SlideServe
Télécharger Obtenir Pro
Menu
Accueil Pro
Préférences
ApparenceLight Aide et commentaires
© SlideServe · v2026

Reliability and Safety Analysis

isleen avatar
isleen
12 diapositives · 440 Views · Jul 10, 2014

Reliability and Safety Analysis. Team 4: Shicheng Guo , Kyle Haver , Ethan Price, Wesley Tso. Overview. Device that automatically roasts coffee beans based on a roast level selected by user via GUI. Device uses base popcorn popper, as well as a variety of sensors, to achieve automation.

Reliability and Safety Analysis - slide 1
01 / 12Reliability and Safety Analysis
1 / 17

Télécharger la présentation

Reliability and Safety Analysis
Une image / un lien ci-dessous est fourni (tel quel) pour télécharger la présentation

Politique de téléchargement : le contenu du site vous est fourni TEL QUEL pour votre information et votre usage personnel ; il ne peut être vendu, concédé sous licence ni partagé sur d’autres sites sans l’accord de son auteur.Le contenu vous est fourni TEL QUEL, pour votre information et votre usage personnel uniquement. Téléchargez la présentation en cliquant sur ce lien. Lors du téléchargement, si vous ne parvenez pas à télécharger une présentation, l’éditeur a peut-être supprimé le fichier de son serveur.Pendant le téléchargement, si vous ne parvenez pas à obtenir une présentation, le fichier a peut-être été supprimé par l’éditeur.

F I N

Plus de contenu associé

Transcription de la présentation

  1. Reliability and Safety Analysis Team 4: ShichengGuo, Kyle Haver, Ethan Price, Wesley Tso

  2. Overview • Device that automatically roasts coffee beans based on a roast level selected by user via GUI. • Device uses base popcorn popper, as well as a variety of sensors, to achieve automation. • Safety is a major concern due to high power usage and heat generated by device being the main possible causes of critical failures.

  3. PSSCs • An ability to achieve different levels of roasting based on user input. • An ability to detect the temperature of the beans. • An ability to monitor the color of the beans • An ability to interact with the user via GUI • An ability to shut off the device if unusual conditions (dangerously high temperatures, unusual color in roasting area, or timeout) are detected.

  4. Components Chosen • Components listed in order of “closeness” to power and heat of device. • AC Relay (ST24D12): controls heating coil. • DC Relay (LCA717S): controls cooling fans and rotates beans. • Microprocessor (ATMEGA8A-AU): controls overall operation, including the relays and safety checks. • Voltage Regulator (LM7805CT): regulates power to microprocessor, therefore indirectly affecting relays. • Transformer (273-1512): supplies power to microprocessor circuit, including voltage regulator, relays, voltage regulator, and microprocessor.

  5. AC Relay • λp = λb * πQ * πE Failures/10^6 hours. • λp = 1.6 Failures/10^6 hours.

  6. DC Relay • λp = λb * πQ * πE Failures/10^6 hours. • λp = 1.6 Failures/10^6 hours.

  7. Microprocessor • λp = (C1 * π T + C2 * π E) * xQ * xL Failures/10^6 hours. • λp = 0.2818 Failures/10^6 hours.

  8. Voltage Regulator • λp = λb * πT * πS * πC * πQ * πEFailures/10^6 hours. • λp = 0.02448 Failures/10^6 hours.

  9. Transformer • λp = λb * πQ * πE Failures/10^6 hours. • λp = 0.057 Failures/10^6 hours.

  10. Other Components • Sensors (Microphone, Camera, Thermometer) • Rotary Encoder • LED • Display

  11. Summary • Most prone to critical failures are the relays. • Possible design alternatives: • Have two relays ORed together for each current relay. For AC Relay, OR for off functionality. For DC relay, OR for on functionality. • Spend way more money on higher grade relays. • Neither are very appealing.

  12. Links • AC Relay Data Sheet: http://www.teledynerelays.com/pdf/industrial/st.pdf • DC Relay Data Sheet: http://www.clare.com/home/pdfs.nsf/www/LCA717.pdf/$file/LCA717.pdf • Microprocessor Web Link: http://www.atmel.com/devices/atmega168a.aspx • Voltage Regulator Data Sheet: http://www.fairchildsemi.com/ds/LM/LM7805.pdf • Transformer Web Link: http://www.radioshack.com/product/index.jsp?productId=2102703