FLUKE 123 电路图.pdf

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1、4822 872 05375 August 1997, Rev. 3, 01/00 1997 Fluke Corporation. All rights reserved. Printed in the Netherlands All product names are trademarks of their respective companies. 123 Industrial ScopeMeter Service Manual RadioFans.CN 收音机爱 好者资料库 SERVICE CENTERS To locate an authorized service center, v

2、isit us on the World Wide Web: or call Fluke using any of the phone numbers listed below: +1-888-993-5853 in U.S.A. and Canada +31-402-678-200 in Europe +1-425-356-5500 from other countries RadioFans.CN 收音机爱 好者资料库 Table of Contents ChapterTitlePage 1Safety Instructions. 1-1 1.1 Introduction. 1-3 1.2

3、 Safety Precautions. 1-3 1.3 Caution and Warning Statements. 1-3 1.4 Symbols. 1-3 1.5 Impaired Safety. 1-4 1.6 General Safety Information. 1-4 2Characteristics . 2-1 2.1 Introduction. 2-3 2.2 Dual Input Oscilloscope. 2-3 2.2.1 Vertical . 2-3 2.2.2 Horizontal. 2-4 2.2.3 Trigger . 2-4 2.2.4 Advanced S

4、cope Functions. 2-5 2.3 Dual Input Meter. 2-5 2.3.1 Input A and Input B. 2-5 2.3.2 Input A. 2-8 2.3.3 Advanced Meter Functions. 2-8 2.4 Miscellaneous . 2-9 2.5 Environmental. 2-10 2.6 Service and Maintenance. 2-11 2.7 Safety . 2-11 2.8 EMC Immunity . 2-12 3Circuit Descriptions . 3-1 3.1 Introduction

5、. 3-3 3.2 Block Diagram. 3-3 3.2.1 Channel A, Channel B Measurement Circuits. 3-4 3.2.2 Trigger Circuit. 3-4 3.2.3 Digital Circuit. 3-5 3.2.4 Power Circuit. 3-6 3.2.5 Start-up Sequence, Operating Modes. 3-7 RadioFans.CN 收音机爱 好者资料库 123 Service Manual 3.3 Detailed Circuit Descriptions. 3-9 3.3.1 Power

6、 Circuit. 3-9 3.3.2 Channel A - Channel B Measurement Circuits . 3-15 3.3.3 Trigger Circuit. 3-20 3.3.4 Digital Circuit. 3-25 4Performance Verification. 4-1 4.1 Introduction. 4-3 4.2 Equipment Required For Verification . 4-3 4.3 How To Verify. 4-3 4.4 Display and Backlight Test. 4-4 4.5 Input A and

7、Input B Tests. 4-5 4.5.1 Input A and B Base Line Jump Test. 4-6 4.5.2 Input A Trigger Sensitivity Test. 4-7 4.5.3 Input A Frequency Response Upper Transition Point Test. 4-8 4.5.4 Input A Frequency Measurement Accuracy Test. 4-8 4.5.5 Input B Frequency Measurement Accuracy Test . 4-9 4.5.6 Input B F

8、requency Response Upper Transition Point Test. 4-10 4.5.7 Input B Trigger Sensitivity Test. 4-10 4.5.8 Input A and B Trigger Level and Trigger Slope Test. 4-11 4.5.9 Input A and B DC Voltage Accuracy Test. 4-14 4.5.10 Input A and B AC Voltage Accuracy Test. 4-15 4.5.11 Input A and B AC Input Couplin

9、g Test. 4-16 4.5.12 Input A and B Volts Peak Measurements Test. 4-17 4.5.13 Input A and B Phase Measurements Test. 4-18 4.5.14 Input A and B High Voltage AC/DC Accuracy Test. 4-19 4.5.15 Resistance Measurements Test. 4-20 4.5.16 Continuity Function Test. 4-21 4.5.17 Diode Test Function Test . 4-22 4

10、.5.18 Capacitance Measurements Test . 4-22 4.5.19 Video Trigger Test. 4-23 5Calibration Adjustment. 5-1 5.1 General. 5-3 5.1.1 Introduction. 5-3 5.1.2 Calibration number and date. 5-3 5.1.3 General Instructions. 5-3 5.2 Equipment Required For Calibration. 5-4 5.3 Starting Calibration Adjustment. 5-4

11、 5.4 Contrast Calibration Adjustment . 5-6 5.5 Warming Up so only one of these functions needs to be verified. 4.2 Equipment Required For Verification The primary source instrument used in the verification procedures is the Fluke 5500A. If a 5500A is not available, you can substitute another calibra

12、tor as long as it meets the minimum test requirements. Fluke 5500A Multi Product Calibrator, including 5500A-SC Oscilloscope Calibration Option. Stackable Test Leads (4x), supplied with the 5500A. 50 Coax Cables (2x), Fluke PM9091 (1.5m) or PM9092 (0.5m). 50 feed through terminations (2x), Fluke PM9

13、585. Fluke BB120 Shielded Banana to Female BNC adapters (2x), supplied with the Fluke 123. Dual Banana Plug to Female BNC Adapter (1x), Fluke PM9081/001. Dual Banana Jack to Male BNC Adapter (1x), Fluke PM9082/001. TV Signal Generator, Philips PM5418. 75 Coax cable (1x), Fluke PM9075. 75 Feed throug

14、h termination (1x), ITT-Pomona model 4119-75. PM9093/001 Male BNC to Dual Female BNC Adapter 4.3 How To Verify Verification procedures for the display function and measure functions follow. For each procedure the test requirements are listed. If the result of the test does not meet the requirements,

15、 the test tool should be recalibrated or repaired if necessary. 123 Service Manual 4-4 Follow these general instructions for all tests: For all tests, power the test tool with the PM8907 power adapter. The battery pack must be installed. Allow the 5500A to satisfy its specified warm-up period. For e

16、ach test point , wait for the 5500A to settle. Allow the test tool a minimum of 20 minutes to warm up. 4.4 Display and Backlight Test Proceed as follows to test the display and the backlight: 1. Press TO TURN THE Test tool on. 2. Press and verify that the backlight is dimmed. Then select maximum bac

17、klight brightness again. 3. Remove the adapter power, and verify that the backlight is dimmed. 4. Apply the adapter power and verify that the backlight brightness is set to maximum. 5. Press and hold . 6. Press and release . 7. Release . The test tool shows the calibration menu in the bottom of the

18、display. Do not press now! If you did, turn the test tool off and on, and start at 5. 8. Press (PREV) three times. The test tool shows Contrast (CL 0100):MANUAL 9. Press (CAL) . The test tool shows a dark display; the test pattern as shown in Figure 4-1 may not be visible or hardly visible. Observe

19、the display closely, and verify that no light pixels are shown. Figure 4-1. Display Pixel Test Pattern 11. Press . The test pattern is removed; the test tool shows Contrast (CL 0110):MANUAL Performance Verification 4.5 Input A and Input B Tests4 4-5 12. Press (CAL) . The test tool shows the display

20、test pattern shown in Figure 4-1, at default contrast. Observe the test pattern closely, and verify that the no pixels with abnormal contrast are present in the display pattern squares. Also verify that the contrast of the upper left and upper right square of the test pattern are equal. 13. Press .

21、The test pattern is removed; the test tool shows Contrast (CL 0120):MANUAL 14. Press (CAL) . The test tool shows a light display; the test pattern as shown in Figure 4-1 may not be visible or hardly visible. Observe the display closely, and verify that no dark pixels are shown. 15. Turn the test too

22、l OFF and ON to exit the calibration menu and to return to the normal operating mode. 4.5 Input A and Input B Tests Before performing the Input A and Input B tests, the test tool must be set in a defined state, by performing a RESET. Proceed as follows to reset the test tool: Press to turn the test

23、tool off. Press and hold . Press and release to turn the test tool on. Wait until the test tool has beeped twice, and then release . When the test tool has beeped twice, the RESET was successful. For most tests, you must turn Input B on. Input A is always on. Proceed as follows to turn Input B on: P

24、ress to open the Meter B menu. Using select INPUT B: ON . Press to confirm the selection; the mark changes to I . The active setting from the next item group will be highlighted (for example I VAC ), and maintained after leaving the menu. Press to exit the menu. During verification you must open men

25、us, and to choose items from the menu. Proceed as follows to make choices in a menu (see Figure 4.2): Open the menu, for example press . Press to highlight the item to be selected in a menu. Press to confirm the selection and to jump to the next item group (if present). Item groups in a menu are sep

26、arated by a vertical line. After pressing in the last menu item group, the menu is closed. 123 Service Manual 4-6 ST7968.CGM Figure 4-2. Menu item selection If an item is selected, it is marked by I. Not selected items are marked by . If a selected item is highlighted, an then is pressed, the item r

27、emains selected. You can also navigate through the menu using . To conform the highlighted item you must press . 4.5.1 Input A and B Base Line Jump Test Proceed as follows to check the Input A and Input B base line jump: 1. Short circuit the Input A and the Input B shielded banana sockets of the tes

28、t tool. Use the BB120 banana to BNC adapter, and a 50 (or lower) BNC termination. 2. Select the following test tool setup: Turn Input B on (if not already on). Press to select auto ranging (AUTO in top of display). ( toggles between AUTO and MANUAL ranging). Press to open the SCOPE INPUTS menu. Pres

29、s to open the SCOPE OPTIONS menu, and choose : SCOPE MODE: I NORMAL | WAVEFORM MODE: I SMOOTH 3. Using toggle the time base between 10 ms/div and 5 ms/div. (the time base ranging is set to manual now, the input sensitivity is still automatic; no indication AUTO or MANUAL is displayed). After changin

30、g the time base wait some seconds until the trace has settled. Observe the Input A trace, and check to see if it returns to the same position after changing the time base. The allowed difference is 0.04 division (= 1 pixel). Observe the Input B trace for the same conditions. 4. Using toggle the time

31、 base between 1 s/div and 500 ns/div. After changing the time base wait some seconds until the trace has settled. Observe the Input A trace, and check to see if it is set to the same position after changing the time base. The allowed difference is 0.04 division (= 1 pixel). Observe the Input B trace

32、 for the same conditions. Performance Verification 4.5 Input A and Input B Tests4 4-7 5. Using set the time base to 10 ms/div. 6. Using toggle the sensitivity of Input A between 5 and 10 mV/div. After changing the sensitivity wait some seconds until the trace has settled. Observe the Input A trace,

33、and check to see if it is set to the same position after changing the sensitivity. The allowed difference is 0.04 division (= 1 pixel). 7. Using toggle the sensitivity of Input B between 5 and 10 mV/div. After changing the sensitivity wait some seconds until the trace has settled. Observe the Input B trace, and check to see if it is set to the same position after changing the sensitivity. The allowed difference is 0.04 division (= 1 pixel). 8. When you are finished, remove the Input A and Input B short. 4.5.2 Input A Trigger Sensitivity Test Proceed as