U Page 42
Digital controller RK 4004
.5.8. dyn. currentfactor
.5.9. term. timeconst.
.6.0. limited current
This time-limited excess current is used to increase the dynamics of
the DC actuator drive (shorter acceleration time)
For a short time a DC actuator drive may be operated with a higher
motor current. The factor is determined here. The internal current li-
mit is calculated on the basis of the nominal motor current in parame-
ter ".5.7. motorcurrent" and the factor from parameter ".5.8. dyn. cur-
rentfactor". The duration of the excess current is set in parameter
".5.9. therm. timeconst.".
Excess current functions according to the following principle:
Current
in mA
Time
in s
motor current
internal cur-
rent limit
nom. motor current
Pos. 1
Pos. 2
actual permissi-
ble motor cur-
rent
If the motor current input is less than the nominal motor current the
permissible motor current will be increased within the set time (.5.9.
term. timeconst.) to the internal current limit. This actual permissible
motor current is displayed in parameter ".6.0. limited current".
If the motor current input (pos. 1) is greater than the nominal motor
current (.5.7. motor current) the permissible motor current will then
be reduced again within the set time (.5.9. term. timeconst.) to the
nominal motor current. As soon as the motor current is again drops
below the nominal motor current (pos. 2) increasing of the current li-
mit is resumed.
Once the operating voltage is supplied the permissible motor cur-
rent begins at the nominal motor current.
The current limit is upwardly limited by the maximum output stage
current (see technical data).
.6.1. act. current
The actual motor current of the DC actuator drive is displayed.
