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Chapter 1
Installation and Preparation
Connecting an Electrolytic Capacitor Across the Load
If the cabling is largely inductive, it may be necessary to connect an electrolytic capacitor across
the load. If you run into this problem, the following symptoms may appear:
•
The output of the power supply is oscillating. If very long wires are used to connect the
load, the inductive and capacitive components of the cable can cause phase shifting that
results in oscillation at the output. You can reduce this effect by shortening the load cables.
However, if this does not rectify the problem, connect and electrolytic capacitor across the
load.
•
If the load current is changing rapidly in a pulse-shaped pattern, the output voltage may
fluctuate due to inductance in the cabling. You can reduce the inductance component by
twisting the load cables, which stabilizes the voltage. However, if this does not rectify the
problem, connect an electrolytic capacitor across the load.
Inserting a Mechanical Switch Between the RMX Programmable
Power Supply and the Load
If you want to connect and disconnect the load using a mechanical switch that is inserted
between the RMX programmable power supply and the load, be sure to include switches in the
sensing cables as shown in the following figure. Also make sure to turn on and off the load cable
and sensing cables simultaneously. Before you turn the mechanical switch on or off, be sure to
turn the output or the POWER switch off.
Figure 1-25.
Mechanical Switch in a Sensing Cable
Table 1-3.
Electrolytic Capacitor with RMX Programmable Power Supplies
RMX-4120
RMX-4124
RMX-4121/
RMX-4125
RMX-4122/
RMX-4126
RMX-4123/
RMX-4127
36 V or more
96 V or more
276 V or more
780 V or more
Capacitance: 0.1
μ
F to a few hundred
μ
F.
Withstand voltage: At least 120% of the rated output voltage of the RMX programmable
power supply.
Load
S
+
–
C
+
–
+S
–S
+
–
