Kikusui PLZ1004W - Operation of the CR Mode

A-4 Appendix PLZ-4W
A.2.2 Operation of the CR Mode
In CR mode, the PLZ-4W sinks current proportional to the voltage variation.
■ CR mode operation
When the PLZ-4W is used in CR mode, the PLZ-4W operates as a resistive load as
shown in Fig. A-4. When the voltage (V1) of the constant-voltage power supply var-
ies, the PLZ-4W sinks current to maintain I = V/R, with the specified resistance R
fixed. This mode cannot be used with an AC circuit.
Fig. A-4 Equivalent circuit of the constant resistance load and opera-
tion
■ Transition of the operating point: Overpower protection (OPP)
We will consider the case when checking the load characteristics of the constant-
voltage power supply of Fig. A-4 using CR mode.
Fig. A-5 Transition of the operating point in CR mode (OPP trip point)
If the overcurrent protection (OCP) setting I
OCP
is greater than the current value I
B
at point B, when the PLZ-4W resistance is decreased (R
1
R
2
R
B
) and the input
current (load current) is increased with the voltage of the constant-voltage power
supply at V1, the operating point moves along segment AB (A
1
A
2
B). When
point B is reached, overpower protection (OPP) trips.
At this point, two types of operation are available on the PLZ-4W depending on the
protection action setting of the OPP.
If Protect Action is set to LOAD OFF, the load is turned off.
0
V2
V1
I1
I2
V2
V1
I1
I2
==
R
I
V
PLZ-4W Series Electronic Load
Constant voltage
power supply
Resistance (V/I) is constant
even when the voltage and
current vary
Current I
Voltage V
V1
Input current [A]
Input voltage [V]
Log scale
V1
A
B
Constant power line
(OPP setting)
Operating area
OPP trip point
Constant resistance line
(Constant resistance settings: R
1 , R 2 , and R B )
I B
I OCP
A 1
A 2
R 1
R 2
R B