High Voltage Output Control Circuit; Outline; Control Method - Toshiba DP1600 Service Manual

11.5 High Voltage Output Control Circuit

11.5.1 Outline

This section describes the control circuit for each bias voltage and current for charging, development,
transfer, and separation.
Main PWA
26
28
IC6
IC66
I/O port
14
CPU
GA-2
33
59
IC34
61
System
60
control GA

11.5.2 Control method

Charging (Grid)
The CPU (IC66) loads reference voltage data for the grid into the register of the system control GA (IC34).
↓
The system control GA converts the data loaded into the register to a DI signal (ADC setting signal) in
serial format and sends it to the D/A converter (IC17) at the timing of the CLK signal (transfer clock signal)
and the LD signal (load data signal).
↓
The D/A converter converts the input data to a GVR signal (grid reference voltage signal) in analog form
and sends it to the HVPS.
↓
The HVPS generates high voltage based on the voltage value of the GVR signal and delivers it to the grid.
Charging (Main charger)
The I/O port GA-2 (IC6) turns the CCON signal (main charger control signal) to "Low" level.
↓
The HVPS generates constant-current and delivers it to the main charger.
1600/2000/2500 DRUM-RELATED SECTION
IC11
CHO
3 4
THVCN
11 10
PG
13 12
SP
2 4
DI
17 2
3
IC17
LD
15
19
D/A converter
CLK
16 5
Relay PWA
CCON
74 74 1
DVVR
75 75 2
TCON
76 76 3
TCVR
77 77 4
GVR
78 78 7
SPON
79 79 8
SPDVR
80 80 9
PGON
82 82 10
11 - 4
Main charger
Magnetic roller
Transfer charger
HVPS
Grid
Separation charger
Pinch roller
Paper guide plate
11-05-01
December 2000 © TOSHIBA TEC