Remote Sense Leads - Agilent Technologies 66311A User Manual

3 - Installation
The output connector accepts wires sizes from AWG 22 to AWG 12. Disconnect the mating plug to make
your wiring connections. When the sense wire connections are complete, set the Remote/Local switch on
the back of the unit to Remote (switch is out). Remote sensing is illustrated in figure 3-2.

Remote Sense Leads

Testing has verified stable performance with the sense leads connected up to 20 inches from the phone.
However, for optimum performance, connect the sense leads as close as possible to the phone under test.
To minimize inductance, connect the sense leads as a separate twisted pair.
The sense leads are part of the dc source's feedback path and must be kept at a low resistance (less than
several ohms) to maintain optimal performance. Connect the sense leads carefully so that they do not
become open-circuited. If the sense leads are left unconnected or become open during operation, the dc
source will regulate at the output terminals, resulting in a 3% to 5% increase in output over the
programmed value. Shorting the sense leads forces the dc source to its maximum voltage, which will trip
the overvoltage protection circuit if it is enabled.
Connect the remote sense leads only to the remote sense connections at the output connector and at the
location on the test fixture where you want to sense the output voltage. There must be not be any
continuity from the sense leads to earth ground or from the sense leads to the output leads other than at
the test fixture. To check for continuity, unplug the output connector from the dc source and temporarily
disconnect the sense leads from the phone contacts. Use an ohmmeter and check for continuity between
the sense and load leads and between the sense leads and ground. Poor transient response will result if
continuity exists.
Figure 3-3 shows how to connect remote sense leads and load leads when external disconnect relays are
included in the load path.
20
HP 66311A OUTPUT
CONNECTOR
-S - + +S
TWIST PAIR
Figure 3-2. Remote Sense Connections
SENSE
Local
Remote
SENSE
SWITCH OUT
TWIST LEADS
+
_
WIRE RESISTANCE
LOAD