PURPOSE: To supply stable electric power to a programmable controller even if the external power output circuit of the programmable controller short- circuits.

CONSTITUTION: An output circuit for external control equipment which is branched from one power source 1, which the programmable controller is equipped with, through an overcurrent detector 3, is provided with a switching element 11, and its circuit is provided with a voltage detector 4, and the programmable controller is equipped with a 1st logic circuit 5 which inputs the output of the voltage detector 4 and the output of the overcurrent detector 3, an off-delay timer circuit 8 and a timer circuit 7 which input the output of the 1st logic circuit 5, and a 3rd logic circuit 10 which inputs the output of the timer circuit 7 passed through a 2nd logic circuit 9 and the output of the off-delay timer circuit 8, and turns on and off a switching element 11 as many times as specified in case of a short circuit while securing the voltage of the programmable controller by inputting the output of the 3rd logic circuit 10 the switching element 11.