Revised duty cycle calculations using the four-parameter thermal model.

The article focuses on the revised UL1004 electric motor standard issued by Underwriter Laboratories Inc. (UL), which recognizes that servo and stepper motors output peak torque intermittently. It states that electric motor manufacturers are required to publish both a continuous safe operating area (SOAC) and intermittent torque-speed curve for servo and stepper motor. It explores the calculation of dynamic winding temperatures while preventing the windings from exceeding maximum temperature.