Operating instructions

ManualsBrandsMilwaukee ManualsDo-It-Yourself tools6184-01

pulse

at

U220

pin

17

from

falling

low

until

the

timing

capacitors

have

discharged

.

Transistors

Q212

and

Q214

and

front-panel

HOLD

OFF

control

R210

provide

variable

current

to

the

timing

components

to

change

the

hold-off

time

period

.

LOCKOUT

BUFFER

AMPLIFIER

A

Sweep

Lockout

pulse

(high)

may

be

initiated

at

interface

connector

pin

B8

by

mainframe

switching

functions

.

A

high

level,

coupled

from

interface

connector

B8

through

the

Lockout

Buffer

Amplifier

Q202

and

Q206

to

the Lockout

input

at

U220

pin

18,

initiates

a

Swp

Disable

pulse

at

U220

pin 17,

thereby

disabling

the

sweep

.

The

Lockout

pulse

(high)

is

also

applied

through

Q358

(diagram

4)

to

the

hold

off

start

input

at

U220

pin

16

to

enable

the

hold

off

cycle

.

HOLD

OFF

OUTPUT

AMPLIFIER

The

Hold

Off

Output

Amplifier

inverts

and

amplifies

the

Hold

Off

signal

from

U220

for

the

mainframe

.

Transistor

0272

inverts

the Hold

Off

signal

from

U220

to

provide

a

high

level

when

hold

off

is

present

.

The

inverted

signal

is

coupled through

emitter

follower

0274

to

interface

connector

B4

.

AQ

C

5645

AQR



-

.

.

.m

._



I

NH

s~

Figure

3-4

.

Detailed

block

diagram

of

Logic

circuit

.

Theory

of

Operation---7B87

SWEEP

GENERATOR

The

Sweep

Generator

produces

a

linear

rampwaveform

for

the

mainframe

when

gated by the

Trigger

Generator

.

The

sweep

trace

is

displayed

either

independently

or as

the

intensified

sweep

(when

used

with a

companion

delayed

time

base

unit)

of

an

alternate

display

.

The

sweep

ramp

is

also

used

as a

time

reference

for

the

delay

pickoff

comparator

(diagram

5)

.

A

sweep

gate

(unblanking)

is

also

generated

in

this

circuit

block

.

The

linear

sweep

ramp

waveform

is

produced

by

charging a

capacitor

from

a

constant-current

source

.

The

slope

of

the

ramp

determines

the

sweep

rate

of

the

displayed

trace

.

Figure

3-5

is

a

block

diagram

of

the

Sweep

Generator

.

TIMING

CURRENT

SOURCE

The

Timing

Current

Source

stages

generate

a constant

current

for

the

Ramp

Generator

stages

(see

Figure

3-5)

.

DELAY

GATE

INHIBIT

DIAG

DELAY

MODE

-

-'---~

R2

CONTROL

OUT

DIAG

01961-4

3-7