summer near over

misc/battery_powered_equipment_is_good

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+
+simple, simple, simple
+battery powered, battery powered, battery powered.
+keep a watch on battery powered test equipment.
+always nice to have. can wrench on the car with these.

misc/limit_switches_and_estop_switches

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+limit switches, also EStop switches (emergency) should
+always activate low, idle high. it must idle high, because
+consider what would happen if it idles low, then the wire
+gets inadvertedly disconnected. you wouldn't notice it. 
+BUT, you can also just put all estops on an actual hardware
+disconnect for best practice. At the risk of frying some 
+not robust chips (tradeoff). Though the note for limit switches
+remains correct.

misc/pcb_panels_for_enclosures_and_racks

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+i knew for a while about making a pcb front panel for a case. 
+i did this on the flammable gas sensor. however, i didn't think
+that it's also practical to make a pcb front panel for custom rack
+mounted hardware, like in a server rack. That is fancy. why not?
+
+https://www.eevblog.com/forum/projects/trying-to-make-affordable-metal-case-for-custom-pcb/msg1315739/#msg1315739
+
+says that the pcbs wouldn't be able to handle the stress of holding
+onto the rack at the sides. fair enough, but it should still be possible
+to use metal for the sides, and then a separate front panel that is a pcb.
+apparently this isn't common practice, looking at enclosures, e.g.
+https://www.circuitspecialists.com/collections/rackmount-enclosures
+but then jlcpcb only came about recently, so i can understand why large
+front panel pcbs weren't used in the 90's or early 2000's.
+Now, it would be cheap to do.
+couple years ago, making this affordable only recently. 
+
+more good ideas
+https://www.eevblog.com/forum/manufacture/how-do-you-house-larger-than-average-home-projects/msg3351036/#msg3351036

misc/star_grounding_vs_daisy_chain

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+
+"NB Never daisy-chain earth wiring: Wire all the Earths back to a
+central connection (Star-grounding), which is connected to Mains
+Earth - this also serves to protect you in case of an electrical
+leakage / short"
+This is good. I've heard about the star ground, but never heard
+what not to do such as: daisy chain grounds. That is no good. One thing to
+avoid.
+
+https://electronics.stackexchange.com/questions/643007/understanding-why-daisy-chaining-causes-ground-loops-in-this-setup
+
+has an explanation, though I don't really need one.
+
+Is there another ground type besides daisy chain / star grounding...?
+
+There's this but it's not well written.
+https://eepower.com/technical-articles/single-point-and-multi-point-signal-grounding/
+
+

misc/ti_powersupply_topologies_book_notes

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+per amp hour 494
+took a quick look at it.
+
+doesn't have much background about the topologies
+it does however have waveforms, which while being
+unusual, is actually quite useful