RFID AC SWITCH Mid-Semester Presentation February 21, 2008

Team Members Ricardo Calderon Electrical Engineering Team Leader Research and Documentation RFID Reader PIC Programming Website Design Jonathan Stanley Electrical Engineering Research and Documentation Power Supply TRIAC Control Website Design Jerome Walker Computer Engineering Research and Documentation PIC Programming Website Design Corey Tate Electrical Engineering Research and Documentation Power Supply TRIAC Control

Overview Introduction Problem Solution Technical Constraints Practical Constraints Design Approach Timeline & Current Progress References Questions

Introduction What is RFID? How can RFID technology be used? –Inventory Control –Personal Access

Problem There are no RFID AC Switches. Many people are unfamiliar with the capability RFID Technology.

Solution OEM RFID AC Switch This will give manufacturers a quicker time to market.

Implementations How can the RFID AC Switch be used? –Light Control –Security Access –Outlet Control

Technical Constraints NameDescription Switching VoltageMust operate at 120 VAC. Output CurrentMust have a maximum current of 15 amperes. Read DistanceMust have a read distance of 2” to 5”. Authorized Tag Identification Must read 125kHz tags. Tag QuantityMust store at least 200 identification tags.

Practical Constraints TypeNameDescription ManufacturabilitySizeMust have dimensions of at most 4” in length, 4” in width, and 2” in depth. Health and SafetySafetyMust meet UL (Underwriters Laboratories) guidelines.

Practical Constraints-Size RFID AC Switch must have dimensions of at most 4” in length, 4” in width, and 2” in depth Why? –Adaptability

Practical Constraints-Safety RFID AC Switch must meet UL (Underwriters Laboratories) guidelines How to meet these guidelines? –Proper Enclosure –Isolated Connections –Overcurrent Protection

Power Supply RFID ReaderMicrocontroller Switch Design Approach 5VDC Tag Information 0 or 5VDC 120 VAC Device 0 or 120VAC

Power Supply Transformer [1] RC Circuit [2] AC/DC Converter [3]

Power Supply MethodsAdvantagesDisadvantages TransformerProven design Drop high voltages Bulky size RC CircuitSimple design Inexpensive Low output current Heat dissipation AC/DC ConverterCompact design Sufficient current Complex circuit

RFID Reader ID-12 Reader [4] Core ID-20 Reader [5] Parallax Reader [6]

RFID Reader MethodsAdvantagesDisadvantages Innovations ID-12Compact size Sufficient read range Does not read multiple tags at once Parallax RFID Reader Simple set-upBulky size Short read range Core ID-20Compact size Sufficient read range Availability

Microcontroller PIC 18f2420 [7] PIC18F2420 chosen for Microcontroller

Switch MethodsAdvantagesDisadvantages TRIACCompact size Simple Implementation Heat dissipation RelayLow heat dissipationBulky size Costly TRIAC [9] Relay [10]

Timeline JanuaryFebruaryMarchApril Power Supply TRIAC RFID Program PIC Testing

Current Progress-Power Supply Power Supply CircuitPower Supply Circuit Output Voltage 5VDC

Current Progress-TRIAC TRIAC Circuit 0VDC Sent to Gate TRIAC Output 0VAC 0VAC Output Wave

Current Progress-TRIAC 5VDC Sent to Gate 120VAC TRIAC Output 120VAC, 60Hz Output Wave

Current Progress-RFID Reader LED on when tag Present ID-12 Reader RFID Tag RFID Tag Code on Hyperterminal

References [1] “Photo of Power Transformer,” February 18, [Online.] Available: [2] “Photo of Capacitive Transformerless AC to DC Power Supply, with common Hot,” Transformerless AC to DC power Supply, February 18, [Online.] Available: Supplies.phtml Supplies.phtml [3] “Photo of AC/DC Converter,” ROHM, February 18, [Online.] Available: [4] “Photo of Innovations ID-12,” ID Innovations, February 18, [Online.] Available: [5] “Photo of Core-20,” Core-20 RFID Reader Module, February 18, [Online.] Available: [6] “Photo of Parallax Reader,” Parallax Inc., February 18, [Online.] Available: List/1/ProductID/114/Default.aspx?SortField=ProductName%2cProductName

References [7] “Photo of PIC18f2420,” Microchip, February 18, [Online.] Available: [8] “Photo of Basic Stamp,” Basic Stamp 2 Module, February 18, [Online.] Available: 0/SortField/0/Level/a/ProductID/1/Default.aspx 0/SortField/0/Level/a/ProductID/1/Default.aspx [9] “Photo of TRIAC,” February 18, [Online.] Available: [10] “Photo of Relay,” February 18, [Online.] Available: [11]“Photo of Question Mark,” February 18, [Online.] Available:

Questions Questions?? [11]