Manual Operation
New users should first read the Initial Operation chapter which describes the operating principles
of the keypad and rotary jog control.
Set Voltage
With the
output off, the standard status display shows the set voltage;
Limits
shows as a
reminder beside
OUTPUT OFF
in the top line of the display. With the output ON the mode
changes to
CV
(constant voltage) or
CI
(constant current), depending on the set current limit and
load conditions, and the display shows the actual output voltage (measured at the sense point);
note that in CI mode the actual output voltage will be less than the set voltage. Both the set and
actual voltage are shown to a resolution of 1mV. If the set voltage and load conditions cause the
instrument to operate outside its guaranteed power range the display will show
UNREG
(unregulated) and the actual output voltage will again be less than the set voltage.
The voltage can be set directly from the numeric keypad: press the NUMERIC SET V key, enter
the new value using the numeric keys and confirm by pressing OK. The broad principles of
keypad entry are explained in the Initial Operation chapter, which should be read by new users.
When SET V is pressed the VOLTS display changes to show the present set value in a smaller
font, with the message
Enter V or ESC
below it, and the OK lamp starts flashing. The new
voltage is then entered from the keyboard, e.g. 12·345V is entered as 1, 2,
·
, 3, 4, 5. As it is
entered it is displayed directly below the present setting, replacing the prompt message.
The minimum voltage setting is 0·000V; the maximum setting is 60·000V.
Pressing OK at any point will set the voltage entered with any remaining digits set to zero,
e.g. 1, 2,
·
, 3, OK will set 12·300V; 1, OK will set 1·000V. When OK is pressed the set voltage is
changed and the display reverts to the standard status mode.
Pressing ESCAPE at any time during the sequence, or making no further key press within
10 seconds of the previous one will cause the display to return to its original reading before
SET V was pressed.
Entering a voltage outside the range maximum (including trying to enter 3 digits before the
decimal point) or trying to enter more than 5 digits will cause the buzzer to beep; the last key
entry will be ignored.
The voltage can also be set using the Jog control. Pressing JOG SET V will illuminate the V JOG
SET lamp and the VOLTS display will again change to two lines. With the output ON the top line
continues to show the actual output, but the additional lower display now shows the present
Limits
value; in the lower display, the JOG indicator ( ) is positioned under the digit that was
last jogged. Whilst the V SET lamp is lit, each further press will move the JOG indicator one
digit to the left; the selection 'wraps round' such that when the largest value of jog increment has
been reached the next press returns it to the lowest. The default position at power-up is under
the LSD, i.e. the lowest jog increment is selected. The jog steps that can be selected are 1mV,
10mV and 100mV.
With jog enabled the output voltage can be incremented or decremented with the rotary jog
control with a step resolution indicated by the position of the JOG indicator. The output
immediately follows the setting, i.e. no OK is required. In CV (constant voltage) mode the actual
output voltage shown in the upper display line will follow the set voltage being ‘Jogged’ in the
lower display; however, if the output goes into constant current mode (indicated by the CV status
message being replaced by CI) the upper display, showing actual voltage, will show a value
which is less than the set voltage.
Note that the dual display during JOG SET V is primarily of use if the output is ON; with the
output off both lines of the display show the
Limits
value and change simultaneously as the
voltage is jogged.
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