PURPOSE: To prevent are break surely and perform stable arc welding, by providing a circuit that detects a background current and when the value shifts from a specified value, and maintaining the specified value by bringing a switching element into conduction.
CONSTITUTION: A background current is detected by a shunt 12 for current detection and the signal is amplified by an amplifier 13. A comparator 14 compares the compared voltage Va and current signal I, and when the current signal is below Va, generates H signal. An oscillator 15 outputs waveform (C). An AND gate 16 executes AND to (B), (C) and outputs (D). An OR gate 17 utilizes a pulse driving signal outputted from a pulse generating circuit 10 and a signal from the AND gate 16, and generates a transistor driving signal of (E). Thus, while the background current is maintained below the specified value, a transistor 6 is conducted and stiffness of the arc is increased, and operated to maintain stable arc.
NISHIDA YORIAKI
KAWAI NAOKI
| JPS5719166A | 1982-02-01 | |||
| JPS5719163A | 1982-02-01 | |||
| JPS5744474A | 1982-03-12 |