Programmable Power Relay Senior Design II Midterm Presentation

Team Members Jameson Mitchell  Electrical Engineering  PC to PIC communication  GUI Design David Null  Electrical Engineering  TRIAC control  Firmware Design  Research and Documentation  Schematic Design  PCB Layout Rick Wolbrecht  Electrical Engineering  Packet Encoding  GUI Design Lane Simmons  Electrical Engineering  Team Leader  Firmware Design  Website Design  Research and Documentation

Overview Introduction Problem Solution Practical Constraints Technical Constraints Senior Design II Additions Test Plan Schematic Future Plans

Introduction What’s the PPR supposed to do? Control device power using schedule Allow automated control Minimize need for user input after schedule is set +

Problem Current power strips have few features  No programmable timing schedule  No interactive user interface  No dimming capability  Few methods to exercise schedule control over electronic devices.  Unable to control power when away from device

Solution "Smart" power strip with enhanced features o Programmable Timing Schedule for AC-switching o PC software application Possible Target Markets Automation Security

Practical Constraints

Health and Safety Must conform to Underwriters Laboratories (UL) standards for safety o Non-conducive Casing o Fused Overcurrent Protection

Economic Must be manufactured for less than $50

Technical Constraints Real time clock must operate at all times, under all power conditions Timing schedule accuracy must include Years, Months, Days, Hours, Minutes, Seconds PC is required to operate user interface Must supply power to internals from 120VAC Switching power must operate up to 120VAC at 15A (NEMA 5-15 Standard) [1] Must support output dimming

Technical Constraints Results From Design I RTCC OperationPass Timing Schedule AccuracyPass PC OperationPass AC/DC Power SupplyPass Power OutputPass Output DimmingFail

Technical Constraints Results in Design II RTCC OperationPass Timing Schedule AccuracyPass PC OperationPass AC/DC Power SupplyPass Power OutputPass Output DimmingPass

Senior Design II Additions Independent second output Support for event repeats Support for event deletes through the PC interface Output Dimming

Test Plan PC Exception Handling Additional Power Output Event Repeats Output Dimming

Software Improvements in SD2 Fixed Text File I/O problems Error-checking in GUI interface Added Ability to View Scheduled Events

Error Checking

GUI Updates

Additional Power Output

Hardware  Triac  Optoisolator Firmware  Sorting Algorithm

Additional Power Output Test Results

Event Repeats Old sorting algorithm ignored expired events New sorting algorithm recognizes repeat flags in expired events and skips the event to the correct RTCC comparison.

Event Repeat Example

Event Repeat Test

Output Dimming Improvements Interrupt driven Triac pulsing

Output Dimming Tests

Eagle Schematic

PCB Layout

Future Work PCB Order Parts for PCB Populate board Order an Enclosure Event Deletes in Software

Questions ?

References [1] Powercords Online, "IDC Plugs - Standards," [Online]. Availible [2] "Appliance Wiring Material, UL 758." Underwriters Laboratories. Accessed September 16, [3] “Isolé® IDP-3050 Plug Load Control.” WattStopper. &type=Commercial. Accessed August 27, &type=Commercial [4] “Bits Energy Saving Smart Strips.” Bits Limited. Accessed August 27, [5] “6-PIN Dip Random Phase Optoisolators Triac Driver Output.” Programmable Power Relay Datasheets. M.pdf. Accessed December 1, M.pdf