HP 6960A - Detailed Test Procedure

Model 6960 A Section V
A '-------1
LOAD LEAD~
OUTPUT TERMINAL
DO NOT
MONITOR HERE
MONITOR HERE ~
Fig. 5-3 Recommended Connection at the Power Supply
f) AC Internal Impedance.
Make your connections according to the block diagram in Figure 5-2. This
measurement
is made by driving a constant 10 mA alternating current through the
power supply and measuring the voltage drop across the output terminols. The
internal
impedance can be easily calculated by Ohm's law.
By checking the internal impedance you should consider that the power supply's
ripple and noise add to the voltmeter reoding. For performing very exact
measurements you have to fi Iter out all ripple and noise voltages up to a fre-
quency of about 500 cycles or to use a sensitive wave analyser.
Also take care to prevent stray ground loops which make impossible reliable
measurement of internal impedance.
Up to 1 Kc the internal resistance of the Model 6960 A should be below 0.02 Q
1 Kc up to 50 Kc below 0.5 {1 •
5-9 Detailed Test Procedure
5-10 The following test procedure should be performed only after the performance test
has shawn that this instrument is faulty. Do not perform this procedure as an inco-
ming inspection or proof of performance check. The following test procedure contains
extra checks to help you analyze the troubles in this instrument. These extra checks
and the data they contain cannot be considered as specifications.
Because of internal adjustment or even possible replacement of components, top,
bottom, and the side covers may have to be removed. Make sure that the ac fuse
is inserted in the fuse holder. The VOLTAGE ADjUST an the front panel should be
in a mid-range position, the CURRENT LIMIT control turned fully clockwise. Use
5-5