INTRODUCTION
I-P88-24A1
2 - 1
SECTION 2 - DESCRIPTION AND OPERATION
INTRODUCTION
This section describes and explains the functional and physical
operation of Type AV3 and AV4 positioners. Figure
diagrams
operating principles of the positioners. Figure
shows the
placement of a Type AV positioner in a typical system.
Figure 2-1. Type AV3/4 Positioner Operation Diagram
PILOT VA LV E
C A M
S IG N A L
D IA PH R A G M
D IA P H R A G M
F O R C E
R A N G E
S P R IN G
F O R C E
R A N G E SP R IN G
4-20 m A
O R
PU LSE SIG N A L
T 02 0 00 A
G A IN
H IN G E
S P R IN G
BA LA N C E B E A M
SIGN A L P R ES SU R E
3-15 PSIG
EM I/E L EC T R O N IC S
A N D
SE R VO
AS SE M B LY
SU PP LY P R ES S U R E
TO AC T UATO R
O 2
S
O 1
TO AC T UATO R
Figure 2-2. Block Diagram of a Typical Control System Utilizing a Positioner
+
–
+
–
SE T
PO IN T
+
–
C O N T RO LLE R
PO S IT IO N
T R AN S M IT T ER
(O P T IO N AL)
PO S IT IO N E R
AC TUATO R
PR O C ES S
O U T P U T
LO A D
T 00 7 70 A
L IN K AG E
P RO C ES S F E E D B A C K