Fluke 45 Service Manual

Dual Display Multimeter

Service Manual

For IEC 1010 Meters Only

PN 609203 March 1999 Rev.1, 1/04

LIMITED WARRANTY & LIMITATION OF LIABILITY

Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service. The warranty period is one year and begins on the date of shipment. Parts, product repairs and services are warranted for 90 days. This warranty extends only to the original buyer or end-user customer of a Fluke authorized reseller, and does not apply to fuses, disposable batteries or to any product which, in Fluke’s opinion, has been misused, altered, neglected or damaged by accident or abnormal conditions of operation or handling. Fluke warrants that software will operate substantially in accordance with its functional specifications for 90 days and that it has been properly recorded on non-defective media. Fluke does not warrant that software will be error free or operate without interruption.

Fluke authorized resellers shall extend this warranty on new and unused products to end-user customers only but have no authority to extend a greater or different warranty on behalf of Fluke. Warranty support is available if product is purchased through a Fluke authorized sales outlet or Buyer has paid the applicable international price. Fluke reserves the right to invoice Buyer for importation costs of repair/replacement parts when product purchased in one country is submitted for repair in another country.

Fluke’s warranty obligation is limited, at Fluke’s option, to refund of the purchase price, free of charge repair, or replacement of a defective product which is returned to a Fluke authorized service center within the warranty period.

To obtain warranty service, contact your nearest Fluke authorized service center or send the product, with a description of the difficulty, postage and insurance prepaid (FOB Destination), to the nearest Fluke authorized service center. Fluke assumes no risk for damage in transit. Following warranty repair, the product will be returned to Buyer, transportation prepaid (FOB Destination). If Fluke determines that the failure was caused by misuse, alteration, accident or abnormal condition of operation or handling, Fluke will provide an estimate of repair costs and obtain authorization before commencing the work. Following repair, the product will be returned to the Buyer transportation prepaid and the Buyer will be billed for the repair and return transportation charges (FOB Shipping Point).

THIS WARRANTY IS BUYER’S SOLE AND EXCLUSIVE REMEDY AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. FLUKE SHALL NOT BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES, INCLUDING LOSS OF DATA, WHETHER ARISING FROM BREACH OF WARRANTY OR BASED ON CONTRACT, TORT, RELIANCE OR ANY OTHER THEORY.

Since some countries or states do not allow limitation of the term of an implied warranty, or exclusion or limitation of incidental or consequential damages, the limitations and exclusions of this warranty may not apply to every buyer. If any provision of this Warranty is held invalid or unenforceable by a court of competent jurisdiction, such holding will not affect the validity or enforceability of any other provision.

To locate an authorized service center, visit us on the World Wide Web: www.fluke.com or call Fluke using the phone numbers listed below:

USA and Canada: 1-888-99-FLUKE (1-888-993-5853) Europe: +31 402-675-200 Japan: +81-3-3434-0181 Singapore: +65-738-5655 Anywhere in the world: +1-425-446-5500

Fluke Corporation Fluke Europe B.V. P.O. Box 9090 P.O. Box 1186 Everett, WA 98206-9090 5602 BD Eindhoven U.S.A. The Netherlands

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Chapter Title Page

1 Introduction and Specifications ........................................................ 1-1

1-1. Introduction........................................................................................... 1-3

1-2. Operating Instructions .......................................................................... 1-3

1-3. Options and Accessories....................................................................... 1-3

1-4. Organization of the Service Manual..................................................... 1-4

1-5. Conventions.......................................................................................... 1-5

1-6. Specifications........................................................................................ 1-6

2 Theory of Operation ........................................................................... 2-1

2-1. Introduction........................................................................................... 2-3

2-2. Functional Block Description............................................................... 2-3

2-3. Power Supply.................................................................................... 2-3

2-4. Analog Measurement Processor....................................................... 2-3

2-5. Input Protection Circuit.................................................................... 2-3

2-6. Input Signal Conditioning ................................................................ 2-3

2-7. Analog-to-Digital (A/D) Converter.................................................. 2-3

2-8. Serial Communication (Guard Crossing)......................................... 2-3

2-9. Digital Kernel................................................................................... 2-5

2-10. Display Assembly............................................................................. 2-5

2-11. IEEE-488 Interface Option (-05)...................................................... 2-5

2-12. Battery Pack Option (-01) ................................................................ 2-5

2-13. Detailed Circuit Description................................................................. 2-5

2-14. Power Supply Circuit Description.................................................... 2-5

2-15. Raw DC Supply............................................................................ 2-6

2-16. 5-Volt Switching Supply.............................................................. 2-6

2-17. Inverter......................................................................................... 2-7

2-18. Analog Measurement Processor....................................................... 2-7

2-19. Input Protection................................................................................ 2-10

2-20. Input Signal Conditioning................................................................ 2-10

2-21. Relays........................................................................................... 2-11

2-22. DC Volts ...................................................................................... 2-12

2-23. Ohms............................................................................................ 2-12

2-24. 100 MΩ and 300 MΩ Ranges...................................................... 2-14

2-25. AC Volts ...................................................................................... 2-14

Service Manual

2-26. DCmA.......................................................................................... 2-15

2-27. ACmA.......................................................................................... 2-15

2-28. Amps............................................................................................ 2-15

2-29. Diode/Continuity Test.................................................................. 2-15

2-30. Frequency..................................................................................... 2-15

2-31. Active Filter...................................................................................... 2-16

2-32. A/D Converter.................................................................................. 2-17

2-33. Serial Communication (Guard Crossing)......................................... 2-18

2-34. Digital Kernel................................................................................... 2-18

2-35. RS-232 Interface.......................................................................... 2-19

2-36. Microprocessor ............................................................................ 2-19

2-37. EEROM........................................................................................ 2-19

2-38. RAM............................................................................................. 2-20

2-39. ROM............................................................................................. 2-20

2-40. IEEE-488 Option Connections..................................................... 2-20

2-41. Display Assembly............................................................................. 2-20

2-42. Main Assembly Connector........................................................... 2-20

2-43. Front Panel Switches.................................................................... 2-20

2-44. Display......................................................................................... 2-21

2-45. Beeper Drive Circuit.................................................................... 2-21

2-46. Watchdog Timer and Reset Circuit.............................................. 2-21

2-47. Display Controller with FIP......................................................... 2-22

3 General Maintenance ......................................................................... 3-1

3-1. Introduction........................................................................................... 3-3

3-2. Warranty Repairs and Shipping Information........................................ 3-3

3-3. General Maintenance Information........................................................ 3-3

3-4. Required Equipment......................................................................... 3-3

3-5. Power Requirements......................................................................... 3-3

3-6. Static Safe Handling......................................................................... 3-3

3-7. Cleaning................................................................................................ 3-4

3-8. Fuse Test and Replacement.................................................................. 3-4

3-9. Line Fuse .......................................................................................... 3-4

3-10. Current Input Fuses.......................................................................... 3-4

3-11. Testing Current Input Fuses......................................................... 3-4

3-12. Replacing the 500 mA and 440 mA Input Fuses (F1 and F5)...... 3-5

3-13. Replacing the 10 A Input Jack Fuse (F2)..................................... 3-6

3-14. Disassembly Procedures....................................................................... 3-7

3-15. Remove the Meter Case.................................................................... 3-7

3-16. Remove Handle and Mounting Brackets.......................................... 3-7

3-17. Remove the Front Panel Assembly.................................................. 3-8

3-18. Remove the Display PCA................................................................. 3-8

3-19. Remove the IEEE-488 Option.......................................................... 3-9

3-20. Remove the Main PCA..................................................................... 3-9

3-21. Remove the Analog Measurement Processor Shields...................... 3-9

3-22. Remove the Rms PCA...................................................................... 3-10

3-23. Remove the Battery Option.............................................................. 3-10

3-24. Disconnect Miscellaneous Chassis Components ............................. 3-10

3-25. Assembly Procedures............................................................................ 3-10

3-26. Install Miscellaneous Chassis Components..................................... 3-10

3-27. Install the Battery Option................................................................. 3-11

3-28. Install the Rms PCA......................................................................... 3-11

3-29. Install the Analog Measurement Processor Shields......................... 3-11

3-30. Install the Main PCA........................................................................ 3-11

Contents (continued)

3-31. Install the IEEE-488 Option............................................................. 3-12

3-32. Assemble the Front Panel Assembly................................................ 3-12

3-33. Install the Front Panel Assembly...................................................... 3-15

3-34. Install the Handle and Mounting Brackets....................................... 3-15

3-35. Install the Meter Case....................................................................... 3-15

4 Performance Testing and Calibration............................................... 4-1

4-1. Introduction........................................................................................... 4-3

4-2. Required Equipment............................................................................. 4-3

4-3. Performance Tests ................................................................................ 4-4

4-4. Front Panel Calibration......................................................................... 4-7

4-5. Introduction ...................................................................................... 4-7

4-6. Entering Calibration Mode............................................................... 4-8

4-7. Exiting Calibration Mode................................................................. 4-9

4-8. DC Volts Calibration (Front Panel) ................................................. 4-9

4-9. AC Volts Calibration (Front Panel) ................................................. 4-9

4-10. DC and AC Milliamp Calibration (Front Panel).............................. 4-9

4-11. DC and AC Amps Calibration (Front Panel) ................................... 4-11

4-12. Ohms Calibration (Front Panel)....................................................... 4-11

4-13. Alternate Ohms Calibration (Front Panel)....................................... 4-13

4-14. Continuity/Hysteresis Threshold Calibration (Front Panel) ............ 4-13

4-15. Frequency Calibration (Front Panel)................................................ 4-13

4-16. C2 Adjustment Procedure ................................................................ 4-13

4-17. Editing the Prompt for Different Calibration Points........................ 4-14

4-18. Calibration Using the Computer Interface............................................ 4-15

4-19. Setup................................................................................................. 4-15

4-20. RS-232 Interface.......................................................................... 4-15

4-21. IEEE-488 Interface....................................................................... 4-16

4-22. The Calibration Procedure ............................................................... 4-18

4-23. DC Volts Calibration (Computer Interface)..................................... 4-19

4-24. AC Volts Calibration (Computer Interface)..................................... 4-19

4-25. DC and AC Milliamps Calibration (Computer Interface)................ 4-19

4-26. DC and AC Amps Calibration (Computer Interface)....................... 4-19

4-27. Ohms Calibration (Computer Interface)........................................... 4-19

4-28. Continuity/Hysteresis Threshold Calibration (Computer Interface) 4-20

4-29. Frequency Calibration (Computer Interface)................................... 4-20

4-30. Concluding Calibration Using the Computer Interface.................... 4-20

4-31. Alternate Ohms Calibration (Computer Interface)........................... 4-20

5 Diagnostic Testing and Troubleshooting ......................................... 5-1

5-1. Introduction........................................................................................... 5-3

5-2. Servicing Surface-Mount Assemblies .................................................. 5-3

5-3. Error Codes........................................................................................... 5-4

5-4. General Troubleshooting Procedures ................................................... 5-10

5-5. Power Supply Troubleshooting........................................................ 5-10

5-6. Raw DC Supply............................................................................ 5-10

5-7. 5-Volt Switching Supply.............................................................. 5-11

5-8. Inverter......................................................................................... 5-12

5-9. Analog Troubleshooting................................................................... 5-13

5-10. Uart Test....................................................................................... 5-13

5-11. DC Volts Troubleshooting........................................................... 5-14

5-12. AC Volts Troubleshooting........................................................... 5-14

5-13. Ohms Troubleshooting................................................................. 5-14

5-14. Digital Troubleshooting........................................................................ 5-15

iii

Service Manual

5-15. Display Assembly Troubleshooting...................................................... 5-17

5-16. Calibration Failures .............................................................................. 5-19

5-17. Introduction...................................................................................... 5-19

5-18. Calibration-Related Components..................................................... 5-20

5-19. Calibration Interrelationships........................................................... 5-21

5-20. Retrieving Calibration Constants..................................................... 5-21

5-21. Replacing the EEROM A1U5.......................................................... 5-21

6 List of Replaceable Parts................................................................... 6-1

6-1. Introduction........................................................................................... 6-3

6-2. How to Obtain Parts.............................................................................. 6-3

6-3. How to Contact Fluke........................................................................... 6-4

6-4. Manual Status Information................................................................... 6-4

6-5. Newer Instruments................................................................................ 6-4

6-6. Parts ...................................................................................................... 6-4

7 Option -01 Battery Pack..................................................................... 7-1

7-1. Introduction........................................................................................... 7-3

7-2. Specifications........................................................................................ 7-3

7-3. Theory of Operation ............................................................................. 7-3

7-4. Functional Block Description........................................................... 7-3

7-5. Switching Power Supply.............................................................. 7-5

7-6. Cycle/Float Charge Rate Switch.................................................. 7-5

7-7. Low Battery Indicator Detector................................................... 7-5

7-8. Low Battery Disconnect............................................................... 7-5

7-9. Constant Voltage Trickle Charger............................................... 7-6

7-10. Other Circuits............................................................................... 7-6

7-11. General Maintenance............................................................................ 7-6

7-12. Removal............................................................................................ 7-6

7-13. Installation........................................................................................ 7-7

7-14. Performance Testing............................................................................. 7-9

7-15. General Operability.......................................................................... 7-9

7-16. Low Battery Indicator Detector and Low Battery Disconnect Test. 7-10

7-17. Cycle/Float Charge Rate Switch Test .............................................. 7-10

7-18. Calibration ............................................................................................ 7-12

7-19. Troubleshooting.................................................................................... 7-13

7-20. Additional Tests.................................................................................... 7-14

7-21. Schematic Diagram............................................................................... 7-14

7-22. List of Replaceable Parts...................................................................... 7-14

8 Option -05 IEEE-488 Interface............................................................ 8-1

8-1. Introduction........................................................................................... 8-3

8-2. Theory of Operation ............................................................................. 8-3

8-3. Functional Block Description........................................................... 8-3

8-4. Detailed Circuit Description............................................................. 8-3

8-5. Main Assembly Connectors......................................................... 8-3

8-6. Address Decoding Circuit............................................................ 8-3

8-7. Isolation Circuits.......................................................................... 8-4

8-8. IEEE-488 Controller .................................................................... 8-4

8-9. IEEE-488 Transceivers/Connector............................................... 8-5

8-10. General Maintenance............................................................................ 8-8

8-11. Removing the IEEE-488 Interface Option ....................................... 8-8

8-12. Installing the IEEE-488 Interface Option......................................... 8-9

Contents (continued)

8-13. Performance Testing............................................................................. 8-9

8-14. Troubleshooting.................................................................................... 8-10

8-15. Power-up Problems .......................................................................... 8-10

8-16. Communication Problems................................................................ 8-10

8-17. Failure to Select IEEE-488 Interface Option............................... 8-10

8-18. Failure to Handshake on IEEE-488 Bus ...................................... 8-11

8-19. Failure to Enter Remote............................................................... 8-11

8-20. Failure to Receive Multiple Character Commands...................... 8-12

8-21. Failure to Transmit Query Responses.......................................... 8-12

8-22. Failure to Generate an End or Identify (EOI).............................. 8-12

8-23. Failure to Generate a Service Request (SRQ).............................. 8-12

8-24. Schematic Diagram............................................................................... 8-12

8-25. List of Replaceable Parts...................................................................... 8-12

9 Schematic Diagrams .......................................................................... 9-1

Index

Service Manual

List of Tables

Table Title Page

1-1. Accessories............................................................................................................. 1-4

2-1. Analog Measurement Processor Pin Name Description........................................ 2-9

2-2. Relay Operation..................................................................................................... 2-11

2-3. Reference Resistance............................................................................................. 2-13

2-4. AC Volts Input Signal Dividers............................................................................. 2-14

2-5. Front Panel Switch Scanning................................................................................. 2-21

2-6. Display Initialization Modes.................................................................................. 2-23

3-1. Fuses.......................................................................................................................3-6

4-1. Recommended Test Equipment ............................................................................. 4-3

4-2. Performance Tests for Volts, Diode Test, Ohms, and Frequency Functions......... 4-5

4-3. Performance Tests for mA Current Functions....................................................... 4-7

4-4. Performance Tests for Current Functions.............................................................. 4-7

4-5. Front Panel Calibration.......................................................................................... 4-10

4-6. Specifications Increase with Different Calibration Points..................................... 4-15

4-7. Calibration Using the Computer Interface............................................................. 4-17

4-8. Calibration Mode Computer Interface Commands................................................ 4-21

4-9. EEROM Calibration Constants.............................................................................. 4-22

5-1. Error Codes............................................................................................................ 5-5

5-2. Power Supplies....................................................................................................... 5-11

5-3. DC Volts Troubleshooting..................................................................................... 5-14

5-4. AC Volts Troubleshooting..................................................................................... 5-15

5-5. Display Initialization.............................................................................................. 5-18

5-6. Calibration Steps and Related Components........................................................... 5-22

5-7. Components Unique to Calibration Steps.............................................................. 5-23

5-8. Calibration Hierarchy............................................................................................. 5-24

5-9. Calibration Constants............................................................................................. 5-24

6-1. Manual Status Information..................................................................................... 6-4

6-2. Final Assembly....................................................................................................... 6-5

6-3. A1 Main PCA......................................................................................................... 6-8

6-4. A1A1 True Rms PCA............................................................................................ 6-12

6-5. A2 Display PCA..................................................................................................... 6-13

7-1. Option -01 Battery Pack Final Assembly............................................................... 7-15

7-2. A4 Battery Pack PCA............................................................................................. 7-16

8-1. IEEE-488 Transceiver Control............................................................................... 8-6

8-2. Option -05 IEEE - 488 Interface Final Assembly.................................................. 8-13

vii

Service Manual

8-3. A5 IEEE-488 Interface PCA.................................................................................. 8-14

viii

List of Figures

Figure Title Page

2-1. Overall Functional Block Diagram........................................................................ 2-4

2-2. Analog Simplified Schematic Diagram.................................................................. 2-8

2-3. DC Volts 300 V Range Simplified Schematic....................................................... 2-12

2-4. Ohms Simplified Schematic................................................................................... 2-13

2-5. AC Buffer Simplified Schematic........................................................................... 2-14

2-6. DC mA and Amps Simplified Schematic............................................................... 2-16

2-7. Active Filter Simplified Schematic........................................................................ 2-17

2-8. A/D Converter Simplified Schematic .................................................................... 2-18

2-9. Command Byte Transfer Waveforms .................................................................... 2-23

2-10. Grid Control Signal Timing ................................................................................... 2-24

2-11. Grid-Anode Timing Relationships......................................................................... 2-24

3-1. Replacing the Line Fuse (F3)................................................................................. 3-5

3-2. Replacing the External 100 mA Input Fuse (F1)................................................... 3-6

3-3. Removing the Case................................................................................................. 3-7

3-4. Removing the Handle and Handle Mounting Brackets.......................................... 3-8

3-5. Assembly Details ................................................................................................... 3-13

4-1. Four Wire Configuration........................................................................................ 4-12

4-2. C2 Location............................................................................................................ 4-14

5-1. Test Point Locator.................................................................................................. 5-6

5-2. Volt Switching Supply........................................................................................... 5-12

5-3. Main Processor Timing.......................................................................................... 5-16

5-4. Display Controller to Microprocessor Signals....................................................... 5-17

5-5. Primary Display...................................................................................................... 5-18

5-6. Secondary Display................................................................................................. 5-18

6-1. Final Assembly....................................................................................................... 6-6

6-2. A1 Main PCA......................................................................................................... 6-11

6-3. A1A1 True Rms PCA............................................................................................ 6-12

6-4. A2 Display PCA..................................................................................................... 6-14

7-1. Battery Pack Option Functional Block Diagram.................................................... 7-4

7-2. Removing the Case................................................................................................. 7-7

7-3. Installing the Battery Kit........................................................................................ 7-8

7-4. Battery Pack Option Connecting Cable ................................................................. 7-9

7-5. Cycle/Float Charge Rate Switch Test.................................................................... 7-11

7-6. Unplugging the Battery Pack Connectors.............................................................. 7-13

7-7. Test Points and Adjustments.................................................................................. 7-14

Service Manual

7-8. Option-01 Battery Pack Final Assembly................................................................ 7-15

7-9. A4 Battery Pack PCA............................................................................................. 7-18

8-1. Disassembly........................................................................................................... 8-6

8-2. IEEE-488 Interface Connector............................................................................... 8-7

8-3. IEEE-488 Module Assembly.................................................................................. 8-8

8-4. IEEE-488 Interface Performance Test................................................................... 8-10

8-5. Option -05 IEEE-488 Interface Final Assembly.................................................... 8-13

8-6. A5 IEEE-488 Interface PCA.................................................................................. 8-15

9-1. A1 Main PCA......................................................................................................... 9-2

9-2. A2 Display PCA..................................................................................................... 9-8

9-3. A1A1 True Rms PCA............................................................................................ 9-10

9-4. A4 Battery PCA..................................................................................................... 9-12

9-5. A5 IEEE-488 Interface PCA.................................................................................. 9-14

Chapter 1

Introduction and Specifications

Title Page

1-1. Introduction............................................................................................. 1-3

1-2. Operating Instructions ............................................................................ 1-3

1-3. Options and Accessories......................................................................... 1-3

1-4. Organization of the Service Manual....................................................... 1-4

1-5. Conventions............................................................................................ 1-5

1-6. Specifications.......................................................................................... 1-6

1-1

Service Manual

1-2

1-1. Introduction

The Fluke 45 Dual Display Multimeter (also referred to as "the meter") is a 4-1/2-digit (30,000-count) meter with a 5-digit (100,000-count) high resolution mode designed for bench-top, field service, and system applications. The meter uses a dual vacuumfluorescent display, allowing for two types of readings from a single input. Primary and secondary displays show the user-defined readings side by side. Even though the readings are made sequentially, the displays show both readings at all times for ease of comparison.

Some features provided by the meter are:

• Computer interface operation via the RS-232 interface (included) or the IEEE-488

interface (optional). The meter is fully programmable for use on the IEEE Standard

488.1 (1987). The meter is also designed in compliance with supplemental standard IEEE-488.2 (1987).

• True rms ac

• (AC + DC) rms, calculated

• Frequency measurements to greater than 1 MHz.

Introduction and Specifications

Introduction

• 1 µV sensitivity in volts dc

• Decibels with variable reference impedance and audio power measurement

capability.

• A compare mode to determine if a measurement is within, above, or below a

designated range.

• 100,000, 30,000, and 3,000 selectable count resolution, with reading speeds of 2.5, 5,

and 20 readings per second (rps), respectively.

• Built-in self-tests with closed-case calibration (no internal adjustments).

1-2. Operating Instructions

Full operating instructions are provided in the Fluke 45 Users Manual. Reference to these instructions may be necessary during some of the maintenance and repair procedures presented in this Service Manual. For quick references, an operating instruction summary is presented on the inside of the front cover of the Service Manual. For more detailed information, refer to the Users Manual.

1-3. Options and Accessories

Three options are available. These options can be installed either at the factory or in the field. The following discussions pertain to the field-installable option kits:

• The Battery Kit (Option -01K) consists of a rechargeable, 8 V, lead-acid battery,

with battery bracket and charger assembly. The battery has a typical operating time of eight hours and is fully operable at ambient temperatures between 0 and 50ºC.

• The IEEE-488 Interface Kit (Option -05K) consists of a printed circuit assembly,

connecting cables, and mounting hardware. This option provides full programmability, external trigger input, and automated calibration. The IEEE-488 computer interface command set is identical to the RS-232 interface commands wherever possible.

• Option -15K combines Options -01K and -05K as a single kit.

1-3

Service Manual

C40 Soft carrying case. Provides padded protection for the meter. Includes a pocket for the

The Fluke 45 Dual Display Multimeter can be mounted in a standard 19-inch rack panel on either the right-hand or left-hand side using the Fluke M00-200-634 Rack Mount Kit.

Accessories for the Fluke 45 are listed in Table 1-1.

Table 1-1. Accessories

Model Description

manual and pouch for the test leads and line cord.

M00-200634

RS40 RS-232 terminal interface cable. Connects other Fluke 45 to any terminal or printer with

RS41 RS-232 modem cable. Connects the Fluke 45 to a modem. S45 QuickStart™, a PC software package, simplifies operation of the Fluke 45 when using

Y8021 Shielded IEEE-488 one-meter (39.4 inches) cable, with plug and jack at each end. Y8022 Shielded IEEE-488 two-meter (78.8 inches) cable, with plug and jack at each end. Y8023 Shielded IEEE-488 four-meter (13 feet) cable, with plug and jack at each end. QuickStart 45 is a trademark of Fluke Corporation.

Lotus is a registered trademark of Lotus Development Co. dBase III is a registered trademark of Ashton-Tate. IBM PC and IBM PC/XT are registered trademarks of International Business Machines.

Rackmount Kit. Allows meter to be mounted on either the right or left side of a standard 19-inch rack.

properly configured DTE connector (DB-25, female pins), including an IBM PC®, IBM PC/XT® or IBM PS/2 (models 25, 30, 50, P60, 70, and 80).

the RS-232 computer interface. Readings are recorded in files that can be accessed by Lotus 1-2-3®, dBase III® and other graphics packages.

1-4. Organization of the Service Manual

This manual focuses on component-level repair of the Fluke 45 Dual Display Multimeter. To that end, manual chapters are often interdependent; effective troubleshooting may require not only reference to the troubleshooting procedures in Chapter 5, but also some understanding of the detailed Theory of Operation in Chapter 2 and some tracing of circuit operation in the Schematic Diagrams presented in Chapter 9.

1-4

Often, scanning the table of contents will yield an appropriate place to start using the manual. A comprehensive table of contents is presented at the front of the manual; local tables of contents are also presented at the beginning of each chapter for ease of reference. If you know the topic name, the index at the end of the manual is probably a good place to start.

The following chapter descriptions serve to introduce the manual:

Chapter 1. Introduction and Specifications

Introduces the Fluke 45 Dual Display Multimeter, describing its features, options, and accessories. This chapter also discusses use of the Service Manual and the various conventions used in describing the meter’s circuitry. Finally, a complete set of specifications is presented.

Chapter 2. Theory of Operation

This chapter first categorizes meter circuitry into functional blocks, with a description of each block’s role in overall operation. A detailed circuit description is then given for each block. These descriptions explore operation to the component level and fully support troubleshooting procedures defined in Chapter 5.

Chapter 3. General Maintenance

Provides maintenance information covering handling, cleaning, and fuse replacement. Access and reassembly procedures are also explained in this chapter.

Chapter 4. Performance Testing and Calibrat ion

This chapter provides performance verification procedures that are tied to the specifications presented in Chapter 1. To maintain these specifications, a full calibration procedure is also presented.

Chapter 5. Diagnostic Testing and Troubleshooting

The troubleshooting procedures presented in this chapter rely closely on both the Theory of Operation presented in Chapter 2 and the Schematic Diagrams shown in Chapter 9. Chapter 3 provides access information.

Introduction and Specifications

Conventions

Chapter 6. List of Replaceable Parts

Includes parts lists for all standard assemblies. Information on how and where to order parts is also provided.

Chapter 7. Option -01 Battery Pack

Each option is allocated a separate chapter: 7 for the Battery Pack Option -01 and 8 for the IEEE-488 Interface Option -05. Option -15 incorporates both Options -01 and -05. Chapter 7 includes the full range of Service Manual topics (specifications, theory of operation, maintenance, list of replaceable parts, etc.) for the Battery Pack option. Schematic diagrams for the options are found in Chapter 9.

Chapter 8. Option -05 IEEE-488 Int erface

Includes the full range of Service Manual topics (specifications, theory of operation, maintenance, list of replaceable parts, etc.) for the IEEE-488 Interface option. Schematic diagrams for the options are found in Chapter 9.

Chapter 9. Schematic Diagrams

Includes schematic diagrams for all standard and optional assemblies. A list of mnemonic definitions is also included to aid in identifying signal name abbreviations.

1-5. Conventions

Throughout the manual set, certain notational conventions are used. A summary of these conventions follows:

• Instrument Reference

The Fluke 45 Dual Display Multimeter is usually called the "meter."

• Printed Circuit Assembly

1-5

Service Manual

The term "pca" is used to represent a printed circuit assembly and its attached parts.

• Signal Logic Polarity

On schematic diagrams, a signal name followed by a "*" is active (or asserted) low. Signals not so marked are active high.

• Circuit Nodes

Individual pins or connections on a component are specified with a dash (-) following the component reference designator. For example, pin 19 of U30 would be U30-19.

• User Notation

For front panel operation, XXX An uppercase word or symbol without parentheses indicates a button

to be pressed by the user. Buttons can be pressed in four ways:

1. Press a single button to select a function or operation.

2. Press a combination of buttons, one after the other.

3. Press and hold down a button, then press another button.

4. Press multiple buttons simultaneously.

For computer interface operation,

XXX An uppercase word without parentheses identifies a command

by name.

<XXX> Angle brackets around all uppercase letters mean press

the<XXX> key.

(xxx) When associated with a keyword, a lowercase word in

parentheses indicates an input required by the user.

1-6. Specifications

The following contains the specifications for the Fluke 45 Dual Display Multimeter. These specifications assume:

• A 1-year calibration cycle

• An operating temperature of 18 to 28ºC

• Relative humidity not exceeding 90% (non-condensing)

Accuracy is expressed as ±(percentage of reading + counts).

Reading Rates and Display Counts

Rate Readings per Second Full Range Display Counts

1-6

Slow

Medium

Fast

* Ohms full range will typically be 98,000 counts

2.5 5

99,999*

30,000

3,000

Response Times

Refer to Chapter 4 of the Users Manual for detailed information.

DC Voltage

Range

Introduction and Specifications

Specifications

Resolution Accuracy

Slow Medium Fast (6 months) (1 year)

300 mV 3 V 30 V 300 V 1000 V

100 mV 1000 mV 10 V 100 V 1000 V

1 µV 10 µV 100 µV 1 mV 10 mV

Input Impedance

10 MΩ in parallel with <100 pF

In the dual display mode, when the volts ac and volts dc functions are selected, the 10 M

Ω

divider.

Normal Mode Rejection Ratio

>80 dB at 50 or 60 Hz, slow and medium rates >54 dB for frequencies between 50-440 Hz, slow and medium rates >60 dB at 50 Hz, fast rate (Note: Fast rate has no filtering)

10 µV 100 µV 1 mV 10 mV 100 mV

100 µV 1 mV 10 mV 100 mV 1 V

0.02% + 2

0.02% + 6

Note

dc input divider is in parallel with the 1 MΩ ac

0.025%+2

0.025% +2

0.025%+2

0.025% +2

0.025%+2

0.025%+6

0.025% +6

0.025%+6

0.025% +6

0.025%+6

Maximum Allowable AC Voltage While Measuring DC Voltage

Peak Normal Mode Signal

Range Max Allowable Peak AC Voltage

300 mV 100 mV 20 V 15 V 15 V 3 V 1000 mV 20 V 15 V 15 V 30 V 10 V 1000 V 50 V 300 V 300 V 100 V 1000 V 50 V 300 V 1000 V 1000 V 1000 V 200 V 1000 V

* NMRR is the Normal Mode Rejection Ratio ** Normal Mode Rejection Ratio at 50 or 60 Hz ± 0.1%

NMRR* >80dB** NMRR >60 dB**

Common Mode Rejection Ratio

>90 dB at dc, 50 or 60 Hz, (1 kΩ unbalanced, medium and slow rates)

1-7

Service Manual

Maximum Functional Input

True Rms AC Voltage, AC-Coupled

1000 V dc or peak ac on any range

Range

Slow Medium Fast

300 mV - 10 µV 100 µV 3 V - 100 µV 1 mV 30 V - 1 mV 10 mV 300 V - 10 mV 100 mV 750 V - 100 mV 1 V

100 mV 1 µV - 1000 mV 10 µV - 10 V 100 µV - 100 V 1 mV - 750 V 10 mV - -

Resolution

Accuracy

Frequency Linear Accuracy dB Accuracy Power*

Max Input

at Upper

Freq

Slow Medium Fast Slow/Med Fast

20-50 Hz 1% + 100 1% + 10 7% + 2 0.15 0.72 2% + 10 750 V 50 Hz -10 kHz 0.2% + 100 0.2% + 10 0.5% +20.08 0.17 0.4% + 10 750 V

10 - 20 kHz 0.5% + 100 0.5% + 10 0.5% +20.11 0.17 1% + 10 750 V 20 - 50 kHz 2% + 200 2% + 20 2% + 3 0.29 0.34 4% + 20 400 V

50 - 100 kHz 5% + 500 5% + 50 5% + 6 0.70 0.78 10% + 50 200 V * Error in power mode will not exceed twice the linear accuracy specification

Accuracy specifications apply within the following limits, based on reading rate: Slow Reading Rate: Between 15,000 and 99,999 counts (full range)

Medium Reading Rate: Between 1,500 and 30,000 counts (full range) Fast Reading Rate: Between 150 and 3,000 counts (full range)

Decibel Resolution

Resolution

Slow & Medium Fast

0.01 dB 0.1 dB

1-8

Input Impedance

1 MΩ in parallel with <100 pF

Maximum Crest Factor

3.0

Common Mode Rejection Ratio

>60 dB at 50 or 60 Hz (1 kΩ unbalanced medium rate)

Maximum Input

750 V rms, 1000 V peak

2 x 10 1 x 10

Volt-Hertz product on any range, normal mode input

Volt-Hertz product on any range, common mode input

(AC + DC) Voltage Accuracy

Total Measurement Error will not exceed the sum of the separate ac and dc accuracy specifications, plus 1 display count. Refer to the table under "Maximum Allowable AC Voltage While Measuring DC Voltage or (AC + DC) Voltage" located on page 1-6.

Introduction and Specifications

Specifications

Note

When measuring AC + DC, (or any dual display combination of AC and DC) in the fast reading rate, the Fluke 45 may show significant reading errors. This results from a lack of filtering on the DC portion of the measurement for the fast reading rate. To avoid this problem, use only the "slow" and "medium" reading rates for AC + DC or AC and DC combinations.

Maximum Frequency of AC Voltage Input While Measur ing AC Current

When the meter makes ac current and ac voltage measurements using the dual display, the maximum frequency of the voltage input is limited to the maximum frequency of the current function. For example, if you are making an ac current measurement on the 10 A range, the maximum frequency of the voltage input must be less than 2 kHz.

DC Current

Range

Slow Medium Fast Accuracy

30 mA - 1 µA 10 µA 0.05% + 3 0.45 V 100 mA - 10 µA 100 µA 0.05% + 2 1.4 V 10 A - 1 mA 10 mA 0.2% + 5 0.25 V 10 mA 100 nA - - .05% + 15 0.14 V 100 mA 1 µA - - 0.05% + 5 1.4 V 10 A 100 µA - - 0.2% + 7 0.25 V

*Typical at full range

Resolution

Burden

Voltage*

1-9

Service Manual

Maximum Input

AC Current

mA 300 mA dc or ac rms. Protected with a 500 mA, 250 V, IEC 127-sheet I,

fastblow fuse and a 440 mA, 1000 V, fast blow fuse.

A 10 A dc ac rms continuous, or 20 A dc or ac rms for 30 seconds maximum.

protected with a 11 A, 1000 V, 17,000 A interrupt rating, fast blow fuse.

Note

Resistance between the COM binding post and the meter’s internal measuring circuits is approximately .003

Resolution

Range

10 mA 100 µA - - 0.14 V 30 mA - 1 µA 10 µA 0.45 V 100 mA 1 µA 10 µA 100 µA 1.4 V

Slow Medium Fast

Ω

Burden Voltage*

10 A 100 µA 1 mA 10 mA 0.25 V

* Typical at full range

Accuracy

Range Frequency

mA (To 100 mA) 20-50 Hz 2% + 100 2% + 10 7% + 2 mA (To 100 mA) 50 Hz - 10 kHz 0.5% + 100 0.5% + 10 0.8% + 2 mA (To 100 mA) 10 - 20 kHz 2% + 200 2% + 20 2% + 3 A (1-10 A) 20 - 50 Hz 2% + 100 2% + 10 7% + 2 A (1 - 10 A) 50 Hz - 2 kHz 1% + 100 1% + 10 1.3% + 2 A (0.5 to 1 A) 20 - 50 Hz 2% + 300 2% + 30 7% + 4 A (0.5 to 1 A) 50 Hz - 2 kHz 1% + 300 1% + 30 1.3% + 4

Slow Medium Fast

mA accuracy specifications apply within the following limits, based on reading rate: Slow Reading Rate: Between 15,000 and 99,999 counts (full range)

Medium Reading Rate: Between 1,500 and 30,000 counts (full range) Fast Reading Rate: Between 150 and 3,000 counts (full range)

1-10

Maximum Crest Factor

3.0

Maximum Input

mA 300 mA dc or ac rms. Protected with a 500 mA, 250 V, IEC 127-sheet I, fast

blow fuse and a 440 mA, 1000 V, fast blow fuse.

A 10 A dc or ac rms continuous, or 20 A dc or ac rms for 30 seconds maximum.

Protected with a 11 A, 1000 V, 17,000 A interrupt rating, fast blow fuse.

Resistance between the COM binding post and the meter’s internal measuring circuits is approximately .003

Ohms

Note

Ω

Introduction and Specifications

Specifications

Typical

Range Resolution Accuracy

Slow Medium Fast

300 Ω - 10 mΩ 100

mΩ

3 kΩ - 100 mΩ 1Ω 0.05% + 2 0.24 120 µA

30 kΩ -1 Ω 10 Ω 0.05% + 2 0.29 14 µA 300 kΩ - 10 Ω 100 Ω 0.05% + 2 0.29 1.5 µA 3 MΩ - 100 Ω 1 kΩ 0.06% + 2 0.3 150 µA 30 MΩ -1 kΩ 2% 0.25% + 3 2.25 320 µA 300

MΩ* 100 Ω 1 mΩ - - 0.05% + 8 + 0.02Ω 0.09 1 mA 1000 Ω 10 mΩ - - 0.05% + 8 + 0.02Ω 0.10 12 µA 10 kΩ 100 mΩ - - 0.05% + 8 0.11 14 µA 100 kΩ 1 Ω - - 0.05% + 8 0.11 1.5 µA 1000 kΩ 10 Ω - - 0.06% + 8 0.12 150 µA

- 100 kΩ 1 MΩ 2% 2.0 320 µA

0.05% + 2 + 0.02Ω 0.25 1 mA

Full Scale

Voltage

Max Current Through the

Unknown

10 MΩ 100 Ω - - 0.25% + 6 1.5 150 µA 100 MΩ 100 kΩ - - 2% + 2 2.75 320 µA

* Because of the method used to measure resistance, the 100 MΩ (slow) and 300 MΩ(medium and fast) ranges cannot measure below 3.2 MΩ and 20 MΩ, respectively. "UL" (underload) is shown on the display for resistances below these nominal points, and the computer interface outputs "+1E-9".

1-11

Service Manual

Open Circuit Voltage

Maximum Rated Input (Input Protection)

Diode Test/Continuity

Test Current

3.2 volts maximum on the 100 Ω, 300 Ω, 30 MΩ, 100 MΩ, and 300 MΩ ranges, 1.5 volts maximum on all other ranges.

1000 V dc or rms ac on all ranges

Maximum Reading Resolution

Slow 999.99 mV 10 µV

Medium 2.5 V 100 µV

Fast 2.5 V 1 mV

Approximately 0.7 mA when measuring a forward-biased junction.

Audible Tone

Continuous tone for continuity. Brief tone for normal forward biased diode or semiconductor junction.

Open Circuit Voltage

3.2 volts maximum

Continuity Capture Time

50 µs maximum, 10 µs typical

Maximum Rated Input (Input Protection)

1000 volts dc or rms ac

1-12

Frequency

5 Hz to > 1 MHz

Applicable Functions

Volts AC and Current AC

Resolution

Range

1000 Hz .01 Hz .1 Hz .05% + 2 10 kHz .1 Hz 1 Hz .05% +1 100 kHz 1 Hz 10 Hz .05% +1 1000 kHz 10 Hz 100 Hz .05% +1 1 MHz 100 Hz 1 kHz *

* For measurement of 1 MHz and lower, accuracy is .05% + 1. For measurement above 1 MHz, accuracy is not specified.

Slow & Medium Fast

Introduction and Specifications

Specifications

Accuracy

Sensitivity of AC Voltage

Frequency Level (Sine Wave)

5 Hz - 100 kHz 30 mV rms 100 kHz - 300 kHz 100 mV rms 300 kHz - 1 MHz 1 V rms Above 1 MHz Not Specified

Sensitivity Level of AC Current

Frequency Input Level

5 Hz - 20 kHz 100 mA >3 mA rms 45 Hz - 2 kHz 10 A >3 A rms

When the meter is set to measure frequency and there is no input signal (i.e., the input terminals are open), the meter may read approximately 25 kHz (rather than zero). This is due to internal capacitive pickup of the inverter power supply into the high-impedance, input circuitry. With source impedance of < 2 k stability of the frequency reading.

Note

Ω

, this pickup will not affect the accuracy or

1-13

Service Manual

Environmental

Warmup Time

Temperature Coefficient

Electromagnetic Compatibility

Operating Temperature

Storage Temperature

1 hour to rated specifications

<0.1 times the applicable accuracy specification per degree C for 0°C to 18°C and 28°C to 50°C

In an RF field of 1 V/m on all ranges and functions:

Total Accuracy = Specified Accuracy + .4% of range. Performance above 1 V/m is not specified.

0°C to 50°C

40°C to + 70°C

Elevated temperature storage of battery will accelerate battery self-discharge. Maximum storage time before battery must be recharged:

20 - 25°C 1000 days 50°C 180 days 70°C 40 days

Relative Humidity

To 90% at 0°C to 28°C , (non condensing) To 80% at 28°C to 35°C, To 70% at 35°C to 50°C except to 70% at 0°C to 50°C for the 1000 kΩ, 3 MΩ, 10 MΩ, 30 MΩ, 100 MΩ, and 300 MΩ ranges.

Altitude

Operating 0 to 10,000 feet Non-operating 0 to 40,000 feet

Vibration

3 G @ 55 Hz

Shock

Half sine 40G. Per Mil-T- 28800D, Class 3, Style E. Bench Handling. Per Mil-T-28800D, Class 3.

1-14

General

Common Mode Voltage

1000 V dc or rms ac maximum from any input to earth

Size

9.3 cm high, 21.6 cm wide, 28.6 cm deep

Weight

Net, 2.4 kg without battery; 3.2 kg with battery; Shipping, 4.0 kg without battery, 4.8 with battery.

Power

90 to 264 V ac (no switching required), 50 and 60 Hz. 15 VA maximum

Safety

Compliant with the following standards: ANSI/ISA S82.01-1994

CAN/CSA-C22.2 No. 1010. 1-92 EN61010.1:1993 to 1000 V Overvoltage Cat I, 600 V Overvoltage Cat II UL3111-1. See the following for an explanation of CATI and CATII categories.

Introduction and Specifications

Specifications

CAT I: OVERVOLTAGE (Installation) CATAGORY I, Pollution Degree 2 per IEC1010-1

refers to the level of Impulse Withstand Voltage protection provided. Equipment of OVERVOLTAGE CATEGORY I is equipment for connection to circuits in which measures are taken to limit the transient over voltages to an appropriate low level. Examples include protect electronic circuits.

CAT II: OVERVOLTAGE (Installation) CATAGORY II, Pollution Degree 2 per IEC1010-1

refers to the level of Impulse Withstand Voltage protection provided. Equipment of OVERVOLTAGE CATEGORY II is energy-consuming equipment to be supplied from the fixed installation. Examples include household, office, and laboratory appliances.

Electromagnetic Compatibility

Meets FCC Part 15 Subpart J. EN61326-1 (1998)

RS-232-C

Baud rates: 300, 600, 1200, 2400, 4800 and 9600

Odd, even or no parity One stop bit

1-15

Service Manual

Options

Battery (Option -01K)

Type

Operating Time

Recharge Time

IEEE-488 (Option -05K)

Capability Codes

8 V, Lead-Acid

8 hours (typical). N lights when less than 1/2 hour of battery operation remains. Meter still meets specifications.

16 hours (typical) with meter turned off and plugged into line power. Battery will not charge when meter is turned on.

SH1, AH1, T5, L4, SR1, RL1, PP0, DC1, DT1, E1, TE0, LE0 and C0 External Trigger Input VIH 1.35 V minimum VIL 1.25 V maximum

Input Threshold Hysteresis

0.6 V minimum

1-16

Chapter 2

Theory of Operation