Electronic Manufacturing, electronics podcast, MacroFab, macrofab engineering podcast

MEP EP#246: Doing Something Magical

Podcast Notes


  • 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


  • 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?

Special thanks to whixr over at Tymkrs for the intro and outro!