"... throughout my house and observed that other than a few large appliances, the majority of powered devices in a typical home in 2026 could be supplied via PoE DC current as well!"
We installed 120 LED ceiling lights in our home circa 2020, all of which were run with high voltage (romex) and accompanied by 120 little transformer boxes that mount inside the ceiling next to them.
Later ...
We installed outdoor lighting with low voltage, outdoor rated wiring and powered by a 12V transformer[1] and I felt the same way you did: why did we use a mile of romex and install all of those little mini transformers when we could have powered the same lights with 12V and low voltage wire ?
I then learned that the energy draw of running the low-volt transformer all the time - especially one large enough to supply an entire house of lighting - would more than cancel out energy savings from powering lower voltage fixtures.
You don't have this problem with outdoor lighting because the entire transformer is on a switch leg and is off most of the time.
So ... I like the idea of removing a lot of unnecessary high voltage wire but it's not as simple as "just put all of your lights behind a transformer".
> I then learned that the energy draw of running the low-volt transformer all the time - especially one large enough to supply an entire house of lighting - would more than cancel out energy savings from powering lower voltage fixtures.
That's not a constraint of physics, you can absolutely build a DC power supply that is efficient in a wide load range. (Worst case it might involve paralleling and switching between multiple PSUs that target different load ranges.) But of course something like that is more expensive...
> But of course something like that is more expensive...
More expensive than an inefficient unit, but it should still be a lot cheaper than 120 separate units, right?
And I expect one big fat unit to do a better job of smoothing out voltage and avoiding flicker than a bunch of single-light units. Especially because the output capacitors are sized for the entire system, but you'll rarely have all the lights on at the same time.
Though for efficiency I'd think you'd want 48v and not 12v.
These days, you should not be using transformers to power small loads at all, you should be using switching power supplies. They have negligible power draw when there's no load attached.
I am flying from SFO -> DEN in a few days and I see that Denver wait time is 4 minutes and, as is well known, SFO does not use TSA or federal security staff.
Denver does, however, so I wonder why there is no wait at DEN and hundreds of minutes at Houston/Atlanta/JFK ?
I’m a frequent flier and flown into all of the above, the ones with TSA issues have been perpetually mismanaged under the best conditions, it’s not even remotely surprising that they are having issues under pressure.
I encourage you - and anyone - to read the excellent book:
_The Making of the Atomic Bomb_ [1]
... and, in this case, to pay special attention to the multiple chapters describing in painful detail just what is involved in refining and extracting Uranium. As in, cubic acres of land mechanically and chemically processed to extract ounces of material ... which is then sent to enormous production facilities, at tremendous cost, only to begin the refinement process.
It is an incredibly long, dirty and energy intensive journey and I am not sure if the ledger of carbon expenses properly accounts for these steps.
I have spent a lot of time in areas that have been impacted by uranium extraction, including wandering around the four corners area and discovering old uranium mines.
Combined with seeing how the extractive energy industry has treated old wells, where they do everything in their power to abandon them and put the burden of cleanup and mainteance of that remediation onto the public, I simply have no faith that nuclear power is "safe" as long as it's private industry doing the work.
I wish that mark pilgrim had not taken his blog off-line… He had a very insightful and moving peace about alcoholism and described it in a very striking and understandable way.
"0-click example: receive an MMS with a malformed image that exploits a bug in decoding ..."
Consider a SMS firewall that:
- flattens text to ascii-256
- recompresses, noises and slightly resizes images and video
... and only then passes the message onto your real (SIM card) phone number.
This, of course, requires that you host your phone number somewhere like Twilio which has other added benefits like additional protection from SIM-jacking and being invulnerable to theft or loss of your handset, etc.
If this firewall is available as a commercial product, eventually it be infected, so there won't be any need to hack any client devices. Since this is clearly a niche product, the device manufacturer won't be able to identify and fix bugs as effectively as companies like Apple do. This follows ROSKOMNADZOR recommendations: to install a middleware device that decrypts, stores, modifies, blocks and redirects all traffic depending on rules submitted from external party.
"I don't think this is good advice to the kinds of people who don't know if they should be running 14.4 or 15.0."
You don't need to wonder about this because FreeBSD has an official, documented position on this topic[1]:
"... include work in progress, experimental changes and transitional mechanisms that may or may not be present in the next official release ..."
"... whether or not FreeBSD-CURRENT sources bring disaster or greatly desired functionality can literally be a matter of which part of any given 24 hour period you grabbed them in!"
"(is not) In any way ``officially supported'' by us."
GP works for Netflix. The team that maintains their FreeBSD stack includes FreeBSD committers, as noted in the linked presentation. Bit of a special case.
With that said, I've quickly upgraded to every production release, including .0 releases, on my personal infrastructure boxes for decades and have never been bitten in the ass or spent more than a few minutes making required configuration changes, and have run -CURRENT on development boxes, where it usually works fine.
As a rough analogy, -CURRENT is a bit like Debian Sid. You probably wouldn't run it directly in production, but it's not an unreasonable option if you have the resources to maintain an internal fork (or, for that matter, as the upstream for a downstream distro).
Side note: Netflix support for FreeBSD is one reason I've continued to subscribe through price increases and periods of low use. Keep up the good work!
What is the ios equivalent?
reply