SERVO DEVICE

PURPOSE:To give the servo characteristics without fluctuation of angle even if an external disturbance is applied, by operating a difference between an output of an integrator and a speed signal proportional to the rotating speed of a motor and inputting the output to a servo amplifier. CONSTITUTION:When the external disturbance torque such as a wind is applied to a radar antenna 10, an instantaneous angular error signal 4 is produced, but since the signal is integrated at an integrator 13 via a position amplifier 5 and a speed error operating device 6, when the output of the integrator 13 reaches an amplitude corresponding to the inverting torque, the signal 4 reaches zero. Since the signal for the generation of the inverting torque is not generated at a stage before the integrator 13, the directing angle of the antenna 10 is matched to a reference angle. Further, an error amplifier 14 prevents the servo system from being unstable due to the integrator 13.