| 摘要 |
PURPOSE:To prevent damage of electrode due to electric discharge dispersion at the time of abnormality and to increase machining speed due to increase in electric discharge frequency at the time of normality by controlling height of pulse voltage applied based on discriminating output of an interpole condition discriminating means. CONSTITUTION:When electric discharging starting voltage is reduced by a control means 30, spark is hard to occur and discharge concentration in an identical interpole clearance can be prevented to prevent damage of an electrode, and when electric discharge concentration is not generated, applied voltage in the interpole clearance is reduced and discharge in the interpole clearance is easily made to increase machining speed. That is, a reverse turn amplifier 100 is a circuit for turning analog voltage Vo according to an output of a counter 25 reversely and applying it to a base of a PNP transistor 102, and interpole voltage Vg applied becomes -R1/R2-VB, and when R1 is made 30kOMEGA and R2 is made 1komega, Vg is changed from 0 to 300V by the change of VB from 0 to 10V, then abnormal spark concentration occurs and when content of the counter 25 is increase, the output of the amplifier 100 is decreased, and voltage Vg is reduced and concentration can be eliminated. |
