Elevator Motor Encoder (Eme) - Printronix L5535 Maintenance Manual

Appendix C
Control Principles
Stacker Motor Encoder (SME),

Elevator Motor Encoder (EME)

These sensors detect abnormal DC motor revolution. Each sensor consists of
a timing disk attached to the motor axis, a light emitter, and a light receptor.
The motor revolution is monitored by the length of time that blockages of light
occur between the light emitter and receptor.
Motor
II–284
Timing Disk
Light Emitter
and Receptor