Safety circuit for teaching operation of robot

A robot comprising:

• a robot body capable of being taught procedure of a task;
• a teaching portion including a deadman switch for operation by an operator to make indication by its opened/closed state as to whether or not said procedure is being taught to said robot body, and a teaching portion validation switch for making indication by its opened/closed state as to whether or not said deadman switch has a valid servo turning-on right;
• an external servo turning-on switch for making indication by its opened/closed state as to whether or not an external servo turning-on request is made;
• a control portion supplied with a first signal from said teaching portion, said first signal indicating the opened/closed state of said deadman switch, a second signal from said teaching portion, said second signal indicating the opened/closed state of said teaching portion validation switch, and an external servo turning-on request signal from said external servo turning-on switch, said external servo turning-on request signal indicating the opened/closed state of said external servo turning-on switch;
• and
• a changeover portion for preventing said external servo turning-on request signal from being supplied to said control portion when said second signal indicates that said deadman switch has said valid servo turning-on right.