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DEC-11-HBKEF-A-D

September 1974

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Document:	BA11-K Mounting Box Manual
Order Number:	DEC-11-HBKEF-A-D
Revision:	0
Pages:	84
Original Filename:

OCR Text

BA11-K mounting box
manual

DEC-II-HBKEF -A-D

BA11-K mounting box
manual

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.""

digital equipment corporation · maynard. massachusetts

1st Edition, September 1974

Copyright © 1974 by Digital Equipment Corporation
The material in this manual is for informational
purposes and is subject to change without notice.

(

Digital Equipment Corporation assumes no responsibility for any errors ~hich may appear in this
manual.

Printed in U.S.A.

The following are trademarks of Digital Equipment
Corporation, Maynard, Massachusetts:
DEC
FLIP CHIP
DIGITAL
UNIBUS

PDP
FOCAL
COMPUTER LAB

f.,

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CONTENTS
Page

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r
~

CHAPTER 1

BA11-K CHARACTERISTICS AND SPECIFICATIONS

1.1
1.2
1.2.1
1.2.2
1.3
1.3.1
1.3.2

GENERAL
PHYSICAL CHARACTERISTICS
BA 11-K Characteristics . . . . . .
H765 Power System
... .
ELECTRICAL SPECIFICATIONS ' ..
BA11-KE, BA11-KF Input Power Electrical Specifications
BA l1-K Output Power Specifications
........ .

CHAPTER 2

SYSTEM UNITS, OPTIONS AND HARNESSES

2.1
2.1.1
2.1.2
2.1.3
2.2
2.3
2.4

SYSTEM UNITS
Introduction
......... .
System Unit Configuration
...
System Unit Installation
OPTIONS . . . . . . . . . . . .
POWER DISTRIBUTION WIRE COLOR CODING
CAB LE ROUTI NG . . . . . . . . . . . . . . . .

CHAPTER 3

H765 POWER SYSTEM

3.1
3.2
3.2.1
3.2.2
3.2.3
3.2.4
3.2.5
3.3
3.4
3.4.1
3.4.2
3.4.3
3.4.4
3.4.5
3.4.6
3.4.7

INTRODUCTION
MECHANICAL DESCRIPTION
H744, H745, and H754 Regulators
7010014 Transformer Assembly
7009811-1, -2 AC Input Box .. ,
1211714 Box Fan
....... .
5410864 Power Distribution Board
SYSTEM FUNCTIONAL DESCR IPTION
SYSTEM CIRCUIT DESCRIPTION
AC Input Box . . . . .
Transformer Assembly
5409730-YA Regulator
H744 +5 V Regulator .
H745 -15 V Regulator
H754 +20, - 5 V Regulator
Power Distribution Board .

...............

............

iii

1-1
1-1
1-1
1-5
1-6
1-6
1-8

2-1
2-1
2-1
2-3
· 2-10
· 2-10
· 2-10

3-1
3-1
3-1
3-2
3-2
3-2
3-2
3-2
3-5
3-5
3-5
3-8
3-10
· 3-14
· 3-15
· 3-16

CONTENTS (Cont)
Page
CHAPTER 4

MAINTENANCE

4.1
4.2
4.2.1
4.2.2
4.3
4.3.1
4.3.2
4.3.3
4.3.4
4.3.4.1
4.3.4.2
4.3.4.3
4.3.4.4
4.3.4.5
4.4
4.4.1
4.4.2
4.4.3
4.4.4
4.4.5
4.4.6
4.4.7

MAINTENANCE EQUIPMENT REQUI RED
PREVENTIVE MAINTENANCE
General . . . . . . . . . .
Physical Checks . . . . . .
MAINTENANCE PROCEDURE
H765 Power System Fault Isolation
Voltage Regulator Checks and Adjustments
Voltage Regulator Troubleshooting . . . .
Regulator Bench Test Procedures (H744, H745 and H754)
Initial Tests . . . . . . . .
Output Short Circuit Tests . . . . . . . .
...... .
Testing a "Dead" Regulator
Testing a Voltage Regulator After Repairs
5409730-Y A Regulator Test Procedure . .
H765 POWER SYSTEM SUBASSEMBLY REMOVAL PROCEDURE
Introduction
.............. .
H765 Power System Access Procedure . . . . . . .
H744, H745, and H754 Regulator Removal
AC Input Box and 5409730-YA Regulator Removal
Fan Removal . . . . . . . . . . .
Transformer Assembly Removal
Power Distribution Board Removal

CHAPTER 5

UNPACKING AND INSTALLATION

5.1
5.2
5.3
5.4
5.4.1
5.4.2
5.5
5.6

INTRODUCTION
UNPACKING . . . . . . . . . . . .
INSTALLATION IN A CABINET
AC POWER SUPPLY CONNECTION
Connecting to 115 Vac or 230 Vac
Quality of AC Power Source
REMOTE POWER CONTROL . . .
INSTALLATION CERTIFICATION

4-1
4-1
4-1
4-1
4-2
4-2
4-4
4-6
4-7
4-7
4-8
4-8
4-9
· 4-11
· 4-11
· 4-11
· 4-12
· 4-12
· 4-15
· 4-15
· 4-17
· 4-17

5-1
5-1
5-1
5-1
5-1
5-3
5-4
5-4

ILLUSTRATIONS
Figure No.

1-1
1-2
2-1
2-2
3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
4-1
4-2
4-3
4-4
4-5
4-6
4-7
4-8
4-9
4-10
5-1
5-2
5-3

Page

Title
BA l1-K Mounting Box (Top Covers Removed)
BA l1-K Physical Layout
System Unit Configurations
Unibus Connection
Power System Functional Block Diagram
Power System Detailed Diagram
115 V Power Configuration
230 V Power Configuration
Power Control Simplified Diagram
5409730-Y A Power Up and Power Down
Voltage Regulator El, Simplified Diagram
H744 Regulator Waveforms
Power Distribution Board ...
H744 Connection Diagram
H765 Fault Isolation Flowchart
Regulator Adjustments
Typical Voltage Regulator Output Waveforms
H765 Power System Access
Regulator Removal
AC Input Box ....
Fan Removal
Transformer Assembly
Transformer Assembly Removal
Power Distribution Board Removal
BA l1-K Packaging
Connector Specifications
Power Control
.....
•

••

•

1-3
1-4
2-2
2-11
3-3
3-4
3-6
3-6
3-7
3-9
3-11
3-13
3-17
3-18
4-3
4-5
4-10
4-13
4-14
4-16
4-18
4-19
4-20
4-22
5-2
5-3
5-5

TABLES
Table No.

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,,~--- -

1-1
1-2
1-3
1-4
1-5
2-1
2-2
2-3
4-1
4-2
4-3

Title
BA 11-K Physical and Environmental Characteristics
H765 Power System Physical Characteristics
BA11-KE Input Power Electrical Specifications
BA 11-KF Input Power Electrical Specifications
BA l1-K Output Power Characteristics
SU Installation Requirements .....
PDP-11 Family Models and Options
Power Distribution Wire Color Coding
Maintenance Equipment Required
Regulator Specifications .......
H744, H745, H754 Voltage Regulator Troubleshooting Chart
v

Page
1-1
1-5
1-6
1-7
1-9
2-3
2-4
2-10
4-2
4-6
4-6

INTRODUCTION

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This manual describes the general specifications, installation, theory of operation, and maintenance
procedures that'apply to the BA 11·K Mounting Box. The basic BA 11·K includes a 10-1/2 inch
mounting chassis and power system. The 11105S and 11/35S chassis and power system are similar
to the BA 11·K. This manual is used for maintaining and troubleshooting the PDP·11l05S and
PDP·11/35S power system. The manual is organized as follows:

•

Chapter 1 describes the characteristics and specifications ofthe BA 11·K.

•

Chapter 2 describes the system unit configurations, options, and option guidelines applicable
to the BA 11·K.

•

Chapter 3 contains a mechanical description of the BA 11·K and its contents, and describes
the theory of operation.

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•

Chapter 4 describes the BA 11·K power system maintenance procedures, and the replacement
procedures for failed items.

•

Chapter 5 details unpacking and BA 11·K installation.

CHAPTER 1

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BA 11-K CHARACTERISTICS AND SPECIFICATIONS-

1.1 GENERAL
The BA 11-K is a standard, 19-inch, rack-mounted expander box. It is designed to house the DEC
standard system units that make up a PDP-11 expansion system. The expansion system (mounting
box) can contain memory, peripheral controllers, devices, or options compatible with the PDP-11 family.
The BA 11-K is modular in design. This enables a high degree of serviceability with minimum downtime.
~\

The BA 11-K can accept a maximum of five system units. There is a great degree of flexibility in selecting
a system unit configuration, e.g., single and double system units may be mixed.

There are two basic versions of the mounting box; the BA 11-KE for 115 Vac, and the BA 11-KF for
230 Vac. These two variations are the result of two ac input boxes, one for each line voltage. The two
ac input boxes can be interchanged within the same BA 11-K mounting box without any other modifications.
J

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1.2 PHYSICAL CHARACTERISTICS

1.2.1 BA 11-K Characteristics
Figure 1-1 shows the BA 11-K mounted in a rack. It is basically composed of a main chassis and H765
Power System. The BA 11-KE and BA 11-KF are physically identical except for the ac input box in the
H765. The BA l1-KE (115 Vac)contains a 7009811-1 ac input box. The BA 11-KF (230 Vac) contains
a 7009811-2 ac input box.

Figure 1-2 is top view of the physical layout of the BA 11-K. The mechanical and environmental specifications are described in Table 1-1.

Table 1-1
BA 11-K Physical and Environmental Characteristics
Item

Description

Chassis size (with H765 Power System, pop panel,

10.44 in. high, 17.12 in. wide, 26.53 in. deep

and bezel)
1-1

Table 1-1 (Cant)
BA 11-K Physical and Environmental Characteristics

Item

Description

Chassis size (with H765 Power System; without

(

10.44 in. high, 17.12 in. wide, 25 in. deep

console panel and bezel)

Chassis size (without H765 Power System, console

10.44 in. high, 17.12 in. wide, 17.25 in. deep

panel and bezel)

871b

Unconfigured BA ll-K Expander Box chassis
weight

H 765 Power System size

10.38 in. high, 17.~2 in. wide, 7.75 in. deep

Slide extension (three-section slide)

27 in. maximum

Slide weight capacity (BA ll-K fully extended)

150lb

Three-section slide pivotal positions

Horizontal: 45 degrees and 90 degrees (front
panel facing up)

Fan air movement direction

Horizontally toward rear of BA 11-K

Modu Ie slots

22 maximum' using DEC standard configuration backplanes

Operating temperature range

Environmental, shock, and vibration characteristics

To be supplied.

Operating humidity

10 to 90"Al (no condensation)

Cooling efficiency for both fans at 90 Vac, 50 Hz

Temperature rise no greater than 180 F (1 OOC)
from inlet air temperature to exhaust air

1-2

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\~--

7111-24

Figure 1-1 BA 11-K Mounting Box (Top Covers Removed)

1-3

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MAIN CHASSIS

MODULE GUIDES

H765 POWER SVSTEIII!:

H765POWER
SVSTEMCOVER

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Top Vie"';;; l\iIain-Chassis Cover Removed

Figure 1-i SA 11"KPhysical Layout

1-4

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1.2.2 H765 Power System
The H765 Power System is self-contained in its own chassis. It is secured to the main BAll-K chassis
with six screws. Two are special-purpose screws which function as hinges, enabling the H765 to be
swung away from the main chassis during maintenance. The H765 Power System contains five regulators, two fans, an ac input box, a transformer assembly and a power distribution board. Four of the
regulators are self-contained DEC standard modular types. The fifth regulator is a regulator board that
is mounted in the ac input box. Paragraph 4.4 describes the removal procedures for the H765 Power
System. Table 1-2 lists the H765 Power System's physical characteristics.

Table 1-2
H765 Power System Physical Characteristics
Description

Item

H744 Regulators (two)

H765 Power System Contents

H745 Regulator
H754 Regulator
6409730.Y A Regulator

7010014 Transformer Assembly
7009811-1 or -2 AC Input Box with 5410993 .
Power Control Board
5410864 Power Distribution Board
1211714 Box Fans (two)

Fan size

6 in.

Fan type

Ball bearing

Fan capacity at 115 V, 50 Hz

260 cfm at 0 static pressure

Fan efficiency at 90 Vac, 50 Hz

60%

70110014 Transformer Assembly weight

251b

1-5

1.3 ELECTRICAL SPECIFICATIONS

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1.3.1 BA11-KE, BA11-KF Input Power Electrical Specifications
The BA 11-KE and KF are electrically identical except for the ac input box. ABA 11-KE expander box
designation indicates that the input voltage is 115 Vac, and that a 7009811-1 AC Input Box is installed
in the H765 Power System. ABA 11-KF expander box designation indicates the input voltage is 230 Vac

and that a 7009811-2 AC Input Box is installed in the H765 Power System. Tables 1-3 and 1-4 contain
the input power electrical specifications of the BA 11-KE and KF, respectively.

Table 1-3
BA 11-KE Input Power Electrical Specifications
Specification

Parameter
Input power

90-132 Vac, 115 Vac nominal, 47-63 Hz

Inrush current

175 A peak for 10 ms max. at 115 V line voltage

Input power

1380 W at nominal line voltage. 12 A, 115 Vac
(single phase)

Circuit breaker rating

20 A at 115 Vac

AC input noise

To be supplied

Overvoltage transients

To be supplied

Power factor at full load

To be supplied

Frequency stability

To be supplied

AC noise

__ : maximum random noise spike without
causing loss of data or shutdown

500 V peak for a period of 10 ms

Maximum overvoltage transients
1-6

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Table 1-3 (Cont)
SA 11-KE I nput Power Electrical Specifications
Parameter

Specification

Maximum overvoltage

_ _ V overvoltage for a period of 10 cycles

Power fail

H765 Power System is capable of withstanding power
interruptions of any magnitude and duration without
damage. Storage time of power supply at low line and
full load shall be 20 ms ± 3 ms. Storage time is measured
from the time the power outage occurs until the assertion of AC LO signals.

Table 1-4
SA11-KF Input Power Electrical Specifications
Parameter

Specification

Input power

180-264 Vac, 230 Vac nominal, 47-63 Hz

I nrush current

80 A peak for 10 ms max. at 230 Vac line voltage

Input power

1380 W at nominal line voltage, 7 A,230 Vac
(two phase)

Circuit breaker rating

10 A at 230 Vac

AC input noise

To be supplied

Overvoltage transients

To be supplied

Power factor at full load

To be supplied

Frequency stability

To be supplied

AC noise

_'_ : maximum random noise spike without
causing loss of data or shutdown
1-7

- - - .-...

-~----

....- . .- - . - -

Table 1-4 (Cont)

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BA 1.1-KF I nput Power' Electrical Specifications

Specification

Parameter
Maximum overvoltage transients

500 V peak for a period of 10 ms

Maximum overvoltage

__ V overvoltage for a period of 10 cycles

Power fail

H765 Power System is capable of withstanding
power interruptions of any magnitude and duration without damage. Storage time of power
supply at low line and full load shall be 20 ms ±
3 ms. Storage time is measured from the time
power outage occurs until the assertion of AC LO
signals.

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1.3.2 BA 11-K Output Power Specifications
The BA 11-K output power is determined by the rating of the regulators listed in Table 1-5. Due to the
great degree of flexibility and options available, each BA 11-K configuration must be analyzed for total
load requirements. Once the current drain of the options is totaled, it should be compared with the
output currents listed in Table 1-5. (See Table 2-2 for a listing of some of the available options and their

load requirements.) When configuring the expansion system, care must be taken to ensure that the options ~
do not exceed the current capabilities of the regulators.

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1-8

Table 1-5

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SA 11-K Output Power Characteristics
Maximum
Regulator

Voltage and Tolerance

Output Current (Max)

Peak-to-Peak Ripple

H744

+5 Vdc ± 250 mV

25 A (each regulator,

200mV

50 A total)

."
H745

-15 Vdc ± 750 mV

lOA

450mV

H754

+20Vdo± 1 V

5%*

-5 Vdc ± 250 mV

1 A - 8 At

5%*

+ 15 Vdc ± 1.5 V

1.5A

5409730-YA

* At backplane. Typical ripple ±3%.
t Maximum -5 V current is dependent upon +20 V current. It is equal to 1 A plus the current of the

(

+20 V supply, up to a total of 8 A.

1-9

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CHAPTER 2
SYSTEM UNITS, OPTIONS AND HARNESSES

2.1 SYSTEM UNITS

2.1.1

Introduction

A system unit is a framed set of connector blocks attached to the mainframe and connected to the
power supply. Each system unit has an array of six slots into which printed circuit boards or a combination of smaller modules can be plugged. Four slots are reserved for the Unibus connection.

Three types of system units are employed in PDP-11 family processors:

Dedicated - Dedicated system units are prewired and tested for specific functions such as processor, memory, or disk controller.

(

General Purpose - General-purpose system units use a standard backplane wiring which has been

'-~

established for the controllers of small peripherals, such as printers, card readers, and terminals.
Each system unit has four small peripheral controller (SPC) slots with wiring provided for signal
conditioning options. A variety of general-purpose interfaces, communications devices, and options are available for use in these SPC slots.

Blank - Unwired system units are made available for OEM use, enabling custom application.

2.1.2 System Unit Configuration
Using DEC standard logic planes, the BA 11-K has the following configuration capabilities (Figure 2-1).

Five single-system units, 20 slots. (A system unit is a four-slot logic backplane.)

One double-system unit and three single-system units. (A double system unit is a nine-slot logic backplane.)

Two double-system units and one single-system unit.

2-1

,/
\

SLOT PIN
LAYOUT

H765 POWER SYSTEM

SU5 SU4 SU3

SU2 SUI

iiOuBi:.E SU
DOUaLE SU
-DO-U-a-L-E-S-U

eAe
eae
ece
eoe
eEe
eFe
eHe
eJe
eKe
eLe
eMe
eNe
epe
eRe
ese
eTe
eue
eve
I

2
11-2564

Figure 2-1

System Unit Configurations

2-2

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2.1.3 System Unit Installation
The installation of a system unit (SU) requires the items listed in Table 2-1.

Table 2-1
SU Installation Requirements
Quantity

Item

Remarks

Backplane

Power Harness

See Table 2-2

M920 Unibus Jumper Module

Unless the SU is the first installed.in a BA 11-K
expansion box ..

The following steps outline the procedure to be used when installing a system unit.

Install the required number of system units in the BA 11-K and secure them to the mounting boxes,
using the screws provided. The system units are installed with slotA adjacent to the power distribution board.

(
2.

Install a Unibus Jumper Module (M920) from slots A and B of the first SU to adjacent SU slots A
and B (Figure 2-1). This extends the system Unibus continuity to .each logic backplane in the
BAll-K.

The Unibus In should be connected to the first slot (A 1 and B 1) of the first SUo The Unibus Out
should be connected to the last slot of the last SU in the BA 11-K.

Ensure that the M930 Terminator module is plugged into the last SU slot (Slots A and B) when
terminating the Unibus.

Prior to module insertion, check the logic panels for power continuity.

Prior to power turn-on, ensure that the H744 regulators are not connected in parallel.

2-3

Table 2-2a
PDP-11 Family Models and Options
Current Needed

H765 A/B

+5 V (CPU)

Description

Model/Option

+5 V (Options)

-15 V

+20 V

-5V

+15V

Power Dissipated

BA 11-K Power Supply
H744

25A

H744

25A

H745

lOA

H754
5409730-YA

'_5A
1000W

11/05-5

KD11-B

8.0A

MM11-U

6.1 A

2 M920s

2.5A

Total Amperes

16.6 A

0.25 A

0.05 A
4.4A

0.51 A

4.4 A

0.51 A

II.)

11/35-5

0.25 A

0.05 A

250W

KD11-A
KE11-F
KEll-E
KJ11-A
KT11-D
KW11-L

M981
MM11-U
M920
21 A

Total Amperes
-

----

7.3A

4.4 A
-

- _ .. _ - - -

0.51 A
- - -

450W
_ _ _ _ _ _ _ L-.

>~,

r----"'"'r"

Table 2-2a (Cant)
PDP-11 Family Models and Options
Current Needed
Model/Option
*MF11-U/MM11-U

+5 V (Options)

-15 V

+20V

-5V

16 K Sense
Core Memory

6.1 A

4.4 A

0.51 A

(Standby)

(Double SU)

4.5A

0.56 A

0.41 A

16 K Sense

(Active)

Core with Parity

7.3 A

4.4 A

0.51 A

(Standby)

(Double SU)

5.7 A

0.56 A

0.41 A

MF11-L (MM11-L)

8 K Core

(Active)

Memory

3.4 A

6.0A

(Standby)

(Double SU)

1.7 A

0.5 A

MF11-LP (MM11-LP)

8 K Parity

(Active)

Core Memory

4.9 A

6.0 A

(Standby)

(Double SU)

1.7 A

0.5 A

MM11-S

Same as MM 11-L
Except in SU
Configuration (1 SU)

*Non-I nterleaved.

+5 V (CPU)

(Active)

MF11-UP/MM11-UP

I\J

Description

+15 V

Power Dissipated

Table 2-2b
PDP-11 Family Options
Power
Option
AA 11-D

Mounting Code
1 SU

Current Needed

Power

Description

Harness

+5V

Digital to Analog

7009562

3.0A

30W

-15 V

+20V

-5V

+15V

Dissipated

Converter Subsystem
BA614

(AA 11-D)

DI A Converter

3.0A

30W

BM792-Y

SPC

Bootstrap Loader

0.3A

CD11-A/B

1 SU

1000 CPM, 80 Col.

7010117

2.5 A

28W

7010117

2.5A

28W

1.5 A

15W

1.5 A

15W

4.0A

40W

Card Reader Controller
CD11-E

1 SU

1200 CPM, 80 Col.
Card Reader Controller

I\J

C,
CM11

SPC

200 CPM, 80 Col.
Card Reader Controller

CR11

SPC

300 CPM, 80 Col.
Card Reader Controller

DA 11-DB

1 SU

Unibus Link

DA 11-F

1 SU

Unibus Window

7010117

5.0A

50W

DB11-A

1 SU

Bus Repeater

7009562

3.2 A

32W

DC11-A

1 SU

Dual Clock and

7010117

0.2 A

2.0A

20W

System Unit
DC11-DA

(DC11-A)

Full Duplex Module Set

,..~~

ft.'

If
'\

,f<'

I~r--:

::-

.~.

(

Table 2-2b (Cont)
PDP-11 Family Options
Power
Option
DD11-B

Mounting Code
1 SU

Description
Peripheral Mounting

Power

Current Needed

Harness

+5V

-15V

+20V

-5V

+15V

Dissipated

7010117

7010118

8.4 A

0.42

93W

7010117

5.0A

0.48

57W

.15 A

Panel
DHll-A

DLB SU

Prog. Async 16-Line
Multiplexer

DJl1-A

1 SU

Async 16-Line MUX
,

DL 11

SPC

Async Interface

1.8 A

DM11-B

(DH11)

16-Line Modem Control

2.8A

28W

DMll-D

(DH11)

Line Adapter

2.8A

28W

DNll-A

1 SU

Auto Calling

.016

21 W

I\J

.!..J

7009562

System Unit
DP11-D

1 SU

Half/Full Duplex

7009562

2.5A

0.10A

27W

7010117

5.7 A

0.07 A

0.04 A

60W

7010117

5.7 A

0.07 A

0.04 A

60W

Sync I nterfacl!
DPll-C

(DPll-D)

Data/Sync Register
Extender

DPll-K

(DP.ll-D) .

Internal DP11 Clock

0011-0

1 SU

Full/Half Duplex

Sync Interface
DOll-E

1 SU

Full/Half Duplex
Sync Interface

Table 2-2b (Cont)
PDP-11 Family Options
Power

Option

Mounting Code

Description

DQ11-K

(DQ11-D/A)

Crystal Clock

DR 11-B

SPC

General Purpose DMA

DR 11-C

1 SU

General Purpose

Power

Current Needed
-15V

+20 V

-5V

+15V

Dissipated

Harness

+5V

7009562

3.3A

33W

1.5 A

15W

Digital Interface
DU11-D

SPC

Full/Half Duplex

2.2A

0.06 A

24W

105W

.Sync Prog. Interface

1.0

DBL SU

KG11-A

SPC

Comm Arith Unit

1.5A

15W

KW11-L

(CPU)

Line Clock

O.SA

KW11-P

SPC

Prog LineClk

1.0 A

10W

LC11-A

SPC

LA30 Control

1.5 A

15W

LP11-R

SPC

1200 LPM Printer

1.0 A

10W

LP11-S

SPC

900 LPM Printer

1.0 A

10W

LP11-W

SPC

240 LPM Printer

1.5 A

15W

LP11-V

SPC

300 LPM Printer

1.5 A

15W

LS11-A

SPC

60 LPM Printer

1.5 A

15W

LV11-B

SPC

Electrostatic Printer,

1.5A

15W

I\.)

S.5A

DV11

500 LPM
._-

(~.

,~~'\

(-~,

Table 2-2b (Cont)
PDP-11 Family Options
Current Needed

Power
Option

Mounting Code

Description

Harness

+5V

-15V

+20V

Power
-5V

+15V

Dissipated

MR11-DB

2 SPC

Bootstrap

0.6 A

PC11

SPC

Paper Tape

1.5A

15W

PR11

SPC

Paper Tape (Reader)

1.5A

15W

RH11

DBLSU

RK11-D

Disk and Cntrl

7.5A

75W

TA11-A

SPC

Dual Cassette

1.5A

15W

7010115

I'.l

Interface

-------- - - - - - - - - -

2.2 OPTIONS
The BA ll-K expander box has the capability of accepting 22 modules. This allows for the various

(

combinations of system unit configurations described in Paragraph 2.1. Table 2-2 lists some of the
PDP-ll family options available and the unique characteristics of the options.
Two factors should be considered when installing or changing an option. First, various options have
unique power harnesses. Table 2-2 lists the harnesses required for the appropriate option. Secondly,
care must be taken to ensure that the options selected do not exceed the regulator outputs listed in
Table 1-5. The 'fnaximumtotal BA ll-K output power is 1000 W. This value represents the
transformer secondary dc watts. Paragraph 1.3.2 describes the procedure used to determine a compatible power configuration.
2.3 POWER DISTRIBUTION WIRE COLOR CODING
Table 2-3 lists the standard colors used for dc power and signal distribution to the backplanes.

Table 2-3
Power Distribution Wire Color Coding
Color of Wire

DC Power/Signal
Ground

Black

Line Clock (l TCl)

Brown

,DC lO

Violet

AC lO

Yellow

+5V

Red

-5V

Brown

+15 V

Gray

-15 V

Blue

+20 V

Orange

2.4 CABLE ROUTING

To Be Supplied

2-10

(

To Be Supplied

Figure 2-2 Unibus Connection

2-11

(

CHAPTER 3
H765 POWER SYSTEM

3.1

INTRODUCTION

This chapter provides mechanical and functional descriptions of the H765 Power System. A detailed
electrical interconnection diagram is included. The regulator circuits, which are part of the H765
Power System, are discussed in detail.

3.2 MECHANICAL DESCRIPTION
The power system consists of two H744 Regulators (+5 V), an H745 Regulator (-15 V), and H745
Regulator (+20 V, -5 V), a 5409730-YA Regulator (+15 V), a 7010014 Transformer Assembly, a
7009811-1, -2 AC Input Box, a 510864 Power Distribution Board, and 1211714 Fans. The contents
of the power system are primarily housed in a welded steel chassis.

(

The chassis is rectangular and measures approximately 7-3/4 in. long by 10-1/2 in. high by 17 in. wide.
The top power system cover is held in place by six screws. The main structural member contains cutouts and drill holes which enable screws to be inserted for securing the regulators, ac distribution box,
transformer assembly, and fans. Cutouts for the regulators allow the regulator ON indicators to be
monitored and the regulator output voltages to be adjusted.

3.2.1

H744, H745, and H754 Regulators

These regulators are secured to the H765 Power System chassis with three Phillips head screws. They
are installed with the heat sink upward. The mounting screws pass through the H765 chassis holes and
screw into the regulator. A plastic (Lexon) cover is installed on the component side of each regulator .
.This permits visual inspection of the regulator components once the regulator is removed from the H765
chassis. The fuse, which is located on the component side, is accessed by removing the plastic cover.
Each regulator contains one potentiometer, with the exception of the H754, which contains two potentiometers. An output indicator lamp is located next to the potentiometer. The output of the regulators
is terminated in a Mate-N-Lok connector.

3-1

(

3.2.2 7010014 Transformer Assembly
This transformer assembly is located in the center of the H765 chassis. Two capacitors, two varistors,
and two terminal boards are mounted directly on the transformer. The transformer base plate is
used to bolt the transformer to the chassis. The area around the transformer is open, enabling ample
air flow from the two fans across the transformer. A thermistor is mounted directly to the transformer frame, enabling over-temperature monitoring. Output leads from the transformer, which go to
other modules, are terminated in Mate-N-Lok connectors. A cable clamp is used to secure these leads
to the chassis.

3.2.3 7009811-1, -2 AC Input Box
The ac input box is mounted in the center of the power supply chassis with three Phillips head screws.
The center rear of the power supply chassis is cut out, exposing the rear of the ac input box. This
enables easy access to the ac line cord, circuit breaker, and remote power control Mate-N-Lok. The
5410993 Power Control is physically mou nted in the ac control box.

(

3.2.4 1211714 Box Fan
Two six-inch ball bearing fans are utilized in the H765 Power System. They are mounted in the chassis
between the module boards and regulators. Each fan is secured to the chassis with two screws.

3.2.5 5410864 Power Distribution Board
This power distribution board is a multilayer printed circuit board. It contains 12 Mate-N-Lok connectors
connected directly to the board and four Mate-N-Loks connected to flying leads. The power distribution
board is grounded using a ground tab which is connected to a flying lead. The power distribution board
is mounted on the bottom rear of the BA 11-K chassis; four screws are used to fasten it in place.

3.3 SYSTEM FUNCTIONAL DESCRIPTION
A functional block diagram of the power system is shown in Figure 3-1. Assume that the line cord is
plugged in and the circuit breaker is on; line voltage is applied to the ac input box. The ac input box
contains a circuit breaker, relay, and power control circuit. The cir~uit breaker is used as an ON/OFF
',,;

switch as well as an overcurrent protection device. The relay and power control circuit allows remote

3-2

,~,

,/---~

I
:

IH765PowE'RSUPPLY- -

AC INPUT
PLUG

4.J

....-...o----oia
CBI

I
7010014 TRANSFORMER
ASSEMBLY

TRANSFORMERIIIITRANSFORMER I
PRIMARIES
SECONDARIES

---1

----

~009811 (-1 OR-2)
AC INPUT BOX

TO OR FROM
EXTERNAL
POWER
CONTROL

J3
1 2 31
4 5 61 IDENTICAL
TO
7 8 91
10 11 12' J5,7,9,11
1314 15

5410864 POWER
DISTRIBUTION J3
BOARD
28 VAC
PllJl
SECONDARIES (4 SETS)

I----··-~
i

r---+-~I_'"

i I

+20V,-5V
TO
J3,5,7,9,11 J5

+5V
... TO
J3,5,7

..
28VAC

5409730-YA
+15V D,C REGULATOR
+5V

tAl

-+-'---1'-+.. TO

I.C

J9,11

: '

i!
BACKPLANE

-15V
...
TO
J3,5,7,9,11

J
JI2
J12f {" [i'T'f[3]IDENTICAL TO
+15V
, [iI]]§] ,J4,6,8,10
T<l
J3,5,7,9,11
LTC ,AC LO,DC LQ,
TO
J4,6,8.IO,12
+5

I
1L __ _
~

THIS AREA
ACCESSIBLE AT
REAR OF MOUNTING
BOX

-- -

- -------- - - - - - -- -- --'-

~----~------------------------~vr------------------------------~
THESE CONNECTORS ACCESSIBLE
BY SWINGING BACK POWER SUPPLY

'-----'--+ TO
L _ _--'-_ _ _ _
'" CONSOLE

THESE CONNECTORS ARE ACCESSIBLE
FROM BOTTOM OF MOUNTING BOX
11- 2551

Figure 3-1

Power System Functional Block Diagram

, i

' - - - ,---------'

I
I

-------,--------~----------------------------------,-----_r__-----

-~--------.-----

(

control of ae power'to
thi;l transformer assembly by means of a key switch or thermal switch.
The
.
\
,

transformer assembly steps down the voltage to approximately 28 Vdc and routes it to H744, H745,
"

H754, and 5409730-YA regulato,rs. In addition~ the transformer 'assembly routes 115 Vac to box
fans 1 and 2. The regulated de outputs of the regulators are applied to the power distribution board,
where they are distributed to the various backplane connections.

3.4 SYSTEM CIRCUIT DESCRIPTION
This parayraph describes in detail the ac input box, transformer assembly, regulators and power distribution board. Figure 3-2 illustrates these circuits and their interrelationship;

3.4.1 AC I nput Box
The 115 V (7009811-1) and 230 V (7009811-2) ac input boxes are functionally identical. They differ
physically in their components and in the way they are connected to the transformer assembly. Figure 3-3
is a simplified schematic of the '115 Vac power configuration. In this configuration, the power transformer
windings'are connected in parallel. In the 230Vac power configuration (Figure 3-4), the power transformer windings are connected in series.

,Utilizing the 115 Vac input box(7009811-1), the input line voltage is applied via a 20 .A. circuit breaker
(Figure ~-2) to relay K2, 'and':tra~sformer T1 on the p~wer cont~olboard. Transformer T1 steps down
I

....

the voltage to 24 Vac. The 24 Vac is rectified and applied to relayKl.. To energize K1 (Figure 3-5), the
remote power switch contacts must beclosed.'Energizirig K 1 completes the path to K2, switching the 115
Vac to the transformer assembly. i'h~ normally open thermal switch (TS1) (located in the transformer
assembly) closeswhen an over-tempe~~{ure c~ndltio~ is sensed.' Closing TS1 applies 24 Vdc to
half the K 1 relay coil. This creates two ~¥posing fields, causing K 1 to deenergize. Oeenergizing K 1
interrupts the ac power to the transformer:assembly. The varistor (06 or 07) across the coil (Figure 3-2)
of K2 suppresses voltage spikes in excess of 150 Vac for AC I nput Box 7009811-1, and 275 Vac for AC
Input Box 7009811-2.

3.4.2 Transformer Assembly
The primary function of the transformer assembly is to step down the 115 Vac or 230 Vac input voltage,

(

(Figure 3-2)'to 28 Vac. There are five separate secondary transformer windings, one for each regulator.

11.5V 7009811-1

TRANSFORMER ASSEMBLY

(

AC INPUT BOX

cel

;-r..,....
L
I
I -C
or-_

BLACK
115V
{
NOMIN,AL
47-63H~

GRN
WHITE -=k:-

........

J5
~I ~

1)..1

2 2

5,6,7,8

I 2;3,4 I

~',

L....

K2
'\..2,3,4

3 ;3
44

5,~,7;8

' - l-

I....,.,

NOTE:
Transformer windings are c;:anriec::ted in parallel to t,he inPut power.
11- 2546

Figure 3-3 115 V Power Configuration

230V 7009811'-2

TRANSFORMER

AC INPUT BOX
CBI
PHASE (BLACK) ::1"_..,-0

230V
NOMINAL
47-63HZ

I
I
II
I
I
I
I
I
,I

GRN

PHASE(WHITE)

A_iK2

~I t.I5

T-!',
1,2,3,4

2 2

51 6,7,8

' 'Te2

ASSEMBLY

(

:,.;;.

1,2,3,4'

:5 ;3
44

5,6,7,8

I....,.,

I-.-

NOTE:
'Transformer windings are connec;:ted in sedes to th,e'input power.
11-2545

"Figure 3-4 2:30 V Power Configuration

(
3-6,

(
54 -10993. AC POWER CONTROL BOARD'

~ FAST ~ON TABS
11
TO 230VAC OR 115 VAC
RELAY COIL K2

9
AC REFERENCE

•

::-r:
J

.. I '

r,;...-'----... ..,
I

.
L _____
.....J!
10

115{

1
VAC

230 VAC

24VDC

I
- i

!L _____ -1!

..,.

THERMAL (NO.)
SWITCH

I
I
I
I

'K1

24YDC

r------,

I ....

......

. ~~

2.7 kn

REMOTE POWER
SWITCH (NC).
(OPTIONALf

T
NOTE:

(

THERMAL SWITCH AND KEY SWITCH ARE NOT PART OF
AC POWER CONTROL BOARD

11-2547

Figure 3-5 Power Control Simplified Diagram

,<:: '

3-7

3.4.3 5409730-YA Regulator
The 5409730-YA Regulator, shown on drawing C-CS-5409730-YA-1, contains a +15 Vdc supply. The dc
supply receives 20 to 30 Vac from the secondary of transformer T1. The ac input isfull-wave rectified
by diode bridge D1. The resultant dc is applied to Darlington voltage regulator Q 1 through fuseF 1. The
bias on Q1 is controlled to provide +15 Vdc at output pins 2 and 3, with respect to output pins 4,5, and
6. The output of this supply is rated at 1.5 A. The following paragraphs describe the clock output, AC LO
and DC LO circuits, AC LO sensing, and DC LO sensing.

CLOCK Output - The CLOCK output is derived from one leg of full-wave rectifier bridge D 1, by
voltage divider R 10 and R 11, and Zener diode D2 (drawing C-CS-5409730-Y A-1). The CLOCK output is a 0 to +5 V square wave, at the line frequency of the power source (47 to 63 Hz). The CLOCK
output is used to drive the KW11-L Line Frequency and KW11-P Real-Time Clock options.

(

AC LO and DC LO Circuits - The 20-30 Vac input from the secondary of transformer T1 is applied
to the AC LO and DC LO sensing circuits. The sensing circuits are shown on drawing C-CS-5409730-0-1.
The ac input is rectified by diodes D8 through D 11, and filtered by capacitor C3. A common
reference voltage is derived by resistor R 18 and Zener diode D 12. Both sensing circuits operate
similarly; each contains a differential amplifier, a transistor switch, and associated circuits. The
major difference is that the base of Q6 in the AC LO circuit differential amplifier is at a slightly
lower value than that of Q9in the DC LO differential amplifier. The operation of both sensing
circuits depends on the voltage across capacitor C3. For AC LO and DC LO timing during power up
and power down, refer to Figure 3-6.

AC LO Sensing - The 20-30 Vac input is rectified and stored in capacitor C3, which will charge
and discharge at a known rate whenever the ac power is switched on or off. Thus, the voltage applied to the emitters of differential amplifier Q6/Q7 through R 17 is a rising or falling waveform of
known value. For example, when power fails or is shutdown, the dc voltage decays at a known rate,

(
3-8

(

I________________~__________
L.

I
I

AC POWER
DOWN

."T"--.. -----

+15V

I------+1-------L

AC 1.0

!-.

.....!

~5m$

Minimuni

'Snis' '-,.+1--·- - - - - - _ - , D C ,L.O

-.:

r-t-

Minimum
---.I . 1..,,-, ms Minimuni
AC POWER DOWN

."-2~6

___________________________ AC POWER

~_~.....
,-

---=+1-1".

__- - - .. - , ' - - - - _ - +15V

30 ms .

IMinimum

"J, I

.------.--..;---------'- bC 1.0
2ms
!--Minimum

I
I

AC LO

......I

1.-2ms Nominal

AC POWER UP

"-2567

Figure. 3-6 . 5409730-YA PowerUpand Power Down.

' ... : , , : , '

3-9

as determined by the RC time constant. If the voltage decreases to the point where the base of 06

(

becomes negative with respect to the base of 07, the increased forward bias on 06 causes it to conduct more, and the resultant decrease in07 causes it to cut off. This removal of voltage across R 16
causes 05 and 04 to cdi'lduct. The At LO line at pin 8 is grounded.

DC LO Sensing - The DC LO sensing circuit operates in a manner similar to that described for AC LO.
The difference between these circuits is the voltage level at which they trip. For example, if the ac
input starts to decrease, as a result of a power failure or shutdown, the AC LO lines are grounded
before the DC LO lines. As power is restored, the ground is removed from the DC LO lines before
it is removed from the AC LO lines.

NOTE
AC LO and DC LO indicate the status of the 5409730.YA
as described in the preceding paragraphs. A H744, H745,
or H754 failure will not generate an AC LO or DC LO signal.

(

3.4.4 H744 +5 V Regulator
Two H744 +5 V Regulators are used in the basic H765 power system. The H744 circuit schematic is
shown in drawing_---.;_ _ _ . The following paragraphs describe the regulator circuit, overcurrent
sensing circuit, and ovelV0ltage crowbar circuit.

Regulator Circuit - The 20-30 Vac input is full-wave rectified by bridge 01 to provide de voltage
(24 to 40 Vdc, depending on line voltage) across filter capacitor C1 and bleeder resistor R 1. Operation centers on voltage regulator E 1, which is configured as a positive switching regulator. A
simplified schematic of E 1 is shown in Figure 3-7. E 1 is a monolithic integrated circuit that is used
as a voltage regulator. It consists ota temperature-compensated reference amplifier, an error amplifier series pass power transistor, and the output circuit required to drive the external transistors.
In addition to E1, the regulator circuit includes pass transistor 02, predrivers03 and 04, and level
shifter 05. Zener diode 02 is used with 05 and R2 to provide +15 V for E1. 05 is used as a level
shifter; most of the input voltage is absorbed across the collector-emitter of 05. This is necessary
because the raw input voltage is well above that required for E1 operation. While this +15 V input

lJ
3-10

(

FREQUENCY
COMPENSATION

V+
INVERTING
INPUT o------------+----,
V REF 0---_1-.,---------,

r------'--'----Ov~

...------0 V OUT
L----,---,-,--ov 1,
NONINVEI%~~~ 0-------------+---'

VA - Voltage Reference Amplifier
,8,- Error Amplifier
C -Current Limiter

'CURRENT CURRENT
LIMIT
SENSE

Simplified Schematic

FREQ COMP

CURR LIM
CURR SENSE

V+

INV OUTPUT

Vc
Vout

NON -INV OUTPUT

Vref

V-

Pin Designations
,

(

Figure 3-7 Voltage Regula~orE1, Simplified Diagram

3-11

t -1895

is supplied, 02, Q5, and R2 retain the ability to switch pass transistor Q2 on or off by drawing
current down through the emitter of Q5.

(

The output circuit is standard for most switching regulators and consists of free-wheeling diode
05, choke coil L 1, and output capacitors C8 and C9. These components make up the regulator
output filter. Free-wheeling diode 05 is used to clamp the emitter of Q2 to ground when Q2
shuts off, thus providing a discharge path for L 1.

In operation, Q2 is turned on and off, generating a square wave of voltage that is applied across 05
at the input of the LC filter (L 1, C8 and C9). Basically, this filter is an averaging device, and the
square wave of voltage appears as an average voltage at the output terminal. By varying the period
of conduction of Q2, the output (average) voltage may be varied or controlled, thus supplying
regulation (Figure 3-8). The output voltage is sensed and fed back to E1, where it is compared
with a fixed reference voltage. E1 turns pass transistor Q2 on and off, according to whether the
output voltage level decreases or increases. Defined upper and lower limits for the output are approximately +5.05 V and +4.95 V.

During one full cycle of operation, the regulator operates as follows: Q2 is turned on and a high

(

voltage (approximately +30 V) is applied across L 1. I f the output is already at a +5 V level, then
a constant +25 V would be present across L 1. This constant dc voltage causes a linear ramp of
current to build up through L 1. At the same time, output capacitors C8 and C9 absorb
this changing current, causing the output level (+5 V at this point) to increase. When the output,
which is monitored by El, reaches approximately +5.05 V, E1 shuts off, turningQ2 off; the emitter
of Q2 is then clamped to ground. L 1 discharges into capacitors C8, C9, and the load. Predrivers
Q3 and Q4 are used to increase the effective gain of Q2, thus ensuring that Q2 can be turned on and
off in a relatively short period of time.

Conversely, once Q2 is turned off and the output voltage begins to decrease, a predetermined value
of approximately +4.95 V will be reached, causing E1 to turn on; E1 in turn, causes Q2 to conduct,
beginning another cycle of operation.

Thus, a ripple voltage is superimposed on the output and is detected as predetermined maximum
(+5.05 V) and minimum (+4.95 V) values by E 1. When +5.05 V is reached, E1 turns Q2 off; when
+4.95 V is reached, E1 turns Q2 on. This type of circuit action is called a ripple regulator.
3-12

(

POWER
ON

OFF

I
I

I
I
I

+39v]-r
OV·

n n----I

I
I
I

Q2 ON
Q2 OFF

I ,5.05V

+:: ___ ~~~~~rro
11-0098

Figure3-8 H744 Regulator Waveforms

(
2.

+5 VOvercurrent Sensing Circuit - The overcurrehtsensing circuit consists of 01 i R3 through R6,
R25, R26, programmable unijunction 07, and C4. TransistorQ1 is normally not conducting;
however, if the output exceeds 30 A, the forward voltage across R4 is sufficient to turn 01 on,
causing C4 to begin charging. When C4 teaches a value equal to the voltage on the gate of 07,
07 turns on andE 1 will be biased off, turning the pass transistor off. Thus, the output voltage is decreased as required to ensure that the output current is maintained below 35A (approximately) and
thatthe regulator is short circuit protected. The regulator continues to oscillate in this. new mode
until the overload condition is removed. C4 then discharges until E 1 is again allowed to turn on
-----ana-the cycle repeats.

+5 V Overvo.ltage Crowbar Circuit - The following components comprise the overvoltage crowbar
circuit: Zener diodeD3, silicon-controlled rectifier (SCR) D7, D8, R22, R23, C7 and 06. Under
normal output voltage conditions, the triggerinputto SCR D7 is at ground because the voltage
across Zener diode D3 is less than 5.1 V. If the output voltage becomes dangerously high (above

(

6.0 V), diode D3 conducts, and the voltage drop across R23 draws gate current and triggers the SCR.
The SCR fires and short circuits the +5 V output to ground.

3-13

(
3.4.5 H745 -15 V Regulator
Operation of the H745 is basically the same as that of the +5 V regulator (drawing _ -_ _ _ ).
Input power.(20 t030Vac is taken from the transformer secondary and input to full·wave bridge 01,
whose output is a variable 24 to 40 V dc input across capacitor C 1 and resistor R 1.

-15 V Regulator Circuit - Regulator operation is almost identical to that of the +5 V regulator;
however, the +15 V input that is required for El operation is derived externally and is input across
capacitor C2 to + 1, and the inverting and non inverting inputs to E 1 are reversed. I n addition, the
polarities of the various components are reversed. For example, Q5, which is used as'a' "level shifter,"
is an NPN transistor on the +5 V regulator; a PNP is required on the -15 V regulator, thus allowing
the regulator to operate below ground (at -15 V).
'>

Under normar operating conditions, regulator operation centers around linear regulator Eland pass
transistor Q2, which is controlled by E1. Predetermined output voltage limits are -14.85 V minimum .
and -15.15 V maximum. When the output reaches ...J 5.15 V, E 1 will shut off, turning Q2 off, and
L 1 discharges into C8 and C9. When the output reaches-14.85 V, El will conduct, causing Q2 to
turn on, thus increasing the output voltage.

-15 V Overcurrent Sensing Circuit - The -15 V regulator overcurrent sensing curcuit is basically
made up of the same components used in the +5 V regulator, except 01 is an NPN transistor in the
-15 V regulator. Q 1 is normally not conducting; however, once the output exceeds 15 A, Q 1 will
turn on and C3 will charge. When C3 reaches the same value as the gate of Q7, E 1 will be biased
off, which turns Q2 off, thereby stopping current flow and turning the -15 V regulator off. Thus,
the regulator is short circuit protected.

...;.15 V Overvoltage Crowbar Circuit.,.... When SCR 05 is fired, the -15 V output is pulled up to
ground and latched to ground until input power or the +15 V input is removed. A negative slope on
the +15 V line can be used to trip the Crowbar for power down sequencing, if desired.

3-14

(

~~~~

-------------~-----

3.4.6 H754 +20, -5 V Regulator
One H754 Regulator is used in the basic H765 Power Supply. The H754 circuit schematic is shown in
drawing _________ . The following paragraphs describe the regulator circuit, overvoltage crowbar
circuits, overcurrent sensing circuits, and voltage adjustment procedure.

Regular Circuit ~The circuit (schematic D-CS-H754-0-1) is similar to that of the other regulators:
like the H746, it has a voltage doubler input, but the output consists of two shunt regulator circuits,
one for the +20 V, the other for the -5 V. The +20 V shunt regulator consists of transistors 04,
010, and 011; the -5 V shunt regulator consists of 06 and 09. 010 and 09 are the pass transistors.

The output of the basic regulator is 25 V (-5 to +20 V). The shunt regulators are connected across
this output, with a tap to ground between pass transistors 09 and 010. The voltage at the bases
of 06 and 04 will vary with respect to ground, depending on the relative amount of current drawn
from the +20 V and -5 V outputs of the regulator. If the +20 V current increases while the -5 V
current remains constant, the output voltage at the +20 V output will tend to go more negative with
respect to ground; this will also cause the.:.:..5 V output to go more negative, since the output of the
basic regulator is a fixed 25 V. This change is sensed at the bases of 06 and 04: 06 will conduct,
causing 09 to conduct also, thus increasing the current between -5 V and ground until the balance
between the +20 V and the -5 V is restored. At this time, neither 06 nor 04 will be conducting.
If the -5 V current increases, 04 and 010 will conduct to balance the outputs.

Overvoltage Crowbar Circuits - There are two crowbar circuits in the H754: 07 and its associated
circuitry for the +20 V, and 012 and its circuitry for the -5 V. Either one will trigger SCR D9.

Overcurrent Sensing Circuit -

The overcurrent circuit comprises 01,08,013, Q 14, and associated

circuitry. The total peak current is sampled through R4. When the peak current reaches approximately
14 A, 01 turns on sufficiently to establish a voltage across R7 and R38, thus firing 08. This pulls
the voltage on pin 4 of the 723 up above the reference voltage on pin 5, thereby shutting off Q2.
D6 now conducts, and the current through R37 turns on 014, which turns on 013. This keeps 08
on for a time which is determined by the output voltage and L 1. This action, in turn, allows the
off-time to increase as the overload current increases, thereby changing the duty cycle in proportion to
thedoad. The output current is thus limited to approximately 10 A.

3-15

. - ....

·,'
--~~--

-------~-

..---------.

-----------"_.-.---- - - - - - - - - - - - - - - -_._--_._-----...

_--_..--

---- ..

~.-

..-.,----

-------

----------

~.-.-~~-----

(

Voltage Adjustment - The +20 V adjustment is located on the side of the H754; the -5 V potentiometer is on the top, next to the connector. To set the output voltages, power down, disconnect
the load, power up, and adjust for a 25 V reading between the+20 and -5 V outputs with the 20 V
potentiometer. Then set the -5 V between its output and ground. Power down, reconnect the
load, power up, and then check and adjust the outputs again. This procedure is necessary because the
+20 V potentiometer (R17) actually sets the overall output of the regulator (25V from +20V to
-5 V), while the -5 V adjustment (R21) controls the ..;....5 V to ground output. (See schematic drawing

-----_.)
3.4.7 Power Distribution Board
The power distribution board (Figure 3-9) performs two primary functions: it routes the transformer
assembly secondary output voltages to the regulators and routes the dc outputs of the regulators to the
backplane.

Routing voltage to the regulators is accomplished via Mate-N-Lok J1/P1 and an etch on the power distribution board. Mate-N-Lok P1/J1 routes 28 Vdc from four separate transformer secondaries to H745,
H754, and both H744 Regulators. The etch routes +15 Vdc from 5409730-YA Regulatorto the H745

(

Regulator.

The regulator outputs are routed as follows:

H745 Regulator 1, -15 Vdc output, is routed via the power distribution board etch to 15-p.in
Mate-N-Loks J3, J5, J7, J9, and J11.

H744 Regulator 2, +5 Vdc output, is routed via the power distribution board etch to 15-pin
Mate-N-Lo\<s J9" and J11. H744 Regulator 3, +5 Vdc output, is routed via the power distribution
board etch to 15-pinMate~N-Loks J9 and J11. A unique configuration of the power system is
that two H744 Regulators cannot be connected in parallel. Figure 3~10 is a simplified diagram
illustrating the correct H744 to power distribution board configuration.

H754 Regulator 4, +20Vdc, -5 Vdc outputs, are routed via the power distribution board etch to 15pin Mate-N-Loks J3, J5, J7, J9, and J 11.

(\
3-16

i~\

~'.

MATE- N-LOKS Jll, J9, J7, J5,J3

MATE-N-LOKS J12, JIO, J8,J6,J4

PIN DESIGNATIONS

13 10 7

14 II

15 12 9

SIGNAL

PIN DESIGNATIONS

SIGNAL

1.
2.

+5V
+15V
+20V
+5V

1.
2.
3.

LO GND
LTC (Line Clock)
DC LO
AC LO
Not Used
Not Used

3.
4.

5.
6.
7.
8.
9 ..

10.
11.
12.
13.
14.
15.

5 2'
6

GROUND
Not Used
GROUND
GROUND
GROUND
Not Used
GROUND
Not Used

4.
5.

-15V
-5V
Not Used

ctl

.......
-..J

§1§1813131·~~
~.2:~S!a~

D::D::w..J..J w
zlzlcl~I~lo
ClClD::IllIllD::

-~----

f----'~-o~-----'r(f~-~-~p-Q~~:---CC;pORtlT('BRNJ 'p
JII

Jl0

11-2570

Figure 3-9 Power Distribution Board

(

H744

GNO +5V

POWER PISTRIBUTION BOI)R

JI2

JI1

o
J8

o
J6

0,
J4

J3
11-2565

Figure3-10 H744 Connection Dia!;lram

(

(
3.18

(

5409730-YA Regulator, +15 Vdc output, is routed via the power distribution board etch to
H745. The +15 Vdc is also routed via the etch to 15-pin Mate-N-Loks J3, J5, J7, J9, and J11.
5409730-YA LTC, AC LO, and DC LO outputs are routed via the etch to six-pin Mate-N-Loks
J4, J6, J8, J10, and J12.

The de and signal outputs of Mate-N-Loks J3 through J 12 are routed to the backplane via a
power harness. Table 2-2 lists the power harnesses required for the appropriate option.

3-19

(

CHAPTER 4
MAl NTENANCE

SA 11-K maintenance procedures are divided into two categories: pre"entive maintenance and corrective
maintenance. Corrective maintenance should be performed to isolate a fault or malfunction and to make
: necessary adjustments and/or replacements. 'Diagnostic programs that' test the functi()nal units of the
system and special calibration and test p'rocedures aid in performing corrective maintenance. This chapter
describes the equipment and procedures needed for performing corrective and preventive maintenance.

4.1

MAINTENANCE EQUIPMENT REQUIRED

Maintenance procedures for the SA 11-K require the standard equipment (or equivalent) listed in
Table 4-1.

4.2 PREVENTIVE MAINTENANCE'

4.2.1 General
Preventive maintenance consists of specific tasks performed periodically to prevent faiiu;escau~ed
;

by minor damage or progressive deterioration due to aging. Apreventive maintenance log book should
be established and necessary entries made according to a regular schedule. This data, complied over an
extended period of time, can be very useful in anticipating possible componendailure.
Preventive maintenance tasks consist of mechanical and electrical checks. All mainterianc~ ~hedu'les
.

st\ould be established according to environmental conditions at'the particular installation site., Mechanical checkssho~ld be performed as often as required to enable fans and air filters to f~nction effi~iEmtIY.
All other preventive maintenance tasks should be performed on a regular schedule determinedby:reliability
requirements. A recommended schedule is every 1000 operating hours or every three months, whichever
occu rs fi rst.

4.2.2 Physical Checks
The following is a list Of the steps required f~r mechanical~hecks and physical care of the SA 11-1<.

(
4-1

----

------------------

---------

(

Check all fans to ensure that they are not obstructed in any way.

Inspect all wiring and cables for cuts, breaks, frays, deterioration, kinks, strain, and mechanical
security. Repair or replace any defective wiring or cable covering.

3..

Inspect the following formeGhanical security: lamp or LED holder assemblies, jacks, connectors,
switches, power supply regulators, fans, capacitors, etc. Tighten or replace as required.

Inspect power supply capacitors for leaks, bulges, or discoloration. Replace as required.

Table 4-1
Maintenance Equipment Required
Equ ipment or Tool
Oscilloscope

Manufacturer

Model, Type, or Part No.

Tektronix

453 (or equivalent)

DEC Part No.
29·13510

(

DVM
VoltlOhmeter (VOM)

Triplett

Diagonal Cutters

Utica

47·4

29·13460

Diagonal Cutters

Utica

466·4 (modified)

29·19551

Miniature Needle·Nose

Utica

23·4-1/2

29·13462

Wire Strippers

Millers

101S

29·13467

Solder Extractor

Solder Pullit

Standard

29·13451

Soldering Iron (30 W)

Paragon

615

29·13452

Soldering I ron Tip

Paragon

605

29·19333

29·13510

Pliers

4.3 MAINTENANCE PROCEDURE
4.3.1

H765 Power System Fault Isolation

The H765 Power System (Figure 3·2) 'consists of field replaceable modules. Once a power system failure
is discovered, the following steps and associated flowchart (Figure 4·1) can be utilized to isolate to a
faulty module:
4-2

AT POWER DISTRIBUTION
BOARD MATE-IIl-LOK (J3,J5,J9, OR Jlll
MEASURE REGULATOR
VOLTAGES PER TABLE 4-2

NO
TABLE 4-2
YES

FAILURE MOST LI KEL Y
IN REGULATOR,
TRANSFORMER ASSEMBLY,
NO
>--_-1 POWER DISTRIBUTION
BOARD, OR LOAD. ISOLATE
BY CHECKING REGULATOR
INPUT AND OUTPUT.

CHECK FOR
FAULTY WIRING
TO BACKPLANE'

AT AC INPUT BOX SET CBl TO OFF

AT AC INPUT BOX
DISCONNECT P5
FROMJ5

(

MEASURE LINE VOLTAGE
115 Vac or 230 Vac AT J5

CHECK THE FOLLOWING·
FOR A FAULT:
1. AC INPUT BOX
2. THERMAL SWITCH ON
TRANSFORMER ASSEMBLY
3. CONSOLE OR POWER ON SWITCH

YES

CHECK FOR FAULTY
TRANSFORMER ASSEMBLY

11-2571

Figure 4-1

H765 Fault Isolation Flowchart

4-3

Ensure the H765 is plugged in and getting primary ac power (115 Vac/230 Vac).

Check CB 1 on the ac input box.

Utilizing the flowchart (Figure 4-1) and H765 Power System schematic (Figure 3-2)/, isolate the

faulty module.

Replace the module as described in Paragraph 4.4.

When a fault is isolated to a voltage regulator, refer to Paragraphs 4.3.2 - 4.3.4 for voltage
. regulator checks'ardadjustments.
:.'

f"'

4.3.2 Voltage Regulator Checks and Adjustments
Correct power system voltages at the backplane are critical to a properly operating system. The power
system voltages are supplied by the regulatorsJisted in Table 4-2. Each voltage regulator, except the 5409730-Y A,
has an adjustment potentiometer (Figure 4-2) which is located next to the output lamp. Perform the fOIlOW(
ing steps to ensure that the voltages are within tolerance. If a voltage regulator cannot be adjusted to meet
the tolerance, check for a bad regulator,power distribution board, or wiring.

Using a DVM, measure the output voltages under normal load conditions at the backplane (Table 4-2).

Adjust voltages at the backplane to the tolerances specified in Table 4-2, as required.

Using a DVM, measure the voltage at the regulator (or power distribution board). Ensure that the
maximum voltages'at the regulator (Table 4-2) are not exceeded. These voltages represent the maxi~
mum regulator voltage prior to crowbar. (Do not adjust the regulator to these voltages.)

Using an oscilloscope, measure the peak-to-peak ripple content on all dc outputs (Table 4-2).

(
4-4

------------. .-------------

---- -

-----.--~.

_.---

------

----

-- -

--------------------~~---------~~~~~~

+5 V ADJUSTMENT

+20 V
-!;iV
ADJUSTMENT

7111-42

( .,
Figure 4-2

Regulator Adjustments

4-5

(

Table 4-2
Regulator Specifications
Voltage and Tolerance
Regulator

at Backplane

Maximum Voltage

Maximum Out-

Maximum Peak-

at Regulator (Note 1)

put Curren,t

. to"Peak Ripple

H744,

+5 Vdc± 2$O'mV

5.5Vdc

'25 A'

""'. 200mV

Ht45

-15 Vdc ±,750 rnV

, 16 vdc

lOA,

450mV

H754

+20Vdc ±l V

21.5 "dc

(Note 4)

-5Vdc ± 250 mV

:5.5Vdc,

1 - S'A (Note 3)

5409730- Y A.

+15 Vdc ±10%

Notes:L'

: : } (Not. 2)

,1.5A

Do not adjust the regu.latorto,these voltages. TheyrepresEmt the maximulTlregula'torvoltage
, prior to crowbar.

2. ''At backplane. Typical ripple ~ ±3%~,
3.

Maximum -5 V current i,s dependent upon +20 V current. It is equal to 1 A plus the current
of the +20 V supply up to a total of S A.

When adjusting the output of H754,adjust +20 Vdc first, then -5 Vdc.

(
4.3.3 Voltage Regulator Troubleshooting
The voltage regulators in the H765 Power System are designed to be replaced when a failure is detected.
However, there are unique situations when a regulator needs to be repaired in the field. Table 4-3 lists the
primary fault indications, the most probable cause, and corrective action required. This table should be
used in conjunction with the regulator's theory of operation (Chapter 3) and the print set.

Once the repairs have been accomplished or a new regulator is installed, refer to Paragraph 4.3.2 for
voltage regulator checks and adjustments.

Table 4-3
H744, H745, H754 Voltage Regulator Troubleshooting Chart
Fault Indication
No Output Voltage

Most Probable Cause

Corrective Action

1. D 1 (bottom of D 1 will appear

Replace regulator or Dl.

burnt)
2. El (DEC 723, IC voltage regulator)
4-6

Replace regulator or El (Figure 3-7).

Table 4-3 (Cont)

(

H'744, H745, H754 Voltage Regulator Troubleshooting Chart
Most Probable Cause

Corrective Action

(Cont)

3. M isadjusted output voltage

Blown fuse

1. 02 (pass transistor)

Shut power off and turn voltage adjust
fully ccw (below crowbar voltage).
Turn power on and slowly increase
voltage, per Table 4-2, until
correct value is obtained.
Replace voltage regulator or pass tran-

Fault Indication

sistor and associated components.
2. Excessive loadin9 of voltage

Replace fuse and check loads.

regulator

4.3.4 Regulator Bench Test Procedures (H'744, H745, and H754)
This paragraph suggests procedures to troubleshoot and test the H744 +5 V Regulator, H745 -5 V
Regulator, and H754 +20 V, -5 V Regulator modules. The procedures are intended to aid in locating
a fault, provided the fault has not destroyed the etched circuits.

When replacing a faulty voltage regulator, the new voltage regulator may need adjustment to compensate
for the load. If the new regulator is initially adjusted too high,:it may activate the crowbar circuit and
therefore provide no output when initially installed. If this happens, turn power off and rotate the adjustment potentiometer counterclockwise. Then reapply power (regulator should not crowbar) and adjust the regulator output.

4.3.4.1

Initial Tests - When a power system fault has been isolated to a voltage regulator (H744, H745,

or H754), examine internal fuse F 1. A blown fuse usually indicates that the main pass transistor 02 and/or
one of its drivers, 03 or 04, has short circuited. '

Check for damage to base-emitter bleeder resistors and a scorched etched board in the area of 03
(and 04 if applicable).

If the pass transistor and drivers check OK on a VOM, the fault may, be caused by continuous base
drive to the first driver, 04 (03 in H754). Check level shifter 05 for a short circuit.

4-7

Check the resistance to ground at the input to precision voltage regulator integrated circuit E 1

(

(pins 4 and 5) to determine if an external short circuit is affecting the IC.

Use the VOM to check for a short circuit between fuse terminals and ground. Possible short
circuits involving mounting TO-3 components to the heat sink may be located by connecting
VOM leads between TO-3 cases and a regulator bracket mounting screw on the end of the heat
sink.

4.3.4.2 Output Short Circuit Tests - A voltage regulator that provides no output, or low output,
without causing fuse F 1 to blow is probably working into a short-circu ited output.

NOTE
An activated crowbar or a short-circuited output in an
otherwise properly operating voltage regulator will not
cause F1 to blow.

If fuse F 1 is not blown, and

th~ area of etched circuit around the ac input to the bridge circuit

is not damaged, it is safe to apply an ac input to the voltage regulator to determine if the regulator
is overloaded by a short circuit across the output.

Connect the voltage regulator to a test bench source and advance the Variac to about 90 V (20 Vac
at voltage regulator input). If the output is near 0 V, turn the voltage adjustment fully counterclockwise and repeat the test.

If the regulator appears overloaded, check for a short circuit across the output and for a component
failure in the crowbar circuit.

4.3.4.3 Testing a "Dead" Regulator - U~e the following procedure to test a faulty regulator that does
not exhibit the symptoms described above.

Apply 115 Vac to the test bench source (25 Vac at the voltage regulator input), with no load on
the regulator output.

4-8

(

Check for 30 Vdc across filter capacitor C1 (and C2 if applicable).

Check for +15 Vdc at pin 12 of precision voltage regulator E1. No voltage at this point could
mean Zener diode 02 (H744) or 03 (H754) has failed. ,

Check for 6;8.,....7.5 Vdc at pin 6 of E1 'With respect to ground, pin 7.

If a" voltage measurements steps 2,3, and 4 are OK and there is no output voltage, pin 5 of E 1
should be positive with respect to pin 4.

E 1, pin 2, should be +0.6 V with respect to pin 3. If it is not, connect the emitter and base of 05.
If a 0.6 V indication is obtained, precision voltage regulator E 1 is OK and the fault is p~~babIY
caused by 05 or 04 (03 in H754).
4.3.4.4 Testing a Voltage Regulator After Repairs- Before returningarepaired~()'i1:age regulator to
. ~ ','

(

service, it should be checked as follows:
".-:

Connect the repaired voltage regulator to the appropriate source connector.

Set the voltage adjustment fully counterclockwise and set the load to zero.:·!·

Close the input circuit breaker and advance the Variac until output voltage is indicated (at approximately 60-80 Vac input). No audible noise should be heard under no-load conditions.

Be sure 02 is connected and soldered before loading the regulator.

Advance the Variac to 130 Vac and return to 115 Vac.

Apply a 30-50 percent load. The output voltage should remain nearly constant. A clean whistle
may be heard. A buzz or a harsh hissing sound indicates possible instability. Check waveforms as
indicated in Figure 4-3 ..

l
4-9

(
40V

30V

L---.-- 50-200,,"s_J
r--@I
FULL LOAO----"""l

Vaut

Vout _ _
NOTE 2

0---------------NOTE '1:

~O vlllt ,level shifts with AC input ,voltage.
, S"'allt20H~ jitter Is normal.

NOTE 2:' Malim"m output ripple is specified in table 4-2
Peak noise' 1-"'" mill.
"M,eqsure nQise with Ii short lOOn terl11inated piece of fall
coax, Normal 10: I 'cope probe' win no1 give 'an accllrQte
noise' mea'urement.
"-'075

(

Figure4-3 Typical Voltage Regulator Output Waveforms

7. 'Appiy 100 percent load and set the voltage adjustment for nominal output, as listed in the following chart:

H744

+5.10 Vdc

H74E)

-15.10 Vdc

H754

+25 Vdc between +20 and-5 V outputs

Apply 200 percent load and check for a decrease in the frequency and the output voltage.

NOTE

If the outputvoltage does not decrease noticeably (approximately1 V em H744, or 1 to5 V'on the H745 and
H754), do not attempt the following short circuit test.

4-10

(

Short circuit the output. The regulator should continue to operate at a low frequency with a
clean, smooth whistle and stable waveforms.

10. Increase the voltage adjustment and observe the output voltag~ when the,crowbar circuit fires.
>

•

'.'

••,'" ,

- -

•

" " ,

-"".

,:.;

• __'.

!'."'

The output voltage should be within the following ranges:
: ',:

H744

6.00-6.65 V

H745

16.8-20.5 V

H754

25.0-30.0 V and -6.0Q to --:7.00 V
;':""

4.3.4.5 5409730-YA Regulator Test Procedure-

"',".,,;

To Be Suppqed

(

'--

.• '

.,;

." •. ,,-

t. . .·

4.4 H765 POWER SYSTEM SUBASSEMBLY REMOVAL PROCEDURE

4.4.1

Introduction
"

"{'

',"

The H765 Power System access procedure enables the H765 to be acc~ssed for adjustments and subassembly removal. The removal procedures include:

H765 Power System access procedure

H744, H745, and H754 Regulator removal

AC power input box and 5409730-YA regulator removal

Fan removal

Transformer assembly removal,

Power distribution board removal.

(
4-11

---- --- -

- --

~~~~ ~~ ~-~-::c.:=_-_=~----_--

------

-----_._-----------

_ _~_~:-=-=--=--=~--=--_-_--~--_-~-=--=-~-=--=--=--=~--=--~~~=-=-~=~=-~-~-~--~~-===--~-~==~-"\'

4.4.2 H765 Power System Access Procedure (Figure 4-4)
1.

Remove ac power by disconnecting the ac Une cord from the ac power source.

Fully extend the BA 11'-Kfrom the rack, ensuring cables do not bind.

Remove the BA 11-K's top cover by removing six screWS.

Remove the cable clamps by removing four screws.

To remove the H765's top cover, loosen the top three screws and removetne back three screws,

4.4.3 H744, H745, andH754 Regulator Removal (Figure 4-5)
1.

Perform the H765 Power System access procedure (Paragraph 4.4.2).

Rotate the BA 11-K 90 degrees.

CAUTION
HoldH765 in place while. removing screws.

Tilt the H765 PQwerSystern by removing two screws on each side of the H765 (Figure 4-4).

Remove the bottom cover of theBA 11·K.

(

WARNING
Power must be removed prior to removing regulators,

Disconnect theMate-N-Lokfrom the regulator to be removed;

Remove three screws, two ~n the top and one ·on the bottom of the regulator (F igure 4~4).

Rotate the BA 11-K90 degrees to the horizontal position.

CAUTION

Use the correct length screws when installing regulator.
8.

Slide out regulator and install a new regulator.

Perform the regulator voltage adjustment procedure (Paragraph 4,3~1).

(
4-12

(

SCREW HINGE

POWER
OISTRIBUTION

BQARD
H765
POWER
SYSTEM

7111-16

Figure 4-4 H765 Power System Access

4-13

(

,': .

REGULATOR
.I\i1ATE.N~lOK,

1111-20

Figure 4-5 Regulator Removal
I

c
4·14

------=-------"------~.:--------.::---..:---

(

~---

- -

-------

4.4.4 AC Input Box and 5409730-YA Regulator Removal
1.

Perform the H765 Power System access procedure (Paragraph 4.4.2).

Rotate the BA 11-K 90 degrees.

Tilt the H765 Power System by removing the two screws on each side of the H765 (Figure 4-4).

WARNING

" , ' .~~~ut~ac .·pow~r ~i~ ~e",ot~d.,JM.?r,t((;~mQviri~the:·aC'J',
" ' : InpQfhdxpr"54Q97aO";Y,~' R~,9l1l~or~::r'
::.~

...

'" .'.~.

, :" .'

.....:,

. ~.,.' ...:.; .,:.....~;::::: . .-, .. ;'.-< ':\ .~1.~ ~··~1.:::,:, ..:. ":" .'/ ". .':
.' ".~ ,.>."'- :'.- ". ~ . . "" .' ..... :..... " ..~'.
'. '.\
........ ";-""' .. "'. i, _.... ' ;:y~'~.'
'. 4. ",,/Oisconr1~tthe~ate"Nc Loks on the top ~l1dpottorrt()f,theac.inputbox '( Figu re4~.6}.,,·
..

.(;, .•"qis~~.n~~cfi~r;~~M~~e-'N,.·L~.~st~~;'th~~4P9Z:3~YA':R~~4;I~t,oi~':'

,:.'

,;.'

,:':"'--:"0

(
'.,

:.,'

.\'..

.\.

.-'

. },:

'.,
'

; CAOTIO~

~:" . . ",'

'. When reinstalling the ac input bO;;{, ca~efuny check
cable connections. Do not connect the 4-wire, 4-pin
Mate-N-Lok connector to the flying lead 4-pin MateN-Lok.

4.4.5 Fan Removal
1.

Perform the H765 Power System access procedure (Paragraph 4A.2).

Tilt the SA 11-K 90 degrees.

Tilt the H765 Power System by removing the two screws on each side of the H765 (Figure 4-4).

WARNING
.Ensure ac power is removed prior to replacing fans.

(

CIRCUIT BREAKER

AC LINE CORD

AC INPUT BOX
MOUNTING SCREWS

AC INPUT BOX

(

. Figure 4-6 AC Input Box

4-16

Remove all modules.

On the module side of the fan, remove the two screws holding the fan (Figure 4-7).

Slide the fan out of the H765 and disconnect the jack from the fan.

4.4.6 Transformer Assembly Removal
.1.,.

WARNING·.,
Remove acpower,priQr to performing this procedure.
',."

andbot~ H744RegUla~Orsper' Paragraph 4;4.3.

RElmove the H 745, H 754,'

Remove the ae input bqx,per Paragraph' 4AA

.R~move both fans per Paragraph 4:'4.5:

Disconnect the transform~ras~mblY'~Mate-N~Loks(FigureA-8l.··

.. ~'I.,

-\7 _.'

.",

5. . Remove both screws from tbetran'sf6rme~a~sembly's cab,le clamp (Fig~re 4-9L'
6.

Rotate theBA 11~K totheihqritOntalposidon.
'.'
. " . , :.".
.

Remove the transformer. as~eJT1btY's};'ountingscrews and, nuts (Figure 4-9) a,rldHftol.J't the transformer

;

' .

assembly.

,'".'.'

WARNING
Remove ac power from the H765 Power System.
1.

Disconnect all Mate-N-Loks and the ground lead from the power distribution board.

Remove the four screws from the mountirtg bracket (F igure 4-10) and remove the power distribution
board.

(
4-17

(

BOX
FAN

FAN
JACK

BOX
FAN

(

7111 ·6

Figure 4-7 Fan Removal

4-18

(

T.IiERMAL
SWITCH·
TRA.NSFORMER
ASSEMBLY

STRIP
CLAMP

(

7111-4

Figure 4-8 Transformer Assembly

(

TRANSFORMER ASSEM6L V
MOUNTING SCREWS

Figure 4-.9 Transformer Assembly Removal (Sheet 1 of 2)

(
4-20

(

CABLE: CLAMP
MOUNTING

SCREWS

(
TRANSFORMER
A$SEM~U.. Y

TRANSFORMER
ASSEMBLY
CABLE CLAMP
7111-10

Figure 4-9 Transformer Assembly Removal (Sheet 2 of 2)

4-21

(

·.

;

MOllflltllliG

BRACKETS

7111-3

LEAP
.. :..:"
"

(
4-22

(
CHAPTER 5
UNPACKING AND INSTALLATION

5.1· INTRODUCTION
This chapter provides information on the unpacking and installation of the BA 11-K Mounting Box.
I nformationon installation certification is also included.

5;2 UNPACKING
The BA11-K is shipped ready to operate in a protective box (Figure 5-1). Remove the BA11-K from
the box and visually inspect for damage. Save the shipping cartons and packaging materials in case
it is necessary to return the BA 11-K for service. The sl ide mounts are attached to the BA 11-K, but
the mounting screws are packed in a bag placed in the shipping container.

5.3 INSTALLATION INA CABINET

(

The front of the fixed slide has an integral bracket and ismounted in the cabinet with two screws that
are secured with captive (Tinnerman) nuts. The rear of the fixed slide is attached to a separate L-s,haped
bracket with two screws and nuts. The bracket is attached to the cabinet with two screws that are se.cured with captive nuts. Mount the fixed slides equidistant from and parallel to the floor.

Lift the BA 11-K and slide it carefully into theiixed guides until the slide release engages. Unlock the
slide release and push the BA 11-K fully into the cabinet. Extend the BA 11-K enough to allow access
to the front mounting screws. Slightly loosen the front and rear slide mounting screws and slide the
computer back and forth. This allows the slides to assume a position that causes minimum binding.
Retighten the mounting screws.

5.4 AC POWER SUPPLY CONNECTION

5.4.1 Connecting to 115 Vac or 230 Vac·
The BA 11-KE/KF, designed for use on 115 Vac/230 Vac circuits, is equipped with a three-prong con-

(

nector, which, when inserted into a properly wired 115 Vac or 230 Vac outlet,grounds the chassis. It

5-1

(
SIDE PROTECTOR

~- ..

BAG

(

PROTECTOR

1'-·2569

Figure 5-1

BA 11-K Packaging

5-2

(

is unsafe to operate the BA 11-K unless the chassis is grounded, sinc~ no.rmalleakage current from the
power supply flows into metal parts of the chassis.

If the integrity of the ground circuit is questionable, the user is advised to measure the potential between
the computer case and a known ground with an ac voltmeter.

The BA 11-KE/KF operates at voltages ranging from 90 V to 132 V/180 V to 264 V (47 Hz-63 Hz), The
plug config'~'rat'ion and spe~iflcations are shown in Figure 5-2.

On installation outside of the United States or where the National Electrical Code does not govern building wiring, the user is advised to proceed with caution.

230 V
MALE PLUG
(SliIIGLE PHASE)

_:.------,;'--- GROUN.D
NEUTRAL
OR RETURN

CONNECTOR

DESCRIPTION

SPECIFICATIONS

NEMA*
POLES WIRES
CONF!GURATION

PLUG
DEC 'PART NO.

RECEPTACLE

DEC PART' NO~ .

115V,15 AMP

5-15

90-08938

12-·05351

230V,15 AMP

6-15

90-08853

12-11204

* ADD P SU FFIX FOR PLUG
ADD R SUFFIX FOR

RECEPTACLE

11-2572

Figure 5-2 Connector Specifications

5.4.2 Quality of AC Power Source
If the BA 11-K is to be installed in an electrically noisy environment, it may be necessary to condition
the ac power line. DEC Field Service engineers can assist customers in determining if their ac line is
satisfactory.
5-3

~~~--.----~--

~--:-

---~_-

-_---::-___

-_~_-_--_----_~--_-~__:-_:---_----

-:-~'~_-.--_-

-::- __ - _ - - - - -,---_ - - -

-_. --_-----:c--:--:_--

--~-_-_._:_:_:_:-_o_---

-- " - " - - - - - " -

5.5' REMOTE POWER CONTROL

Power control (Figure 5-3) of the BA 11·K can be accomplished by the following three methods;

A key switch can be utilized to control the BA1 1-1<. This is accomplished by connecting the
proper cable to J2 or J3 on the aC input box.

Mate-N-Loks J1, J2, or J3 on theac input box can be configured to enable a power controller
to control application of ac power.

CB 1 on theac input box can be used as anon/off switch.

5.6 INSTALLATION CERTIFICATION

Once the BA 11-K has been installed,it is strongly recommended that a system diagnostic be run to
ensure thatthe equipment operates corr.ectly and that Installation has been properly performed. Because system configurations vary wi~ely, no one diagnostic will completely exercise all the attached

(

devices.

The user's manual that comes with the diagnostic package should be consulted for the appropriate
diagnostic to be run. The user's manual lists the devices that each diagnostic will exercise. Once the
diagnostic is selected, the respective diagnostic write-up should be consulted for specific operating
instructions. if the user is not familiar with console operation and/or procedures for loading paper
tapes, he or she should read the applicable manual.

5-4

;.,

(

lr--

TO OR FROM
EXTERNAL
POWER CONTROL
, -3 ON
, -3 OFF

2
.1--

BAII-KE,KF
MOUNTING BOX

1
-

AC INPUT BOX

~
I

2
3

CONSOLE
POWER
SWITCH
, -3 ON
2-3 OFF

~
o

2
o

r-!TO POWER ~
CONT~~LLER ~-H-AC

OUTLET

-l/-----'
11-2563

(

Figure 5-3 Power Control

5-5

BAII-K MOUNTING BOX
MANUAL
DEC-II-HBKEF-A-D

I
I

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