Power Supply System; Protection Functions - Sharp AR-FN8 Service Manual

CHAPTER 2 FINISHER UNIT BASIC OPERATION
III. POWER SUPPLY SYSTEM
1. Outline
The finisher controller PCB is supplied with 24 V C and 5V C power when the host machine
is turned on, 24V C is used to drive the motor solenoids. 5V C is used for sensors and ICs.
24V C and 5V C are also used to feed power from the finisher controller PCB to the saddle
stitcher controller PCB. Power is also supplied to the punch driver PCB when the optional puncher
unit is mounted.
Some of the 24 V C power used to drive the motors is cut off when the door switch (MS1) is
open. The power to the saddle stitcher controller PCB, however, will not be cut off.
Figure 2-301 is a block diagram showing the power supply system.
Host
machine
2.

Protection Functions

The 24 V C power line used to drive motors and solenoids is equipped with a circuit breaker
(CB1) for protection against overcurrent. The 24 V line used to drive the first feed motor (M1),
alignment motor (M3), and stapler shift motor (M4) are equipped with a fuse, which is designed to
blow when an overcurrent occurs.
2-56
Saddle stitcher Door switch
controller PCB
(Saddle Finisher)
Circuit breaker
(CB1)
Finisher controller PCB
(Q14)
Regulator IC
Figure 2-301
(MS1)
Motor
Motor
Solenoid
Sensors
Logic
5V
Punch driver PCB
24V
(Puncher Unit (option))