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Showing content with the highest reputation on 03/24/2022 in all areas

  1. Finally decided to just go buy the Shop Fox sander at the local place and was surprised to find it over $100 less than the Amazon price. #Winning
    3 points
  2. Clique Patricia Barber 2021 https://album.link/i/1572975046 Example:
    2 points
  3. Went on a Sanguine Hum binge. Example:
    2 points
  4. In a previous post I mentioned the less-than-ideal performance when Carbon is powered by a ±400V supply, and I suspected that the lower Vce on the PZTA42 is the culprit. Now it's been proven. The PZTA42 being a high voltage transistor, has a non-linear region at low Vce, as the slanted curves you can see on the upper left side. With 407V on the negative rail, the transistors on my board works at Vce=8.4V and Ic=20mA, right around the knee. The global negative feedback would have a hard time correcting that non-linearity. It also explains why some people prefer setting the Carbon at a lower current when powered with ±400V supply, as it also improves the linearity of the PZTA42, albeit to a lesser degree. I guess Kevin chose the high voltage PZTA42 to deal with the power-on transients. I have a quick and dirty fix. Just bias the SiC MOSFET a little higher to give the PZTA42 more headroom. The SiC MOSFETs are biased by two 175k and an 20k at the gate. Reducing either 175k or increasing the 20k would do. The goal is to move the PZTA42 operating point to the right, well into the constant-current region (parallel lines). I would use Vce=14 to 15V. Pushing it even higher would increase the power dissipation on the PZTA42, eat into the max output voltage swing and have diminishing return. What I did was to put a 260k resistor in parallel with one of the 175k resistors. YMMV because it has to do with the operating point of the PZTA42 in your circuit, the Vgs(th) of your SiC MOSFET, etc. After the quick fix, one of the channels now measures as good as with the ±450V supply. We can see that the max output voltage is slightly less compared to with ±450V supply. The difference is subtle with the log scale, though. Now I'm continue to work on the other channel and see if I can find something else.
    2 points
  5. I’ve never been able to shake the habit of subvocalization so I’ve been stuck with the same narrator for every book I’ve read. 🙃
    1 point
  6. Bobiverse & Project Hail Mary = same narrator (Ray Porter).
    1 point
  7. Talk about out of the frying pan and into the fire...
    1 point
  8. I didn't know that JH13s were speakers.
    1 point
  9. My mother's maiden name is Styants, which is pretty unusual (like Samost). Because it is so strange it is easy to trace back. I've got as far as the late 1600's, but its root is the Anglo-Saxon Stigand. In fact the Archbishop of Canterbury in 1066 when William of Normandy invaded was called Stigand. But clergy back then would commonly take a wife or two, and/or other women, so who knows - I might date back to a very naughty Archbishop 960 years ago.
    1 point
  10. Me 3.....my last name, Samost, is quite unique. I have been called Samos (and there is a cabinet-maker family near me with that name), or Samoset like the Native American Tribe. When we first moved in our neighborhood, someone told me they were excited because they (didn't fully catch my name and) thought I may be related to John Stamos 😊 On the other hand, I love having this unique of a name. Pretty sure that anyone with that last name in the USA is a blood or marriage relative.
    1 point
  11. Turkey: 'Missing' man joins search party looking for himself
    1 point
  12. also "This Morning, Russian Phosphorus Bombs Were Used": Zelensky To NATO.
    0 points
  13. RIP to Stephen Wilhite, the dude who created the GIF format.
    0 points
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