ENCAD CADJET 2 Service Manual page 71

Theory of Operation
Chapter 2 THEORY OF OPERATION
1.0 Introduction ........................................................................................................ 2-1
2.0 Mechanical Operation ........................................................................................ 2-2
2.1 Media Axis Drive ............................................................................................. 2-2
2.2 Carriage Axis Drive ......................................................................................... 2-2
3.0 Electrical Operation ............................................................................................ 2-3
3.1 Circuit Assemblies .......................................................................................... 2-3
3.1.1 Main Printed Circuit Board (MPCB).......................................................... 2-3
3.1.2 Front Panel Circuit ................................................................................... 2-3
3.1.3 Carriage Printed Circuit Assembly (Carriage PCB) .................................. 2-4
3.2 Block Diagram ................................................................................................ 2-5
3.3 Power Supply.................................................................................................. 2-6
3.4 Microprocessor ............................................................................................... 2-7
3.5 Start-up Sequence.......................................................................................... 2-8
3.6 Memory........................................................................................................... 2-9
3.7 Flash EPROM............................................................................................... 2-10
3.8 RAM.............................................................................................................. 2-11
3.9 EEPROM ...................................................................................................... 2-11
3.10 Gate Array .................................................................................................. 2-12
3.11 Stepper Motor ............................................................................................. 2-13
3.12 Servo Motor ................................................................................................ 2-15
3.13 Parallel and Serial Ports ............................................................................. 2-16
3.14 Keypad/Display........................................................................................... 2-17
3.15 Carriage Circuits ......................................................................................... 2-18
3.16 LEDs, Beeper, and Fan .............................................................................. 2-19
3.17 Dot Firing Sequence ................................................................................... 2-19
3.18 Schematic Diagrams................................................................................... 2-19
2-20
2-1
CADJET 2