Ribbon Deck - Printronix

P9212 Maintenance Manual

Ribbon Deck

The printer ribbon winds and unwinds continuously on a pair of spools
latched to hubs driven by the ribbon motors. The ribbon motors operate only
while the hammer bank assembly is running. Ribbon motion reverses when
the metal strip at either end of the ribbon crosses the left or right ribbon
guide, completing a circuit that causes both motors to reverse direction.
Constant ribbon tension is maintained by controlling each motor with a drive
or drag circuit. While the hammer bank assembly is in motion, one motor
acts as a driving motor, drawing the ribbon against the resistance exerted by
the other motor—the drag motor. This system maintains a constant motor
speed and constant ribbon tension.
Figure 2–23. Ribbon Deck
Principles of Operation 2–41