Panasonic KX MC6020 - Color Laser - All-in-One - HVU (High Voltage Power Supply Board) Section

107
KX-MC6020HX
6.17. HVU (High Voltage Power Supply Board) Section
6.17.1. High Voltage Circuit
This board outputs 12 high voltages used for electronic photographic process. The 12 voltages consists of 2 charge ( VCH/YMC,
VCH/K : -1001V ~ -1405V ) for color (YMC) OPC and black OPC, 4 development bias ( VB/Y, VB/M, VB/C, VB/K : DC -100V ~ -
300V + AC400V
p-p
) for each color, 4 supply bias ( VSR/Y, VSR/M, VSR/C, VSR/K : -200V ~ -400V), FTR bias ( FTR : 0V ~ 1800V
), STR bias ( STR : 0 ~ 5000V ). The Charge, Development bias, FTR Bias and STR Bias voltages are varied by the D/A converter
setting data from the main board. If the signal HVEN is a low, 2 Charge, 4 Development Bias, 4 Supply Bias, FTR Bias and STR
Bias voltages are generated. Each of the high voltages are specifically set depending on the print media, selected resolution, print-
ing mode, duplicate mode, and humidity/temperature range of the room. The humidity and temperature are detected by a humidity
sensor.
6.17.2. Charge Control Circuit
This circuit consists of a DC-DC converter, which boosts +24V to approximately -1001V ~ -1405V for the charge bias (maximum
current rating 50µA for each color). This circuit has 2 boost circuits (VCH/YMC : Color, VCH/K : Black). The VCH/YMC and
VCH/K voltages are controlled individually by the D/A converter circuit on the high voltage board.
OUTPUT VCH/K VCH/YMC VB (K.C.Y.M) VB(+)
CONTROL METHOD C.V. C.V. C.V. (AC+DC) ZD
NOMINAL OUTPUT VOLTAGE -1203V±24V -1203V±24V AC:400V[P-P]±50V[P-P]
(When 800Hz)
DC:-200V±10V
200V±25V
NOMINAL LOAD
40M
Ω 13.3MΩ 200
p
F//100MΩ 10GΩ
LOAD AREA
24M
Ω ~ 10GΩ 8MΩ ~ 10GΩ
--- ---
OUTPUT VOLTAGE RANGE -1001V±20V~ -1405V±28V -1001V±20V~ -1405V±28V DC:-100V±10V~ -300±10V ---
OUTPUT CONTROL DAC DAC AC: Fix
DC:DAC
Fix
OUTPUT VSR (K.C.Y.M) VSR(+) FTR STR(+) STR(-)
CONTROL METHOD VB(-)+ZD --- C.V. CC/0V ZD
NOMINAL OUTPUT VOLT-
AGE
-300V±20V 200V±25V 597V±30V CC 10µA±0.6µA
0V mode
0V±100V
(VCHK= min when
setting)
-500V±50V
(VCHK= min when
setting)
NOMINAL LOAD 100MΩ 10GΩ 10GΩ CC 150MΩ 500MΩ
LOAD AREA --- --- --- 500V ~ 5000V ---
OUTPUT VOLTAGE
RANGE
-200V±20V~ -
400V±20V
--- 0V±20V~
1800±50V
CC 1.5µ A ~100µA---
OUTPUT CONTROL DAC Fix DAC DAC Fix