Specifications

NOTE
Linkage installation described in this section
of the manual is for direct acting power
positioners.
a. Characterized Linkage System.
1. Make Sue. a linear cam is installed to get
linear outputs from power positioner.
2. Figure out how far vertically the operating
lever travels using Figure A-2 and the
following equation:
E
Figure A-2. Vertical Arm Travel
NOTE
The following known values are wed to
calculate the vertical distance travelled by
the drive lever; “Y”.
R, = Length of drive lever (from shaft
center to clevis pin center) measured
in inches.
e1 = Total angular rotation of drive lever.
If power positioner is at full stroke,
tbk measurement is So”.
PI = Angular measurement of drive lever
from vertical centerline with piston
fulIy extended.
To perform the following procedure, a
calculator with basic functions, plus the
following scientific functions, is necessary:
-Sine Function (SIN)
-Square Function (x’)
Use the following procedure to determine Y,
the vertical distance travelled by drive lever:
(a) Add value of 8, to value of PI.
(b) Divide answer from step (a) by 2.0.
(c) Enter answer from step (b) and press
sine. key (SIN).
(d) Press square key (x2).
(e) Multiply answer from step (d) by
length of drive lever (R,).
(f) Multiply answer from step (e) by 2.
(g) Write down answer from step (f) and
label it (f) for use later on.
(h) Clear calculator.