A-4
CONSTANT VOLTAGE (CV) TESTS
CV Setup.
For all CV tests set the output current at full rated
output to assure CV operation. The onset of constant current
can cause a drop in output volta
e, increased ripple, and
other performance chan
es not properl
ascribed to the con-
stant volta
e operation of the suppl
.
Load Regulation (Load Effect)
Definition:
CV Load re
ulation is the chan
e in the stead
state value of dc output volta
e due to a chan
e in load resis-
tance from open circuit to full load or from full load to open cir-
cuit.
Test Parameters:
Measured Variable: Output Volta
e
Expected Results: Less than 0.01% plus 2 mV
Test Procedure:
a. Connect the test equipment as shown in Fi
ure A-4.
Operate the electronic load in constant current mode
and set its current to the full rated value of the power
suppl
(6 A for E3614A, 3 A for E3615A, 1.7 A for
E3616A and 1 A for E3617A).
b. Turn the suppl
's power on and turn CURRENT con-
trol full
clockwise.
c. Turn up output volta
e to the full rated value (8 V for
E3614A, 20 V for E3615A, 35 V for E3616A and 60 V
for E3617A) as read on the di
ital voltmeter.
d. Record the output volta
e at the di
ital voltmeter.
e. Operate the electronic load in open(input off) mode.
f. When the readin
settles, record the output volta
e on
the di
ital voltmeter a
ain. Check that the two recorded
readin
s differ less than 0.01% of output volta
e plus 2
mV.
Fi
ure A-4. Basic Test Setup
Line Regulation (Source Effect)
Definition:
Line re
ulation is the chan
e in the stead
state
value of dc output volta
e due to a chan
e in ac input volta
e
from a minimum to a maximum value(±10% of nominal volt-
a
e).
Test Parameter:
Measured Variable: Output Volta
e
Expected Results: Less than 0.01% plus 2 mV
Test Procedure:
a. Connect the test equipment as shown in Fi
ure A-4.
Operate the electronic load in constant current mode
and set its current to the full rated value of the power
suppl
.
b. Connect the suppl
to the ac power line throu
h a
variable autotransformer which is set for low line volt-
a
e(104 Vac for nominal 115 Vac, 90 Vac for nominal
100 Vac, and 207 Vac for nominal 230 Vac).
c. Turn the suppl
's power on and turn CURRENT con-
trol full
clockwise.
d. Adjust VOLTAGE control until the front panel VOLTS
displa
indicates exactl
the maximum rated output
volta
e.
e. Record volta
e indicated on the di
ital voltmeter.
f. Adjust autotransformer to hi
h line volta
e(127 Vac
for nominal 115 Vac, 110 Vac for nominal 100 Vac,
and 253 Vac for nominal 230 Vac).
. When the readin
settles, record the output volta
e
a
ain. Check that the two recorded readin
s differ
less than 0.01% of output volta
e plus 2 mV.
Load Transient Response Time
Definition :
This is the time for the output volta
e to return to
within a specified band around its volta
e followin
a chan
e
from full load to half load or half load to full load.
Test Parameter:
Measured Variable: Output Volta
e Transients
Expected Results: Less than 50 usec (at 15 mV from
base line)
Test Procedure:
a. Connect the test equipment as shown in Fi
ure A-4,
but replace the DVM with the oscilloscope. Operate
the electronic load in constant current mode.
b. Turn the suppl
's power on and turn CURRENT con-
trol full
clockwise.
c. Turn up output volta
e to the full rated value.
d. Set the electronic load to transient operation mode
between one half of suppl
's full rated value and sup-
pl
's full rated value at a 1 KHz rate with 50% dut
c
cle.
e. Set the oscilloscope for ac couplin
, internal s
nc and
lock on either the positive or ne
ative load transient.
f. Adjust the oscilloscope to displa
transients as in Fi
-
ure A-5.
. Check that the pulse width of the transients at 15 mV
from the base line is no more than 50 usec as shown.
+-
+S
OUT
-S
+- +-
CV
+-
CC
A1 A2 A3 A4 A5VREF
ELECTRONIC
LOAD
+
-
DIGITAL
VOLTMETER
Rs
-
+
TO
DVM
POWER SUPPLY
UNDER TEST
MASTER
LOCAL
SLAVE
REMOTE
Model
Rs
E3614A, 15A, 16A
E3617A
0.1 ohm 0.1% 10W
1 ohm 1% 5W
M/S 1 M/S 2
CV CC
SENSE
