Stepper motor drive modes: In a full-step sequence, two coils (phases) are typically energized simultaneously; however, claiming this “always” causes 30° per step is inaccurate for common motors. Assess the statement.

Introduction / Context:Full-step and half-step modes are standard in stepper control. In full-step, many drivers energize two phases simultaneously to maximize torque. The actual mechanical step angle, however, depends on motor construction and pole count, not merely on the drive mode.

Given Data / Assumptions:

• Statement asserts two points: (1) two coils energized in full-step and (2) “typically” 30° per step.
• Common stepper types: 1.8° (200 steps/rev), 0.9°, 7.5°, and others.
• Electrical sequence can be one-phase-on or two-phase-on; both are considered full-step styles.

Concept / Approach:While two-phase-on full-step is common, the word “always” is too strong because single-phase-on full-step also exists. More importantly, the claim about 30° per step is not representative of typical steppers used in instrumentation and robotics. A 30° step implies only 12 steps per revolution, which is atypically coarse; mainstream steppers use much finer resolution like 1.8° per step.

Step-by-Step Solution:Evaluate coil energization → often, but not always, two coils are on in full-step.Evaluate step angle → determined by motor design; common values are far below 30°.Therefore the compound statement is not generally true.

Verification / Alternative check:Vendor datasheets (NEMA 17/23) list 1.8° or 0.9° step angles; historical PM steppers list 7.5°; 30° is a special case, not “typical.”

Why Other Options Are Wrong:“Correct” overgeneralizes. “Correct only for 12-step motors” narrows it but the prompt claims typical, which is inaccurate. Drive topology (unipolar/bipolar) doesn’t fix a 30° angle. Supply voltage doesn’t set step angle.

Common Pitfalls:Confusing drive mode with mechanical resolution; assuming any motor’s step angle from the sequence alone.

Final Answer:Incorrect