Solartron 7151 Service Manual

7151

COMPUTING MULTIMETER

MAINTENANCE MANUAL

Issue 1: June 1984

SOLARTRON

Schlumberger

Solartron pursues a policy of continuous development and product improvement
The specification in this document may therefore be changed without notice

Solartron Instruments, Victoria Road, Farn bo rough
Hampshire, England GU14 7PW Telephone: Farnborough [phone]
Telex: 858245 Solfar G Cables: Solartron Famborough
A division of Schlumberger Electronics (UK) Ltd

PartNo. 71510011

19©84

n

7151 COMPUTING MULTIMETER

MAINTENANCE MANUAL

1642g/0072g

CONTENTS

Chapter 1

Chapter 2

Chapter 3

Chapter 4

Chapter 5

Chapter 6

General

Calibration Procedures

Dismantling & Reassembly

Circuit Descriptions & Diagrams

Fault Diagnosis Guide

Parts Lists &

Component Layout

1642g/0072g

r

Chapter 1 General

1642g/0072g

f

CHAPTER 1

1. GENERAL

The Solartron 7151 Computing Multimeter performs all common

functions, and offers: a library of

measurements;

The instrument is suitable for general purpose bench work, or for use
within a system where 7151 would
control interfaces. The interfaces provided are the IEEE 488 (1978) STD
system and the RS232C V24 serial system.

2. SAFETY

The 7151 multimeter has been designed in accordance with the

recommendations of IEC 348. To ensure the user's safety, and the
continued safe operation of the instrument, it is advisable to fully
observe the procedures and specifications given in the Operating Manual

(Part No. 71510010).

An Earth wire is provided to ensure the user's safety. Therefore, if an
extension mains cable is used, check that the Earth connection is
maintained throughout the length of the extension.

When using 7151 on

(e.g. inductive circuitry giving high back emf's such as

a large mains transformer), it is most important that 7151's test leads
are disconnected from the equipment before

that harmful back-emf's do not reach 7151. Care should

exercised when handling the input leads, especially where
are known to be present, or where

and a programmable power-on status.

equipment which is capable

programs;

be operated via

high transients could

clock controlled

one of

of delivering

switched it off. This ensures

measurement

its remote

high voltages

the secondary

always be

high

occur.

voltages

of

Whenever it is likely that the safety of the instrument has been impaired

- e.g. if it shows visible signs of damage, if it fails to perform
correctly, or if the specifications have been exceeded in any way - it
should be made inoperative and referred to a suitable repair depot. Any
maintenance, adjustment or repair of the multimeter must be carried out
by

skilled personnel only, in accordance with the procedures and

precautions detailed in this Maintenance Manual (part no. 71510011).

A

Wherever this symbol appears on the front or rear panel it is
advisable to consult the appropriate section of
further information.

3. SUMMARY OF OPERATION

A schematic block diagram of the 7151 is shown in Fig. 1.1. 7151 is

essentially a
technique of analog to digital conversion.

All inputs to the instrument are first converted to dc voltages before
being passed to the input amplifier. This is simple enough for current

(dc) and resistance, but ac inputs also undergo rms conversion to dc.

All inputs are suitably scaled by the input amplifier and passed to the

voltage measuring instrument which uses the pulse width

the Operating Manual for

0072g/1634g

1.1

analog to digital converter (ADC). With no input,
balanced pulse trains of

received, the

opposite

then

manner, proportional to the size of the input. These trains are

converted to a single end and gated into a reversible counter. The

mark-space ratios of the trains respond in an

mark space ratio 1:1. When an input is

the

ADC produces two

equal and

nett result is a pulse count proportional to the measure of the input.

The measuring circuits are controlled by what is termed the 'floating'

logic and

'Piggyback' ROM. The other circuits of 7151 are organised in a
arrangement which is controlled by the 'earthy' logic and consists
essentially

between the floating and earthy logic is acheived by

links. It is the

of

measurements, processing, remote

displays, and so

consists essentially of a 8-bit microprocessor

with

of another 8-bit microprocessor. Isolated communication

opto coupled serial

earthy logic

which is responsible for effective control

control, the real time clock, the

on.

bus

0072g/1634g

1.2

A DRIVE

OHMS

I/P

TERMINALS »

CONTROL

A DRIVE

CONTROL

7151 MULTIMETER FUNCTIONAL BLOCK DIAGRAM

o-

INPUT SWITCHING

A.C.

CONDITIONING

INPUT

AMP

ATTEN. &
GAIN CONTROL

GAIN
CONTROL

FLOATING LOGIC

OPTO COUPLERS

CONVERTER

HOLD OFF

2 WIRE SERIAL

LINK

COUNT

RESET

+/-REF

WATCH-DOG

REFERENCE

AUTO-CAL

MEMORY

TO FLOATING

POWER

RAILS

TO EARTHY

POWER RAILS

FLOATING

POWER

SUPPLY

EARTHY

POWER

SUPPLY

ADDRESS BUS
ENABLE

WATCH-DPG

ADDRESS
LATCHES

At) TO A7

HOLD -OFF

RESET

A8 TO A15

EARTHY LOGIC

AO/DO TO A7/D7

4 COLUMNS

1 COLUMN

CLOCK

KEYBOARD 8.

FRONT/REAR SW.

DECODERS

INTERFACE
DECODERS

4 ROWS

8 ROWS

DATA BUS

SERIAL

KEYBOARD &

FRONT/REAR SW.

DECODERS

INTERFACE SW.

DECODERS

LATCHES

GPIA

DISPLAY

DRIVER

INTERFACE BUS

DRIVER

LEVEL CHANGING

TRANSCEIVERS

TO

■ REAR PANEL
GPIB SOCKET

ANALOG OUTPUT

TO

LEVEL CHANGING

TRANSCEIVERS

REAR PANEL

AUXILIARY SOCKET

7151 MULTIMETER FUNCTIONAL BLOCK

*

DIAGRAM

FIG 1.1

Chapter

Calibration

Procedures

1642g/00'72g

{

I

(

{

1

CHAPTER 2

Setting-Up And Calibration Procedures

General

These procedures enable the instrument to be set-up
factory

despatch

standards

.

and

calibrated to the

The procedures are categorised into the following sections:

1. Setting-up procedures

2. Initial calibration

3. Final calibration

procedures

procedures

Safety

The instrument must be disconnected from the mains supply when
dismantling it to gain access to the preset controls and also
being reassembled (see

Chapter 4 for dlssembly instructions)

when it is

.

When adjusting preset controls beware of high test voltages, the guard
potential on the guard plate and also the mains input supply.

Calibration Method

Owing to the automatic calibration circuits incorporated in 7151, it can
only be calibrated by connecting it to a remote controller and then using

the appropriate calibration commands.

program can be used which is a
Solartron

can

supply, on tape cassettes, a calibration program for the

much faster method of calibrating 7151.

Alternatively, a calibration

more common types of controllers.

The user is advised to re-calibrate 7151 annually.

If the instrument's existing
satisfactory, the user can
constants by sending the REFRESH

state of calibration is judged to be

simply re-write the existing calibration

command to 7151 once it is in the

calibration mode.

Calibration Source

It is recommended that the calibration source has an accuracy of at least
two times better than the accuracy specified for the various 7151
functions. The 7151 specification is given in the Operating

Manual and

the important percentage accuracies are as follows:-

DC Volts

DC Current
AC Volts
AC Current
Resistance

0.002%

0.02%

0.05%

0.05%

0.002%

0072g/1624g

2.1

ENTERING CALIBRATION MODE

Insert a shorted 2.5mm jack plug Into the rear panel
the front panel CAL Indicator to repeatedly flash. The short may be

CAL socket, causing

within the plug Itself, or externally via a switch. The plug must remain

fitted throughout the calibration, and can be removed after calibration
is complete.

Note: Do not switch mains power on or off when the shorting plug Is
fitted, otherwise the Internal calibration

Using the controller, send the command CALIBRATE
Into the

calibration

mode. The

CAL Indicator should then be steady.

Also displayed Is the word, 'CAL'. Once the calibration mode

constants may be

ON to 7151, putting It

altered.

has been

selected, the following conditions apply:

(a) Three commands cannot be used: TRIG

TRACK

NULL

'OFF' status Is adopted.
'OFF' status Is adopted,

all nulls being deleted.

(b) Four commands become available: HI

LO
WRITE
REFRESH

for refreshing

existing

cal. constants.

0072g/1624g

2.2

CALIBRATING MEASUREMENT RANGE

Using the controller, select the function and range to be calibrated by
sending the appropriate MODE and RANGE commands.

7151 must then be supplied with two precisely known reference inputs

(non-negative) one at approximately nominal full scale (referred to as

the Hi point), and

one at approximately zero (referred to as the Lo
point), in the case of ac ranges the Lo point should not be less than
approximately 5% of nominal full scale rather than zero. This ensures

that all inputs are within the optimum part of 7151's

linear range.

After a reference input is applied, 7151 must be informed of the precise
value of the input. This is achieved by using the HI command for a Hi
point, and the LO command for a Lo point. These commands must be

accompanied by an integer argument number, of up to six digits in length,

which expresses the applied input in terms of 5 x 9's count.

An integer value of 200000 corresponds to nominal full scale for any

range

For example, applying 2V on the 2V range, enter 200000

.

applying 20V on the 20V range, enter 200000
applying 5V on the 200V range, enter 005000

Apply the Hi point input to 7151 for the requisite function/range.

For example, 2.00843V on 2V dc range.

Using the controller, send the HI command to 7151.

For example, HI200843.

7151 responds by displaying 'Hi Pt' for about 1.5 seconds, during which
time it measures the applied reference input. When finished, the
instrument displays (and outputs) its measured count, e.g. 214576. It is

of no consequence if the displayed count differs from the applied input.

Repeat the above

(short circuit), and send the LO command. For example LOO (leading

zeroes need

Having
command

specified the Hi point and Lo point (in any order), send the

WRITE to 7151 (no argument required). This causes the
calibration constants for the selected range/function to be calculated
and

stored in memory. If successful, the message 'Good' is displayed.

If unsuccessful, an error message will be displayed and output to the

procedure for the Lo point. For example, reference = OV

not be specified).

controller.

Repeat the above instructions for each function/range to be calibrated.

0072g/1624g

2.3

RESTORING THE MEASUREMENT FUNCTIONS

Using the controller, send 7151 the command CALIBRATE OFF. The CAL

indicator will then flash indicating that the CAL shorting plug is still

fitted.

Withdraw the CAL

shorting plug. The

CAL indicator should then be

invisible, the instrument being ready for normal use.

SUMMARY

(a) Insert CAL shorting plug (2.
(b) Select the calibration mode by sending the CALIBRATE ON

5mm) in rear panel socket

.

command.

(c) Select the requisite function and range to be calibrated and perform

the calibration sequence. Repeat for each range/function to be

calibrated.

(d) De-select the calibration mode by sending the

CALIBRATE OFF

command.

(e) Remove CAL plug.

0072g/1624g

2.4

Setting-Up

Procedures

DC Power Supply Checks

Measure the dc supplies on PCB1 and PCB2 at the output pins of the
appropriate regulator IC's. Tolerances of the most important supplies,
mains voltage 240V, follow:

floating 15V unregulated
floating 15V regulated
floating 5V unregulated

floating 5V regulated
earthy 5V unregulated
earthy 5v regulated

between 20.7V and 21.6V

15 ± 0.75V

between 8.8V and 9.1V

5 + 0.25V

between 9.5V and 9.8V

5 ± 0.25V

Display Checks

The contrast of the display can be adjusted

by means of RV301. Make the

digits appear as black as possible but without introducing slurring when

a reading changes.

Keyboard Checks

The following sequence exercises all 16 keys.

Key Press

FILT 2 press minimum

Display Response

"FILT" on/off

Finish with "FILT" off
ma-
mA===

K£2

V~
V===
AUTO 2
V
A
LOCAL

presses

minimum

KQ

V~
V===

"AUTO" on/off
Check for downranging
Check for upranging

"GPIB nm" where nm is address
value.

NULL 2 presses minimuim
6x92

TRACK 2

presses
presses

minimum
minimum

SAMPLE with "HOLD" asserted

COMPUTE
MENU

"NULL" on/off

"6x9" on/off

"HOLD" on/off

“

HOLD" goes out briefly and

returns

.
"NO PROG"
“

PROBES?"

0072g/1624g

2.5

Initial

Calibration

Procedures

Test Equipment

1. General purpose DMM.

2. General purpose oscilloscope

3. Controller, e.g. Commodore PET fitted with BASIC III or BASIC IV
firmware.

4. Calibrator, e.g. Fluke 5101 fitted with GPIB interface.

5. ACV Calibrator, e.g. Hewlett-Packard 745.

6. ACV High Voltage

7. Capacitor O.lyF polypropylene attached to a twin 4mm banana
(3/4" centres)

Switch on 7151 and

Amplifier e.g. Hewlett-Packard 746.

.

allow to warm up for at least one hour before

plugs

calibration.

The initial calibration

Table

2.1

No.

2.2

2.3

2.4

procedures are detailed in the following tables:

Procedure
Initial
Initial
Initial
Initial

calibration, DC
calibration, Resistance
calibration. Current
calibration, AC Volts

Volts

Please

Note: The limits of error expressed in the following tables are

those adhered to by the factory for a new instrument. As an instrument

'ages', "components become more noisy or their tolerances increase.

Therefore, when calibrating a used instrument, it may

be

necessary to
accept limits of error that are marginally higher than those listed in
these pages. However, the instrument should always conform to the

commercial specification (see Operating Manual) after calibration.

0072g/1624g

2.6

Table 2.1 Initial Calibration, DC Volts

TEST RANGE & INPUT

ACTION

LIMITS

COMMENTS

MODE

1 Configure the rear panel interface switches and connect the controller to

7151.
Do

not insert the calibration Key Jack yet. FRONT/REAR switch to 'FRONT'.

2

3

4

5

6

7

2VDC

2VDC

0.2VDC

s/c link

VHI-VLO

front

s/c
VHI-VLO
Front

o/c

Power on

Insert Calibration
Key Jack

Adjust RV3.
DVM between link

& ROME

Check display ^

'for2scatter

Check reading

± 100 yV

3 adjacent
values

0 ± lOOyV

I/P amp gross
offset null.

2V range noise test.
The reading may jump
every 10 secs at

drift-correct

Input current
measurement.
may be exceeded at
drift-correct

.

Value

.

10

11

12

13

8

9

2VDC

2VDC

2VDC

2VDC

0.2VDC

20VDC

4V< plus
overload
< -100V

-4V< minus
overload
< -100V

±1,99999V

alternatively

+

1.99999V &

0.00000V

0.

199999V &

0.00000V

+19.

9999V &

0.00000V

Measure C4 with

DMM referred to

ROME

As above

Adjust RV1
CAL BAL

Do calibration

routine over the
interface

Do calibration

routine over the
interface

Do calibration

routine over the

interface

+3.90
+3.05

-3.05

-3.90

+ and -
equal within

1 bit

Positive input-clamp
test (D6)

Negative input-clamp

test (D26)

Cal. Bal Adjustment
Use continuous
drift-correct (Yl)

.

+2V set-up

+2V set-up. Use the
calibrator to deliver
0 volt

.

+20V set-up.

0072g/1624g

2.7

Table 2.1 Cent.

TEST RANGE & INPUT

MODE

14 200VDC +199.999V &

0.00000V

15 IkVDC +10000.

00V &

0.00V

16

17 2VDC +1.00000V

-1.00000V

ACTION

Do calibration

routine over the

LIMITS

COMMENTS

+200V set-up.

interface

Do calibration
routine over the
interface

+lkV Set-up. The

Calibrator LO and the

7151 LO input should

be mains grounded.

Check that the

spark-gap does not
operate. Apply for

1 minute and check

that the reading

does not drift more

than 2 bits.

Exit Cal Mode

Measure

+2 bits
pos-neg
error

Linearity. Change
polarity changing
over inputs.

0072g/1624g

2.8

Table 2.2 Initial Calibration, Resistance

TEST

1

2

3

4

5

6

7

RANGE
MODE

20kfl

200kfl

2Mfi

2k£2

20kfi

200kfi

2Mft

5. INPUT

DMM between

I- and LO

As above

As above

l.OOOOOkfl

and IQ

lO.OOOOkQ

and IQ

lOO.OOOkQ
and IQ

1.00000MQ

and IQ

ACTION

Measure current

LIMITS

100±5yA

COMMENTS

from -I.

DMM set to current.

As above

As above

Do calibration

10.0 ± 0.5uA

1.0 ± 0,5yA

2KQ range set up

using the interface

Do calibration

using the interface

Do calibration
using the interface

Do calibration
using the interface

20KQ range set
up.

200KQ range set
up.

2MQ range set up
O.lyF in
parallel will
reduce scatter
caused by series

mode interference.

10

11

12

8

20MS2

10.0000MQ
and IQ

Do calibration
using the interface

20MQ range set
up. O.lyF in
parallel will

reduce scatter.

9

2M$2

DMM across
7150 HI & LO

2M£2

240VAC
/ 50 Hz

2Mfi

1.00000MQ

Measure the o/c
volts from Q
source

.

Apply VHI-VLO

10 seconds.

Check after test 9

+5.2V ± IV

1.00000MQ
±100 bits

Q source

positive clamp.

Ohms overload test

Survival check for
damage after test

10.

DV

Auto

+1 kV
applied 5

times

Check display

± 10 bits

IkV step input

test. LO

GUARD must

connect to LO of

Cal. and also to

and

mains ground.

7151 must uprange

withou power

restarts. It is

permissible that

the spark-gap

operates.

0072g/1624g

2.9

Table 2.3 Initial Calibration, Current

TEST

1

2

3

5

RANGE
MODE
DC A

AC A

DC AC

& INPUT

+1.00000A &
open circuit

400 Hz

1.99999A &

0.19999A

+1.99999A

ACTION

Calibrate over the

LIMITS

COMMENTS

1 Ampere Set-up

bus

Calibrate over the

2 Ampere Set-up

bus

Exit Cal Mode

Measure voltage at
current front
sockets with

a

0.80 volt

Burden

DMM.

0072g/1624g

2.10

Table 2.4 Initial Calibration, AC Volts

TEST

1

2

3

RANGE &
MODE

VAC

various
ranges

20VAC

20VAC

INPUT

s/c

19.9999V

400Hz

19.9999V

50kHz

ACTION

Adjust RV2 for
minimum @

TP3

Note reading

Adjust CV1 St R10

for flat response

LIMITS

±150 bits

referred to
OV

Value at test

12'

±0.0

10V

COMMENTS

IC15 offset null
adjust.
to monitor TP3
Transformer

Use

DMM

lamination to be

mains-grounded.

The lowest figure
possible is
required; if
necessary by
error-sharing
among the ranges

Attenuator HF

trim. 100 bit
limit applies

when a dummy lid

is fitted.

.

10

4

5

6

7

8

9

0.2VAC

2VAC

20VAC

200VAC

IkVAC

0.2VAC

0.199999V &

0.019999V
400Hz

1.99999V &

0.19999V
400Hz

19.9999V S>

1.9999V
400Hz

199.999V S.

19.999V

400Hz

750.00V &

199.99V
400Hz

30KHz

0.199999V

Calibrate over the
bus.

Calibrate over the
bus.

Calibrate

bus.

Calibrate over the
bus.

Calibrate over the
bus.

Exit Cal Mode

Check

over the

0.
.000120V

199999V ±

0.2V LF
Fluke 5101.

2V LF Set-up

20V Set-up

200V Set-up

1 kV

Set-up

Set-up

11

0072g/1624g

0.2VAC

lOKHz

0.199999V

Check

2.11

0.

199999V ±

,000096V

Table 2.4 Cent.

TEST

12

13

14

15

16

17

18

19

RANGE &
MODE
2VAC

2VAC

20VAC

20VAC

200VAC

200VAC

IkVAC

Ik VAC

INPUT

10kHz

1.99999V

30kHz

1.99999V

30kHz

19.9999V

10kHz

19.9999V

10kHz

199.999V

30kHz

199.999V

10kHz

750.00V

30kHz

750.00V

ACTION

Check

Check

Check

Check

Check

Check

Check

Check

LIMITS

1.99999V ±
.00096V

1.99999V ±
.00120V

19.9999V ±

0.0120V

19.9999V ±
.0096V

199.999V +

.096V

199.999V ±

0.120V

750.00V +

0.46V

750.00V +

0.70V

COMMENTS

20

21

22

23

24

25

26

27

0.2VAC

2VAC

2VAC

2VAC

2VAC

2VAC

20VAC

200VAC

s/c

10Hz

2.00000V

20Hz

2.00000V

40Hz

2.00000V

100Hz

2.00000V

100kHz

0.19999V

100kHz

20.0000V

100kHz

200.000V

Check

Check

Check

Check

Check

Check

Check

Check

150yV

2.00000V ±

0.01456V

2.00000V ±

0.00416V

2.00000V ±

0.00096V

2.00000V ±

0.00880V

0.199999V ±

0.000880V

20.0000V ±

0.0880V

200.000V ±

0.880V

s/c zero.

Trasnsformer

laminations to be

mains-grounded.

0072g/1624g

2.12

Table 2.4 Cent

.

TEST RANGE & INPUT

MODE

24 2VAC

Auto

750V/400HZ Check
applied 5

times

ACTION

LIMITS

750.00 ±

0.46V

COMMENTS

750VAC

Autocange

test. Lo and

GUARD

must

connect to LO of
Calibrator and
also mains
ground. 7151
must uprange with
no signs of
distress.

0072g/1624g

2.13

Final Calibration Procedures

7151 should be fully cased and

four hours and switched on for at least two hours prior to final

calibration. GUARD and LO should

placed in a

20,,C

environment for at least

be mains-grounded to minimise

series-mode interference. For this reason, use of the screened leads is

essential for HI fi measurement.

Note that the four screws which retain the top
be fully tightened to make the case screening

section of the case

effective.

must

The final calibration procedures are detailed in the following tables;

Table

2.5

2.6

2.7

2.8

2.9

2.10

No.

Final
Final
Final
Final
Final

Other

Procedure
calibration, DC Volts
calibration. Resistance
calibration, AC Volts
calibration, Current
calibration, Recheck

Checks

Q072g/1624g

V.

2.14

Table 2.5 Final Calibration, DC Volts

TEST

1

2

3

4

5

RANGE &
MODE

0.2VDC

2VDC

20VDC

200VDC

IkVDC

INPUT

+0.100000V &

0.000000V the bus

+

1.9999V &

0.000000V

+19.

9999V &

0.000000V

+199.

+1000.00V
Sc

999V Sc

0.000000V

o.oov

ACTION

Calibrate over

Calibrate over

the bus

Calibrate over

the bus

Calibrate over

the bus

Calibrate over

the bus.

LIMITS

200mV range Cal. zero

volts to be

commanded from

Calibrator.

2V range

volts from
Calibrator on its 2
volt range.

20V range

volts from
Calibrator on its 20
volt range

200V range Cal. zero

volts from
Calibrator.

COMMENTS

IkV range

Cal. zero

Cal. zero

.

Cal.

0072g/1624g

2.15

Table 2.6 Final Calibration, Resistance

TEST

1

2

3

4

5

RANGE &
MODE

2KS2

20142

200142

2M£2

20M$2

INPUT

1K$2 & IQ

10142 5. IQ

100142 &

IS

IMS &
IB

10MB &
IB

ACTION

Do calibration
over the bus

Do calibration
over the bus

Do calibration
over the bus

Do calibration
over the bus

Do calibration

over the

bus

LIMITS

COMMENTS

4 terminal connection

4 terminal connection

to be used.

Use screened lead

Use screened lead

0072g/1624g

2.16

Table 2.7 Final Calibration, AC Volts

TEST RANGE & INPUT

MODE

1 0.2VAC 0.

2 2VAC

3 2QVAC 19.9999V

4 200VAC 199.999V

5 IkVAC 750.00V

199999V

& 0.0199999V
400Hz

1.99999V
& . 19999V <a
400Hz

& 1.9999V @

400Hz

& 19.999V @
400Hz

& 199.99V
400Hz

ACTION

Do calibration
over the bus

Do calibration
over the bus

Do calibration

over the bus

Do calibration
over the bus

Do
over the bus

calibration

LIMITS

COMMENTS

0072g/1624g

2.17

I

Table 2.8 Final Calibration, Current

TEST

1

2

RANGE &
MODE

2ADC

2A AC

INPUT

1.00000A

and o/c

1.99999A
& 0.19999A
400Hz

ACTION

Do

calibration

LIMITS

COMMENTS

over the bus

Do calibration
over the bus

0072g/1624g

2.18

Table 2.9 Final Calibration

Recheck (Filter In)

TEST

1
2
3
4
5

6

7
8
9

10
11
12
13
14
15

16
17
18
19
20
21
22
23
24

RANGE & MODE

2ADC
2AAC
2k®

20k$2
200k£2
2MS2
20MS2

0.2VAC
2VAC
20VAC
200VAC

Ik VAC

0.2VAC
20VAC

0.2VDC
2VDC
20VDC
200VDC
1 kVDC
1 kVDC

200VDC
20VDC
2VDC

0.2VDC

INPUT

1.00000A

1.9999A/400HZ
l.OOOOOKfi
lO.OOOOkQ
lOO.OOOkfi
l.OOOOOMfl
lO.OOOOMfi

0.199999V 400Hz

1.99999V 400Hz

19.9999V 400Hz

199.999V 400Hz

750.00V 400Hz
IQ (short circuit)

19.9999V 50kHz

+0.

199999V

+

1.99999V
+19.9999V
+199.

999V

+1000.

-10000.

00V

00V

-199.999V

-19.9999V

-1.99999V

-0.199999V

LIMITS

20 bits

100 bits
4 bits
4 bits
5 bits
5 bits
40 bits
100 bits

100 bits

100 bits
100 bits

46 bits
250 bits
300 bits
6 bits
6 bits
6 bits
6 bits
4 bits
4 bits

6 bits
6 bits
6 bits
6 bits

0072g/1624g

2.19

Table

2.10 Other Checks

TEST

1

2

3

4

5

6

RANGE &
MODE

DC Auto

AC Auto

INPUT

1.5kV max.

See Fig.

See Fig.

25 Ampere
5 seconds

1.5kV rms

2.1

2.2

ACTION

Do flash test

Check

Display

Check Display

Perform earth
continuity test

Fit mains fuses
appropriate to

supply voltage.

Flash Test LO to

Earth.

LIMITS

0 + 500yV

0 ± 340yV

0.5Q

250mA SLO
BLO or 100mA
SLO-BLO

COMMENTS

Safety test to IEC

348. Refer to
Solartron
Specification
09/00/105.02. Power

switch

DC Common

ON.

Mode

Rejection 120dB.

AC Common Mode
Rejection 120dB.

As Test 1.

Q072g/1624g

2.20

Figure 2.1 DC Common Mode Rejection

+ O

500V

Figure 2.2 AC

Mains O
Line

Common Mode

lOkfi

IkQ

Rejection

external
LINK

7 V HI

9

v

LO

^ GUARD

> V

HI

7151

MULTIMETER

7151

MULTIMETER

Ikfi

3 V LO

S GUARD

0072g/1624g

2.21

Chapter 3

Dismantling & Reassembly

1642g/0072g

(

CHAPTER 3
DISMANTLING AND REASSEMBLY

3.1 GENERAL

The 7151 must be disconnected from the mains supply before proceeding

with these Instructions.

3.2 DISMANTLING

1. Pivot the

carrying handle to the rear of the case. Pull out the
handle lugs from the pivot points on each side of the case and remove
the handle.

2. Remove the four screws from

the bottom of the case and then

withdraw

the top section of the case to expose the copper track side of PCB 1.

3. Compress the two plastic snap fasteners, located on
side of PCB 1 (as viewed from the unit front) to release the pcb.

Pivot the pcb outwards to gain access to the board components and to

the right hand

expose the screening pcb and the mains transformer.

4. Remove the two screws from the holes located in the mains transformer
laminations and withdraw the complete instrument assembly from the

bottom section of

the plastic stand-off fasteners which retain the screening

the case. PCB 2 can now be accessed by unclipping

board to

PCB 2.

5. At the left of the front panel assembly, remove the self-tapping

screw which secures the front panel assembly to a clip on PCB 2.
Unplug the front panel assembly from PCB 2.

6. To gain access to PCB 3, remove the six screws
to the front panel. Note that PCB 3 remains attached to the front

which

secure the pcb

panel by the keyboard ribbon cable.

3.3 REASSEMBLING

1. Fit PCB 3 to the front assembly using the six screws.

2. Carefully plug the front panel assembly into PCB 2. Check that all
of the connecting

pins on the front panel assembly are correctly

inserted into the socket pins on PCB 2.

3. Fit the self-tapping screw which secures the front panel assembly to
PCB 2.

4. Attach the screening pcb to PCB 2 by use of the plastic stand-off
fasteners.

5. Insert the complete instrument assembly into the bottom section of
the case. Insert the two screws into the holes on the mains
transformer laminations and tighten to secure the

bottom section of

the case.

00072g/1626g

3.1

F

6. Secure PCB 1 by

use of the two plastic snap fasteners located on

right hand side of the pcb.

7. Dress the cables on the top
in the

board which locate the extended lugs in the top section

of the screening board clear of the holes

case.

8. Insert the top section

of the case onto the instrument assembly and
secure the top section to the bottom section by the four screws
inserted into the

bottom section

of the case.

NOTE: It is important that these four screws are fully tightened
otherwise the case screening is made ineffective and consequently the
ac calibration

9. Fit the

handle by lining up the locating lugs on the handle with the

could be impaired.

pivot points on each side of the case and then press the handle lugs

into the pivoting points on the case.

the

of the

00072g/1626g

3.2

REAR PANEL SECTIONS

f

The instrument pictured is not 7151, but a similar instrument and is
intended only to show the functional assembly

.

7151

DISMANTLED

FIG 3.1

Chapter 4 Circuit Descriptions & Diagrams

Page No.

4.1

4.2

4.3

4.4

Contents

General

Measurement of voltage, dc

Measurement of voltage, ac

Measurement of resistance

Measurement of current

Input amplifier

Drift correction

Input protection

Analogue to digital converter

Reference supply

4.5

4.6

1642g/0Q72g

Floating

Logic

Earthy Logic

CHAPTER 4

1. GENERAL

CIRCUIT DESCRIPTIONS AND DIAGRAMS

All multimeter inputs are at some stage processed

by the Analog to

Digital Converter (ADC) whose operating range is limited to ±2.6V. The

range of measurement is extended beyond this figure by
to the 2V range. For example, a

would

be seen by the ADC as only 2V. Non-dc inputs must of course

200V

input scaled

by a

scaling all inputs

factor of 0.01

undergo conversion to dc as well as attenuation and scaling.

2. MEASUREMENT OF VOLTAGE, DC

The dc voltage input attenuator consists of the resistors R1A to RID.
The attenuator is switched by FETs TR7, TR8, and relay

range control inputs from the floating logic. The attenuator setting,

RLK in response to

xl, xO.Ol, xO.OOl depends upon the selected voltage range, i.e.

Range(V)

0.2

,

2

20

,

200

1000

Attenuation

xl
xO.Ol
xO/001

Circuit Path
Direct to input amp. via RLE
RLK, TR7, with RLE open
RLK, TR8, with RLE

open

The attenuated outputs are then amplified by the input amplifier, whose
gain is arranged to

be xl or xlO to ensure satisfactory scaling at

the

ADC.

Input switching - The dc voltage inputs to the input amplifier are

selected via the series FET TR7 and the shunt FET TR6. With TR5 on, TR6

is off, and vice versa.

TR6 is switched
current measurement,

on during ac

and

during 'drift correct

(voltage or current) measurement,

'.

during dc

3. MEASUREMENT OF AC VOLTAGE

For Vac operations, inputs are first scaled to the 2V range

by the ac

signal conditioning circuits and then converted into a dc voltage.

AC inputs are subject to the ac input attenuator which is switched by

IC18, TR1, TR2, and by the op. amp. IC15. It's gain is set,

via IC18 to
be either xl or xlO. For inputs on the 2V range, no conditioning is
required; quad analog switch IC18 selects the gain of IC15 (via the

matched resistors R21A and R21B) to be set at unity, with inputs to the

amplifier passed through RLA, RLE and RLF contacts. The overall circuit
gain for other input ranges is selected by TR1 and IC18 in response to
range and control inputs from the floating logic.

Range(V)

0.2
2

20

200

1000

Attenuation

xl
xl
xO.Ol
xO.Ol
xO.OOl

Amp. I/P(V)

0.2
2

0.2
2
1

Gain

xlO

xl
xlO
xl
xl

Amp 0/P(V)

2

2
2
2

1

IC21. The

DC conversion is performed by the

true rmsto dc

maximum 2V output from this IC is switched to the dc input

converter

amplifier IC1 via the shunt input FET TR6 and via quad analog switch ICS.
1639g/0072g

4.1

4. MEASUREMENT OF RESISTANCE

This is achieved by measuring the voltage developed across the unknown

resistance when a

voltage is then measured by the dc voltage measurement circuit.

Current Generator

IC3 is a

supply from the reference circuit. The

reference. Thus IC3 drives TR3, maintaining a IV differential across the

resistors R73, R74, R75 and R15. Control inputs from the logic circuitry
switch this resistor chain (via TR4, TR9, and
currents. The test currents for the various ranges are:

Mhen checking
available at the Hi ohms source terminal is returned via the Lo ohms
source terminal.

For the ranges other than 20MS2, the logic control, via IC2, also
switches in the resistor chain R7, R27 and R56
the Lo ohms source terminal and the -3.1V reference. This part of the
circuit acts as a calibrated

precision operational amplifier to

Nominal Range

20MQ

200k$2

20kS2

4-wire

Circuit

2MQ

2kQ

known

current is passed through it. The resultant

which is connected the +1QV

other amplifier input is the +11V

RLD) to define four test

Test Current

lOOnA

luA

10uA
lOOvA
lOOuA

measurement circuits ensure that all current

which is connected between

current sink for the test current generator.

Protection
R4 (22k) which is in series with both the 1+ and V+ input terminals.
Diodes D2 and D25 limit the

-2.6V.

5. MEASUREMENT OF CURRENT

This is achieved

resistance when the unknown current passes through it. The voltage

obtained can be measured by the dc input amplifier directly or for ac

inputs, via the AC-DC

DC Current Input

Resistor R3 is a 0.1$) shunt through

flows. The

via the quad switch ICS and shunt FET TR6. The gain

for dc current; the amplifier output is thus correctly scaled on the 2V
range for

AC Current Input

For ac inputs, the potential across resistor R3 is switched, via the quad
switch IC18 and FET TR2, to the ac operational amplifier IC15. The gain

of IC15 is set to xlO for ac current inputs; thus the inputs to the AC to
DC converter are scaled to the 2V range. After AC to DC conversion, the
output voltage is switched to the dc input amplifier via the quad switch

ICS and shunt FET TR6.

of the resistance

by

measuring the potential produced across a known

converter.

potential across R3 is switched to the dc input amplifier IC1

A to D conversion.

measurement circuit is provided by resistor

voltage of

TR3 and R4 to between +5.3V and

which the current to

be measured

of IC1 is set to xlO

Protection agains excessive current is by the 2A fuse, FI.

1639g/0072g

4.2

6. INPUT AMPLIFIER

Input amplifier IC1 is a precision FET input operational amplifier.

Signals for IC1 are firstly amplified

by the dual FET pre-amplifier,

TR13, whose bias is provided by transistor TR14 and diode D7.

Inputs to the pre-amplifier are selected

(series FET) or TR6 (shunt FET) depending on the selected multimeter

function. For dc measurement functions (including resistance) TR5

either by switching on

TR5

conducts; for ac functions, or during drift corrections, TR6 conducts.

The gain of the pre-amplifier is controlled by IC2 in response to range
control signals from the floating logic. IC2 is a quad

analog

switch

connected across IC1 feedback resistors R18 and R19. The switching of

IC2 sets the overall gain of the pre-amplifier and IC1 to be xl or xlO
depending on the selected input range or measurement function. The gain
settings can be summarised as follows;

for DC

voltage

ranges

for DC

current range

Range (V)

0.2
2

20

200

1000

Range (mA)

2000

Gain

xlO
xl
xlO
xl
xl

Gain
xlO

for AC

current range

Range (mA)

2000

Gain

xl

7. DRIFT CORRECTION

A 'drift correct1 is
originating in the input amplifier or from

necessary in order to compensate for any drift

the ADC. Typically, drift

results from component aging or temperature fluctuations.

During a drift correct cycle, the input amplifier is isolated from any
measured input (series FET TR5 off) and connected to signal OV (shunt FET
TR6 on). With
due to drift. This is subsequently subtracted from a

zero input to the amplifier, any resultant count is then

measurement count

to provide a final count (i.e. result) free from error.

8. INPUT PROTECTION

Protection against voltage overload of the input amplifer is by spark-gap
SG2 (1400V nominal) which is connected across the VHI and VLO terminals.
Resistors R9 and R25 form a

current limiter, and

diodes D6 and D26 limit

series inputs to the amplifier to ±2.6V.

1639g/0072g

4. 3

9. ANALOGUE TO DIGITAL CONVERTER (ADC)

This circuit converts the
digital pulses.

These

analogue output from

are used to gate

clock into a reversible counter

the input amplifier into

in the MPU, IC103, to produce a count proportional to the measured input

The Integrator
The integrator, ICS has the following inputs connected to its summing
point:

1. The input to

be measured

2. The forcing waveform

3. + reference or - reference

With zero input applied to the

waveform applied continuously to the integrator, the

alternately positive and

negative through the thresholds of the

multimeter and a 300Hz forcing square

output is driven

comparators IC9 and IC10.

The states of the two comparators are followed by the bistable, IC11

which

synchronises the transistors to a clock. The outputs from IC11

control the analogue switch IC16 which switch the + and - reference

supplies (through OV) to the integrator input. This closed loop feedback

arrangement ensures that the output is always dynamically balanced about

zero.

.

The synchronised output of the bistable, IC11, is also
passed to IC103 where the

pulses are counted.

NANDed by IC17 and

10. REFERENCE SUPPLY

This circuit generates the +10V
generator and the + and -3.1V supplies for the ADC. The reference

D20, together with the resistor network R38, R42, R17 and RV1, ensures

and +11V supplies for the ohms current

diode,

the input to IC4 is held at 3.1V. D20 also forms the + reference supply,

via IC6a and IC16, for the

ADC. The output of IC4 forms the -3.1V

reference supply.

All references are with respect to the 0V ROME.

The + reference voltage is also used as the input to IC6b. This is an
amplifier which drives a current through-R14, R57 and R16 in

order to
maintain the reference at balance. The resistor chain is tapped to
provide the +10V and +11V reference voltages for the
generator

.

ohms current

1639g/0072g

4.4

11. FLOATING LOGIC

This circuit includes the floating logic microprocessor (MPU),
This IC communicates with the earthy logic MPU

via a 2-wire optically

IC103

.

coupled serial link. The circuit can be considered to have four separate
functions:

1. Controls range and

mode switching on

the analogue pcb.

2. Generates the forcing waveform for the ADC.

3. Counts the pulsed output from the ADC.

4. Stores calibration constants and checksum for use during auto-cal
procedures

Note:

The circuit automatically resets to a known state in the event

.

of a system lockout.

11.1 Analogue Control Lines

These MPU outputs are connected to drivers, comparators and bi-lateral
switches on the analogue pcb. The outputs, via their respective
switching

devices, correctly configure the circuits for the selected

multimeter range and function.

11.2 Forcing Waveform
The "timer-out"
generate the forcing
signal is converted into a 0 to 8V

signal from the MPU is a 300Hz waveform which is used to

waveform for the A to D converter.

square wave by

the bi-lateral switch

The TTL level

ICS in the analog circuit.

11.3 Counting Circuit
Timer-in is an input to the MPU which is derived from the ADC. The input
is a single, clock synchronised
alternatively, the length of

pulse-train; the pulse widths indicating

time the + and - reference voltages were
applied in order to balance the integrator. Within the MPU, these pulses
are used to gate clock into a reversible counter to produce a nett count

proportional to the measured input

.

11.4 Non-Volatile Memories
IC’s 105 and 106 are EAROMs which hold the automatic calibration program
for the multimeter and the calibration constants for each mode/range

selected.

11.5 Reset Watchdog
This circuit causes the floating MPU to be reset in the event of system
lockout.

The circuit operation is similar to that described for the

earthy logic reset circuit (page 2.11).

A 1.2288 MHz clock derived output from the MPU is divided by a 12-bit
binary counter IC 107. The 300Hz (3.33ms period) output from

this IC is

counted by the 4-bit counter, IC108.

The serial link TX DATA line from the ea

IC108. This input holds off the RESET output unless the RX DATA line is
inactive for more than 26.664ms (8x

period)

rthy

MPU, is also connected to

.

With the RESET line active, bistable IC112 (see ADC) is also reset,

thus

MPU pin 8 (TIMER IN) is set to a logic 1 state. Pins 8, 9, and 10 are

set to this state at initialisation.

1639g/0072g

4. 5

12. EARTHY LOGIC

This includes the microprocessor set, the remote control interfaces, the

watch-dog reset circuitry, the analog to digital converter (analog

output),

clock and the interface switch decoders

.

MPU set

This consists of

IC 212 :

IC 207 :

IC 208 :

8 bit MPU

16K x 8 bit ROM

8K x 8 bit RAM

GPIB Interface

This consists of

IC 203 :
IC 202 :
IC 201 :

IC 203 consists essentially of 15
into by the
to RS2, 8 can be read by

MPU and, depending on the state of

the MPU.

The transceivers IC201 and 202 are bidirectional and consist of eight
driver/receiver pairs

each. Each driver/receiver is enabled by a

send/receive input (T/Rl and T/R2) with the disabled

general purpose interface adaptor
octal transceiver
octal transceiver

registers, 7 of which

control lines R/W and RSO

output forced to a

can be written

high impedance state. All GPU) signals are TTL level.

12.2 RS232 Interface
This consists of IC 204 : RS232 interface adaptor

IC 218 : RS232 line driver
IC 219 : RS232 line receiver

IC204 is essentially a

reversible 8 to 1 line decoder for the
transmission and reception of data via the TxD and RxD lines. IC218 and
219 serve to

buffer and level-shift the various signals to/from

RS232

levels (±12V).

12.3 Analog Output

This is generated by the 8-bit digital to
voltage

between the

Hi and Lo lines should bot exceed +10V, or be less

analog

converter, IC205. The

than OV.

12.4 Address

The

MPU addresses the various bus connected devices and the watch-dog

reset circuitry via the decoder, IC209. The ROM, IC207, is addressed

separately by the

Decoders

A15 (inverted) address line.

12.5 Clock
IC206 is a real time clock which is responsible for generating accurate
time signals for the MPU

and provides control signals for other
circuits. The clock frequency is factory adjusted to exactly 32.768kHz.
If the frequency is to

directly

across the crystal as this will produce a false reading.

Instead, the frequency

suitably buffered and divided by four. i.e. 8.1920kHz±0.1Hz. The

frequency can

be adjusted with C217.

be

checked, test probes must not be placed

should be

measured at

IC206/pin 21 where it is

Whilst the instrument is switched-off,

(pin 22) by the

1639g/0072g

back-up

battery, BAT 201 (approx. 4.5V).

standby power is supplied to IC206

4.6

12.6 Reset Watchdog
This resets the MPU and the display in the event of a system lockout. A

0.6144MHz clock derived
12-bit binary counter IC216. The 150Hz (6.6ms period) resultant output
is checked

by the counter, IC217.

output from the MPU is further divided by

the

12.7 Display and Keyboard

This circuit has two main functions:

1. to decode display and command data

2. to transfer keyboard selections to the MPU

12.8 Display
The display circuit includes custom
undergoes selt-test for approx. 2 secs. The display is of the matrix
type

where it takes both column and
segments (see diagram of display layout).
pulses that alternate about 0V; this ensures that the crystals do not

LCD X301. At switch-on, the display

row

signals to activate

The display is driven by

particular

become permanently polarised.

The driver for the display is IC301 and is serially interfaced with the

'earthy* logic via pins 8->13. With CS (chip select), data can be sent

on the serial input (SI) line. A data bit is sent for every +ve going

transition of SCK; on the eight on, the BUSY line is made low until the
IC is ready to accept more data.

The serial input may just be data for display, in which case the control
data (C/D) line remains in its active low state. However, for driver
commands,

such as blanking or flashing the display, C/D is set to active

high.

12.9 Keyboard

The (vertical) column outputs from the keyboard are connected directly to

the

MPU and, with no selections made, held in the logic 1 state via
pull-up resistors on the earthy logic pcb. Keyboard (horizontal) rows
are scanned via output latch IC210 and BCD-to-decimal decoder,

IC302.

12.10 Power Supplies

Both PCB1 and PCB2 have on-board power-supply regulation, supplied by a

common
the regulated 5V

derived from PCB2's unregulated 5V

mains transformer. The display board logic derives its power from

supply

of PCB2

whilst the display backlighting

power is

supply. The -25V supply of PCB1 can

only be enabled by insertion or a shorted CAL plug, and is reguired to

re-program the calibration constants held in the EAROMs (ICs 105 & 106).

1639g/0072g

4. 7

aep-fA*

I

PCBl,

SHT 1 OF 3,

FLOATING ANALOGUE

DIAGRAM 4,1

BROWN WIRE TO PHS01/11 O-

ORANOE WIRE TO PH50W3 1 O-

/ ^

PH >01

/I

fieo

WIRE TO PH601/?

YELLOW WIRE TO PH501K.

PH1Q1

IL

(

POWER SUPPLY

-cf>

C151

NEGATIVE

NON - VOLATILE

MEMORIES

270

)

IS CONNECTED

3 IS OPEN CIRCUIT

1

PIN NUMBERS

+ 5V OVP -5V -2SV

14

7,21

7

'6

*

-

'

-

>

-

6

-

7

-

-

-

■

-

-

P37 -

P36 i

P35 :

P34 -

P32 ■

P3I j

P30 ■

1C N« DEVICE TYPE

76LS04

10?

HO68P01VOS

103

- IC13/7

» TC14/A

S CONTROL

ANALOGUE

*35,106

107

*36

NC 7033

404066

74LS197

PCB1,

SHT 2 OF 3,

FLOATING ANALOGUE

DIAGRAM 4.2

1C15I

-IC154

IC15I

IC152
1C156

!C153 h

,C,”o7

IC154

IC153

}FD

GROUND

GROUND

^OUTPUT

j

ICI55

IC1S7

WIRES TO PCS

2

j FLOATING'ANALOGUE POWER SUPPLIES

DIAGRAM

4.3

?

5

l

1C214

k

5

5

i

IC215

♦SvfFLOATI

f

- BROWN WIRE

1

1

1

:

Opol7

i

|

-ORANGE WIRE

1C No

201,202

203

206

205

206

207

208

209

210

211

212

213

216

217

218

219

220

221

222

223

226

225

Type4

MC3667

MCS36B8

SY6S51A

A0558

HOU60I8

27128-6

HD6266P15

74US139

76LS376

76W5373

H06301

76LSH5

MC140408

74LS197

SN75190

SN75152

LM339

MCH071B

74 L

500

76L504

76 L5

03

MC16068B

PIN NUMBERS

ov

3V

24

12

20

1

1

IS

—

12

12

—

u

29

— —

16

20

10

20

10

21

1

16

B

16

8

14

—

—

12

—

7

14

16

H

7

16

7

-17V+

—

—

—

—

—

—

—

—

—

—

—

—

— —

9

—

—

—

—

—

—

12V

CMOS POWER

—

—

—

11

—

—

—

—

—

—

— —

—

—

6

16

—

—

— —

—

—

—

-

—

—

—

—

24

—

28

—

—

—

—

—

—

—

—

—

14

—

—

—

1C217

C232
OyOA7

IC222

1C223

1C22-

1

C228

0p0C7

C229
OpOA7

g>-

oe IC220d

SPARE GATES

po

ji>

ov IC221C

R207 NOT USED

PCB2, EARTHY LOGIC

DIAGRAM 4.4

N2V SCHAFFNER FN372-2/

21

QRANQg WIRE

FUSES

SLO-BLO 1

1100/120: 250mA

220/240

:100mA

RED WIRE

> CABLE FORM TO PCBt

IC253

IC25!

IC251

IC257

1

I

i

i
i

DISPLAY BOARD
BACKLIGHTING

EARTHY LOGIC POWER SUPPLIES (5= MAINS POWER)

DIAGRAM 4.5

UNRECULATEO

VOO VDO

IC303(A)

IC303;

T

i

acposs “

ins

fc

AKO 75F inoi

bi

isa'iosof

I

:c302

IC30I

LIQUID CRYSTAL DISPLAY X30I

PLUGS ATI SiO02 AND SK30;

IC302

anna

nnan

□□□□
□□□□

ARE NOT USED

Qe

FRONT VIEW OF PCS

f:ex!9l

£

C0NN5CTQ?
APPROACHES
SK1CLFPCM

THE RIGHT

PIN NUMBERING FOR FLEXI -CONNECTOR

KEYBOARD VlEV.EO
FROM FROfif <«<£ /PADl

□ □ □ □

FACE

□ □an
□ □ □ □
□ □ □ □

PCB3,

DISPLAY AMD KEYBOARD

DIAGRAM 4.6

tDO

&

A

J LJ

-A

j

~7~

^

—7 ™

___z_____

nOA AUTO-HOLD FILT CAL NULL COMP ERR 6X0

7

4

50

26

backpl

ane

®

=

crossover

DISPLAY

DIAGRAM 4.7

segment

plane

WIRING.

^T

OUTER SR&iO

nr

OUTER BRAIO

m

PCB1/0P6 AMI

PC8W0P2 VH[

PCBV0P5 GUARD

PCBW0P3 10

PCB1/0P1 H

PCBVDPA [-

, P/fi LOGIC INPUT

PC93/PAD'S'

TOP VIEW OF SWITCH

o 1

i

FRONT/REAR SWITCH

WIRING

DIAGRAM 4.8

Chapter 5

Fault Diagnosis Guide

1642g/0072g

(

Chapter 5
Symptom

Possible Fault

Procedure

Instrument 'dead*

Fuses keep blowing

'Fail 1' displayed

at power-up

'Fail 2' displayed

at power-up

No mains power

A

good check is to look for the display

backlights. If no lights check fuses

and supply

Rectifier, regulator Correct current drawn from the
or smoothing

for 240V on 240V

voltages.

mains

setting: approx 60mA,

capacitor faulty. for 120V on 120V setting: approx 120mA.

Under fault conditions (regulator
blown) current may typically

be in
order of 500mA. Look for correct
output from each regulator IC.

Communication
breakdown

between

Check opto-couplers IC214 & IC215,

IC102, and the connecting wires and

floating and earthy plugs (to PCB 1). Look for activity on
logic

Problem with

Real- Leave 7151 switched on for 24 Mrs,
time clock IC206,
possibly caused by
battery BAT201 being and on again. If 'Fail 2' still
discharged.

the TX and RX lines.

displaying 'Fail 2', to recharge battery

(or fit a good replacement). Switch

displayed, switch off, remove turret

lug link (if no link, remove battery)
and momentarily
0V to reset the

short IC206 pin 22 to

chip. Also check that
pin 21 is exactly 8.192kHz (derived
from X203)

.

off

Amps range

'does not work'

Display inoperative

Display 'sluggish'
or too faint

7151 doesn't
perform 'correctly'

via remote control,

i.e. perhaps
occasional errors
occur.

2A fuse on rear

Check fuse,

panel blown.

Poor connections

Remake all connections and

verify 100%
between display and contact. Look for the following shaped
IC301, or of the

header PL301 in
socket SK204

waveform on the IC301 outputs

_

SCHS31:

.

Also check the control lines of IC301

(e.g. ensure that RESET is not 'stuck').

Display not

Check setting of RV301 (see P2.5).

correctly driven

Poor contacts in
switch S201, or

fault in interface

chips, IC201, 202,

203 (for GPIB)

or IC218, 219, 204

(for RS232).

Toggle switches S201 to clear their
contacts and set as required. If no

improvement check chips by substitution.

In the case of the

GPIB, ensure that the

correct cables are being used, and

disconnect all instruments other than

the controller to

verify if 7151 is

faulty.

1643g/0072g

5.1

Symptom

Possible Fault

Procedure

After calibrating New cal. constants

7151, it is still haven't been stored

out of

Very

be very difficult to decide where to start looking. However, for PCB1 and
PGB2 there are some basic checks that can be carried out to
search.

Board

PGB 1

calibration, in IC105 & 106.

often a fault will not fall into one of the above categories and it can

Check

All power supplies are within tolerance (see Chapter 2).

Waveform E at

TX and RX of
pins 11 & 12. It is sufficient just to look for activity
on the signal lines.

Forcing waveform of 300 Hz is generated by IC103 pin 9.
Reference

-3.1V respectively.

IC103 pin 40 is 1.2288 MHz.

data from PCB 2 (via opto couplers) on IC103

voltages at IC16 pins 9 & 6 should be 3.1V

Check that -25V is produced
pin 5 when the CAL plug is fitted, and

that it reaches IC105 & 106 pin 1.

help narrow

by IC157

the

and

PCB 2

Waveform at TP4 (IC 16 pin 10) should look like:

|_

RESET from IC 103 pin 6 for activity.

etc.

(

All power supplies.

Waveform E at IC212 pin 40 is 1.2288MHz,

TX and RX of
pins 11 & 12. It is sufficient just to look for activity

on the signal lines.

RESET from IC212 pin 6 for activity.

Pin 21 of IC206 (Real time clock) should be

8.192kHz,

data from PCB 1 (via opto couplers) on IC212

exactly

1643g/0072g

5.2

Chapter 6 Parts Lists &

Component Layout

Page

6.1

6.2

6.9

6.12

6.12

No.

Contents

Parts List abbreviations

PCB 1

PCB 2

PCB 3

Miscellaneous

1642g/0072g

?ri

ir

no£j::e,yqz.:Zi

!?i f1;

5v."iJ i V

3bb;C

orj.'.'WT', t':r'

b.'j.uow. r- '

i.?C*

CHAPTER 6

PARTS LISTS

AND LAYOUT

DIAGRAMS

INTRODUCTION

This section contains component layout diagrams and detailed parts lists

for each of the three printed circuit boards and the front and rear

panels. When ordering

spare parts, it is essential to quote the
instrument serial number located on the rear panel as well as the full
description

of the item given in the appropriate parts list.

A description of the abbreviations used in the parts list is given as

follows:

COMPONENT PARTS LIST ABBREVIATIONS

CIRCUIT REFERENCES

B
C
D
FS
IC
L

LK

PL
R
RL
S
SK
T
TP
TR

X

Battery
Capacitor
Diode
Fuse

Integrated

Circuit
Inductor
Link
Plug
Resistor
Relay
Switch
Socket
Transformer
Terminal Post (or Test Point)
Transistor
Other Components

Also Used:

RV

Variable Resistor

COMPONENT TYPES

Fixed Resistors
CACP
MEFM
MEGL
MEOX
POWW
PRWW
TKFM

Variable
CMPM

0072g/1636g

Carbon Composition
Metal Film
Metal Glaze
Metal Oxide
Power Wirewound
Precision Wirewound
Thick Film

Resistors
Cermet Preset Multiturn

Capacitors
ALME
CARS

GERM

ESTF
ESTM
PTFE
TAND

6,1

Aluminimum Electrolytic
Polycarbonate

Ceramic

Polyester Foil
Polyester Metallised
PTFE

Tantalum Dry

r

PCS

l

(71510501) Floating Logic and Analogue

Cct.

Rl
R2
R3

R4

85
86
67 •
68

89 <
810
811
812

813
814
R15
816

817
818
819

821

Bef.

CAD

1776

Ik

0.1
22k

10k

1.2k

30.9k
100k

47k
990k

9k+lk

3.3k

Ik
1452 1

9k

CAD1776

10k
9k
Ik

9k+lk

J

0.25W

3W

0.5W

0.125W

0.125W

0.25W

3W
2W

0.2W

0.25W

0.25W
matched
P^lr

0.125W

matched
pair

0.2W

General Description

TKFM

5%

0.5%
5%

10%

0.5%

0.25%
5%

2%

0.5%

0.1%
5%

5%

MEOX

PRW

MEGL

CACP
MEFM
MEFM
MEOX

MEGL
MEFM
TKFM

MEOX

MEOX

0.25%

£

TKFM

0.5%

MEFM

0.25%

0.1%

TKFM

Solartron
Part No.

195631000
160300506
176442200

172341000
192731202

192843094
198651000

175244700

160400487

160400582

195633300

195631000
169617201

•

160400583

192741002

169617001
160400582

820

824
822
823

825
826
827

828

829
830
831
832

833
834
635
636

83?
838
R3y

840

100k O
67k J
33k

30k

47k
33k

' 280k

Ik

100
100k
100k
22k

Ik
100

4.7k

4.7k

470k

10k
33k
33k

matched

pair

0.25W

0.125W

3W

0.25W

0.

125V

0.25W

0.25W

0.25W

0.25W

0.25W

0.25 V

0.25W

0.25W

0.25W

0.5W

0.125W

0.25W

0.25W

0.25%
5%

0.5%

2%
5%

0.25%
5%

5% ?

5%
5%
5%

5%

5%
5% -
5%

10%

0.5%
5% t
5%

MEOX
MEFM

MEGL

MEOX
MEFM . ;
MEOX "

■ *

i-''

MEOX "J;
MEOX,x

meox

;;:

MEOX

MEOX :
MEOX

MEOX « ;
MEOX

CACP
MEFM =

MEOX -
MEOX

...

Ci

1

169617101
195643300

••

192743002

175244700
195643300
192852804
195631000

P

c

n

vy:

j

V

'\ ‘‘:

kS.

we.

VJcS.

Wf1"''1 -

i>r:, r

.

-

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o

,

c

c

195621000

195651000
195651000
195642200

195631000

195621000
195634700
195634700

172354700
192741002

195643300
195643300

0072g/1636g

•1 e-V-

6.2

PCB

Get.

R41
R42
R43
R44

R45
R46
R47
R48

R49
R50
R51

R52

R53
R54
R55
R56

R57
R59
R61
R62

R63
R64
R65
R66

R67
R68
R69
R70

R71
R72
R73

R74

R75
R76
R77
R78

1 (cont

Ref.

33k

100

4.7k
470k

100k
Ik

1M
100k

200k

1M
62k
33k

Ik
56
10k

2.7M

10k
27k

180

180

10k
22k
22k
82k

22k
22k

Ik

4.7k

15k

1M
10k
90k

900k

1.0M
1 .OH

1.0M

.)

0.25W

0.125W

3W

0.5W

0.25W

0.25W

0.5W

0.25W

0.125W

0.25W

0.

125W

0.25W

0.25W

0.25W

0.5W

0.25W

0.125W

0.

125W

0.25W

0.25W

0.25W

0.25W

0.25W

0.25W

0.125W

0.

125W

0.25W

0.125W

0.125W

0.5W

0.2W

0.2W

0.3W

0.25W

0.25W

0.25W

'

"' -

General Description

5%

0.5%
5%
10%

5%
5%
5%
5%

0.5%

0.5%

0.5%
5%

5%
5%
10%
10%

0.5%

0.5%
5%
5%

5%
5%
5%
5%

0.5%

0.5%
5%

0.5%

0.5%,.
5% '

0.25%

0.01% '

0.25%
10%
10%

10% x

HEOX

HEFH
HEOX . .
CACP

HEOX
HEOX '

HEOX . ;
HEOX''

HEFH
HEFH

HEFH • •0
HEOX '

HEOX
HEOX
CACP

CACP

HEFH
HEFH
HEOX

HEOX

HEOX
HEOX
HEOX
HEOX

HEFH
HEFH
HEOX

HEFH

HEFH
HEOX

PRWW r:
PRWW

PRWW
CACP
CACP
CACP

"

r

r--u;tc,r

'' ' •

w “

kcC.O

"

r--

-

r

:

.

k

w

-

V..

0

'■

;

-'*=

u' '3 '

192752002
198261002 «?
192746202V1

' 195643300^

195631000

195615600'-
172341000“13
172062700'"

192741004
192742702'

195621800^0

195621800 '»

195641000
195642200
195642200
195648200 -9

192742202
192742202 %
195631000 ^

- 192734702

192741502
193561000 Sfi

160300505 M

160300438 1

160300504

172061000 TJd
172061000
172061000

•

Solartron
Part No.

195643300
192721002 ^
193734700 Sfl
172354700 CH

!>2

195651000
195631000 «!H

193561000
195651000 'S

8A

1

ik

<sl2

'H

•*

^

"Sii

a6?

5T

5.T8

£%

-fl

R79
R80
R81
R82

0072g/1636g

1 .OH
100
100
33

0.25W

0.25W

0.25W

0.125W

10%
5%

5% f

0.5%’'

CACP
HEOX
HEOX

HEFH '

■r*

6.3

172061000

'■

195621000

195621000 v.-.
192713302

»*

Ur'

PCS 1

(cont

.)

Cctl

R101
R103
R104
R105

R106
R151
R152

RV1
RV2

RV3;

RLA
RLE
RLC
RLD

RLE
RLE
RLK .

Ref.

,

15k

270

1.5k
100

100

47k

180

200
200k
2k

relay
relay
relay
relay

relay
relay
relay

0.25W

0.25W

0.25W

0.5V

0.25W

0.25 V

0.25V

0.5V

0.5V

0.5V

GOTO
GOTO
GOTO
GOTO

GOTO

4000

7002

7002
7002

4000

RS12

GOTO 7002-

General Description

5%
5%
5%
1%

5%
5%
5%

10%
10%
10%

MEOX
MEOX
MEOX
MEOX

MEOX "
MEOX

MEOX

multiturn
multiturn
multiturn

-0002

-5005

-5085

-5086

-0002

-5085

cermet preset
cermet preset
cermet preset

Solartron

Part No.
195641500
195622700
195631500
195421000

195621000
195644700

195621800

130922000
110016220
130932000

301203400
301203300
301203500
301203600

301203400
300652190

301203500

Cl
C2
C3
C4

C5, ,
C6

C7

C8

C9
CIO
Cll
C12

Cl 3

C14
CIS
C16

C17(0,
C18 ^

CIS ,

C20 \

C21

C22 ' 5
C23,

C24"1'

200pF

0.22vF
lOnF

470pF

22nF

15nF

0.47uF

0.22vF

15nF
47nF
47nF

lOOpF

47nF
47nF
47nF
luF

2.2yF
47nF
47nF
47nF

47nF

lOyF

.„t,.10yF

>1 6.8pF

500V

400V

1000V

400V

100V

100V

100V

400V
25V
25V

160V

25V
25V
25V

100V

100V
25V
25V
25V

25V
25V
25V
500V

20%
20%

10%

10%
10%
10%
10%

10%
25%
25%
20% >

25%

25%

25%
10%

10%

25%
25%
25%

25%
20% •*
20%
20%

GERM

ESTM
ESTF

ESTF
ESTM

ESTM

ESTM

ESTF
GERM r
GERM
GARB

germ

GERM ‘
GERM

ESTM *

ESTM *
GERM

GERM
GERM

GERM - •
TAND

TAND

3 GERM

241322200
226152200
222841000
208100201

222342200
225441500

225454700
225452200

222341500

—

241944700
241944700

#

v(u.

'

V f

v

ci

208900004

241944700
241944700
241944700

-

W*

\fri'

-S

V;-:

225461000

225462200
241944700
241944700
241944700

a

:

Vf

i

241944700

'•-

208700108
208700108

v';

"-

241306800

0072g/1636g

6.4

1 (cont.)

PCB

•c-) I g>:

Get.

C25
C26
C27
C28

C29
C30
C31
C32

C33
C34
C3 5
C36

C37
C38
C39
040

041
042
C101
0102

Ref.

47nF
47pF

150pF

47pF

3.3yF
47nF
47nF

lOnF

lOnF
lOnF
lOnF

220pF

220pF
220pF
220pF

lOnF

47nF

3.3nF
33pF
33pF

0103 22uF

0104
0105
0106

0107
0108
0109
C110

0111
0112
0151
0152

0153

0154
0155
0156

0158
0159
0160
0161

0163

47nF
47nF
47nF

47nF

47nF

InF

47nF

47nF

lOOpF
2200yF
220yF

lOOOyF
470yF
lOOyF
lOOyF

lyF
lyF
lyF
lyF

lOOnF

25V
500V
500V
500V

100V
25V
25V
25V

:'lr.

25V

■ 25V
25V
500V

500V
500V

500V
25V

25V

-
500V

500V

16V
25V
25V
25V

25V
25V
500V
25V

25V
500V
16V
16V

40V
40V
25V
25V

35V
35V
35V

35V

50V

; General Description

25%
20%
20%
20%

10%
25%
25%

25%

25%
25%
25%
20%

20%
20%
20%
25%

25%

-
20%

20%

20%
25%
25%
25%

25%
25%
20%
25%»l>; GERM ,-,

25%
20%

-

-

-

-

-

-

20%
20%
20%
20%

20%

GERM
GERM
GERM
GERM

ESTM
GERM ,
GERM r!
GERM

GERM -.tv
GERM
GERM
GERM r.

ff/ija

GERM
GERM
GERM
GERM

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L

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^

ALME -

j, ALME ' -

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ALME

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fc , ALME „ - -

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.•:,

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.

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Part No.

.

r

241944700 ,, ,
241314700 (,*

241321500. [y

241314700

225463300 r ..
241944700,
241944700,
241941000'

.0

_ v;-?

. 24i94iooo:,‘:

,

' 241941000 .wf

241941000 '

v,

241322200. ...

V

r m

241322200.;;,:
241322200
241322200
241941000

241944700 ^

208100207'
241313300
241313300

208700106 ^

241944700 ^

241944700 ....,

241944700

-
241944700

C..1

' 241944700"

241331000

241944700 /;'

.-iV

. 241944700:2

241321000
273392200,.

N

273382200

V

273791000 S
273784700

. 273581000

L-

n

273581000

f

26606

‘ 266061000

iood:;:'

^

,..266061000,.^

266061000,';.

2p845014p;?

'J'.iC .

t*w.v

0072g/1636g

6.5

'\F : CO

PGB 1 (cont

ft ft*

Cgt. Ref

CV1

2-14pF

.)

General Description

PTFE

Solartron

Part No.

290060030

Dl

D2

D3 v '
D4

D5
D6 " V-;

xn

"v

D8 -

P9
Dl0> ;
Dll'
D12

D13
D15
D16
D17

D18
D19 ■
D20
D21

303

WR0 57
SD3
BZY 88

BZY88

WR0 57

IN4577

5.6V Zener 5%

8.2V Zener

5%

CO\ .

d

:

303

303

303

SD3

303

SD3

SD3

IN3595
IN3595

SD3

SD3

IN829A reference 6.2V Zener

SD3

400mtf

400mW

■ -

o

O

300522160
300525770
300522160
300521450

300521330
300525770
300525050
300522160

300522160
300522160

.

300522160
300522160

300522160
300522160
300523590
300523590

300522160
300522160

1

300525400
300522160

D22

D25'

D26

D27

D28
D101
D151

0152

0153
0154

0156
0157

TR1
TR2^

TR3r" '
TR4

f

TR5
TR6 '

TR7
TR8

303
WRO 57
WRO 57

BZY88 20V

SD3
SD3
W04
W04

IN4004
IN4004

BZY88

303

3N163
3N163
3N163

WN1001

WN1001
WN1001

PN4118A
WN1001

Zener

20V Zener 5%

' V ^ 1

5%

r * 1 . 1

Z iZ

Zl

C*

*' C.

* . A • 1 !

400mW

; j-.'3 ('*. , .

;

.

-Ticqte

400mW v?Bhta

. ' Acfv

A5.C

£ -

a

.

•

'

-.7

'3t5.V.'g vpf

£

.3

a;

-

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epz *E

?ic

i

vt:

Vc

\?>

'

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VvIx>

'

^ ' u

^ 3 ■.

3v
V

300522160
300525770
300525770
300523790

300522160
300522160
300524700
300524700

300522070
300522070
300523790
300522160

300554530
300554530
300554530
300555770

300555770
300555770
300555880
300555770

0Q72g/1636g

PCB 1

Get.

TR9
TRIO
TR11

TR12

(cont.

Ref.

)

WN1001
U1897
BCY70
WN

1001

General Description

I SD3

Solartron
Part No. ,

sziO

300555770

300553800.

vu

300553590

300555770 ifl

TR13
TR14
TR101

IC1
IC2
IC3

IC4

ICS
IC6
IC7
IC

8

ICQ
IC10
IC11
IC12

IC13

IC14
IC15
IC16

WD460
BC183
BC183

0PL4

DG211
AD545K
0P05

DG211

0P14
DG211
0P05

LM3I1
LM311
74LS175
LM399

ULN2003

LM339
AD528J
DG200

*■'

‘
Op. Amp (matched with IC6)
Quad

analog

SPST switch
Precision FET Op. Amp
Op Amp

Quad Analog SPST switch
Op. Amp (matched

with IC1)
Quad Analog SPST switch
Op Amp

Voltage

Comparator
Voltage Comparator
Quad D-type Flip-Flop
Quad O/Collector

Comparator

7-Channel Buffer

Quad O/Collector Comparator

FET Op. Amp

Dual Analog Switch

VS

300555820 Sd

1

300555590 ud
300555590

c

dd

rs 510091360 dG

510091180 fd

510090741 80

510091130

-L
5100911800 Id
510091360
510091180

510091130

510091280-
510091280-;

in

3

510003170 if:

510090490

510004980 ■ J

510090490 iG

510090380-

c

510091170

IC17
IC18
IC19
IC102

IC103
IC104
IC105
IC106

IC107
IC108
IC151
IC152

IC153

IC154
IC155
IC157

SGI

74LS00
DG211
AD637K
74LS04

Quad

Dual I/P

Quad Analog

Nand Gate

SPST switch
Rms to dc Converter
Hex Inverters

HD68P01V05 Microprocessor

6.8k$2

Resistor pack
NC7033
NC7033

4040 BE
74LS197
7515CKC
LM340T5

79L05ACZ
7915
79L05ACZ
TIL117

12

stage ripple counter

4 bit binary bounter

15V

5V

5V

15V

5V

0.5A pos. volt reg.

0.5A pos. volt reg.

0.1A neg. volt reg.

0.5A neg. volt reg.

0.1A neg. volt reg.

Opto transistor 300540240

Ceramic surge voltage protector, 1400V

510002000 -c!

V-.V

510091460

510091460

g

g

510002690

510006250

160400569

g

510005150 :c
510005150

' 510001820 id

t

-

510005750

;a
510090320 id
510090500

51009095QL3

51009033bn-n

rr 510090950^•

: i? 30001147^-1

ji'".r-

\g

‘

’.

’

0072g/1636g

6.7

"J&

PCS 1

(cont.)

Cctf Rofi

j/

FH1

f

PHI 51

X101

• - - i

,

20mm x

5mm

Fuseholder

20mm x 5m 2A

8-way header,

Fuse

C General Description

0.1" pitch

4.9152MHz crystal. 30pF 0.01%

.

V- " '

*.

S' ;:j. » ; f i

'VeV

Solartron

Part No.
360206040

a

r-s i

360106150

352308060

300810590

TPl
TP2
TP4

OJO:.

T*\ ^
W ‘

VI

?

p

•Vr

Test hook
Test hook
Test hook

;

r>'

r ‘

t*' * r

< - •

355400760
355400760
355400760

:

i-C*

.

;;

* ' . U

nd,'

r'i

C*D

0072g/1636g

.

,•

} »• < r sw1' ■ ‘ "i

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^

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1 :

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1

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^ sf:*:;}ty

V,

Vs..

6.8

2Zf-

5frLl-

f

£35

Get. Ref

SK201
SK202

SK203

Auxiliary

Socket (with ribbon)

GPEB Socket

CAL Socket

Fuse, 2A Fast blow
Fuse, 250mA slow blow
Fuse, 100mA

slow blow

General Description

*-■

fi

-/'j::

a

"-

M

um

SOI

f '-'S.

•p

/'f'v

‘a: :

Vc- „ V
wes.'i

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seefr-SBoegn .

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sr.: ' ; ,

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,:

i0c<5/

Solartrpn
Part N6.
71510205B

352524320.^>

352501740

360106150 iV,

_360106260

o-;:

f1

x

;

a-: /’

'u, '. sj

:

sj

:•=- ' 1

riM

rein

30 5^1

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loca
mo
iOCQ
POLO

1008:'

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vOtOl

;0£D1

rno?7.

nr :

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■ y> v’

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rvv • twe

2L<0^fibj Jeo-:!11! •. - 5<5 ^698

]r-;<v05 iKiKiJ b&a

mm!> ;

tf.'S

: ro-?

' ‘^“Oo

: J' "uqni ir.’.sh

wj-.' rrs-^iC

rn'O1’

wr

ilyX

r-.f. ? .<■

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iasK

0072g/1636g

3Sf.r

'Op.P--;?

.q

6.13

Rnir

::A:-.pn'oo

{

I

(

{

1

PGB 2 (71510502)

Get. Ref.

R201
R202
R203
R204

R205
R206
R208
R209

R211
R212
R213
R214

3.3k
Ik
Ik

220

220
Ik
150k

4.7m

470
15k
12k
12k

0.25W

0.25W

0.25W

0.25W

0.25W

0.25W

0.25W

0.25V

0.25W

0.25W

0.25W

0.25V

. General Description

5%

5%
5%
5%

5%
5%
5%
10%

5%
5%
5%
5%

MEOX
MEOX
MEOX
MEOX

MEOX r .
MEOX "q‘

MEOX
CACP

MEOX
MEOX
MEOX
MEOX

: -195631000

J'OO.I

.hOOfj

‘ -

.r^yL

Solattron
Part No.

195633300

195631000 ’ H'H
195631000
195622200

: MS

195622200

195651000
172064700 V?'l

195624700^'^'

-'IX

i'r

’

195641500
195641200
195641200

R215
R216
R217
R218

R219
R220
R221
R222

R223

R224
R225
R227

R228
R229

R230
R231

R232

R233
R234
R235

270
Ik

6.8k
68k

33k
18k

3.3k

1.5k

3.3k
3k

2.2k

2.2k

6.8k
68k

6.8k
Ik

Ik
1M

6.8k

6.8k

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.25V

0.5V

0.25V

0.25V

5%
5%
5%
5%

5%
5%
5%
5%

5%
5%
5%
5%

5%
5%
5%
5%

5%
5%
5%
5%

MEOX
MEOX
MEOX
MEOX

MEOX
MEOX
MEOX
MEOX

MEOX
MEOX
MEOX

MEOX

MEOX
MEOX
MEOX
MEOX

MEOX

MEOX
MEOX
MEOX

195622700
195631000
195636800
195646800

195643300
195641800
195633300
195631500

195633300
195633000
195632200
195632200

195636800
195646800
195636800

195631000

195631000
193561000
195636800
195636800

R251

C201

1M (on

47nF

through

C215

0216 33pF

C217
C218
C219
0220

0072g/1636g

2-27pF
33pF
33pF
33pF

rear panel)

40V

500V

(variable)

500V
500V
500V

20%

film

20%
20%
20%

25%

GERM

GERM

GERM
GERM
GERM

6.9

172361000

241944700

241313300

290030280
241313300
241313300
241313300

BCB 2

Get, Bef. -

C221 -

C222
0222

C224

(cont)

asr-zx-.

InF
47nF
47nF

lOnF

O' ?
C225'
C226

C227.v\
0228

0229 ?
0230

0232.r ..
0235

0236

0237
0238
0239

l.OnF
lOOuF

47nF

lOOnF

47nF
47nF

,.47nF

47nF

47nF
InF

InF
InF

.> .v

0240

C2Si
0252 .

C253

100pF

2200yF

,2200yF

470yF

'v‘'. •

0254

'if-

D2Qi^;

D202
D263
D204 ,

D205

D206
D207
D208

470yF

v

1N6263

1N6263
1N6263
1N6263

1N825

4.7V Zener

4.7V Zener

SD3

sr-.-ip. • , „

General Description

Solartron
Part No.
241331000

500V
25V
25V

100V

100V
10V
25V
50V

40V
40V
40V
40V

40V
500V
500V
500V

20%
25%
25%

10%

10%
20%
25%
20%

25%
25%

25%

■V-‘‘ .

25%
20%,
20%
20%

UhKM

.

/

■■ tr-**^,*

CERH

GERM

>•-?

ESTF

<’>-• l} -f

ESTF^.;,.
TAND 4,^, tsIWC* W'

GERM (multilayer)

: •“i ; ."r

OERM

^ r

j g- . ^

GERM

CERM

ir

GERM

CERM j,;, ^
GERM

-r, - ^

GERM '

;>#•

^

,•< r*- -« ?•••• i

jjx- 5

g,

.i

-

U':

iVi'

refi

241944700
241944700
227041000

227041000
265481000
241944700
208450140

241944700
241944700
241944700
241944700

.

241944700
241331000

241331000

241331000

■' ! ;;
500V
16V
16V

40V

40V

20%

CERM

■
ALME - ■;
ALME . i - f .
ALME

^ .. << . . .

~}i

* iA-iv «v

-

i J »'''

ALME

: .

i

241321000:
273392200
273392200

273784700

273784700

300525650
300525650
300525650

“i.
> v

-V- ,

■■

■ 'J #'•

.Oi--'

?

Ai,C'

-1

-

-f

V

V£.

‘

;;

'i- .

300525650

300523050
300521470
300521470
300522160

D251
D252

SW201

BAT201

X201
X202

X203

PH201
PH202

TPl->7

0072g/1636g

W0 4
W04

Bridge
Bridge

Rectifier

Rectifier

8-way Interface configuring switch

3.6V Battery

4.9152MHz Crystal

1.8432MHz Crystal

32.768kHz Crystal

4-way Header
2-way Header

Test Hook

6.10

300524700
300524700

375000600

800400210

300810590
300810460
300810640

352304080
352302080

355400760

PGB 2 (cont)

Get. Ref.

IC201
IC202
IC203
IC204

MC3447

MC3447
MC68488
SYP6551A

General Description

,Z

'

8 way trance!vers

8 way trance!vers
GPIB Interface adaptor ^
EiS232 interface^

:'1'

•v.-o'. £ £>£

Solart ton
Part‘No.^idb

510005700

’

510005700

^

510006090&t'

IC205
IC206
IC208

IC209

IC210
IC211
IC212
IC213

IC214
IC215

IC216
IC217

IC218
IC219
IC220
IC221

IC222
IC223
IC224
IC223

IC226
IC227
IC251
IC252

IC253

AD558
HD146818
HM6264P15
74LS139

74LS374
74LS373

HD6303

74LS145

HCPL2601
HCPL2601
MC14040B

74LS197

SN75150

SN75152
LM339
MC14071B

74LS00
74LS04
74LS03

MC14068B

6.8k
100k
LM240T5
78L12

79L12

8 bit digital to analog converter ^
Real time clock" ;

64k static RAM
2 to 4 line decoder

■/; *• ;: v

Octal latch/Flip-flop
Octal tri-state”

[ 1

/>-^5$

latch

’

’

'pi

^

i/d?

8-bit microprocessor ^"{*

BCD to decimal decoder/tiriver V^#v

w *" • 1

Opto-coupled transistor
Opto-coupled transistof 3

12

-stage ripple counter J,

4-bit binary counter

EtS232 line

driver

RS232 line receiver
Quad

0/Collector comparator

Quad dual i/p

Quad

dual i/p Nand Gate
Hex inverters
Quad

dual i/p Nand gate

8-input Nand

Resistor pack

OR gate

gate

s. v<

X Vt*

■■■

’

3'*

v:

''Cf1?

!

'1

-

Resistor pack
5V
12V

12V

0.5A

0.1A

0.1A

pos. volt
pos. volt

neg. volt

reg.
reg.

reg.

510091430

“

510006300^3

v- 510006500.^

v 51000296(FtO

*rC "

510004390

'‘•51000487&£v

9/r

S'5M004990LS2$
*9.' "t

300540260
300540260'
510001820:\t'

510005750.’^

510005250

‘

'51009049DUK-

51000168»$i>

V;"

'

510002000

' - 510002690?^

510004140
510002630r>;C

(ri." r'.

• 16040056957
. 160400598

510090500

510090450x3

iwv-5 V

‘,,'51009046»;f5

i t

'&&&

■

5

“

’

>

0072g/1636g

■ \ i

Vv

*

6.11

M.

V ~ '

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r:? ■ <■

J \1 ? ^

Y'ji-j:, .

.r‘‘

5vin r'-B1- .

,

■?1

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■?

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- -x

a

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V5?;x

5651$

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n

iOShyl

’“'■i'-.T

PCS 3 (71510503) Display Board

Gct.ncRef

R3oi:f

• '' '

,0

180k

R302"; "x1.8k

560

R303
R304 • •'

,v

R305 ;t • '

R307

R308

RV301

C301
C302

D301
D302
D303
D304

270

270
560
47

2k

O.lyF
O.lwF

LED, HP5082-4558
LED, HP5082-4558
LED, HP5082-4558
LED, HP5082-4558

light guide for D30H304

TR301

BCY70

!

\

General Description

Solartron
Part No.

0.25W

0.25W

0.25W

0.25W

0.25W

0.25W

0.25W

0.5W

50V

50V

5%
5%
5%
5%

5%
5%
5%

10%

20%
20%

MEOX 1* •'-■'w)
MEOX
MEOX
MEOX

MEOX

v.ffjrOOi

MEOX
MEOX

multiturn preset

GERM
GERM

:■

,'iC' Vi'1" I :

V36

is/-.

"s'-

L>

'lHC'7.r

195651800
195631800
195625600
195622700

195622700
195625600
195614700

130632000

208450140
208450140

300750270
300750270

300750270

300750270

71502035B

300553590

IC301
XC302

IC303

KB301

X301

NEC7225G
74LS145
316B 6.8k Resistor pack

Keyboard

Matrix (with ribbon)

Liquid Crystal Display

Front Panel

Red 4mm socket
Black 4mm socket
Green 4mm socket

Brown 4mm socket

Front/Rear switch

Rear Panel & Miscellaneous

Red 4mm socket

Black 4mm socket

Green 4mm socket
Yellow 4nm socket

N251

3251

Mains input unit

Mains switch

510005890
510004990

192136800

71512000

352501470
352501480
352501490
352501750
71517001

352501470
352501480
352501490

550001480

375500020

T251

0p72g/1636g

Mains Transformer

309618901

': ’5 6.12

016 R37-

MOS-AVOID STATIC

K TR6

‘mo'.

;

f-2 ans?

1P4

BLUE

0P3 BLACK

YELLOW '

DP5

OREEN

v

5

'<

> V -

V

CI0 7

C10I

IC

103 IN SK

ir ICS

RIOS

RIOI o |

103

R 103

IC

102

IC

105 IC

SOLARTRON

I C

104

106

sp,

IC 108

TPI .

IC

RIM

0157

107

ICI57

LD

o o o

^PS

'

brown

'IV ?

"l (

O'.

;■

‘

L

ly.

i

i

ff!

PCB 1 COMPONENT LAYOUT

FIG 6.1

IC224

TP7 TPS

EFTXEFRX

— in ------------------------------

C220 dp

C2I9

IC203

—

PCB 2 COMPONENT LAYOUT

FIG 6.2

i

oca

zocai

*

PCB 3 COMPONENT LAYOUT

FIG 6.3