Agilent Technologies E3631-90002, User Manual, Page: 143 / 166

Chapter 7 Tutorial
Output Characteristics
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Figure 7-5 shows the operating modes of the three outputs of the Agilent
E3631A power supply. The operating point of one supply will be either above or
below the line R
L
= R
C
. This line represents a load where the output voltage
and the output current are equal to the voltage and current setting. When the
load R
L
is greater than R
C
, the output voltage will dominate since the current
will be less then the current setting. The power supply is said to be in
constant-voltage mode. The load at point 1 has a relatively high resistance
value (compared to R
C
), the output voltage is at the voltage setting, and the
output current is less than the current setting. In this case the power supply
is in the constant-voltage mode and the current setting acts as a current limit.
Figure 7-5. Output Characteristics
When the load R
L
is less than R
C
, the output current will dominate since the
voltage will be less than the set voltage. The power supply is said to be in
constant-current mode. The load at point 2 has a relatively low resistance,
the output voltage is less than the voltage setting, the output current is at the
current setting. The supply is in constant-current mode and the voltage
setting acts as a voltage limit.