Seagate ST-506 Service Manual

SEAGATE

ThCHNOLOGY

ST-506

SERVICE

MICROWINCHESfER

MANUAL

MAY

1,

1982

360

El

Pueblo

Road

Scotts

Valley,

CA

95066

Phone(408)438-6550

SEO]CN

1.0

I~~Irn

1.1

1.2

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

General

Description

Specification

1.2

•1 Phy

Sunnary

sical••

TABLE

CF

<XNIENTS

•••••••••••••••••••••••

••••••••••••••••••••••••••••••••••••

"" """ e e e

~

••••••••••••••

'"..'" '"..'" '" '"

••

1

2

2.0

~y

2.1

2.2

1.2.2

1.2

1.2.4

G'

General

2.1.1 .1.2

2

2.1.3

2.1.4

2.1.5

Reliability

•3

Per Functional

CPERA.TICN'S

•...•..••.•.•.••••...•.•......••...•...•.••.••.•.•

Recording Tr

Winchester

Discs

Air

Mechanical

2.1.1

Track~Sensor

f ormance

ack

Format

Filtration

Theory

•••••••••••••••••••••••••••••••••••••••

•••••••••••••••••••••••••••••••••.•••••••

••••••••••••••••••••••••••••••••••••••••••

Format

••••••••••••••••••••••••••••••••••

•••••••••••••••••••••••••••••••

Heads

••••••••••••••••••••••••••••••••••

Systern

•••••••••••••••••••••••••••••

••••••••••••••••••••••••••••••••••••••••

•••••••••••••••••••••••••••••••••••.•

"

••••••

2

3

4

4 4 6

6

6 7 7

2.3

2.2.2

2.2.3

2.2.4

Electrical

2.3.1

2.3.2

2.3.3

Motor Speed Auto Drive

Index Ground

Spindle

Sensor

Spr

Brake

Theory/Flowchart

Recalibration

Selection

••••••••••••••••••••••••••••••••••••••

ing

•••••••••••••••••••••••••••••••••••••

.......•....•.......................•

••••••••••••••••••••••••••••••

Control

•••••••••••••••••••••••••••••••

•••••••.••••••••••••••••••••••••••

7 7

8

9

9 11 13

SEO]CN

TABLE

CE

a:NIENTS

2.3.4

2.3.5

2.3.6

2.4

Test

2 • 5 Schana

3.

0

~I~<:E/REI>AIR

3.1

Introduction

3.2

Rexnovals

3.2.1

3.2.2

3.2.3

Step

(peration

Read

Cperation

Write

Point

tic

Cperation

Description

s••• •• ••• •• ••• • •• •• • •• • ••• •• • •• • •• ••• • •• • •• • •• •28

•••••••••••••••••••••••••••••••••••••••••••

•••••••••••••••••••••••••••••••••••

••••••••••••••••••••••••••••••••••

•••••••••••••••••••

,

••••••••••••••

••••••••••••••••••••••••••••••••••••••••••••

And

Main Motor

Spindle

Adjusttnents

Control

Brake

••••••••••••••••••••••••••••••••

P.C.B

•••••••••••••••••••••••••••••••

P.C.B

••••••••••••••••••••••••••••••

••••••••••••••••••••••••••••••••••••

14 17

19

22

34

35

36

4.0

3.2.4

3.2.5

3.2.6

3.2•7 Front Cover

3.2.8

3.2.9

ILLUSTRATED

4.1

Physical

4.1.1

4.1.2

4.2

Carr~onent

Index

Ground

Sensor

Spring

Track~Sensor

•••••••••••••••••••••••••••••••••••••• Front Side

PARTS

Drive

Connectors

Cover

Franles

CATALOG

Locations

Exploded

LED

••••••••••••••••••••••••••••••••••••••

Exploded View

Locations

•••••••••••••••••••••••••••••••••••••

••••••••••••••••••••••••••••••••••••

•••••••••••••••••••••••••••••••••••

••••••••••••••••••••••••••••••••••

••••••••••••••••••••••••••••••••••••

View

••••••••••••••••••••••••••••••

•••••••••••••••••••••••••

•••••••••••••••••••••••••••••••••••••

36

37

38

40

41 42

43

ii

SEO]CN

TABLE

OF

c:INIFNrS

4.2.1

4.2.2

4.2.3

4.3.1

4.3.2

4.3.3

4.3.4

Main Main Motor

Spare

COntrol COntrol

Control

Control Control

Control

Parts

p.e.B.

P.C.B.

P

.C.B.

P

.C.B.

P

.C.B.

List

PfiN

20019

20040

P/;N

20003

PjN

20019 20040

20003

••••••••••••••.•••••••••.••••••••

•••••••••••••••••••

••••••••••••••••••

•••••••••••••••••••

••••••••••••••••••

44 45 46

48 50 52

53

iii

FIGlRE

2.1

Tt

ack

Format

LIST

CF ILllSTRATICNS

••••••••••••••••••••••••••••

~

•••••••••••••••••••••

5

2.2

2.3

2.4

2.5

2.6

2.7

2.8

2.9

Test

Point

TestPoint

1 Tim.ing

2

Tilning

4

Tim.ing

5

Tilning

and

7

11 and

Layout

•••••••••••••••••

"-

•••.•••

eo

••••••

••••••••••••••••••••••••••••••••••••••••••

8

Tim.ing

13

p.e.B.

- P

••••••••••••••••••••••••••••

Tilning

.C.B.

••••••••••••••••••••••••••••••••••

P~

20019

20040

LIST CF

TABLES

••••••••••••••••••••••••

~

••••••••

'

•••••

•••

••

24

25

26

27

TABLE

2.1

Step

Pulse

Encoding/Phase

Sequencing

iv

•••••••••••••••••••••••••

~

16

Introduction

1.0

INTRODUcnON

1.1

General

Description

ST-506

Service

Manual

The

ST-506

non-fcmovable

emplQYs formatted sectors

may

Low actuator

simplicity

be

cost

one

capacity

per

daisy

and

of

maintenance

electronic

Mechanical

are

provided

PCB's

and

recirculating

second ambient

aSSUf

the

motor

rise and

power

port

air

es

adequate

head

assemblies

within

the

up

and

ability

with.nothermal

disc

5

i/4

moveable

track,

chain

unit

open

m.echanical

free

are

contamination

by

an

system

in

the

without

air flow and

disc

the

enclosure,

to

drive

is

inch

head

of

the

256

bytes

connected

reliability

loop

stepper

operation

mounted

impact

supplies

filter

chance

area.

from

Therm.al

the

providing

immediately

a

random

discs

four

in

to

he

per

as

service

ads

sector,

one

are

head

construction

throughout

outside

protection

resistant

clean

air

assembly

of

contamination.

uniform

isolation

disc

enclosure

significantly

perform

stabilization

access

storage

153

and

surfaces

612

system.

achieved

positioning

and

the

HDA

for

aluminum

through

allows

temperature

read

delay.

storage

media.

data

Each

tracks.

is

tracks).

through

mechanism.

electronic

life

of

for

field

the

heads,

enclosure.

a

0.3

pressure

A

patented

distribution

of

the

stepper

yieldsavery

greater

and

write

device

with

disc

The

5

meg

abyt

Up

to

four

the

use

ofaband

The

controls

the

drive.

serviceability.

actuator

A

self

micron

filter.

equalization

spindle

throughout

and

low

temperature

off-tr

ack

operations

two

surface

total

es

(32

drives

inherent

allows

Both

and

discs

contained

with

pump

spindle

margin

after

A

The

ST-506

SA1000

electrical

family areidenticalto same

DC

voltage

of8inch

the

industry

and

connector.

interface

fixed

standard

disc

is

drives.

No

similar

The

minifloppy

AC

power

to

ST-506

is

the

Shugart

disc

drives

required.

size

Associates

and

mounting

and

uses

the

Seagate

Technology

PAGE 1

5/1/82

Introduction

1.2

Specification

Summary

Sf-506

Service

Manual

1.2.1

Physical Environmental Ambient

Temperature

ReIative

Maximunelevat

Shock:

D.C.

Specifications

Lnnits

Temperature:

Ci>erating Non-operating

Gradient: Operating Non-operating

HlIl1idi

ion:

Operating Non-operating

<»erating

r-~on-opelati.ng

Power

+12V +5V

Maximun

Requiranents: ±5%, ±5%"

Ripple

=

ty

=

:::

1.8A

Typical,4.5A

.7A

Typical,

=

400to

-400to

'180F / Hour (100C)

Below

8

to

10,000

-1000

,lOG's

50mv

1220F

1400F

condensation

80%

Non-condensing

Feet

to

30,000

(On

side

At power on

1.0A

Maximum

peak

to

(40to

(-400to

Feet

frames)

peak

(12V,

500C)

600C)

5V)

Seagate

1.2.2

Technology

Mechanical

Height Width Depth '¥eight

Shipping

Heat

Dissipation:

Typical

Maxinulm =

Reliability

NITBF

MI1R =

P,M:

= Not

Component

Dimens

=

ions:

=

Vleight =

=

Specifications

=

design

PAGE 2

3.25

29

life

Inches

5.75

Inches

8.00

Inches

4.6

Pounds (2.1Kg)

7.0

Pounds (3.2Kg)

25

Watts Watts

11,000

30

= 5

Minutes

required

Years'

PCH,

Typical

usage

5/1/82

Introduction

Sf-506

Service

Manual

1.2.3

Error

Perfonnance Capaci

Rates:

Soft

Hard

Seek *Not

ty

Unformat

Formatted:

Read

Errors

Read

Errors*

Error

Per Per Per

Per Per Per Per Sectors

s =

recoverable

Specifications

ted:

Drive

Surface

Track

Drive

Surface

Track

Sector

per

within

=

Track

=

1

16

per per per

retries

6.38

1 •59

10416

5

.0

1.25 8192

256

32

10

bits

12

10

bits

6

10

seeks

Megabytes Meg

aby t es

Bytes

Meg

aby t es

Megabytes

Bytes

read read

1.2.4

Access Time:

Track Avera.ge* =

lv1ax

imum

Settling

*Reducible

*Reducible Transfer Average Functional Rotational

Recording Flux Track Cyl

iode!

Tracks ReadfWrite

Di

scs

Rate:.

Latency:

Density

Densi

Density

s =

=

to

Track

=

** =

Time =

to

85

to

205

Specifications: Speed

=

ty

=

Heads =

3

milliseconds

170 500

15

milliseconds

IDS

using

IDS

using

3600

7690 BPI Maximum 7690

255 153

612

4 2

TIl

RPM

FeI

fast

5.0

8.33

±1%

1vlax

milliseconds milliseconds

seek

algorithm

seek

algorithm

Megabits

milliseconds

imum

per

typical

second

Seagate

Technology

PAGE 3

5/1/82

Theory

2.0

of

Oper

THEORY

2.1

General

ations

OF

OPERATIONS

ST-506

ServiceManual

2.1.1

The method

encoding data both

the

Due precompensatiori. insure precompensation pattern

amount bits.

2.1.2

The

modified format ST-506 contain

Recording

ST-506

implemented

scheme

bits.

the

preceding

beginning

to

predictable

data

determines

of

this

All

other

Track

track

version

is

common

drives

the

uses

Clock

integrity

Format

format

bit

Format

modified

to

record

increases

bits

are

written

and

the

of

the

bit

cell,

bit-shift-

This

function

at

of

write

which

precompensation

data

used

of

are

formatted

pattern

patterns

the

to

many

UJL

data

bits

on

IBM

frequency

data

disc

data

current

while

the

specified

on

must

is

are

the

System

industry

at

the

Refer

on

capacity

only

when

bit

data

phenomena,

must

be

cylinders

be

precompensated.

12ns

written

Seagate

factory

to

34 standard

modulation

the

drive.

by

data

cell.

bi~s

are

provided

error

128

for

both

on

time.

ST-506

double

before

Figure-2.1

(MFM)

replacing

bits

Clock

written

write

by

rate.

through

early

disc

density

floppy

shipping.

(Track

as

This

double-density

clock

are

notpres

bits

in

data

the

The

Sf-506

152.

The

and

drive

format.

disc

Format).

the

encoding

bits

ent

are

written

the

middle.

may

require

controller

requires

The

recommended

late

written

isaslightly

drives.

Data

fields

with

in at

to

data

This

All

The

Seagate each of identification field m

It

not format

Seagate

evaluation. 3%. specified

containing

which

ark

should

required.

The

contains

and

is

format

ST-506 environmental

8192

error

be

an

The

soft-sector

256

bytes

field

that cylinder, checking

noted

Use

integral

that

of

uses

format

specification

format

of

are

is

different

head,

polynomials.

the

any

other

part

of

Cyclic

also

and

power

divides

data.

data."

format

the

Redundancy

allows

for

Total

than

and

format

drives'

foraplus

spindle

limits.

Each

any

sector

used

requires

performance

speed

each track

by

track

capacity

sector

other

information

Seagate

careful

Checking

or minus

variation

into

is

identified

on

the

as

is

recommended

evaluation,

and

(eRC)

speed

32

sectors

is

10416

drive. well

operation.

for

variation

is

1%

as

over

with

bytes,

by

The

address

and

as

the

The

error

the

an

ID

of

Seag

ate

Technology

PAGE 4

5/1/82

FIGURIE

20

-0

l>

C)

m

c.n

INDEX

~

WRITE UPDATE

----fl

I

I I

I

Gap 1

16X

SYNC

4E

13XOOA11

~

lOAM

FE

ID

Field

eSC

IrI

~I~I~I~

TRACK

~

Repeated32,times

--

- Gap

C

3xOO

FORMAl·

(314

2-

----

113xoo A11F81

J

'--r

Data

AM

AS

SHIPPED

Bytes)

Data

Fie~d

256

Data

I

GaIP

~I~

C C

3XOO

,

__

3

f15X4E

Gap4

352X

4E

Nominal

rL

__

lL--' _

NOTES:

1. Nominal Track Capacity =

2. Total Data

3. Sector interleave factor is4.SequE!ntiallD Fieldsare sector numbered0,B, 16,24,

4. Data Fields contain CRC

5.

6.

Bit7of Bit5of

7.

8.

Bit6of

Bytes/Track=256

1,9,17,25,2,

the

Fire Code

Head Byte ID Field equals 1 in a defective sector (Cylinder 0 is

Head Byte reserved Head Byte reserved

=X16+X12+X5+1

10,

bit

10416

x

18,

pattern

for for

Bytes .

3~~

=

8,192

26,

...

etc.

0000

nl.lmberingcylinders nl.lmbering cylinders greater

as shipped

greate,"

than than

256 512

orror

free)

Theory

of

Operations

ST-506

Service

Manual

2.1.3

The

technology. contact radial supported

The

grams. operating

cylinder height micrcinches.

The

orientations Winchester head/£lexture

resistive

2.1.4

The discs oxide by

40 diameter.

Winchester

Seagate

start-stop

track

on

Winchester

This

conditions.

is

of

load

force

to

Discs

ST-506

as

the

technology.

130mm

microinches

Technology

The

density

an

heads is

19

microinches

the

heads

of

the

heads

assembly

head

disc

recording

outside

Heads

head/flexture

operation.

is

~1r

bearing

used

the

typical

Tne

at

of

9.5

grams

disc

drive

to

incorporates

and/or

drive

media.

The

diameter.

increasing

ST-506

(supporting

Bit

255

TPI.

creat~d

are

loaded

value

flying

withatolerance

the

any

media

uses

actual

linearly

height

outermost

is

sufficient

will

not

significant

an

damage

two

non-removable

The

discs

disc

Thickness

from

uses

The

by

conventional

arm)

packing

heads,

the

toward

to

allow

of

cylinder

enough

affect

extremely

when

are

dimensions

of

the

assembly

density

rotating

required

the

of

±3

the

degree.

shipping.

designed

magnetic

inside

Winchester

is

designed

is

7690 BPI and

when

the

heads

microincheseThe

so

low

are40mm

operational,

disc.

disc

at

is

24

that

flying

Additionally,

mass

double

upon

coating

diameter

surface

stability

the

microinches,

various

height

design

sided51/4

curr

inside

to

head

at

in

innermost

flying

mounting

of

that

ent diameter

is

20

the

outside

for the

are

9.5 all

±3

the the

is

inch iron

to

Seag

ate

Teclmology

The

disc

thickness.

The

disc

minimum

expectancy

2.1.5

All filtration

the functions. seal

auxilIary normal

the

Air

drives

life

ed

He

outside

surface

This

lubricant

of

10,000

of5years.

Filtration

manufactured

system.

of

the

First,

ad/D

isc

port

operation

allows

environm

is

value

start/stop

No

drive.

the

Assembly

there

coated

is

equivalent

has

sufficient

System

by

Sea&-ate

maintenance

The

filter

pressure

is

ent.

withaTeflon

to

abrasion

cycles.

Technology

or

adj.ustments

integral

maintains

throughout

equalization

no

measurable

PAGE 6

lubricant

a

uniform

The

0.3 Class

the

air

resistance

magnetic

incorporate

micron

100

IiIe

of

with

flow

40

to

60

monomolecular

to

discs

an

are

needed

air

filter

standards

the

drive.

ambient

between

angstroms

withstand

have

integral throughout

performs

inside

Second, air. the

During

HDA

film.

a

life

air

two the

an

and

5/1/82

in

a

Theory

of

2.2

Op

er

ations

Mechar..ical

ST-506

Service

Manual

2.2.1

The Winchester

the routine. by fJ/Phase

The light-emitting-diode heads

stepper components

as

2.2.2

The to

the width.

The

transducer

preamplifier.

the

TracktJSensor

Track

internal

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the

controller.

"A".

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are

positioned

motor

long

as

the

Index

the

Index

drive

sensor

interface

sensor

DC

~

optical heads drive

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shaft

of

light

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sensor

type.

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returns

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control

~

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mechanically

the

sensor.

beam

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of

the

outputs

used

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case

to

interrupter

positioned

electronics

signal

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at

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cylinder

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remains

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sensor

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output

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power-on

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interfaceis

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interrupter

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to

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beam

outputavalid

the

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electrically

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attached

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microseconds

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reluctance a

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by

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ms),

in

ties

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ate

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hub

ferrous

the

spindle

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set

to

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hub

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of

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composition

motor

sensor,

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dimension

30 mils

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incorporates

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drive

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inducing

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factory.

a

grounding

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electrical

PAGE 7

two

metal

is

non-magnetic.

tab

to

the

pulse

spindle

contact

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pass

output.

motor

spring

charges

tabs

attached;

within

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close

and

revolution

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spindle

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spindle

one

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sensor

motor

task

motor

5/1/82

of

a

of

Theory

of

Oper

ations

ST-506

Service

Manual

2.2.4 The

when

the engages

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(.0

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material

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of

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dimension

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spindle directly

with

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set

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draw

contact

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at

10 mils

motor

from

brake

life

a

Seagate

Technology

PAGE 8

5/1/82

Theory

of

2.3

Operations

Electrical

Theory/Flowchart

ST-S06

Service

Manual

~L

SFNSCB

2.3.1

Block

Motor

Diagram-

Speed

Control

I I I

CI:MPARAKR

FunctionalDescription-

Initially,

effect

physical

allowing

level Al

the

that

will

level

transistor

be

H

I

when

position

CS

to

travels

off

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SfAR1ER

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power

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charge

through

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up.

effect

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first

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current

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,

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high

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level

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1

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stationary

level,

into

will

A2

depending

keep

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SPINJLE

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output

high.

coil

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the

on

turned

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selected

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the off,

a

low

result,

by

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ate

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As

the

responsible

controlling

to

coils

A

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4

on Integrator

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1) speed

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Ql

volts

pin7of

sequence

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error

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speed

low

pulse

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for

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andB

on

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and

force

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allow

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up,

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between

off

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current

relays

to

the

speed

PAGE

the

device

long

6

the

pin1of

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motor

applied.

senses

high

enough

volt

output

to

is

as follows:

speed

current

error.

9

effect

coil

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the

going

for

A2

low.

enter

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to

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CS

to

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generates

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motor

position

slow

receive

supplied

physical

of

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charge

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direct

coils.

information

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to

pulse

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wave

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to

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5/1/82

and

turn

7

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ations

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7

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during

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for

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AI.

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with error

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ST-506

circuit

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information

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amount

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which

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to

control

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current

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the

for

Seagate

Technology

PAGE 10

5/1/82

Theory

of

Operations

ST-506

Servic

e Manual

I

~

2.3.2

Block

AutoRecalibration

Diagram-

512PlLSE

aINIER

lP

10

SPEID

RECAL

PULSE

TRACK

ZERO

DRIVE

READY

~AIJ---------------------.;_......J

FunctionalDescription-

Upon and

read,

power-on,

active

initial

recalibration

Track

power

write,

Ready

~.

application,

latch

or

isacombination

seek

are

all

operations,

the

reset.

of

up-to-speed

Before it

must

the

drive

counter,

the

drive

first

being

up-to-speed

can

perform

become

up-to-speed

Ready.

latch,

and

any

At

an

As

the

drive supplied counter of

3600

clocks

power-on,

the

will

the

half

will

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high.

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as

up-to-speed

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to reaches

revolutions

the

heads

increment

phase

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reset

the

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its

line

a

step

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it

are encoder

to

heads

pulse.

begins

the

index

512,

up-to-speed

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not

the

closer

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to

Phase

high

and

latch,

15

to

spin,

counter

the

drive

per

minute.

latch.

force

the

positioned

up/down

will

to

select

Track~.

"A".

reach

block

milliseconds

Track

condition,

any

The

recalibration

will

provide

signal

to

direction

counter.

go

an

once

is

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over a

~,

the

future

later,

true.

index

assumed

stepper

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since

the

recalibration

index

the

pulse

each

output

the

of

the

Track

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each phase

the

at

recalibration

pulses

latch,

Ready

seek

from

revolution.

to

be

rotating

from

recalibration

stepper

~,

heads

power-on

the

each

increment

that

are

latch

from

in

conjunction

signal

complete

to

the

Index

When

at

up-to-speed

latch

motor

successive

of

moves

behind

the

latch

being

the

the Track

up down

will

gated

drive

timer

sensor

the

its

full

counter

was

reset

outward.

index

the

counter,

heads

~,

counter

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clocked

release

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will

is

index

speed

at If

pulse

one

they

the

cause

Seag

ate

Teclmology

PAGE11

5/1/82

Theory

of

Operations

The normal will normal.

active

operations

stay

If

set

state

until

this

of

Seek

can

power

occurs,

Complete

begin.

is

interrupted

the

recalibration

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is

a

signal

up-to-speed

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drops

sequen.ce

ST-506

to

the

and

recalibration

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will

Service

controller

than

again

20%

be

initiated.

Manual

that

latches

below

Seag

ate

Technology

PAGE 12

5/1/82

Theory

of

Oper

ations

ST-506

Service

Manual

I

DRIVE DRIVE DRIVE

DRIVE

2.3.3

Block

SELECf 1 SELECT SELECf 3

SELECf

Functlonal

Drive interface.

Drive

Diagram-

2

4

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Select

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to

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I

Seagate

Technology

PAGE 13

5/1/82

Seagate ST-506 Service Manual

Specifications and Main Features

Frequently Asked Questions

User Manual