Circuit Description; Pwa Block Diagram; Functional Description - Toshiba KK-1600 Service Manual

5. CIRCUIT DESCRIPTION

5.1 PWA Block Diagram

STP cover open
switch
STP AC adapter

5.2 Functional Description

The STP operates the stapler through the STP controller PWA. When the power of the copier is turned on,
a power supply is also delivered to the STP to enable stapling. When paper is loaded into the stapler, the
STP paper set sensor detects the presence of paper (changing from "High" to "Low"), and 200 ms later the
CW signal turns ON (changing from "Low" to "High") to operate the STP motor forward. When the motor
operates, the gears and cams of the stapler operate for stapling. When the STP home position sensor
detects the home position of the stapler (changing from "High" to "Low") after the CW signal is activated, the
CW signal turns OFF.
If the STP home position sensor remains at "High" level (a failure to return to the home position) for some
reason even if a fixed time (approx. 900 ms) has elapsed after the CW signal turns ON, the CW signal turns
OFF and 100 ms later the CCW signal is turned ON (changing from "Low" to "High") to operate the STP
motor reversely. In practice, however, if the STP has locked up mechanically, an overload occurs so that
the fuse installed on the STP CONT PWA will blow or the protective circuit of the AC adapter will function
to cut the delivery of the power supply (shutdown).
If the stapler is not at the home position when the power is turned on ("High" level), about 60 ms later the
CCW signal is turned ON (changing from "Low" to "High") to operate the motor reversely allowing the stapler
to return to the home position.
October 2000 © TOSHIBA TEC
1
24V
2
Q3
FU1
switching
1
regulator
2
3
GND
PAPER_SENS
STPL_H/P
HOOK_SW
24V
Motor
controll
circuit
5V
GND
5V
5V
GND
GND
5V
GND
Motor drive CW
circuit
CCW
Motor drive
circuit
5 - 1
1
STP LED PWA
2
1
STP paper set
2
sensor
3
1
2
3
4
STP sensor PWA
5
6
7
STP 05-01-01
KK-1600 CIRCUIT DESCRIPTION