Phaser 3250 Laser Printer Service Manual 2-23
Theory of Operation
Power Consumption
■ Length of Power Cord: 1830 ± 50 mm (72.0 ± 1.9 in.)
■ Power Switch: Use
■ Feature:
■ Insulating Resistance: 100 M Ω or more (at DC 500 V)
■ 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
Fuser AC Power Control
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
No. Item System
1 Standby Less than 70 W
2 Printing Less than 550 W
3 Sleep Mode Less than 11 W