| 摘要 |
<p>The appts. includes a controlled frequency converter with a hald period shorter than the average duration of the contact current and voltages caused by short circuits due to molten drops of welding material. The converter is connected via a transformer and rectifier to the electrodes; and a controller adjusts the converter so the welding current is constant despite the changes in load. The pref. controller continuously monitors arc current (A) and voltage (V), and includes a circuit measuring the voltage (P1) proportional to A x V. P1 is compared with a reference voltage (P2) representing the desired welding current, and the converter is adjusted to bring the difference P2-P1 to zero. The working frequency of the converter is pref. held constant; and capacitors and logic elements are included. Arc welding is simplified so that even semi-skilled workers can make good welds.</p> |
