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OTHER FEATURES
In
addition
to
the
functions previously mentioned,
the
DN27A
has
several note-worthy features.
The
main p.c.b houses
a
relay and associated drive
network which performs
two
important functions.
1)
The
output socket
is
isolated
from the
equaliser
until power
is
switched
on and all
internal power
rail
are stable.
This
"delayed turn-on" prevents
D.C. or
transients caused
by
powering-up
from being
transmitte
to
successive pieces
of
equipment;
2)
If,
during operation,
a
loss of power
to or
power
related failure
in
the
DN27A should occur,
the input
i
electronically connected directly
to
the output, provi
"total system bypass".
Subsequently,
loss of power do
not cause
complete
loss of signal; this may save
considerable problems
in
a
"live" situation.
The
DN27A power supply includes output voltage regulat
which
are
designed
to
shut-down
if
over-heated
and are
current-limiting.
The
supply rails are
of
higher volt
than used
in
previous
units, and allow
an
output clipp
level
of
+23dBm
as
well
as an
extremely good dynamic
r
Also
provided
on
the
main p.c.b
is
a
12
terminal conne
(via
which input and output lines travel) permitting
e
addition
of
line
balancing
on an
optional plug
in
boar
Power rails are also present
on
this connector achievi
maximum flexibility,
i.e.
a
plug-in p.c.b could house
transformer and/or electronic balancing,
and
could als
include such facilities
as
active filters.
(When no
s
option
is
used
a
dummy p.c.b
is
plugged-in
to
complete
input and output lines.)
As
mentioned earlier,
an
earth-lift switch
is
situated
on
the rear panel.
Activating this switch connects/
disconnects signal gound to/from
the
mains
and
chassis
earth.
Use of this
feature mav Drove invaluable
if
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