Abstract: In an arc start ancillary apparatus, which is connected in parallel to a welding power source for supplying electric power necessary for arc discharge between an electrode and a base metal, for supplying a pulsed electric current in transferring from spark discharge to arc discharge, an object of the present invention is to solve a problem in that arc is not started, and to keep the effective value of current low. A capacitor with a relatively high capacitance is connected to secure a current for transferring from spark discharge to arc discharge, and a D.C. high voltage of a high voltage generator is applied according to a pulse in a period to which the period of pulse signals of a fixed period type high voltage controller is set so that the effective value of the current between an electrode and a base metal is kept low.

Abstract: A consumable electrode type pulsed arc welder and a controlling method for the same, wherein at least one of a welding current and a welding voltage is output to a wire in accordance with a duty time of a pulse waveform group comprising a first pulse period to form a droplet having a predetermined amount at an end of the wire, a base period to shorten an arc length between the droplet and a base metal, and a second pulse period to detach the droplet.

Abstract: A welding power control apparatus that removes the effects of shorting and noise to accurately detect droplet separation, thereby reducing spatter during droplet separation and when shorting occurs, and stabilizing welding results is achieved. Welding conditions such as welding voltage, welding current, shorting, and droplet separation are detected. Based on thus detected welding conditions, a pulse wave configuration unit generates a steady-state pulse wave and a compensation pulse wave. The steady-state pulse wave is defined by a pulse height for a pulse period and a base height lower than the first pulse height for a base period. The compensation pulse wave defined by a compensation pulse height lower than the pulse height for a compensation period followed by the pulse wave based on said detected welding conditions.

Abstract: In a consumable electrode type pulsed arc welder using a CO.sub.2 shielding gas a voltage detected by a detector (13) is given to a comparator (14) to which a reference voltage of a voltage setting circuit (15) is also inputted. When the detected voltage exceeds the reference voltage, a droplet detachment detection signal is issued. Then, an output adjusting circuit (16) lowers the welder output to a level I.sub.r lower than the ordinary current I.sub.p.

Abstract: A welding voltage output from a power source of a resistance welder is derived on the basis of a welding current and an interelectrode voltage, and diameter of a nugget which is formed in a sheetlike work to be welded is estimated on the basis of the welding current, the welding voltage, data of material constant and a thickness of the sheetlike work, subsequently, the estimated diameter of nugget is composed with a target diameter of nugget, and thereby quality of the resistance welding is determined.