Stepper motor basics

AN4158

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DocID023635 Rev 2

Figure 3. Magnetic field directions in full step and half step driving modes

Mixing the above mentioned two full step driving modes, half step driving is obtained. In half

step driving the stator magnetic field is rotated by 45° at a time (i.e.: half of the full step

rotation) and the resulting rotor movement is half of that obtained using full step driving.

Table 3 summarizes the driving sequences for the different driving modes.

Table 3. Driving sequences

Full step 1ph on

(wave driving)

Full step 2ph on

(normal driving)

Half step

Phase A

current

Phase B

current

Stator magnetic

field position

1

1

Positive

Zero

1

1

2

Positive

Positive

1a

2

3

Zero

Positive

2

2

4

Negative

Positive

2a

3

5

Negative

Zero

3

3

6

Negative

Negative

3a

4

7

Zero

Negative

4

4

8

Positive

Negative

4a

Phase A

Rotor

Phase B

1

2a

3a

4a

1a

4

3

2

NS

Stator phases

AM15105v1