The trouble is that they successfuly made people believe social and human science are as reliable as hard science, using statistical data as mathematical proof.
My wife works in University, they are the most left leaning people I ever saw, but are afflicted by their own cognitive incoherence.
For exemple they are against student visa fraud, but don't alert that the student never came as they don't want to be the one responsible. They just hope there are some right leaning people like my wife who will pull the trigger.
> Parents appear increasingly terrified of childhood boredom, and thus meticulously cram their children's schedules with activities they feel are "crucial" for "development".
It's insidious, but when my kids have nothing to do, and I see them on the phone. I don't like it and I feel the urge to plan an activity.
Uh, when my son asks me for the phone, I say no, and he asks me why, I just tell him it’s because I think being bored once in a while is healthy. As long as the rules around using it are consistent he can work with that (he’ll start running to get to the bus/train on time too, because he can only use a phone if he can sit down)
one of the reasons NPR is declining so badly, those of us who had to listen to it for hours on end in the back of a hot car and got a kind of bizarro world moss-coane stockholm syndrome aren't reproducing enough to inculcate another generation of mug toting radio listening, garrison keillor on sunday afternoon types
Yep that's the standard in embedded on bare metal without memory allocation.
There is a mechanism in place to synchronise data during interrupts, so it's not really direct write.
Usually also coupled with a two complement variable or similar to make sure memory is not corrupted for safety critical data.
So they drop the voltage to mimic an engine cranking, and they are surprised that the ECU behaves like it is cranking.
When engine cranks, voltage drops below minimum voltage required by ECU to keep SW running (SW resets). To counter these, ECUs keep outputs to the max.
Normally I would expect an electrical loop with the crank signal though.
Depends on the brand and the model, there is a trend towards higher voltages because that implies lower currents and wiring is heavy and expensive.
It started out with (nominally, voltage can rise and fall based on charge levels) (30S) 144V packs, (96S) 352V is very common and there are (192S) packs that do 704V (but that are marketed as 400V and 800V respectively).
You don't want to get zapped by any of these, it's middle voltage DC which is quite dangerous, so the fuses definitely have a safety aspect in case of a crash, they are to protect emergency personnel from touching the frame and exposed wiring. But that's in case of a very serious crash, your average encounter with a rabbit might set off the crash detector (which can't really know ahead of time how bad a crash will be) but has extremely little chance of resulting in exposed wiring. In the case of BMW that rabbit could end up being pretty expensive.
> I'd personally prefer e.g. 48V even if that meant some more losses and/or thicker cables.
That's unfortunately not an option. The problem with the 600 to 1000 V domain is that it is able to creep where lower voltage would stay constrained and high enough that it can jump small gaps and start arcing spontaneously. The fact that it is DC makes it more dangerous still. But from an economy and practical engineering perspective it makes perfect sense. Keep in mind that these cars are often built using Lithium-Ion packs (though fortunately we are finally seeing a change here towards safer options, even if they are slightly less dense and more expensive), so the electrocution risks are small compared to the thermal runaway risks.
Running an EV off 48V would lead to a heavily, heavily compromised vehicle. There just aren’t components that can handle 5-10kA of current with a reasonable size.
Charging speed is directly related to the voltage of the pack. Even if your own vehicle had arm-thick cables to support high speed charging at 48v there is no quick charger in the world that could support it. You would be stuck in the bad old days of needing hours to recharge the battery on your EV.
No it's not, only in a practical sense. If you truly had 'arm thick cables', you could definitely charge a 48V battery just as fast. Practically speaking, though, you don't do this because every becomes so unmanageable that you can't build a charger, bus bars, etc, that would be able to match the charging speed.
The problem isn't the cables in your car, it is the cable between the DC fast charger's transformer and your car. They are already thermally limited, which is why you need higher voltages to support faster charging.
Like I said, this assumes you use ridiculous cabling and bus bars. You could design something that handles this, it would just be wildly impractically large and cost way too much money.
Also, the problem is definitely also the cables in your car. Moving to 48V would mean amperage would increase by 10-20x, which would mean cabling thickness would have to increase substantially.
It’d be a massive waste of electrical conductors to use 48V batteries due to ampacity. Higher voltage means lower ampacity and smaller conductors.
You’d need to use silver plated copper buss bar as conductors, 150kW @ 48VDC is 3125 Amps. I’m not familiar with DC ampacity tables, but you’d need (9) 3” conduits each containing (3) #500 MCM conductors for a three-phase 3125A alternating current circuit. One foot of #500MCM copper weighs 1.5 lbs, so each foot would have 27 times 1.5 lbs or 40.5 lbs per foot.
150kW @ 400V is 375A, a single set of #500MCM can carry the current, 4.5 lbs per foot.
The risk of being shocked by 400VDC while using the car is essentially 0, so they use higher voltage to save on conductor material.
There’s no way in hell I’d ever open up an EV battery myself and I know enough to do it safely. DC is incredibly scary, make sure to discharge your start/run caps if you replace them yourself!
What are you talking about? Yes I know how quickly I can get electrocuted when the battery pack is open. I just need to touch two exposed busbars ~30cm apart. Or my tool needs to touch them.
Exactly, you need to touch both plus and minus. You moved the goalpost from getting electrocuted driving your car due to shoddy quality remanufacturing of battery, to getting electrocuted while repairing the high voltage side of your vehicle. Remanufacturing quality does not come into play if you decide to touch plus and minus side of a HV battery.
Sorry I have no idea about this goalpost moving, maybe it's a language barrier. I'm just saying working on it is quite dangerous. But you can easily get electrocuted by shoddy remanufacturing (especially if someone drilled into the battery to replace a single cell - as EV Clinic shows in their videos), that's why there are additional safeties with regards to bad isolation. So I stand by both takes.
Not so fast. I "saved" guys from being fired by asking to be more patient with them. The last one was not in my team as I moved out to lead another team. Turned out the guy did not please an influencial team member, who then complained about him.
What I saw instead was a young silent guy, given boring work and was longing for more interesting work. A tad later he took ownership of a neglected project, completed it and made a name of himself.
It takes considerably more effort and skill to treat colleagues as humans rather than "outputs" or ticket processing nodes.
Most (middle) management is an exercise in ass-covering, rather than creating healthy teams. They get easily scared when "Jira isn't green", and look someone else to blame for not doing the managing part correctly
Same experience in my village. When you live far from public infrastructure (police, firefighters, doctors etc...) you need to rely on each other.
I miss this spirit in the city
Some people love the fact that they have old appliances still running fine.
I have my grandma Siemens fridge, 30 years old, still running fine.
On one hand, a more efficient fridge would cost less money on the long run, but on the other hand i'm afraid to buy a lemon. So I'm patiently waiting for my Siemens to die
> On one hand, a more efficient fridge would cost less money on the long run, but on the other hand i'm afraid to buy a lemon. So I'm patiently waiting for my Siemens to die
There's a piece of wisdom about cars and appliances that unless there's some egregious defect that turns it into infinite money sink, the least costly (and in fact the most environmentally friendly) option is to run the one you currently have until it disintegrates. Because the price of a new one is usually like your electrical bill for the current one over multiple years, adjusted for inflation and price hikes.
There are of course exceptions, but rules of thumb are never 100%.
I have a 30-year-old Frigidaire upright freezer in my basement. I'd been assuming for a while that it's wasting power due to leaked refrigerant or some such, but I borrowed a power logger from work, and whadda ya know: it's actually reasonably efficient.
The thermostat is dying, so I picked up one of those thermostat plugs with a probe on a wire. Gonna keep it as long as I can. (Plus it's the perfect size for its space, and they don't make that size any more.)
This is the thing, the day they stop working you wonder if you should repair them for X money or byy a new one for X / 1.5 money. Guess which wins in both time and money.
This is the downward spiral for a lot of brands. They sell out to an investor, who uses their brand reputation inertia, reduces cost and quality, etc. There's barely any brands left. IIRC Miele is still one of the few good brands for home appliances, but they're also significantly more expensive. At least for the initial purchase, I'm sure it evens out long term.
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