Vicor 4kW MegaPAC-EL AC-DC Switchers - Manual (Page 22)

UG:108 vicorpower.com Applications Engineering: 800 927.9474 Page 22
Interface Connections (Cont.)
For DualQPACs, the +Sense pins are available on connectors designated as J1A-3 and
J1B-3 for outputs A and B, respectively. –Sense pins are on J1A-6 and J1B-6, respectively.
Reminder: Only units with Autosense will automatically operate in Local Sense
mode if no sense connections are made. It will operate in remote sense mode if
remote sense connections are made. Units without Autosense MUST have sense
connections (Local or Remote) to their respective output for the unit to
operate properly.
External Trim (P2-5)
Output voltage can be trimmed using an optional factory-installed Trim potentiometer
or with the Trim pin (see Figure 11). The Trim potentiometer is located on the
ConverterPAC. If the Trim potentiometer has not been ordered, the Trim pin must
be used. When using the Trim pin, the Trim limits are determined by the DC to DC
converter used on the ConverterPAC. Maximum Trim ranges are 10% above the
nominal converter voltage and 50% below the nominal converter voltage as measured
from the output studs or output connector of the power supply.
Note: The combined effects of module trim up, remote sense and dynamic load step may
cause the module to trip OVP. Recovering from OVP will require cycling input power to
the MegaPAC.
The Trim pin on P2 can be used to control the output voltage. It is referenced to the
-Sense pin on P2 and can be controlled by either a resistor network or an external
voltage source. To increase an output voltage above its nominal, it is necessary to
increase the voltage at the Trim pin above the internal reference voltage (Vref). The
reverse is true to decrease an output voltage.
Note: Converters are sometimes pretrimmed at the factory if a nonstandard output
voltage is requested. Standard voltages include 2 V, 3.3 V, 5 V, 12 V, 15 V, 24 V, 28 V, and
48 V. If using a nonstandard voltage, or if a ConverterPAC is ordered with a Trim option,
the resistor calculations will differ from those below.
Please consult the factory for assistance.
Figure 10.
Sense Leads
(Remote Sense)
Load
(Local Sense)
+P +Out
P2-7 +Sense
P2-6 -Sense
-P -Out
Use 22-24 AWG
Twisted Pair Wires
End of Life - Not Recommended for New Designs