Philips SCOPEMETER PM93 Service Manual page 5

IV CONTENTS
2.19 MECHANiCAL .............................................................. 2-19
2.20 ENViRONMENTAL .......................................................... 2-19
2.21 INTERFACE (MODEL 97 ONLY) ................................................ 2-21
2.22 SAFETy ................................................................... 2-22
2.23 ACCESSORIES ............................................................. 2-23
2.24 SERVICE AND MAINTENANCE ................................................ 2-23
3 CIRCUIT DESCRIPTIONS ............................................. 3-1
3.1 INTRODUCTION TO CIRCUIT DESCRIPTION ...................................... 3-1
3.1.1 General ............................................................. 3-1
3.1 .2 Location of electrical parts .............................................. 3-1
3.2 FUNCTIONAL BLOCK DESCRIPTION ............................................ 3-2
3.2.1 Introduction .......................................................... 3-2
3.2.2 Data acquisition ...................................................... 3-4
3.3 DIGITAL CIRCUITS (A1) ....................................................... 3-6
3.3.1 Introduction .......................................................... 3-6
3.3.2 Overview digital circuits ................................................ 3-6
3.3.3 MICROPROCESSOR circuitry (IlP) ....................................... 3-7
3.3.4 DIGITAL ASIC (D-ASIC) circuitry ......................................... 3-9
3.3.5 LCD circuitry ........................................................ 3-12
3.4 ANALOG CIRCUITS (A2) ...................................................... 3-14
3.4.1 Introduction ......................................................... 3-14
3.4.2 Overview analog circuits ............................................... 3-14
3.4.3 ATTENUATOR sections, CHANNEL A and B .............................. 3-14
3.4.4 EXTERNAL (BANANA) INPUT/OUTPUT circuitry ........................... 3-18
3.4.5 ANALOG ASIC (A-ASIC) and ADC circuitry ................................ 3-20
3.4.6 ANALOG CONTROL CIRCUIT .......................................... 3-24
3.4.7 GENERATOR circuit. ................................................. 3-30
3.4.8 BATTERY CHARGER ................................................ 3-32
3.4.9 POWER SUPPLY .................................................... 3-34
4 PERFORMANCE VERIFICATION PROCEDURE ........................... 4-1
4.1 GENERAL INFORMATION ..................................................... 4-1
4.2 STANDARD PERFORMANCE VERIFICATION PROCEDURE ......................... 4-2
4.3 STANDARD PERFORMANCE VERIFICATION PROCEDURE SUMMARy ............... 4-16
4.4 ADDITIONAL PERFORMANCE VERIFICATION PROCEDURE ........................ 4-17