Voltage linear transformation circuit design

Lucas R.W. Sanchez, Moon Seob Jin, R. Phillip Scott, Ryan J. Luder, Michael Hart

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Many engineering projects require automated control of analog voltages over a specified range. We have developed a computer interface comprising custom hardware and MATLAB code to provide real-time control of a Thorlabs adaptive optics (AO) kit. The hardware interface includes an op amp cascade to linearly shift and scale a voltage range. With easy modifications, any linear transformation can be accommodated. In AO applications, the design is suitable to drive a range of different types of deformable and fast steering mirrors (FSM's). Our original motivation and application was to control an Optics in Motion (OIM) FSM which requires the customer to devise a unique interface to supply voltages to the mirror controller to set the mirror's angular deflection. The FSM is in an optical servo loop with a wave front sensor (WFS), which controls the dynamic behavior of the mirror's deflection. The code acquires wavefront data from the WFS and fits a plane, which is subsequently converted into its corresponding angular deflection. The FSM provides ±3° optical angular deflection for a ±10 V voltage swing. Voltages are applied to the mirror via a National Instruments digital-to-analog converter (DAC) followed by an op amp cascade circuit. This system has been integrated into our Thorlabs AO testbed which currently runs at 11 Hz, but with planned software upgrades, the system update rate is expected to improve to 500 Hz. To show that the FSM subsystem is ready for this speed, we conducted two different PID tuning runs at different step commands. Once 500 Hz is achieved, we plan to make the code and method for our interface solution freely available to the community.

Original languageEnglish (US)
Title of host publicationAstronomical Optics
Subtitle of host publicationDesign, Manufacture, and Test of Space and Ground Systems
EditorsTony B. Hull, Pascal Hallibert, Dae Wook Kim
ISBN (Electronic)9781510612594
StatePublished - Sep 7 2017
EventAstronomical Optics: Design, Manufacture, and Test of Space and Ground Systems 2017 - San Diego, United States
Duration: Aug 6 2017Aug 10 2017

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherAstronomical Optics: Design, Manufacture, and Test of Space and Ground Systems 2017
Country/TerritoryUnited States
CitySan Diego


  • Adaptive Optics
  • Circuit Design
  • Fast Steering Mirror
  • Laboratory Education
  • Wavefront Sensor

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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