| 摘要 |
PROBLEM TO BE SOLVED: To realize an alternating current arc welding machine having extremely high safety by shielding the output of the main circuit for welding until a welding rod and a welding subject are contacted at the count of a prescribed times. SOLUTION: The machine has a decision part 6 for the contact number of times, and a switch 7 inserted in the pass of a drive signal line for the contact point which is output from an apparatus 2 for preventing electric shock to an electromagnetic switch 3. The welding rod for connecting to the output terminal 4 is contacted to the welding subject for connecting to the output 5, the determination part 6 detects the lowering impedance between the outputs 4 and 5 and counts the contact times, and the drive signal is output only when the contact times are achieved to the prescribed several times in the prescribed hours. The switch 7 is closed by the drive signal, the drive signal of the contact point is input to the electromagnetic switch 3 from the apparatus 2 for prevention of electric shock, and the contact point is closed for supplying the welding output to the output terminals 4 and 5. The welding output is shielded until the welding rod and the welding subject are contacted at the count of a prescribed several times in high safety. COPYRIGHT: (C)2003,JPO
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