Two-Phase Steppers Contain Optical Encoder

The PK Series two-phase stepping motors with an optical encoder are now available as standard (1.8°/step) or high (0.9°/step) resolution models. The PK264 (1.54" stack length) and the PK266 (2.13" stack length) use a 200 pulse-per-revolution or 400 pulse-per-revolution optical encoder to provide the feedback signals to verify step position. Holding torque values for the PK264 models reach 54.1 oz-in. The longer PK266 models produce holding torques of 124 oz-in. Overall motor axial length with the optical encoder is 2.26" for the PK264 models and 2.83" for the PK266 models. The two-channel optical encoder requires the use of pull-up resistors of 2.7 kiloohms in order to minimize output pulse rise time. The typical properly installed encoder errors for phase error and position error are 2° electrical and 10 arc-minutes respectively.