K
v
1/K
e
(ST
m
+1)(ST
e
+1)
1
S
V
E
W
VOLTAGE SOURCE
P
K
a
K
t
JS
1
S
V
I
W
CURRENT SOURCE
P
1
S
V
W
P
VELOCITY LOOP
1
K
g
(ST
1
+1)
Figure 10.6 - Mathematical model of the motor and amplifier in three operational modes
Encoder
The encoder generates N pulses per revolution. It outputs two signals, Channel A and B, which
are in quadrature. Due to the quadrature relationship between the encoder channels, the position
resolution is increased to 4N quadrature counts/rev.
The model of the encoder can be represented by a gain of
Kf = 4N/2
π
[count/rad]
For example, a 1000 lines/rev encoder is modeled as
Kf = 638
170
•
Chapter 10 Theory of Operation
DMC-1600
