MEP EP#225: Clipping and Clamping OpAmps

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!