Brother MFC9100C Service Manual page 38

3.5 Power Supply PCB
The power supply uses the switching regulator to generate DC power (+24V, +5V, and HVDD)
from a commercial AC power line.
The +24V source is stabilized and fed to the motors and solenoid for feeding documents and
recording paper, as well as to the LED array of the CIS unit.
The +5V source is stabilized and fed to the logic, etc.
The HVDD is fed to the piezoelectric ceramic actuators embedded in the print head. It varies
within 13.7V to 29.4V depending upon the temperature detected by the head thermister.
Power Supply Circuit
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