POWER SUPPLY FOR ELECTRIC DISCHARGE MACHINES

摘要

A power supply for electric discharge machines, wherein switching elements (T2, T3) are turned on in a dischargeable state and a machining current is fed between a work (W) and machining electrode (P) from a low voltage sub-DC power supply (2). When a switching element (T1) is turned on subsequently for a preset time, a high voltage is applied from a main DC power supply (1) and a machining current (J0) rises abruptly. When the switching element (T1) is turned off, the machining current (J0) reaches a peak level which is sustained by a current form the sub-DC power supply (2). When the switching elements (T2, T3) are turned off, a current generated by induction energy is returned through diodes (D1, D2) to the main DC power supply (1) and the machining current drops abruptly.