I'm convinced (in MOST cases) they no longer even test these heat producing devices under real world conditions,
they just buy up the parts according to design drafts and wack them in (or wrist burn OHL assemblers to do it cheaper than cheap),
without even a quick pre test of the safety components before fitting,
LOL even if they are 'Never Trip' values to begin with
You would think the bosses and staff might take some prototype units home for some weekend project soldering,
put them through the paces and report back before release,
as well as sneak in a SUGGESTION to add in cheap fuses as CHEAP INSURANCE!
It's dumbass at best and or manufacturer foot shooting
FWIW rumour suggests a LOT of these companies are now ~owned~ by electronics challenged CLUELESS shyster investment groups
that either don't employ and or suppress proper EE SAFETY recommendations,
perhaps fudge the UL thing,
then release their corpotrolls on the inernet to do damage control dirty work
That used to sort of work back in 2000 AD, but it's like 2019 now and people are a bit more internet savvy,
well, not by much, just a bit more than not at all...
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So folks, do ya reckon the corpotrolls will throw in the dirty towel and report back to the bosses to fit some fusing in the suckers
before dwindling reputation and sales begin to go seriously south?