¡The output voltage may become unstable at low temperature due
to the ESR of power thermistor. In this case, increase the capaci-
tance of Cbc more than recommended value or connect same
capacitors in parallel. Please evaluate before use.
2.2 Wiring output pin
(1) Co : Output capacitor
¡Install an external capacitor Co between +VOUT and -VOUT pins
for stable operation of the power supply (Fig.1.1).
Recommended capacitance of Co is shown in Table 2.3.
¡Select the high frequency type capacitor. Output ripple and start-
up waveform may be inuenced by ESR-ESL of the capacitor and
the wiring impedance.
¡Install a capacitor Co near the output pins (within 50mm from the
pins).
¡When the power supply is used under 0Cambient temperature,
output ripple voltage increases. In this case, connect 3 capacitors
Co in parallel connection.
Table 2.3 Recommended capacitance Co[μF]
Model Temperature of base plate
Tc=0 to +100CTc=-40 to +100C
Output voltage
(V) TUNS50F TUNS100F TUNS50F TUNS100F
5 2200 2200 2200×3 2200×3
12 470 470 470×3 470×3
24 220 220 220×3 220×3
The specied ripple and ripple noise are measured by the method
introduced in Fig.2.1.
C4 :
5V,12V 10mF
24V 4 .7mF
FG
+
F1 TH1
FG FG
CY
C1
+BC -BC
Cbc
AC IN
AC1
AC2
+VOUT
-VOUT
-S
+S
TUNS50F
TUNS100F
C2
Load
C4
R
C
+
Co
50mm
Oscilloscope
BW:100MHz
1.5m
50W
Coaxial
Cable R=50W
C=0.01mF
Noise
filter
+S, -S : TUNS100F
Fig.2.1 Method of Measuring Output Ripple and Ripple Noise
2.3 Wiring +BC/-BC pins
(1) Cbc : Smoothing capacitor for boost voltage
¡In order to smooth boost voltage, connect Cbc between +BC and
-BC. Recommended capacitance of Cbc is shown in Table2.4.
¡Note that +BC and -BC terminals have high voltage (DC385V typ).
¡Keep the capacitance within the allowable external capacitance.
¡Select a capacitor of which the boost voltage ripple voltage does
not exceed 30Vp-p.
¡When the power supply is operated under -20C, it may make
the boost voltage unstable due to the characteristic of equivalent
series resistor. Please choose the capacitor which has more than
recommended capacitance.
Table 2.4 Recommended capacitance Cbc
No. Model Voltage Cbc Allowable
capacitance range
1 TUNS50F DC420V
or more
82μF 47 to 150μF
2 TUNS100F 120μF 68 to 220μF
(2) C2 : Capacitor for boost voltage
¡Install external capacitors C2 with capacitance shown in table 2.5.
¡If capacitors C2 are not installed, it may cause the failure of the
power supply or external components.
Table 2.5 Recommended capacitance C2
No. Model Voltage Capacitance Rated ripple
current
1 TUNS50F DC450V 0.47μF or more 1A or more
2 TUNS100F 0.47μF or more 1A or more
3 Function
3.1 Input voltage range
¡The input voltage range is from 85 VAC to 264 VAC.
¡In cases that conform with safety standard, input voltage range is
AC100-AC240V(50/60Hz).
¡Be aware that use of voltages other than those listed above may
result in the unit not operating according to specications, or may
cause damage. Avoid square waveform input voltage, commonly
used in UPS and inverters.
3.2 Overcurrent protection
¡Overcurrent protection is built-in and comes into effect over 105%
of the rated current.
Overcurrent protection prevents the unit from short circuit and
overcurrent condition. The unit automatically recovers when the
fault condition is cleared.
¡When the output voltage drops at overcurrent, the average output
current is reduced by hiccup operation of power supply.
3.3 Overvoltage protection
¡Overvoltage protection circuit is built-in. If the overvoltage protec-
tion circuit is activated, shut down the input voltage, wait more
than 3 minutes and turn on the AC input again to recover the out-
put voltage. Recovery time varies depending on such factors as
input voltage value at the time of the operation.
Remarks:
Please note that devices inside the power supply might fail when
voltage of more than rated output voltage is applied to output ter-
minal of the power supply. This could happen when the customer
tests the overvoltage performance of the unit.
To check the function of overvoltage protection, adjust the output
voltage by changing TRM voltage. Please contact us for details.
TUNS50F, TUNS100F
AC-DC Power Supplies Bus Converter.Power Module Type
Instruction Manual
TUNS-20
July 27, 2020
