MEP EP#246: Doing Something Magical

Parker

• Physicists build circuit that generates clean, limitless power from graphene
  • University of Arkansas physicists
  • Energy harvesting the thermal motion of graphene
  • Without getting all quantum about it, it seems to work by configuring the graphene as one electrode (or both) of a capacitor. As the graphene flaps in the breeze (actually Brownian motion, I assume), the changing geometry will change the capacitance.
  • The team's next objective is to determine if the DC current can be stored in a capacitor for later use
  • Youtube video

Stephen

• New test equipment design - picking the right opamp
  • Current sensing with a bit of a twist
  • Powered by +/-12V
  • Need to read current on the +12 and the -12 along with a +9V rail
  • Opamp needs to be capable of reading a voltage drop in an environment where the common mode voltage is at or near the opamp supply voltage
  • Current sense amplifiers
  • INA1x9 series amplifiers from TI
    • Supply and common mode range are independent of each other
    • 2.7v to 60v
  • Convert a voltage to a current then change the gain by selecting an appropriate load
• Iphone 12 doesn’t come with a charger?
  • Are chargers necessary?
  • Don't we have like 300 of them lying around?
  • Apple states environmental reasons for dropping the charger
  • Also no earbuds
  • Examples of other products that lack the equipment necessary to function
    • Video game consoles?
    • Appliances?
    • Internet router?