APPARATUS FOR THERMOCHEMICAL TREATMENT OF METAL ARTICLES UNDER ELECTRIC GLOW DISCHARGE CONDITIONS

摘要

A circuit arrangement for controlling the power supply to a discharge chamber (9) comprises a power transformer (1) connectable to a power supply (2), two sequentially connected rectifying means (4 and 6) connected across the chamber (9) a short-circuiting element (7) connected across one rectifying means (6) and control means (14). When the voltage across the chamber (9) surpasses a particular threshold voltage element (7) conducts. Control means (14, 15) switches off one rectifying means (6) when it senses this conduction. A second transformer (11) and a condenser (12) are connected across the chamber (9) and a thyristor 13 controlled by control means (14, 15) short circuits part of the second transformer (11) when an arc discharge in the chamber (9) occurs. The time necessary for cleaning work pieces is decreased, the power supplied differs little from the nominal power and the electric strength of the working chamber (9) is restored quickly. The productivity of the chamber (9) is increased. IMAGE