Ohmeda 3000 User manual

EDB/

ECI

Infant

Warmer

Systems

Model

3000

and

3300

Service

Manual

BOC

Health

Care

Ohmeda

Service

Manual

Infant

Warmer

System

Model

3000

and

3300

Copyright

1986

Ohmeda

This

document

is

not

to

be

reproduced

in

any

manner,

nor

are

the

contents

herein

to

be

disclosed

to

anyone,

without

the

express

authorization

of

the

_Service

Department,

Ohmeda,

Madison,

Wisconsin.

Table

of

Contents

Εις

ιο

ee

eee

ee

eee

Technical

Competence

.

5/Disassembiy

and

Repair

_..................

5.1

Heater

Module

Repairs

........

…

Repair

Policy

.....................44........

A.

Heater

Housing

Disassembly

...

..

Precautions

iv

B.

Heater

Replacement

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

Torres

assesses

cee

secs sess

teres

C.

Heater

Housing

Assembly

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

1/Functional

Description

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

1-1

D.

Alarm

Lamp

Replacement

........

A.

Power

Supply

Board

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

1-1

E.

Examination

Lamp

Replacement

.. ..

B.

Control

Board

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

1-2 5.2

Control

Module

Repairs

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

C.

Display

Board

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

1-8

A.

Control

Module

Removal

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

B.

Control

Board

and

Power

Supply

Board

2/Specifications

に

で

に

た

と

ただ

とまとすすま

たま

と

た

まま

2-1

Replacement

..

ον

εντ

νωνν

ενω

κε

ων

εως

2.1

Electrical...

-.

24

C.

Display

Module

Disassembly

2.2

Controller

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

2-1

D.

Display

Module

Assembly

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

2.3

Alarms

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

2-1

E.

Control

Module

Replacement

...

2.4

Environmental

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

2-2

F.

Battery

Replacement

.........

2.5

Mechanical

(without

accessories)

22

G.

Circuit

Breaker

Reset

..

2.8

Accessories

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

2-2

5.3

Bed

Platform

Repairs

....

3/Setup

and

Checkout

Procedure

....

.

34

A.

Side

Panel

Replacement.

3.1

Setup......................

...

34

3.

Side

Panel

Repairs

.......

3.2

Checkout

Procedure

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

34

5

Bed

Flatform

Disassembly

-

i .

Be

form

Asse

yo...

μα

B.

Control

Unit

Checks

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

31

,F.

Hydraulic

System

Installation

5.4

Caster

Replacement

................-..

5-16

4/Calibration

and

Adjustments

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

4-1

5.5

Yoke

Manifold

Repairs

...:.............

5-16

A.

Control

Unit

Access

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

.

41

A.

General

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

5-16

B.

Power

Supply

Board

Voltage

Checks

...

4-1

B.

Gauge

Replacement

.....

5-16

C.

Display

Brightness

Check

...........

.

4-1

C.

Gauge

Lens

Replacement

.

5-16

D.

Alarm

Volume

Adjustment

......

.

41

D.

Strainer

Replacement

.....

5-19

E.

Analog

to

Digital

Converter

(ADC)

.

41

E.

Check

Valve

Replacement

.....

5-19

F.

Line

Voltage Sensing

...........

4-2

F.

High

Pressure

Regulator

Repair

.

5-19

G.

Triac

Safety

Circuit

Test

.

42

G.

Pneumatic

Troubleshocting

...

5-20

H.

Test

Loop

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

4-3

。

.

L

Oxygen

Regulator

Check

and

Adjustment

.

4-3

6/Control

Unit

Troubleshooting

Guide

....

.

6-1

y.

Electrical

Safety

Check

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

7/Illustrated

Parts

and

Parts

List

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

71

K.

Ground

Resistance

Check

...

L.

Leakage

Current

Tests

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

8/Schematics

and

Wiring

Diagrams

...........

31

Appendix..................

„A1

A.

Test

Eguipment

and

Special

Tools.

.

А-1

B.

Temperature

Conversion

Chart

.....

.

A-1

C.

Patient

Probe

Characteristics

..

-

A-1

D.

Drawer

Kit

Accessory

.......

..

A2

E.

O2

Yoke

and

Regulator

Assembly

Kit

......

A3

Important

The

information

contained

in

this

service

manual

pertains

only

to

those

models

of

products

which

are

marketed

by

Ohmeda

as

of

the

effective

date

of

this

manual

or

the

latest

revision

thereof.

This

manual

‘was

prepared

for

exclusive

use

by

Ohmeda

service

personnel

in

light

of

their

training

and

experience

and

the

availability

to

them

of

proper

tcols

and

test

equipment.

Consequently,

Ohmeda

provides

this

manual

to

its

customers

purely

as

a

business

con-

venience

and

for

the

customer's

general

information

only

without

warranty

of

the

results

with

respect

to

any

application

of

such

information.

Furthermore,

because

of

the

wide

variety

of

circumstances

under

which

maintenance

and

repair

activities

may

be

per-

formed

and

the

unique

nature

of

each

individuals

own

experience,

capacity,

and

qualifications,

the

fact

that

customer

has

received

said

information

from

Ohmeda

does

not

imply

in

any

way

that

Ohmeda

deems

said

individual

to

be

qualified

to

perform

any

such

maintenance

or

repair

service.

Moreover,

it

should

not

be

assumed

that

every

ac-

ceptable

test

and

safety

procedure

or

method,

pre-

caution,

tool,

equipment

or

device

is

referred

to

within,

or

that

abnormal

or

unusual

circumstances

may

not

warrant

or

suggest

different

or

additional

procedures

or

requirements.

This

manual

is

subject

to

periodic

review

and

cus-

tomers

are

cautioned

to

obtain

and

consult

the

latest

revision

thereof

and

suggestions

are

invited

from

our

customers

for

consideration

by

Ohmeda

with

these

periodic

reviews.

WARNING:

After

completing

a

repair

of

the

Infant

Warmer

System

the

appropriate

calibration

proce-

dure

must

be

performed

to

make

sure

the

Infant

Warmer

System

is

in

proper

operating

condition.

In

addition

a

final

electrical

safety

check

and

leak-

age

current

test

must

be

performed.

Record

the

in-

formation

for

future

reference.

WARNING:

After

completing

any

portion

of

the

calibration

and

adjustments

procedure

for

the

In-

fant

Warmer

System

the

checkout

procedure

must

be

performed

to

make

sure

the

Infant

Warmer

System

is

in

proper

operating

condition.

In

addi-

tion

a

final

electrical

safety

check

and

leakage

cur-

rent

test

must

be

performed. Record

the

informa-

tion

for

future

reference.

CAUTION:

Servicing

of

this

product

in

accordance

with

this

service

manual

should

never

be

underta-

ken

in

the

absence

of

proper

tools,

test

equipment

and

the

most

recent

revision

of

this

service

man-

ual

which

is

clearly

and

thoroughly

understood.

This

static

control

precaution

symbol

appears

throughout

this

manual.

When

this

symbol

ap-

pears

a

procedure

in

this

manual,

static

control

precautions

must

be

observed.

Use

the

static

control

work

station

(Part

No.

0175-2311-

000)

to

help

ensure

that

static

charges

are

safely

conducted

to

ground

and

not

through

sta-

tic

sensitive

devices.

This

document

is

not

to

be

reproduced

in

any

man-

ner,

nor

are

the

contents

herein

to

be

disclosed

to

anyone, without

the

express

authorization

of

the

Ohmeda

Product

Service

Department,

Madison,

Wis-

consin.

iii

Repair

Policy

and

Procedure

Note:

Service

must

be

performed

by

a

“Technically

Competent”

individual.

Do

not

use

malfunctioning

equipment.

Make

all

nec-

essary

repairs,

or

have

the

equipment

serviced

by

an

Authorized

Ohmeda

Service

Representative.

After

repair

test

the

equipment

to

ensure

that

it

is

functioning

properly,

in

accordance

with

the

man-

ufacturer's

published

specifications.

To

ensure

full

reliability,

have

all

repairs

and

service

done

by

an

authorized

Ohmeda

Service

Representa-

tive.

If

this

cannot

be

done,

replacement

and

maintenance

of

those

parts

listed

in

this

manual

may

be

undertaken

by

a

competent,

trained

indi-

vidual

having

experience

in

the

repair

of

this

type

of

equipment.

CAUTION:

No

repair

should

ever

be

undertaken

or

attempted

by

anyone

not

having

such

qualifica-

tions.

Replace

damaged

parts

with

components

manufac-

tured

or

sold

by

Ohmeda.

Then

test

the

unit

to

as-

certain

that

it

complies

with

the

manufacturer's

published

specifications.

Contact

the

nearest

Ohmeda

service

office

for

ser-

vice

assistance.

If

you

send

the

unit

to

the

Ohmeda

Service

Center,

package

it

securely

in

the

original

shipping

container,

if

possible,

and

ship

it

prepaid.

Enclose

a

letter

with

the

unit

describing

in

detail

any

difficulties

experienced

and

the

repairs

felt

nec-

essary.

In

all

cases,

other

than

where

Ohmeda's

warranty

is

applicable,

repairs

will

be

made

at

Ohmeda's

current

list

price

for

the

replacement

part(s)

plus

a

reasonable

labor

charge.

CAUTION:

Detailed

drawings

and

procedures

for

more

extensive

repairs

are

included

herein

solely

for

the

convenience

of

users

having

proper

knowl-

edge,

tools,

and

test

equipment,

and

for

service

representatives

specially

trained

by

Ohmeda.

Technical

Competence

The

procedures

described

in

this

service

manual

should

be

performed

by

trained

and

authorized

per-

sonnel

only.

Maintenance

should

only

be

underta-

ken

by

competent

individuals

who

have

a

general

knowledge

of

and

experience

with

devices

of

this

nature.

Genuine

replacement

parts

manufactured

or

sold

by

Ohmeda

must

be

used

for

all

repairs.

Read

completely

through

each

step

in

every

proce-

dure

before

starting

the

procedure;

any

exceptions

may

result

in

a

failure

to

properly

and

safely

com-

plete

the

attempted

procedure.

Copyright

1986

by

Ohmeda,

Ohmeda

Drive,

Madi-

son,

Wisconsin

53707-7550.

Precautions

Warnings

After

completing

a

repair

of

the

Infant

Warmer

Sys-

tem

the

appropriate

calibration

procedure must

be

performed

to

make

sure

the

Infant

Warmer

System

is

in

proper

operating

condition.

In

addition

a

final

electrical

safety

check

and

leakage

current

test

must

be

performed.

Record

the

information

for

fu-

ture

reference.

After

completing

any portion

of

the

calibration

and

adjustments

procedure

for

the

Infant

Warmer

Sys-

tem

the

checkout

procedure

must

be

performed

to

make

sure

the

Infant

Warmer

System

is

in

proper

operating

condition.

In

addition

a

final

electrical

safety

check

and

leakage

current

test

must

be

per-

formed.

Record

the

information

for

future

reference.

Overloading

the

shelves

can

affect

the

stability

of

the

unit.

Do

not

perform

the

Check-Out

Procedure

while

a

patient

occupies

the

Infant

Warmer

System.

Never

oil

or

grease

oxygen

equipment

unless

a

lu-

bricant

that

is

made

and

approved

for

this

type

of

service

is

used.

Oils

and grease

oxidize

readily,

and

in

the

presence

of

oxygen,

will

burn

violently.

Vac

Kote*

is

the

oxygen

service

lubricant

recommended

(Order

No.

0220-0091-300).

When

replacing

gauges,

be

sure

to

use identical

pressure

ranges.

Do

not

use

oil

or

oil

bearing

materials

on

or

near

the

regulator.

Oils

and

greases

oxidize

readily

and,

in

the

presence

of

oxygen,

they

will

burn

violently.

All

metallic

parts

of

the

regulator

must

be

discarded

if

contaminated

with

oil

or

grease.

*

Vac

Kote

is

a

trademark

of

the

Ball

Corporation.

Cautions

Servicing

of

this

product

in

accordance

with

this

service

manual

should

never

be

undertaken

in

the

absence

of

proper

tools,

test

equipment

and

the

most

recent

revision

of

this

service

manual

which

is

clearly

and

thoroughly

understood.

This

static

control

precaution

symbol

appears

throughout

this

manual.

When

this

symbol

ap-

pears

a

procedure

in

this

manual,

static

control

precautions

must

be

observed.

Use

the

static

control

work

station

(Part

No.

0175-2311-

000)

to

help

ensure

that

static

charges

are

safely

conducted

to

ground

and

not

through

sta-

tic

sensitive

devices.

No

repair

should

ever

be

undertaken

or

attempted

by

anyone

not

having

such

qualifications.

Detailed

drawings

and

procedures

for

more

exten-

sive

repairs

are

included

herein

solely

for

the

con-

venience

of

users

having

proper

knowledge,

tools,

and

test

equipment,

and

for

service

representatives

specially

trained

by

Ohmeda.

For

the

Model

3000

Infant

Warmer

System

the

height

of

the

bed

should

be

27

inches

+2

inches

from

the

bottom

of

the

heater

module

for

proper

heating

and

temperature

control.

Insulation

on

electrical

wiring

can

deteriorate

with

age.

Check

for

brittle

or

deteriorated

insulation

on

power

cord

and

all

other

electrical

wiring.

Use

the

Static

Control

Work

Station

(Part

No.

0175-

2311-000)

to

help

ensure

that

static

charges

are

safely

conducted

to

ground.

The

Velostat

material

is

conductive.

Do

not

place

electrically

powered

circuit

boards

on

it.

The

back

panel

and

display

panel

may

drop

down

when

the

bottom

cover

mounting

screws

are

re-

moved.

Be sure

to

secure

the

panels

with

tape

be-

fore

disassembly.

Disconnect

the

Infant

Warmer

System

power

cord

and

allow

the

unit

to

cool

before

replacing

the

examination

or

alarm

light.

Disconnect

the

Infant

Warmer

System

power

cord

and

allow

the

unit

to

cool

before

replacing

the

examination

light.

The

lamp

normally

operates

at

a

high

temperature.

Take

static

precautions

for

these

procedures.

For

safety

have

at

least

2

people

available

to

re-

place

a

caster.

Remove

all

accessory

equipment.

iv

1/Functional

Description

A.

Power

Supply

Board

This

is

a

functional

description

for

the

Infant

Warmer

System

Power

Supply

Board

Part

No.

0631-

5032-700.

Réfer

to

Schematic

No.

0676-0327-000

for

a

detailed

circuit

diagram.

The

power

supply

board

contains

circuitry

for

the

control

and

monitoring

of

voltage

devices.

The

board

also

provides

power

to

the

control

board

and

the

display

board.

Also

found

on

the

board

is

a

line

voltage

sensing

circuit

that

provides

an

indication

of

line

voltage

to

the

microcontroller.

.

The

control

circuits

for

each

line

voltage

device

on

the

power

supply

board

are

functionally

identical

with

a

logic

“High”

signal

from

the

control

board

switching

"On”

the

desired

device.

This

is

per-

formed

with

an

opto-isolator

triac

driver

so

low/line

voltage

circuits

can

interact

but

remain

electrically

isolated

(2500

volt

dielectric).

The

heater

is

controlled

from

the

supply

board

with

an

opto-isolator

triac

driver

and

triac.

There

is

also

a

relay

contact

connected

in

series

with

the

neutral

to

the

heater

triac.

This

is

used

to

switch

“Off"

the

heater

if

the

heater

triac

fails

or

there

is

a

failure

on

the

control

board.

The

regulator

circuits

provide

a

+5

Vdc

supply

to

the

display

board

and

+5

Vdc,

and

+9

Vdc,

supplies

to

the

control

board.

A

ni-cad

battery

supplies

the

§

Vdc

supply

and

a

de-rated

9

Vdc

sup-

ply

for

standby

power,

in

the

case

of

a

power

loss.

Standby

power

of

9

volts

is

used

to

activate

the

transducer

alarm,

while

the

5

volt

supply

provides

power

to

the

microcontroller

and

associated

IC's

for

memory

retention

purposes.

5

Volt

LEDS

A

nominal

8

Vac

is

input

to

the

power

supply

board

at

J11

pins

3

and

4.

The

line

frequency

is

also

con-

nected

to

the

control

board

via

J12

2.

The

bridge

rectifier

CR2

and

capacitor

C11

provide

a fil-

tered

unregulated

8

Vdc

to

the

relay,

opto-isolators,

and

the

regulator

VR12.

The

8

Vdc

unregulated

sup-

ply

can

be

measured

at

TP-1.

The

unregulated

sup-

ply

must

be

a

minimum

of

7.32

volts

for

proper

op-

eration

of

the

relay

circuit.

The

output

of

regulator

VR2

is

nominally

+5

Vde

and

supplies

power

to

drive

the

LED

displays

on

the

display

board.

The output

is

measurable

at

J12

12

(TP-10).

When

the

supply

voltage

is

within

10%

of

nominal,

the

output

voltage

should

be

between

4.8

and

5.2

volts

dc

with

a

maximum

load

of

500

ma.

The

maximum

allowable

ripple

voltage

is

150

millivolts.

Line

Voltage

Sensing

A

voltage

of

approximately

11

Vac

from

the

trans-

former

secondary

is

input

to

the

board

at

J11

pins

1

and

2.

Bridge

rectifier

CR1

and

capacitor

C12

pro-

vide

a

full

wave,

filtered

voltage

of

approximately

12

Vdc.

Resistor

R3

is

preset

to

produce

an

output

of

approximately

0.6

volts

at

J12

11

(TP-11)

when

the

line

voltage

is

at

the

nominal

value

for

the

unit.

The

analog

voltage

signal

at

J12

11

connects

to

the

control

board

and

is

fed

into

the

A/D

Converter,

ADC

3711

(U6),

via

the

multiplexer,

MC14051B

(U-

13).

The

digital

output

of

the

A/D

converter

is

input

to

the

microcontroller

where

the

software

then

ad-

justs

the

power

to

the

heater

to

compensate

for

var-

iations

in

line

voltage.

9

Volt

Standby

The

output

of

regulator

VR3

is

adjusted

by

R4

to

provide

9.0

+

0.2

volts

(TP12).

This

voltage

is

used

for

charging

the

NI-CAD

battery,

and

supplying

the

input

voltage

to

the

+5

standby

regulator.

5

Volt

Standby

When

line

voltage

is

available,

current

flows

from

the

output

of

VR3

and

through

CR5

to

provide

9.0

+

0.2

volts

to

the

input

of

VR4,

and

to

J12

3

(TP-12).

In

tum,

regulator

VR4

outputs

a

voltage

of

5.0

+

0.2

volts

to

J12

14

(TP-9)

with

a

maximum

ripple

voltage

of

150

millivolts.

If

power

loss

occurs

with

the

unit

switched

ON,

the

7.2

volt

NI-CAD

battery

maintains

a

de-rated

output

voltage

of

approximately

6.5

volts

to

3

of

J12

(TP-12).

It

also

provides

input

to

VR4.

The

output

of

VR4

only

regulates

to

approximately

5.0

volts

as

the

input

voltage

drops

below

7.0

volts.

Observation

Light,

Alarm

Lights,

Motor

Control

The

control

circuits

for

the

observation

light,

and

the

alarm

light

are

similar.

The

alarm

light

is

a

resis-

tive

load

and

does

not

have

a

snubber

circuit

in

parallel

with

the

load.

The

snubber

circuit

on

the

observation

light

supply

protects

the

triac

from

large

voltage

spikes

characteristic

of

inductive

loads.

If

the

control

lines

are

logic

“Low",

less

than

0.45

volts,

this

keeps

the

FET,

triac

driver,

and

triac

switched

“Off”.

The

triac

acts

as

a

switch

to

the

line

voltage

circuit,

removing

voltage

from

the

load.

When

a

device

should

be

switched

“On”,

a

logic

“High”

of

2.4

volts

minimum

is

output

to

the

corres-

ponding

FET.

The

FET

switches

“On”

causing

the

LED

ot

the

isolator-driver

to

switch

on.

The

isolator/

driver

output

drives

sufficient

current

to

the

triac

gate,

switching

the

triac

"On"

allowing

the

selected

device

to

switch

“On”.

Heater

Status

and

Control

The

heater

circuitry

consists

of

a

monitoring

circuit,

a

controller

for

the

heater,

and

à

relay

to

switch

“Off"

the

heater

in

the

event

of

a

triac

or

system

failure.

The

full

wave

bridge

rectifier

CR6

takes

a

sample

(through

R 13)

of

the

ac

signal

supplied

to

the

hea-

ter

and

provides

rectified

dc

to

the

opto-isolator

U3.

If

the

heater

is

“On”

the

de

output

switches

“On”

the

LED

in

the

opto-isolator,

except

at

voltage

levels

below

the

forward

bias

voltage.

When

the

LED

is

“On”

the

transistor

goes

into

saturation

causing

the

output

at

J12

1

to

go

“Low”

(about

0.3

volts).

When

the

heater

is

“Off”

the

de

signal

is

in

the

re-

gion

of

zero

potential

and

there

is

insufficient

for-

ward

bias

voltage

for

the

LED.

This

switches

“Off”

the

transistor

allowing

capacitor

C10

to

charge

and

causes

J12

1

to

go

high

(5

volts),

When

the

hea-

ter

is

switched

“On"

the

LED

switches

the

transis-

tor

“On”

again,

and

the

capacitor

discharges.

The

low

output

shows

small

glitches

caused

by

the

charge/discharge

of

the

capacitor

at

every

half

cycle.

The

glitches

are

acceptable

provided

they

do

not

exceed

the

trigger

voltage

of

1.4

volts

for

the

74LS132

on

the

Control

Board.

1-1

1/Functional

Description

The

heater

control

circuit

uses

a

zero

crossing

opto-

isolator

triac

driver

to

isolate the

line

voltage

from

the

low

voltage

circuits.

Operation

of

the

heater

control

and

other

line

voltage

controls

differ

only

in

the

type

of

isolator

used

and

the

use

of

snubber

cir-

cuits.

When

a

logic

“High”

signal

is

sent

to

the

hea-

ter

control

circuit

from

J12 pin

9

the

output

of

the

isolator

will

not

switch

“On”

until

the

ac

signal

of

the

heater

crosses

the

zero

potential

from

a

nega-

tive

voltage.

After

the

input

line

from

the

microcon-

troller

goes

“Low”,

heat

will

not

switch

“Off”

until

the

first

zero

crossing

preceded

by

the

negative

half

cycle.

This

provides

zero

crossing

control

of

the

hea-

ter

switching.

The

time

that

the

heater

is

“On"

de-

pends

on

the

percent

heat

desired

(controllable

in

5%

increments).

The

microcontroller

also

monitors

the

line

voltage

and

adjusts

the

number

of

ac

cycles

that

the

heater

is

switched

“On”.

This

provides

heater

compensa-

tion.

If

the

line

voltage

is

not

at

the

nominal

value

these

two

functions

result

in

60

levels

of

heat.

Relay

The

relay

circuit

is

used

to

switch

“Off"

the

heater

in

the

event

of

a

triac

or

microcontroller

failure.

Under

normal

conditions

the

input

line

from

J12 pin

10

is

a

logic

“High”,

2.4

volts

minimum.

A

logic

"High"

signal

on

the

input

from

the

control

board

switches

“On”

the

FET

causing

the

relay

coil

to

en-

ergize

and

close the

switch.

If

the

FET

input

is

a

“Low”

from

the

control

board,

(0.5

volts

max.)

the

FET

switches

“Off”

and

the

relay

contacts

open.

The

signal

at

J12

10

comes

from

U1

on

the

con-

trol

board

which

is

a

part

of

a

logic/timing

circuit

in-

dependent

of

the

microprocessor.

A

minimum

voltage

of

7.2

volts

is

reguired

to

ener-

gize

the relay

coil.

Therefore

the

minimum

allowable

voltage

for

the

8

volt

unregulated

supply

is

7.32

volts

since

the

FET

has

an

internal

voltage

drop

of

0.12

volts.

B.

Control

Board

This

is

a

functional

description

for

the

Infant

Warmer

System

Control

Board

Part

No.

0631-5033-

700.

Refer

to

Schematic

No.

0676-0326-000

for

a

de-

tailed

circuit

diagram.

The

control

board

contains

electronic

circuitry

invol-

ved

with

the

measurement,

control,

computation,

memory,

logic,

and

decision

making

functions

of

the

Infant

Warming

System.

The

principle

IC

on

this

board

is

the

8031

single

component,

8-bit

microcon-

troller.

The

8031

has:

an

internal

read/write

memory

(RAM)of

128

bytes,

32

I/O lines

configured

as

four

8-

bit

parallel

ports,

two

16-bit

timers,

a

five

source

two

priority

nested

interrupt,

a

programmable

serial

VO

port,

and

an

on-chip

oscillator

with

clock

cir-

cuitry.

The

program

memory

is

stored

in

a

2764

64k

bit

(8k

x

8)

UV

EPROM.

An

octal

transparent

latch

(74LS373)

is

connected

to

address

inputs

of

the

EPROM

to

permit

the

use

of

the

bi-directional

data

bus

port

of

the

microcontroller

for

addressing

the

EPROM

and receiving

program

instructions.

Four

ICs

with

a

network

of

precision

resistors

are

used

to

interface

the

microcontroller.

The

tempera-

ture

sensor,

calibration

resistors,

or

line

voltage

1-2

scaler

are

selected

by

an

MC14051B

8

Channel

Mul-

tiplexer.

An

LM-10

precision

reference

with

adjusta-

ble

reference

buffer,

and

on-board

operational

amplifier

furnishes

a

stable

reference

supply.

This

is

reguired

by

the

temperature

measurement

circuits

and

the

ADC

3711

Analog

to

Digital

Converter.

An

8243

I/O

expander

is

used

to

interface

the

microcon-

troller

with

the

multiplexer

and

the

A/D

converter.

The

control

board

is

also

equipped

with

several

IC's

that

form

the

triac

watchdog

circuit,

watch-dog

timer,

and

the

audio

alarm

tone

generator.

The

audio

transducer

for

the

alarm

signals

and

its

driver

circuit

are

also

included

on

the

control

board.

The

operation

of

the

circuits

listed

in

the

preceding

paragraphs

will

be

explained

in

detail

below.

Analog

to

Digital

Converter

Temperatures

are

measured

using

a

negative

tem-

perature

coefficient

thermistor

that

is

calibrated

for

specific

resistance

values

and

interchangeability.

Analog

voltage

signals

inversely

proportional

to

temperature

are

derived

from

a

voltage

divider

net-

work

consisting

of

a

5.76k

+

0.1%

resistor

in

series

with

the

temperature

sensor.

The

voltage

source

for

the

measuring

circuit

is

obtained

from

the

LM-10's

internal

precision

reference

source

of

200

mV

amplified

to

a

nominal

1.0

volts

by

the

reference

buffer

of

the

LM-10.

The

Op-amp

portion

of

the

LM-

10

provides

an

adjustable

reference

of

2.0

volts

nominally,

which

is

required

by

the

A/D

converter,

U6.

In

addition

to

the

patient

probe,

there

are

three

other

voltage

divider

networks

on

the

control

board.

Two

have

fixed

output

and

are

used

for

calibration

check

points

of

the

A/D

system

at

25.0

and

37.9

de-

grees

C.

The

third

divider

network

is

unused.

A

separate

input

to

the

control

board

A/D

circuit

comes

from

the

line

voltage

monitor

network

lo-

cated

on

the

power

supply

board.

The

outputs

of

all

the

voltage

dividing

networks

are

connected

to

individual

switch

input

terminals

of

U13,

the

MC14051B

Analog

Multiplexer.

The

MC14051B

contains

eight

normally

open

switches

with

a

common

output

terminal.

The

common

out-

put

of

the

MUX

(pin

3)

is

tied

directly

to

the

analog

input

(pin 9)of

the

A/D

converter.

The

microcontrol-

ler

selects

which

sensor

is

to

be

measured

by

toggl-

ing

the

control

lines,

11A,

10B,

and

9C

of

the

MUX

via

the

8243

#2,

US.

The

following

table

shows

the

digital

codes

used

to

select

the

individual

switches

of

the

MUX:

Control

On

Inputs

Switches

Number

ABC

000

χο

13

calibration

value

25C

001

xt

14

calibration

value

37.9C

010

X2

15

line

voltage

monitor

011

X3

12

unused

100

X4

01

patient

probe

101

X5

05

unused

110

X6

02

unused

111

X7

04

unused

Note:

Inhibit

terminal

(pin

6)

of

the

MUX

has

no

ef-

fect

on

the

switch

selection

because

it

is

tied

"Low"

through

R19

(200

ohms).

1/Functional

Description

The

ADC

3711,

U6,

uses

a

pulse

modulation

analog

to

digital

conversion

technique.

The

conversion

rate

is

set

by

the

frequency

of

an

internal

oscillation

whose

frequency

is

determined

by

the

external

com-

ponents

R4

and

C14.

The

exact

oscillator

frequency

is

not

critical

and

may

vary

by

+

15%

from

the

nominal

400

kHz.

The

oscillator

frequency

may

be

measured

on

18

of

U6.

With

a

nominal

400

kHz

clock

frequency,

conversions

within

the

ADC

3711

will

take

place

at

an

approximate

rate

of

3

per

sec-

ond.

The

ADC

3711

will

output

BCD

data

on

demand

in

accordance

with

the

coded

digital

signals

applied

to

the

digit

select

inputs

DO

and

D1,

pins

20

and

21

re-

spectively.

The

data

latch

enable

is

tied

“Low”,

therefore,

the

BCD

data

of

the

A/D

converter

will

be

output

to

the

microcontroller

through

8243

#2

in

conformance

to

the

following

codes

that

are

applied

to

the

digit

select

inputs:

Do D1

Selected

Digit

L

Digit

0

LSD

L

H

Digit

1

H

L

Digit

2

H

Digit

3

MSD

Note:

The

magnitude

of

the

selected

digit

is

present

at

pins

23

and

24,

The

ADC

3711

is

continuously

converting

the

analog

voltage

present

at

its

input

to

a

number

of

counts

between

0

and

3989

(BCD

format).

Therefore,

the

start

conversion,

input

at

7,

and

the

conversion

complete,

output

at

6,

are

misnomered.

The

start

conversion

input

only

controls

the

transfer

of

information

from

the

internal

counter

to

the digital

latches.

The

conversion

complete

output

goes

to

a

logic

“Low”

on

the

rising

edge

of

the

start

conver-

sion

pulse

which

is

issued

by

the

microcontroller.

The

conversion

complete

will

go

to

a

logic

“High”

sometime

later

when

the

new

conversion

informa-

tion

has

been

transferred

to

the

display

latches.

The

start

conversion

pulse

may

occur

at

any

time

in

the

conversion

cycle

because

the

microcontroller

is

run-

ning

asynchronously

to

the

A/D

clock.

Therefore,

the

amount

of

time

from

the

start

to

finish

will

vary.

The

maximum

time

difference

between

the

start

conversion

and

conversion

complete

pulses

in

this

application

is

about

300

msec.

The

operation

of

the

temperature

and

line

voltage

Measurement

circuits

can

be

summarized

as

fol-

lows:

The analog

voltage

signal

derived

from

a

vol-

tage divider

network

and

a

precision

reference

source

is

directed

to

the

input

of

the

A/D

converter

through

an

eight

channel

analog

multiplexer.

For

the

line

voltage

measurement,

the

voltage

source

is

obtained

from

the

rectified,

filtered,

and

unregulated

output

of

the

power

transformer.

Switch

selection

is

software

controlled

by

the

microcontroller

which

toggles

the

A,

B,

and

C

input

lines

of

the

multi-

plexer.

The

analog

voltage

is

converted

in

the

ADC

3711

to

a

digital

signal

in

four

digit

BCD

format

(0

to

3999

counts).

The

microcontroller sends

a

start

conver-

sion

pulse

to

the

ADC

3711

which

then

starts

to

up-

date

the

digital

data

in

the

output

latches.

When

all

of

the

counts

have

been

internally

transferred,

the

A/D

converter

toggles

the

conversion

complete

out-

put

line.

The

microcontroller

then

reads

the

indi-

vidual

BCD

digits

using

coded

signals

to

the

digit

select

lines

of

the

A/D

converter.

ADC

Calibration

The

A/D

converter

is

calibrated

by

connecting

a

5900

+

0.1%

ohm

resistor

to

the

patient

probe

jack

and

placing

the

DIP

switch

on

the

control

board

in

the

following

position:

Swritch 41

Open

(Off)

Switch

42

Open

(Off)

Switch

#3

Open

(Off)

Switch

#4

Closed

(On}

Potentiometer

R44

on

the

control

board

is

then

ad-

justed

until

the

elapsed

time

display

reads

exactly

1122.

With

the

DIP

switches

in

the

given

position,

the

patient

temperature

display

will

read

out the

ac-

tual

patient

temperature,

even

if it

is

outside

of

the

normal

range

and

the

control

temperature

display

will

read

out

the

percent

of

nominal

line

voltage.

During

operation,

the

calibration

of

the

A/D

conver-

sion

system

may

be

checked

by

pressing

and

hold-

ing the

hidden

switch

located

above

the

alarm

si-

lence

switch

on

the

control

panel.

After

2

seconds,

the

patient

temperature

display

should

read

25.0

and

the

control

temperature

display

should

be

37.9.

The

elapsed

timer

should

read

the

nominal

line

vol-

tage

+

2%.

Microcontroller

The

control

system

is

located

in

the

8031

microcon-

troller.

It

operates

at

a

clock

speed

of

6MHz

and

can

he

verified

by

measuring

the

frequency

at

the

Ad-

dress

Latch

Enable

(ALE)

to

be

1

MHz

("On"

=

0.33

usec

and

“Off”

=

0.67

usec).

Grounding

the

EA

enables

the

8031

to

execute

instructions

from

an

external

memory

device.

When

the

microcontroller

performs

a

read

instruc-

tion

from

EPROM,

the

low

order

address

(8

bits)

is

output

from

Port

0

while

the

high

order

address

(6

bits)

outputs

from

Port

2.

(Note:

Bit

6 is

configured

only

to

provide

expansion

compatibility

with

a

27128

EPROM).

The

ALE

goes

“High”

allowing

the

LS373

to

appear

transparent

between

the

EPROM

and

the

microcontroller.

After

the

ALE

out-

put

goes

“Low”,

the

low

order

address

is

latched

to

the

outputs

of

the

D

flip

flops

within

the

LS373.

This

allows

the

2764

to

remain

addressed

by

the

microcontroller,

and

return

8

bits

of

data

while

using

only

two

ports.

Port

1

of

the

8031

is

used

to

communicate

to

the

three

8243

I/O

expanders.

Bits

5-7

are

connected

to

the

Chip

Select

(CS)

line

of

the

first,

second,

and

third

respective

1/O

expanders.

Providing

a

“Low”

signal

on

one

and

only

one

of

the

outputs

activates

the

corresponding

IC.

Bits

0-3

hold

the

instruction

to

be

carried

out

by an

8243

when

the

enable

bit

4

transitions

between

“High”

and

“Low".

1/Functional

Description

Port

3

is

used

to

perform

remaining

tasks

required

by

the

control

system.

Connections

3.0

and

3.1,

(re-

ceive

and

transmit

respectively),

are

used

in

con-

junction

with

the

serial

interface

chips

so

that

com-

munication

to

an

external

microcomputer

is

possi-

ble.

Connection

INTO/P3.2

is

a

line

frequency

inter-

rupt

line

that

is

used

to

aid

in

timing

subroutines

found

within

the

system

software.

Connection

T0/

P3.4

sends

serial

data

to

the

display

driver

while

connection

T1/P3.5

provides

clocking

to

the

driver.

Line

Frequency

The

line

frequency

circuit

converts

a

60

or

50

Hz

sinusoidal

signal

into

a

square

wave

signal.

The

output

of

the

circuit

is

used

to

clock

the

4020B

counter

and

to

provide

a

low

frequency

clock

source

for

the

system

software.

The

1N4001

diode

haif-

wave

rectifies

the

8

Vac

(nominal)

signal

for

use

with

the

Schmitt

trigger

NAND

gate.

With

one

line

tied

“High”,

the

output

of

the

trigger

will

be

inver-

ted.

Since

the

gate

will

not

respond

until

the

input

exceeds

1.9

volts

minimally,

the

duty

cycle

of

the

output

will

be

slightly

more

than 50%.

Heater

Status

The

Heater

Status

function

signals

the

microcontrol-

ler

and

the

safety.

circuitry

as

to

whether

or

not the

heater

is

“On"

or

“Off”.

The

input

to

the

Schmitt

trigger

is

“High”

if

the

heater

is

“Off”

and

“Low”

if

the

heater

is

“On”.

Small

glitches

appear

when

the

heater

is

“On".

Consult

the

Functional

Description

of

the

power

supply

board

for

further

explanation.

The output

of

the

NAND

gate

is

inverted

because

one

input

is

tied

“High”.

Hardware

Triac

Test

The

4020B

14

bit

binary

counter,

U9,

counts

at

a

rate

equal

to

the

line

frequency

and

responds

to

the

negative

edge

of

the

clock

pulse.

The

clock signal

is

received

from

a

Schmitt

trigger

NAND

gate,

6

of

U8.

The counter

resets

when

the

7418123

retrigger-

able

one

shot

flip

flop

outputs

a

“High”

level

pulse

on

the

O

output

Ime.

With

CLR

tied

“High”

and

A

tied

“Low”,

the

counter

will

reset

when

B

of

the

7418123,

US,

is

“High”

at

a

time

equal

to

(04)

+(013)

+(014)

or

after

12296

counts

(04

=

8,

013

=

4096,

014

=

8192).

Approximately

6.19

usec.

later

the

output

of

the

one shot

will

return

to

its in-

itial

“Low”

state.

Q13

and

Q14

of

the

4020B

are

tied

to

a

2

input

“And”

gate

which

will

go

“High”

after

12288

counts.

On odd

numbered

counts

Q1

of

the

counter

goes

“High”.

Q1

is

tied

to

the

CLR

of

D

flip

flop

Ui,

which

when

“High”

allows

the

output

O

to

equal

the

input

D

on

the

edge

of

the

clock

pulse.

Therefore

the

output

at

5

will

up-

date

on

even

counts.

After

12288

counts

(3.4133

minutes

on

60Hz

units,

or

4.096

minutes

for

50Hz

units)

the

signal

at

the

D

input

of

the

flip

flop

goes

“High”.

This

signal

is

also

input

to

the

microcontrol-

ler

through

the

1/0

expander

U4.

The

software

will

then

switch

“Off”

the

heat.

Two

counts

later

the

“High"

input

on

D

is

clocked

to

the

output

Q.

The

heater

status

(“Off"-“Low",

“On"-“High")

sent

from

the

Schmitt

trigger

NAND

gate

11

of

U8

is

al-

ways

present

at

the

input

of

U2

5. If

the

heater

is

still

“On”

after

the

2

counts,

the

output

of

the

“And”

gate

6

of

U2

will

clock

the

second

D

flip

flop.

The

outputs

of

the

flip

flops

switch

~O

goes

“High”

and

“Not

Q”

goes

“Low”.

A

“Low"

on

“Not

O"

sets

off

the

audio

alarm

and

drops

out the

non-

1-4

resettable

safety

relay

causing

the

heater

to

switch

“off”.

Heater

Status

LED

A

heater

status

LED

is

located

on

the

control

board

for

troubleshooting.

The

LED

can

be

seen

through

the

rear

of

the

controller

assembly

cover.

When

the

status

line

from

the

Schmitt

trigger

is

“High”,

(hea-

ter

“On”)

the

transistor

O2

switches

“On”

causing

the

LED

to

emit

light.

If

heat

is

“Off”,

the

LED

is

“Off”.

Watchdog

Timer

A

watch

dog

timer

is

used

to

“check”

that

the

microcontroller

is

working

properly.

After

every

cycle

through

the

system

software

the

microcontrol-

ler

sends

a

“Low”

pulse

to

the A

input

of

U3,

a

74L$123.

The

RC

network

connected

to

the

RxCx

and

Cx

pins

create

a

time

constant,

t

=

0.45xRxC

=

0.263

seconds.

If

a

pulse

is

not

received

at

the

input

before

the

time

constant

expires,

the

output

will

go

“Low".

The

high

priority

alarm

will

then

be

activated

due

to

the

microcontroller

failure.

Note

when

the

microcontroller

detects

a

high

priority

alarm

condition,

pulses

to

the

watch

dog

circuit

stop.

Alarm

Tone

Generator

and

Control

Circuits

The

alarm

circuit

consists

of

an

alarm

tone

generator

and

control

circuitry

for

high

or

low

prior-

ity

alarm

conditions.

Under

a

no

alarm

condition

the

7556

timers

are

both

inactive,

(reset

lines

low).

Low

Priority

Alarm

Under

normal

operating

conditions

the

input

to

U8

9 is

“High”.

When

the

microcontroller

detects

a

low

priority

alarm

a

1

Hz

square

wave

is

output

to

U8

9.

The

timer

activates,

causing

a

2

kHz

audio

output.

This

results

in

a

one

second

“On”,

one

sec-

ond

“Off"

audio

alarm.

The

2

kHz

signal

is

adjusted

within

+

100

Hz

by

R38.

The

volume

of

the

audio

alarm

is

adjusted

by

R37. This

should

be

adjusted

fully

CCW

for

maximum

volume.

High

Priority

Alarm

The

high

priority

alarm

is

activated

if

the

microcon-

troller

quits

sending

pulses

to

the

watchdog

timer.

This

occurs

when

a

high

priority

alarm

condition

is

detected

or

if

the

microcontroller

fails.

The

high

priority

alarm

is

also

activated

if

the

hardware

triac

test

circuitry

detects

a

failed

triac.

Both

timers

be-

come

active

with

one

timer

feeding

a

1

Hz

signal

to

the

control

line

of

the

second.

The

1

Meg

resistor

changes

the

output

frequency

of

the

second

timer

to

produce

a

warbling

effect

(two

tone

alternating

alarm).

If

high

and

low

priority

alarms

are

both

“On",

the

output

of

the

“And”

gate

overrides

the

low

priority

signal,

keeping

both

timers

active.

1/Functional

Description

Heat

Control

Routine

Proportional

control

of

the

heater

power

is

obtained

by

varying

the

number

of

full

heat

cycles

of

ac

cur-

rent

delivered

to

the

heater.

To

allow

for

line

vol-

tage

compensation

and

stili

have

at

least

20

dis-

creet

levels

of

heat,

a

proportioning

range

of

0

to

60

full

heat

cycles

was

selected.

In

other

words,

at

very

low

line

voltages,

100%

heat

will

be

output

by

having

the

heat

“On”

for

60

full

cycles

out

of

a

pos-

sible

maximum

of

60.

Similarly,

at

this

low

line

vol-

tage

90%

heat

is

obtained

by

having

the

heat

"On"

for

54

out

of

60

cycles.

In

the

“manual”

mode

of

operation,

the

heat

output

is

determined

by

the

bargraph

setting

selected

by

the

operator.

There

are

20

steps

on

the

bargraph

so

each

step

represents

a

5%

heat

increment.

To

accomplish

the

desired

compensation

for

line

vol-

tage

variations,

the

maximum

number

of

heat

cycles

is

calculated

based

on

the

last

measurement

of

the

power

line

voltage.

For

115v

nominal

units,

at

106

volts

or

less,

the

maximum

number

of

heat

cycles

is

60.

At

greater

than

125

volts

the

maximum

number

of

heat

cycles

is

40

cycles

out

of

a

possible

60.

Therefore,

the

number

of

cycles

of

current

furnished

to

the

heater

in

the

manual

mode

is

determined

by

multiplying

the

maximum

for

the

line

voltage

pre-

sent

by.the

bargraph

setting.

For

example:

assume

the

line

voltage

is

115v

(maximum

number

of

cycles

“On"

=

50)

and

the

bargraph

setting

is

30%;

the

number

of

heat

cycles

to

be

output

will

be

0.3

times

50

=

15

cycles.

Under

these

conditions

the

heat

will

be

“On”

for

15

cycles

and

“Off”

for

45

cycles,

this

sequence

will

continue

until

the

line

voltage

changes

or

the

setting

is

changed

on

the

bargraph.

In

the

“servo”

mode,

the

heater

power

is

controlled

by

comparing

the

patient's

skin

temperature

to

the

selected

value

of

control

temperature.

The

differ-

ence

between

the

control

temperature

and

the pa-

tient

temperature

is

referred

to

as"PTG"

(patient

temperature

gradient).

A

positive

PTG

indicates

a

patient

is

cooler

than

the

control

temperature

and

a

negative

PTG

occurs

when

the

patient

temperature

is

higher

than

the

control

temperature.

Based

on

the

magnitude

and

sign

of

the

PTG,

a

software

look-

up

table

is

used

to

find

the

percent

heat

required.

The percent

heat

is

then

converted

to

the

appropri-

ate

number

of

bargraph

steps

and

then

the

selected

amount

of

heat

is

output

by

the

same

process

used

in

the

manual

mode.

A

hardware

circuit

is

used

to

interrupt

the

micro-

controller

once

every

cycle

of

the

ac

power

line.

During

the

interrupt

routine,

two

registers

are

de-

cremented

to

keep

track

of

the

heater

"On"

and

“Off”

cycles.

One

register

is

used

for

counting

the

total

interval

(60)

and

another

register

is

loaded

on

every

sixtieth

count

with

the

number

of

heat

cycles

to

be

output.

A

flag

is

set

whenever

this

register

is

not

zero,

the

heat

is

“On”

only

when

this

flag

is

set.

The

operation

of

the

heat

control

software

and

the

heat

output

hardware

are

repeatedly

tested

during

operation

of

the

warmer.

An

opto-isolator

connected

with

a

series

resistor

directly

actoss

the

heater

ter-

minals

is

used

to

monitor

heater

power.

The

output

of

the

opto-isolator

is

fed

into

a

Schmitt

trigger,

which

outputs

directly

to

an

input

port

of

the

micro-

controller.

Therefore,

the

microcontroller

can

verify

if

the

heat

is

actually

on

when

it

is

supposed

to

be

on.

If

not,

a

system

fail

alarm

will

be

activated.

Approxi-

mately

every

three

minutes,

an

external

hardware

network

(safety

circuit)

signals

the

microcontroller

to

switch

“Off"

the

heat.

This

hardware

also

moni-

tors

the

output

of

the

Schmitt

trigger

(heater

status

line).

If

the

heater

power

is

not

switched

“Off”

after

a

short

delay,

the

hardware

circuit

will

de-energize

the

“safety”

relay

to

switch

“Off”

heater

power

and

algo

initiate

an

alarm

which

cannot

be

silenced

without

switching

the

power

“Off".

Service

Features

The

electronic

controller

assembly

is

easily

removed

for

servicing

or

calibration.

This

controller

contains

all

the

circuitry

and

components

except

for

the

hea-

ter,

alarm

lamps,

and

observation

lamps.

All

indicators

and

the

audio

alarm

are

activated

on

power-up

for

operator

verification

of

proper

display

operation.

These

can

also

be

activated

by

depres-

sing

the

alarm

silence

switch

for

2

seconds.

In

addi-

tion

the

software

revision

number

and

the

line

fre-

quency

are

displayed.

Test

points

on

the

printed

circuit

boards

are

acces-

sible

for

troubleshooting

and

calibration

without

re-

moval

of

the

boards.

In

addition

integrated

circuits

with

24

pins

or

more

have

sockets

to

aid

in

troub-

leshooting

and

repair.

Software

routines

are

built

into

the

warmer

to

pro-

vide

test

functions,

to

aid

in

troubleshooting,

calib-

ration,

and

operation

verification.

These

test

routines

are

activated

using

à

DIP

switch

located

on

the

control

board.

Some

of

the

test

routines

can

be

activated

using

the

display

panel.

Calibration

may

be

verified

on

the

controller

display

without

disassembly.

A

high

calibration

point

and

a

low

calibration

point

are

displayed

when

the

service

test

switch

is

pressed

for

2

seconds.

Line

voltage

is

monitored

by

the

warmer

and

fluctu-

ations

of

+

10%

from

nominal

voltage

are

compen-

sated

for

so

that

heat

output

is

held

constant.

If

the

voltage

exceeds

+

17.5%

from

nominal

an

alarm

is

activated

and

the

heater

switches

off.

Self

Test

Functions

The

following

text

is

a

description

of

the

self

test

functions

performed

by

the

infant

warmer.

If

an

error

results

on

any

of

the

power-up

or

on-line

tests

then

the

error

number

will

be

displayed

on

the

elapsed

time

display

in

the

format

E

##.

The

high

priority

alarm

(System

Failure

LED)

will

be

“On"

and

cannot

be

silenced.

Power

must

be

switched

“Off”

to

reset

this

alarm.

1-5

1/Functional

Description

Power

Up

Testing

On

power

up

the

following

tests

are

performed.

1.

Instruction

Test

(Error

#01)

Selected

instructions

are

tested

and

verified

opera-

tional.

2.

Checksum

(Error

#04)

The

hex

values

of

Eprom

locations

from

0000

to

1FFD

are

added

together

and

a

2

byte

sum

is

stored.

Eprom

locations

1FFE

and

1FFF

contain

a

2

byte

number

which

when

added

to

the

calculated

checksum

should

total zero.

3.

RAM

Test

(Error

#05)

Rams

10

through

7F are

tested

with

patterns

of

00,

FF,

AA,

and

55.

4.

Test

Port

1

Lines

(Error

#06)

The

port

one

I/O lines are

tested

to

verify

they

can

be

toggled.

On

Line

Testing

The

following

tests

are

run

during

the

normal

oper-

ation

of

the

software.

An

error

on

any

of

these

tests

results

in

a

System

Failure alarm.

1.

ADC

Calibration

Test

(Cal

High

Error

#02,

Cal

Low

Error

#03)

Verifies

that

readings

of

the

precision

calibration

re-

sistors

are

within

0.3

degrees

of

the

nominal

values.

These

readings

can

be

checked

by

depressing

the

hidden

switch

on

the

display

panel

(located

directly

above

the

alarm

silence

switch)

for

2

seconds.

After

2

seconds

the

displays

should

indicate

as

fol-

lows:

‘Patient

Temperature

is

25.0

+

0.3

degrees.

Control

Temperature

is

37.9

+ 0.3

degrees.

2.

Hardware

Triac

Test

A

circuit

independent

of

the

microcontroller

moni-

tors

that

the

micro

can

switch

the

heat

“Off”.

Every

3

minutes

24

seconds

in

60

Hz

operation

(4

minutes

and

5

seconds

for

50

Hz

operation)

a

request

is

made

to

the

micro

to

switch

the

heat

“Off”.

If

the

heat

does

not

go

“Off",

a

hardware

latch

is

latched

and

a

relay

contact

is

opened

so

thera

is

no heat.

This

verifies

that

the

triac

is

not

shorted

and

that

the

micro

is

still

able

to

control

the

heat.

This

failure

does

not

display

an

error

number

because

it

is

not

controlled

by

the

micro

but

will

cause

the

software

triac

test

to

fail

when

heat

is

called

for

by

the

pro-

gram.

3.

ADC

Converter

not

Converting

(Error

#07)

Verifies

that

the

ADC

conversion

complete

occurs

within

1.second.

4.

Hardware

Triac

Timer

Not

Running

(Error

#08)

Verifies

that

the

request

from

the

hardware

triac

test

circuit

occurs

within

256

seconds.

5.

Software

Triac

Test

(Error

#09)

The

heater

status

line

is

checked

to

verify

that

the

heat

is

“On”

when

the

micro

is

switching

it

“On”.

This

verifies

that

the

triac

is

not

failed

open.

1-6

6.

Line

Voltage

Out

of

Range

(Error

#10)

Verifies

that

the

line

voltage

is

within

the

range

of

82.6%

to

117.4%

of

nominal

input

voltage.

(95v

to

135v,

for

115v

units)

Diagnostic

Testing

Diagnostic

testing

can

be

accessed

by

one

of

the

following:

1.

Depressing

and

holding

the

Apgar

Tones

switch

while

powering

up

unit.

This

causes

the

unit

to

cycle

in

the

self

test

loop

until

power

is

removed.

See

Self

Test

Loop

in

step

2e.

2.

Selecting

one

of

the

test

positions

on

the

4

posi-

tion

“Dip”

switch

located

on

the

control

board.

Following

is

a

description

of

the

functions

of

the

“Dip”

positions:

a.

Switches

All

Open

(“Off”)

Normal

Operating

Posi-

tion

(00).

b.

Switches

2,3,4,

Closed

(“On”)

and

Switch

1

Open

(“Off”)

Hardware

Triac

Test

(0E)

.

This

mode

can

be

used

to

test

the

hardware

triac

test

circuit.

The

heat

is

switched

“On”

all

the

time

to

simulate

a

failed

triac.

The

elapsed

time

display

will

start

at

zero

on

power

up

and

display

the

elapsed

time.

At

about

3

minutes

24

seconds

for

60Hz

operation

(4

minutes

and

5

seconds

for

50

Hz

operation)

a

failed

triac

should

be

detected.

The

high

priority

audio

alarm

should

come

“On”

and

the

heat

should

go

“Off".

The

heat

indicator

LED

lo-

cated

on

the

control

board

should

be

checked

to

verify

that.

the

heat

is

“Off”.

c.

Switches

1,2,3,

Open

(“Off”)

and

Switch

4

Closed

(“On")

ADC

Calibration

(08)

The

system

displays

the

actual

ADC

counts

on

the

elapsed

time

display,

the

patient

temperature

on

the

patient display

even

if

outside

of

the

normal

dis-

played

range,

and

the

%

of

nominal

line

voltage

on

the

control

display.

This

position

is

used

for

calibrat-

ing the

analog

to

digital

converter

and

the

line

vol-

tage

compensation

circuit.

d.

Switches

1,2,4

Open

(“Off”)

and

Switch

3

Closed

(“On”)

Alarm

Calibration

(04)

All

segments

of

all

LEDS

are

lit.

The

heater,

over-

head

alarm

lamps,

and

the

observation

lamp

are

on.

The

audio

alarm

emits

a

steady

low

priority

alarm

sound.

The

2

kHz

alarm

frequency

can

be

adjusted

using

this

mode.

e.

Switches

All

Closed

(“On”)

Self

Test

Loop

(0F)

In

this

mode

the

unit

cycles

through

a

display

test,

checks

ADC

calibration,

cycles

the

heater,

alarm

lights,

and

observation

lights,

and

steps

through

the

tests

described

in

power

up

testing.

It

also

monitors

the

touch

switches

and

sounds

the

critical

alarm

while any

switch

is

depressed.

If

any

error

occurs

the

error

number

will

be

displayed

on

the

elapsed

time

display

and

the

critical

alarm

will

sound

for

two

seconds, The

program

will

then

continue

to

loop

through

this

test,

even

if

the

4

DIP

switches

are

retumed

to

“Open”

(“Off”).

1/Functional

Description

If

the

test

loop

is

entered

on

power

up

by

depres-

sing

the

Apgar

Tones

switch

the

program

will

loop

until

an

error

is

detected.

If

an

error

is

detected

the

unit

will

then

stop

the

test

loop,

the error

code

will

be

displayed

in

the

elapsed

time

display,

and

the

critical

alarm

will

sound.

The

power

must

be

switched

“Off"

to

exit this

mode.

Self

Test

Loop

The

unit

cycles

in

the

following

loop

until

the

power

is

removed.

Power

up

tests

performed:

Instruction

test

(“Error"

#01)

Check

calibrate

high

(“Error"

+02)

Check

calibrate

low

(“Error"

#03)

Checksum

(“Error"

#04)

Ram

test

("Error"

#05)

Test

port

1

lines

(“Error”

#06)

Check

if

ADC

is

converting.

(“Error”

+07)

Display

loop

test:

Seven

Seg

Bar

Graph Alarm

LEDs

Display's

Segments

All

1's

1,11

Probe

fail

All

2's

2,12

Pat

temp

All

3's

3,13

Sys

fail

All

4's

4,14

Heater

“Off”

Ail

S's

5,15

Reset

timer

Al

6's

6,16

Spare

LED

All

7's

7,17

All

“Off”

All

8's

8,18

All

“Off”

Al

Ys

9,19

Al

"Off"

All

0's

10,20

All

“Off”

Al

"Off"

All

“Off"

Al

"Off"

The

unit

returns

to

start

of

self

test

loop.

Error

Codes

Error

Description

#01

Instruction.test

fails

#02

Calibrate

high

fails

#03

Calibrate

low

fails

#04

Checksum

fails

#05

Ram

test

fails

#06

Port

1

lines

#07

ADC

not

converting

#08

Hardware

triac

timer

#09

Heat

not

controlled

#10

Line

voltage

out

of

range.

Mode

LEDs

Heater

and

Lights

Servo

“On"

Servo

“Off”

Servo

“On"

Manual

“Off”

Manual

“On"

Manual

“off”

Apgar

“On”

Apgar

“Off”

Apgar

“On”

All

“Off”

"Off"

All

“Off”

Possible

Cause

Microprocessor

8031

defective

ADC

calibration

Cal

high

resistor

defective

ADC

calibration

Cal

low

resistor

defective

Eprom

defective

Microprocessor

8031

defective

Microprocessor

8031

defective

VO expander

8243

defective

Microprocessor

8031

defective

A/D

Converter

ADC3711

defective

Voltage

Reference

LM10

defective

I/O

expander

8243

#2

defective

Logic

gate

4020B

defective

IC

in

triac

test

area

defective

Heater

triac

defective

Microprocessor

8031 defective

Heater

opto-isolator

or

driver

defective

Line

voltage

compensation

pot.

on

power

supply

board

not

calibrated.

1-7

1/Functional

Description

C.

Display

Board

This

is

a

functional

description

for

the

Infarit

Warmer

System

Display

Board

Part

No.

0631-5031-

700.

Refer

to

Schematic

No.

0676-0325-000

for

a

de-

tailed

circuit

diagram.

The

display

board

provides

the

interface

between

the

operator

and

the

control

system.

It

displays

the

status

of

the

unit,

the

patient

status,

and

can

also

be

used

as

a

diagnostic

aid.

The operator

controls

the

system

by

depressing

the

various

switches

on

the

front

display.

Operation

of

the

display

board

is

simplified

with

the

use

of

two

ICs:

the

8243

I/O

ex-

pander

which

is

used

in

conjunction

with

the

switches;

and

the

MM5451

(or

MM5450)

driver

used

in

conjunction

with

the

LED

display.

Switch

Decoding

The

I/O

expander,

U1,

is

always

enabled

in

the

read

mode

because

its’

sole

purpose

is

to

detect

switch

depressions.

The

8243

is

activated

by

the

microcon-

troller

sending

a

“Low”

signal

on

the

Chip

Select

(CS)

line.

A control

word

(4

bits)

is

latched

from

the

input

port

2

on

the

“High”

to

“Low”

transition

of

the

PROG

pin.

The

word

is

decoded

as

follows.

Instruction

Address

P23

P22

Code

P21

P20

Code

0 0

Read

0 0

Port

4

0

1

Write

0

1

Port

5

1

0

Or

1

0

Port

6

1

and

1

Port

7

As

soon

as

the

read

instruction

and

the

port

ad-

dress

are

decoded

the

corresponding

port

lines

are

set

to

a

“High”

impedance

state

and

the

input

buf-

fers

within

the

8243

are

switched

“On”.

When

a

switch

is

depressed

on

the

display,

the

respective

line

switches

“Low”

and

is

loaded

into

the

input

buffer.

The

“Low”

to

“High”

transition

on

the

PROG

line

terminates

the

read

instruction

and

transfers

in-

formation

back

to

port

2.

When

the

microprocessor

sets

the

CS

line

“High”

the

8243

is

disabled.

1-8

LED

Display

Driver

The

LED

display,

driver,

U2,

controls

the

LED

dis-

plays.

The

displays

are

multiplexed

with

a

duty

cycle

of

20%

and

a

refresh

rate

of

60

hertz.

Data

is

input

to

22

synchronously

with

the

clock

(pin

21).

The

first

“1"

bit

activates

the

driver

and

35

data

bits

will

follow.

After

the

35th

bit

is

loaded

the

data

is

latched

to

provide

direct

output.

Note

that

a

logic

“High”

at

the

input

switches

the

output

“Low"

and

switches

“On”

the

LED

connected

to

the

output

(output

is

inverted).

Brightness

Adjust

R9

is

used

to

adjust

the

output

current

from

U2

and

in

tum

change

the

brightness

of

the

LEDs.

R9

is

ad-

justed

to

produce

3.30

+

0.10

volts

across

R10

(3.3V/221

ohms

=

15ma).

C6

is

used

to

prevent

os-

cillations

at

19.

Multiplexing

of

Displays

Since

there

are

not

enough

data

bits

to

drive the

en-

tire

display,

the

displays

are

divided

into

four

sec-

tions.

Bits

1-28

are

used

to

supply

the

necessary

in-

formation

to

each

section.

Bit

29

is

unused.

Bit

30

is

tied

to

a

221

ohm

+

1%

resistor

which

is

used

for

calibration.

Bits

31-34

select

which

channel

of

the

display

is

activated

by

switching

ON

a

Darlington

transistor.

The

Darlington

provides

a

large

gain

so

that

a

small

drive

current

will

sustain

the

large

cur-

rent

draw

from

the

LEDs.

A

string

of

35

zeroes

are

sent

on

the

data

line

every

fifth

update

cycle.

The

driver

has

a

serial

input

and

does

not

have

a

master

reset.

This

string

of

zeroes

resets

the

driver

in

case

an

extra

pulse

was

entered

by

a

noise

spike.

The

basic

circuit

for

one

LED

segment

consists

of

the

5

volt

LED

supply

(reduced

to

4.3

volts

by

a

series

1N4001

diode,)

a

Darlington

switch

to

enable

the

supply

to

the

LED

group,

and

the

MM5451

driver

to

select

a

low

voltage

return

for

the

segment

(if

selected).

2/Specifications

All

specifications

are

subject

to

change

without

notice.

2.1

Electrical

Power

Requirements

Model

3000

0305-0402-910

120

V

50/60

Hz

Models

115V~

+

10%

5.7

Amps

0305-0402-911

220

V

50/60 Hz

Models

220V~

+

10%

3.0

Amps

0305-0402-912

240

V

50/60 Hz

Models

240V~

+

10%

2.7

Amps

0305-0402-913

100

V

50/60

Hz

Models

95V“

+

10%

6.4

Amps

Model

3300

0305-0403-910

120

V

50/60

Hz

Models

115V

~

+

10%

5.7

Amps

0305-0403-911

220

V

50/60 Hz

Models

220V~

+

10%

3.0

Amps

0305-0403-912

240

V

50/60 Hz

Models

240V

”

+

10%

2.7

Amps

0305-0403-913

100

V

50/60

Hz

Models

95V~

+

10%

6.4

Amps

These

models

were

designed

to

conform

to

IEC

601-

1

requirements,

Nominal

Power

Consumption

500

watts

at

maximum

%

power

setting.

Heater

Output

440

watts

+

5%

at

maximum

%power

setting.

Average

Energy

at

Mattress

Level

is

35

mw/cm2

at

Maximum

%

power

setting

Recommended

Bed

Level

(Model

3000)

27

inches

+

2inches

from

the

bottom

of

heater

mod-

ule.

CAUTION:

For

the

Model

3000

Infant

Warmer

Sys-

tem

the

height

of

the

bed

should

be

27

inches

+

2

inches

from

the

bottom

of

the

heater

module

for

proper

heating

and

temperature

control.

Line

Voltage

Compensation

Input

voltage

is

monitored

and

the

heat

output

is

adjusted

to

compensate

for

variations

of

line vol-

tage.

Circuit

Breaker

Rated

Current:

7

Amps

Trip

Point:

9.45

Amps

Minimum

Type:

Manual

Resetting

Model:

Airpax

Snapak

Chassis

Leakage

Current

Less

than

8

microamperes

on

100v

and

120v

units

(18

microamperes

on

220v and

240v

units)

measured

at

the

patient

probe

connection.

Less

than

90

microamperes

on

100v

and

120v

units

{180

microamperes

on

220v

and

240v

units)

mea-

sured

at

an

exposed

metal

surface.

2.2

Controller

Electronics

Microprocessor

based

control

system.

Self

test

func-

tions

are

performed

at

power

up

and

during

normal

operation.

Power

Control

Method

Proportional

heat

control

with

zero

voltage switch-

ing

to

minimize

radiated

and

conducted

EMI.

Examination

Light

Nominai

illuminance

output:

100

foot

candles

at

center

of

mattress.

Estimated

lamp

life:

3,000

hours

Temperature

Sensing

System

Probe

Model

Number:

LA003

Range:

22-42

degrees

C

Accuracy:

+

0.3

degrees

C

Resolution:

+ 0.1

degrees

C

Probe

interchangeability:

+

0.1

degrees

C

Elapsed

Timer

60

minute

elapsed

timer

with

hold

mode

and

Apgar

tones.

Manual

Mode

Manual

mode

heat

selector

range:

0

to

440

watts

in

20

increments

(5%

per

step).

Servo

Mode

Servo

control

range

36.0

to

37.5

degrees

C

in

incre-

ments

of

0.1

degrees

C.

2.3

Alarms

Multiple

audio

tones

1.

Operator

prompt

tone

2.

Alternating

single

tone

3.

Alternating

two

tone

Overhead

Alarm

Light

一

Large

alarm

light

located

on

the

front

of

the

heater

assembly

for

easy

visual

identification.

Probe

Failure

Alarm

Activates

when

the

skin

temperature

probe

fails

electrically

open

or

short,

or

is

disconnected

from

the

warmer.

The

alarm

is

only

active

in

the

servo

mode.

The

heater

is

tumed

off

and

the

patient

tem-

perature

display

flashes

HH.H

when

this

alarm

con-

dition

exists.

2/Specifications

Patient

Temp.

Alarm

The

Patient

Temp.

alarm

activates

in

the

servo

mode

when

the

difference

between

the

patient

tem-

perature

and

the

control

temperature

is

greater

than

one

degree

C.

The

alarm

cancels

when

the

patient

temperature

returns

to

within

0.8

degrees

C

of

the

control

temperature.

System

Failure

Alarm

The

system

failure

alarm

activates

and

turns

the

heater

off

if

the

analog

to

digital

converter

calibra-

tion

drifts

by

more

than

0.3

degrees

C.,

the

heater

triac

fails,

the

microprocessor

fails,

or

the.self

check

functions

fail

on

power-up.

This

alternating

two

tone

alarm

cannot

be

silenced.

Heat

Off

Alarm

The

LED

activates

whenever

the

heater

is

in

the

X-

ray

position.

The

audio

alarm

activates

after

5

min-

utes

in

the

X-ray

position.

Check

Patient

Alarm

Activates

in

the

manual

mode

if

the

heater

has

been

energized

at

greater

than

25%

heat

for

12

con-

tinuous

minutes.

In

the

servo

mode

the

alarm

acti-

vates

when

the

heater

has

been

at

full

power

for 12

continuous

minutes.

Power

Failure

Alarm

The

power

failure

alarm

activates

if

line

power

is

in-

terrupted.

A

rechargeable

maintenance

free

ni-cad

battery

powers

the

audio

alarm

and

the

micropro-

cessor.

If

power

is

restored

within

10

minutes

the

mode

of

operation

and

the

set

point

are

recalled.

2.4

Environmental

Operating

temperature

range:

10

to

40

degrees

C

Storage

temperature

range:

-25

to

60

degrees

C

Humidity:

0

to

95%

2.5

Mechanical

(without

accessories)

Dimensions:

Height:

73in.

(185cm.)

Depth:

39.5in.

(100cm.)

Width:

24.5in.

(62cm.)

Mattress:

18.2

x

25.2

inches

(46.2

x

64.0

cm)

2-2

Tilting

Positions

+

10

degrees

Weight:

Model

3300

—

approx.

210

pounds

(95

kg.)

Model

3000

—

approx.

165

pounds

(75

kg.)

Casters:

5

inch

diameter,

2

locking,

2

non-locking

2.6

Accessories

Oxygen

yoke

and

regulator:

indexed

yokes

accommodate

two

E

size

oxygen

cylinders

Diss

oxygen

fittings

52 +

2

psig

regulator

Cylinder

pressure

gauge,

0

to

3000

lbs.

(0

to

210

kg/

cm2)

Three

drawer

storage

accessory:

Drawers

15

X

15.5

X4

inches

(930

cubic

inches

per

drawer)

38

x

39

x

10

cm.

(14,820

cubic

centimeters

per

drawer)

Rail

mounted

accessories:

Monitor

shelf:

Dimensions

12

x

26

inches

(30

x

66

centimeters)

Load

limit:

50

pounds

(22

kg)

Instrument

shelf:

Dimensions

12

x

12

inches

(30

x

30

centimeters)

Load

limit:

20

pounds

(9

kg}

WARNING:

Overloading

the

shelves

can

affect

the

stability

of

the

unit.

Oxygen

flowmeter

w/DISS

fittings

(0

to

15

LPM)

Air

flowmeter

w/DISS

fittings

(0

to

15

LPM)

Manometer

(-20

to

+

100

centimeters

of

water)

TV

pole

Vacuum

manifold

w/DISS

fittings

Gas

manifold

w/

1/8”

npt

fitting

3.5

inch

utility

post

22

inch

utility

post

for

mounting

infusion

pumps,

humidifiers,

proportioners,

ventilators

etc.

Ventilator

mounting

accessory

3/Setup

and

Checkout

Procedure

3.1

Setup

Refer

to

the

setup

instructions

shipped

with

the

In-

fant

Warmer

System

for

initial

unpacking

and

setup

of

the

unit

after

shipment.

Inspect

the

Model

3000

and

3300

Warmer

Systems

and

all

accessory

items

after

removal

from

the ship-

ping

containers

for

any

signs

of

damage

that

may

have

occurred

during

shipment.

File

a

damage

claim

with

the

shipping

carrier

if

damage

has

occurred.

Also

confirm

the

presence

of

all

accessory

items

as

listed

on

the

packing

slip.

3.2

Checkout

Procedure

WARNING:

Do

not

perform

the

Check-Out

Proce-

dure

while

a

patient

occupies

the

Infant

Warmer

System.

Perform

the

Checkout

Procedure

before

each

use

on

a

patient.

Refer

servicing

to

qualified

service

person-

nel

if

the

unit

does

not

perform

as

specified.

Refer

to

the

Troubleshooting

Guide

and

the

Disassembly

and

Repair

Sections

if

the

unit

fails

any

steps

of

the

Checkout

Procedure.

A.

Mechanical

Checks

(Model

3000

and

3300)

Overall

Appearance

1.

Disconnect

the

power

cord

for

the

Infant

Warmer

System

for

the

mechanical

checks

portion

of

this

procedure.

2.

Check

the

overall

appearance

of

the

Infant

Warmer

System.

There

should

be

no

obvious

damage.

3.

Place

the

Infant

Warmer

System

on

a

level

sur-

face.

Check

that

all

four

casters

are

in

firm

con-

tact

with

the

floor

and

that

the

warmer

moves

freely.

4.

Lock

the

two

front

casters

and

check

that

the

warmer

is

held

in

place.

5.

Examine

the

power

cord

for

damage.

Replace

the

power

cord

if

damage

is

evident.

CAUTION:

Insulation

on

electrical

wiring

can

de-

teriorate

with

age.

Check

for

brittle

or

deteriorated

insulation

on

power

cord

and

all

other

electrical

wiring.

Heater

Rotation

1.

Rotate

the

heater

to

the

X-ray

position

and

back

to

the

normal

position,

Check

for

smooth

rotation.

Mechanical

Checks

(Model

3300)

1.

Check

the

operation

of

the

bed

sides.

The

bed

sides

should operate

smoothly.

2.

Check

the

operation

of

the

tilt

mechanism.

Verify

that

the

bed

platform

operates

smoothly

and

jocks

in

any

position.

Optional

Accessory

Checks

Check

that

all

accessories

are

mounted

securely

to

the

uprights.

Oxygen

Yoke

and

Regulator

Checks

.

Check

that

all

oxygen

cylinders

are

mounted

sec-

urely.

2.

Check

that

the

output

from

the

regulator

is

52

+

2

psig

with

a

500

cc

flow.

If

adjustment

is

re-

quired

refer

to

section

4H.

B.

Control

Unit

Checks

1.

Connect

the

Infant

Warmer

power

cord

to

an

ap-

propriate

power

source

(see

rating

plate

for

prop-

er

voltage

etc.).

Switch

the

power

“On”

and

ver-

ify

the

following:

a.

The

alternating

two

tone

audible

alarm

sounds

and

all

displays

and

indicators

are

lit

for

approxi-

mately

two

seconds.

Note:

During

this

time

the

controller

also

per-

forms

self

check

functions.

If

the

controller

de-

tects

a

failure

the

alarm

stays

on

and

service

is

required.

b.

The

manual

mode

indicator

is

lit.

с.

An

operator

prompt

tone

sounds

and

the

%

power

display

flashes.

2.

Adjust

the

heat

output

with

the

increase

and

de-

crease

touch

switches

to

the

high

and

low

limits

as

indicated

by

the

%

power

display.

3.

Connect

the

skin

temperature

probe

to

the

Infant

Warmer

System.

4.

Press

the

mode

touch

switch

to

place

the

warmer

in

the

servo

mode

and

verify

the

follow-

ing:

Note:

An

alternating

two

tone

alarm

and

a

flash-

ing

overhead

alarm

light

may

occur

here

if

the

skin

temperature

probe

is

below

30

degrees

C.

Warm

the

probe

with

your

fingers

or

silence

the

alarm.

.

The

servo

mode

indicator

is

lit.

.

An

operator

prompt

tone

sounds

and

the

control

temperature

display

flashes

36.5

degrees

C.

vp

5.

Press

the

increase

touch

switch

and

verify

that

the

maximum

servo

control

temperature

attaina-

ble

is

37.5

degrees

C.

Note:

A

patient

temperature

alarm

occurs

if

the

difference

between

the

patient

temperature

and

the

control

temperature

is

greater

than

one

de-

gree

C.

6.

Press

the

decrease

touch switch

and

verify

that

the

minimum

servo

control

temperature

attaina-

ble

is

35.0

degrees

C.

M

.

Disconnect

the

skin

temperature

probe.

Verify

the

following:

.

The

probe

failure

indicator

light

is

lit.

.

There

is

an

alternating

two

tone

alarm.

The

overhead

alarm

light

is

flashing.

.

The

patient

temperature

display

flashes“HH.H”.

m

ASFP

.

Press

the

alarm

silence

touch

switch

and

verify

the

following:

.

The

probe

failure

indicator

light

is

lit.

.

The

alternating

two

tone

alarm

is

silenced.

.

The

overhead

alarm

light

is

lit.

.

The

patient

temperature

display

indicates

"HH.H".

e.

After

one

minute

the

alternating

two

tone

alarm

sounds,

the

overhead

alarm

flashes

and

the

pa-

tient

temperature

display

flashes

HH.H.

ao

op

9.

Switch

to

the

manual

mode

and

set

the

heat

at

25%

power.

3/Setup

and

Checkout

Procedure

Elapsed

Timer

Check

1.

Press

the

start/hold

switch

to

activate

the

elapsed

timer.

Verify

that

the

timer

starts

opera-

tion.

2.

Press

the

on/off

switch

for

the

Apgar

tones.

Ver-

ify

that

the

indicator

light

for

the

Apgar

tones

is

not

lit.

3.

Press

the

on/off

switch

for

the

Apgar

tones

again.

Verify

that

the

indicator

light

for

the

Apgar

tones

is

lit.

4.

Press

the

start/hold

touch

switch.

Verify

that

the

present

elapsed

time

is

held.

5.

Press

the

start/hold

touch

switch

and

verify

that

the

timer

updates

to

the

current

elapsed

time

and

the

Apgar

tones

continue

to

sound

at

the

specified

times

(at

1

minute

and

at

every

5

min-

ute

interval

after

the

elapsed

timer

is

started).

6.

Press

the

reset

touch

switch

and

verify

that

the

timer

indicates

00:00.

If

the

elapsed

timer

is

not

used

for

one

minute

the

display

is

switched

off.

Examination

Light

Check

1.

Press

the

Light

“On"/“Off"

touch

switch.

Verify

that

the

examination

light

functions.

Interlock

Switch

Check

1.

Place

the

warmer

in

the

manual

mode

at

25%

power

output.

2.

Rotate

the

heater

assembly

to

the

X-ray

position.

Verify

that

the

heater

off

indicator

light

is

“On”

and

the

%

power

display

indicates

0%

heat.

3.

Rotate

the

heater

assembly

to

the

normal

operat-

ing

position.

Verify

that

the

heater

off

indicator

light

is

“Off”

and

the

%

power

display

indicates

25%.

Display

and

Alarm

Check

1.

Press

and

hold

the

alarm

silence

switch

for

more

than

2

seconds,

then

check

for

the

following:

a.

Every

segment

of

each

digital

display

should

be

lit.

All

segments

should

be

of

uniform

brightness

and

visible

under

ordinary

room

lighting

condi-

tions.

b.

All

LED

indicators

should

be

lit.

c.

The

warbling

two-tone

audio

alarm

should

be

on.

Battery

Test

and

Memory

Test

The

battery

is

charged

in

normal

operation

by

a

trickle

charge

current

from

the

regulated

9

volt

sup-

ply.

If

the

battery

is

discharged

it

must

be

re-

charged

before

allowing

a

patient

to

occupy

the

In-

fant

Warmer.

The

battery

may

be

recharged

by

placing

the

unit

in

the

manual

mode

at

a

0%

heat

setting.

If

the

battery

is

defective,

replace

it.

Re-

placement

of

the

battery

is

recommended

every

two

years.

There

is

no

maintenance

required

for

the

bat-

:

tery.

3-2

Note:

The

battery

must

be

fully

charged

to

pass

the

10

minute

test

or

partially

charged

to

pass

the

two

minute

test.

1.

Disconnect

the

patient

temperature

probe.

2.

Place

the

Infant

Warmer

in

“servo”

mode.

3.

Silence

the

probe

failure

alarm.

4.

Set

the

control

temperature

at

37.0

degrees

C.

5

.

Remove

the

Infant

Warmer

power

plug

from

the

power

source

for

two

minutes.

Do

not

switch

the

power

"Off".

The

power

failure

alarm

should

sound

for

two

minutes.

Note:

If

the

power

failure

alarm

is

tested

for

10

minutes,

the

Infant

Warmer

must

be

connected

to

the

correct

power

source

and

operated

for

24

hours

to

recharge

the

battery

before

allowing

a

patient

to

occupy

the

Infant

Warmer.

6.

Reconnect

the

Infant

Warmer

to

the

power

source.

Verify

the

following:

a.

The

Infant

Warmer

is

operating

in

the

servo

mode.

b.

The

control

temperature

is

37.0

degrees

C.

c.

The

audio

power

failure

alarm

is

off.

Calibration

Check

1.

Press

and

hold

the

hidden

control

panel

switch

(directly

above

the

alarm

silence

switch).

2.

After

2

seconds

the

displays

should

indicate

as

follows:

a.

Patient

Temperature

displays

25.0

+

0.1

degree.

b.

Control

Temperature

displays

37.9

+ 0.1

degree.

c.

Elapsed

Time

displays

%

nominal

line

voltage

+

2%.

Note:

Line

voltage

may

be

measured

on

terminals

marked

with

the

phase

symbol

and

“n”

on

the

power

supply

board.

Measure

the

voltage

with

the

heat

off.

The

%

of

line

voltage

can

be

calculated

by:

(Measured

Voltage

/

Nominal

Voltage)

x

100

=

%

of

Nominal

Line

Voltage

Nameplate

Voltage

-

Nominal

Voltage

100

95

120

115

220

240

4/Calibration

and

Adjustments

CAUTION:

Use

the

Static

Control

Work

Station

(Part

No.

0175-2311-000)

to

help

ensure

that

static

charges

are

safely

conducted

to

ground.

The

Velos-

tat

material

is

conductive.

Do

not

place

electrically

powered

circuit

boards

on

it.

Note:

The

audio

alann

will

sound

for

about

2

sec-

onds

whenever

powering

up

the

unit.

Note:

Warm

up

the

unit

for

5

minutes

before

mak-

ing

these

adjustments.

A.

Control

Unit

Access

1..

Disconnect

the

power

cord

for

the

Infant

Warmer

System

from

the

wall

outlet.

2.

Remove

the

mounting

screws

for

the

back

panel.

B.

Power

Supply

Board Voltage

Checks

1.

Set

the

test

switch

(S1)

located

on

the

control

board

to

the

following

test

positions:

Switch

#1,#2,#4

Open

(“Off”)

Switch

#3

Closed

(“On")

2.

Connect

the

controller

assembly

to

the

power

source

(listed

voltage

+

10%),

and

switch

the

In-

fant

Warmer

“On”.

3.

Check

that

all

display

segments

are

“On”,

the

observation

lamp

is

“On”,

the

alarm

light

is

“On”,

the

heater

radiates

heat,

and-a

continuous

alarm

tone

sounds.

4.

Check

that

the

following

D.C.

voltages

are

pre-

sent

at

the

test

connector

(T1)

located

on

the

control

board.

Voltages

should

be

within

the

to-

lerances

specified:

TP7

Ground

(common)

TP3

(9.0

Vdc

ST.)

+9V

+

0.2V

(adjust

R4 on

P.S.

Bd.)

TP4

(5.0

Vde

LEDS)

+5V

+

0.2V

(replace

P.S.

Bd.)

TP5

(5.0

Vdc

ST.)

+5V

+

0.2V

(replace

P.S.

Bd.)

C.

Display

Brightness

Check

Note:

The

display

brightness

is

precalibrated

at

the

factory

and

should

only

require

adjustment

if

replac-

ing

a

component

on

the

display

board.

With

the

test

switches

set

as

follows:

Switch

#1,#2,#4

Open

(“Off”)

Switch

#3

Closed

(“On”)

Check

that

all

the

displays

are

lit

and

are

of

uniform

brightness.

If

the

displays

are

acceptable

proceed

to

Section

D.

If

the

displays

are

not

illuminated

adequately

proceed

with

the

adjustment

procedure.

Adjustment

Procedure

CAUTION:

The

back

panel

and

display

panel

may

drop

down

when

the

bottom

cover

mounting

screws

are

removed,

Be

sure

to

secure

the

panels

with

tape

before

disassembly.

1.

Set

the

test

switch

($1)

located

on

the

control

board

to

the

following

test

positions:

Switch

#1,#2,#4

Ореп

("ОН")

Switch

#3

Closed

(“On")

2.

Tape

the

display

panel and back

panel

to

the

top

cover.

3.

Remove

the

four

outside

corner

mounting

screws

from

the

bottom

of

the

display

panel.

Do

not

re-

move

the

two

inside

mounting

screws.

4.

Connect

a

digital

voltmeter

across

R10 located

on

the

bottom

edge

of

the

display

board.

5.

Adjust

R9 on

the

display

board

until

the

voltage

across

R10

is

3.30V

+

0.2V.

6.

Verify

that

all

segments

of

all

displays

are

lit

and

are

of

uniform

brightness.

D.

Alarm

Volume

Adjustment

Note:

The

alarm

volume

and

frequency

are

precalib-

rated

at

the

factory

and

should

only

require

adjust-

ment

if

replacing

a

component

on

the

control

board.

1.

With

the

test

switches

set

as

follows:

Switch

#1,#2,#4

Open

(“Off”)

Switch

#3

Closed

(“On”)

2.

Ensure

the

alarm

tone

and

volume

are

adequate.

Verify

that

the

audio

alarm

level

is

adequate

ina

lecation

with

a

background

noise

level

of

55

dBA

max.

If

the

audio

alarm

level

is

acceptable

go

to

step

E.

If

the

audio

alarm

level

is

unacceptable

proceed

with

the

adjustment

procedure.

Adjustment

Procedure

3.

Verify

the

frequency

output

at

U7

9

is

2

kHz

+

0.1

kHz.

Adjust

R38

on

the

control

board

as

re-

quired.

Note:

If

test

equipment

is

not

available

for

check-

ing

the

2

kHz

frequency,

adjust

R38

for

maximum

sound

level.

4.

Verify

that

R37

on

the

control

board

is

set

fully

CCW

(maximum

volume).

E.

Analog

to

Digital

Converter

(ADC)

Note:

The

following

resistance

values

are

available

on

the

Temperature

Simulator

and

the

switch

posi-

tions

are

listed

in

parentheses.

1.

Switch

the

power

switch

“Off”.

2.

Set

the

control

board

test

DIP

switch

(located

on

the

upper

edge)

to

the

calibration

positions

as

follows:

Switch.#1,

#2,

#3

Open

(“Off”)

Switch

#4

Closed

(“On”)

3.

Connect

a

resistance

of

5900

ohms

+

0.1%

(17)

to

the

patient

jack

connector.

4-1

4/Calibration

and

Adjustments

4.

Switch

the

power

switch

“On”

and

allow

the

3.

The

front

panel should

display

the

following:

unit

to

stabilize

for

5

minutes.

-

ーーーー

..

~

-

.

Pat.

Temp...

EEE

5.

Verify

that

the

ADC

counts

displayed

on

the

Cont.

Temp.

EEE

elapsed

time

display

is

1122

+

2

counts.

Slowly

Elapsed

Time

Running

in

Stop

Watch

Mode

adjust

R44

on

control

board

as

required.

6.

Input

resistance

values

into

patient

probe

con-

4.

Confirm

that

the

heat indicator

LED

on

the

con-

nector

and

verify

patient

temperature

readings

trol

board

is

lit.

are

within

tolerances

specified.

、 :

P

5.

Use

a

stop

watch

and

verify

that

elapsed

time

Resistance

Input

Patient

Temperature

display

is

accurate

within

+

1

second

per

min-

5900

ohms

+

0.1%

(17)

37.3

+

0.1

degrees

ute.

7060

ohms

+

0.1%

13,

33.0

=

0.1

4.

6190

ohms

+

0

1%

fay)

36.2

+

0.1

degrees

6.

After

approximately

3

minutes

and

20

seconds

4

h +

0.19

12

39.0

+

0.

(60

Hz

models)

or

approximately

4

minutes

(50

5496

ohms

»

62)

9.0

0.1

degrees

Hz

models)

a

warbling

alarm

which

cannot

be

si-

F.

Line

Voltage

Sensing

lenced

occurs.

1.

Use

a

DVM

and

measure

the

line

voltage

at

the

7.

The

heat

indicator

LED

on

the

control

circuit

wall

outlet.

board

(viewed

from

the

rear

of

unit)

should

be

2.

Calculate

the

displayed

%

variance

of

the

supply

off.

voltage

from

the

rated

nominal

voltage

using

the

8.

Switch

the

power

“Off”

for

the

Infant

Warmer

following

formula:

and

restore

the

test

switch

to

the

original

config-

(Actual

line

voltage

/

Nominal

Voltage)

x

100

=

uration

(all

switches

"Open").

Displayed

%

H.

Test

Loop

3.

Slowly

adjust

R3

on

power

supply

board

as

re-

Complete

Unit

Testing

quired

until

the

control

temperature

display

1.

Switch

the

power

“Off".

als

the

calculated

value

for

th

i:

It:

red,

catonlated

value

lor

ine

supply

voltage

2.

Place

the

test

switches

on

the

control

board

in

.

the

test

loop

position.

All

4

switches

Closed

Note:

For

domestic

115v

units

and

an

input

vol-

(“On”).

tage

of

115

volts

the

reading

on

the

control

tem-

3.

Switch

th

itch

“On"

perature

display

should

be

100

%

+

2%.

-

Switch

the

power

switc!

п.

4.

Switch

the

power

switch

“Off”.

4.

Verify

that

the

following

sequence

occurs:

G.

Triac

Safety

Circuit

Test

a.

For

the

first

second:

y

All

segments,

LEDS,

and

high-low

alternating

1.

Place

the

individual

test

switches

in

the

follow-

tone

audible

alarm

are

“On”.

ing

positions

b.

For the

、

High-low

alternating

tone

audible

alarm

“On”.

Switch

#1

Open

(“Off”)

000

Patient

display

—

60H

for

60

Hz

(50H

for

50

Hz)

Switch

#2,

#3,

#4

Closed

(“On”)

Elapsed

time

display

-

software

revision

number.

2.

Switch

the

Infant

Warmer

power

“On".

c.

The

unit

should

then

loop

in

the

following

order

until

the

power

is

removed.

Seven

Seg

Bar

Graph

Alarm

LEDs

Mode

LEDs

Heater

and

Display's

Segments

Lights

AN

Us

-

- 1.11

Probe

fail

Servo

“On"

AN

2's

2,12

Pat.

temp.

Servo

"off"

All

3’s

3,13

Sys.

fail

Servo

“On”

All

4’s

4,14

Heater

OFF

Manual

“Off”

All

5’s

5,15

Reset

timer

Manual

“On”

All

6's

6,16

Spare

LED

Manual

“Off”

All

7's

7

7,17

Al

"Off"

Apgar

“On”

All

3's

8,18

All

"Off"

Apgar

“Off”

All

9's

9,19

AN

“Off”

Apgar

"On"

All

0’s

10,20

Al

"Off"

All

“Off" "Off"

All

“Off"

АП

“Ой”

Al

"Off"

All

“Off”

4-2

Ohmeda 3000 User manual

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