Ac Inlet & Power Switch/Filter & Power Supply Section; Sa Main Pcb; Operation Panel (Sa Lcd Pcb); Thermal Print Head (Sa2 Head) - Citizen CL-S400DT Technical Manual

Major functions of individual components are described below:
(1) AC Inlet & Power Switch/Filter & Power Supply section
Consists of a fuse and filter circuit to eliminate external electric noise and a switching type
regulator to transform an AC input to +24V DC output.

(2) SA Main PCB

Controls the entire operation of the printer. It consists of CPU, Flash ROM, S-DRAM, FPGA,
driver circuits, etc.
(a) CPU
The CPU is a microprocessor with 32-bit architecture. The clock fed to the CPU is 16 MHz.
The CPU internally multiplies this 16 MHz by 8 times and uses 128 MHz clock. The CPU
includes cache memory, RAMs, DMA controller, serial I/F, USB function controller, A/D
converter, etc.
(b) Flash ROM
This is a flash ROM of 32M bits (4M bytes) that stores the firmware and CG (character
generator).
(c) S-DRAM (Synchronous dynamic RAM)
This is an S-DRAM of 128M bits (16M bytes) that is used as working area, input buffer and
download buffer.
(d) FPGA (Field Programmable Gate Array)
The FPGA incorporates control circuits for the interface I/O port, motor, print head, etc.
(e) Stepping motor driver
This is a circuit to drive the "Unit, Motor" (stepping motor).
(f) Buzzer
The buzzer is driven when an alarm, etc. occurs.

(3) Operation panel (SA LCD PCB)

This is a panel used to indicate the operating status of the printer and to set specifications. It
consists of 4 keys, 1 LED (Green/Red) and 1 LCD.

(4) Thermal print head (SA2 Head)

The thermal print head has the following thermal elements. It also has the print head driver
circuit.
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Chapter 2 Operating Principles
2-2. Operation of Control Parts
CL-S400DT