Discipline: EngineeringPeripherals Focus motors (3) Auto-guider deployment motor (1) Proximity sensors (8) Fan Control (2 banks, 3 fans each) Fan Tach Input (6) Temperature Sensor ADC (1, 8 channels) Design Assumptions Focus Startup Assume in position Do not move Motor Backlash To minimize motor backlash, always approach a new position from the same direction Always approach moving OUT Drive Characteristics 200 steps/rotation (360 degrees) 10:1 gear reduction 20 threads/inch screw drive Collimation Adjustment in either North-South or East-West axes Keep center of mirror in place (i.e. can't move just one side) East-West adjustment involves only E-W motors North-South adjustment involves all three motors Account for the fact that E-W motors are closer to plane of rotation than N motor when adjusting N-S. Distances from plane of rotationN motor: 9.830 E-W motors: 4.915 Ratio: 2:1 Maximum tilt offset - 8mm Dew Heater Not simple On/Off Take inputs Duty cycle Period Fans Two banks of fans Rear OTA fans Stir fans Rear OTA fans default on Stir fans default off Tags: softwareblackfin0.4m
