Theory Of Operation - Fluke 45 Service Manual

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
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

Theory of Operation

Title
Chapter 2
Page
2-1