TCS3 Encoder Review

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TCS3 Encoder Review

• Web Page Reference
• http//irtfweb.ifa.hawaii.edu/tcs3/systems/tcs3/0
  309_Design/06_Encoders/
• Requirements
• APE (Absolute Position Encoder) Match present
  APE accuracy 6 arc seconds.
• IPE (Incremental Position Encoders) Servo
  model shows the current IPE resolution of 20
  count/arcseconds can sufficiently meet the 0.1
  arcsec resolving requirement.

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TCS3 Encoder Design Highlights.

• APE Design Highlights
• Sensors (Resolver/Transductor) is embedded in the
  telescope shaft. TCS3 will re-use sensor.
• Plan is to switch sensor between TCS1 TCS3
  readout electronics.
• TCS3 purchased new readout electronics.
• TCS3 electronic to be installed in parallel with
  TCS1.
• Embedded CPU to correlate and provide APE data
  via RPC. Embedded CPU to sample APE data at 20Hz.
  TCS3 to query embedded CPU at 10 Hz.
• Spare sensor parts purchased (transductor and
  resolver), but we could not replicated the
  mount/case.
• After tcs3 switch over, APE input to TCS1 will be
  disabled.
• IPE Design Highlights
• 1. Use the current IPE.
• 2. Route IPE output to both TCS1 and TCS3. (TTL
  pulses)
• 3. Improvement to IPE must wait until TCS1 is
  decommissioned (or may not be part of this
  upgrade).

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Ape_plan
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Block_diagram
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APE Schematic
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APE Lab Setup
Transducers
Embedded PC
Converter/preamp (transducer)
Converter (resolver)
Resolver