CHAPTER 2
PRINCIPLES OF OPERATION
This chapter describes the operating principles of the circuitry and printer mechanism.
1. Block Diagram ..................................................................................................... 11
2. Interface ............................................................................................................... 13
2-1. Interface Types ..................................................................................................... 13
2-1-1. RS232 interface ................................................................................................ 13
2-1-2. Parallel interface............................................................................................... 14
2-2. Data Arrangement and Printing........................................................................... 15
2-2-1. Arrangement ..................................................................................................... 15
2-2-2. Thermal printhead ............................................................................................ 15
2-2-3. Head current control ........................................................................................ 16
2-2-4. Head current control ........................................................................................ 18
2-2-5. Head burnout protection ................................................................................. 18
2-3. Feed-Motor Drive Circuit...................................................................................... 19
2-4. Power-On Reset Circuit ....................................................................................... 21
2-5. +5V Line Voltage Detector Circuit....................................................................... 22
3. Printer Mechanism .............................................................................................. 23
3-1. Thermal Printhead ................................................................................................ 23
3-2. Paper-Feed Mechanism ....................................................................................... 23
3-3. Detectors ............................................................................................................... 24
3-4. Auto-Cutter Drive circuit (on TSP242-24/120/230 only) .................................... 25
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