KEI29662B(Model172A,173A) 电路图.pdf

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1、Models 172A, 173A Instruction Manual Contains Operating and Servicing Information for the Models 172A, 173A Digital Multimeter Publication Date: August 1978 Keithley Instruments, Inc. Instrument Division Cleveland, Ohio, U.S.A. Document Number: 29662, Rev. B RadioFans.CN 收音机爱 好者资料库 RadioFans.CN 收音机爱

2、 好者资料库 INSTRUCTION MANUAL Digltal Multlmster Models 172A. 173A INSTRUCTION MANUAL Digital Multimeter MODELS 172A/173A COPYRIGHT 1978, KEITHLEY INSTRUMENTS, INC. PRINTEU APRIL, 1981, CLEVELAND, OHIO, U.S.A. DOCUMENT NO. 29662, REV. B RadioFans.CN 收音机爱 好者资料库 CONTENTS INSTRUCTION MANUAL DigItal Mulllmr

3、tw Mod.1 17ZA. 173A ,ction Page INTENTS . .LuSTRATIoNs . GENERAL INFORMATION . I-l l-l. INTROOUCTION. . 1-I l-2. FEATURES . l-1 l-3. WARRANTY INFORMATION. . l-l I-4. CHANGE NOTICE . I-I l-5. OPTIONAL MODEL 1728 RECHARGEABLE BATTERY PACK . l-1 1-6. OPTIONAL MODEL 1722 DIGITAL INTERFACE . I-I 1-7. OPT

4、IONAL MODEL 1723 IEEE STANDARD 488 BUS INTERFACE . I-1 IECIFiCATIONS. . I- INITIAL PREPARATION . 2-l 2-1. GENERAL . .2-l 2-2. INSPECTION. . 2-l 2-3. PREPARATION FOR USE . 2-I OPERATING INSTRUCTIONS. . 3-l 3-l. GENERAL . .3- 1 3-2. HOW TO SELECT POWER . 3-l ;I; HOW TO SELECT FUNCTION. . 3-2 3-5: HOW

5、TO SELECT RANGE . 3-3 HOW TO MEASURE VOLTAGE. . 3-4 3-6. HOW TO MEASURE CURRENT. (MODEL 172A ONLY) . 3-5 3-7. HOW TO MEASURE CURRENT. (MODEL 173A ONLY) . 3-6 3-8. HOW TO MEASURE RESISTANCE . 3-7 3-9. FURTHER MEASUREMENT CONSIDERATIONS. . 3-8 3-10. HOW TO USE MODEL 172A/l73A OFF-GROUND . 3-11 3-11. H

6、OW TO USE OPTIONAL PROBES AND SHUNTS . 3-12 3-12. HOW TO USE THE MODEL 1722 DIGITAL INTERFACE . 3-13 3-13. COMMENTS RELATIVE TO THE MODEL 172A/l73A SPECIFICATIONS . 3-25 3-14. MODEL 1728 OPERATING Tips . ACCESSORIES. . . . if:;5 4-1. GENERAL.4- I 4-2. POWER OPTIONS . 4-l 4-3. ISOLATED DIGITAL OUTPUT

7、 . 4-1 4-4. RACK MOUNTING . 4-i 4-5. PROBE AND SHUNTS. . 4-4 4-6. CABLES AND CONNECTORS . 4-5 4-7. MISCELLANEOUS . 4-5 THEORY OF OPERATION . 5-l . 5-l. GENERAL.5- I 5-2. OVERALL OPERATION . 5-l 5-3. INPUT SIGNAL CONDITIONING . 5-l 5-4. A/O CONVERTER AND DIGITAL CIRCUITS (SCHEMATIC 29145E, SHEET 2).

8、. 5-15 5-5. DISPLAY BOARD, SCHEMATIC 274040 . S-21 5-6. POWER SUPPLY, SCHEMATIC 29145E. . 5-21 MODEL 1728 RECHARGEABLE BATTERY PACK, SCHEMATIC 26758C. . 5-23 MODEL 1722 DIGITAL INTERFACE. . 5-25 I ii INSTRUCTION MANUAL Digital MultImeter Models 172A. 173A CONTENTS (CONS) iect ion Page ;. MAINTENANCE

9、. 6-i. GENERAL . ;I; 6-2. REQUIRED TEST EQUIPMENT. . 6-l PERFORMANCE VERIFICATION . 6-l CALIBRATION REQUIREMENTS . 6-7 6-5. PREPARATION FOR CALIBRATION. . 6-8 6-6. CALIBRATION PROCEDURE. . 6-Y 6-7. TROUBLESHOOTING AND REPAIR . 6-15 6-8. FUSE REPLACEMENT . 6-21/Z 7. REPLACEABLE PARTS. . 7-1 7-l. GENE

10、RAL.7- 1 7-2. ORDERING INFORMATION . 7-I 7-3. FACTORY SERVICE. . 7-l 7-4. REPLACEABLE PARTS LIST . 7-l CROSS REFERENCE OF MANUFACTURERS . 7-2 COVERS AND PANELS. . 7-2 COMPONENT DESIGNATIONS FOR -446. . 7-2 7-a. SCHEMATICS . 7-2 7-Y. COMPONENT LAYOUTS. . 7-2 7-10. SPARE PARTS KIT. . 7-5 iii INSTRUCTI

11、ON MANUAL Digital MuItlm*ter Mod: :i ;:; 3-7 3-a 3-9 3-10 3-11 3-12 4-l 4-2 5-l :; 5-4 5-5 5-6 5-J 5-a 5-9 5-10 5-11 5-12 ;:; :I; :g 6-l 6-2 J-1 Model l73A Front Panel . 1-3 Bottom View Showing Line Cord. . l-4 Tilt Bail Positions. . l-5 Dimensional Data . 1-6 Rear Panel Showing Current Fuse. . 2-2

12、Model 1728 Rechargeable Battery Pack . 2-4 Installation of Battery Pack . 2-5 Front Panel Pushbutton Selection . 3-3 Typical Model 172A Current Display (DCnA). . 3-5 Typical Model l73A Current Display (ACmA). . 3-6 Typical 2 WIRE Resistance Measurement. . 3-7 Typical 4 WIRE Resistance Measurement. .

13、 3-V Semiconductor Diode and Transistor Testing . 3-10 Use of Multimeter Off Ground . 3-11 Model 1722 Digital Output Interface. . 3-14 Installation of Model I722 . 3-15 Connector Pin Identification For 1006 and PllOl . 3-17 Card-Edge Connectors (Model 1727 Cable Set). . 3-17 Location of Jumpers and

14、Pull-ups on Model 1722 . 3-18 Model 1010 Single Rack Mounting Kit. . 4-2 Model 1017 Dual Rack Mounting Kit . 4-4 Overall Block Diagram of Model 172A/l73A . 5-2 Simplified Block Diagram of Signal Conditioning Circuits . 5-2 Simplified Schematic of DC Attenuator. . 5-6 Simplified Schematic of AC/DC Co

15、nverter. . 5-7 Simplified Schematic of 173A I/V Converter 5-8 Simplified Schematic of Model l72A I/V Converter 5-8 Simplified Ohms Converter, Two-Wire Ohms Configuration . 5-10 Four-Wire Ohms Measuring Technique . 5-10 Simplified Schematic of Clamp. . 5-12 Simplified Schematic of Active Filter. . .,

16、 . 5-12 Simplified Block Diagram of A/D Converter. . 5-14 A/D Converter System Timing . 5-15 Simplified Schematic of A/D Buffer 5-16 Simplified Schematic of the A/D Converter, . 5-17 Simplified Schematic of 669 kHz Oscillator . 5-19 Simplified Schematic of Reference Supply 5-20 Digital Display Multi

17、plex Scheme . 5-22 Model 1722 Block Diagram . 5-24 Location of Calibration fidjustments. . 6-10 Location of Connectors and Test Points . 6-14 TOD and Bottom Cover Assembly . 7-3 iv INSTRUCTION MANUAL Digital Multimeter Models 172A. 173A GENERAL INFORMATION - SECTION 1. GENERAL INFORMATION. I-l. INTR

18、OOUCTION. Thk Models, l72A and 173A Digital Multimeters are wide-range, general- purpose measuring instruments, capable of measuring ac/dc voltage, ac/dc current and resistance. (See Table 1-I for Specifications, Page l-2). l-2. FEATURES. a. Automatic Ranging and Polarity. b. Manual Range Selection

19、and Range Hold. c. HI and LO Ohms Capability. d. Line Operation. e. Optional Battery Operation, Model 1728. f. Floating Capability to +14OOV peak. 9. Optional Isolated Digital Interface, Model 1722/1723. 1-3. WARRANTY INFORMATION. The warranty is stated on the inside Front cover of the manual. If th

20、ere is a need for service, contact your Keithley representative or author- ized repair facility as given in our catalog. l-4. CHANGE NOTICE. Improvements or changes to the instrument not incorporated into the manual will be explained on a change notice sheet attached to the inside back cover of the

21、manual. l-5. OPTIONAL MODEL 1728 RECHARGEABLE BATTERY PACK. The Model 1728 is an accessory battery pack which enables either line or battery operation. The Model 1728 has built- in recharging circuitry. The Model 1728 is field-installed on the Model 172A/l73A chasis. l-6. OPTIONAL MODEL 1722 DIGITAL

22、 INTERFACE. The Model 1722 is a field-installable digital output option. It provides isolated open-collector ECD outputs and control lines. 1-7. OPTIONAL MOOEL 1723 IEEE STANDARD 488 BUS INTERFACE. The Model 1723 is a field- installable digital interface option that provides logic and control functi

23、ons necessary to make the Model 172A or l73A bus compatible in accordance with the IEEE Standard 48B- 1975. Refer to the Instruction Manual for Model 1723 for operation and service instruction! for this option. IMPORTANT The A Symbol can be found in various places in this Instruction Manual. Care- f

24、ully read the associated CAUTION statements with regard to proper use and handling of the instrument. Damage to the instrument may occur if these precautions are ignored. The symbol can be found in various places in this Instruction Manual. This symbol indicates those areas on the instrument which a

25、re potential shock hazards. Carefully read the associated WARNING statements with regard to proper use and handling of the instrument. Serious personal injury may result if these pre- cautions are ignored. l-l GENERAL INFORMATION INSTRUCTION MANUAL Digital Multimet*r TABLE 1-1. Models 112A,. 113A SP

26、ECIFICATIONS INSTRUCTION MANUAL Digital Multimeter Models 172A. 173A GENERAL INFORMATION FUNCTION AND UNITS DISPLAY (mV) I INPUT HI AND LO. UPPER PAIR - FIGURE l-1. Model 173A Front Panel. 1-3 IN= I nub I I”N MANUAL Digital Multimeter Models 172A. 173A r TEST POINT “A” FIGURE l-2. Bottom View Showin

27、g Line Cord. 1-4 INSTRUCTION MANUAL GENERAL INFORMATION Digital Multimster Models 172A. 173A NORMAL BENCH POSITION c I -I I LEVEL POSITION - TILTBAIL AT FRONT HANGING POSITION 4% 45” POSITION -I y LEVEL POSITION - TILTBAIL AT REAR FIGURE l-3. Tilt Bail Positions. GENERAL INFORMATION INSTRUCTION MANU

28、AL Digital Multimeter Models 172A. i73A ht 5,-l ht 5,-l OMENSIONS IN MILLIMETERS (INCHES) OMENSIONS IN MILLIMETERS (INCHES) FIGURE l-4. Dimensional Data 1-6 INSTRUCTION MANUAL Digital Multimeter Models 172A. 173A INITIAL PREPARATION SECTION 2. INITIAL PREPARATION. 2-i. GENERAL. This section provides

29、 information needed for incoming inspection and preparation for use. 2-2. INSPECTION. The Model 172A/173A was carefully inspected both mechanically and electrically before shipment. Upon receiving the instrument, clieck for any obvious dam- ages which may have occurred during transit. Report any dam

30、ages to the shipping agent. To verify the electrical specifications, follow the procedures given in Section 6. 2-3. PREPARATION FOR USE. The Model 172A/l73A is shipped ready-to-use. The instrument can be powered from line voltage or from rechargeable nickel-cadmium batteries (when the optional Model

31、 1728 Rechargeable Battery Pack is installed). a. Line Power. The Model 172A/l73A has an attached three-wire line cord which mates with third-wire grounded receptacles (NEHA 5-l5P). The permanently installed line cord is stored by wrapping the cord around the base of the instrument as shown in Figur

32、e 4. CAUTION A This instrument has an internal line power selector switch that must be set to 234V position for operation above 125 volts rms, 50-60 Hz. I. How to set the Internal Line Voltage Switch (S6Ol). The Model 172A/l73A has a two position slide switch located on the main circuit board. For o

33、peration above 125 volts, the switch setting and fuse must be changed. The top cover must be removed to gain access to the circuit board as described in MAINTENANCE section. WARNING t Disconnect the line cord before removing the top cover of the instrument. Line voltage is present at various points

34、on the circuit board and represents a SHOCK HAZARD. NOTE Optional line voltage range is available when wiring modifications are made to transformer T60l as shown on schematic 29145E. TABLE 2-l. Summary of Standard and Optional Line Voltages. - I I 1 / Standard I opt1 -nab 105 to 125 V rms 90 - 105 V

35、 rms - Transformer wiring 210 to 250 V rms must be modified. 2-l INITIAL PREPARATION INS: I ItUG I ION MANUAL oigwd MYlllnle*er Models 172A. 173A FUSE F501 FIGURE 2-l. Rear Panel Showing Current Fuse. 2-2 INSTRUCTION MANUAL Digital Multimeter Models 172A. 173A INITIAL PREPARATION 2. Line Fuse Requir

36、ement. The Model 172A/l73A uses a single line fuse to protect the line-operated power supply. The fuse is a 3 AB or 3 AG, slow-blow type. Rep lace with I/4 ampere for II7 volts operation or l/8 ampere for 234 volrs. IMPORTANT A Replace fuse with correct rating, otherwise, damage to the instrument co

37、uld result. 3. How to Replace the Line Fuse. The fuse is installed on the main circuit board as shown in Figure 6-2 (Page b-14). The top cover must be removed to gain access to the circuit board as described in Section 6. FU-20 (1/8A) for 234V. Use Keithiey FU-I7 (l/4A) for II7 V; WARN I NG t Discon

38、nect the line cord before removing the top cover of the instrument. Line voltage is present at various points on the circuit board and represent a SHOCK HAZARD. CAUT I ON A The fuse installed on the rear panel of the Model 172A/l73A is used only for current range protection. This fuse is not a line

39、voltage protection fuse. - b. Battery Power. To operate the Model 172A/l73A from batteries, the Model 1723 Rechargeable Battery Pack must be installed. The /*ode1 1728 can be either field or factory-installed (at the time the Model 172A/l73A is purchased). NOTE The Model 1728 Rechargeable Battery Pa

40、ck can be installed by the user within me Model 172A/l73A at any time. However, if the Model I722 Digital Output is already installed, the Model 1728 cannot be used simultaneously. I . How to Install the Model 1728 Rechargeable Battery Pack. The batteries furnisnec with the Model 1728 are already in

41、stalled in the battery pack. The battery pack in- cludes 7 rechargeable “C” cells (l.2V, 2 AMP Hr) and two 19.2 volt packs (sixteen I.?/- cells per pack). See Figure 2-3. =) Check the fuses on the Battery Pack. Three fuses are used. All are I ampere, 3AB or 3 AG, Slo-Blo types, Keithley Part Ho. FU-IO. b) Check for proper installation of batteries in the Battery Pa