Basic Characteristics Data
Basic Characteristics Data
Inrush
current
protection
PCB/Pattern
Material
Single
sided
Double
sided
LFA
Model Circuit method
Switching
frequency
[kHz]
*1
Input
current
[A]
LFA10F Flyback converter 100 0.26 LF CEM-3 Yes Yes No
LFA15F Flyback converter 100 0.35 Thermistor CEM-3 Yes Yes No
LFA30F Flyback converter 130 0.65 Thermistor CEM-3 Yes Yes No
Series/Parallel
operation availability
Series
operation
Parallel
operation
*2
LFA50F
LFA75F
LFA100F
LFA150F
LFA240F
LFA300F
*1 The value of input current is at ACIN 100V and rated load.
*2 Refer to Instruction Manual 2.
Active fi lter 60-440
Flyback converter 130
Active fi lter 60-440
Flyback converter 130
Active fi lter 60
Forward converter 140
Active fi lter 60
Forward converter 140
Active fi lter 60
Forward converter 140
Active fi lter 60
Forward converter 140
0.67 Thermistor CEM-3 Yes Yes No
1.0 Thermistor CEM-3 Yes Yes No
1.3 Thermistor CEM-3 Yes Yes No
2.0 Thermistor CEM-3 Yes Yes No
3.3 SCR CEM-3 Yes Yes No
4.1 SCR CEM-3 Yes Yes No
LFA-20
AC-DC Power Supplies Open Frame/ Enclosed Type
Instruction Manual
1 Function
1.1 Input voltage range
1.2 Inrush current limiting
1.3 Overcurrent protection
1.4 Overvoltage protection
1.5 Output voltage adjustment range
1.6 Output ripple and ripple noise
1.7 Isolation
1.8 Reducing standby power
2 Series Operation and Parallel Operation
2.1 Series Operation
2.2 Parallel Operation
3 Assembling and Installation Method
3.1 Installation method
3.2 Derating
3.3 Mounting screw
3.4 Expectancy life and warranty
LFA-22
LFA
LFA-22
LFA-22
LFA-22
LFA-22
LFA-22
LFA-23
LFA-23
LFA-23
LFA-23
LFA-23
LFA-24
LFA-24
LFA-24
LFA-24
LFA-28
LFA-28
4 Ground
5 Option and Others
5.1 Outline of options
5.2 Others
LFA-30
LFA-30
LFA-30
LFA-32
LFA-21
AC-DC Power Supplies Open Frame/ Enclosed Type
1 Function
LFA
1.1 Input voltage range
The range is from AC85V to AC264V or DC120V to DC370V
¡
(please see SPECIFICATIONS for details).
In cases that conform with safety standard, input voltage range is
¡
AC100-AC240V (50/60Hz).
If input value doesn’t fall within above range, a unit may not oper-
¡
ate in accordance with specifi cations and/or start hunting or fail.
If you need to apply a square waveform input voltage, which is
commonly used in UPS and inverters, please contact us.
When the input voltage changes suddenly, the output voltage ac-
¡
curacy might exceed the specifi cation. Please contact us.
LFA10F, LFA15F, LFA30F
¿
A power factor improvement circuit (active fi lter) is not built-in. If
¡
you use multiple units for a single system, standards for input harmonic current may not be satisfi ed. Please contact us for details.
LFA10F, LFA15F, LFA30F, LFA50F, LFA75F,
¿
LFA100F, LFA150F, LFA240F, LFA300F
Operation stop voltage is set at a lower value than that of a stan-
¡
dard version (derating is needed).
-Use Conditions
LFA10F 5W (3W)
LFA15F 7.5W (5W)
LFA30F 10W (7.5W)
LFA50F 15W (10W)
LFA75F 25W (15W)
LFA100F 30W (20W)
LFA150F 50W (30W)
LFA240F 80W
LFA300F 100W (75W)
Input AC50V or DC70V
Duty 1s/30s
Please avoid using continuously for more than 1 second
*
under above conditions. Doing so may cause a failure.
Output ( ) 3.3V
Instruction Manual
LFA240F, LFA300F
¿
Thyristor technique is used in the inrush current limiting circuit.
¡
When you turn power ON/OFF repeatedly within a short period of
time, please have enough intervals so that the inrush current limiting circuit becomes operative.
When the switch of the input is turned on, the primary inrush cur-
¡
rent and secondary inrush current will be generated because the
thyristor technique is used for the inrush current limiting circuit.
1.3 Overcurrent protection
An overcurrent protection circuit is built-in and activated at 105%
¡
of the rated current or 101% of the peak current. A unit automatically recovers when a fault condition is removed.
Please do not use a unit in short circuit and/or under an overcurrent condition.
Intermittent Operation Mode
¡
Intermittent operation for overcurrent protection is included in a
part of series. When the overcurrent protection circuit is activated
and the output voltage drops to a certain extent, the output becomes intermittent so that the average current will also decrease.
1.4 Overvoltage protection
An overvoltage protection circuit is built-in. If the overvoltage pro-
¡
tection circuit is activated, shut down the input voltage, wait more
than 3 minutes and turn on the AC input again to recover the output voltage. Recovery time varies depending on such factors as
input voltage value at the time of the operation.
In option -R2, overvoltage protection is removed by toggling ON/
¡
OFF signal of remote control.
Remarks :
Please avoid applying a voltage exceeding the rated voltage to an
output terminal. Doing so may cause a power supply to malfunction or fail. If you cannot avoid doing so, for example, if you need
to operate a motor, etc., please install an external diode on the
output terminal to protect the unit.
1.5 Output voltage adjustment range
1.2 Inrush current limiting
An inrush current limiting circuit is built-in.
¡
If you need to use a switch on the input side, please select one
¡
that can withstand an input inrush current.
LFA10F
¿
Resistance for line fi lter is used for inrush current limiting.
¡
LFA15F, LFA30F, LFA50F, LFA75F, LFA100F,
¿
LFA150F
Thermistor is used in the inrush current limiting circuit. When you
¡
turn the power ON/OFF repeatedly within a short period of time,
please have enough intervals so that a power supply cools down
before being turned on.
LFA-22
Adjustment of output voltage is possible by using potentiometer.
¡
Please refer to instruction manual 5.1.
Option ”-Y” is recommended which can adjust the output voltage.
¡
AC-DC Power Supplies Open Frame/ Enclosed Type
Instruction Manual
1.6 Output ripple and ripple noise
Output ripple noise may be infl uenced by measurement environ-
¡
ment, measuring method fi g.1.1 is recommended.
+Vout
2
C
1
C
+
-Vout
Osiloscope/
Ripple noise meter
Bw:20MHz
1 :
Film capacitor 0.1μF
C
2 :
Aluminum electrolytic capacitor 22μF
C
Fig.1.1 Measuring method of Ripple and Ripple Noise
Remarks :
When GND cable of probe with fl ux of magnetic force from power
supply are crossing, ripple and ripple noise might not measure
correctly.
Please note the measuring environment.
150mm
Differential probe
Load
LFA100F, LFA150F, LFA240F, LFA300F
¿
As for option -R2, reducing standby power is possible by OFF sig-
¡
nal of the remote control.
Please refer to instruction manual 5.1.
2 Series Operation and
Parallel Operation
2.1 Series Operation
LFA10F, LFA15F, LFA30F, LFA50F, LFA75F
¿
Series operation is available by connecting the outputs of two or
¡
more power supplies with the same output voltage, as shown below. Output current in series connection should be lower than the
lowest rated current in each unit.
12V or less 15V or more
Power
+
Supply
-
Power
+
-
Supply
D1-D4 : Use a schottky barrier
diode with low forward
voltage.
Fig.2.1 Examples of connecting in series operation (a)
D1
D3
D2
D4
Power
+
Supply
Load
Power
Supply
D1,D2 : Use a schottky barrier
D1
-
+
D2
-
diode with low forward
voltage.
LFA
Load
Bad example Good example
Fig.1.2. Example of measuring output ripple and ripple noise
1.7 Isolation
For a receiving inspection, such as Hi-Pot test, gradually increase
¡
(decrease) the voltage for the start (shut down). Avoid using HiPot tester with the timer because it may generate voltage a few
times higher than the applied voltage, at ON/OFF of a timer.
1.8 Reducing standby power
LFA10F, LFA15F
¿
A circuit reducing standby power is built in LFA10F and LFA15F.
¡
(standby power : 0.5W typ)
The load factor: Io=0-35%, the internal switch element is intermit-
tent operated, and the switching loss is decreased.
The specification 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.
+
Power
Supply
-
Power
+
Supply
-
Fig.2.2 Examples of connecting in series operation (b)
LFA100F, LFA150F, LFA240F, LFA300F
¿
You can use a power supply in series operation. The output cur-
¡
rent in series operation should be lower than the rated current of a
power supply with the lowest rated surrent among power supplies
that are serially connected. Please make sure that no surrent exceeding the rated current fl ows into a power supply.
Power
+
Supply
Power
Supply
Only LFA300F -3R3 and -5.
*
Use a schottky barrier diode
with low forward voltage.
*
-
+
*
-
(a) (b)
Fig.2.3 Examples of connecting in series operation
Load
Power
Supply
Power
Supply
Load Load
+
-
LoadLoad
+
-
LFA-23
AC-DC Power Supplies Open Frame/ Enclosed Type
2.2 Parallel Operation
Parallel operation is not possible.
¡
Redundancy operation is available by wiring as shown below.
¡
LFA
I1 I3
Power
Supply
+
-
Instruction Manual
There is a possibility that it is not possible to cool enough when
¡
the power supply is used by the sealing up space as showing in
Figure 3.2.
Please use it after confi rming the temperature of point A and point
B of Instruction Manual 3.2.
Case
I
2
Power
Supply
Fig.2.4 Example of redundancy operation
Even a slight difference in output voltage can affect the balance
¡
between the values of I
Please make sure that the value of I
current of a power supply.
+
-
and I2.
1
does not exceed the rated
3
[ the rated current value
I
3
Load
3 Assembling and
Installation Method
3.1 Installation method
This power supply is manufactured by SMD technology.
¡
The stress to P.C.B like twisting or bending causes the defect of
the unit,so handle the unit with care.
In case of metal chassis, keep the distance between d
¡
insulate between lead of component and metal chassis, use the
spacer of 8mm or more between d
the insulation sheet between power supply and metal chassis.
. If it is less than d1 & d2, insert
1
& d2 for to
1
Power supply
Fig.3.2 Installation example
3.2 Derating
Environment to use it and Installation environment
¡
When using it,it is necessary to radiate heat by the heat of the pow-
er supply.
Table 3.1 - 3.9 shows the relation between the upper limit tempera-
ture (Point A and Point B) and load factors.
Please consider the ventilation so that the convection which is
enough for the whole power supply is provided.
And temperature of Point A and Point B please become lower than
upper limit temperature.
The expectancy life in the upper bound temperature (Point A and
Point B) is three years or more.
Please refer to External View for the position of Point A and Point B.
In case of with Chassis and Cover, please contact our sales offi ce
for getting more information.
Remarks:
Please be careful of electric shock or earth leakage in case of
*
temperature measurement, because Point A and Point B is live
potential.
Please refer to 3.4 if you want to extend the longevity of the ex-
*
pectancy life.
CN1
d
LFA-24
2
CN1
d
2
d
2
d2
Fig.3.1 Installation method
d2
=4mm min
d2
=8mm min
d1
Table 3.1 Temperatures of Point A, Point B LFA10F-
Mounting
Method
A
B
C
D
E
F
A,B,C,D,E,F Forced air
Cooling
Method
Convection
Convection
Convection
Convection
Convection
Convection
Load factor
20%<Io[100% 70 84
Io[20% 75 79
20%<Io[100% 70 81
Io[20% 73 77
20%<Io[100% 76 80
Io[20% 76 77
20%<Io[100% 70 78
Io[20% 75 77
20%<Io[100% 73 84
Io[20% 76 79
20%<Io[100% 74 80
Io[20% 76 78
70%<Io[100% 75 75
Io[70% 75 75
Max temperature
Point A[C] Point B[C]
O
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