Fuser Ac Power Control - Xerox Phaser 3250 Service Manual

Fuser AC Power Control

Phaser 3250 Laser Printer Service Manual
Power Consumption
No. Item
1 Standby
2 Printing
3 Sleep Mode
Length of Power Cord: 1830
Power Switch: Use
Feature:
Insulating Resistance: 100 M
Withstanding Voltage: Must be no problem within 1 min.
(at 1000V-LV model/1500Vac-HV model, 10 mA)
Leaking Current: Under 3.5 mA
Running Current:
* Under 40 A PEAK (at 25° C, COLD START)
* Under 60 A PEAK (in other conditions)
Rising Time: Within 2 Sec.
Falling Tine: Over 20 ms
Surge: Bi-Wave 3kV - Normal, 6kV - Common
The Fuser receives heat from AC power, which controls the switch with the
Triac, a semiconductor switch. The On/Off control is operated when the gate
of the Triac is turned On/Off by Phototriac (insulting part). In other words, the
AC control part is passive circuit, so it turns the heater On/Off while retrieving
signal from the engine control part.
When the Heater On signal is turned On at the print engine, the LED of
PC501 (Photo Triac) measures the voltage and flashes. From the flashing
light, the Triac part (light receiving part) measures the voltage, and the voltage
is supplied to the gate of Triac and flows into the Triac. As the result, the AC
current flows in the Lamp, and heat is generated.
On the other hand, when the signal is Off, the PC501 is Off, the Triac is cut off
at the gate of Triac. When the Triac turns Off, the Lamp is turned Off.
Triac (Q501) Feature: 24A-LV model/16A-HV model, 600 V Switching
Phototriac Coupler (PC501)
Turn On if Current: 15 mA~50 mA (Design: 16 mA)
High Repetitive Peak Off State Voltage: Min 600 V
System
Less than 70 W
Less than 550 W
Less than 11 W
± ±
50 mm (72.0 1.9 in.)
Ω
or more (at DC 500 V)
Theory of Operation
2-23