Samsung SCX4521F - B/W Laser - All-in-One - HVPS Board

Samsung Electronics
Service Manual
System Overview
3-14
4) Power Cord Length : 1830 50mm
5) Power Cord Switch : Exist
6) Feature
- Withstand Resistance : 100 or more (at DC 500V)
- Insulating revisiting pressure : Must be no problem within 1 min. (at1000Vac,10mA)
- Leaking Current : under 3.5mA
- Running Current : under 40A PEAK (AT 25 °C,COLDSTART)
under 50A PEAK (In other conditions)
- Rising Time : within 2Sec
- FallingTime : over 20ms
- Surge : Ring Wave 6KV-500A (Normal, Common)
7) Environment Condition
- Operating temperature range : 0 °C ~ 40 °C
- Maintaining temperature range : -20 °C ~ 40 °C
- Preserving Humidity Condition : 10% ~ 90% RH
- Operating atmospheric pressure range : 1atm
8) EMI Requirement : CISPR, FCC, CE, MIC,
9) Safety Requirement : IEC950 UL1950, CSA950, C-UL, Semko, EK, CB, CCC(CCIB),GOST, EPA,
3.6.2 HVPS Board
The HVPS board creates the high voltage of THV/MHV/Supply/Dev and supplies them to the developer part for
making best quality printing image. The HVPS part takes the 24V and outputs the high voltage such as
THV/MHV/Supply/Dev, and the outputted high voltage is supplied to the toner, OPC cartridge, and transfer roller.
(a) Transfer High Voltage (THV+)
- Input Voltage : 24 V DC +15% / -10% (21.6V~27.6V)
- Out Voltage : +1300KV 1.5% (200 Load )
- Out Voltage Trigger : 6.5
- Input Voltage Variation : 5 %
Load Variation :
5 %
- Out Voltage Rising Time : 100 ms Max
- Out VoltageFalling Time : 100 ms Max
- Transfer Variation Voltage on Environment Variation : +500 V ~ +5000V
- Control Method on environment : THV-PWM ACTIVE, transfer Active signal, of environment sensing
voltage is input and get feed back current, and recalculate it to resistance .
- Control method on transfer output voltage : It is controlled by changing its duty of THVPWM Signal as
follows. 10% Duty : +500V, 90% Duty : +5000V
(b) Charge Voltage (MHV)
- Input Voltage : 24 V DC +15% / -10% (21.6V~27.6V)
- Out Voltage : -1300KV 50V(50 Load)
- Out Voltage Rising Time : 50 ms Max
- Out VoltageFalling Time : 50msMax
- Out Voltage Range : 30 ~ 1000
- Output Control Signal(MHV-PWM) : Active Low PWM signal for controlling MHV