184_projects:design_defib_24

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Your team was able to shut down the hawkion accelerator before it could blow itself up, and possibly take Lakeview with it. But the beam dump that absorbed the hawkions is now highly radioactive. You need to put shielding around it before anyone receives too high of a dose, but no one can go near it.

Solomon Tobb, the ingenious intern, suggests that project I.A.N. could save the day.

The Artemis 13 is on it's way back to Earth and currently is hanging in lower Earth orbit. You and a team of scientists have been desperately re-wiring the spacecraft circuitry to get home. While soldering wires, your android co-pilot Johnny 5 begins to malfunction, it is essential that Johnny 5 not lose all power as he controls the landing sequence to reach the planet's surface. Melissa Lewis, the team leader, mentioned that in a training video she saw back in the 80's call “Short Circuit 2” a model like Johnny 5 was brought back to life using a defibrillator.

You run to the medical bay and grab the defibrillator and rush back to Johnny 5. When you go to charge the defibrillator, however, you notice that the instruments are not reporting a proper charge. In order to not risk the safety of Johnny 5 by shocking him with faulty equipment, you decide against pressing the button and shouting “clear.” You need to save Johnny 5. Using your knowledge of electromagnetism, you know you can create a makeshift piece of equipment to be able to stabilize Johnny 5.

You run to the limited “stock room” on board, only to discover limited supplies. You manage to find sheets of aluminum, and various paper sheets, some electrical tape and wires, and a pair of all-purpose scissors.

The defibrillator must be able to deliver 360 J to Johnny 5 in order to stabilize him. Can you fix the instrument and save him?

The paper sheets are 0.5 m wide, 2 m in length, and vary in thickness (2 mm, 1 mm, 500 $\mu$m, 50 $\mu$m, 1 $\mu$m, 0.5 $\mu$m). The aluminum sheets are 0.80 m in length, 0.5 m wide, and 0.3 mm in thickness. The defibrillator has a high voltage power supply of 30 kV.

Learning Goals/Conceptual Questions

  1. Explain why you would want to use a capacitor for a defibrillator? Why would you not just connect the paddles to a battery?
  2. Explain how a capacitor charges and discharges.
  3. Explain why you would add a resistor to charging/discharging capacitor circuit.
  4. Draw the circuit diagram for charging the capacitor. Draw the circuit diagram for discharging the capacitor. Can you draw a single circuit diagram for both charging and discharging using a switch? Where is Johnny 5 in the circuit?
  5. Draw V vs t, Q vs t, and I vs t graphs for both charging and discharging circuits.
  6. Explain what the difference is between a capacitor that is “initially connected” versus one that has been hooked up for “a long time”
  7. Calculate the dimensions/size needed to build a capacitor with the desired capacitance.
  8. Summarize equations that we know for both resistors and now capacitors.
  9. Explain what changes about your capacitor when you have a dielectric
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  • Last modified: 2024/01/29 18:27
  • by tdeyoung