FLUKE 27 电路图.pdf

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1、 27 Multimeter Service Manual For IEC 61010 CAT III Meters Only PN 690206 November 1998 1998 Fluke Corporation, All rights reserved. Printed in U.S.A. All product names are trademarks of their respective companies. RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱 好者资料库 i Table of Contents ChapterTitlePage

2、1Introduction and Specifications. 1-1 1-1.Using the Meter Safely . 1-3 1-2.Operating Instructions . 1-4 1-3.Specifications . 1-5 2Theory of Operation . 2-1 2-1.Introduction . 2-3 2-2.Functional Description . 2-3 2-3.Block Diagram Description . 2-4 2-4.Input Overload Protection . 2-4 2-5.Function Swi

3、tching Circuits . 2-4 2-6.Signal Conditioning Circuits . 2-4 2-7.Custom Analog IC (U1) . 2-4 2-8.Peripherals to U1 . 2-6 2-9.Microcomputer Control . 2-6 2-10.Display . 2-7 3Maintenance. 3-1 3-1.Introduction . 3-3 3-2.Service Information . 3-4 3-3.Operator Maintenance . 3-4 3-4.Battery Replacement .

4、3-5 3-5.Fuse Test . 3-6 3-6.Fuse Replacement . 3-6 3-7.General Maintenance Information . 3-7 3-8.Handling Precautions for Static-Sensitive Devices . 3-7 3-9.Disassembly . 3-7 3-10.Reassembly . 3-10 3-11.Cleaning . 3-12 3-12.Performance Tests . 3-12 3-13.Display Test . 3-12 3-14.Voltage Functions Per

5、formance Verification . 3-13 3-15.AC and DC Current Performance Verification . 3-13 3-16.Ohms Function Performance Verification . 3-14 RadioFans.CN 收音机爱 好者资料库 27 Service Manual ii 3-17.Diode Test Performance Verification . 3-15 3-18.Calibration Adjustment . 3-15 3-19.Calibration Preparation . 3-15 3

6、-20.DC Voltage Connection . 3-16 3-21.AC Voltage Calibration . 3-16 3-22.Troubleshooting . 3-17 3-23.Power-Up Self Test . 3-17 3-24.Overall System Check . 3-17 3-25.DC Voltage Signal Tracing . 3-18 3-26.Fault Diagnosis Guide . 3-19 4List of Replaceable Parts. 4-1 4-1.Introduction . 4-3 4-2.How to Ob

7、tain Parts . 4-3 4-3.Manual Status Information . 4-3 4-4.Newer Instruments . 4-4 4-5.Service Centers . 4-4 4-6.Parts Lists . 4-5 5Schematic Diagrams . 5-1 iii List of Tables TableTitlePage 1-1.Specifications. 1-5 3-1.Recommended Test Equipment . 3-3 3-2.Replacement Fuses. 3-6 3-3.Ohm Function Perfor

8、mance Test. 3-15 3-4.Fault Diagnosis Guide. 3-19 4-1.Final Assembly . 4-6 4-2.A1 Main PCA . 4-8 4-3.A2 Digital PCA. 4-11 27 Service Manual iv v List of Figures FigureTitlePage 3-1.Battery and Fuse Replacement. 3-5 3-2.Disassembly. 3-8 3-3.Calibration Adjustment Locations . 3-16 4-1.Final Assembly .

9、4-7 4-2.A1 Main PCA . 4-10 4-3.A2 Digital PCA. 4-11 5-1.A1 Main PCA and A2 Digital PCA. 5-3 27 Service Manual vi 1-1 Chapter 1 Introduction and Specifications TitlePage 1-1.Using the Meter Safely. 1-3 1-2.Operating Instructions. 1-4 1-3.Specifications. 1-5 27 Service Manual 1-2 Introduction and Spec

10、ifications Using the Meter Safely1 1-3 1-1. Using the Meter Safely Use the meter as described in this manual. Otherwise the safety features provided by the meter might be impaired. A Warning identifies conditions and actions that pose hazards to the user; a Caution identifies conditions and actions

11、that might damage the meter. Read First: Safety Information. Read First: Safety Information This meter complies with EN 61010-1:1993, ANSI/ISA S82.01- 1994 and CAN/CSA C22.2 No. 1010.1-92 Overvoltage Category III. Use the meter only as specified in the Users Manual, otherwise the protection provided

12、 by the meter may be impaired. Warning To avoid possible electric shock or personal injury: Do not use the meter if it is damaged. Before use, inspect the case for cracks or missing plastic. Pay particular attention to the insulation surrounding the connectors. Inspect the test leads for damaged ins

13、ulation or exposed metal. Check test lead continuity. Replace damaged leads. Do not use the meter if it operates abnormally. Protection may be impaired. When in doubt, have the meter serviced. Do not operate the meter around explosive gas, vapor or dust. Do not apply more than the rated voltage, as

14、marked on the meter, between terminals or between any terminal and earth ground. Before each use, verify the meters operation by measuring a known voltage. When servicing the meter, use only specified replacement parts. Use caution when working above 30 V ac rms, 42 V ac peak, or 60 V dc. Such volta

15、ges pose a shock hazard. Keep your fingers behind the finger guards on the probe when making measurements. Connect the common test lead before connecting the live test lead. Disconnect the live test lead first. Remove test leads from the meter before opening the battery door. Make sure the battery d

16、oor is closed and latched before operating the meter. Use only a single 9 V battery, properly installed in the meter case, to power the meter. Follow all equipment safety procedures. 27 Service Manual 1-4 Before measuring current, check the meters fuses (see “How to Test the Fuse”). Never touch the

17、probe to a voltage source when the test leads are plugged into the 10 A or 40 mA input jacks. To avoid false readings, which could lead to possible electric shock or personal injury, replace the meters battery as soon as the low battery indicator () appears. Avoid working alone. Caution To avoid pos

18、sible damage to the meter or to equipment under test: Disconnect the power to the circuit under test and discharge all high voltage capacitors before testing resistance, continuity or diodes. Use the proper function and range for your measurement applications. When measuring current, turn off circui

19、t power before connecting the meter in the circuit. Remember to place the meter in series with the current. This manual presents service information for the Fluke 27 Multimeters. Included are a theory of operation, general maintenance procedures, performance tests, calibration procedures, troublesho

20、oting information, a list of replaceable parts, and a schematic diagram. 1-2. Operating Instructions For operating instructions, refer to the Users Manual provided with the instrument at time of purchase. Introduction and Specifications Specifications1 1-5 1-3. Specifications Instrument specificatio

21、ns are presented in Table 1-1. Table 1-1. Specifications FunctionRangeResolutionAccuracy 3.200 V 32.00 V 320.0 V 1000 V 0.001 V 0.01 V 0.1 V 1 V (0.1%+1) (0.1%+1) (0.1%+1) (0.1%+1) 320.0 mV0.1 mV(0.1%+1) 320.00 0.1 (0.3%+3)* 3.200 k0.001 k(0.2%+1) 32.00 k0.01 k(0.2%+1) (nS) 320.0 k0.1 k(0.2%+1) 3.20

22、0 M0.001 M(0.2%+1) 32.00 M 32.00 nS 0.01 M 0.01 nS (1%+1) (0.2%+10) 2.080 V0.001 V(1%+1) typical 40 Hz-2 kHz2 kHz -10 kHz10 kHz -30 kHz 3.200 V0.001 V(0.5%+3)(2%+3)(4%+ 10) 32.00 V0.01 V(0.5%+3)(2%+3)(4%+ 10) 320.0 V0.1 V(0.5%+3)(2%+3)(4%+ 10) 1000 V1 V(1%+3)(3%+3)Not Specified 320.0 mV0.1 mV(0.5% +

23、3)(2%+3)(4%+10) * When using the REL function to compensate for offsets. FunctionRangeResolutionAccuracyTypical Burden Voltage m/A 32.00 mA 320.0 mA 10.00 A 0.01 mA 0.1 mA 0.01 A (0.75%+2) (0.75%+2) (0.75%+2) 5.6 mV/mA 5.6 mV/mA 50 mV/A A 320.0 A 3200 A 0.1 A 1 A (0.75%+2) (0.75%+2) 0.5 mV/A 0.5 mV/

24、A mA/A 40-1000 Hz 32.00 mA 320.0 mA 10.00 A 0.01 mA 0.1 mA 0.01 A (1.5%+2) (1.5%+2) (1.5%+2) 5.6 mV/mA 5.6 mV/mA 50 mV/A A 40-1000 Hz 320.0 A 3200 A 0.1 A 1 A (1.5%+2) (1.5%+2) 0.5 mV/A 0.5 mV/A 27 Service Manual 1-6 Table 1-1. Specifications (cont) FunctionOverload Protection* Input Impedance (nomi

25、nal) Common Mode Rejection Ratio (1 k unbalance) Normal Mode Rejection 1000 V rms10 M in / with 120 dB at dc, 50 Hz, or 60 Hz60 dB at 50 Hz or 60 Hz 1000 V rms10 M in / with 120 dB at dc, 50 Hz, or 60 Hz60 dB at 50 Hz or 60 Hz 1000 V rms 10 M in / with 60 dB, dc to 60 Hz 1000 V rms 10 M in / with 60

26、 dB, dc to 60 Hz 1000 V rmsOpen Circuit Test Voltage Full Scale Voltage Up to 3.2 M32 M or nS 2.8 V dc420 mV dc28C) Relative Humidity0% to 95% (0C to 35C) 0% to 70% (35C to 55C) Altitude2000 meters Battery Type9 V, NEDA 1604 or 6F22 or 006P Battery Life1000 hrs typical Shock, Vibration and Water Res

27、istance Per MIL-T-28800 for a Style A, Class 2 Instrument Size (HxWxL)2.2 in x 3.75 in x 8 in (5.6 cm x 9.5 cm x 20.3 cm) Weight1.6 pounds (0.75 kg) SafetyComplies with ANSI/ISA S82.01-1994, CAN/CSA 22.2 NO. 1010.1:1992 to 1000 V Overvoltage Category III. UL License pending to UL3111-1. TUV License

28、pending to EN61010-1. 2-1 Chapter 2 Theory of Operation TitlePage 2-1.Introduction . 2-3 2-2.Functional Description. 2-3 2-3.Block Diagram Description. 2-4 2-4.Input Overload Protection . 2-4 2-5.Function Switching Circuits. 2-4 2-6.Signal Conditioning Circuits. 2-4 2-7.Custom Analog IC (U1) . 2-4 2

29、-8.Peripherals to U1. 2-6 2-9.Microcomputer Control. 2-6 2-10.Display . 2-7 27 Service Manual 2-2 Theory of Operation Introduction2 2-3 2-1. Introduction This chapter describes how the Fluke 27 works. First, a functional description presents an overview of operation. This is followed by a block diag

30、ram description, which describes the major circuit functions in more detail. For reference, a detailed schematic diagram is included in Chapter 5. 2-2. Functional Description A block diagram of the Fluke 27 circuitry is shown in Figure 2-1. As this figure shows, the instrument is composed of two major functional sections: