Ccbd-cc – Vicor Constant Current (CC) Demonstration Board User Manual
Page 10
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Page 10
3.4 CC Demonstration Board with an Electronic / Resistive Load
1.
Make sure that the power is removed from the unit prior to making adjustment.
2.
Connect DMM in series with the electronic load. Make sure DMM can handle the
maximum PRM output current then set it to read DC current.
3.
Set the Electronic Load to constant resistance mode of 0.16 Siemens.
4.
Verify proper DMM and electronic load connections to the CC board output.
5.
Connect an oscilloscope to the test point provided to monitor output voltage. Remove the
plastic cover of the scope probe and position it in the test jack (J02). The oscilloscope is
now referenced to the –OUT ground. Be careful not to create a ground loop by
connecting any other probes to the –IN. Shorting the –IN and –OUT of the PRM will
defeat the PRM current limit feature as the current shunt is in this path. Please refer to the
measurement precaution section for more details.
6.
Turn on a fan if necessary.
7.
Turn on the electronic load.
8.
Raise the DC input voltage to the nominal value of 48 V as indicated on the
Observe that turning the potentiometer V
REF
(R10) clockwise increases the voltage
measured on test point V
REF
resulting output current with a max error of 2% as
shown in Figure 10.
Figure 9
CC Electronic / Resistive Load
Figure 10
V
REF
vs. I
OUT
PRM Error Margin
DC
+
+
-
-
CCBD-CC
+
-
Electronic Load
+OUT
DMM
Measuring
Output Current
Set to Constant Current mode
DMM
Measuring Voltage V
REF
using test point TP5
–OUT
+IN
–IN
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
0.2
0.7
1.2
1.7
2.2
2.7
3.2
3.7
4.2
4.7
5.2
5.7
6.2
V
REF
(V)
P
e
rc
e
n
ta
g
e
o
f
E
rr
o
r
(
%
)
V
REF
(
typ.)
vs. I
OUT