31
MICROSPEED
REV 04/05
RCA resistor
It will be mounted on the socket pin 3-
22, to compensate for the voltage drop due to the
motors internal resistance.
To calculate it,use this equation:
Use a resistor of 56 Kohm or the higher value.
RCA (kohm) = 0,5 x 4000 x 50 =200 Kohm
10 x 20 x 2.5
Example:
Drive 10/20 A ,
Ri=
2.5 ohm
If,after this procedure the motor is unstable increase
the value by using the next (higher) commercial value
avalaible.
RCA (k ohm) = 0,5 x n Ke
Vref Ipk Ri
WHERE:
n= max. speed expressed in rpm.
Ri=Total motor resistance with brushes.
Ipk =Peak current, (size)of the drive.
Ke=Sevomotor BEMF at 1000 rpm.
Vref= Max voltage reference.
