4.2 Overcurrent protection
¡
Overcurrent protection is built-in and comes into effect at 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 intermittent operation of power supply.
4.3 Overvoltage protection
¡
The overvoltage protection circuit is built-in and comes into effect
at 110% to 160% of the rated output voltage. When the load fac-
tor is less than 30%, output voltage may be increased more than
maximum voltage depending on the failure mode.
¡
Please note that devices inside the power supply might fail when
voltage more than rated output voltage is applied to output pin of
the power supply. This could happen when the customer tests the
overvoltage performance of the unit.
4.4 Isolation
¡
For a receiving inspection, such as Hi-Pot test, increase (de-
crease) the voltage gradually for a start (shut down). Avoid using
Hi-Pot tester with timer because it may generate voltage a few
times higher than the applied voltage, at ON/OFF of a timer.
4.5 Reducing standby power
¡
A circuit reducing standby power is built in TUHS.
(standby power of AC100V input : 0.5W max)
The load factor: Io=0-30%, the internal switch element is intermit-
tent operated, and the switching loss is decreased. The speci-
fication of the Ripple/Ripple Noise changes by this intermittent
operation. The value of the ripple/ripple Noise when intermittent
operates changes in the input voltage and the output current.
Please contact us for details.
5 Series and Parallel
Operation
5.1 Series operation
¡
Series operation is available by connecting the outputs of two or
more power supplies as shown below. Output current in series
connection should be lower than the lowest rated current in each
unit.
Load
Load
Power
Supply
Power
Supply
Load
Power
Supply
Power
Supply
(a)
(b)
Fig.5.1 Examples of series operation
5.2 Parallel operation
¡
Parallel operation is not possible.
¡
Redundancy operation is available by wiring as shown below.
Power
Supply
Power
Supply
Load
I
I
1
I
3
2
Fig.5.2 Example of Redundancy Operation
¡
Even a slight difference in output voltage can affect the balance
between the values of I
1
and I
2
.
Please make sure that the value of I
3
does not exceed the rated
current of a power supply.
I
3
the rated current value
AC-DC Power Supplies PCB Mount Type
Instruction Manual
TUHS-17
