E L C O p e r a t i o n M a n u a l
F o r m o r e i nf o r m a t i o n v i sit :
w w w. e a t o n . c o m
MN05003006E
4-2
4.1 ELC
Series
4.1.1
ELC-MC01
4.1.1.1 The Concept of a Servo Drive System
The speed and positioning control of the step or servo drive system are typically applied to a system
requiring accurate control to transmit power. The servo drive system receives pulse instructions,
pulses and frequency to control the angle and speed of the rotation of motor. See the configuration
of the system below.
AC
DC
AC
DC
Filter
Power input
Servo drive
Instruction
pulse
fo
Error counter
Servo motor
Encoder
Position controller
The instruction pulses are brought into the error counter via the electronic gear. The error counter
counts the number of pulses and compares the pulses with the feedback pulses from the encoder.
Then it adjusts the rotation speed of the servo motor until the frequencies of both streams of pulses
are equal. The number of pulses and the frequency of pulses sent by the position controller are
based on the equipment determined by the servo drive system and the speed or position
determined by the application. See the figure below for the relationship between the equipment
parameters and instruction pulses.
Pr
fo
P
B
No
Vo
Moving platform
Servo
motor
Magnifying
servo signals
Position
controller
Deceleration
ratio
Encoder
Equipment parameters:
P
B
: Screw pitch
1/n: Deceleration ratio
△
S: Linear movement of the working object for 1
revolution of the motor
n
1
×
P
=
Δ
S
B
