Racal Instruments 9916 User Manual

Racal Instruments 9916

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NOTE:

Ripple Level

There

are

no

adjustments

in

the

power

supply

circuit.

If

the

5V

supplies

are

outside

the

limits

given

above,

the

supply

voltage,

the

transformer

primary

connections

and

the

setting

of

S52

should

be

carefully

checked.

If

these

are

correct

the

zener

reference

diode

D30

should

be

checked.

5.7

Connect

the

variac

(Table

3,

item 9)

to

the

local

a.

c.

supply,

and

power

the

unit

under

test

(UUT) from

the

variac.

Monitor

the

variac

output

with

the

multimeter

(Table

3,

item

1),

and

adjust

to

give

the

minimum

voltage

of

the

range

which

suits

the

local

supply.

5.8

Using

the

oscilloscope

(Table

3,

item

2)

monitor

TP4and

TP6

using

a.c.

coupling.

The

power

supply

100Hz

ripple

should

be

less

than

150mV

peak

to

peak.

BA

TTERY

POWER

SUPP

LIES

CHECK

Charging

Rate

Checks

5.9

The

chargi

ng

rate

can

be

checked

only

when

the

battery

pack

is

fitted.

It

can

be

checked

by

inserting

a

multimeter,

set

to

an

appropriate

current

range,

in

series

with

the

battery

lead,

or

by

measuring

the

volt

drop

across

a

charge

path

resistor

and

calculating

the

current.

The

latter

method

is

recommended.

Measurement

is

made

with

a.c.

supplies

connected

and

the

POWER

switch

ON.

WARNING:

LETHAL

VOLTAGES

ARE

EXPOSED

are:

5.10

For

the

A

Battery,

(+

5

volts),

voltage

measurement

should

be

made

across

the

3.90

resistor

R128. This

is

accessible

from

the

top

of

the

main

p.

c.

b.

5.11

For

the

B

Battery,

(-

5

volts),

voltage

measurement

should

be

made

across

the

39D

resistor

R138. This

measurement

can

also

be

made

from

the

top

of

the

main

p

.c.b

..

5.12

Measurements

should

be

made

across

both

resistors

with

the

rear

panel

switch

In

both

the

LINE POWER

and

CHARGE

positions

to

allow

calculation

of

the

trickle

charge

and

full

charge

rates

respectively.

The

charging

current

varies

considerably

according

to

the

state

of

charge.

Nominal

values

during

the

middle

of

the

charge

period

~

5-5

9916

Vol.2.

Table of Contents

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Racal Instruments 9916 Specifications

General

Brand	Racal Instruments
Model	9916
Category	Measuring Instruments
Language	English