Controller for arc welding robot

An arc welding robot control unit for controlling the output of a welding machine and the operation of a robot in an integral manner, comprising:

• a robot control part;
• an inverter circuit for enforcing arc welding;
• a capacitor for driving the inverter circuit stably;
• a main power supply switch for turning on and off a main power supply for supplying power to the inverter circuit;
• a standby charge path for standby charging the capacitor before the main power supply switch turns on the main power supply;
• an opening/closing switch for opening and closing the standby charge path for standby charging the capacitor;
• a manually operated button for turning on and off the main power supply;
• a main power supply control part for controlling the on and off of the main power supply in accordance with an instruction indicating whether there is a demand for welding machine output;
• and
• an emergency stop button for emergency stopping the operation of the robot,
• wherein, when the emergency stop button is depressed to thereby put the robot into emergency stop the opening/closing switch and the main power supply switch are also substantially simultaneously opened to cut off the power supply path to the inverter circuit.