Work/worked for a place that was doing this. There's a couple problems:
* More battery weight means less cargo weight
* Trailers are dumb; the standard hookup (in NA) is lights and air. I hear CAN is common in EU though.
* Trailers are cheap and almost disposable.
The trucking industry is very slow moving, and probably 20 years behind passenger cars. So changing any of this stuff, even though none of it sounds particularly major, is at least 15 years out to start. Then you're left with the hundreds of thousands of "legacy" trailers that need to be retired or retrofit. The tractor to trailer ratio out there is like 1:10.
One interesting use case for this though is refrigerated (refer) trailers. They're often diesel-electric so they can plug in to shore power. Add a battery to this and maybe you can dump the diesel motor. Again though, weight is an issue... diesel is an order of magnitude more energy dense than the best batteries we have.
Voltage spikes from line inductance, voltage drop-outs from line resistance. Basically you have little reservoirs of charge scattered all around the board (current flow isn't instantaneous in a real circuit).
It helps to always think of current draw in a compete loop, out the "top" of the capacitor, through your IC, and back into the ground side (this isn't necessarily what's happening physically). Shorter loop means less inductance, shorter traces less resistance.
> I thought it is pretty well accepted there isn't a "gravaton" like there are photons.
Different branch of physics that we can't quite mesh with GR yet. A graviton is the quantized "piece" of gravity, like phonon is for sound/mechanical waves, or photons for EM. It exists as much as a photon or any other "messenger particles" exists, in that it's a useful mathematical model. It's not something we have isolated/observed with equipment though.
Meh you don't need a PE to be an engineer. That's stretching the gatekeeping too far. PE is valuable for a lot of things, but not necessary for a lot of actual engineering work. Is a trained and working electrical engineer not an engineer because a PE isn't necessary to design and build sensors, loggers, etc?
PE essentially just means you can legally sign off on safety critical designs. Engineering is the application of math and physics to solve a problem.
Anecdotally, the handful of PEs I know are the pencil-pusher types. They're engineers on paper, but a critical skill for engineering is actually building stuff.
> TL;DR - Your deep cycle battery approach may not prove to actually be worthwhile, consider working out the car-as-generator hookup plan in advance.
Ha yep, learned that the first time and was ready to go with an extension cord the second time I needed this setup. First time, I had a stash of 3 batteries but I didn't realize how much power the blower motor would draw, so I was charging on the car and swapping out batteries as needed. Did that the first day then rigged up cords for day 2. Halfway through day 3 we got power back.
My strategy is a deep cycle car battery and harbor freight inverter to run the blower motor. You get a long enough extension cord and you can use your car as an emergency generator.
I'll bite I guess. I use Calibre pretty regularly. I think a general way to put it is that it's not for "casuals". To understand a lot of the functionality outside of the basic inventory management stuff, you have to be a little bit of an enthusiast. For some examples: You have to know about different ereaders and their formats and how they differ, the differences between metadata sources, and dozens and dozens of configuration options if you're trying to convert a book to work well on your device.
Also, there's definitely something "off" when it comes to using it intuitively. I have to devote a lot of brain power to searching for functionality AND trying to comprehend exactly how those pieces of functionality are going to affect my library data.
Maybe it's too powerful of a tool up front or something. It could benefit from a "basic view" maybe?
None of these are complaints from me, I'm a happy user. I'll just echo some other commenters in wishing for a more robust network interface (whether that's just an API, or a more hashed out front end). I'd like to easily share my library with people or just other devices while on-the-go, and Calibre has all the device formatting functionality built-in.
Truck manufacturers measure fuel efficiencies to the tenths and compete on that. At highway speeds, ICE engines win over a pure electric system, so throwing in another conversion step hurts. For city routes, pure electric is better than diesel-electric.
So in general, the disadvantages of a diesel-electric system outweigh any advantages when you take a look at how trucks operate.
New trucks have "automatic" transmissions (not torque converters- they're more like automatically shifting standard transmissions), so no manual shifting required.
Somewhat related, but refrigerated trailers ("refers") often use a diesel-electric system because it's easy to plug in to shore power and cut the diesel engine.
Soldier is on losing side of war, was unable to go through with morally objectionable orders, comes home to find everyone they ever knew died in bombing campaigns, and over time has to learn how to deal with the psychological and physical toll the war left on them.
But of course that's an absurd premise because Nazis and apparently the Japanese are not humans and therefore can't have human-like stories or something I guess.
Shit and you're not even the same person who commented above that all Japanese movies should essentially be 2 hours of Japanese actors apologizing for war atrocities their country committed 80 years ago.
People don't like accepting them because 1. It feels like a huge denomination, and with that comes fear of mishandling and counterfeits, and 2. You have to then make change... and you only have so much of that
And then on the customer's side, you're just back to carrying a bunch of 20's and 10's
Ethics is (often?) required in engineering curriculum, but it's mostly along the lines of "don't lie about work you didn't do then charge for it". There's nothing that touches on only using your powers for good. Like building 'autonomous' cars then letting them loose in public before they're proven, or building out algorithms designed to get people addicted to rage bait, or building in planned obsolesce, or building a device that uses WiFi to map out a private domicile without the occupant's knowledge.
Engineering ethics courses all boil down to "don't lie about stuff", not "think about the potential consequences of what you're building".
> We don't even own a tractor because it's not economically viable to take on the upfront or maintenance costs of modern tractors.
This is a little bit ridiculous. A tractor is an invaluable tool and there's tons of them out there that are as old as 60-70 years and still running great. You don't need a brand new GPS-guided john deere with a dealership maintainence plan to work a small ranch; $5-10k will get you something that is old, but easily maintained and will last forever.
* More battery weight means less cargo weight
* Trailers are dumb; the standard hookup (in NA) is lights and air. I hear CAN is common in EU though.
* Trailers are cheap and almost disposable.
The trucking industry is very slow moving, and probably 20 years behind passenger cars. So changing any of this stuff, even though none of it sounds particularly major, is at least 15 years out to start. Then you're left with the hundreds of thousands of "legacy" trailers that need to be retired or retrofit. The tractor to trailer ratio out there is like 1:10.
One interesting use case for this though is refrigerated (refer) trailers. They're often diesel-electric so they can plug in to shore power. Add a battery to this and maybe you can dump the diesel motor. Again though, weight is an issue... diesel is an order of magnitude more energy dense than the best batteries we have.