摘要 |
<p>In accordance with the method, the arc supplying current is modulated if necessary for generating an acoustical signal. The acoustical signal generated by the arc is detected and its amplitude which, in practice, is a direct function of the actual length of the arc, is compared to a reference amplitude corresponding to the desired length of the electrical arc, in order to determine the algebraic value of their difference. This algebraic value is used for monitoring at least one element of the machine between which the arc forms, and moving this element proportionally to the so-determined algebraic value in order to increase or reduce the actual length of the arc and to bring this length back to the desired length.</p> |