Agilent Technologies 6612B, Service Manual, Page: 47 / 74

47
4
Principles of Operation
Introduction
This section describes the different functional circuits used in the dc power supply models covered in this
manual. First, the I/O external signals that connect to the Agilent power supply are described. Next, the
overall block diagrams for the dc power supply are described in detail.
The simplified block diagrams in this section show the major circuits on the dc power supply as well as
the signals between circuits. They also show the reference designations of some of the components in the
functional circuit. These same reference designators are shown in the schematic diagrams in Section 6.
I/O Interface Signals
Table 4-1 describes the interface signals between the power supply and the end user (or other external
circuits and devices).
Table 4-1. Power Supply Interface signals
Connector Signal Description
Front panel outputs +OUT
-OUT Positive DC output voltage
Negative DC voltage (or return)
Rear panel
output/sense screw
terminals +OUT
-OUT
+ sense
- sense
common Positive DC output voltage
Negative DC voltage (or return)
+OUT sensing terminal
1
-OUT sensing terminal
1
connected to ground conductor
1
Set SENSE switch to "Remote" when using the sensing
terminals.
INH/FLT
connector
pin 1
pin 2
pin 3
pin 4
FLT/INH mode
2
Digital I/O mode
FLT output OUT 0
FLT Common OUT 1
INH Input IN 2/OUT 2
INH Common Common
2
as-shipped configuration
RS-232 connector XON-XOFF
RTS-CTS
DTR-DSR
NONE uses ASCII control codes DC# and DC1
uses Request-To-Send and Clear-To-Send lines
uses Data-Terminal-Ready and Data-Set-Ready lines
there is no flow control
GPIB connector GPIB /IEEE 488 Provides the interface to an external GPIB controller
Ac input connector ac mains Can be 100 Vac, 120 Vac, 220 Vac or 240 Vac Input