Mita-Kyocera ST20 CHAPTER3

Chapter 3

Paper specifications

Chapter 3 Contents

3-1 Introduction ...................................................................................................................................... 3-3

3-2 Power supply/motor driver board .................................................................................................. 3-4

3-2-1 Power supply circuit........................................................................................................................ 3-4

3-2-2 Motor driver circuit .......................................................................................................................... 3-5

3-3 Controller board............................................................................................................................... 3-6

3-3-1 Solenoid driver................................................................................................................................ 3-7

3- 4 Printer interface .............................................................................................................................. 3-8

3-4-1 Connector configuration.................................................................................................................. 3-8

3-4-2 Controller board CPU I/O interface................................................................................................. 3-9

3-5 Sensors........................................................................................................................................... 3-11

3-6 Error message................................................................................................................................ 3-12

3-7 Printing timing charts.................................................................................................................... 3-13

3-1 Introduction

This chapter explains the operation of the electrical circuits in the bulk stacker. Procedures for
hardware troubleshooting are also included in this chapter. Schematic diagrams are provided in
Appendix. The schematic diagram should be referred to along with the explanation in the following
pages.

The electrical system of the bulk stacker can be functionally divided in the following two parts:

Power supply/motor driver
Controller

These two part are mounted on separate circuit-boards. Details on each part follow are explained
on the following pages.

3-3

ST-20

3-2 Power supply/motor driver board

See figure 3-2-1 below. The motor driver/power supply board is located on the top of the bulk
stacker, inside the top plate.

Power supply/motor driver board

Figure 3-2-1 Location of power supply/motor driver board

3-2-1 Power supply circuit

See appendix power supply/motor driver board circuit diagram.

The bulk stacker has no power switch provided as the printer's power switch simultaneously activates
the bulk stacker's power supply. When printer power turns on, the 5 V DC reaches at pin #3 of the
interface connector. It activates and closes relay RL1 on the motor driver/power supply board
which in turn connects the primary power (120 or 220 V AC) to transformer T1. The power supply
section produces both the 5 V and 24 V DC and feeds them accordingly to the respective circuits.
Regulator IC1 is provided for the 5 V DC power supply.

ST-20

3-4

3-2-2 Motor driver circuit

See appendix power supply/motor driver circuit board diagram.

The motor driver receives commands for driving the feed motor from the controller board through
connector J1.

The feed motor is located on the top of the bulk stacker, inside the top panel. The feed motor drives
the feed roller for feeding paper arriving from the printer towards the paper tray. Power voltage for
this motor is regulated by means of resistors R11 and R14 on the power supply/motor driver board
so as to obtain a constant 16 V DC source. The feed motor turns on when the level of pin #9 of J1
(FEEDON*) becomes low.

3-5

ST-20