Drew an Ero furcata (two-humped pirate spider) to celebrate it being awarded Spider of the Year 2021!
It appears that the popular Riden/Ruideng/RD Tech DP/DPS/DPH series power supplies use low-side current sensing, which can lead to some unexpected (and potentially destructive) behaviour in a situation where you have multiple unisolated power rails.
For example, I put together a little box with a DP30V5A providing a variable, current-limited rail, and three LM2595 modules providing fixed 12v, 5v and 3.3v rails. As none of these supplies are isolated, and can therefore not be used to provide negative rails, I tied all their 0V outputs together. This led to the DP30V5A reporting a completely false current consumption of about 33% of the measured value.
After sketching everything out, it became obvious that this was due to the low-side current sense resistor only seeing some of the current flow, and the rest flowing through the unused LM2596 modules (the switch A represents the internal connection between the DP30V5A 0V and the fixed rail 0V)
Disconnecting the 0V rails and providing a separate 0V binding point for the fixed rails fixed this issue, and I’ll just have to keep in mind that if I want to use multiple rails from this mini PSU in the same circuit, I can’t trust the DP30V5A current reading and have to set its maximum current to about 33% of the desired value. Otherwise, the software overcurrent protection can’t function correctly, and there’s a risk of damaging both the module and the circut under test.
An amusing side effect of this setup is that the DP30V5A low side current sensing can be used for the fixed rails! I doubt I’ll ever encounter a situation where this is useful though.
More about high and low side current sensing in this AAC article
Another breakthrough in the increasingly relevant field of linguistic cryptozoology
(previously: most weasel)
That first one was definitely the funniest, but the some of the other bowl-demons are pretty great too.
There’s a bit more detail about exactly what’s going on in this article.
I’m surprised how timeless and appealing these little drawings are. They avoid a lot of the foibles which make a lot of late antique/medieval art look dated, and the exaggerated proportions, noodly limbs and googly eyes wouldn’t be out of place in a webcomic or cartoon.
I also love that these bowls refer to themselves as “amulets”. Next time someone describes something as an “amulet” in a novel or TTRPG I’m definitely going to imagine it as an inverted bowl with a googly-eyed stick figure demon on.
Recently found this fun local Austrian legend about @apocrypals’ favourite 12 foot tall werewolf saint.
#TIL that VLC player has a built in compressor, in Window → Audio Effects, of all places. A boon for poorly mixed podcast listening!
Feedback appreciated, either as replies, GH issues, or at indieweb.org/discuss
Extremely cursed UI at neverwinter.fandom.com/wiki/Ring_of_Warding
PHPUnit’s HTML code coverage reports don’t play nicely with GitHub pages “main branch /docs folder” by default, as they store CSS, JS and icon assets in folders prefixed with underscores.
Here’s a little bash script to run tests with code coverage enabled, then move the assets around:
rm -rf docs/coverage/ XDEBUG_MODE=coverage ./vendor/bin/phpunit tests --coverage-filter src --coverage-html docs/coverage mv docs/coverage/_css docs/coverage/phpunit_css mv docs/coverage/_icons docs/coverage/phpunit_icons mv docs/coverage/_js docs/coverage/phpunit_js grep -rl _css docs/coverage | xargs sed -i "" -e 's/_css/phpunit_css/g' grep -rl _icons docs/coverage | xargs sed -i "" -e 's/_icons/phpunit_icons/g' grep -rl _js docs/coverage | xargs sed -i "" -e 's/_js/phpunit_js/g'
That allows you to use GitHub pages to show code coverage reports as well as docs, as I’m doing for taproot/indieauth.
Some more hamster activity today! Anyone have any idea what the behaviour at 0:57 is? Looks like it’s trying to flatten grass, but I imagine it’d rather rest in its hole than on the surface.
If the micrometer is to be believed, these maple shavings are 0.015mm thick. Amazing what’s possible with sharp tools!