Kikusui PAT160-25T, Руководство по эксплуатации

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4-6
PAT-T 4kW
4.4 Constant Voltage (CV) and Constant Current
(CC) Power Supplies
The PAT has a constant voltage power supply function that maintains the output
voltage at a constant level and a constant current power supply function that
maintains the output current at a constant level even when the load changes. The
condition in which the PAT is operating as a constant voltage power supply is called
the constant voltage (CV) mode. The condition in which the PAT is operating as a
constant current power supply is called the constant current (CC) mode. The
operation mode is determined by the following three values.
• Preset output voltage (Vs)
• Preset output current (Is)
• Load resistance (R
L
)
The operation modes are described below.
Fig.4-7 Constant voltage operation and constant c u rrent
operation
Fig.4-7 shows the operation modes of the PAT. We denote the load resistance as R
L
and the resistance calculated from the preset current and voltage as Rc (Rc = Vs/Is).
The power supply is designed so that it operates in CV mode in area
and CC
mode in area . The boundary is the line defined by R
L
= Rc. This line represents
the load at which the output voltage and the preset voltage are equal and the output
current and preset current are equal. If load resistance R
L
is greater than resistance
Rc, the operating point is in area , and the PAT operates in CV mode (point p). In
this case, preset current Is is the current limit.
When operating in CV mode, the output voltage is maintained at the preset voltage.
Output current I is determined by the relationship defined by the equation I = Vs/R
L
.
It is a current less than current limit Is. In this mode, the actual current that flows is
not necessarily equal to the specified value.
For loads in which transient peak current flows, preset current Is must be set so that
the peak value does not reach the current limit.
Conversely, if load resistance R
L
is less than resistance Rc, the operating point is in
area , and the PAT operates in CC mode (point q). In this case, preset voltage Vs
is the voltage limit.
0
I m a x I s
V s
V m a x
Output current Iout
Output
v
oltag
e
V
out
Crosso v er point
A = C V mode area
B
= CC mode area
V s = Preset v oltage
Is = Preset current
Rc =
V s/Is (Ohm’s Law)
R
L
= Load resistance
V max = Maximum preset v oltage
Imax = Maximum preset current
R
L
= R c R
L
> R c
R
L
< R c
p
q
A
B
A
B
A
B