156B Week 7

Overview of Status of Analysis, Design, Fabrication, Tests, etc.

• • Temperature controller improved; huge overshoot from integral action mitigated

• Awaiting remaining purchased components for RTD circuit and filter circuit

  • current source, regulating PWM module, H-bridge module

  • Armband prototype in production

Accomplishments from Previous Week

• • Decided on (single-sided) thermal tape to cover controlled side of TED

  • Temperature controller improved

    • Overshoot reduced from 10 degrees to ~3 degrees (Celsius)

    • Steady-state error 1-1.5 degrees

  • Adjusted code for powering RTD circuit

  • Purchased regulating pulse width modulator and h-bridge module

  • Verified PWM signal being sent to TED is as expected using oscilloscope

Goals for Next Week (list names after each item). Use specific and measurable objectives.

• • Make final decision on op amp, current source, and voltage reference components for RTD circuit (Justin)

  • Purchase circuit components for RTD circuit and thermal tape(Tom)

  • Assemble and test RTD circuit+code (Tom)

  • Debug how to get data out from oscilloscope (Kam)

  • Test control with Dr. Chen's TED (Kam)

  • Figure out circuit wiring for regulating pulse width modulator and h-bridge module (Jeffrey)

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)

• • Confirmed with sponsor that a 3 degree overshoot is acceptable, but lower would be preferable (5/10, via email)

Instructor Comments from Last Meeting and Actions Taken to Address these Comments  (indicate date of comments and if via email or in person)

• • Use 4 wire RTD configuration by soldering two additional wires onto the two leads (5/4/20, via zoom)

    • use two op amps and 4.096 V voltage reference (5/10/20, via email)

  • Thermal conductivity is key for TED-skin interface (5/4/20, via zoom)

    • cloth cannot keep moisture away

    • sweat is a good conductor

Comments from Other Students in the Class (indicate date of comments and if via email or in person)

• • None

Risks and Areas of Concern

• • Having some issues getting data (i.e. .csv files) out from oscilloscope (borrowed from Prof. Tustaniwskyj) using our SD card

    • May be due to our SD card being over 2 GB

Resources or Information Required but not Available

• • None

Schedule

• • Test on Dr. Chen's TED

  • Fabricate armband with device integrated

Budget (list amount spent and amount remaining)

• • Spent: $438

  • Remaining: $1561

Progress on Report and Webpage

• • Incorporated some changes from instructor/TA feedback into report