Theory Of Operation - Fluke 78 Service Manual

2-1. Introduction ............................................................................................ 2-3
2-2. Functional Block Description................................................................. 2-3
2-3. Circuit Descriptions................................................................................ 2-4
2-4. Input Overload Protection.................................................................. 2-4
2-5. Rotary Knob Switch........................................................................... 2-4
2-6. Input Signal Conditioning Circuits .................................................... 2-4
2-7. Volts Functions.............................................................................. 2-4
2-8. Ohms Function .............................................................................. 2-5
2-9. Continuity ...................................................................................... 2-6
2-10. Temperature Function.................................................................... 2-6
2-11. Diode Test Function ...................................................................... 2-7
2-12. RPM Function................................................................................ 2-7
2-13. Current Function............................................................................ 2-7
2-14. Analog Section of Integrated Multimeter IC (U1) ............................ 2-7
2-15. Frequency Measurements .............................................................. 2-9
2-16. Dwell and Duty Cycle Measurements ........................................... 2-9
2-17. Microcomputer Control ..................................................................... 2-9
2-18. Peripherals to U1................................................................................ 2-9
2-19. AC Buffer ...................................................................................... 2-9
2-20. AC converter.................................................................................. 2-9
2-21. Active Filter................................................................................... 2-9
2-22. A/D Converter ............................................................................... 2-9
2-23. Beeper ............................................................................................ 2-10
2-24. Power Supply................................................................................. 2-10
2-25. Display ............................................................................................... 2-10

Theory of Operation

Title
Chapter 2
Page
2-1