Power On/Off - Epson LQ-1050 Technical Manual

2.3.1.2 Power ON/OFF

When the power is switched on and Vx rises, voltage is applied to the integration circuit (composed
of R88, C26, D48). The voltage at C26 increases according to
reaches Vp the output is switched from low to high (Schmitt trigger), and the reset circuit in the MMU
sets the ROUT signal high (TR 1 ). The reset (ROUT) signal is sent to the IC'S on the MONMA board and
to the outside via CN2 and CN4. D47 is a diode used to discharge C25.
When the power is switched off, the voltage at C26 decreases according to
when reaches
the ROUT signal low.
Figure 2-24 shows the waveform for this operation.
the
output is switched from high to low, and the reset circuit in the MMU sets
V
N
AT POWER ON
1
THLD
5 ~1'
ROUT
o
RESET
Fig. 2-24. Power ON Reset
AT POWER OFF
t,
C P U O P E R A T E S
2-23
-
Vx ( 1 – e ~) and when VTHLD
=
Vx (e-~ – 1) and,
1
—
RESET
REV.-A