Delta Elektronika SM 120-50, Manual, Page: 6 / 21

GENERAL SM6000
6 / 21 DELTA ELEKTRONIKA B.V. rev. Nov. 2020
3 GENERAL
3.1 DC OUTPUT

The SM15-400, SM30-200, SM45-140, SM60-100, SM70-90,
SM120-50, SM300-20 and SM600-10 can either be used as a
constant DC voltage source with current limiting or as a
constant DC current source with voltage limiting.

The change of mode occurs sharply at the crossing of the
voltage and current settings. Figure 3 - 1 shows the DC
output ranges.

DISPLAY CV/CC SETTINGS FUNCTION
The settings of the voltage and current control (also when
programmed) can be observed on the front panel meters by
pressing the Display CV/CC Settings button. This allows the
current limit to be set when operating in the CV mode without
shorting the output terminals, and the voltage limit to be set
when operating in the CC mode without opening the load
leads.

OVERLOAD PROTECTION
The power supply is fully protected against all overload
conditions, including short circuit.
3.2 AC INPUT VOLTAGE

The power supplies have a wide AC input voltage range.

The unit needs a 3 phase input voltage, but no neutral
connection is required.

The unit only operates on three phases. In case of Phase
Loss , the ACF-status (AC Fail) will be high, the ACF-LED will
light and the output shuts down after a few seconds.
3.3 AC INPUT CURRENT

The unit has active power factor correction (PFC). The input
current will therefore almost be a sine wave. This means that
the RMS-value and the harmonic distortion of the AC input
current will be relatively low.

The peak inrush current is electronically limited. Switching on
and off repeatedly will not result in excessive currents like
with NTC circuits.
3.4 STANDBY AC INPUT POWER

The unit consumes very little power when in standby. This
makes it possible to leave the AC input power on when the
output is disabled using the Output On/Off push button on
front panel or the Remote ShutDown input (pin 5 on
connector CON E on the rear panel).
3.5 EFFICIENCY

The efficiency is very high and constant over a wide DC
output current range.

High efficiency means low power loss and low heat
generation.
3.6 CV REGULATION

The specified CV-load regulation value is measured directly
on the DC power terminals. This is because at high current, a
few cm of cable can have a voltage drop of several mV.
3.7 CC REGULATION

For accurate CC-load regulation, do not use external voltage
sensing.

A voltage between S- and minus output will create an error of
about 0.04 % per volt.

A voltage between S+ and + is not critical. The CC-stability is
also affected by external voltage sensing.

Note: when the unit operates in CC-mode, the DCF-LED will
be on. When the unit is in CC-mode most of the time, it is
possible to disable the LED with DIP switch 3 on SW1 (rear
panel).
3.8 RIPPLE & NOISE

The DC output ripple is very low with almost no spikes. The
specified ripple voltage is measured directly on the DC power
fig 3 - 1
DC Output voltages and currents.
Every point in hatched area can be used
fig 3 - 3
Measuring ripple voltage
RIGHT!
fig 3 - 2
Measuring ripple voltage
WRONG!