| 摘要 |
PURPOSE:To prevent accidental short-circuiting between flexible cables and to prevent electric shocks by providing an insulating transformer for step-down between a power source and a gun and grounding one point of the secondary side circuit of the transformer through impedance of low value. CONSTITUTION:The insulating transformer 4 for step-down is installed between the welding power source 10 of rated voltage 200 or 400V having an electronic switch 7 that controls welding current and the gun 1 having a built-in transformer fixed at the tip of the movable arm of a robot 2 to lower applied voltage between cable conductors of flexible cables 3. One point of the flexible cable is connected to ground 6 between the secondary coil side of the insulating transformer 4 and the primary coil side of the gun 1 through impedance 5 of low value, for instance, a resistor of about 100 ohm. By this way, prevention of occurrence of accidental short-circuiting between cables, and restriction of current at the time of short-circuiting become possible. Further, protection from electric shocks to the flexible cable is made possible. |
