1.6 Output ripple and ripple noise
¡
Output ripple noise may be influenced by measurement environ-
ment, measuring method fig.1.1 is recommended.
+Vout
-Vout
Load
150mm
C
2
C
1
Osilloscope/
Ripple noise meter
Bw:20MHz
Differential probe
+
C
1 :
Film capacitor 0.1μF
C
2 :
Aluminum electrolytic capacitor 22μF
Fig.1.1 Measuring method of Ripple and Ripple Noise
Remarks :
When GND cable of probe with flux of magnetic force from power
supply are crossing, ripple and ripple noise might not measure
correctly.
Please note the measuring environment.
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 Hi-
Pot tester with the timer because it may generate voltage a few
times higher than the applied voltage, at ON/OFF of a timer.
¡
When you test units for isolation between the input and output, or
between output and terminal FG, short-circuit between output and
remote ON/OFF connector.
1.8 Reducing standby power
¡
Burst operation at light loading, the internal switch element is in-
termittent operated, and the switching loss is decreased.
The specification of the Ripple/Ripple Noise changes by this in-
termittent operation. The value of the Ripple / Ripple Noise when
intermittent operates changes in the input voltage and the output
current.
¿
LHA100F, LHA150F, LHA300F
¡
In option -R2, standby power with remote OFF is lower than the
one with no load.
Please refer to instruction manual 6.1.
2 Series Operation and
Parallel Operation
2.1 Series Operation
¡
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 current among power supplies
that are serially connected. Please make sure that no current ex-
ceeding the rated current flows into a power supply.
(a)
(b)
Load
Power
Supply
+
-
+
-
Power
Supply
Load
Load
Power
Supply
+
-
+
-
Power
Supply
Fig.2.1 Examples of connecting in series operation
2.2 Parallel Operation
¡
Parallel operation is not possible.
¡
Redundancy operation is available by wiring as shown below.
I
2
I
1
I
3
-
+
+
-
Load
Power
Supply
Power
Supply
Fig.2.2 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 Open Frame
Instruction Manual
LHA-26
May 26, 2022
