HP (Hewlett-Packard) 6205B ユーザーズマニュアル
SECTION V
MAINTENANCE
TM 11-6625-2965-14&P
5-1 INTRODUCTION
5-2 Upon receipt of the power supply, the per-
This check is suitable for incoming inspection. If
a fault is detected in the power supply while mak-
ing the performance check or during normal opera-
tion, proceed to the troubleshooting procedures
a fault is detected in the power supply while mak-
ing the performance check or during normal opera-
tion, proceed to the troubleshooting procedures
ments and calibrations (Paragraph 5-60). Before
returning the power supply to normal operation,
repeat the performance check to ensure that the
fault has been properly corrected and that no other
faults exist. Before doing any maintenance checks,
turn-on power supply, allow a ha if-hour warm-up,
and read the general information regarding meas-
returning the power supply to normal operation,
repeat the performance check to ensure that the
fault has been properly corrected and that no other
faults exist. Before doing any maintenance checks,
turn-on power supply, allow a ha if-hour warm-up,
and read the general information regarding meas-
urement techniques (Paragraph 5-3).
5-3
5-4
GENERAL MEASUREMENT TECHNIQUES
The measuring device must be connected
across the sensing leads of the supply or as close
to the output terminals as possible when measur-
ing the output impedance, transient response, reg-
ulation, or ripple of the power supply in order to
achieve valid measurements. A measurement made
acress the load includes the impedance of the
to the output terminals as possible when measur-
ing the output impedance, transient response, reg-
ulation, or ripple of the power supply in order to
achieve valid measurements. A measurement made
acress the load includes the impedance of the
leads to the load and such lead lengths can easily
have an impedance several orders of magnitude
greater than the supply impedance, thus invalidat-
ing the measurement.
greater than the supply impedance, thus invalidat-
ing the measurement.
5-5 The monitoring device should be connected
tics should never be measured on the front termi-
nals if the load is connected across the rear termi-
nals if the load is connected across the rear termi-
nals. Note that when measurements are made at
the front terminals, the monitoring leads are con-
nected at A, not B, as shown in Figure 5-1. Fail-
ure to connect the measuring device at A will re-
the front terminals, the monitoring leads are con-
nected at A, not B, as shown in Figure 5-1. Fail-
ure to connect the measuring device at A will re-
sult in a measurement that includes the resistance
of the leads between the output terminals and the
point of connection.
point of connection.
Figure 5-1.
Front Pane1 Terminal Connections
Figure 5-2. Output Current Measurement Technique
5-6 For output current measurements, the current
sampling resistor should be a four-terminal resis-
tor. The four terminals are connected as shown in
Figure 5-2. In addition, the resistor should be of
sampling resistor should be a four-terminal resis-
tor. The four terminals are connected as shown in
Figure 5-2. In addition, the resistor should be of
the low noise, low temperature coefficient (less
than 30ppm/°C) type and should be used at no
than 30ppm/°C) type and should be used at no
more than 5% of its rated power so that its temper-
ature rise will be minimized.
ature rise will be minimized.
5-7
When using an oscilloscope, ground one ter-
minal of the power supply and then ground the case
of the oscilloscope to this same point. Make cer-
tain that the case is not also grounded by some
other means (power line). Connect both oscillo-
of the oscilloscope to this same point. Make cer-
tain that the case is not also grounded by some
other means (power line). Connect both oscillo-
scope input leads to the power supply ground ter-
minal and check that the oscilloscope is not ex-
minal and check that the oscilloscope is not ex-
hibiting a ripple or transient due to ground loops,
pick-up, or other means.
pick-up, or other means.
5-1