Keysight E3630A, Руководство по эксплуатации и обслуживанию

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Service Information 5
Keysight E3630A Operating and Service Manual 49
problems, one end of this sampling resistor should be connected to the same
output terminal of the supply which will be shorted to ground. An accurate
voltmeter is then placed across the sampling resistor and the output current
calculated by dividing the voltage across the sampling resistor by its ohmic value.
The total resistance of the series combination should be equal to the full load
resistance as determined in the preceding paragraphs. Of course, if the value of
the sampling resistor is very low when compared to the full load resistance, the
value of the sampling resistor may be ignored. The meter shunt recommended in
Table 5-1 , for example, has a resistance of only 100 m Ω and can be neglected
when calculating the load resistance of the supply. Figure 5-3 shows a four
terminal meter shunt. The load current through a shunt must be fed from the
extremes of the wire leading to the resistor while the sampling connections are
made as close as possible to the resistance portion itself.
Figure 5-3 Current sampling resistor connections
Rated output, tracking, meter accuracy, and current limit
To check that all supplies will furnish their maximum rated output voltage and
current, that the ±20 V outputs track each other, that the front panel meters are
accurate, and that the current limit circuits function, proceed as follows: