Operating Routines; Dc Voltage Outputs; Ac Voltage Outputs - Datron 4708 User Handbook Manual

Operating Routines
The
following operating routines are
subdivided
into
two main
types:
•
Standard Operating Sequences
•
Additional Facilities
Standard Operating
Sequences
There
are
many common
elements
in
the selection routines for
both Voltage
and
Current operation.
The
diagram opposite
shows
the general sequence of operations.
It
should
be used
as
the basis
of any operating procedure,
in
conjunction with
the
individual selections detailed in the
following pages.
DC
Voltage Outputs
There
are
two
overlapping voltage
states.
The
20V
overlap
allows
±10%
adjustment about the
typical full
range value of
lOOV
without changing
state.
In the
Low
voltage
state,
the output
may
be switched
ON
directly but to transfer
from
Low
to
High Voltage
state,
deliver-
ate
user-actions are required.
N.B.
The 4708
switches
its
output voltage
OFF
every time
the
lOOOV
RANGE
is
selected
and
when lOOOV
RANGE
polarity
is
reversed.
Low
Voltage
selections (up to
lllOV).
Use
the general
sequence:
At
operation
(3)
:
Select
DC.
At
operation
(4)
and
(5)
:
No
Remote Sense on lOOp;
Im,
10m
and
100m
ranges.
High
Voltage
selections
(above ±110V). Use
the general
sequence:
At
operation
(3)
:
Select
DC
At
operation
(9)
:
RANGE
LED
flashes for
selec-
tions
above
±110V
At
operation
(1
1)
:
Audible warning
-
5 pulses/sec
for 3 secs.
:
After 3 second
warning
-
4708
switches
OUTPUT
ON.
Whilst
OUTPUT ON
-
Audible reminder
pulses at
approx.
1
sec. intervals,
and
RANGE
LED
continues
flashing.
If
OUTPUT
OFF
or
ON
switching
is
attempted during
the 3
sec.
delay the
4708
reverts
to
OUTPUT
OFF.
Transfer
into
High Voitage State with
OUTPUT
ON.
By
changing
RANGE:
- the
OUTPUT
is
switched
OFF,
and
the selected
RANGE
LED
flashes.
User
reselects
OUTPUT
ON:
-
3
sec
audible
warning
-
4708
switches
OUTPUT ON
-
Audible reminder whilst
OUTPUT ON
-
RANGE
LED
flashing
By
use of
1
4-
keys
in
lOOV
or
lOOOV
range:
-
OUTPUT
remains
ON
at
previous voltage
-
OUTPUT
display
shows
selected
(High Voltage)
value
-
RANGE
and
OUTPUT ON
LEDs
flash.
User
reselects
OUTPUT
ON:
-
3
sec
audible
warning
-
4708
increases
OUTPUT
voltage
to
OUTPUT
display
value
-
Audible reminder
whilst in
High
Voltage
state
-
RANGE
LED
flashing
-OUTPUT
ON
LED
lit
continuously
Transfer out
of
High Voltage
state
with
OUTPUT ON
By
pressing
OUTPUT OFF
key:
ON+
or
ON-
LED
remains
lit
until
the
OUTPUT
Volt-
age
has
decayed
into
Low
Voltage
State
(Approx.
1
sec
from lOOOV).
By
use of
1 4
keys or
by changing
RANGE
down:
Transfer
to
Low
Voltage
State
is
automatic
when
the
OUTPUT
Voltage
faUs
below 90V.
-
RANGE
LED
stops flashing
-
stays
lit
-
OUTPUT ON LED
stays
lit
-
Audible reminder
is
silent
Changing
voltage
state
when
In
Error
or
Offset
Mode
For
safety reasons, the thresholds are
always
defined with
respect to
voltage levels at the
OUTPUT
terminals. Therefore,
if
the
instrument
is
in
Error or Offset
mode,
the threshold indi-
cations
may
not coincide with
1
lOV
and
90V
on
the
OUTPUT
display.
AC
Voltage Outputs
Zero Output
Zero
AC
Voltage output from
the
4708 can be
obtained only by
pressing the
Zero
key. Internal relay contacts short
1+ and
I,
and
Hi
to
Lo.
Increment from Zero
The
smallest
AC
output available
on any
range
is
9%
of
full
range, so
any attempt
to
reduce the output
below
9%
is
refused.
Thus
the smallest
possible
increment from Zero
is
to
1
0%
of
full
range, using the appropriate key (any
key
to the right
of
this
would
attempt
to
increment
to
1%
or
less,
and be
refused.
4-7