BRUEL & KJAER 1022 - Power Supply

BRUEL & KJAER 1022

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[n

addition

to

th

e

volt

calibration

on

the

switch

ATTENUATOR

OUTPUT

there

is a1so a

dB

calibration,

and

the

calibration

is,

as

mentioned

above,

given

in

dB

re.

1

volt.

An

example

will

explain

the

use

of

the

dB

scale:

If

the

OUTPUT

LEVEL

is

adjusted

in

such

a

way,

that

20 dB is

read

on

the

meter

scale,

and

the

s

witch

ATTENUATOR

OUTPUT

is

in

the

position

-

30

dB

th

en

the

signal

level

at

the

output

soc

ket

will

be

20

-3

0 = - 10

dB

re. 1

volt

( o.316 V).

The

signal-to-noise

ratio

of

the

Oscillator

is

greater

than

70

dB

for

maximum

output

voltage.

It

is

independent

of

the

position

of

the

attenuator,

but

some-

what

dependent

on

the

position

of

the

potentiolffieter

marked

OUTPUT

LEVEL.

The

best

result

is

obtained

when

the

voltmeter

has

a

deflection

around

20 dB.

Harmonic

distortion

is

dependent

on

the

setting

of

the

OUTPUT

LEVEL

potentiometer.

As

long

as

the

output

is

kept

within

the

meter

range,

the

distortion

will

be

of

the

order

indicated

in

Fig.

1.3.

Power

Supply.

The

Oscillator

can

be

operated

from

a 240, 220, 150, 127, 115

or

100

volts

AC

power

line,

the

power

consumption

being

about

60

watt

s.

The

proper

voltage

is

selectable

by

a

switch-fuse

combination

situated

at

the

rear

of

the

instrument.

To

select

the

voltage

it

is

necessary

to

remove

the

fuse

by

turning

the

hexagonal

disc

head

in

the

centre

of

th

e

sw

itch

anti-

clockwise.

Then

turn

the

head

of

the

voltage

adjuster

with

a

co

in

until

the

white

mark

is

aligned

with

the

required

voltage.

The

fus

e is

th

en

replaced.

It

should

be

noted

that

if

the

aparatus

is to

be

operated

from

a DC

power

line,

or

from

an

accumulator,

a

vibrator

unit

or

a

rotary

converter

is

required.

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