HP 654 A Series Operating Manual page 41

Figure 4-6. Connecting Power Supplies in Auto-Parallel
Program Slave 2 OVP to the Maximum Level.
The following technique minimizes the chance
that the slave 2 OVP circuit will trip.
1. Program the OVP level of the master and of slave 1 to the desired protection level (below
the maximum level specified in Table l-2b).
2. Program the OV protection level of slave 2 to its maximum value.
Enable OCP on the Master.
You can do this if the combination of all three supplies is being
used in the CV mode and the CC mode is only being used as a current limit. Enable OCP on
the master supply. If the OVP on either slave trips it will drive the master into CC mode,
thereby tripping its OCP. This will shut down all three supplies. This technique will work
unless the system is programmed for very low (0.5 to 1.5) output voltages.
Insert Protection Diodes.
If you connect the slave 2 supply to the load through a series diode
(see Figure 4-7), its OVP circuit will not draw current from other supplies. Be certain to
increase the programmed CV level of slave 2 by at least 0.7 V to compensate for the voltage
drop in the diode.
4-10 User Connections and Considerations
Auto-Parailei Operation