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This FAN is used to radiate heat in the unit.
The signal level at pin J25/H25 of IC101 becomes high, the FAN is activated. In this case, the pulse signal as shown below input
to pin G25 of IC101 and the rotation of the FAN is detected.

This unit is equipped with fan to prevent the developing device from rising in temperature while printing.
The air is inhaled from the right side of the unit.
The fan rotates at high speed (Approx. 3000 rpm) while printing (controlling the developing device). After printing is finished, it
rotates at low speed (Approx. 2200 rpm) when the temperature of the unit goes up over a fixed one or depending on the number
of printed papers (frequency).
While the fan is rotating at high speed, the voltage of Approx. 21 V is supplied to the fan, however, while rotating at low speed,
the supply voltage is decreased to Approx. 12V.

Each signal wave is as follows:
1. High-speed rotation (typ. 3000 rpm)

2. Low-speed rotation (typ. 2200 rpm)

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The solenoid drive circuit controls the pick-up clutch.
The solenoid is designed to be driven by +24V, driven by IC101-B12 pin.
Diode D203 protects Q229 from backward voltage when the solenoid is driven.

Mode

IC101-B12 pin

SOLENOID ON

high level

SOLENOID OFF

low level

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