Rev.D Product Overview Appendix D-67
TM-U675/U675P (with autocutter) Service Manual
Confidential
Rush Current Control Circuit
The rush current control circuit controls rush current when the power source is turned on. This
printer has large-capacity condensers to facilitate stable operation of mechanism drivers and
circuits. Therefore, an excess of rush current is generated when the power is turned on. This
circuit controls the rush current.
An external power supply is connected to the CN18. A switch is connected to CN29. When the
switch is turned ON, the voltage at Q61 Gate-Source is “0” because Q61 is OFF and C605 is not
energized. For that reason, there is no current flowing. After that, the voltage to Gate-Source
gradually rises according to the time constant determined by C605 and R245 to gently raise the
output voltage. This restricts the sudden flow of current to the capacitors.
Figure D-64 Rush Current Control Circuit
R245
L3
CN29
1
2
C44
C605 R244
C43
F1
C42
D16
Q61
CN18
1
2
3
SH
C40
24VB
C41
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