2 Function
2.3 Overcurrent protection
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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 auto-
matically recovers when the fault condition is cleared.
The power supply which has a current foldback characteristics
may not start up when connected to nonlinear load such as lamp,
motor or constant current load. See the characteristics below.
lLDA10F LDA15F
2.4 Overvoltage protection
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Overvoltage protection circuit, clamping the output voltage by
zener diode, is built-in and comes into effect at over 115% of the
rated voltage (For 3V type, overvoltage protection kicks in at over
4V). The unit in an overvoltage protection mode cannot be recov-
ered by a user; it must be repaired at the factory. Overvoltage pro-
tection (diode) also comes into effect if the voltage is externally ap-
plied to the output side. Avoid applying voltage to the output side.
The overvoltage protection circuit is built-in and comes into effect
at 115 - 140% of the rated voltage (except 3V output voltage type :
it operates at 4.00 - 5.25V). The AC input should be shut down if
overvoltage protection is in operation. The minimum interval of
AC recycling for recovery is 2 to 3 minutes ( ).
The recovery time varies depending on input voltage.
Please avoid applying the over-rated voltage to the output termi-
nal. Power supply may operate incorrectly or fail.In case of oper-
ating a motor etc. , please install an external diode on the output
terminal to protect the unit.
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LDA10F LDA15F
LDA30F - LDA300W
Remarks:
LDA-21
Unit:[A typ]
No.
1
2
3
4
5
6
7
8
Model
Table 2.1 Inrush current
AC100V
15
15
15
15
15
30
30
30
AC200V
30
30
30
30
30
30
30
30
LDA
LDA
LDA
LDA
LDA
LDA
LDA
LDA
10F
15F
30F
50F
75F
100W
150W
300W
Fig.2.1 Current foldback characteristics
Note: In case of nonlinear load, the output is locked out at A point.
: Load characteristics of power supply.
: Characteristics of load (lamp, motor, constant current load, etc.)
2.1 Input voltage range
2.2 Inrush current limiting
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The range is from AC85V to AC264V or DC110V to DC370V.
AC input voltage must have a range from AC85V to AC264V for
normal operation. If the wrong input is applied, the unit will not op-
erate properly and/or may be damaged.
The range is from AC85V to AC132V/AC170V to AC264V which
is automatically selected internally. But after the input voltage is
applied, avoid changing AC100V AC200V.
AC input voltage must have a range from AC85V to AC132V/
AC170V to AC264V for normal operation. If the wrong input is ap-
plied, the unit will not operate properly and or may be damaged.
Inrush current limiting is built-in.
If a switch on the input side is installed, it has to be the one han-
dling the input inrush current.
The thermistor is used for protection from inrush current. When
power is turned ON/OFF repeatedly within a short period of time,
it is necessary to have enough time for power supply to cool
down.
The thyristor technique is used for protection from inrush current.
When power is turned ON/OFF repeatedly within a short period of
time, it is necessary to have enough time between power ON and
OFF to operate resistance circuit for inrush current.
In cases that conform with safety standard, input voltage range is
AC100-AC240V(50/60Hz).
In cases that conform with safety standard, input voltage range is
AC100-AC120V, AC200-AC240V(50/60Hz).
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LDA10F - LDA75F
LDA100W - LDA300W
LDA10F - LDA150W
LDA300W
LDA
Instruction Manual
AC-DC Power Supplies Open Frame/Enclosed type
