Ericsson DIALOG Parts list manual

·.
DIALOG
Technical Description
6/DLG
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CONTENTS
1. Introduction
3
2.
General
4
3.
Desi gn 6
3.1
Base plate
7
3.2 Ring
er
8
3.3
Transmission unit
10
3.4
Dial unit
12
3.5
Instrument case
13
3.6 Cords
15
3.7 Handset
16
3.8 Wall
terminal box
19
4. Description of the transmission regulation device
21
5. Transmission properties
24
6. Dismantling and reassembly during maintenance
26
7.
Maintenan ce
31
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1. INTRODUCTION
Ever since its foundation in 1876 L M Ericsson has designed and
produced telephone instruments of different versions. One link in
the chain of standard telephone instruments is Dialog which incor-
porates the latest research techniques , new construction materials
and the results of our wide experien ce as designers and manufac-
turers . Dial og is attractive in appearance and has ex ce llent tech-
nical qualities. Furthermore, the technical and desi gn aspects have
been matched to the maintenance requirements .
This description refers to the desk version of Dialog but is also
valid for the wall version as the me c hanical design and technical
f ea tures follow the same principles. The transmission properti es
described are g iven for Dialog with automatic transmission regu-
lation.
3
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4
2. GENERAL
Dialog, equipped with dial, is intended for connection to automatic
main exchanges, private automatic exchanges and private automatic
branch exchanges (fig. 1).
Fig. 1
Dialog
In designing this instrument, the aim has been to make telephoning,
i.e., the dialling and handling of the instrument. as comfortable as
possible. and to enable the instrument to be easily carr ied (fig. 2).
With this aim in mind, the most attractive design has been created
as a result of close cooperation between engineers and industrial
designers.
This means among other things that the instrument constitutes a
single. compact design, attractive from all angles (fig. 3a-3c),
Fig. 2
Dialog
is easy
to carry
'I ·
1·
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Fig. 3 a
Dialog
front
view
The design of the instrument case and handset , the mechanical
build-up. as well as the circuit. are completely new. Tw o fa cto rs
have contributed to these alterations. First. the utilization of
new
materials and high-quality electrical components available,
and. secondly. the application of previous experien c e.
Fi g . 3 b
Dial og
sid e
vi
ew
Fi g. 3 c
Di
al og
re ar
vi ew
-
5
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6
3. DESIGN
As shown in fig. 4, Dialog has seven main parts, namely
Handset with cord
Instrument cord with wall-terminal box
Instrument case
Base plate
Dial unit
Transmission unit
Ringer unit
Fig. 4
The main
parts of
Dialog
As the ringer unit, transmission unit and dial unit are keyed into
the base plate no screws are required.
The instrument and handset cord conductors are mechanically
connected to screw terminals on the transmission unit. The
instrument case is fixed to the internal parts by means of only
one
screw, well located for the repairman and concealed from the
subscriber (fig. 5).
Each unit has its own function and can be replaced by an identical
unit, regardless of the other units. The assembly method enables
a complete telephone instrument to be built up of a few units , each
of which comprises several components. From the maintenance
point of view this is a most valuable method of design, since
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Fig. 5
Onl 'Y one
screw
Ca se
3.1 Base pl ate
Fig. 6
The scr ew is well located
for the repairman
maintenance in the field can be carried out by semi-skilled staff,
with a minimum of tools and instruments. Only a screwdriver is
required to replace any unit (fig. 6). When necessary, repla c ed
units can be repaired at a central workshop where qualified staff,
tools, and instruments are available.
The DIALOG-case and handset are moulded in acrylate butadiene
styrene (ABS), and are manufactured in eight colours. The dyes
or pigments used for colouring have been chosen c arefully to
ensure colour-fastness. The plastic material offers an o ptimum
of hi gh impact- and scratch resistance and can easil y withstand
the effects of falling from one meter on to a hardwood floor .
The handset cradle is designed so that line disconnection is ensured
even when the handset is lightly or carelessly replaced.
Under the cradle and at a convenient distance from the handset ,
there is a carrying grip to facilitate the moving of the telephone
instrument. This execution is far superior to su ch t ype s wher e
extra arrangements have been added to the ca-se afterwards or
where metal handles have been fixed to the case by means of
screws.
The frame for the subs c riber number is fixed to the front of the
case, allowing both subscriber number and routing number , or
nam e of exchange, to be typed.
The base plate, shown in fig. 7 is made of sheet steel, zinc-electro-
plated with yellow c hromate coating and laquered . Unlike
L M Ericsson~ s e arlier telephone instruments, the base plate of
this instrument has raised edges to ensure hi gh mechanical
stability. The various units can then be keyed into the base plate
without affecting its mechanical strength, despite the fact that thin
metal is used. The base plate has four non-slip feet of neopren,
a durable, migration-free synthetic rubber, which hold the instru-
ment steady during dialling .
The slots in the base plate permit re g ulation of the ringer and
supply locking support for the various units to be mounted. At
7
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3.2 Ringer
8
the cord inlet in the base plate, a hole has been made in the raised
edge. The cords, which can thereby be rem oved one at a time,
lock each other and ensure a tight packing.
Fig. 7
The base
plate from
above
The ringer mechanism (fig. 8 and 9) is mounted on a plate (1)
provided with three tabs which are inserted in slots in the base
plate. In addition there is a hole in the centre cf the ringer
mechanism plate in which a projecting stud on the base plate fits
when the ringer mechanism has been correctly l oca ted.
Fig. 8
The bell
unit
The ringer is connected to the screw terminals of the trans- ·
mission unit by means of two PVC insulat ed conductors . eq uipp ed
with cable lugs. The ringer is of the polariz ed type with a single
winding (3) and a small AlNiCo permanent magnet (2). Th e flux
generated by the permanent magnet and the flux. or iginatin g from
the ringing current. is superimposed only in the ''air gap' ', which
gives maximum signalling efficiency. The "air gap" is easy to
adjust and the coil is replaceable.
The coil former is made of Formaldehyde-plastic and wound with
copper wire. insulated by shellac.
All the iron parts are zinc-electroplated with yellow cro mate
coating and laquered.
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Fig, 9
The bell
unit in
parts
The gongs (4) are of sheet brass and the fixing holes are eccentric
to permit easy adjustment for maximum sound intensity . Two
pillars are riveted to the ringer-plate in order to support the
gongs and the resonator cups (5).
The ringer produces a pleasant sound , penetrating even to people
with impaired hearing (limitation of hearing generally starts at
high frequencies). These important properties are obtained as
a result of the gongs having different pitches, and the subharmoni cs
of the signal being amplified by Helmholtz resonators (5).
The Ringer Output Spectrum is shown in fig. 10.
The ringer can be equipped with sound regulation if required. By
reducing the movement of the bar by means of a tag under the in-
strument. the sound intensity of the ringer can easily be altered -
continuous regulation from full output (74 dBa) to the soft signal of
a buzzer (45 dBa).
The impedance at 25 Hz (c/ s). with a 1 µ F capacitor in series
with the bell, is 4 500 Ohm. and at 800 Hz (c/ s) 36 000 Ohm.
9
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