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25 January 1977 

Copy No. 


Quarterly Progress Report No. 2 under Contract N00140-76-C-6487 
1 September - 30 November 1976 

Dudley D. Baker et al. 

Contract N00140-76-C-6487 


JUN 1 11981 


Approved for public release• Htstribution unlimited 

81 6 11 094 



II. an/fqm-io(v) sonar test set field support 3 

A. Introduction 3 

B. Support for NAVSHIPYD PTSMH /-p ■; 3 



A. Introduction 5 

B. MX-9818/GQM-I Adapter, Filling Fixture, Transducer 5 

C. Transducer Positioning Systems 5 


A. Introduction 7 

B. AN/WQM- 5 , Ser A 3 , Sonar Test Set 7 

C. AN/WQM- 5 , Ser A 4 , Sonar Test Set 7 

D. AN/WQM- 5 , Ser All, Sonar Test Set 7 

E. AN/WQM- 5 , Ser A12, Sonar Test Set 8 

F. AN/WQM- 5 , Ser A 13 , Sonar Test Set 8 

G. AN/VJQM-5, Ser A 17 , Sonar Test Set 9 

H. AN/VQM- 5 , Ser Bl, Sonar Test Set 9 

I. AN/tfQM-3, Ser B 5 , Sonar Test Set 9 



A. Introduction 13 

B. Operational Testing of the AN/VfQM -7 Test Set 13 

C. AN/SQM-( ) Engineering Model lk 



A. Introduction 17 

B. Liaison uith Seismic Engineering Company 18 

C. Visits to the TRFs at NAVSHIPYDs PEARL and MARE l8 


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A. Introduction 21 

B. Revision of tne Sonar Dome Hai-doook, Volume V , 21 

Submarine Sonar "Domes , NAVSEA 096?-LP-412-30^0 

C. Revision of the Sonar Dome Handbook, Volume II , 22 

AN/SQS-26 Steel and Rubber Sonar Domes , 

NAVSEA 0967-LP-412-3020 

D. Revision of the Sonar Dome Handbook, Volume IV , 22 

AN/SQQ-23 Rubber Sonar Domes , 

NAVSEA 0967 -LP-412-30l+0 


A. Procurement of AN/fyQM-5 Series Field Change Kits 23 

B. Procurement of an AN/VQM-5A Sonar Test Set for 23 



A. Introduction 25 

B. Basic ARL Design 25 

C. Present Status 26 

D. Design Review by Instruments, Inc. 30 

E. Demonstration at NAVSEA 51 





Applied Research Laboratories (ARL), The University of Texas at 
Austin, was awarded Contract N00140-76-C-6487, sponsored by the 
Naval Underwater Systems Center, New London Laboratory (NUSC/NL), 
effective 1 June 1976. Some of the work under this contract repre¬ 
sents a follow-on effort to previous work sponsored by NUSC/NL 
under Contract N00140-74-C-6316. 

The work under Contract 1100140-76-C-6487 is divided into six 
task areas that focus on technical support in areas of sonar 

I. AN/PQM-10(V) Sonar Test Set Field Support 

II. Transducer Repair Facility Test Site Field Support 

III. AN/WQM-5 Sonar Test Set Field Support 

IV. Special Purpose Passive Sonar Systems Support 

V. Sonar Instrumentation Test and Evaluation 

VI. Study of Towed Line Array Acoustical Testing at Transducer 
Repair Facilities 

This report is Quarterly Progress Report No. 2 under Contract 
N00140-76-C-6487. Chapter headings in this report correspond to the 
six task areas. Additional chapters are included on documentation 
support, procurement of AN/WQM-5 components and field change kits, and 
AN/BQR-5 power supply development. 



A. Introduction 

ARL provides material and technical support for six AN/FQM-10(V) 
sonar test sets located at three Naval shipyards with Transducer Repair 
Facilities (TRFs): Portsmouth Naval Shipyard (NAVSHIPYD PTSMH) at 
Portsmouth, New Hampshire; Mare Island Naval Shipyard (NAVSHIPYD MARE) 
at Vallejo, California; and Pearl Harbor Naval Shipyard (NAVSHIPYD PEARL) 
at Pearl Harbor, Hawaii. In addition ARL maintains a pilot AN/FQM-10(v) 
at its Lake 'Travis Test Station (LTTS). 

This work is a continuation of previous efforts at ARL under 
Contract N00126-72-C-17^8 and Contract N001 1 40-7 i +-C-63l6, Task 0001AA. 
Quarterly progress reports issued under those contracts are applicable 
references for tie present work. 

During this report period, ARL has provided support for the test 
sets as described in the following paragraphs. 


Upon request ARL furnished the AN/FQM-10(v) Ser 5 at NAVSHIPYD 
PTSMH with the following: 

(1) two input signal relays for the CML power amplifier, unit No. 6^, 

(2) two operational amplifiers (Analog Devices 202) for the calibrator, 
unit No. 15, 

( 3 ) two relays (10k MPOX-lk) for the pulse vector immittance meter 
sampler, unit No. $0, and 

(4) two ARL constructed mounting brackets for the two Digitec digital 

RrtECLuL.J laOi FIL .iii 


ARL received, repaired, calibrated, and returned the Tektronix 
model No. RM 56 U oscilloscope from the AN/FQM-10(v) Ser 5 at NAVSHIPYD 


A. Introduction 

ARL provides material and technical support for the TRF test sites 

This work is partially a continuation of previous efforts at ARL 
under Contract NOOl4o-74-c-63l6, Task 0001AA, and the quarterly progress 
reports issued under that contract are applicable references for the work 
now continuing under Contract N00l40-76-C-6^87. 

B. MX- 9818 /GQM-I Adapter, Filling Fixture, Transducer 

Three of the five valves on each filling fixture are to be replaced 
by more dependable bellows valves and this replacement will in turn 
necessitate a change in the connecting copper tubing. The fixtures will 
be modified to reflect the change as soon as ARL receives the valves. 

C. Transducer Positioning Systems 

Most of the work is in the detailed design and drawing stage. All 
of the design and assembly drawings have been completed and are now in 
the machine shop; a few parts have been completed. Some purchased items 
have been received, but the long lead items have not yet arrived. 


IV. AN/WQM-5 sonar test set field support 

A. Introduction 

Naval Sea Systems Command (NAVSEA) assigned ARL the responsibility 
of being the designated overhaul point (DOP) for repairing AN/WQM-5 
components. In addition to being the DOP, ARL also provides field 
maintenance engineering support for the 27 AN/WQM-5 Sonar Test Sets 
located at various Naval shipyards and laboratories. 

During this report period, ARL has provided support for several of 
the test sets, as described in the following subsections. 

B. AN/WQM-5, Ser A3, Sonar Test Se t 

Upon request ARL sent to NAVSHIPYD PTSMH one of each of the following 
printed circuit (P.C.) boards: No. 1A10, No. 1A12, No. 1A30, No. 1A31, 
and No. 1A32. All boards were returned unused except P.C. board No. 1A31, 
which had several failed components. 

C. AN/WQM-3, Ser A4, Sonar Test Set 

ARL sent one P.C. board No. 1A11 and one P.C. board No. 1A30 to 
NUSC's Dodge Pond test facilities, as requested by Mr. R. Handfield of 
NUSC/NL. Also, ARL sent to NUSC/Dodge Pond one 2 kHz to 4 kHz plug-in 
filter for the readout monitor in exchange for one 4 kHz to 8 kHz filter. 

D. AN/WQM-3, Ser All, Sonar Test Set 

STC Ruebling of COMPACAREA COGARD requested one P.C. board No. 3A3 
to replace his malfunctioning board. Also, he requested the loan of 


ARL’s signal generator while the Ser All signal generator was being 
repaired at ARL. The P.C. board and the Ser A8 signal generator were 
shipped to STC Ruebling in San Francisco. 

E. AN/WQM-3, Ser A12, Sonar Test Set 

Upon request ARL sent one P.C. board No. 8 a 6 to Mr. D. West of 
Naval Ship Engineering Center at Norfolk (NAVSECNORDIV). Later, 
during the same month, the power supply and power amplifier units 
received extensive electronic and mechanical damage. Both units were 
sent to ARL for repairs while NAVSECNORDIV used ARL's Ser A8 power 
supply and amplifier. The units were repaired, calibrated, and shipped 
back to Mr. West. The units were again being used with the Ser A12 test 
set when the power supply absorbed an irregular variation in the ac 
line voltage and, once again, the two units were damaged. The Ser All 
power supply and amplifier are at ARL being repaired at the time of 
this report - 

F. AN/WQM-5, Ser Alj, Sonar Test Set 

Mobile Technical Unit No. 6 (MOTU 6), custodian of the AN/WQM-5 
Ser A13 test set, requested technical assistance. Mr. G. Warren of ARL 
visited USS PUGET SOUND (AD 38 ), a destroyer tender, where the Ser A1J 
test set was located. 

It was discovered that P.C. board No. lA Jl in the readout monitor, 
unit No. 1, had failed. A replacement was made and the unit was returned 
to operation. A complete test set inspection revealed a bad capacitor 
in units No. 9 and No. 10, two bad switching transistor P.C. board 
assemblies (No. 8A1 and No. 8 a 4) and a missing cable (W-13B). These 
items were furnished by ARL. 

Later, when the test set was used to evaluate a transducer aboard 
USS BARNEY (DDG 6), it proved to be operating properly. 


G. AN/UQM-3, Ser A17, Sonar Test Set 

As requested, ARL furnished NAVSHIPYD MARE with a sample delay 
potentiometer (No. 1R1) for their readout monitor. 

H. AN/WQM-5, Ser Bl, Sonar Test Set 

MOTU 4 in Groton, Connecticut, sent a Tektronix model No. 434 
oscilloscope to ARL to he repaired and is temporarily using ARL's 
Ser 8 oscilloscope. 

MOTU 4 also contacted Mr. G. Warren of ARL about a malfunction 
in their data recorder--the printout column No, 17 did not always 
print. Mr. Warren suggested pulling P.C. boards No. 3A5 and No. 3A6, 
cleaning the contacts on the edge connectors, and switching the 
positions of the two boards, which are identical. The cause of the 
problem could be determined by a process of elimination. If the 
problem was a bad component on P.C. board No. 3A5, column No. 12 would 
not always print. If the problem was a bad connection between the 
P.C. board and its connector, the problem would not recur. The problem 
proved to be the latter and was corrected. The data recorder was 
returned to operation. 

I. AN/WQM-3, Ser B9, Sonar Test Set 

Mr. D. J. Tucker, custodian of the AN/WQN-b, Ser B3, requested two 
P.C. boards (No. 1A9) for the readout monitor, four integrated circuits, 
and three transistors for the Tektronix model No. 434 oscilloscope. The 
items were sent by ARL via air express to meet Mr. Tucker's limited time 
f rame. 



This task was not funded, in the original contract but was 
funded late in July 1976. ARL did not work on this task during this 
report period. It is expected that work will begin early in 
December 1976. 

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A. Introduction 

ARL participated in two projects under this task. The first 
project was the first article testing, at the Lake Travis Test Station 
(LTTS), of the AN/VQM-7 Sonar Test Set, previously called the Sonar 
Test and Evaluation Equipment (STEE). This project was completed and 
is described in section VI.B. 

The second project, described in section VI.C., is the design of a 
replacement for the outdated AN/SQM-5 Sonar Noise Recorder. 

B. Operational Testing of the AN/WQM-7 Test Set 

ARL conducted tests on the AN/WQM-7 Sonar Test Set during 
17 June - l 6 July 1976. These performance tests were conducted with 
the AN/BQR-2, AN/BQA- 8 B, and AN/WLR-12 sonar systems aboard ARL's 
STEP Barge located at LTTS. The results of the performance tests were 
described in QPR No. 1 under this contract. 

A classified report describing the AN/VQM-7 testing (ARL Technical 
Letter TL-EA- 76 -ll of 27 August 1976, revised l 6 September 1976), 
forwarded to NAVSEA during the last report period, was revised to include 
a plot showing the dynamic range problem. The revised report and several 
additional plots were forwarded to NAVSEA by ARL Itr Ser E -198 of 
17 September 1976 . 

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C. AN/SQM-( ) Engineering Model 

ARL began work on the design of a breadboard model of the 
AN/SviM-5 replacement in September 1976. The configuration that was 
chosen consisted of an HP 9825A programmable calculator, a Tektronix 
4662 x-y plotter, a 2-speed synchro-to-digital/digital-to-synchro 
converter unit and an interface/true rms detector unit. The last 
two units will eventually be combined in a single unit. 

The HP 9S25A calculator was chosen as the system controller for the 
following reasons. 

(1) The calculator has the speed necessary to read the data, 
compute the necessary parameters, and output the results in real time 

(2) The additional memory available in the basic calculator 
allows long records of data to be stored during a noise plot. The 
data can be stored on a magnetic tape after the run is completed. 

(3) The calculator has a built-in alphanumeric display for 
displaying program-selected parameters, such as bearing and true rms 
noise amplitude. 

(4) The size and weight (25 lb) of the calculator allow it to be 
easily transported. 

Because of these characteristics, the slightly higher cost of this 
calculator, as compared to the cost of the HP 98I6A (described in 
QPR No. 1 under this contract), is more than offset by the reduction 
in other necessary hardware. 

The Tektronix 4662 plotter was selected because of its light weight 
(30 lb), speed, and built-in functions, such as character generation. 

The unit’s I/O structure is compatible with the IEEE 488 bus standard, 
which allows it to be plugged directly into the calculator. 

The design and construction of .the interface/true rms converter 
was completed by ARL on 24 November 1976. The synchro-to-digital/ 
digital-to-synchro unit was designed and built by C-Tech, Inc., Massena, 



New York. ARL personnel visited C-Tech, Inc., during the week of 
18 October 1976 for the purpose of specifying the solid state 
synchro unit. By 19 November 1976, the synchro converter, composed 
of standard electronic modules, had been built and tested by 
C-Tech, Inc. The completed unit was received by ARL on 23 November 

By 30 November 1976, all units of the AN/SCiM-3 replacement had 
been interfaced, and development of the software necessary to 
acquire the data and make the required noise plots was nearly complete. 
Performance tests on the completed breadboard model are expected to 
take place at NAVSECNORDIV in early December 1976. 



A. Introduction 

ARL originally worked under Contract N00024-75-C-6C70 to 
technically assist NAVSEA with the project to expand the capabilities 
of the Navy's three TRFs to encompass several new kinds of trans¬ 
ducers, most of which are towed line hydrophone arrays. NAVSEA's 
plan is to equip the TRFs by FY 79 for repairing and testing the 
towed line arrays used with the following sonar systems: AN/BQQ-5, 
AN/BQQ-6, AN/SQR-18 (IEIAS), AN/SQR-19 (ETAS), and AN/BQR-25 (STASS). 

In addition to these towed arrays, the plan includes equipping the 
TRFs to repair the transducers associated with the AN/WQM-5/6 Standard 
Acoustic Target Source (SATS) and the AN/WQM-7 equipment. 

ARL's work began in 1975 as an extremely modest effort primarily 
to maintain liaison with the sponsors in NAVSEA headquarters who are 
responsible for the equipment and to gather technical information about 
the various transducers. This early work led to the assignment of two 
small tasks to ARL to continue this effort. In June 197&, a task was 
begun under Contract N00l40-74-C-63l6 to continue the study phase of 
the effort begun under Contract N00024-75-C-8C70. A task under 
Contract N00140-76-C-6487 >*as funded at ARL in August 1978. However, 
the funding was received so late in the month that the effort actually 
began on 1 September 1978. The effort has been limited to a visit 
to the facility of one of the towed array manufacturers and visits to 
the TRFs at NAVSHIPYD MARE and NAVSHIPYD PEARL. In December, visits 
to another manufacturer and to NAVSHIPYD PTSMH will be made under 
Contract NQ0140-74-C-6316. In this way, the two modest efforts are 
mutually reinforcing as ARL continues to gain more information about 

FfltCbul«J i*lah bi-AWE-NOi FlU'iU 


the project. The following paragraphs describe more details of the 
effort under the subject contract. 

B. Liaison with Seismic Engineering Company 

On P.2 September 1976, Messrs. G. E. English, P. S. Adair, 

E. Blum, and R. E. Brothers of ARL visited Hydroscience, Inc., and 
Seismic Engineering Company, Inc., both subsidiaries of Whitehall 
Corporation. Mr. J. Hayes, Systems Engineer of Hydroscience, Inc., 
was ARL's guide and only source of information during the visits. 
Hydroscience, Inc., under subcontract to Edo Corporation, is 
providing the towed line array used with the AN/BQR-I8 system. 

Seismic Engineering Company, the sister company to Hydroscience, Inc., 
is actually the manufacturer of this array. Information was obtained 
about the function of the system, the kind and number of hydrophone 
elements, special features, and specifications and methods used for 
fabrication and testing. A detailed report of this trip is 
presented in Appendix A of this report. 


The TRF at NAVSHIPYD PEARL was visited during 4-5 November 1976 
by Messrs. G. E. English, E. Blum, and R. E. Brothers of ARL and 
E. M. Spurlock of Stanford Research Institute (SRI). The towed line 
array repair/test (TLAR/T) work was discussed with Messrs. R. Shigeta, 
Combat Systems Electronics; P. Pollock, NAVSHIPYD PEARL Shop 67 
Superintendent, and A. Perry, Assistant TRF Supervisor. Since the 
purpose of the visit was to establish liaison, details were not 
discussed. Items of interest and action from this meeting are detailed 
in Appendix B. 

The TRF at NAVSHIPYD MARE was visited during the period 
8-12 November 1976 by Messrs E. Blum of ARL and E. M. Spurlock of SRI. 
During 8-9 November, Messrs. P. D'Entremont a:cd D. Schuler, TRF 


foremen, discussed the general form and layout of the TLAR/T work and 
pointed out to Messrs. Blum and Spurlock the two areas being 
considered for the TLAR/l facilities. During the period 
10-12 November, a meeting was held to critique the TB-16/BQ 
Restoration and Repair Manual and to discuss the relationship of 
the TB-16/BQ and other TLAR/T work. A list of those attending the 
10-12 November meeting and items of interest and action from the 
8-12 November meetings are in Appendix B. 



ARL participated in three tasks in the area of documentation 
support, which focused on producing the Sonar Dome Handbook. 

B. Revision of the "Sonar Dome Handbook, Volume V, Submarine Sonar 
Domes, 11 NAVSEA 0967-LP-412-3050 

During August a dozen draft copies of the Handbook were submitted 
to NAVSEA and NAVSEC for review. While this review was underway during 
September, ARL continued to refine the text. On 29 September, further 
changes and revisions required by the various groups within NAVSEA 
and NAVSEC were provided at a meeting at NAVSEC headquarters. These 
changes and revisions were compiled early in October and redrafting 
of the text and tables began. New illustrations for the AN/\i/IjR- 9 
section as well as clarification about access to the AN/BQR-7 galleries 
on SSNs were obtained from NUSC/NL. By 50 November, the Handbook had 
been about 85% rewritten. Because of the in-depth review given to 
this material in September, each chapter, as it is being rewritten, 
is being made camera-ready. All chapters will have been submitted to 
NAVSEC for approval by the end of December. If the Handbook is 
satisfactory, it will be necessary to add only a table of contents, 
a list of illustrations, a list of tables, a glossary, and an index 
before it is printed. The appropriate preliminary work on these items 
has been done. Artwork for the covers is ready, except that this 
artwork must show the date on which input of technical data to the 
Handbook was completed. When this date is confirmed, covers can be 
ordered; delivery is expected within 4 to 6 weeks. 


Steel and Rubber Sonar Domes, NAVSEA C&oJ-LP-kl2-$020 

During this report period, the manuscript for Volume II of the 
Sonar Dome Handbook has undergone revision. The IBM Mag Card II 
machine was used to facilitate this revision. Editing and typing of 
this document have been completed, and the plastic covers have been 
received; however, additional work is required on several of the 
figures. It is expected that the manuscript will be ready for 
proofing by NAVSECNORDIV during the next report period. 


The manuscript for Volume IV of the Sonar Dome Handbook is complete. 
Two copies of the new manuscript were sent to NAVSECNORDIV on 12 November 
1976 for review. As soon as the manuscript is approved, ARL plans to 
reproduce 200 copies. 

Revision of the "Sonar Dome Handbook, Volume IV, AN/SQi^-2^ 
Rubber Sonar Domes, ,f NAVSEA 0967-LP-412-30^-0 





IX. AN/VQM-5 procurement and field change program 

A. Procurement of AN/WQM-5 Series Field. Change Kite 

Because of many delays in obtaining purchase approval and the 
lengthy procurement cycle at The University of Texas at Austin, a 
purchase order for AN/^QM-5 Field Change Kit components was not 
issued until 2 November 1 $76. The purchase order was awarded to 
C-Tech, Inc., of Massena, New York. The field change components 
procured under Contract N00140-76-C-6487 are supplemental to those 
being procured simultaneously under Contract N00l4-0-7^C-63l6. The 
total field change program is as follows. 

10 AN/VQM-5A Field Change Kits 

5 AN/WQM-5B Field Change Kits 

5 AN/VQM-5C Field Change Kits 

In the same procurement, one AN/WQM-5A Field Change Kit for Spain 
is being purchased (see section B). 

An integral part of the hardware for the field change kits is a 
quantity of programmable calculators and plotters that ARL will 
obtain directly from Hewlett-Packard and will integrate with the 
items obtained from C-Tech, Inc. An OEM agreement has been negotiated 
and was signed on 2 December 1976. Thus, it is expected that the 
equipment from Hewlett-Packard will be ordered in December 1976. 

B. Procurement of an AN/WQM-3A Sonar Test Set for Spain 

All components of the AN/VQM-5A for the Spanish Navy are on 
order. QFR No. 1 reported that the original AN/VQM-5 components 
were ordered in June 1976. The new AN/VQM-5A components were 

included in purchase orders discussed in section A. Only the lot 
of spare parts is not on order at present. It is expected that these 
items Mill be identified and ordered in December 



A. Introduction 

AEL was tasked under Contract N0002k-74-C-1069 by NAVSEA 
Code 660F to perform a study of the current switching power supply 
(built by IBM) which is used in the AN/BQQ-5 sonar system. This 
basic study has progressed to a new design proposed by ARL that 
should make the reliability requirement of 100,000 h MFBF a reality. 

The work under Contract N00140-76-C-6487, a follow-on to the 
original study, requires ARL to fabricate and demonstrate a model 
of the proposed new supply. 

B. Basic ARL Design 

ARL has designed a switching power supply for the AN/BQQ-5 sonar 
system to meet the required 100,000 h MTBF. This improvement is made 
possible by the use of fewer parts, a different circuit design which 
includes redundancy, and use of state-of-the-art electronic components. 

The "flyback" technique in switching design has properties 
that make it much more reliable than the "bridge" or "half-bridge" 
designs; that is, the input is completely isolated from the output. 

This feature allows paralleling of power stages (redundancy) without 
interaction. Also, the paralleled stages can be energized out of 
phase, reducing the ripple current required for the input and output 
filter capacitors. 

The power switching module shown in Fig. 1 is the basic building 
block for the supply. Figure 2 shows the switching power supply module 
waveforms. The power transistor (MJ 10005) will be operated within the 



MAG- 55083- A2 
♦120-200 V 0621 

L p = 2 wiH, 880 ^.H 









published safe operating area (SOA). The switching speed is fast for 
high efficiency and the input drive requirements are well controlled 
and do not strain the "housekeeping" supply, which is an independent 
power source of relatively low power used to drive the output stage 
and perform other sense and feedback, functions. 

The driver (NH0026) in the switching module is a monolithic 
circuit capable of driving ±l.f A in a switching mode. Thus, there 
is little dissipation in the chip (approximately 0.2y w) and only 
one external part is required. Isolation is achieved by driving 
the base of the output transistor with a small transformer and 
having secondary windings on the power storage element ("flyback" 

In the "flyback" operation, some stored energy is lost due to 

leakage inductance of the power transformer and the turn-on time of 

the output diodes. The result of this loss shows up as a high voltage 

spike on the collector of the power transistor. If this spike is not 

snubbed at a voltage below V of the transistor, second breakdown 


will occur and the transistor will cease operating. 

Each of the output diodes on the switching module isolates 
itself from other modules that are in parallel with it. If no energy 
is transferred to the secondary because of some failure in the module, 
then the output diodes remain back-biased. 

Since the switching modules are under the greatest stress in the 
power supply, redundancy will increase the reliability. There are 
several tradeoffs involved but the best compromise is having any two 
switching modules out of four be able to handle the full load. This 
means that, if all four modules are operating at full output, the 
supply could produce twice the power required. Under all operating 
conditions, each module handles its share of the load. 


Input and output filter capacitors must operate near their 
maximum rated rms ripple current. Redundant switching modules reduce 
the current. By phasing the drive to each module, the contribution to 
the rms ripple current is lowered. With two modules operating, the 
current is lowered by 30$; with three modules operating, the current is 
lowered over 50 %; and with four modules operating, the current is reduced 
by 65 %. Both input filter capacitors and output capacitors must be 
paralleled to handle the ripple current, which is undesirable 
since it reduces reliability. The best solution at this time is to use 
more capacitors (each fused) than are needed so that, in case of either 
a short or an "open,” the number of operating capacitors is reduced by 
one and the failure does not shut down operation. 

The housekeeping supply is a nonswitching, totally redundant 
design. Two linear, single phase 6 VA transformers, each on a 
different phase of the input 3-phase line, have separate rectifiers 
and two output capacitors. Fusing is chosen so that a failure of any 
component either opens or blows a fuse, and the supply continues to 

The voltage reference, sensing, shutdown, startup, and associated 
circuitry should be reliable, but sections that are not redundant should 
be kept to a minimum number of parts; also, redundant sections must be 
isolated from each other or the redundancy does not improve the 

Use of a chip (SG 152k) reduces the number of discrete components 
enough to allow the use of redundant chips (SG 1524) to further increase 
the reliability. 

C. Present Status 

ARL has executed the new switching design to conform to the 
physical requirements by using plug-in printed circuit cards. Each 


card has an integral heatsink which greatly increases the shock 
resistance and heat dissipation of the supply. 

One of the critical heat dissipation problems is related to the 
ripple current carrying capability of both input capacitors and the 
output capacitor. This capability is directly related to temperature. 
Because capacitors are also difficult to shock mount, methods of 
mounting were studied so that the heatsink would not be bulky and 
would be easy to manufacture. 

The basic power supply (with two driver modules) has been built 
to the configuration of the type 4-B supply. The circuitry to perform 
the necessary housekeeping functions has also been constructed but 
the start-up overload, and normal operation circuitry are still on 
the drawing board. 

The concurrent work on the reliability study is progressing at 
a rapid rate. The MIL 217-B program of the ARL design is approaching 
the final stages; it should be possible to start varying parameters 
in the next quarter and to have a full-blown printout covering all 
aspects of the design by the end of March. Preliminary data on the 
driver module indicate an MTBF of 600,000 h, including the redundancy 
of two out of four modules. 

D. Design Review by Instruments, Inc . 

Messrs. E. English and B. Shaw visited Instruments, Inc., on 
21 October 1976. The basic structure and circuits of the new design 
were explained to Mr. M. Fry, who previously evaluated the IBM design. 
ARL has retained Instruments, Inc., as a consultant on this work, and 
the design review was completed by the end of the report period. The 
report resulting from the design review is included in Appendix C. 


E. Demonstration at NAVSEA 

A basic working supply in a dummy package was demonstrated to 
Messrs. D. Baird, J. Archer, and B. Daney at NAVSEA Headquarters. 

The demonstration was to show that the new design could fit within 
the physical envelope of the type 4--B supply. Several advantages of 
the new supply were immeuately obvious: (l) all cards can be plugged 
in, making the supply field-repairable, (2) bids could be sent to 
vendors on a card basis, which would encourage competition, (3) there 
will be no "soft" wires in the supply, and (4) the reliability should 
be much higher than that of the present supply. 

It was determined that a complete working model should be built 
at ARL and tested at IBM late in March 1977- The mechanical and 
temperature requirements would be eased (no shock or full temperature 
excursions) for the March 1977 tests. 




22 September 1976 

FHk.Ck.uinJ tjJih bUU*X»NOr FIL 1 &L 1 




DATE: 27 September 1976 

FROM: Richard E. Brothers 

TO: Electroacoustics Group File 

SUBJECT: Trip to Hydroscience, Inc., Dallas, Texas, 22 September 1976 

Accompanied by Messrs. G. Earle English, Robert S. Adair, and 
Eugene Blum, I traveled to Hydroscience, Inc., Dallas, Texas, on 
Wednesday, 22 September 1976, for consultation with Mr. Jerry Hayes, 
System Engineer for the AN/SQR-l 8 Towed Array. 

Drawings and specifications for the AN/SQR-18 Towed Array are 
not available to our people at this time. Mr. Hayes stated that he 
expected to receive a contract in November 1976 that would allow him 
to release drawings and specifications to AKL/UT. Mr. Hayes' telephone 
number at Hydroscience, Inc., is (21k) 6 30-0911. The AN/SQR-18 is a 
"can you give it to us now" type project, according to Mr. Hayes, and 
drawings are not in a releasable form. The following information was 
released to us verbally by Mr. Hayes. 

The AN/SQR-l 8 Towed Array consists of three modules, one sensing 
module, and two vibration isolation modules (VIMs). The array has a 
total length of 670 ft, is 2.7 in. in diameter, weighs 1700 lb, and is 
stored on a 300 lb reel. The AN/SQR-18 is neutrally buoyant; this is 
accomplished by filling with N0RPAR-12, an isoparaffin produced by 
Exxon. The array is manufactured by Seismic Engineering Company of 
Dallas, Texas. Specifications are not available from Hydroscience or 
Seismic but could possibly be obtained from Edo Corporation in 
New York, New York. 

The sensing module is 225 ft long and 2.7 in. in diameter and 
weighs 600 lb. The AN/SQR-18 sensing module uses Multidyne MD-2 
hydrophones. The MD-2 has four elements; we were not informed how they 
are internally connected. Externally, two wiring studs are available; 


i-Ri,CEwi»«G buAhK-NOi' FlU-ib 

27 September 1976 


Page 2 

a twisted pair is connected to these. Edo Corporation has the 
confidential specifications of the MD-2. The hydrophone is supposedly 
nonrepairable and Seismic will not sell hydrophone components. The 
physical load of the sensing module is carried by three 5/32 in. in 
diameter galvanized improved plow steel cables. These cables are held in 
position by spacer floats, made out of Lexan or polypropylene. The 
spacing of these floats is not available; the spacers are fastened 
to the cable by soldering. 

There are two VTMs; each has a length of 220 ft and a diameter 
of 2.7 in. and weighs 550 lb. The shock absorber used in the VIM is 
nylon rope (three strands are used), which will stretch 2 to 2 1/2 
times its length. The rope is specified by Edo Corporation. The 
rope is held in position by the same spacers used in the sensing 
module, and the spacers are held in place by crimps on either side. 

The wire bundle in the VIM is 150$ in length and is looped and held 
in place by rubber bands when it is being put into the shell. These 
rubber bands dissolve when the shell is oii filled. 

Both the sensing module and the vibration interface modules are 
encased in a polyurethane shell, which is the casing that holds the 
oil fill. A vacuum is pulled on this shell so the modules can be 
slipped in easily. The skinning pipe used to apply this vacuum is 
A in. in diameter and is heated for winter use. 

We left for Austin at 1535 h and arrived here at lolG h. 


Richard E. Brothers 

Copy to 

Robert S. Adair 
Eugene Blum 
G. Earle English 
Bill S. Shaw 




DATE: 30 September 1976 


PROM: E. Blum, G. E. English, R. S. Adair, and R. E. Brothers 
TO: Electroacoustics Group File 

SUBJECT: 22 September 1976 Travel to Hydroscience, Inc„, and Seismic 
Engineering Company, Subsidiaries of Whitehall Corp. 

Arriving at Hydroscience, Inc., near the beginning of the -working day, 
we contacted Jerry Hayes, a systems engineer and "sole survivor" at 
Hydroscience on the AN/SQR-18 project, who was our guide and answer man 
for the tour. Jerry came on with a basically disinterested attitude; 
he offered no information but answered direct questions pretty well, 
except those that he thought would appear in the Cat E drawings which 
he expects to get money to prepare. He was also reluctant to answer 
questions which he felt were answered by the Edo contract specification. 

He said that Edo Corporation anticipates sending them money for these 
drawings near the beginning of December 1976. His Edo, New York, 
contacts are Jonathan Shere and John Vinsinzo, (212) 445-6000. 

Jerry Hayes' Hydroscience, Inc., number is (214) 63 O-O 9 H. 

The first part of the morning was spent in the conference room at 
Hydroscience with the sample towed array section and PR-type movie and 
the second part of the morning was spent at the Seismic Engineering 
manufacturing plant. The first part of the session in the conference 
room was 3pent using the sample towed array section as a basis of 
discussion. Then he showed the movie. The movie was reshewn and used 
as a basis of discussion and was stopped whenever anybody had a question. 
The following is a disjointed list of items we picked up in the 
conference room. 

30 September 1976 


Page 2 

1. Jerry feels that basically we will need a copy of the list of basic 
manufacturing facilities in order to restore and repair the AN/SQR-18. 

2. The filling fluid is an Exxon isoparaffin called NORPAR-12 with 
the specific gravity of O .65 or so (depending on requirements for 
neutral bouyancy). 

5. The cable is 5/32 in. galvanized improved plow steel (3 ea.) 
using standard aircraft swaging techniques, eyes, etc. 

4. There is no oil processing; nothing is cleaned before it is 
assembled. Dirt can be seen "roaming around" inside the oil in the 
sample towed array section. 

5. The elements are Seismic MD-2. All of them are hardwired with a 
twisted pair. 

6 . The wire is No. 26 or 30 in the sensing module. (Jerry didn't respond 
to the question about the insulation.) 

7. Apparently, the way the array is put together, oil can "hose" up 
the wire, and oil can even hose up the 2 -cable wire. 

8 . The tow cable is off the Vector shelf. Seismic terminates the wet 
end and Edo terminates the dry end. 

9 . The M/SQH-18 gets no tension testing; they merely test the swaging 
tool performance every so often. 

10. It takes 30 sec to solder each place where the steel cable is 
attached to a spacer. 

11. It costs $ 7 /ft for the strength members, spacers, and skin. 

12. The tow cable armour is contrahelically wound. 

13. The elements are essentially nonrepairable. Seismic would probably 
sell the whole MD-2 but not any of the parts. 

14. The spacers in the Id are Lexan but Seismic also uses polypropylene 
or syntactic foam. 

15. Solder volume in the spacers and other things like the specific 
gravity of the filling fluid are used to adjust the neutral buoyancy 
of the towed array. 

16. There is no test, as such, for saltwater infiltration. 

30 September 1976 
Page 3 

17. Repair of spacers would have to be determined and done on an 
individual basis since spacers are hard to get out and replace. 

18. Seismic's calibration work is done at Leesburg. Based on the results 
of the calibration, a slight change of sensitivity occurs with pressure. 

19. The nylon rope (capable of 250$ stretch) in the VIM is designed 

on an individual-as-needed basis (towing speed, etc.) and is held in place 
with National Telephone crimp fittings cn both sides of each spacer. 

The wire is put in the VIM at 150$ length (tied initially with 
rubber bands which dissolve or untie in the oil after booting and 

oil filling.) The plastic sheet stretches with the nylon at least as 
far as the design calls for. The nylon rope appears to be "Goldline" 

(high quality) climbing rope. 

20. The booting on the 18 is polyurethane. Small repairs can be 
accomplished by merely cutting off a small section of boot, making 

the repair, and replacing the cut-out section with a stretched overboot. 

21. For major repairs, the skin is disposable. 

22. Noncorrosive flux is used in all government work; otherwise 
acid flux is used on the solder. 

23. The main failure mode of the modules is physical damage. 

24. The "thing" is always oil filled in the vertical mode by snaking 
the array over a series of "nails" in the wall described later in 
this report. Vacuum is apparently not necessary since all bubbles can 
be seen and can be shaken out by hand. 

We then drove to Seismic Engineering Company and viewed the towed array 
manufacturing area (but missed the calibration room which Jerry 
described verbally in 25 words or less on the way back to Hydroscience). 
The manufacturing area at Seismic was a very simple affair. Major 
points noted are as follows. 

1. Urethane varnished work benches made of chip core divided area 
into two work spaces about b in. wide; the back lip is about 2 in. 
high and the front lip is about l/2 in. high; two of the benches are 
back to back with a 5 in. inner tray. 


30 September 1976 


Page 4 

2. Other work benches are maybe a total of 22 in, wide divided down 

the middle. If the work bench isn't full length, enough width is necessary 
to allow the array to double back on itself several times. Also, plywood 
tables are used. The cable bundle is held in air under tension for 
wirewrapping over 10 to 12 ft span. 

3. The cable is hand tensioned even when it is lying on-bench for most work. 

4. Tables do not have electric outlets along them except where they 
are using soldering irons on the aircraft cable. 

5. Unraveling lacing technique used. Tied very hard near the 
breakout points for the hydrophones. 

6 . The "4 in. skinning pipe" (booting fixture) stretches way out 

into Seismic's back lot and is capable of skinning about 100 m. The end 
is stuffed over a mandrel which has an inside diameter large enough 
to accept the array. The boot is pulled through by a rope or string 
and then a big piece of waterhose is used to connect the outside of the 
mandrel/boot connection to the outside of the pipe with hose clamps. 

A pig is blown through and the array is pulled in from a snake 
arrangement on the floor after the vacuum is pulled. 

7. White deposit (zinc oxide) on the galvanized cable sent back 
for repair appears to be considered normal here. I think it could be 
due to moisture and air carried by the filling fluid (isoparaffins 
are fairly hygroscopic) or maybe to saltwater infiltration. 

8 . They haven't tried coiling the skinning tubes to conserve floor 
space and don't particularly care to, 

9. Jerry thinks that somebody like Western Electric uses a pressure 
outfit rather than a vacuum skinning device and they put the oil in 
and everything in that one move. 

10. The skinning pipe appears to be 4 in. standard pipe. They use heaters 
in the winter for stretching the boot because when it gets cold it 
doesn't stretch very well. Heating is accomplished with heating tape 
under insulation all down the skinning tube in about 12 ft sections. 

11. The elements are single-end mounted using the sheet metal screws 
in the holes provided in the spacers. 


30 September 1976 


Page 5 

12. Various parts are stored rather haphazardly under the workbenches: 
boxes of swages, boxes of plastic hydrophone inserts, coils of the 
nylon rope, the separators, etc. 

13. The wire is on racks that have wheels for stripping to make a new 

14. Somebody actually sits around and cuts the rubber bands into lengths 
so that they can be tied and used. Hot blow gun is used for heat shrink 
on the connectors. 

15- The need for the jigs and fixtures for the aircraft cable 
connectors hopefully will not exist at the TRFs but the fixtures are 
definitely necessary if cable and replacement is necessary. 

16. Wiring diagram comes with each cable. 

17. The length of hangers on the wall for vertical filling of the 
array is about 40 ft long and the protected hangers are about 6 or 
8 in. long and about 4 ft apart and about 6 ft high. 

18. 24 in. is the absolute minimum storing diameter for the VIM. The 
bigger the better. Normal handling, say a 4 ft diam. On the workbench 
it is not as critical, apparently, for short term operation. 

19. They find a spool of heavy twine very handy especially near the 
end of the workbenches. 

It was generally agreed that many of Seismic's methods are not 
economical for manpower or floorspace. There's got to be a better 

G. Earle English 



Robert S. Adair 


Eugene Blum 

Richard E. Brothers 




(1) Items of Interest and Action from 

4-5 November 1976 Meeting 

8-12 November 1976 Meeting 

(2) Attendance List for 
10-12 November Meeting at 





Items of Interest and Action from 
4-5 November 1976 Meeting 

ARL received 

six NAVFAC drawings 

of Bldg. 

214 as 


Drawing No. 


Il 60 709 

Civil: Site Plan 





Floor Plan 





Floor Plan 


Arc hitectural: 



Floor Plan 





Floor Plan 





Floor Plan 

These drawings are sheets 1-6 of 64. Drawing 709 has a complete 
drawing list so that we can obtain more information as necessary. 

These plans will enable ARL to lay out floor plans for the proposed 
TLAR/T site. Also, small sketches of the first, second, and third 
floors were obtained with markings indicating the present TRF on the 
first floor and the proposed addition on the second floor. 

2. During the tour of Bldg. 214, P. Pollock (NAVSHIPYD PEARL Shop 
Superintendent) indicated that the floor space actually available was 
somewhat more flexible than indicated on the sketches. An addition to 
Shop 67 is due to be built in FY 79- The actual ramifications of 
this addition are not yet clear. 

5. ARL verbally presented a broad outline of ARL's task and extent 
of the TLAR/T function. Except for the need for a straight run with 
225 ft booting fixture, ARL was unable to give NAVSHIPYD PEARL TRF 
any detailed information about the quantity or type of floor space 
required. It was generally agreed that ARL would keep the TRF informed 
as plans become more definite. 

Enclosure (l) to 
EAG Trip Report 

« 4 q Ser TR-EA-1 

i-HECtwLw buAhiUhOi' FlU±v 

4. Mr. Pollack indicated that, with the possible exception of the 
megohmmeter and very common hand tools, the TRF would like to see ail 
new, dedicated equipment for TIAR/T. When given a choice between 
having the electronic test equipment separate or mostly confined to 
a rolling panel rack, they chose the panel rack without any hesitation. 

5• Of note is the fact that NAVSHIPYD PEARL TRF is by far the smallest 
and most ill-equippeu TRF of the three. It handles perhaps 12',I of the 
total work volume. Transducers are stored outside, in the sun. The 
test tank is only 30 ft high and does not have an adequate walkway. 

If in-water testing is to be done in the tank, a walkway, perhaps 
similar to the ones at NAVSHIPYD MARE and NAVSHIPYD FTSMH, will have to 
be built. Structural drawings of Bldg. 214 will have to be obtained, if 
this is true. A larger instrumentation house would also be appropriate. 

6 . Since the weather at NAVSHIPYD PEARL is very clement year around, 
some of the equipment could be installed outside. This equipment could 
be protected by a large open leanto which could also be used to help 
cover the shipping/receiving/storage area. 



Items of Interest and Action from 
8-12 November 1976 Meeting 

1. ARL received two copies of three NAVSHIPYD MARE drawings of 
machinery arrangement for Bldg. 866, sheets 1 (first floor), 3 
(second floor), and 4 (third floor) of 6. On one of the copies, 
the first floor drawing is delineated by an area that may be set 
aside for TLAR/T. ARL was also given a taped-together Xerox copy 
of a large air-conditioned section of Bldg. 627 being considered 

for TLAR/T, which is located about 2 miles north of Bldg. 866. This 
particular area is more like a 400 ft by 200 ft cave. 

2. ARL verbally presented a broad outline of ARL s task and the 
extent of the TLAR/T function. Except for the need for a straight 
run with 225 ft booting fixture, ARL was unable to give NAVSHIPYD 
MARE TRF any detailed information about the quantity or type of floor 
space required. It was generally agreed that ARL would keep the TRF 
informed as plans become more definite. 

3. Schuler requested an overall "people tree" starting with Herman and 
going through vendors, NAVSEA responsibility, ARL, shipyards, SRI, 
NUSC/NL, and everyone else involved with this effort. ARL indicated 
this tree might be ready in time for the January TRF meeting. 

4. The only reasonable place in the area alloted in Bldg. 866 for 
the booting fixture is attached to column row E (on the column row D 
side) approximately 13 ft off the ground with work platforms at both 
ends. The SW end of the fixture cannot extend past column E8 because 

it would interfere with the rail tracks. It must be 13 ft high to avoid 
interfering with the path to the elevator between Ell and E12. 

Enclosure (3) to 
EAG Trip Report 
Ser TR-EA-1 


5. It was suggested that reel stands for handling all arrays be 

of a common variety and perhaps of the same variety as the installing 
activity. When given a choice between having the electronic test 
equipment separate or mostly confined to a rolling panel rack, Mr. Schuler 
chose to have the equipment separate. 

The following items were brought out at the TB-l6 Restoration 
and Repair Manual meeting. 

6 . The restoration and repair manual is not adequate as written. 

Major points brought out included the need for a working specification 
for most of the electronic instruments in addition to a recommended 
up-to-date vendor mode. 1 , number and better descriptions of the 
specialized work areas, jigs, and fixtures. 

7. Three TS-3575 /BQ's were already being purchased and sent to the 
TRFs. ARL should talk to NAVSEA 06HU-3 (V. Graves) about routing one 
or more of these through ARL. 

8 . Cliff Porterfield had done an 11 page "nitpick" critique of 
approximately $/h of the R&R manual. ARL is to respond to the R&R 
manual in 30 days if ARL has any further comments. 

9 . ARL is now on the mailing list for R&R manuals, ILS plan revisions, 
maintenance plans, support equipment list, and interim repair parts 
lists, etc., concerning the TB-l6. 

10. Common items between the intermediate maintenance areas and the 
TRFs include the test set (TS-3575), a portable fill and pressure rig 
for oil, roller racks, and jack stands. 

11 . Bob Mahnke, NUSC/NL, is the man to see about the TS-3‘i7S> manual. 


12. Drawings for the TB-l 6 will be forthcoming. A sample section 
of the TB-16 may be available in 6 mo. 

13. McGonegle says to talk to Dave Cain, the in-house NUSC/NL man 
at CID. ARL will call McGonegle next week and have him set up the 
tour with Dave Cain. 

14. There is now a "stabilized" man-day rate per man-day with a cost 
included at NAVSHIPYD MARE. 

15. The 3-element cluster in the TB -16 is a throwaway and 
uneconomical to repair. 

1 6 . NAYSEA has moved to National Center Bldg. 2 and all the telephone 
numbers have changed. 

17. The exact testing to be done at the TRFs is to be determined at 
ARL with advice and comments from everyone else concerned. 

1 8 . Porterfield specifically requested an inspection table which 
would allow the array to be rolled circumferentially as well as axially. 


10-12 November Meeting at NAVSHIPYD MARE 




S. Shimomura (BQQ-5 ILS) 

Hydrotronics, Inc. 

(705) 790-527 

Ron See 

Hydrotronics (Anaheim) 

(714) 776-5051 

J. R. McGonegle (BQQ-5) 

NAVSEA 660F-52 

( 202 ) 692-0968 

E. M. Spurlock 

SRI - STEP Liaison with 

(415) 526-6200 

R. C. Long 

NAVSEA 04512 

( 202 ) 456-1695 

Eugene Blum 


(512) 656-1551 

Frank Peglow 


(707) 646-2554 

A1 Carey 


(707) 646-2575 

Cliff Porterfield 


(707) 646-2575 

Herman Evans 


AV 222-7894 

Enclosure ( 5 ) to 
EAG Trip Report 







I * 

* J 



DAVID C. KAltFtU. Ph.D.-Pfudnl 

(714) 223-7156 

October 28, 1976 

For Applied Research Laboratories - University of Texas 

Michael N. Fry 

INTRODUCTION Earl English and Bill Shaw visited Instruments, Inc. on October 21, 

1976. They brought schematics for a 400 W switching power supply and a 
prototype switching module. 

Mr. Shaw explained his design philosophy and reported on measurements 
taken on breadboarded modules in Austin. We conferred on current limit 
and start-up circuitry. 

We have been asked to review the circuitry as thus far developed. 

OVERVIEW The approach has impressed us very favorably. New components have 

made a reduction in total parts count and an increased redundancy possible. 

Novel techniques allow the redundant switching modules to operate in 
quadrature to reduce both switching currents and output ripple voltage. 

Our main criticisms are that adequate short and start-up circuitry 
has not been developed, and that the interconnection of the redundant 
modules may eliminate the redundancy, (i.e. A failure in one module 
may effect one or more of the other three) 


This is basically the same as the existing BQQ-5 supply. The capacitors 
are individually fused so that a single failure will not shut down the 
supply. Selection of the proper capacitor is most critical. TVo pos¬ 
sibilities are the Sprague type 604D and the Tansitor type AT. 

The fuses should have a 200 volt rating to allow proper clearing. 

This supplies 10 - 16 V, at about 4W. The unregulated 120-200 volt 
output of the input rectifier is used as a reference to allow proper 
timing for the switching module. 

We understand that a small 60 Hz isolation transformer is being con¬ 
sidered for this application. This could be very beneficial, reducing 
parts count (20% of total) and improving efficiency. The main drawback 


FRfcCfculwti bUUiK~MOr FlLei JuU 

Review of AN/BQQ-5 Power Supply 
October 28, 1976 

Page 2 

to such a transformer is quality control associated with the thousands of 
turns of very small wire which is required. This approach should be 
seriously explored, but only if vendors can demonstrate very high reliability. 

The switching regualtor being considered in Fig. 2 should have a 
current limit resistor in the emitter of the MJ10001 and should be tied 
to pins 4 6 5 of the SG1524 to aid in start-up. 

We feel that suitable line voltage information can be obtained from 
the reverse voltage on the housekeeping transformer winding. This would 
allow fixed voltage regulation and remove some of the uncertainties in 
the switching module base drive at the line voltage extremes. 

The inputs and outputs should be fused, not only to maintain redundancy, 
but to guard against an insulation failure in the transformers. 


The single-ended inverter requires higherpeak voltage and current in 
the transistor than the half-bridge approach, but a single Darlington 
transistor has twice the rating necessary in this application. Also the 
ease of paralleling modules and the simplified drive circuitry makes 
this a very attractive choice. 

The normal operation of this inverter is to turn on the switching 
transistor until the transformer core material is nearly saturated, then 
turn off the transformer until the magnetic energy is completely transfered 
to the load (output). 

If the output is low, (i.e. initial start-up or shorted load), the 
magnetic energy will transfer very slowly. '" the transistor is turned 
on before transfer is complete, the transistor may be forced into linear 
operation and be destroyed. 

Protection against this condition may be obtained by sensing emitter 
current and turning the transistor off before overload occurs, or by sensing 
transformer discharge and inhibiting turn-on until the secondary voltage 
has reversed and passes through zero. Emitter current sense is suitable 
only when the logic circuitry is common with the emitter (not is this case). 
The voltage sense could probably be incorporated with a few parts and the 
shutdown input of the SG1524 regulator chip. +iov 

Review of AN/BQQ-5 Power Supply 
October 28, 1976 

Page 3 

The 150V, 10W zener diode on the primary of T2 is necessary to 
absorb the energy in the leakage inductance. If the primary and the 
secondary are tightly coupled, the zener can be reduced in rating or 
eliminated. T2 should be wound so that each primary turn is in close 
proximity to one or more secondary turns. Each secondary winding should 
have a low inductance path to a fast rectifier and low inductance capacitor. 

Isolated base drive is always difficult to implement, and this circuit 
makes the usual compromises. T1 couples forward base drive from the N40026 
clock driver, but reverse base drive is sacrificed to keep parts count low. 

The NH0025 does maintain a low impedance state during the "off” 
period, but extraction of stored charge in the switching transistor is 

Fortunately, the fall time of the Darlington transistor is somewhat 
invariant with reverse drive, and the single ended inverter can tolerate 
fairly long saturated delay times. 

Unfortunately, the fall time determines the dissipation in the transistor, 
and Motorola specifies fall time with a high current, -5V turn off drive. 
Therefor each device used should be tested under actual operating conditions 
for acceptable fall times. 

Reverse base drive can be accomplished by passing forward base drive 
through a capacitor and using the stored charge for reverse bias. In this 
regulator, short "on" times during start-up and low output would result in 
insufficient stored charge, and almost no reverse drive. 

The NH0025 is a highly sophisticated clock driver meant for driving 
capacitive loads at fast slew rates. Its complexity is not warranted in 
this application, but it does the job in a small space. 

It is inefficient, consuming up to 40 mA internally to drive 120 mA 
into Tl. Its dissipation could be reduced by reversing its logic. As 
shown in Fig. 3, the "off" state is the high dissipation state. 

to SGI524 


Review of AN/BQQ-5 Power Supply 
October 28, 1976 

Page 4 

The unused half of the NH0026 could be used to generate reverse 
drive, or disabled by grounding its input. 

If the housekeeping supply was regulated at ■•■16V, and line voltage 
information developed by other means, the SG1524 outputs could drive the 

This circuit will provide 200 mA of forward base drive and up to 
2.5V @ 100 mA of reverse drive if the forward drive has been on for at 
least 5 microseconds. The dissipation in the SG1524 is increased, and 
its output current limiting is being used although it is not a specified 
parameter and would require testing each device. This circuit has a re¬ 
duced part count than the NH0026 circuit and might prove more reliable. 


This module contains the pulse width modulation circuitry necessary 
to regulate the output. It uses four Silicon General SG1524 integrated 
circuits to allow independent control of the four switching modules. 

As shown in Fig. 4, the SG1524's are connected so some individual failures 
can interfere with operation of the other three. 

The SG1524's share the 10 - 16 V supply, and an internal short will 
stop everything. If the driver circuitry is fused, each SG1524 could be 
powered from that fuse. 

The internal oscillators are synchronized with diodes and 10 kilohm 
resistors. Loss of power to one SG1524 could stop the oscillator in the 
device ahead of it. Replacing the diodes with emitter followers would 
eliminate that interference. 


Review of AN/BQQ-5 Power Supply 
October 28, 1976 

Page S 


As shown, the SGl524's are tied together at pin 1 in order to share 
the output current among the switching modules. As with the oscillator 
sections, loss of power to one would load the others. Also, the output 
current of a single error amp (internal to the SG1524) appears insufficient 
to drive the other three. A single external op-amp appears necessary to 
drive the SG1524's, probably through 10 kilohm buffering resistors. The 
inputs (pins 1 5 2) to the unused error amps should be tied to the internal 
5 volts (pin 16) to avoid interfering with the SG1524's bias system. 

A soft start system could be tied to the main loop output rather than 
the housekeeping supply. That will limit the conduction angle until the 
output has increased. This has the effect of foldback limiting and may 
not allow the output to start up into non-linear loads. The voltage 
sense circuit discussed earlier (Fig. 5) will allow full current into 
all loads. 

The proposed supply appears to be very well suited to the components 
now available. The high voltage Darlington transistors and the integrated 
circuit switching regulator appear to make a very compact and simple power 
supply possible. 

25 January 1977 

1 September - 30 November 1976 

Copy No. 

1 - 3 









Receiving Officer 

Naval Underwater Systems Center 

New London Laboratory 

Building 43 

New London, CT 06320 

Attn: Code NA401 

Office of Naval Research 
Resident Representative 
Room 582, Federal Building 
Austin, TX 787 OI 

Electroacoustics Group, ARL/UT 

Engineering Services Division, ARL/OT 

Eugene Blum, ARL/UT 

James R. Bryant, ARL/UT 

James J. Truchard, ARL/UT 

Gary G. Warren, ARL/OT 

Library, ARL/UT 

FHkCbi/li i Mih bUUkK—NOi FlLt>JUJ