Supply for electro-chemical process equipment - uses transformer and rectifier to produce controlled supply to workpiece and electrode

摘要

The workpiece (2) and electrode (3) are coupled to the d.c circuit that is fed by a d.c generating stage (4) coupled to the 50 Hz a.c mains. The d.c supply consists of a transformer with a primary winding (6A) and secondary windings (7,8) each star connected with controlled rectifier stages. The common points of the star windings are coupled over a coil (9) connected to the workpiece. Currents supplied to the primary windings are detected (11-13) and rectified (14) to provide an input to an amplifier (18) over a smoothing stage (16). The amplifier output is proportional to the current supplied to the electrode (10).