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7) Printer motor drive circuit
VP
7
+20
BLOCK diagram
VFI, VF2
:
-4.3VAC
VDISP
-25V
voc
+5V
VDD
7
+8V
Power
leceenr
{2) Regulator circuit
Fig. 2-9
pea
From wPO76212
A high on P22 of the 4PD75212 makes TRS active and TR4
inactive so that current flows through the motor to run. On the
other hand, a low on P22 turns off TR3 and turns on TR4 stop the
motor.
Fig. 2-12
8) Drawermagnet drive
1) If VO-P-ON was not shorted within the mode switch (power
off), TR1 remains inactive as no voltage is applied to the base
of TR1.
2) If VO-P-ON was shorted, TR1 goes active as voltage is added
to the base of TRI.
3) With activation of TRI, the voltage VM begins to increase.
(8) DC-DC converter
@ o
uPD75217
15K
R25
Fig, 2-10
205
De
The drawer magnet isdriven when P23 of the pPD75212 changes
®)
from low ta high state
bod
Fig. 2-13
9) Power circult
'The bias is added to the base of TRS when the power switch is
tumed on, so that TRS starts self-oscillation. VLOAD from the
(1) Block diagram
secondary side is fed back through the zener diode ZD3 to
suppress voltage fluctuation on the secondary side.
Fig. 2-11
Se iti>
:
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