Usin
your Pro
rammable Power Supply 5 - 9
Current sink characteristics PM2831/32
The followin
fi
ure
ives an example that shows the sink characteristics of the
power supply. The power supply is used as a constant current load for an external
source, where the sink capability of the power supply is demonstrated.
Overvolta
e protection is set to the maximum level and overcurrent protection is
disabled.
The power supply and the external source (this may be another power supply) are
set to the same output volta
e: V
source
. There is no current flow yet.
The current settin
s are: I
set_source
> I
set_load
.
The volta
e settin
of the load is
radually decreased by pressin
the -V+ key. The
chan
e of the actual volta
e settin
is not visible on the display, because the display
will show the constant volta
e applied by the external source. But the volta
e
settin
of the power supply can be made visible at any moment by pressin
the V
key. When the settin
approaches V
source
- 0.6V, the power supply switches to the
constant current (CC) mode at the level of -I
set_load
. In this situation the ne
ative
current of the power supply tracks the pro
rammed (positive) value I
set_load
.
The volta
e can be raised by pressin
the -V+ key. When the settin
approaches
V
source
- 0.6V + 0.15V, the power supply will exit constant current mode and return
to the constant volta
e mode @ 0A.
Iset_load
−A +A
source
(External Constant
Voltage Source)
source
−0.6V+0.15V
V
ST6841
0
V
V
−0.6V
source
V
Fi
ure 5.5.3 Current sink characteristics
