Using Voltage Span
The VOLTAGE SPAN (V-Span) capability allows the end-stop values of the VOLTAGE controls to be
redefined by the user such that the controls operate within a specific, narrower, voltage range. This
not only has the advantage of protecting against the accidental application to the load of voltages
outside of the range, but also provides high-resolution analog control over the specified voltage
range using the full 300º rotation of the voltage controls.
Because turning V-Span on will always change the output voltage, it can only be enabled or
cancelled with the output off. If attempts are made to enable or cancel V-Span with the output on,
the display will briefly show the message
To set new values for V
The lower voltage limit is defined by using the MAIN and FINE VOLTAGE controls to set exactly the
required value; the V
and the right-hand side (mA) display shows
short press (<1 second) of the V
same way using the VOLTAGE controls and the V
The limits can be set in any order and to any value within the output range of the instrument but V-
Span can only be turned on with the ENABLE key if V
the message
When V-Span is enabled, the range of the MAIN VOLTAGE control is exactly V
FINE control is set at its mid-point, marked on the panel with a • . The FINE control itself can be
usefully used to give an additional fine adjustment of ±1% (of the voltage span). Note, however, that
if V
is set close to 250V the fine control cannot adjust the voltage above 250.0V.
max
The V-Span status at power on is the same as at last power off.
or V
min
max
key is then held pressed until the left-hand side (V) display stops flashing
min
min
Set Err
is briefly displayed and the V-Span function is not implemented.
V-Span is turned on or off with the ENABLE key. The
ENABLE lamp is lit when V-Span is selected. The
factory default is V
turn oFF
to prompt the user to turn the output off.
the V-Span function must be off (cancelled).
Set
. The setting can be VIEWed at any time by a
key. The upper voltage limit is set and VIEWed in exactly the
key.
max
max
= 3V, V
= 5V
min
max
≥ (V
+ 0.1V); if this condition is not met,
min
to V
when the
min
max
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