Reset circuit – Epson FX-870/1170 User Manual

Page 140

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Principles of Operation

Reset Circuit

The control circuits are initialized when the RESET signal is issued. The reset operation occurs
under these two conditions:

1. Power on reset

Immediately after the power is turned on,

VDC is rapidly generated. Because it takes a

moment for the voltage at

to reach

V, the voltage at the DISC terminal on the gate

array does not reach VDC until capacitor C24 is fully charged. A similar integration circuit
is provided in the gate array and further delays the output of the ROUT signal. This LOW
level is used as a reset signal.

signal reset

The reset signal is also issued when the

signal is sent

the host computer.

Figure 6-25 shows the power on reset circuit.

RIN

DISC ROUT

I 15

Epson FX-870/1170

6-25