HP LaserJet Enterprise 500 Maintenance Manual - Page 230

AC Power

Page 230 highlights

Chapter 7 Power Supply Board The printer uses five motors: two ribbon drive, one paper feed, one platen open, and one shuttle motor. The shuttle motor is a brushless DC motor driven by current control. The MPU encoder is used as feedback for motor commutations, hammer fire timing, and motor stall detection. The paper feed motor is a DC stepping motor driven by current control. The paper feed motor may be driven in full, half, or microsteps, depending on print requirements. The ribbon system uses two DC stepping motors that alternate drive and drag roles when the ribbon reaches turnaround. The drive ribbon motor is microstepped in voltage mode, while the drag motor is loaded and monitored to maintain correct linear speed and tension. The platen motor is driven in current mode and can be full or half stepped. The overall current level may be reduced for standby modes. The paper feed, ribbon drive, and shuttle motors are driven in control loops containing power MOSFETs, voltage and current sensors, the MECA ASIC, and the EC processor. The platen motor is driven by a stepping motor controller IC and the EC processor. Control of the hammer drive is split between the controller board and the hammer bank. Common circuits are located on the controller board, while hammer specific circuitry is contained on the hammer bank. The EC uses the MECA ASIC on the controller board to set timing and upper drive profiles for hammer fire events. The controller also contains diagnostic circuitry for the hammer system. The hammer bank contains HBA ASICs that interpret fire commands and data from the MECA and VX ASICs. The HBAs control lower drive MOSFETs on the hammer bank. These determine which hammers will participate in a fire event generated by the controller's upper drive. Power Supply Board The printer power supply is contained on a printed circuit board mounted in the card cage. The power supply automatically senses and adjusts to any commercial electrical system that provides AC mains potential in 50 or 60 Hertz systems. In other words, the printer can operate anywhere in the world on local commercial power. The power supply converts alternating current (AC) to direct current (DC) at three voltage levels and sends the DC voltages to the controller board. The controller board distributes all DC power to the logic and electromechanical circuits. AC Power The power supply operates on AC voltages ranging from 88 volts to 270 volts. It can tolerate variations in frequency of 47 to 63 Hz. The power supply is designed to withstand an AC input overvoltage of 300 VAC for one second with no degradation of DC output voltage or damage to printer circuits. 230

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230
Chapter
7
Power Supply Board
The printer uses five motors: two ribbon drive, one paper feed, one platen
open, and one shuttle motor. The shuttle motor is a brushless DC motor
driven by current control. The MPU encoder is used as feedback for motor
commutations, hammer fire timing, and motor stall detection. The paper feed
motor is a DC stepping motor driven by current control. The paper feed motor
may be driven in full, half, or microsteps, depending on print requirements.
The ribbon system uses two DC stepping motors that alternate drive and drag
roles when the ribbon reaches turnaround. The drive ribbon motor is
microstepped in voltage mode, while the drag motor is loaded and monitored
to maintain correct linear speed and tension. The platen motor is driven in
current mode and can be full or half stepped. The overall current level may be
reduced for standby modes.
The paper feed, ribbon drive, and shuttle motors are driven in control loops
containing power MOSFETs, voltage and current sensors, the MECA ASIC,
and the EC processor. The platen motor is driven by a stepping motor
controller IC and the EC processor.
Control of the hammer drive is split between the controller board and the
hammer bank. Common circuits are located on the controller board, while
hammer specific circuitry is contained on the hammer bank. The EC uses the
MECA ASIC on the controller board to set timing and upper drive profiles for
hammer fire events. The controller also contains diagnostic circuitry for the
hammer system. The hammer bank contains HBA ASICs that interpret fire
commands and data from the MECA and VX ASICs. The HBAs control lower
drive MOSFETs on the hammer bank. These determine which hammers will
participate in a fire event generated by the controller’s upper drive.
Power Supply Board
The printer power supply is contained on a printed circuit board mounted in
the card cage. The power supply automatically senses and adjusts to any
commercial electrical system that provides AC mains potential in 50 or 60
Hertz systems. In other words, the printer can operate anywhere in the world
on local commercial power.
The power supply converts alternating current (AC) to direct current (DC) at
three voltage levels and sends the DC voltages to the controller board. The
controller board distributes all DC power to the logic and electromechanical
circuits.
AC Power
The power supply operates on AC voltages ranging from 88 volts to 270 volts.
It can tolerate variations in frequency of 47 to 63 Hz. The power supply is
designed to withstand an AC input overvoltage of 300 VAC for one second
with no degradation of DC output voltage or damage to printer circuits.