Motor Driver Circuits - Epson Stylus COLOR 800 Service Manual

2.3.2.3 Motor Driver Circuits

This printer is equipped with the 3 motors; CR motor, PF motor, and pump motor. Since they are all driven
by the UDN2917EB, they use the same control system.
‰CR motor driver circuit
The phase control signal for the CR motor is converted into the UDN2917EB Micro-step bipolar driver
system at the IC2 gate array, then output from the port 55 to the port 43 and 26 of the IC13
UDN2917EB. IC13 determines the phase mode according to the signal sent. The current control
signal is also produced in IC2 gate array and output from the port from 51 to 54 to the port 1, 2, 23 and
24 of the IC13 UDN2917EB.
‰PF motor driver circuit
The motor driver circuit for the PF motor is the same as for the CR motor.
‰Pump motor driver circuit
The motor driver circuit for the Pump motor is the same as for the CR motor.
Rev. A
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Figure 2-22. CR Motor Driver Circuit
Operating Principles
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