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A MICROWAVE POWER
CONTROLLER for a
RADIATION BIO-EFFECTS
EXPOSURE FACILITY
\
O)
ENVIRONMENTAL PROTECTION AGENCY
Office of ResearcK and Monitoring
-------
A MICROWAVE POWER
CONTROLLER (or a
RADIATION BIO-EFFECTS
EXPOSURE FACILITY
by
JOSEPH S. ALI
Twinbrook Research Laboratory
12709 Twinbrook Parkway
Rockville, Maryland 20852
JUNE 1972
ENVIRONMENTAL PROTECTION AGENCY
Office of Research and Monitoring
Wasliin^ton,D.C. 20460
-------
DISCLAIMER
The mention of commercial preparations or
products in no way constitutes endorsement
by the U.S. Environmental Protection Agency
or its affiliates.
-------
FOREWORD
Members of the Engineering-Physics Section at the Twinbrook Research
Laboratory have designed and installed a device that controls and moni-
tors the environmental parameters of an animal exposure chamber and
detects and measures physiological responses of the subject during micro-
wave exposure. The system includes a double-walled lucite sphere that
serves as the exposure chamber which is located within an anechoic
chamber; an atmospheric conditioning unit that supplies a predetermined
mixture of atmospheric gas to the exposure chamber under specified con-
ditions of humidity, temperature, and velocity; a 2450 MHz microwave
exposure source; a laboratory built microwave power controller; and a
laboratory computer with auxilliary equipment that controls the system
automatically and records the subject's physiological responses for
subsequent analysis.
/
Experience has shown that normal line voltage fluctuations cause
errors as great as 20% in the microwave power being delivered to the
subject and thus reduce the validity of the experimental results.
The microwave power controller that was designed and built to over-
come this source of error is described in this report. The rational:
for its design, the parts used, and the circuits are discussed.
The system is modified as requirements change and as operational
data become available. Additional information concerned with design
of irradiation systems and the biological effects of irradiation is
sought on a continuing basis. The comments of individuals interested in
this system or with other aspects of radiation protection of man and
his environment are solicited.
E. Regnier, Ph.D.
Acting Director
Twinbrook Research Laboratory
111
-------
TABLE OF CONTENTS
Foreword iii
Abstract yii
Acknowledgments viii
Introduction 1
Description 3
Theory of Operation 7
Operational Experience 14
APPENDIXES
A. Wiring Diagrams, Schematics and Parts Identification
for Microwave Power Controller 15
B. Electrical Parts List for Microwave Power
Controller 31
FIGURES
1. Block Diagram of the 2450 MHz Irradiation Facility 3
2. Front Panel of the Microwave Power Controller
Control Chassis 4
3. Rear Panel of the Microwave Power Controller
Control Chassis 7
4. Block Diagram of the Microwave Power Controller 8
5. Chassis on the Environmental Control Package 12
6. Motor Mounted on the Varian Generator 13
A- 1. Inter-Chassis Wiring Diagram 16
A- 2. Cable PL 8 and PL 1 Wiring Diagram 17
A- 3. Control Chassis Wiring Diagram (Circuit Boards and
Rear Panel) 18
A- 4. Control Chassis Wiring Diagram (Front Panel) 19
A- 5. Board 1 Schematic 20
A- 6. Board 2 Schematic 21
A- 7. Board 3 Schematic 22
A- 8. Board 4 Schematic 23
IV
-------
A- 9. Chassis on Environmental Control Package (+28 V
DC Power Supply- and the Power Amplifier) Schematic ... 24
A-10. Chassis on Environmental Control Package
(Control Circuits) Schematic 25
A-ll. Parts Identification Board 1 [ 26
A-12. Parts Identification Board 2 ........ 27
A-13. Parts Identification Board 3 ...... 28
A-14. Parts Identification Board 4 . . . . . 29
TABLES
1. Microwave Power Controller Specifications 2
v
-------
ABSTRACT
This paper is a complete documentation of a microwave power
controller for use with a Varian Associates Model PPS-2.5 AS high
power industrial generator developed to improve the operating
characteristics of our 2450 MHz irradiation facility. The paper
includes theory of operation, photographs, circuit schematic draw-
ings, wiring diagrams and a parts list of the controller. The con-
troller makes the RF power output insensitive to low frequency line
voltage fluctuations and also permits the RF power output to be
programmed automatically.
VII
-------
ACKNOWLEDGMENTS
The author would like to express his appreciation for the
assistance of Mr. Daniel L. Dawes in the measurement of
the mechanical parameters of the Varian generator.
The efforts of the Information Services Section, Office of
Information, BRH in the preparation of the drawings and
photographs are appreciated.
Vlll
-------
INTRODUCTION
One of the functions of this laboratory is to examine the potential
hazards of microwave radiation by studying its effects on biological
specimens. The microwave radiation delivered to the specimen must be
closely controlled in order to acquire meaningful data and to assure
the reproducibility of the results. In our 2450 MHz irradiation
facility, microwaves are generated by a 3000 watt Varian Associates
Model PPS-2.5 AS high power microwave generator. The high voltage
power supply in this unit is unregulated and, therefore, the output
power fluctuates as the line voltage varies* During long-term exposures
(16 hours), the output power has varied as much as 20%.
A microwave power controller having the specifications given in
Table 1 was therefore developed to automatically negate the effects of
line voltage fluctuations. The controller also permits the exposure
time and the RF waveform to be programmed manually or automatically
through a data acquisition system provided that the waveform has a video
bandwidth no larger than approximately 2 Hz.
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TABLE 1
MICROWAVE POWER CONTROLLER SPECIFICATIONS
Operating Voltage 105-125 V AC
Line Regulation21 (± 10%) 0.11
Temperature Coefficient (20-30° C) 0.1%/°C.
Stability^ of Microwave Power ± 1.5% of set point with no
Output (48 hours) noticeable (to 0.2%) continual
accumulation of drift after
48 hours
Servo Bandwidth 2 Hz
Servo Deadbandc ± 150 W
Resolution of Readout (Digital
Panel Meter) 10 W
a"Line Regulation" is defined as the maximum percentage change
in the microwave power output caused by a ± 10% change in line
voltage either to the Microwave Power Controller, the Varian gener-
ator, or both.
Excluding transients of less than one second duration.
cFor errors greater than 150 W,the correction time is limited by
the 2-Hz servo bandwidth. For errors less than 150 W, the error will
be corrected by the integrator (OA 3). The maximum time before a
correction occurs is approximated by t = 30/A where t is the time
before a correction in seconds and A is the error in watts.
-------
DESCRIPTION
General
The Microwave Power Controller (MFC) is part of the 2450 MHz
irradiation facility which is depicted in Figure 1. The MPC can
be operated either in a manual or computer mode. In the computer
mode, the MPC accepts commands from the data acquisition system (DAS)
and in turn adjusts the output power of the Varian generator in a
closed loop fashion by means of a 0 10 V signal from a digital to
analog converter channel in the DAS. The microwave power is sensed
by an analog to digital converter channel in the DAS. There are also
several control and sense lines between the DAS and the MPC. These
allow the RF to be turned on and off, sense whether the RF is ready
to be turned on, interrupt the DAS processing if the MPC goes "out of
regulation," and sense whether the MPC is switched in the manual or
computer mode.
In the manual mode, the RF is activated and deactivated by push-
button switches, and the RF level is adjusted by a potentiometer.
COMMAND SIGNAL
MICROWAVE POWER SENSE
CONTROL & SENSE
DATA
ACQUISITION
SYSTEM (DAS)
LINES
MICROWAVE
POWER
CONTROLLER
MICROWAVE POWER
COMMAND
CONTROL & SENSE
LINES
VARIAN
MICROWAVE
GENERATOR
2450 MHZ
3.0 kW CW
MICROWAVE POWER
SENSE
I
ENVIRONMENTAL
PARAMETER
COMMANDS
ENVIRONMENTAj.
PARAMETER
SENSE
ENVIRONMENTAL
CONTROL
PACKAGE
AIR IN
AIR_OUT
ANECHOIC
CHAMBER
23 ft. long\
PHYSIOLOGICAL DATA
Figure 1. Block Diagram of the 2450 MHz Irradiation Facility.
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The MFC together with the Varian generator is a feedback control
system that maintains the microwave power output at a level determined
by a reference. The MFC generates a voltage that is dependent on the
difference between the reference level desired and the power actually
being generated. This error voltage is applied to a motor which is
coupled to a three-phase Powerstat^ variable autotransformer in the
Varian generator. The Powerstat controls the high voltage applied to
the magnetron tube and thus the microwave power. The microwave power
is sampled through a 25 dB crossgu'ide coupler and 30 dB of attenuation
with a crystal detector. The output of the crystal is signal con-
ditioned and compared with the reference. The power level is indicated
on the front panel by a digital panel meter.
Front Panel Controls and Indicators
The front panel of the MPC control chassis is shown in Figure 2.
> 0
-
L~—J
•
Figure 2. Front Panel of the Microwave
Power Controller Control Chassis.
LINE The line switch (push on - push off action) applies power to the
control chassis directly and also to the Varian generator and the Power
Amplifier Power Supply through a relay.
LINE INDICATOR The line indicator is illuminated when line voltage is
applied to the Varian generator.
WATER INDICATOR The water level indicator is illuminated only when
line voltage is applied to the Varian generator and sufficient water
is contained in the reservoir to cool the magnetron tube.
TEMP INDICATOR This indicator extinguishes if the temperature of the
magnetron exceeds a safe level.
Superior Electric Co.
-------
FIL ON The magnetron filament is energized by pressing the red fila-
ment switch (momentary action).
FIL OFF The magnetron filament is de-energized by pressing the black
filament switch (momentary action).
FIL INDICATOR The filament indicator is illuminated when power is
applied to the filament of the magnetron tube.
READY INDICATOR The ready indicator is illuminated after several con-
ditions have been met: The filament has had sufficient time to heat
(about two minutes); the two doors into the irradiation facility are
closed; the overload relay in the Varian generator has not been tripped;
and the timer enable/disable switch is in the disable position or the
switch is in the enable position and the timer has been set.
i
OVERLOAD The overload switch (momentary action) resets the overload
relay and returns the generator to the "ready" state if the conditions
under the paragraph Ready Indicator are met.
OVERLOAD INDICATOR The overload indicator is illuminated when the over-
load relay has been tripped. This relay is activated when there is
excessive plate current through the magnetron.
TIMER The timer is used to program an exposure duration into the MFC
when the controller is in the manual mode.
MANUAL/COMPUTER The manual /computer switch selects the mode of opera-
tion of the controller. In the manual mode, the reference is derived
internally and the duration of the exposure is controlled through push-
button switches or through the timer. In the computer mode, the power
level reference is supplied externally by the DAS. The RF power can
be switched on or off automatically in the computer mode; however, the
front panel push buttons will also operate in the computer mode.
ENABLE/DISABLE This switch is used when the MFC is in the manual mode
to place the timer in the circuit to permit exposures of preset dura-
tion. When the switch is in the disable position, the RF, once switched
on, must be switched off manually.
RF ON The RF on switch (momentary action) is used to turn on the
microwaves when the MFC is in the manual mode. The switch is operative
only when the ready indicator is illuminated.
RF OFF The RF off switch (momentary action) is used to turn off the
microwaves when the MFC is in the manual mode. The switch will function
when the MFC is in the computer mode if necessary.
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DEVIATION METER The deviation meter is used to indicate the error
between the actual forward power and the desired power level. Each
minor division represents 6 watts.
POWER The power control is a ten-turn potentiometer used to adjust
the microwave power over the range of 0 to 3.0 kW.
RF ON INDICATORS (TWO) These red indicator lamps are illuminated when
the RF is on. The RF on indicator nearest the power control is a flash-
ing indicator to provide a readily apparent indication that the generator
is fully energized.
OUT OF REGULATION INDICATOR This amber indicator is illuminated when
a failure in the MFC has occurred and the output has departed signifi-
cantly from the desired value.
OUTPUT POWER (DIGITAL PANEL METER) This meter indirectly indicates the
transmitted RF power level. A calibration curve has been determined
to convert the meter readings into watts of transmitted power (see sec-
tion on crystal detector below).
Rear Panel Connectors
The rear panel of the MFC control chassis is shown in Figure 3.
J^ BNC, Female. J., is the external reference input.
J BNC, Female. J2 is the 0 10 V analog signal proportioned to
forward microwave power.
J Amphenol Micro-Ribbon connector, Female. J, carries control and
sense lines from the DAS to the control chassis.
J. BNC, Female. J is the input from the crystal detector.
Jg BNC, Female. Jr is the output to the power amplifier.
J6 Amphenol Blue Ribbon Connector, Female. J? carries control and
sense lines from the control chassis to the chassis on the Environmental
Control Package.
-------
J2
J*- •> J5
o
/ ^
-
•
Figure 3. Rear Panel of the Microwave Power Controller
Control Chassis.
THEORY OF OPERATION
A block diagram of the MPC is shown in Figure 4. Functionally
the MPC can be thought of as a power leveller and as a remote control
terminal. The two functions interact in only a few cases.
Control Circuitry
As is evident from the preceding description of the front panel
controls and indicators, the Varian generator can be operated remotely
from the MPC front panel. The front panel wiring is shown in Appendix
A, Figure A-4. To achieve remote control operation, each normally open
switch in the Varian generator (see Appendix A Figure A-10) was paralled
by another normally open switch; a normally closed switch was added in
series to each normally closed switch, and indicator lights were added
in parallel to existing lights.
All of the generator remote switches are manually operated. How-
ever, the RF on and RF off functions can be controlled by the DAS when
the MPC is in the computer mode.
-------
oo
r
EXT. REF.
FROM DAS
FRICTION
COMPENSATION
OA5-6
GAIN
COMPENSATION
OA7
CHASSIS ON
ENVIRONMENTAL
CONTROL
PACKAGE
2SdB
CROSSGUIDE
COUPLER
COMPARATORS
OA9-10
TO DAS
I CONTROL CHASSIS iw UA:,
30dB
ATTENUATION
CRYSTAL
DETECTOR
MICRO-
WAVES
VARIAN GENERATOR I
Figure 4. Block Diagram of the Microwave Power Controller.
-------
In addition to these basic control circuits, the following control
circuits are used:
Priority Interrupt Relay K2 (see Appendix A Figure A-6) is energized
if the integrator output exceeds 10 V in magnitude. This relay is con-
nected to a priority interrupt line on the DAS. The integrator output
voltage does not exceed 10 V under normal operation because of the
integrator time constant.
Integrator and Reference Line Disable When the RF is off, the re-
ference line and integrator must be disabled. These functions are per-
formed by K4, Qi, and Ki (see Appendix A Figure A-6). These circuits
must be disabled when the RF is off to prevent the generation of an
unwanted error signal.
Power Leveller
Reference Generator The internal reference generator (see Appendix A
Figure A-6) consists of parts R5, C]_, DI} and R£. D^ is a 10-V zener
diode used as the reference. The voltage cross Dj is divided with a
ten-turn potentiometer, Rg. If the MFC is in the manual mode, the volt-
age at the wiper of Rg is then applied to OA 1.
Differential Amplifier (OA 1) OA 1 (see Appendix A Figure A-6) is
used as a unity gain differential amplifier which generates an error
voltage proportional to the difference between the reference voltage
(either internally generated or externally supplied) and the feedback
voltage derived from the crystal detector. This error voltage is dis-
played on the deviation meter (M 1) which is calibrated to 6 watts per
division.
Summing Amplifier (OA 2) The output of OA 1 is fed to the summing
amplifier (OA 2). QA 2 (see Appendix A Figure A-6) inverts the output
of OA 1 so that the integrator output and the proportional error volt-
age have the correct sign relationship. In addition, another input can
be applied to OA 2 through Rg. This input line is used only when the
RF is off, and it serves to keep the autotransformers in the Varian gener-
ator at the zero power position. Having the Powerstat wipers in the
zero power position prevents damage to them when the RF is switched on.
Integrator (OA 3) The integrator (see Appendix A Figure A-6) maintains
the average output power at the set value. An error that might not
otherwise be large enough to overcome the deadband of the system will,
with the integrator, be integrated through the deadband initiating a
correction. The integrator is also used to activate the "out of regula-
tion" indicator by energizing 1(3 when the integrator output exceeds 10 V.
A complementary driver (Q2, Q%) is needed to drive K2 and K^ since the
integrator output can be of either polarity.
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10
Swnming Amplifier (OA 4) OA 4 (see Appendix A Figure A-7) is used as
a unity gain summing amplifier to sum the integrated and proportional
error voltages.
Gain Compensation (OA 7) A nonlinear relationship was determined exper-
imentally between the Powerstat angular position and the microwave power
output. Output microwave power changed much more by a unit angular
rotation at high power levels than at low levels. The forward gain was
not constant and in fact increased as the output power increased. This
situation is highly undesirable in a servomechanism for it could cause
either a large deadband or an oscillatory system depending on the con-
stant value of forward gain selected.
OA 7 (see Appendix: A Figure A-7) is a gain compensation circuit which,
along with OA 9 and 10, correct for the nonlinearity in output power
vs. Powerstat shaft angle. R25 and R26 divide the output voltage of
OA 4 by ten. This is done to use OA 7 with a gain greater than one.
At low power levels both Q4 and Q$ are off and therefore the voltage
at the output of OA 4 equals the output of OA 7 (effective gain = 1).
At higher power levels, Q4 is switched on, thus reducing the effective
gain from OA 4 through OA 7 to one-half. The reduction in gain was
chosen to first compensate for the increase in gain between the Power-
stat shaft angle and output power. At still higher power levels, as
the generator gain increases still further, OA 5 is switched on to
compensate for this further increase.
A graph of power out vs. Powerstat shaft position indicated that only a
three line approximation to the curve was needed. The slope of each
line was translated into the compensating gain needed to make the over-
all forward gain constant, and the intersections of the linear approxima-
tions were translated into the output power at which the gain should be
changed. This last function is performed by OA 9 and OA 10.
Comparators (OA 9 and OA 10) The comparators (see Appendix A Figure A-7)
are used in conjunction with OA 7 to change the forward gain to compen-
sate for the change in sensitivity of power output vs. Powerstat shaft
angle. The comparator reference voltages are set for values determined
from the curve of power out vs. shaft angle, which has been approximated
by three straight lines. OA 9 and 10 sense the signal proportional to
microwave power and change the gain of OA 7 at the preset power levels.
The gain changes are effected at approximately 250 W and at 1.37 kW.
Friction Compensation (OA 53 OA 6) The Powerstat shaft on the Varian
generator has a large amount of friction due primarily to the pressure of
the wipers on the Powerstat coils. The friction was measured and found
to be 100 in.-oz. This friction would be detrimental to the operation
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11
of the servomechanism if left completely uncompensated because it would
introduce a large deadband into the system. If the deadband were to be
eliminated simply by increasing the forward gain, the system would be
oscillatory. Although the friction varies with Powerstat shaft angle,
a good deal of the deadband can be eliminated simply by applying an
extra 80 in.-oz to the Powerstat shaft.
This friction compensation signal is generated by OA 5 and 6 (see
Appendix A Figure A-8) and their associated components. Two stages are
necessary since the shaft can rotate in either direction. R,Q and R^g
determine how many watts error is to be allowed before the compensation
signal is generated. R,r and Rr? establish the level of the compensation
signal. The gain compensation stage is bypassed by the friction com-
pensation stages because the friction torque is approximately constant
with shaft position. The friction compensation circuits reduce the dead-
band by a factor of about five.
Summing Amplifier (OA 8) OA 8 (see Appendix A Figure A-8) acts as a
summing amplifier for the gain compensated error signal and the friction
compensation signal. The gain of this stage is adjustable through R56-
Power Amplifier (OA 14) Substantial current is required to drive the
Printed Circuit Motor1 (Motor 1). OA 14 (see Appendix A Figure A-9) in
conjunction with the power bridge (Qg-u)2 supply this high current
capability (see Figure 5). Only one power supply is needed for this
circuit providing economy in cost and space. Qg-n are mounted on
Wakefield Model NC-421A heat sinks since the power dissipation of each
transistor can be as high as 50 W.
Motor The motor used to drive the Varian generator Powerstat shaft is
a printed circuit DC motor. The motor is shown mounted on the Varian
generator in Figure 6. The motor was chosen for its low inertia
(0.099 oz.-in. sec.2) and high torque capability thus permitting a short
response time.
Crystal Detector The crystal detector is a Boonton Electronics Corp.
Model 41-4A. This detector was chosen because of its excellent tempera-
ture stability when operated with a load impedance of approximately 10
megohms. The temperature-induced drift in the detector output voltage
was approximately 0.05%/°Cover the temperature range of 15 to 28QC and
over the power range of -10 to +10 dBm with an output load impedance of
10 megohms when measured in our laboratory. However, this detector does
1Printed Motors, Inc.
2See Analog Devices, Inc., Model 408 Data Sheet
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12
Figure 5. Chassis on the Environmental Control Package
have the disadvantage that its output voltage is not linear with res-
pect to the input microwave power. A calibration curve has therefore
been determined to relate the digital panel meter readout to the
microwave power being transmitted from the 10 dB horn antenna.
FET Input Amplifier (OA 11) Since the detector described above should
operate with a high impedance load for optimum temperature stability,
a special operational amplifier is necessary to acquire the signal appear-
ing across this impedance. The bias current of bipolar operational
amplifiers would generate an excessive offset voltage if it were to pass
through R57 (Appendix A, Figure A-5), the high impedance load. Field
effect transistor (FET) input operational amplifiers, however, are well
suited for this purpose because their input bias current is orders of
magnitude lower than that of bipolar operational amplifiers. In addi-
tion since the minimum signal level of interest from the Booton detector
is 100 mV, the 25 yV/°C offset voltage drift specification of Analog
Devices Model AD516K is more than adequate.
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13
: _
Figure 6. Motor Mounted on the Varian Generator.
Active low Pass Filter (OA 12) OA 12 (see Appendix A Figure A-5) is
a low-pass filter with a bandwidth of about 70 Hz. The function of this
and the following circuit (OA 13) is to attenuate the detected modula-
tion frequencies of the RF output. Since the high voltage power supply
in the Varian generator is unfiltered and the filament supply voltage
is sinusoidal, there is about 101 RMS ripple with major components at
120, 360, and 720 Hz. The low-pass filter attenuates the 360 and 720
components to acceptable levels.
120 Hz Notch Filter (OA 13) Measurement of the spectral content of the
modulation indicated a 5% RMS 60 Hz component in the unmodified Varian
generator. The addition of a full-wave bridge in the filament circuit
of the magnetron tube doubled the frequency of this component to 120 Hz.
An active notch filter1 (see Appendix A Figure A-5) was used to eliminate
this component in the detected signal.
!See Motorola, Inc., Application Note N. AN-438.
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14
OPERATIONAL EXPERIENCE
The Microwave Power Controller has simplified the reproduction of
a desired field intensity at a given location by providing a digital
panel meter (DPM) readout of transmitted RF power. Previously a power
measurement had to be taken for each irradiation, subject to variations
due to dipole misalignment. With the MPC, an experimenter notes the
coordinates of his subject and the readout on the DPM. A field inten-
sity measurement is taken with a dipole antenna and a power meter where
the subject is to be located. If he wishes to rerun his experiment, he
simply places his subject in position after adjusting the DPM readout to
the value he noted from his initial run.
To aid in repositioning a subject accurately, members of our labora-
tory have designed a laser mount which allows experimenters to place a
small helium-neon laser in alignment with the throat and waveguide of the
transmitting horn antenna. This provides a simple and convenient means
of locating the axis of the horn antenna. Thus, for on-axis irradiations,
only the distance from the transmitting horn antenna must be measured to
define an exposure location.
The closed loop control has been particularly useful in cases where
a field in the anechoic chamber must be known over an area. Typically
an investigator must position the probe, take a reading, shut down the
RF power, reposition the probe, turn the power on and take a new reading,
etc. Using the MPC the investigator has only to push the "RF on" button
and the transmitted power is quickly reproduced without significant
drift.
Other features of the MPC which have proved useful are the "slow
turn on" circuitry, the door interlocks, and the remote control operation.
The "slow turn on" circuitry (R?> g^ g> 13 u 15 C2> D2) has greatly
reduced pitting of the autotransformers in the Varian generator. Pre-
viously, if the "RF on" button on the Varian console was depressed while
the autotransformers were not set for zero output voltage, the resulting
large current transient would pit the auto trans former windings. With
the MPC, R insure that the autotransformer is returned to the zero
/, o, y
output voltage position when the RF power is switched off. When the RF
is switched on, the remaining components insure that the turn-on will be
gradual with a time constant of about 2 seconds. The door interlocks
have been found essential for personnel safety. The interlocks are wired
so that if either the door to the anechoic chamber or the door to the
generator area is opened, the microwave power is immediately switched off
and will remain off whether or not these doors are then closed.
Lastly, having the MPC located in a control room has been found con-
venient. The control room houses the data acquisition system and the
environmental control console; therefore, the entire system operation
can be monitored from one location.
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15
APPENDIX A
WIRING DIAGRAMS, SCHEMATICS
AND
PARTS IDENTIFICATION
FOR
MICROWAVE POWER CONTROLLER
-------
CABLE PL 11-COAX
CABLE PL 10 - COAX
CABLE PL 2-TWO5COND.
DATA
ACQUISITION
SYSTEM
J4 p.
CONTROL
CHASSIS
CABLE PL 3-COAX
Ps CABLE PL 5-COAX P7
P6 CABLE PL1-30COND. P6
CABLE
PL 4
3-COND.
Pll
7 CHASSIS ON
ENVIRONMENTAL
<> CONTROL
PACKAGE
j<
no VAC
&GND
CABLE PL12-2COND.
CABLE PL 7-2 COND.
P, CABLE P18-30COND. P,
10
VARIAN
MICROWAVE
GENERATOR
10
CABLE
PL 6
3-COND.
110 VAC
&GND
A-l. Inter-Chassis Wiring Diagram.
CABLE
PL 9
4-COND.
220V-3*
&GND
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SPARES^
SPARES
P9
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
BLACK
RED
BLACK
WHITE
BLACK
GREEN
BLACK
BLUE
BLACK
YELLOW
BLACK
BROWN
BLACK
ORANGE
RED
WHITE
RED
GREEN
RED
BLUE
RED
YELLOW
RED
BROWN
RED
ORANGE
GREEN
WHITE
GREEN
BLUE
PL 8
P10
Varion Wire
and
Part Numbers
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
S
T
U
V
w
X
Y
z
a
b
c
d
e
f
g
h
i
k
1
m
> Series
with S-7
2
1
19
20
> Series with
S-2: K to S-3;
22J'°"
"X^Series with S-4:
37 \ M to S-4;
30>^ RtoS-5
26
*\ Series
S with S-8
SPARES
P6 PL
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
BLACK ^
RED
BLACK -^
WHITE -^
BLACK ^_
GREEN "^
BLACK ^
1
-<:
BLUE
BLACK -^ ^
YELLOW ^ ^
BLACK -..._, ^
BROWN ^ ^*
BLACK -^ _-
ORANGE ^
RED ^ ^
WHITE "^
RED -> ^
GREEN "^
RED ^
BLUE -^"
RED ^
YELLOW ^^
RED ^^
BROWN
RED -^
ORANGE
GREEN -^
WHITE ^
GREEN ^^
BLUE -^
-^c
P8
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
A-2. Cable PL 8 and PL 1 Wiring Diagram.
-------
00
BOARD 1
-------
U6 -
11J6 -«
13J6 -*•
UJ6 -*•
RESET
B BOARD 2 12J6 3J3
RF ON
OUT OF ^
REGULATION (^.
WATER H BOARD 2
15J6
16J6
560U TIMER ENABLE DISABLE
SW6
S BOARD 2
J1
SW8 RF OFF
O
19J6
20J6
F BOARD 2
DEVIATION
METER
C BOARD 1
OVERLOAD
5) 16
DPM
A-4. Control Chassis Wiring Diagram (Front Panel).
-------
N
R-*
FET INPUT
AMPLIFIER
ACTIVE LOW
PASS FILTER
ACTIVE 120 HZ
NOTCH FILTER
A-5. Board 1 Schematic
-------
DIFFERENTIAL AMP
SUMMING AMP
A-6. Board 7. Schematic,
INTEGRATOR
-------
GAIN COMPENSATION
COMPARATOR
COMPARATOR
A-7. Board 3 Schematic.
-------
-15
M -*
SUMMING AMP.
FRICTION COMPENSATION
A-8. Board 4 Schematic.
O-J
-------
Ti 8
K)
110V AC
2
_J_
4
5
6 O°
O
7 O*
28V DC POWER SUPPLY
-15V 27J8
"fOK
1
\
1
.112 r
R76L
.H2
-*-llOV@ 10 A
-*- TO MOTO R 1
POWER AMPLIFIER
A-9. Chassis on Environmental Control Package (+28 V DC Power Supply
and the Power Amplifier) Schematic.
-------
IP10 mPlO
u
nov AC
1T1
3T1
3J8 —-
4J8 -«-
»N»-
1
?
LINE
K9
12J8
20J8 -*
23J8
21J8 -*•
22J8 -*•
6J8 -*
6J9 -»•
K6
vOOQt^
MAN
AUTO
READY SENSE
16J9 16J8 25J8 26J8
TO FLASHING
WARNING LIGHT 112 19J8
12J9
J
1 ,
T (
i
RF|
i
K4
OFF
1
_^"
<
K8|
RFON
K5
RFON
SENSE
}
TO DOOR
INTERLOCKS
S9-10
2J8 1J8
4J9
-»- 2J9
5J8
8J8 i i 7J8
5J9
7J9
8J9
10J8
til
11J8
L
9J9
*- 10J9
'4J81 M3J8
11J9
13J9
14J9
A-10. Chassis on Environmental Control Package (Control Circuits) Schematic.
NO
in
-------
26
^^^^^
£ -sragi
*
Sgi+br.
'
ill
A-ll. Parts Identification - Board 1
-------
27
A-12. Parts Identification - Board 2.
-------
28
OA,
A-13. Parts Identification - Board 3.
-------
29
1 41
42
I
•
_ __
R,£
'* 45
-Q6
, >
ifiwrrr/ir
l3
A-14. Parts Identification - Board 4.
-------
31
APPENDIX B
ELECTRICAL PARTS LIST
FOR
MICROWAVE POWER CONTROLLER
-------
32
APPENDIX B--ELECTRICAL PARTS LIST
Sjymbol
Description
C7
C
8
'10
'11
'12
'13
'14
'15
'16
'17
D,,
D
D
3-4
'5-6
D7-8
D,
9-12
Capacitors
Diodes
D
13-14
.1 [iF, 50 V Disc
200 (iF, 25 V, Electrolytic
2 |iF, 50 V, Metallized Film
12 pF, 500 V, 10%, Dipped Mica
1 |iF, 200 V, Metallized Film
.05 (iF, 50 V, Disc
.5 [iF, .50 V, Mylar
.1 |iF, 50 V, Mylar
.0047 iiF, 200 V, Mylar
.47 M-F. 200 V, Mylar
.033 |iF, 200 V, Metallized Film
.15 tiF, 200 V, Mylar
.01 |j.F, 200 V, Metallized Film
.0022 [iF, 200 V, Metallized Film
.05 |iF, 50 V, Disc
21,000 |iF, 40 V, Electrolytic
.001 |iF, 200 V, Mylar
Zener, 1N4740A, 10 V, 1 W, 5%
Zener, 1N4728A, 3.3 V, 1 W, 5%
Silicon, 1N914
Zener, 1N4745A, 16 V, 1 W, 57»
Zener, 1N4738A, 9.2 V, 1 W, 5%
Molded Bridge Rectifier, MOTOROLA MDA 962-3
Silicon, 1N914
-------
Symbol
33
Description
Fuses
10 A 3AG SLO-BLO
1 A SAG Fast-BLO
Indicator Lamps
.-5
L7-8
L10
11
"12
Neon Lamp, Amber, Leecraft 32R-2113T
Incandescent Lamp, 6 V, 200 mA, White
Leecraft 32R-G1-2115T
Neon Lamp, Amber/ Leecraft 32R-2113T
Neon Lamp, Red, Leecraft 32R-2111T
Flashing Neon Indicator, Red, Dialco
928-1422-1631-638
Flashing Neon Indicator, Amber, Dialco
928-1422-1633-638
Incandescent Lamp, 25 W, 110 VAC
K
1-3
K
'4-6
K
7-8
K
Relays
SPST, Reed Relay, 6y, Fhipps Precision
Products, Model TA-6
SPOT, COIL 120 VAC, Potter and Brumfield
Model KNP-5A21-120 AC
SPOT, COIL 12 VDC, Potter and Brumfield
Model RS5D-12VDC
DPDT, COIL 120 VAC, Potter and Brumfield
Model MR 11A-120VAC
M
Meters
DC Microammeter, 50-0-50, General
Electric Model 185-112-CYCY
Digital Panel Meter, 0-1.999 Volts DC
Analogic Model AN2510-2B-1-RX-CX-A
-------
34
Symbol
Description
Motor 1
Motors
Printed Motors, Inc. Model U16M4, Printed
Circuit Motor
OA
1-10
OA
11
OA
12-13
OA
14
Operational Amplifiers
Frequency Compensated Operational Ampli-
fier, Fairchild UGE7741393
PET-Imput Operational Amplifier, Analog
Devices, Model AD516K
Same as OA
Power Operational Amplifier, Analog
Devices, Model 408
'1-2
4-5
8-11
R
1-4
5
R7
Transistors
2N3904 Silicon NPN
2N3906 Silicon PNP
MEM 511, Field Effect Transistor, P
Channel, Enhancement Mode
2N3906 Silicon MP
M3904 Silicon NPN
2N3055, 115 W, Silicon NPN
Resistors
(all resistors i W, 5%, Carbon Composition unless otherwise noted)
100 k ohms
1 k ohms
10 k ohms, 10 turn, w±rewound, Amphenol
2151 D
15 k ohms
620 ohms
-------
35
Symbol Description
Resistors (con't)
Rg 620 ohms
R 10 k ohms
R^3 15 k ohms
R , 12 k ohms
14
R-,. Ik ohms
Rig 820 ohms, ^ W, 5%, Carbon Composition
R, 7 100 k ohms, Cermet Trimmer, Beckman,
76 PR 100 k
R..g 100 ohms
R 10 k ohms, Cermet Trimmer, Beckman,
19 76 PR 10 k
ROQO-I 470 ohms, — W, 57,, Carbon Composition
R 10 k ohms
22-24
R9 _ 2.7k ohms
300 ohms
R 10 k ohms
27
1 k ohms, Cermet Trimmer, Beckman 76 PR IK
R 100 k ohms
29-30
R 5k ohms
31
&.,„ 5 k ohms, Cermet Trimmer, Beckman 76
PR 5K
-------
36
Symbol Description
Resistors (con't)
R33_34 100 k ohms
R_j. 10 k ohms
Roc 100 k ohms
->b
R37-38 Same as R,
R_Q 10 k ohms
R,Q Sames as
2 82 k ohms
R 47 k ohms
43
R,, 10 k ohms
R^5 Same as R3
R f 100 k ohms
46
R 10 k ohms
47
R.g Same as
R49-50 82 k °hms
R 47 k ohms
R ~ 10 k ohms
R53 Sames as R^
R 100 k ohms
54-55
R,-fi 500 k ohms, Cermet Trimmer, Beckman
76 PR 500 K
-------
Symbol
37
*5
R59
R
60
R
61
^63
^4-65
66-67
R
68
R
69
R
R
70
71
R72
R73
R74-83
R84-87
K.no
R
"89
Resistors (cont'd)
Description
6.8 Megohms
10 k ohms
Same as R
1.8 Megohms
1 Megohms, Cermet Trimmer, Beckman 89XRlMeg
2.2 Megohms
1 k ohms
47 k ohms
1 k ohms
Same as R
2.8k ohms
Same as R, q
27 k ohms
9.7 k ohms
300 ohms
.1 ohm, 5W, 1%, Dale RH-5 series
10 k ohms, 1/4 W, 1%, Metal Film
560 ohms
120 ohms
100 k ohms
-------
38
Symbol
Description
2-4
°6
S7-8
S9-10
Switches
SPOT, PUSH ON-PUSH OFF, ALCO MSP-105D
SPOT, Momentary, ALCO MSP-105F
4PDT, ON-NONE-ON, ALCO MST-405N
SPDT, ON-NONE-ON, ALCO MST-105D
Same as 82
Microswitch Limit Switch, Model 1LS1
Timer 1
Timer
Synchro-Motor Timer Liebel-Florsheira
Co., Cat. No. 4270600 Model 2 D
Transformer
Stancor Power Supply Transformer Model
RT-2012
* U.S. GOVERNMENT PRINTING OFFICE. 1972—484-487/314
-------
ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND MONITORING
TWINBROOK RESEARCH LABORATORY
The technical publications issued by the Twinbrook Research
Laboratory report results of intramural and contract pro-
jects. A limited number of the reports are distributed to
regional, state, and local radiological health agencies, to
universities and libraries, to other government and private
agencies, and to interested individuals.
The Twinbrook Research Laboratory technical reports listed
below are available from the National Technical Information
Service, Springfield, Virginia 22151. Microfiche copies are
$0.95 and paper copies are $3.00 unless otherwise noted. The
PB number should be cited when ordering publications from
NTIS.
PB 207 079 Krypton 85: A Review of the Literature and
an Analysis of Radiation Hazards (January 1972)
PB 208 233 Microwave Energy Absorption in Tissue
(February 1972)
PB Twinbrook Research Laboratory Annual Report
1971 (May 1972)
PB A Microwave Power Controller for a Radiation
Bio-Effects Exposure Facility (June 1972)
------- |