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Chapter 3
External Control
Controlling the Output Voltage
This section explains how to control the output voltage using an external voltage (Vext) or an
external variable resistor (Rext) of approximately 10 k
Ω
.
If no load is connected, it takes some time for the output voltage to decrease. There may be a
delay between when you request a new voltage with Vext or Rext and when it shows up on the
output terminals.
Caution
Risk of electric shock. If neither output terminal is tied to chassis ground,
the reinforced or double insulation of Vext or Rext and the connected cable must be
greater than or equal to the isolation voltage of the RMX programmable power supply.
Refer to Appendix A,
, for the isolation voltage of your model.
If one of the output terminals is connected to chassis ground, the insulation of Vext or
Rext and the connected cable must have a reinforced or double insulation with a
capacity greater than or equal to the maximum output voltage relative to the chassis
When using shielded cables for the connection, for uncovered sections of the shielded
cables, use insulation tubes to secure reinforced or double insulation with a capacity
greater than or equal to the isolation voltage of the RMX programmable power supply.
Control Using an External Voltage (Vext)
To use an external voltage (Vext) to control the output voltage, set CONFIG setting CF06 to ON
to enable control of the output voltage using an external voltage.
The output voltage (Eo) varies in the range of 0 to the rated output voltage (Ertg) when the
external voltage (Vext) is changed in the range of 0 to 5 V (CF07: Lo) or in the range of 0 to 10 V
(CF07: Hi).
Caution
The Vext cable must not be referenced/connected to the chassis ground
terminal. The signal must be floating relative to ground. Connecting/referencing this
signal to ground may cause the cable to be damaged. Refer to Figures 3-10 and 3-11
for more information.
Pay careful attention to the polarity of Vext. Do not apply a voltage of 10.5 V or
greater, or a reverse voltage across the external voltage control pins.
External voltage (Vext)
0 to 5 V (CF07: Lo)
External voltage (Vext)
0 to 10 V (CF07: Hi)
Eo = Ertg × Vext/5 (in V)
Vext = 5 × Eo/Ertg (in V)
Eo = Ertg × Vext/10 (in V)
Vext = 10 × Eo/Ertg (in V)
