POWER SUPPLY FOR ELECTRIC DISCHARGE MACHINES

摘要

When a state for electric discharge is established, switching elements T2 and T3 are turned on so that a machining current J0 from a low-voltage auxiliary DC power source (2) flows between a workpiece (W) and a machining electrode (P). Thereupon, an electric discharge machining current J0 sharply rises as a high voltage is applied from a main DC power source (1). When the switching element T1 is turned off, the electric discharge machining current (J0) reaches its peak value, which is maintained by the current from the auxiliary DC power source (2). When the switching elements T2 and T3 are turned off, a current produced by induced energy is fed back to the main DC power source (1) through diodes D1 and D2, whereupon the machining current sharply falls. <IMAGE>