Thanks for articulating this as I never understood why iOS suffers from this phenomenon. The only other place I've seen "typing too fast" result in garbled input is on Android based VoIP phone handsets, where if you try to "type" numbers too fast some of them get dropped - an amazing example of a device with many orders of magnitude more computing power than what it replaced still managing to be less performant.
As a practicing EE (power systems), I agree. It often becomes clear when someone is unable to distinguish a practical limit (this equipment is not rated for X, our operating procedures prohibit doing X) from a physical one (X is not possible because of underlying physical principles).
This. There are so many real world, practical, and pragmatic uses for EE. This example, which is basically knowing that the hardware specifications cannot meet the claims that are being made about a product, in an accurate or reliable fashion, is one I use on an everyday basis.
You don’t fall for marketing gimmicks.
Another thing is you know the relative price (ballpark figure) of the technology, as in how much it costs to make something, often just by eyeballing the actual product or by looking at its specifications. Sometimes this translates to more abstract and somewhat unrelated fields such as medications (if you read the patents and study them).
As you note, for facilities like data centres that are engineered for a specific type of load, a building-level rectifier makes sense. For a home where you have many devices using a little bit of power at a variety of voltages, you're going to end up with lots and lots of small DC converters everywhere which defeats the point. Just run 120 VAC.
Even if power generation is distributed and localized, you still need higher voltages than what is in a home to transmit it unless you're talking about not having a power grid at all. You still need voltages on the order of 1 to 40 kV to distribute power around a neighbourhood, for instance. You aren't going to wire your house at distribution voltage - it would be expensive and unsafe.
As it is, typical home electrical systems have no active components. There are just wires, panels and bimetallic circuit breakers. These systems are nearly maintenance-free over a lifespan similar to that of the structure.
A DC distribution system in the home would require both a high power rectifier at the main panel to something like 125 VDC, then many smaller DC/DC converters throughout the home for your usable voltages like 5/9/15/20 V that are too low to be effectively distributed.
All of those things would need to be maintained and upgraded over the years, because there is no such thing as power electronics that last forever. After a few electrician visits, you might find that you haven't saved any money at all.
Even if you have solar, you still need a DC converter because it will not output a constant voltage let alone all of the DC voltages you need for your devices. And generation any further away than your own rooftop is going to need to be stepped up to higher-than-home voltages and then back down for use in your home - all of which is exactly why we currently use AC for distribution.
You forgot the magnetic trip of the breakers and the now-mandatory RCDs. The latter are far more complex than a simple rectifier would be.
And even then, there's no reason such a rectifier module couldn't be a pluggable module. They still last 10~20 years, easily.
I don't see what all those low voltage rails should be for. Computers typically work fine on 300~350 V DC, and if anything, there is reason to go from 12 V to a higher supply bus voltage, actually deployed in some modular servers by now (with a 48 V bus between the local battery backup modules, AC-fed supplies, and motherboards).
The ostensible benefit to DC distribution in homes is to be more economical and simpler for devices that already run on DC - not to redesign ever device ever made to accept mains-voltage DC. If your iPad and your laptop and your blender still need a power brick to work, what's the point?
Using high-voltage unnecessarily to avoid using a DC converter is also not going to save money. Yeah, you can use a 300 V DC motor in a coffee grinder, but why? It's just going to cost more money to make.
90% of things in your home would happily run from 150V DC, even though they aren't rated for it.
Source: I sometimes connect my solar panels direct to my AC wiring without an inverter, and my house works entirely except my washing machine and fridge (both of which have AC motors in). Even my vacuum cleaner works (although it's on-off switch doesn't work, since it uses a thrysistor!). Phone charger, laptop charger, oven, microwave, doorbell, furnace, routers, TV, monitors, desktop pc, all work fine.
If some country declared tomorrow that all electrical devices must accept AC or DC, not that much would have to change.
I had no idea about this. Can it damage things that won't work (eg things with AC motors).
I've been building out electrical in a campervan and always wonder if there were DC equivalents to a lot of things.
My point is, that the European accidentally-DC-capable mains equipment can be expected to complain/sustain overcurrent damage, provided it isn't able to handle US residential voltages.
Hence you might as well take the opportunity and switch to a higher in-house distribution voltage than the typical 120 V.
And that 300 V DC motor may actually be cheaper, as you could run a BLDC driver directly from the DC supply with just minimal filtering.
The enhanced power density and copper-efficiency of these high-frequency 3-phase motors may make up for the cost of said inverter, even neglecting the considerably increased energy efficiency over a typical single-phase-capable "oldschool" motor.
Yes, but single-stage conversion from 48 V to ~1.2 V core/memory voltages is inefficient with the typical buck topology, due to the low duty cycle.
There are solutions based on ZCS (+ZVS) (semi-)resonant switched capacitor topologies that could (technically) do this in essentially one stage. But because they are still somewhat recent and rely on either GaN enhancement-type FETs or low-average-blocking-voltage topologies that make use of e.g. small 5V-capable IC process nodes and some tricks to have the individual power transistors floating.
In several instances I've seen, it's because that function has been outsourced but the company doesn't want to advertise that, even to its own employees. If you could talk to that department on the phone, you'd realize you were talking to someone in a different country (plus they'd have to work at strange hours in India, the Philippines, etc.).
You should check if your device can run a third party ChromeOS distribution that is still updated, like Cloudready. That's what I did with my Asus CN60 that would otherwise have become a doorstop without security patches and it runs perfectly.
This model uses ARM. There's only one alternative to the default ChromeOS on the Flip: Arch, which has an extensive writeup about this model on their wiki. Pity it's not Intel, or I'd have a wide variety of options.
Cloudready is great though. I've tried it on multiple machines and had great results every time. Still hoping for a Cloudready Pi port now that Google owns Cloudready.
Some of the EOLed devices are commodity x86 hardware and can run the latest Linux distros or Windows 10 if the bootloader is unlocked, which really shows how arbitrary Google's end of life policy is.
Diesel engines for power generation will have a governor control that sets the throttle based on the load to maintain whatever rpm is required for 60 Hz (constant speed control). The load in this scenario is uncontrolled and the genset simply follows it.
A diesel locomotive's engine controls are about producing the right amount of power to match the operator's throttle control. Electrical frequency at the generator (alternator) terminals is irrelevant since that output is being rectified to DC anyways. This is great for a train, because it means you can have full power at any speed - the speed of your train and the speed of your engine are completely decoupled from each other. But if you now connect this normally variable frequency AC output directly to 60 Hz loads, you will need to figure out how to set the throttle to best maintain something close to 60 Hz and your power output will be limited.
