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Hour Angle Drive


Table 3.19: Hour Angle Drive Specifications
Drawing: RCT001/1
EOS Drawing:  
Motor: "good quality" DC servo with analog tachometer output.
Velocity encoder: gBEI
Motor Encoder: incremental with index
Overall encoder: Heidenhain RON 806 36,000 line count EXE 660 exploder connected and exploder 400:1
Limits: two-level East and West.
  -108 to +175 degrees feasible
  -80 to +160 degress because cables
  -78 to +158 safe
  the normal limits are for channel 1, the FS limits are channel2
HA Controller: PMAC#1
HA Drive Amplifier: Amp 1 Copley (413)
Scale: 160,000 ppdeg
Home corr: is closed west (light is on) very close to meridian
Home pulse: 6.65 west
Slew: 1 degree per second 0.1 deg/sec/sec acc
Gear: 480 tooth

These encoders have a failure report. Two-level limits means an inner one that is used by the software and an outer one that does something more drastic.
Figure 3.24: Photo of the Hour Angle Drive
Image HaDrive



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Next: Hour Angle Preload Up: Telescope and other Devices Previous: Guide Camera   Contents
Louis-Gregory Strolger 2012-01-09