| 摘要 |
<p>Disclosed is a method for generating a periodically variable welding current (Ip) having high power density and any waveform for a monophase AC or DC operated clocked resistance multispot welding machine. According to said method, the welding current is generated from a three-phase mains voltage source (L1, L2, L3) by means of a controllable, pulse width-modulated current inverter circuit (8), said welding current being predominantly drawn from a rechargeable energy store (7) that is disposed between the mains voltage source and the consumer (1) while only a small portion thereof is drawn from the mains voltage source. The energy store (7) is recharged to a selectable maximum voltage value (Uz) from the mains voltage source by means of a constant mains current (In) during welding breaks, said maximum voltage value (Uz) being greater than the maximum value of the mains voltage (Un). The mains current is adjusted so as to maintain a constant value also during welding, regardless of the quantity and course of the welding current, said mains current obtaining a sinusoidal waveform and being in phase with the mains voltage. The welding current is adjusted to a preselected value by means of a current-regulating device (11) for the current inverter circuit.</p> |
