Mechanical Description; General; Front Panel; Rear Panel - Datron 1062 Service Handbook

13
SECTION
2
MECHANICAL
DESCRIPTION
2.1
GENERAL
The 1061
has been
designed
to be either rack
mounted
in a
standard
19"
rack OVz" (2U) height
re-
quired) or
bench
top/portable with integral
tilt
stand.
An
exploded view
of the
instrument
is
shown
in
Fig
2.1.
2.2
FRONT
PANEL
The
front panel incorporates the
signal
input termin-
als,
range, function,
mode, keyboard, compute and power
switches and
a
numeric/legend
gas
discharge display.
2.3
REAR PANEL
The
rear
panel incorporates the mains supply,
power
input socket and
fuses, digital
and
analog output
sockets,
rear
and
ratio signal
input sockets, rear/front panel
signal
input
selection switch, run/calibrate keyswitch,
calibration
interval
(error) select
switch and current option
fuse.
2.4
EXTERNAL CONSTRUCTION
A
screen printed
key designation overlay adheres to
the front panel retaining the
polarising
filter in
front
of the
display.
Both
the front
and
rear panels are held together
by
two
side extrusions
running from
front
to rear.
These
side extrusions provide both
slots for
the handles
or rack
mounting
'ears'
and locating points for the structural
foam
covers.
The bottom
cover
is
fitted
with the
tilt-
stand,
rubber
feet
and instruction card.
Earth screening
of the covers and guarding
is
provided
by aluminium
plates,
heat-staked to the inside
of the covers with electrical
connections
made by
spring contacts.
2.5
INTERNAL CONSTRUCTION
An
internal chassis
is
constructed
from
five printed
circuit
boards, held together
by connectors
at
each corner
and held
rigid
by two
inner
aluminium
shields fixed hori-
zontally
on
the instrument's centre
line
running
from
front to
rear.
Input terminals,
switches and
display are
mounted
on
the front printed circuit
board
(pcb)
and
the
power
supply on the
rear
pcb.
The two
side
and centre
pcb's are used for
interconnections between
the
main
circuit boards.
All
the
main
circuit
boards
are
mounted on
the inner
shields
with
hinges
and quick
release
fasteners with
flexible
connections
to allow operation
in
the 'hinged-up' position.
The Analog
output
circuitry
is
fixed
on
to
the
rear
pcb
of
the
chassis
and
the
Ratio/Rear Input
circuitry
on
to the
rear panel.
The
options
are
mechanically
fitted
and
require
no
soldering.
The
chassis
is
mounted
on
to the side
extrusions with
nylon screws, spacers
and
an
insulation
sheet to ensure
that the
'electrical spacings' of the BSI,
UL
and
VDE
specifications are achieved.