12

ATA6830

4575C–BCD–05/03

Figure 11. Dynamic Frequency Adaption

In addition to the actual step frequency there is a maximum step frequency up to which

the actual step frequency can rise. To secure a correct operation at low supply voltages

the maximum value for the stepping frequency is smaller at low voltages. If the supply

voltage falls below the 9 V threshold, travel operation will suspend. To restart operation,

the supply voltage has to rise above 10.5 V. The relation of the maximum step fre-

quency and the supply voltage during operation is shown in Table 4.

Table 3. Frequency Ramp

Number

Step Frequency (Hz)

Step Time (µs)

1

303

3300

2

345

2895

3

394

2540

4

446

2240

5

493

2030

6

538

1860

7

575

1740

8

613

1630

9

649

1540

10

680

1470

11

714

1400

12

741

1350

13

769

1300

14

800

1250

15

826

1210

16

855

1170

17

877

1140

18

901

1110

19

926

1080

20

952

1050

21

980

1020

22

1000

1000

frequency

present position

nominal

position

time t+1

nominal

positon

time t

present

frequency

minimum

frequency

(300 Hz)

position