Manual Operation; Set Voltage - TTI QL Serie Manual De Instrucciones

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

The left-hand display shows the set voltage to a resolution of 1mV, except when the instrument is in
constant current (CI) mode. In CI mode the actual output voltage (which will be less than the set
voltage) is shown and the display resolution is 10mV; the least significant digit (1mV resolution) is
always displayed as a zero.
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 display shows 0·000; a new voltage is then entered (e.g. 12·345V is
entered as 1, 2, ·, 3, 4, 5) and confirmed by OK. The position of the decimal point in the display is
fixed to reduce the risk of entering a wrong value. As a consequence, and to avoid the need to enter
leading zeroes (e.g. 2·345V is entered as 2, ·, 3, 4, 5, OK), numbers to the left of the decimal point
are shown slightly differently to the numbers to the right of the decimal point during number entry;
this is self-evident during number entry.
The minimum voltage setting is 0·000V; the maximum setting is 35·000V (15·000V on the 15V/5A
range).
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; pressing OK immediately after SET V (while
the display shows 0·000V) will set 0·000V.
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 twice; 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 key and
the JOG indicator under the digit that was last jogged will flash. Whilst the V key 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 flashing JOG indicator. The output immediately
follows the setting, i.e. no OK is required. If the output goes into constant current mode (indicated by
the CI indicator flashing) the left-hand display shows actual voltage not set voltage. If JOG SET V is
selected the JOG indicator under the selected digit will flash at half speed ('lazy' flash). To observe
the effect of jogging the set voltage it will be necessary to either turn the output off (so that the
display permanently shows the set voltage) or to press
VIEW V/I LIMITS which causes the set voltage to be displayed until 3 seconds after movement of the
jog control ceases.
Note that in constant current mode the actual voltage is measured and displayed to only 10mV
resolution; the 1mV digit permanently displays zero.
Further details on the jog control can be found in the Initial Operation chapter.
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