use resistors and potentiometers of the following specifications:
Potentiometers .....Cermet type, coefficient less than ±300ppm/
C
+VOUT
-VOUT
-S
+S
VTRM
External VR1
10kΩ
TUNS1200F
Fig.3.7 Connecting External Devices (TUNS1200F)
(2) Output voltage adjustment by external voltage
¡
By applying a voltage externally to VTRM, output voltage be-
comes adjustable.
Output level is able to be calculated by following equation when
the VTRM terminal voltage. However, it cannot be set beyond the
upper limit of the output voltage variable range.
Output voltage [V] =
The voltage between
VTRM and -S[V] ×Rated output voltage [V] ...
1
2.5 [V]
¡
Do not set the external applied voltage of the terminal to -0.3V or
less, and 5.0V or more.
¡
When the VTRM terminal voltage is 4.5V or higher, the rated volt-
age is output.
¡
Do not set the VTRM terminal voltage within the range of 4.0 to
4.5V, because the output voltage to be indefinite.
Output voltage
VTRM [V]
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
110%
120%
130%
0
0.5
1
1.5
2
2.5
3
3.5
4
5
4.5
Fig.3.8 VTRM-Output Voltage (TUNS1200F12, TUNS1200F28)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
110%
120%
130%
0
0.5
1
1.5
2
2.5
2.75
3
3.5
4
5
4.5
Output voltage
VTRM [V]
Fig.3.9 VTRM-Output Voltage (TUNS1200F48)
0.01
μ
F
4.7kΩ
10kΩ
VTRM
-S
5V
Fig.3.10 VTRM circuit
¿
-Y1 (TUNS300F/500F/700F/1200F)
¡
Adjustable voltage range of 48V output is changed to ± 20%.
*
Adjustable voltage range of standard type except 48V output is
±20%.
¡
Safety standard, is considered as Non SELV output.
3.10 Adjustable constant current range
¿
TUNS1200F (ITRM)
¡
Output current for the constant current can be adjusted by con-
necting external resistors to ITRM or by applied voltage externally.
¡
When the output current is adjusted to around 0A, the unit might
be unstable.
¡
When the output current adjustment is not used, open the ITRM
pin.
(1) Constant current adjustment by potentiometer
¡
By connecting the external potentiometer (VR2) as shown in
Fig.3.11, output current for constant current becomes adjustable.
¡
The wiring to the potentiometer should be as short as possible.
As the ambient temperature fluctuation characteristics deteriorate
depending on the types of resistors and potentiometers, please
use resistors and potentiometers of the following specifications:
Potentiometers .....Cermet type, coefficient less than ±300ppm/
C
+VOUT
-VOUT
-S
+S
ITRM
External VR2
10kΩ
TUNS1200F
Fig.3.11 Connecting External Devices (TUNS1200F)
AC-DC Power Supplies Bus Converter.Power Module Type TUNS300F, TUNS500F, TUNS700F, TUNS1200F
Instruction Manual
TUNS-27
July 27, 2020
