Selema 65 - Page 30

30
Service Manual
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DC 4Q A Series
RCA resistor calculations
RCA (Kohm) = 0,49 * 1000 * Vmot
Vref * Ipk * Ri
Example: Drive 7/14A, Ri=0,3ohm, Vmot=36V, Reference=10V
Calculate:
RCA (Kohm) = 0,49 * 1000 * 36 = 420K
10 * 14 * 0,3
Insert a 470Kohm resistance. If after insertion of the resistor the motor is unstable, increase the
Resistance value of RCA.
Where:
Vmot= Nominal voltage of the motor
Ri=Max. cold motor resistance.
Ipk =Peak drive current.
Vref= max. applied reference voltage in VEL
Insert an RCA resistor on the header (ajustement zone) to compensate for voltage loss due to the
motor resistance reducing the loss of RPM.
The formula is as follows:
Setting for Brush motor with armature (Continue)