Chapter 3
3.1 Putting into operation
Prior to putting the instrument into operation, a threepole power cord must be connected to
the power barrier strip 'TB1' on the rear panel. The gauge of the power cord is to be selected
so, that the cord can carry 20A at 230V or 40A at 115V.
The phase (Ph) and common (N) are connected to the AC-AC terminals (TB1-1 and 3).
Ground (E) is wired to the terminal G (TB1-2) or the grounding screw. As soon as the the
power switch is positioned 'ON', the instrument is ready for operation. The warm-up time
required to achieve the stability specification being negligible at room temperature.
Note: The outputs of the power source should not be connected to AC- sources, DC- sources
with reverse polarity or DC-sources with higher voltage than 1.2 x Unominal If such an operating
mode is inevitable (e.g. charging batteries, paralleling power sources or working with heavy
inductive loads), the customer must assure proper safety measures ( e.g. OR-ing diodes, fuses
etc.).
3.2 Constant voltage operation with current limiting
This mode of operation is reached, when the LED-indicator 'CV' lights up. Because of the
high stability of ATLAS, it is possible to adjust accurately the output voltage to several
decades. For this, an adequate digital voltmeter should be used. The local adjustment is
performed using the voltage control knob 'VOLTAGE'.
The adjustment to the desired and limited current is achieved by short-circuiting the output
and using the current limiting control knob while reading the display.
3.3 Constant current operation with voltage limiting
This mode of operation is reached when the LED-indicator 'CC' lights up. The hight of the
constant current is locally adjusted using the current control knob 'CURRENT'. The lower
limit for the constant current operation is 100mA. It is important to be careful, particularly
when working with small output currents, since the charging or discharging currents of the
output capacitor affects the constant current, depending on the charging condition of the
output capacitor under dynamic loading condition.
The output voltage to be maximum limited is adjusted by using the voltage control knob and
reading the display.
3.4 Remote sensing
Unavoidable voltage drops across the output terminals and the load lines can be compensated
by including sensing leads in conjunction with the load. Noting however, that a voltage drop
of 0,5V for each lead must not be exceeded.
Circuit arrangement:
1. Open links between +V and +S, -V and -S respectively.
2. Connect the load (±V), and sensing (±S) leads, and connect them to the load
connections (same polarities together).
Note:
When operating the power supply with the sensing leads opened or interrupted, rated data can
no longer be maintained. However, instruments are protected so that no damage can be result
even with an S-lead open.
Atlas 2000
Page 10 von 26 ISSUE 07/05
