Galil DMC-1510 - Encoder

138 • Chapter 10 Theory of Operation DMC-1500
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
K
f
= 4N/2π [count/rad]
For example, a 1000 lines/rev encoder is modeled as
K
f
= 638
K
v
1/K
e
(ST
m
+1)(ST
e
+1)
1
S
V
EWP
VOLTAGE SOURCE
K
a
K
t
JS
1
S
V
IWP
CURRENT SOURCE
1
S
V
WP
VELOCITY LOOP
1
K
g
(ST
1
+1)