Chapter 2 Constant Voltage Tests
RIGOL
DP1308A Performance Verification Manual
2-3
CV Load Adjustment Rate (CV Load Effect)
CV load adjustment rate, a static specification, is used to test the output voltage
variation of the power supply caused by the load effect under constant voltage (CV).
During the measurement, the measurement error caused by the output terminal
should be taken into consideration. Figure 2-2 is the schematic diagram of the output
terminal of the power supply. As the output terminal is metallic conductor and has a
certain contact resistance
r
∆
, when the output current of the power supply is
I
, the
terminal voltage is
I
r
Ve
×
∆
=
. Therefore, the voltage test point is generally located
at A to reduce the error caused by the terminal voltage. Besides, the contact
resistance generated by this terminal and the power output line and voltage feedback
line inside the instrument would cause an offset (U
offset
) of less than 2mV.
Figure 2-2 Output Terminal
Assume that the power supply currently works in CV mode, the output voltage for no
load is U
0
and for full
load is U
1
,
the load adjustment rate is defined as:
Load Adjustment Rate=
%
100
Voltage
Output
Rated
|
|
0
1
×
−
−
offset
U
U
U
(2-1)
1.
Turn off DP1308A. Connect DP1308A, AC source, electronic load and multimeter
according to Figure 2-1. Note that the measurement probe or clip of the
multimeter must be connected to A in Figure 2-2.
2.
Turn on the AC source and set its voltage to the AC line voltage.
