Agilent Technologies E3646A, User Manual, Page: 154 / 211

Chapter 7 Tutorial
Output Characteristics
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Figure 7-5 shows the operating modes of the output of this 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.