cat feeder, CNC, Electronic Manufacturing, electronics podcast, MacroFab, macrofab engineering podcast

MEP EP#237: Ice Cream Solder Paste Equipotential

Podcast Notes


  • Cat Feeder Unreminder
    • Started designing the parts and symbols in Eagle. 
    • Will post more on twitter as I build the components and put together the symbols
  • Garage Door opener hacking
    • Converting my normal style garage door opener to a “jackshaft” style opener
    • Why? 
    • LiftMaster, Chamberlain, Craftsmen are all the same 
    • Mine is a Liftmaster Formula 1
      • Belt drive need to convert to chain drive to attach to the jackshaft
      • All of these use similar drive mechs
    • Other things that are needed
      • Garage door auto lock
        • SureLock Garage Door DeadBolt
      • Cable tension switch
        • LiftMaster 41A6104


  • High voltage low current measurement
    • Resistive dividers?
      • Caddock 1776-C681
      • 10M ohm
      • 0.1% tolerance with 0.05% matching
      • Low PPM
      • This method is ok but requires a rather large current sense resistor which is not great.
    • Floating supplies
      • This is how multimeters work. The reference is floating.
    • Isolation solution
      • May go with an isolated solution – basically a power supply that isolates the secondary.
      • Isolated digital communication down to LV side.
  • Tests for pcb shielding
    • Did a shield plane test on a new pcb assembly.
    • Top and bottom pours that respect clearance rules.
    • 5mm pitch via stitching.
    • All terminate to one pin on a 2 pin header.
      • Second pin connects to a plated bolt hole that goes to chassis.



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