Clipping and Clamping OpAmps

May 20, 2020 Hosted by Parker Dillmann, Stephen Kraig

Are rules of thumb obsolete? Validate your thumbs on this episode of the MacroFab Engineering Podcast while Parker discusses progress on the brewery!

Stephen

  • DC heaters continued
    • Tested the new values
    • Last episode was shooting for ~250mW of dissipation in the regulator and transistor
    • Measuring closer to 350mW
      • Quiescent current and some balancing and tolerance
  • Opamp clamping circuit
    • A useful voltage clamping circuit with independent upper and lower thresholds
    • Pros
      • Much more accurate than the simple clipping circuits
      • Hard turn on characteristics
      • Can be overdriven without much issues
      • Not terribly expensive
    • Downsides
      • 3 or 4 opamps needed
      • Not particularly fast – starts to show issues past 20k and is pretty bad at 30k
      • Small overshoot that is frequency dependent
      • Does not work with opamps that have input protection diodes

Parker

  • Brewery Updates!
    •  Installed
      • Tubing
      • Pumps
      • Pots
    • Waiting on
      • Stainless mesh basket
    • What is left
      • Design and build the grain crane
      • Mount electrical box
      • Finish wiring
      • Paint and sealant
    • Electrical Box
      • Might have put the power input in the wrong spot!
      • Need to finish the wiring.. Need to order more wire I think…

R.F.O.

  • Rules of thumb – Are they obsolete? 
  • Next week we have Al Williams on from Hack a Day
    • If anyone has any questions for him let us know in slack!

Hosts: Parker Dillmann, Stephen Kraig

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