Power source for plasma arc

Abstract

Abstract PURPOSE:To improve stability of a pilot arc and to reduce size and weight of the titled power source by controlling a pilot arc current having a function to open a pilot arc circuit which is shifted to a main arc current and the main arc current respectively by the constant current. CONSTITUTION:A pilot arc current detector 20 and a low resistance 24 are inserted into the pilot arc circuit and moreover, a detected signal from the detector 20 is compared to a set signal from a pilot arc current setter 21 with a comparison part 22 to control the pilot arc current by the constant current. At this time, both of the comparison parts 17 and 2 are in an operating state till the main arc current is detected by a relay driving circuit 19 and detected values from the detectors 15 and 20 are controlled so as not to exceed either of set values of the setters 16 and 21. The low resistance 24 is selected to a low-resistance value to an extent that it does not receive an electric shock even in case the generating voltage comes into contact with a nozzle 14 even when the maximum current is allowed to flow to the pilot arc circuit and useful for reducing the size and weight of the power source.

Inventors

• 👤 Takayuki Kashima
• 👤 孝之 鹿島
• 👤 Tsuneo Shinada
• 👤 常夫 品田
• 👤 Shozo Sekiuchi
• 👤 関内　正三

Bibliographic Details