Operating Principles For Power Supply Circuit; Power Supply Circuit; Power Supply Components - Epson EPL-N4000 Service Manual

EPSON EPL-N4000/EPL-N4000+
2.6 Operating Principles for Power Supply
Circuit

2.6.1 Power Supply Circuit

The power supplies in this printer provide the voltages that the printer
requires to operate. The various printer functions require 110VAC,
+5VDC, +24VDC, and several high voltage DC and AC values that are
used by xerographics.
The printer AC power cord plugs into a grounded AC wall outlet. The
cord carries AC line voltage to the Noise Filter PWB. The Noise Filter
smooths the AC voltage and sends it to the Main Power Switch.
Switching on the Main Power Switch applies AC voltage to the AC
Driver PWB and to the Low Voltage Power Supply (LVPS) PWB.
The AC Driver PWB is the interface between printer control (MCU) and
the Fuser. Fuser sensors connected to the AC Driver PWB send Fuser
status information to the Driver PWB, which the PWB routes to the MCU
PWB. The MCU processes the information and sends commands back
to the AC Driver PWB to tell the AC Driver whether or not to switch on
the Fuser Heat Rods.
The Low Voltage Power Supply PWB, or LVPS, converts the 110VAC
to regulated +24VDC and +5VDC voltages. The LVPS sends these
voltages to the MCU PWB. The MCU uses the voltages for internal
processing and for printer component operation. The MCU also sends
+24VDC to the High Voltage Power Supply PWB.
The High Voltage Power Supply PWB, or HVPS, converts the
+24VDC received from the MCU PWB to the high voltages that are
required by the xerographic system of the printer. The HVPS produces
Rev.B
the Charge (CR), Transfer (TR), Developer Bias (DB), and Detack
(DTS) voltages, and sends them on to the EP Cartridge and to the Bias
Transfer Roll (BTR).
Figure 2-36. Power Supply Circuit

2.6.2 Power Supply Components

This printer is made up of five main components and a number of
subcomponents.


Noise Filter PWB
Smooths and removes any fluctuation or hum from the AC line
voltage.
Main Power Switch: Used to switch AC voltage on and off
(switches the printer on and off).


AC Driver PWB
Receives smoothed AC voltage from the Noise Filter. The AC Driver
PWB receives Fuser temperature information from Fuser sensors
and passes that information on to the MCU for processing. The
MCU PWB commands the AC Driver to switch on or switch off AC
voltage to the Fuser Heat Rods.
Chapter 2 Operating Principles
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