Electronic Manufacturing, electronics podcast, Garage Door Opener Hack, High voltage low current measurement, MacroFab, macrofab engineering podcast, PyInstaller, Transformers

MEP EP#239: Frictionless Spherical Cow Transformers

Podcast Notes


  • Garage Door opener hacking
    • Converting my normal style garage door opener to a “jackshaft” style opener
    • Reversing the direction of the A/C single phase motor?
      • Split phase motors
      • One phase is shifted with a large capacitor by ~90 degrees
      • In my application I just had to reverse the wires and the end stop wires
  • PyInstaller
    • Can take your python scripts and make it into a self contained application
    • Useful for non technical inclined people on your team
    • Cross Platform!
    • GUIs
      • Tkinter seems to work well in Win10 and Ubuntu 20 LTS


  • High voltage low current measurement
    • Tony_W Recommended the ACS37002
      • Hall effect sensor that can be ground referenced in very high voltage applications   
      • 0.85m ohm conductor resistance
      • 4.8kV RMS isolation voltage
      • VCC of up to 6.5V
      • -50 to 50A sensing range
      • Gain selection of 30mv/A to 60mV/A
    • In my situation I would want to monitor 0.1mA or 100uA. With a gain of 60mV/A that would be 60uV/mA so 0.1mA would be 6uV….. This may still not be the best solution because I would likely need a ton of gain and have to correct for any offsets.
    • Possibly to a tro prong approach – Measure voltage across known resistances in the circuit
  • Getting transformers manufactured for your product
    • What do you need to know?
    • How do you get started?
    • What are the specifications
      • Mains transformers
      • SMPS and flyback style “yellow tape” Transformers.


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