Fluke 5725A Car Amplifier User Manual


 
5725A
Instruction Manual
ii
4 Theory of Operation........................................................................... 4-1
4-1. Introduction .......................................................................................... 4-3
4-2. Overall Functional Description............................................................ 4-3
4-3. 1100V AC Range Functional Description....................................... 4-5
4-4. 11A Range Functional Description.................................................. 4-6
4-5. Operation in the 11A DC Range.................................................. 4-7
4-6. Operation in the 11A AC Range.................................................. 4-7
4-7. Voltage and Current Standby Modes............................................... 4-7
4-8. Voltage Standby........................................................................... 4-7
4-9. Current Standby........................................................................... 4-7
4-10. How the 5700A and 5725A Communicate...................................... 4-8
4-11. Description of the Out-Guard Lines (5725A Side) ..................... 4-8
4-12. Description of the In-Guard Lines............................................... 4-9
4-13. Functional Summaries by Assembly................................................ 4-10
4-14. Detailed Circuit Description ................................................................ 4-11
4-15. Interconnect Assembly (A1) ............................................................ 4-11
4-16. Power Supply Assembly (A4).......................................................... 4-12
4-17. High Voltage Supply Section ...................................................... 4-13
4-18. Switching Section........................................................................ 4-14
4-19. Current-Limit Section.................................................................. 4-15
4-20. System Supply Section ................................................................ 4-15
4-21. Fan Supply Section...................................................................... 4-16
4-22. Digital Assembly (A5)..................................................................... 4-16
4-23. Microcomputer ............................................................................ 4-16
4-24. External RAM.............................................................................. 4-16
4-25. External ROM.............................................................................. 4-16
4-26. EEROM ....................................................................................... 4-18
4-27. Data Latch.................................................................................... 4-18
4-28. Strobe Lines................................................................................. 4-18
4-29. Led Driver.................................................................................... 4-18
4-30. Optoisolator Link......................................................................... 4-18
4-31. Break-Detect Circuitry................................................................. 4-19
4-32. Power Up and Reset Circuitry..................................................... 4-19
4-33. Watchdog Timer.......................................................................... 4-19
4-34. Current Amplifier Assembly (A2)................................................... 4-19
4-35. Error Amplifier Section............................................................... 4-21
4-36. Output Stage Section ................................................................... 4-22
4-37. Monitor Section........................................................................... 4-22
4-38. Control and Switching Section.................................................... 4-23
4-39. Power Supply Section.................................................................. 4-23
4-40. High Voltage Amplifier (A3)........................................................... 4-24
4-41. Input Amplifier............................................................................ 4-24
4-42. Integrator...................................................................................... 4-26
4-43. Window Comparator ................................................................... 4-26
4-44. Input Clamp ................................................................................. 4-26
4-45. Transconductance and Cascode Stage......................................... 4-27
4-46. Midstage ...................................................................................... 4-27
4-47. Midstage -400V Filter ................................................................. 4-27
4-48. High Voltage Heat Sink Assemblies ........................................... 4-27
4-49. Autobias Current Source ............................................................. 4-28
4-50. Autobias Sense Circuit ................................................................ 4-28
4-51. High Voltage Amplifier Feedback............................................... 4-29
4-52. Signal Transformers .................................................................... 4-29
4-53. Temperature Monitoring.............................................................. 4-29