Paper feed motor drive circuit – Epson FX-870/1170 User Manual

Page 143

Principles of Operation

Paper Feed Motor Drive Circuit

The PF motor, a stepping motor, advances the paper at a

minimum

advance rate of

inch. This

motor is a 2-2 phase, constant-voltage, drive motor. CPU ports

are used to control the

PF motor. Phase data for the PF motor is output through these ports. PFA to PFB are turned on
or off within the

depending on the phase data sent from the CPU.

When there is an output at A19 of the CPU, a

V voltage is supplied to the PFCOM terminal

of the PF motor. Otherwise, a V voltage is supplied through to hold the motor.

CPU

Figure 6-28. Paper Feed Motor Drive Circuit

6-28

Epson