Printronix L5000 Series Maintenance Manual page 287

The TPOS signal validates drive pulses of both the current switch–over signal
(PMDRV) and the various motor phases, along with turning the power supply relay
on.
The current switch–over unit switches over the comparator voltage of the current
detection voltage V8 by this PMDRV signal, between motor drive and detent
conditions, as follows:
when in motor drive:
when in detent:
As a result, the current flowing to the motor becomes a constant current with slight
ripples of 1.5A/phase and 0.8A/ phase, from the current detection voltage V8 being
controlled to the above level by the comparator. At this time, the relationship
between comparator output voltage VA and current detection voltage V8 is as shown
in the following graph.
As this motor is a 2–phase excitation type, the drive pulse is as shown in the
following chart.
(in positive rotation)
TPFA10
TPFB10
TPFA11
TPFB11
(in negative rotation)
Electrical and Wire Data
0.99v
0.53v
1 2
1 1
0 1
0 0
1 0
3 4
0 0
1 0
1 1
0 1
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