Kikusui PLZ-3WH Series, Operation Manual

Page: 90 / 172

4-50
Chapter 4: Operating Procedure
(b) External resistance method
An external resistance from 0 Ω to approx. 10 k Ω is connected to the load unit to flow the input current in reverse
proportion to the resistance.
Fig. 4.6-3
● ● ● ● ●
Setup procedure
(1) Check that the [LOAD] switch is turned off, and set the ISET value to the rated current on the front panel.
(2) Press the [POWER] switch to turn off the load unit.
(3) Connect the external variable resistor to J2 terminals 11 and 12 on the rear panel, and maximize the resistance.
(4) On the rear panel, set the setup switch [SW2] to the “LOCAL” position and [SW3] to the “R” position.
(5) Press the [POWER] switch to turn on the load unit.
(6) Press the [I SET] key on the front panel to enable the CC mode.
(7) Using the [SHIFT] + [STOP] (KEYLOCK) keys, put the load unit into keylock condition.
The external variable resistor used should be resistant to temperature and aging, and its residual resistance should not
exceed 300 Ω . We recommend use of a wire wound resistor, metal film resistor, or multirotational potentiometer. To
prevent noise interference, use twisted pair or shielded signal cable.
If the ISET value is set to any value other than the rated current, the set current range fails to cover the standard value.
Note that if the ISET value is set to 0 A, control with external resistance becomes impossible and the rated current is
supplied to the load terminal.
When the external resistance is used for external control, even the CC mode needs the same terminals as the CR mode.
Therefore, always recheck the operating mode.
When Rin is equal to 10 k Ω , Io is securely 0 A. This may cause a minor offset as shown in the figure below.
Im
Input
Current
0A
Rin
0Ω 5kΩ 10kΩ
Rin : External variable resistor
Im :
: Logical input current
: Actual input current
Rated current
11
12
Equivalent circuit
J2
Rin
Io
≒
Im 1
−
Rin( Ω )
10000
Io ： Input current
Im
：
Rated current
Rin ： External variable resistor
0 ≦ Rin ≦ approx. 10 (k Ω )
≒
Im 1
−
Rin(k Ω )
10
1mA
MAX12V
Fig. 4.6-4