¡
As wiring or load impedance may generate oscillation or large
fluctuations in output voltage, make sure enough evaluation is
given advance.
3.6 Adjustable voltage range
¡
Output voltage bVOUT and -VOUT can be adjusted by
connecting external resistors to TRM.
¡
When the output voltage adjustment is not used, open the TRM
pin respectively.
¡
When the output voltage adjustment is used, note that the over-
voltage protection circuit operates when output voltage is set too
high.
¡
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:
Resistors ............. Metal film type, coefficient less than ±100ppm/
C
Potentiometers ... Cermet type, coefficient less than ±300ppm/
C
¡
Output voltage can be adjusted by connecting an external potenti-
ometer (VR1) and resistors (R1 and R2) as shown in Fig. 3.3.
Output voltage will increase if the resistance between
2
and
3
is
reduced by turning the potentiometer.
Recommended values for external components are shown in
Table 3.1.
Consult us if the power module is used in a different configuration.
+VOUT
-VOUT
-S
+S
TRM
External Resistor R1
External VR1
External Resistor R2
1
2
5k
W
3
TUNS50F
TUNS100F
+S, -S : TUNS100F
Fig. 3.3 Connecting External Devices (TUNS50F/TUNS100F)
Table 3.1 Recommended Values of External Resistors (TUNS50F, TUNS100F)
No.
Output
Voltage
Adjustable Range
VOUT±5%
VOUT±10%
R1
R2
R1
R2
1
5V
10k
W
2.7k
W
4.7k
W
1k
W
2
12V
12k
W
2.2k
W
5.6k
W
560
W
3
24V
27k
W
1.8k
W
15k
W
470
W
3.7 Withstanding Voltage / Isolation Voltage
¡
When testing the withstanding voltage, make sure the voltage
is increased gradually. When turning off, reduce the voltage
gradually by using the dial of the hi-pot tester. Do not use a
voltage tester with a timer as it may generate voltage several
times as large as the applied voltage.
3.4 Thermal protection
¡
When the power supply temperature is kept above 100
C
, the
thermal protection will be activated and simultaneously shut down
the output.
When the thermal protection is activated, shut off the input voltage
and eliminate all the overheating conditions. To recover the output
voltage, keep enough time to cool down the power supply before
turning on the input voltage again.
3.5 Remote sensing
¿
TUNS50F
¡
Remote sensing is not built-in.
¿
TUNS100F
¡
Remote sensing is built-in.
(1) When the remote sensing function is not in use
+S
+VOUT
-S
-VOUT
+
Co
Short at pin root
Load
TUNS100F
Fig. 3.1 Connection when the remote sensing is not in use
¡
When the remote sensing function is not in use, it is necessary to
confirm that pins are shorted bS & +VOUT and between
-S & -VOUT.
¡
Wire bS & +VOUT and between -S & -VOUT as short as
possible.
Loop wiring should be avoided.
This power supply might become unstable by the noise coming
from poor wiring.
(2) When the remote sensing function is in use
+S
Co
-S
+VOUT
-VOUT
+
Wire as close as possible
Load
TUNS100F
Fig. 3.2 Connection when the remote sensing is in use
¡
Twisted-pair wire or shield wire should be used for sensing wire.
¡
Thick wire should be used for wiring between the power supply
and a load.
Line drop should be less than 0.5V.
Voltage bVOUT and -VOUT should remain within the
output voltage adjustment range.
¡
If the sensing patterns are short, heavy-current is drawn and the
pattern may be damaged.
The pattern disconnection can be prevented by installing the pro-
tection parts as close as a load.
AC-DC Power Supplies Bus Converter.Power Module Type TUNS50F, TUNS100F
Instruction Manual
TUNS-21
July 27, 2020
