Aux Positioner Lecture Notes

Auxiliary positioner.
Lectures
.!i

1.
2.
3.
lntroduction
Contents
Purpose, the block diagram and a principle of article operation
3
1.1. Purpose and the basic characteristics of the auxiliary positioner
1.2. Block diagram of the positioner control system
'1.3. Modes of AP functioning
The positioner description
2.1. Positioner design
Construction and operation of the positioner mechanical components
3.1. Abearingarm
3.2. The flange
3.3. Landing ring
3.4. Electromechanical azimuth drive
3.5. Electromechanical drive of the elevation axis
3.6. Angulartransducers
3.7. Instrumentation
3.8. Radome fastening
4. The positioner control sYstem
4.1. HPIB Controller
4.2. The arithmetic-logic unit
4.3. Power amplifier
4.4. Positionerangularcoordinate transducers
23
4.5. Control sYstem Power unit
5. Operation and servicing of the positioner
5.1. Preparation for mounting and mounting.
5.2. Preparation for oPeration
5.3. Coordinate transducers alignment
5.4. Maintenance service of the positioner
5.5. Positioner malfunctions and their elimination
5.5.1. Mechanical units malfunction
5.5.2. Control system malfunction
3
4
5
6
6
10
10
10
10
10
13
14
15
15
16
16
1B
22
24
25
25
25
25
26
27
27
28

Introduction
the Present description is intended for studying a design, a principle of action and
characteristics of the positioner. lt is necessary for full and correct use of technical
capacities of the article. The description consists of the following basic sections:
"lntroduction".
1. Purpose .
2. The positioner description.
3. Construction and operation of the positioner mechanical components.
4. The positioner control system.
5. Operation and servicing of the positioner.
1. Purpose, the block diagram and a principle of article operation.
The article further called the auxiliary positioner (AP) is intended for spatial orien-
tation of the object under test placed on it in order to study its radio characteristics. The
positioner enters into the complete set of the pedestal positioner-2 (PP-2) and consid-
erably expands its technical capacities. Operation of the article is carried out in the
closed, specially equipped room at an ambient temperature no more +33C, relative hu-
midity no more 90%, at temperature 20C.
1.1 Purpose and the basic characteristics of the auxiliary positioner.
AP is fixed on a faceplate of polarization axis of PP-2. The positioner is intended for the
measurement of antenna parameters. lts characteristics are the follows:
1) Quantity of controlled coordinates.:...':.:...:..'.'.... .......2
2) Range of moving:
- azimuth coordinate ....!45 1,,.
-
- elevation coordinate .. ... ...t45 l
3) the Maximal speed of movement, deg/sec... .
4) Number of the fixed speeds of movement, ,. ,.. . ! ,r )
5) Numberof digits of digital transducers .........15
6) Error of positioning, angular sec. . ... ... ... .40
7) Power supply

-frequency, Hz. .. 5011
-voltage, V.............. .....220t10%
8) Power consumption, W. ... . no more than 300 ,.,r
9) Carrying capacity, k9... .......S0..
2.1.3. Structure of the article.
The auxiliary positioner consists of the mechanical part and control system. The
control system is a rack connected with the manual control unit by cables. The me-
chanical part is connected with the control system rack by cabres.
1.2 Block diagram of the positioner control system.
. The positioner control system is a follow-up control system with two negative feed-
backs: position feedback - for maintenance of positioning of drives with required accu-
racy, and velocity feedback - for maintenance of a constancy of speed of rotation of
drive motors while movement. The block diagram of the AP control system is presented
in Fig. 1. The AP control system consists of Hlg controller, arithmetic-logic unit, man-
ual-control unit, and two channels of the movement control by azimuth and elevation.
x16 X16
,{l
Fig I Coneecwn d'ag,an
AI - Conlrol syslen
A2 - Distributtion ba\
A3 - Manual @nlrcl unil
A4 -Auxiliaty posiliml
K|- Cable
K2 - Cable MCU
K3 - Dislibution able
Each channel of the movement control consists of the power amplifier (PA), the motor
(M) and tachometer (TM), what is a velocity feedback. The power amplifier includes the
velocity former (VF), the speed controller consisting of the subtractor and pulse-width
modulator (PWM) with a protection device. The motor is connected to the PWM output.
The tachometer (TM) is the velocity-feedback transducer. The angle rotation transducer
is connected to output motor shaft by means of mechanical transition. This transducer

is a position feedback transducer.
The commands coming from the control computer (CC) by HPIB interface are decoded
by the controller. According to parameters of the accepted command the data for the
task formation at the ALU output are sent to the ALU. Then the task is transferred to the
velocity former (VF) of PA of the corresponding coordinate. ,
. Depending on the current value of coordinate and required speed of movement,
the velocity task is formed at the VF output. Then the task is sent to the subtractor input.
The velocity feedback signal from the tachometer output comes to another subtractor
port. The velocity error signal from the subtractor output comes to FWfrrf *iliit'r-'Jontrots
the work of the motor. Presence of the velocity feedback provides rotation of a corre-
sponding axis with the constant speed. During movement continuous interrogation is
made of the current coordinate value. lf the required final value of angle is attained, the
signal for the motor stopping is formed at the ALU output.
1.3 Modes of AP functioning.
The positioner operates in two modes: manual and automatic. The manual mode
is intended for check of the positioner serviceability during preventive maintenance, and
also for determination of its characteristics at certification. The positioner movement by
each coordinate is controlled from the manual control unit (MCU) or by means of the
controls located on the ALU front panel,
The automatic operating mode is the basic one at carrying out of measurements
with the help of the measuring complex, thus the positioner is controlled from the com-
puter by HPIB interface. Control commands are presented in the Annex 1 of the De-
scription.

2. The positioner description.
The positioner is an assembly of a mechanical construction with angular transducers
and the motors which are set on a faceplate of the PP-2 polarization axis and control
system (CS) connected with the control computer by HPIB interface. The equipment
placed on a mechanical construction is connected to the CC output connectors by ca-
bles dressed in metal.
2.1 Positioner design.
Positioner construction and operation.
Fig.2
elevation
/-745'
4
rJ
The positioner construction contains the following basic elements represented in Fig. 2
and 3:
pola::ization
- bearing arm (BA). .............. 1
- azimuth drive (AD) ...... B
elevation drive (ED)... ................... 10
-flange. .......11
- landing ring . . ... ...29
- angular transducers... .. .. ...2 and 9
6

Aux positioner structure.
The bearing arm 1 is fastened on the flange 11 by bolts. The AP body 8 is set in
bearings on the bearing arm 1 (Fig. 2). ln turn, the body 8 of the azimuth drive is articu-
lated by means of the lever4 and the sliding member 15 with the ED output shaft 16.
The landing ring 29 for the installation 110 (Fig. 3) is fastened on arms 5 and 7 con-
nected to the azimuth drive output shaft 18.
7

k)l
*N.
3\\'
L\
"\,1 ,tt \4-
41L// ,/ z ,/
-.t' tt'
"L -". / ,ao;,
t./
-.t.-
F\V
'r/ rl
___,.-]----
Fig.3
I \- IJ
r)
\ /c
-'F $

L Bearinq arm
2 Anqle transducer
3 Brake devi ce
4 Lever
5 Arm (brackec )
6 Azirnuth drive electric motor
7 Arm (bracket)
B Body
9 Azlmuch anqfe rransducer
l0 Elevation drive
L 1 Flange
L2 bearinq
L3 bearinq
I4 bearinq
l5 Slider
L 6 Shaft
L1 bearinq
L8 Shaft
19 bearinq
20 Screw
2L bearinq
22 Shaft
23 Flexible wheef
24 Wave qenera!or
25 Rinq
26 Coqwheel
21 bearinq
28 movable rins
29 motionless wheel
30 Bushinq
31 beffows sfeeve
32 shaft
Desisnation of elements in Fis. 2 and 3
33 bearinq
34 plate
35 bearinq
3 6 rotor
31 stator
38 screw
3 9 bodr,
40 Bushins
4L worm sector
42 worm screw
43 bodv
44 bearinq
45 qear
46 bearino
41 gear
4 8 sear
49 gear
50 bearing
51 qrnnor- nl:--g
\2 Shall /cl:qql
53 qear
54 wheef
55 bearinq
5 6 gear
51 bearins
58 qear
59 radome fasteninq device
60 bracket
6 1 bracket
62 screw
63 clamp
Moving of the positioner components in the assigned range is limited by the end
switches. The operation of the positioner electromechanical systems is adjusted with
the help of control system (CC) (not shown in Fig. 2 and 3).
The positioner operates as follows. With control signals coming, the output ele-
ments of drives namely shafts 18 and 16 correspondingly begin rotation in the specified
direction and specified mode. lt is provided with presence of transducers of position
feedback 2 and 9 and by velocity. The last ones are the tachometers placed on elec-
tric motors 6 and 9. In so doing the change of angular position of AD body 8 by means
of the lever4, the sliding member 15, arms 5 and 7 in appropriate way changes the an-
gular position of the landing ring 29 with the target.
9

3. Construction and operation of the positioner mechanical components.
3.1. A bearing arm.
The bearing arm (BA) 1 is a base element of the positioner. On the one hand BA
has a setting plate by means of which it is based on flange 11, on the other hand, it is
finished by a plug with landing holes for the setting of the body AD 8in the bearing sup-
ports.. In the BA 1 middle part the guide for the sliding member 15 and a support for the
bearing 44 are executed.
3.2. The flange
The Flange 11 (Fig. 2) is an assembly unit and is intended for the placement of
elements of the positioner construction and its setting on 23 of PP-2 (see description of
PP-2, Fig.2).
It consists of a supporting plate 51 (Fig. 3) with the holes for the fastening by
means of bolts to the faceplate of PP-2 and a glass 52 with an external landing surface
for the exact installation of the positioner with respect to the polarization axis on the
faceplate of PP-2. Simultaneously the flange serves as the elevation drive body.
3.3. Landing ring.
The landing ring is intended for the installation of researched object. lt consists
of a stationary ring 28 which is fastened to arms 5 and 7 by bolts and a movable ring 29
which is set on the stationary ring 28 using threaded joint. Fixing of the movable ring
with respect to the stationary ring is carried out by 2 bolts 20. The scale for readout of
the ring angle of rotation is put on the lateral surface of movable ring 29 (Fig. 3).
3.4. Electromechanical azimuth drive.
The drive 8 (Fig. 2) is intended for the movement of the auxiliary positioner with respect
to the azimuth axis. The drive construction consists of the direct-current motor 6 with
the inserted tachometer, position transducer BT-72 9, electromagnetic brake device 3
for the object fixation in the specified position, and three-step reducer.
The drive and its elements have the following characteristics:
:
- the maximal possible torque, Nm...... ........ 978.8
- the maximal angular speed of an output member, rev/min. ..... 1,02
10

- the general reducer gear-ratio,.,,..... ,....3899
- accuracy of positioning, sec. ...-40
Electric motor:
- type........ [n60-90-4-24P09[09 (Russian specification)
- voltage, V....... ...............24
- the maximal number of revolutions. Rev/min.. ..... 4000
- the nominal torque, Nm, .0.2150
Electromagnet:
- voltage, V....... ............24
- developed axial force. N.............. .........25
The drive is represented in Fig. 3 and its structure is the follows. The target shaft
18 is set in the body B on bearings 17 and 19. The shaft 18 is rigidly connected by one
end to an arm 5 and by another end it is connected to a flexible wheel 23. Bearings 21
and 27 are placed on the shaft 18 and in the body detail 30. The gear wheel 26 with the
generator of waves 24 of the wave transition is set in bearings 21 and 27. The wave
transition consists of a ring 25 with the internal gearing, set in the body 8 and the flexi-
ble wheel 23 rigidly connected with the output shaft 18.The gearing wheel 26 (Fig.4) is
kinematically connected with the eclectic motor 6, gear elements 53, 54, and 56. In so
doing the gear 53 is set on the shaft of the motor 6/ the wheel 54 and the gear 56 are in
the bearings 55 and 57.
11

Fig.4
The brake device (Fig. 5) consists of the body 1 with the induction coil 8. The
first brake disk 3 is set inside of the body. lts rotation is restricted by a pin 2 and it com-
municates with a spring 6 through a pusher 7, the effort of the spring is controlled by the
screw 9. The second brake disk 4 is rigidly fixed on the shaft 5. On the other end of a
shaft 5 the gear 56 is set. lt is in gearing with a wheel 54. The shaft 22 (Fig.2) of the
gearing wheel 26 is connected to the shaft 32 of the elevation transducer 9 by the bel-
lows clutch 31.
The drive works as follows. Without control signal, the disk 3 under the influence
of the spring 6 is in power contact to the disk 4 that provides the fixation of the gearing
wheel 26 (Fig. 4). With a signal to start movement, the current is applied to the winding
of the induction coil 8 of the brake device. In so doing the disk 3 moves and com-
pressed the spring 6 and releases the disk 4 (Fig. 5).
T2

I
Fig.5
2). The torque from the electric motor 6 is transferred to a target shaft 18 (Fig.
2,3) by the kinematical circuit including elements 53,54,56, 26.25,24, and 23. lt pro-
vides the movement of the arm 5 and 7 with a landing ring 29.
The specified angular position is provided with the position transducer 9 which is
set on the body of a reducer 8 and is rigidly connected to the shaft 22 of the gearing
wheel 26 (Fig. 3).
3.5. Electromechanical drive of the elevation axis.
Drive 10 (Fig. 2) is assigned for the movement of the body of the reducer 8 of
the azimuth drives. Thus moving of a landing ring 29 with AP with respect to the eleva-
tion axis is attained (Fig. 3).
The drive and its elements have the following characteristics:
:
- maximal torque of the output shaft, Nm.... ... 4,59
- reducer gear-ratio ..... 18.2
- accuracy of positioning, sec. ........40 "
Electric motor:
- type ....... An60-90-4-24P09809
I
(Russian specification)
- voltage, V............. .....24
- the maximal number of resolutions. Rev/min. .... 4000
I3

- the nominal torque, Nm.... 0.2150
Structurally the drive consists of the electric motor 10, a two-level cylindrical re-
ducer which body is the flange 11, screw - nut transition with the lever 4, hingedly con-
nected to the AD body 8 (Fig. 3), and the transducer of angular position 2 (Fig. 2). The
output shaft 16 executed as a screw, is set in bearings 12,13, 14, and 44 on the bear-
ing arm and the flange 1 1. lt is kinematically connected with slider 15 forming the screw-
nut transition. The slider 15 is restricted from the rotation and by one side moves along
the base guide. The output shaft 16 is kinematically connected to the electric motor 10
through the two-step cylindrical reducer consisting of gear elements 45,47,48,49 set in
bearings 46,50. The transducer of the angular position 2 is placed in the body which
construction is unified for all drives.
The drive works as follows. According to the CC command the torque from the
electric motor 10 is transferred bythe kinematical circuit including elements 49,45,48,
47,16,15and4. ltprovides movementinthespecifieddirectionandwiththespecified
speed of the body of reducer B of azimuth drive. It allows making the object under test
moving with respect to the elevation axes.
With set position attained by the slave unit of the drive, what is fixed by angular
transducer 2, the motor 10 is disconnected.
3.6. Angular transducers.
. Angular transducers (AT) 2 and 9 (Fig. 2-3) provide the movement feedback
with respect to azimuth and elevation axes. All transducers have the built - in rotating
transformer BT -71 (Russian abbreviation) in the base.
. The construction of the angular transducers is based on the bearing body 39, in the
boring of which the bushing 40 is disposed. The stator 37BT (Russian abbreviation) is
placed on the bushing 40. The bushing 40 is fastened to the body 39 by screws 38.
The angular movement is possible within the limits of grooves. The rotor 36 BT (Rus-
sian abbreviation) is fixed on the output shaft 32 with the help of plates 34 and rotates in
bearings 33 and 35, which are placed in boring of the body 39.
Worm sector 41 is rigidly connected to the bushing 40. lt communicates with a
worm 42 set in the body 43, rigidly connected with the bearing body 39. The worm pair
41 and 42 is intended for setting of "zero" of the transducer which is carried out as fol-
lows.
To coordinate initial "zero" position of the positioner executive elements and AG
indications it is necessary to remove a cover and to weaken screws 38 up to make pos-
sible free rotation of the bushing 40 with stator 37 with respect to the body 39. Rotating
T4

the worm 42 one should attain the angular position of the stator 37 with respect to the
stationary rotor 36 which corresponds to "zero" position of BT-71. After that the bushing
40 should be fixed by screws 38 and set the cover.
3.7. Instrumentation.
The following instrumentations enter the structure of the given article:
angular movement transducers .,, ,,... Rotating transformers BT-71
speed transducers ............ built - in tachometers of electric motor
In60-90- 4-24P 09 809 (Russian specification)
Basic specifications and characteristics of instrumentations are presented in certificates.
3.8.Radome fastening.
The device for radome fastening is set on the flange 11. lt consists of 4 bearing
arms. Each bearing arm has two height- and length-controlled bearing arms 60 and 61.
To fix the radome on the fastening device the screw 62 with movable clamp 63 is used,
In addition, the positioner is supplied with radome fastening device.
15

4. The positioner control system
The control system (CS) is the block in which control unit and power supply unit
are disposed.
The connectors are disposed on the unit rear panel. They are used to connect
the positioner drives and transducers to the control system by cables.
Schematic electric diagrams of cables and AP are presented in the Annex.
The control system consists of the following units: HPIB controller, the arithme-
tic-logical unit, two blocks of transformation of the output signals of angular transducers
(phase-code transformer - PCT) and two power amplifiers. Transducers of the input al-
ternating voltage to direct current voltage are located in the power unit. Schematic elec-
tric diagrams of control system units connections are presented in Annex (400.01.12 )
4.1 HPIB Controller.
HPIB controller is used to provide the communication between the control com-
puter and the positioner control system through HPIB interface.
The controller provides reception of control commands of a corresponding for-
mat, decoding of commands, transformation of data, formation of control signals and
data transmission to control systems, control algorithm realization by positioner accord-
ing to the accepted commands, reading of the information from transducers of control
systems and transfer of the received information to the control computer The controller
realizes the following HPIB interface functions determined by standard IEEE-488:
1. Source Handshake 1(SHl);
2. Acceptor handshake 1 (AH1);
3. Listener (13);
4. Talker (T5);
5. Service request 1 (SR1);
6. Device clear (DC1).
In so doing the following interface messages are processed:
1. Talker address (TAD);
2. Listener address (LAD);
3. Serial poll enable (SPE);
4. Serial poll disable (SPD);
5. Device clear (DCL);
16

6. Selected device clear (SDC);
7 Unlisten (UNL).
The Controller is a microprocessor device that operates according the code writ-
ten in ROM. The electric schematic circuit of the controller is shown in the Annex 2-1.
With power switched on, the initialization of the controller is realized according to
the program which includes the reading of the address setter on switches and indication
of the address of the HPIB bus controller on the front panel, programming of a microcir-
cuit of the HPIB interface controller and processor timers, an output of signals "Stop" to
the drive motors. Then the controller turns to the standby mode waiting for the com-
mands from the control computer.
The commands accepted by HPIB interface are decoded by the required algo-
rithm of the control system processor operation is realized according to the program.
Data exchange by HPIB bus is realized according to HPIB report at a hardware level of
the interface microcircuit. HPIB controller commands allow realizing the following posi-
tioner functions:
1) installation of coordinates of the positioner drives in any position from the
specified angular range;
2) scanning of coordinates with simultaneous measurement in the set points.
Movement can be carried out with one of four preset speeds Trajectory of scanning are
the following: linear nine-by-line with change of the movement direction by azimuth and
elevation axes,
3) measurement of the current values of all coordinates. lt is carried out by
means of a special command according to which the controller polls all coordinate
transducers and forms the target buffer in HPIB symbolic-coding format. With control-
ler addressed to transition the controller transfers the measured values to the computer.
The description of commands of controller computer are presented in the Annex 1-2.
With operation of the controller, its status is fixed in the status byte which is dis-
played on the controller front panel and the computer can read out the data in the proc-
ess of serial poll. With error situations during controller RAM operation, the error type
and its code is written into the special error stack organized according to the LIFO prin-
ciple. The error type is simultaneously written in the status byte. Each bit of the status
byte may cause inquiry on service, but can be disguised by a special control command
from the control computer. Error reading is also realized by means of a special com-
mand.
T7

the Annex .
The description of the controller message codes of and errors are presented in
At measurements in the scanning mode with measuring equipment starting di-
rectly from control system the "START" signals are formed on the controller plate by
special former controlled by the controller processor. Duration of a pulse is soft defined
and is equal to 7 mcs. Polarity of pulses is positive.
4.2 The arithmetic-logic unit.
Arithmetic-logic unit (ALU) is intended for the calculation of 16-digit binary code
(in view of a sign) of a difference between the task for movement and the value of a
code of the feedback transducer. The code of the transducer is read out from PCT. The
received code of the difference for each coordinate (azimuth or elevation) is sent to the
power amplifiers, which are carrying out drives control.
ALU has two operating modes:
- Automatic control;
-Manual control.
ln automatic operating mode ALU calculates the difference for each of coordi-
nates by multiplexing in time of the moments of the information processing, which are
determined by the control signals former. The task for movement and movement control
(Start / stop) by each coordinate is carried out by the HPIB controller (CHPIB) according
to the commands received from the control computer and algorithms of the control sys-
tem functioning.
In a manual operating mode each coordinate control is carried out by means of
the controls located on the ALU front panel, or on the manual control unit (MCU). Basic
electric schematic diagram of ALU is presented in the Annex 2-2. Basic electric sche-
matic diagram of MCU is presented in the Annex 2-6.
Functionally ALU of the auxiliary positioner control system corresponds to the
ALU of PP-1 and PP-z.
The positioner control in a manual operating mode is carried out with the help of
the ALU front panel. The schematic diagram of the front panel is presented in the An-
nex .
ALU front panel is a microprocessor controller realized on microcircuit AT89C52
what is different from ALU of PP-1 and PP-2. Buttons START and STOP. the switch of
operating modes, buttons of the coordinates and speeds task setting, and the toggle-
switch of inclusion MCU are connected to the microprocessor. To display the value of
18

the task on the chosen coordinate and a number of velocity, there are indicators on the
ALU front panel.
In automatic control mode the switch "MODE" is in position "HPlB". In this case
the message "HPlB" is output on indicators and controls of the front panel are blocked.
In manual mode (the switch "MODE" is set in positions 1,2,3) the process is controlled
by only one chosen coordinate using the front panel of ALU ("Start ", "Stop").
The task on the chosen coordinate is set digit-by-digit. The digit of the specified
value is chosen by consecutive pressing of button "SELECT", and the value of the cho-
sen digit is chosen by pressing the button "SET". Simultaneously the binary code of the
task is byte-series output and it is written in memory registers of the ALU main plate.
Beside that the signal of 200 KHz frequency is constantly formed at the output
of the microprocessor on the front panel which necessary for operation of the ALU pulse
distributer.
Manual control mode is carried out with the help of MCU with switch-on of the
toggle-switch on the ALU front panel or the similar toggle-switch on MCU. ln this case
switch-on of drives, a choice of speed and a direction of movement is realized by MCU
controls.
Schematic electric diagrams of manual control unit and its cables are presented
in Annex (400.01.10 ED and 400.01.15 ED)
4.3 Power amplifier.
The power amplifier (PA) is used to form the control voltage at the motor. The
constancy of speed of the drive rotation is provided according to a negative velocity
feedback. The signal of the feedback is formed at the tachometer output.
The following elements are located on the power amplifier plate: the (VF), veloc-
ity controller (VC), power-width modulator (PWM), and protection devices. The electric
schematic diagram of the power amplifier is presented in Annex .
Resistor (current sensor) is inserted in the bottom general point of the bridge.
Voltage loss on the resistor is an input signal for the scheme of protection. With voltage
increase on the resistor, the scheme of protection operates, and the motor is discon-
nected. A light-emitting diode "Overload" is lit on the PA front panel. To restore service-
ability of the amplifier it is necessary to remove the reason of the overload of the motor
and to press button " RESET " on the PA front panel.
4.4 Positioner angular coordinate transducers.
Rotating transformers such as BT-71 (Russian abbreviation) with phase-code
t9

transformers (PCT) serve as transducers of angular values. Signals of sine shape from
PCT come to the BT-stator windings.
The axis of rotor BT is mechanically connected to a corresponding positioner axis
of rotation. With a turn of the BT rotor, the phase of output signals of the measuring
windings located on a rotor, changes proportionally to the angle of rotation. PCT trans-
forms the value of a phase into the1S-digit digital code which is delivered to the ALU da-
tabase bus, general for all PCT,
PCT are bought articles and their principle of action, and also the order of opera-
tion is presented in the PCT Description.
4.5 Control system power unit.
Control system power unit is intended for the formation of the feeding voltage
necessary for functioning of the control system. The basic schematic diagram of the
power unit is presented in Annex.
The unit is placed in the CS rack.
The unit consists of the following voltage transformers:
- AC/DC of 5-25-5 type for feeding of control system logic devices;
- AC/DC of 5-320-24 type for feeding of motors power circuits;
- DC/DC of DKE15B-15 type for feeding of operational amplifiers.
Parameters of transformers are presented in Table 2
Type Input voltage
(v)
Table 2
The toggle-switch "Power supply" and indicators of feeding voltage are located
on the front panel of the power unit.
Output volt-
age (V)
Output cur-
rent (A)
s-25-5 AC 200-240 DC5 5
s-320-24 AC 200-240 DC 24 12.5
DKE15B-15 DC 18-36 DC t15 r0.500
20

5 Operation and servicing of the positioner.
5.1. Preparation for mounting and mounting.
Articles are delivered to a place of operation knocked-down in transport package.
Before assembly and installation of the article on PP-2 it is necessary to make
sure of availability of positioner units in accordance with the description.
Before assembly it is necessary to make sure in absence of external mechanical
damages, and also to remove a layer of protective greasing from surfaces of units and
details of the article. The order of positioner installation and assembly is defined by the
correspond ing description,
Article mounting, its movement from a place of mounting to the working zone,
and also its installation in the specified position is carried out on a rail way. After the
positioner assembly it is necessary to test its conformity with parameters of the techni-
cal project according to the technique.
5.2 Preparation for operation.
Positioner preparation for work is carried out in the following sequence:
- to set the auxiliary positioner on the PP-2 faceplate;
- to prepare PP-2 for operation according to the instruction on PP-2;
- to set and fix PP-2 by screws 28 and 50 in a working position;
- to earth bodies of control systems of PP-2 and AP;
- to connect the cable system PP-2 to the PP-2 control system, AP cable system
to its CS and to make sure in a manual mode in execution of commands on movement
by both coordinates within the limits of the set ranges, presence of feedback signals,
and operation of end switches.
HPIB cable.
Connect auxiliary positioner control system with the control computer by the
ATTENTION:
1. All connections of control systems with control computer, AP, and
PP-2 must be carried out when the power is switched off.
2. lt is strictly prohibited to switch on the control system of AP and
PP-2 when the angular transducers are disconnected!
21

5.3 Coordinate transducers alignment
Positioner coordinate transducers alignment is carried out on a working position
in the following sequence:
- connect control system to the positioner;
- switch on CS and to set the manual operating mode;
- serially setting value 16384 on ALU front panel for each coordinate, put coordi-
nate axes in the given position;
- check if this position of axes is correct ( elevation and azimuth equal to zero)
by means of geodetic devices;
- in case of a deviation of axes position from zero to set coordinates in zero po-
sition by means of the manual control unit without changing values on ALU switches;
- attain a zero mismatch on the PA indicator by means of a worm gear of the cor-
responding coord inate transducer.
5.4 Maintenance service of the positioner.
Maintenance of positioner mechanical systems is carried out in the place of in-
stallation by the maintenance personnel supervising the work of the setup and ac-
quainted with the specifications on the structure and operation.
In connection with design features of the positioner, repeatedly-short-term oper-
ating mode of its executive mechanisms and conditions of operation, the maintenance
service providing it normal functioning is carried out as preventive actions. These ac-
tions include testing of absence of external mechanical damages, presence of greasing
on open surfaces of executive and regulating devices' transmissions.
It is necessary to control the presence of consistent greasing on surfaces of a
screw gear 15 and 16 of elevation drive, guide 1, slider 5 (see Positioner description,
Fig. 3). Presence of consistent greasing in closed bearing units according to conditions
of delivery provides their normal functioning during all term of operation if conditions of
operation are observed.
It is necessary in one year of operation to replace greasing of tooth gearings of
the first and second step of a reducer. In so doing complete disassembly and washing
of gears are conducted. Tighten bolt and screw connections.
AP control system maintenance is not required.
22

5.5 Positioner malfunctions and their elimination.
5.5.1 Mechanical units malfunction.
Malfunctions Possible cause Way of elimination Comments
Amplified noise in
a reducer
Motor nonuniform
rotation,
works with noise,
overcurrent protectionperiodi-
cally operates.
Failure of the azi-
muthal drive brake
device. Motor
hardly rotates.
Incomplete range
of moving of end
switches
Discrepancy of in-
dications of the an-
gle transducer and
Wave generator,
flexible wheel of
wave transmission
is disabled
1. Significant me-
chanical resistance
in kinematic circuit
a)absence of lubri-
cant;
b) presence of dirt;
c) bearing disabled
2. Braking device
malfunction
Excessive preliminary
tightness of
the brake spring.
Wrong installation
of end switches.
Discrepancy of set-
ting of "zero" position
of the angle
Replace wave
transmission
l.Rearrange drive
kinematic circuits
2. Set the gap no
less 0.5 mm be-
liminary tightness of
spring 6, thus to
unscrew the screw
9 by 1,0-1,5 revolu-
tions and to fix it by
counternut
iee positioner ser-
vicing
See positioner ser-
vicing
See positioner ser-
vicing, Fig.4
tween disks 3 and 4
To reduce a pre- See positioner ser-
To make adjust-
ment of a range of
operation of end
switches
To carry out setting
of "zero" of the
transducer
vicing, Fig. 4
iee positioner ser-
vicing,
ZJ

the angular position
of the corresponding
positioner ele-
ment
. Motor rotates at
small and average
speeds, adjustment
of speed is not real-
ized.
Rotation of mobile
landing ring 29 with
respect to mo-
tionless ring 28 is
difficult
transducer
1 Pollution of ta-
chometer collector
or the motor
2. The pulsation of
tachometer target
signal exceeds al-
lowed values
Mechanical dam-
ages of groove,
incomplete fixing of
rings by bolts 20,
pollution of a
groove ls compli-
cated, absence of
greasing
5.5.2 Control system malfunction.
1. To clear
collectors of a dust,
to wash out by
gasoline or spirit
2. To replace
the motor with ta-
chometer
Remove failure,
unscrew bolts 20,
To clear screw joint
of a dust, to grease
it.
lee positioner ser-
vicing, Fig.2
Malfunction Possible cause elimination comment
At any command 1) electronic protection ol To do away the arisen
and any mode the the target cascade has reason of an overload:
motor does not ro-
tate, the mismatch is
displayed.
operated
2) Malfunction of ele-
ments of the permission
signals former
3) chip of power amplifier
output cascade ls plate
faulty
presence of short cir-
cuit in circuits of an an-
chor or jamming of a
drive.
2,3) To replace PA
24

At start-up of the
motor the indicator
on ALU lights, the
4) fixation switch 1 ls
faulty.
mismatch is not dis- braking by resistor R151
played, the motor on PA plate
does not rotate.
Big error of position-
ing
Wrong positioning ol
drive
CS does not accept
commands of control
computer, no
Malfunction of the AP
signal former
To increase a zone of
4) To clean contacts o1
lhe switch
1) To replace PA plate
1) Small zone of braking 1) Increase zone ol
braking by resistor
1) Malfunction in a circuit
of reading of a code of
coord inate transd ucers
synchronization of face chip is faulty.
HPIB controller.
AII control computer
1) Bus formers of HPIB
controllers are faulty
2) HPIB controller inter-
commands are ac- chip is faulty.
cepted with error.
lncorrect command
name.
1) HPIB controller
R151 on PA plate.
1) To replace corre-
sponding block posi-
tioner CS OPU
2) ) To replace ALU
plate
1) Replace HPIB con-
troller plate.
2) Replace chip DD18
on HPIB controller
plate.
1) Replace chip DD17
on HPIB controller
plate.
25

Auxiliary positioner.
Lectures