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 of less than 1 min-
ute. The unit automatically recovers when the fault condition is
cleared.
When the overcurrent/short circuit condition continues more than
1 minute, it may damage devices inside the power supply.
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.
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LCA10S LCA15S LCA30S
Remarks:
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LCA30S LCA50S LCA75S
LCA100S LCA150S
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.
2.5 Output voltage adjustment range
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Adjustment of output voltage is possible by using potentiometer
(Only available to 3V output voltage type).
Output voltage is increased by turning potentiometer clockwise
and is decreased by turning potentiometer counterclockwise.
Modified unit ”-Y” is recommended which can adjust the output
voltage.
Adjustment of output voltage is possible by using potentiometer
(Only available to 3 and 5V output voltage type).
Output voltage is increased by turning potentiometer clockwise
and is decreased by turning potentiometer counterclockwise.
Modified unit ”-Y” is recommended which can adjust the output
voltage.
LCA-19
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.)
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LCA50S LCA75S LCA100S LCA150S
LCA10S LCA15S LCA30S
LCA50S LCA75S LCA100S LCA150S
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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 of less than 15
seconds. The unit automatically recovers when the fault condition
is cleared.
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. The AC input should be shut
down if overvoltage protection is in operation. The minimum inter-
val of AC recycling for recovery is 1.5 minutes.
The recovery time varies depending on input voltage.
2.4 Overvoltage protection
A
V
100
Output
V
olt
age
[ V
]
Load factor [%]
3 Series Operation and
Parallel Operation
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LCA10S LCA15S LCA30S
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Series operation is available by connecting the output 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.
(a) When the output voltage is less than 5V.
D1 - D4: Please use Schottky Barrier Diode
LCA
Power
Supply
+
Power
Supply
+
Load
D1
D2
D4
D3
-
-
Instruction Manual
AC-DC Power Supplies Open Frame/Enclosed type
June 29, 2011
