MPE DP SERIES II, Operating And Service Manual

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3.3 Remote Sensing
Remote sensing is available for models 1000 Vdc and below. This feature is used to improve the
degradation of regulation which will occur at the load when the voltage drop in the connecting
wires is appreciable. This is done by configuring the power supply, master and/or slave module,
for remote sensing as described in Section 3.1.1.3 and 3.1.2.2 for DPD and DPA Series power
supplies, respectively. Using a pair of #20 AWG wires, connect terminal 2 of JS2 to the positive
terminal of the load and connect terminal 1 of JS2 to the negative terminal of the load. Figure
3.25 illustrates standard output sensing and remote output sensing when the power supply is
configured for series master/slave operation.
Enabling remote sense activates the remote sense lead detector. The remote sense lead detector
checks that the remote sense leads have been connected to the load. With the power supply
configured for remote sensing and upon enabling power output, the sense location is initially set
to local. The sense location is switched to remote upon reaching 7.5% of full scale output
voltage. If the voltage detected is greater than 4.5% of full scale output voltage, the sense
location remains remote; if the output voltage detected is less than 4.5%, then the sense location
will automatically revert back to local.
The remote sense indicator on the front panel will flash when the remote sense configuration has
been selected and the power supply is using local sense. This can occur if the output voltage
never exceeds 7.5% of full scale output voltage or the remote sense lead detector has determined
sense leads are not connected. The remote sense indicator will remain flashing until the remote
sense detector has detected the presence of remote voltage within the limits described above.
3.4 External Programming
DP series supplies allow voltage, current, voltage trip, and current trip to be programmed from a
remote location. Programming can be accomplished either by resistive, voltage, or current
programming circuits.
Figure 3.26 illustrates the three alternatives for programming the voltage set point. The method
applies equally to programming set point current, over voltage trip, and over current trip.
3.4.1 Resistive Programming
Resistive programming requires connection of an external potentiometer or resistors between
terminals 21, 3, and 1 of JS1. Terminal 21 is a 10.0 V precision reference, terminal 1 is the
reference ground, and terminal 3 is the voltage set point input. Like front panel rotary control,
the precision reference produces a voltage across the potentiometer or resistors which is then
used to produce the voltage set point. Metal film resistors or a wire wound potentiometer will
result in the lowest temperature coefficient.
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