Keysight 1143A Manual

User and
Service Guide
Publication number 01143-97000
First edition, June 2000
1143A
Probe Offset Control
and Power Module

1143A Probe Offset Control
and Power Module
The 1143A Probe Offset Control and Power Module is an alternate
control and power source for active probes. When an active probe
cannot be powered from a connector at the front of the oscilloscope,
the module is used to provide power, local offset control, and a
remote offset interface. Following below are its main features. See
chapter 2 for full characteristics.
•Power and control for two probes
•+17.3 Vdc and −17.3 Vdc at 300 mA each
•Offset current source of ±5 mA for each probe
•Remote input for offset control
Accessories Supplied
The following accessories are supplied.
•Power cable
•User and Service Guide
Accessories Available
The following accessories can be ordered.
•01143-61602, 1.5-meter (59-inch) probe power extension cable
(Order with the module as Option 001.)
Options Available
The following options are available.
•Option 001, 1.5-meter (59-inch) probe power extension cable
•Option 0B1, Additional User and Service Guide
2

Service Strategy
The service strategy for the 1143A Probe Offset Control and Power
Module is for field repair to the component level. See chapter 2,
"Service," for further information.
3

In This Book
This book provides use and service documentation for the 1143A Probe
Offset Control and Power Module. It is divided into two chapters.
Chapter 1 shows you how to set up and operate the instrument, both locally
and remote.
Chapter 2 provides service information. Included is how to test the supply
performance, how and when to make adjustments, and how to troubleshoot
and repair the instrument.
4

Contents
1 Operating the Power Module
To inspect the power module 9
To check power requirements 11
To set the line voltage selection 11
To set up the power module 12
To use local offset 13
Remote Offset Input 14
2Service
General Information 20
Performance Characteristics 20
Operating Characteristics 20
General Characteristics 21
Recommended Test Equipment 23
Service Strategy 23
To clean the instrument 23
To return the instrument to HP for service 24
Testing Performance 25
Test Interval 25
Equipment Required 25
To test output voltages 26
Making Adjustments 27
Safety 27
Adjustment Interval 27
Equipment Required 27
To prepare the equipment 29
To adjust power supply voltages 29
To adjust power supply current limits 30
To adjust offset zero 31
5

Troubleshooting and Repair 32
To troubleshoot the power supplies 32
To troubleshoot the offset circuitry 33
To disassemble the instrument 34
Replaceable Parts 35
Theory of Operation 44
Schematic Diagrams 47
Index 53
Contents
6

1
To inspect the power module 9
To check power requirements 11
To set the line voltage selection 11
To set up the power module 12
To use local offset 13
Remote Offset Input 14
Operating the
Power Module
7

8

Introduction
This chapter shows you how to connect and operate the 1143A Probe
Offset Control and Power Module. The following information is
covered in this chapter:
•Initial Inspection
•Power Requirements
•Line Voltage Selection
•Setting up the supply
•Using Local Offset
•Remote Offset
For additional information, read the user and service guide for the
active probe being used with the module.
To inspect the power module
Inspect the shipping container for damage.
Keep a damaged shipping container or cushioning material until the contents
of the shipment have been checked for completeness and the instrument has
been checked mechanically and electrically.
Check the accessories.
Accessories supplied are listed in the introduction of this manual, page 2.
•If the contents are incomplete or damaged notify your Agilent
Technologies sales office.
Inspect the instrument.
•If there is mechanical damage or defect, or if the instrument does not
operate properly or pass performance tests, notify your Agilent
Technologies sales office.
•If the shipping container is damaged, or the cushioning materials show
signs of stress, notify the carrier as well as your Agilent Technologies sales
office. Keep the shipping materials for the carrier’s inspection. The
Agilent Technologies office will arrange for repair or replacement at
Agilent Technologies’ option without waiting for claim settlement.
9

Figure 1
1143A Probe Offset Control and Power Module FrontPanel
Figure 2
1143A Probe Offset Control and Power Module Rear Panel
Operatingthe Power Module
To inspect the power module
10

To check power requirements
The power module requires a power source of either 90 to 132/198 to 264
Vac, 47 to 440 Hz, 40 VA maximum.
CAUTION BEFORE CONNECTING POWER TO THIS INSTRUMENT, be sure the line
voltage switch on the rear panel of the instrument is set properly.
Applying a voltage excessive to the setting may open the protective fuse.
For size, type, and part number of the fuse, see the parts list in chapter 2,
"Service."
To set the line voltage selection
Before applying power, verify the setting of the LINE SELECT switch on the
rear panel.
•If the switch is set incorrectly, set it to either 115 V or 230 V,
whichever is appropriate for the voltage in your area.
The fuse used is the same regardless of input voltage selection.
WARNING SHOCK HAZARD!
BEFORE YOU CONNECT THIS INSTRUMENT TO MAINS POWER OR LIVE
MEASURING CIRCUITS you must provide a protective earth ground.
The Mains plug must be inserted in a socket outlet provided with a
protective earth contact.
Do not use an extension cord (power cable) without a protective conductor
(grounding). Grounding one conductor of a two-conductor outlet does not
provide an instrument ground.
Failure to provide a protective earth ground could result in a shock hazard if
there is a failure in this instrument or equipment connected to it.
This instrument isprovided with a three-wire power cable. When connected to
an appropriate ac power outlet, this cablegrounds the instrument cabinet.The
type of power cable plug shipped with theinstrumentdependson the country of
destination.
Operating the Power Module
To check power requirements
11

To set up the power module
The following paragraphs cover system preparation using the 1143A Probe
Offset Control and Power Module.
1Set the line voltage selection.
2Use the power cable to connect the power module to the ac mains.
3Connect the probe power cable to a Power connector on the front
panel of the power module.
Red dots on the cable connector housing and power module are aligned with
the connector keys. Align the dots when inserting the cable connector into
the power connector.
CAUTION The probe power cable connector automatically locks in the mating power
connector. To separate the connectors, you must pull on the knurled part of
the cable connector housing. This releases the lock. If you pull on the cable,
the connectors won’t release and you may damage the connector or cable.
4Connect the output of the probe to the input of the oscilloscope or
other instrument.
See Also The User and Service Guide for the active probe being used.
Operatingthe Power Module
To setup the power module
12

To use local offset
This section defines the operating functions of the 1143A Probe Offset
Control and Power Module. Set the controls that correspond to the Power
connector being used.
1Turn on the power for the module.
2Set the appropriate Remote/Local switch.
•To control the probe offset voltage with the power module, set the switch
to Local.
•To control the probe offset voltage remotely, set the switch to Remote and
go to "Remote Offset Input" on the next page.
3With Local control, set the appropriate Zero/Variable switch.
•To enable the local offset control, set the switch to Variable.
•To disable the local offset control, set the switch to Zero.
4Connect the probe to the signal to be measured.
5If you are using Variable offset, adjust the Coarse and Fine offset
controls so the desired part of the signal is displayed on the
oscilloscope.
When the knobs are turned clockwise, the output of the probe goes positive.
For example, when using the probe with an oscilloscope, when the trace
moves up, the horizontal center line of the screen represents a more negative
voltage. This represents a negative offset.
If you intend to use the probewith an instrument other thanan oscilloscope,
you may find it easier to set up the probe with an oscilloscopefirst. This allows
you toset the probe offset so the output of the probe is compatible withthe
signalrequirements of the otherinstrument. After set-up, connect the output of
the probe to theinputof theother instrument.
Operating the Power Module
To use localoffset
13

Remote Offset Input
For automatic test applications, the offset provided by the 1143A Probe
Offset Control and Power Module can be remotely controlled through a
connector on the rear panel of the module.
Remote Connection
The remote connection is through a standard 9-pin, female, D-subminiature
connector. This style is the same as that used on some personal computer
monitor cables, which provides an economical way to connect the remote
input to the controller interface on an automatic test system. The following
table gives the connections.
Table 1 Remote InputConnections
Pin Function Connector
1N.C.
2 Probe 1 offset common
3N.C.
4 Probe 2 offset common
5 Shield
6N.C.
7 Probe 1 offset
8N.C.
9 Probe 2 offset
Operating Range
The remote variable offset can be used when the Local/Remote function is set
to Remote. The remote inputs for the two probe connectors are separate.
The following conditions apply:
•The remote offset input range is −10 to +10 Vdc. This provides a current
of −5 to +5 mAdc at the probe connector. With the 54701A Active Probe,
this provides an offset of −57.5 to +57.5 Vdc referenced to the probe tip.
•A positive, remote voltage input provides a negative offset in the probe.
The output of the probe goes positive. A negative, remote voltage input
Operatingthe Power Module
Remote Offset Input
14

provides a positive offset in the probe. The output of the probe goes
negative.
•The offset voltage must be referenced to the appropriate (Probe 1 or
Probe 2) offset common of the remote input connector.
•To eliminate offset when using remote, the remote offset input must be set
to 0.0 V, disconnected, or grounded.
To minimize dc offset errors andpotential noise coupling caused byground
loops,electrically isolate all connections between the remoteinputconnector
and the controllingsystem.
Operating the Power Module
RemoteOffsetInput
15

16

2
General Information 20
Performance Characteristics 20
Operating Characteristics 20
General Characteristics 21
Recommended Test Equipment 23
Service Strategy 23
To clean the instrument 23
To return the instrument to Agilent Technologies for service 24
Testing Performance 25
Test Interval 25
Equipment Required 25
To test output voltages 26
Making Adjustments 27
Safety 27
Adjustment Interval 27
Equipment Required 27
To prepare the equipment 29
To adjust power supply voltages 29
To adjust power supply current limits 30
To adjust offset zero 31
Troubleshooting and Repair 32
To troubleshoot the power supplies 32
To troubleshoot the offset circuitry 33
To disassemble the instrument 34
Replaceable Parts 35
Theory of Operation 44
Schematic Diagrams 47
Service
17

18

Introduction
This chapter provides service information for the 1143A Probe Offset
Control and Power Module. The following topics are included in this
chapter:
•Specifications and Characteristics
•Recommended Test Equipment
•Repair Strategy
•Returning to Agilent Technologies for Service
•Testing Performance
•Making Adjustments
•Troubleshooting
•Replacing Parts
•Theory of Operation
•Schematics
19

General Information
This section covers general information to be used for servicing the
1143A Probe Offset Control and Power Module.
Performance Characteristics
The following are the performance characteristics for the 1143A. These
characteristics are nominal and non-warranted.
Table 2 Performance Characteristics
Supply Output Voltage +17.3 Vdc ±500 mV
−17.3 Vdc ±500 mV
Supply Current
(foreachsupply) 300mA
Offset Current
(for each probe) Variable from 0to±5 mA
Operating Characteristics
The following are the operating characteristics for the 1143A.
Table 3 Operating Characteristics
Number of probes operated 2
Controls
(for each probe) Remote/Local
Zero/Variable offset
Coarse and Fineoffset
Remote Offset Input
(for each probe) ±10 V for ±5 mAoffset current
20