Constant Voltage Load Regulation Test Setup - HP 6269B Operator’s, Organizational, Direct Support And General Support Maintenance Manua L

Figure 5-2. Constant Voltage Load Regulation
Test Setup
correct polarity.
c. Turn CURRENT controls fully clockwise.
d. Turn on supply and adjust VOLTAGE con-
trols until front panel meter indicates exactly max-
imum rated output voltage.
e. Differential voltmeter should indicate the
following:
6259B, 6260B
6261B
6268B, 6269B
5-11
Load Regulation.
Definition: The change ∆ EOUT in the
static value of dc output voltage re-
sulting from a change in load resist-
ance from open circuit to a value
which yields maximum rated output
current (or vice versa).
5-12 To check the constant voltage load regula-
tion, proceed as follows:
'a. Connect test setup shown in Figure 5-2.
b. Turn CURRENT controls fully clockwise.
c. Turn on supply and adjust VOLTAGE con-
trols until front panel meter indicates exactly max-
imum rated output current.
d. Read and record voltage indicated on dif-
ferential voltmeter.
e. Disconnect load resistor.
f. Reading on differential voltmeter should
not vary from reading recorded in Step (d) by more
than the following:
6259B, 6260B
6261B
6268B, 6269B
10 ±0.2Vdc
20 ±0.4Vdc
40 ±0.8Vdc
1.2mV
2.2mV
4.2mV
5-3
5-13 Line Regulation.
Definition: The change ∆ EOUT in the
static value of dc output voltage re-
sulting from a change in ac input volt-
age over the specified range from low
line (usually 207 volts) to high line
(usually 253 volts), or from high
line to low line.
5-14 To check the line regulation, proceed as
follows :
a. Connect test setup shown in Figure 5-2.
b. Connect variable auto transformer between
input power source and power supply power input.
c. Adjust variable auto transformer for 207
volts a c input.
d. Turn CURRENT controls fully clockwise.
e. Turn on supply and adjust VOLTAGE con-
trols until front panel meter indicates exactly maxi-
mum rated output voltage.
f. Read and record voltage indicated on dif-
ferential voltmeter.
g. Adjust variable auto transformer for 253V
ac input.
h. Reading on differential voltmeter should
not vary from reading recorded in Step (f) by more
than the following:
6259B,6260B
6261B
6268B, 6269B
5-15 Ripple and Noise.
Definition: The residual ac voltage
superimposed on the dc output of a
regulated power supply. Ripple and
noise may be specified and measured
in terms of its RIMS or (preferably)
peak-to-peak value.
Ripple and noise measurement can be made at any
input ac line voltage combined with any dc output
voltage and load current within the supply's rating.
5-16 The amount of ripple and noise that is pres-
ent in the power supply output is measured either
in terms of the RMS or (preferably) peak-to-peak
value. The peak-to-peak measurement is particu-
larly important for applications where noise spikes
could be detrimental to a sensitive load, such as
logic circuitry. The RMS measurement is not an
ideal representation of the noise, since fairly high
output noise spikes of short duration can be pres-
ent in the ripple without appreciably increasing the
RMS value,
5-17 Ripple Measurements. Figure 5-3A shows an
incorrect method of measuring p-p ripple. Note
that a continuous ground loop exists from the third
wire of the input power cord of the supply to the
third wire of the input power cord of the oscillo-
scope via the grounded power supply case, the
TM 11-6625-2958-14&P
1.2mV
2.2mV
4.2mV