Learners examine the circuitry in a DC variable speed drive that prevents the motor from running at 0 rpm or at maximum speed under certain conditions.

In this animated activity, students read about the two general types of variable resistors: potentiometers and rheostats. A brief quiz completes the learning object.

In this animated activity, students read about the two general types of variable resistors: potentiometers and rheostats. They then answer six multiple-choice questions.