StuMichaels

's profile
image
Embedded Engineer

Semi-retired; doing some consulting


StuMichaels

's contributions
  • 06.12.2017
  • Embedded resistance measurement
  • It seems to me to be a very complicated way of doing something simple. If you connect the low side of R3 to the inverting input of an op amp and the right side of R2 to the op amp's output, then whatever current enters R1 goes out R2 and R3 has no effect on the current. Of course, you must use an op amp with a low bias current so the voltage across R3 is negligible. If the low side of R3 is truly grounded, it won't matter if you use floating instruments and batteries for the power supplies, that is positive and negative supplies. It can be done with a single supply but it gets a little more complicated.
  • 05.28.2016
  • Old faithful tools
  • I still sometimes use my Weller Junior soldering gun I got when I was about 15. That was about 58 years, ago. I also have a Simpson 260 VOM although I never use it. Ditto for my Eico scope. Somewhat newer are two HP signal sources, one is a sine wave generator and the other is a pulse generator. I'm sure if I carefully looked around my basement, I could find more old equipment, some of which I sometimes use while the rest gathers dust.
  • 11.02.2014
  • Sine Tips
  • I just checked; I last programmed in GW Basic 22 years ago!!!
  • 11.02.2014
  • Sine Tips
  • GW Basic? You're kidding! I haven't used GW Basic for at least 10 years.
  • 10.20.2014
  • Load switch with self-resetting circuit breaker
  • Do not use this circuit with inductive loads as the rapid current turn off will cause a large voltage spike which can destroy Q2. Either add a snubber at Q2's drain or modify the circuit to cause Q2 to turn off slowly.
  • 04.23.2014
  • Automotive automation: Too much, or not enough?
  • Will cars actually be safer with the driver out of the equation? I don't like the idea of giving up control to possibly flaky software (Toyota unintended acceleration) or flaky hardware (GM ignition switch). I had a BMW whose software could not cope with an incorrect wiring harness replaced by the dealer.