the output voltage with an adjustable, preset voltage, and the amplified and integrated difference signal is supplied to a current control circuit together with a current feedback signal. The resulting apparatus operates in a constant voltage mode, thus rendering it applicable to consumable electrode welding. A constant current mode may also be realized, as an alterantive, by bypassing the comparator and feeding the preset voltage directly to the current control circuit.