Download Built-In Test Software for Deformable Mirror High Voltage

Built-In Test Software for Deformable Mirror High Voltage Drivers
Jianwei Zhou
Home Institution: University of Hawaii at Manoa
CfAO Akaimai Internship 2008
Subaru Telescope
Mentor: Stephen Colley
Funding provided by the Center for Adaptive Optics through its
National Science Foundation Science and Technology Center grant
(#AST-987683)
Today’s Presentation
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Background
Importance of Build-In Test software
Design Process
Conclusion
Acknowledgement
Acronyms
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A/D – Analog to Digital
D/A – Digital to Analog
BIT- Built-In Test
DM- Deformable Mirror
HV – High Voltage
ICD – In-Circuit Debugger
LGSAO – Laser Guide Star Adaptive-Optics
MUX – Multiplexer
Project Overview
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Design Built-In Test (BIT) software for
deformable mirror high voltage driver in the
Subaru LGSAO system.
Measurements performed by BIT circuitry
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Input Voltages
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Output Voltages
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Power Supply Voltages
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Board Temperature
Deformable Mirror (DM)
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DM is used with wavefront sensor to provided optical control and correction.
The DM is divided into 188 segments with separate control voltage to each segment
DM operates with maximum voltages of +400V, and HV amplifiers with gain of 40
are used to amplify input voltages of + 10v to +400v.
HV Driver Subsystem
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The HV driver subsystem in the Subaru LGSAO system
consist of 10 HV Amplifier boards
High Voltage Amplifier Board
Importance of Built-In Test Software
+ 10v
Digital
Real-Time
Control
Computer
Data
D/A
Converter
Board
188
+ 400 v
HV
Amplifier
Board
w/BIT
188
DM
Built-In Test Circuit
Main components:
Analog Multiplexer (Mux)
Analog-To-Digital Converter
Microcontroller (PIC 16F877)
Temperature Sensor
Mux
A/D
Converter
BIT
Circuit
Microcontroller
Temperature
Sensor
Host
Computer
Built-In Test Software
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Program Language use: C
Step 1: Program in C
Step 2: Compile to Assembly language by PICC STD.
Pros and cons
 C is easier and much shorter than assembly language
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Programming requires the knowledge of microcontroller
In-Circuit Debugger
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Real-time debugger and programmer
MPLAB IDE
Memory Constraints of
Microcontroller
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Programs must fit in the available on-chip program
memory ( very small compare to computer)
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Must optimize the code to reduce the memory
Conclusion
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Tested the BIT circuit
1 bad A/D converter is found in one board
Fabrication error of temperature sensor
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BIT software successfully measures the input
voltages, output voltages, and power supply
voltages on a HV amplifier board
Work To Be Completed
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Communication between the BIT circuit and
host computer
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Run the BIT software in the whole LGSAO
system
Personal Thought
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A valuable opportunity to learn about circuit
design
Application of the knowledge learnt in school
to real life practice
Increased research ability
Increased Confidence
Acknowledgements
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Stephen Colley, Mentor
Akamai Internship staff
Sarah Anderson, Hawaii Island Internship Coordinator
Lynne Raschke, Science Communication Lead Instructor
Scott Seagroves, Science Communication Co-instructor
Lisa Hunter, Akamai Internship Director