Digital Real-Time Intelligent Time Networked Kegerator

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Dustin Poe Justin Thacker Ian Snyder Matt Kocsis

• Digital Real-Time Intelligent Time Networked
  Kegerator

Reliability and Safety Analysis
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Common Beverage Interface
Function Common beverage interface Common beverage interface Common beverage interface      
Failure no Failure Mode Possible Cause Failure Effects Method of detection Criticality Probability
A1 No Beverage Monitoring Flow meters,Optocouplers (J74) XOR (J53)R40-R43 Inaccurate or Failure to Monitor BAC Software, Observation on LCD High 5.99E-08
A2 Solenoids won't open Solenoids, MOSFETS (Q1, Q2, Q3, Q4)diodes (D14, D15, D11, D9), wire J56, J55, J44 J46 Inability to dispense beverage Observation, Med 1.71E-06
A3 Solenoids won't close Solenoids, MOSFETS (Q1, Q2, Q3, Q4)diodes (D14, D15, D11, D9), optocouplers, wire Inability to control beverage flow Observation, Med 1.71E-06
A4 KEG Showing Not connected connector, wire, R15, Inability to serve all beverages Observation, Low 9.26E-07
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Temperature Control Interface
Most Dangerous Failure Mode Contactor
Continuously Driven High
Failure no Failure Mode Possible Cause Failure Effects Method of detection Criticality Probability
C1 Improper or No Temperature Monitoring Temperature Probes, R31, Connector, Wire Inaccurate Temperature Regulation, Compressor Failure, Overheating Software, Observation on LCD Med TBD 
C2 Contactor Driven Constant High Contacts on relay melded shut, MOSFET Failure Q5, J57 Compressor Failure, Overheating Observation, Very High  TBD
C3 Contactor Driven Constant Low Relay Failure, MOSFET, Q5, J57 Inability to Cool Beverage, Observation, Med TBD 
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3.3V Switching Power Supply
Function 3.3V Power Circuit 3.3V Power Circuit 3.3V Power Circuit      
Failure no Failure Mode Possible Cause Failure Effects Method of detection Criticality Probability
E1 Voltage Output gt3.3 External PS, J26,D2 Unpredicted Behavior and potential damage to led and Microprocessor Observation, High TBD 
E2 Voltage Output0 Any component in Block D, Power and Ground Short Loss of Serial Communications, RFID, ability to monitor temp and flow Observation, High TBD 
E3 Out of Tolerance Any component is Block D Out of Spec Operating Voltage Observation, High TBD 
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5V Switching Power Supply
Function 5V Power Circuit 5V Power Circuit 5V Power Circuit        
Failure no Failure Mode Possible Cause Failure Effects Failure Effects Method of detection Criticality Probability
D1 Voltage Output gt5V External PS, J30,D3 Unpredicted Behavior and potential damage to Serial Communications, RFID, ability to monitor temp and flow, potential to damage Micro Unpredicted Behavior and potential damage to Serial Communications, RFID, ability to monitor temp and flow, potential to damage Micro Observation, High TBD  
D2 Voltage Output0 Any component in Block D Loss of RFID, and Biometric, ability to monitor temp and flow Loss of RFID, and Biometric, ability to monitor temp and flow Observation, Very High TBD  
D3 Out of Tolerance Any component is Block D Out of Spec Operating Voltage Out of Spec Operating Voltage Observation, High TBD  
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Rotary Pulse Generator and LCD
Function RPG and LCD RPG and LCD RPG and LCD      
Failure no Failure Mode Possible Cause Failure Effects Method of detection Criticality Probability
B1 Rotary Pulse Generator failure RPG, wire, header, R9, R14 Inability to Navigate through menu Observation on LCD Med TBD 
B2 LCD Improper Display Wire, Header, Noise Inability to see Menu Observation on LCD Med TBD
B3 LCD Failure J42, connector, wire Inability to See Menu Observation on LCD High TBD  
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User Identification Interface
Function RFID, and Biometrics RFID, and Biometrics RFID, and Biometrics      
Failure no Failure Mode Possible Cause Failure Effects Method of detection Criticality Probability
F2 Failure of RFID Antenna, RFID chip(J51), Level Translator J75 Unable to Identify cup size cannot limit flow Observation, Software Med TBD 
F4 Failure of Biometric Thumb Print Reader, RS232 level translator (J43) Inability to Identify Users, therefore inability to monitor Observation, High TBD  
F1 Invalid RFID Match Antenna, RFID chip(J51), Level Translator J75, RFID Transponder Incorrect identification of cup size and incorrect flow limit Observation, Software High TBD
F3 Invalid Finger Match Thumb Print Reader, RS232 level translator (J43) Incorrect identification of users, unauthorized pours Observation, Software High TBD
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Currency Acceptor Interface
System Digital Real-time Intelligent Networked Kegerator Digital Real-time Intelligent Networked Kegerator        
Function Currency Acceptor Currency Acceptor Currency Acceptor      
Failure no Failure Mode Possible Cause Failure Effects Method of detection Criticality Probability
F1 Dollar Bill Acceptor Fails Off RS-232 Cable, J42, Dollar Bill Acceptor Inability to Buy Credits for Drinks Observation, Med/High  TBD
F2 Dollar Bill Acceptor Fails On RS-232 Cable, J42, Dollar Bill Acceptor Accepts Dollars/but doesn't give credits Observation, High TBD