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Re:Never trust a system that seems to be working by adrian_b on Monday October 17, 2022 @12:04PM (#33235502)
This happens because the real insulators are better approximations of ideal insulators, than real conductors are approximations of ideal conductors.

In electrical circuits made with normal conductors and insulators, e.g. copper wires and organic polymer insulators, it is possible to ignore the currents that branch from the wires and close through the insulators, because they are extremely small (e.g. in the femtoampere range), but frequently it is not possible to ignore the voltage drops along the copper wires, which are caused by the resistances of the wires, and which may be in the millivolt range.

Re:Never trust a system that seems to be working by lisper on Monday October 17, 2022 @12:11PM (#33235623)
I have a bachelors degree in electrical engineering and work experience in hardware design and in the back of my mind I've always known this to be true, but this is the first time in my life I've ever heard anyone say this explicitly. EE pedagogy is badly broken in places.
Re:Never trust a system that seems to be working by freedomben on Monday October 17, 2022 @12:39PM (#33236069)
Indeed, when discussing theory we love pretending that there's no voltage drop from the wires, which can really bite you when you get into design or deep failure analysis. All good technicians and engineers learn this reality fairly soon, and it's one of the things we check especially when dealing with indeterminate failures.

As much as I love academia, I really wish there were more instructors with real experience that could say things like, "for math purposes assume a zero-loss conductor" while still emphasizing that real life is not so simple.

Re:Never trust a system that seems to be working by deepspace on Monday October 17, 2022 @01:00PM (#33236440)
Maybe it has to do with the culture at specific schools. As I mentioned in another comment, my instructors loved to include wire resistance in their problems, and always explicitly stated the zero-loss assumption when applicable.

We did have a healthy incubation program, where instructors helped companies with product development, so perhaps that is what brought the real-world experience.

Re:Never trust a system that seems to be working by deepspace on Monday October 17, 2022 @12:55PM (#33236342)
As another EE, I had the opposite experience. Voltage drops due to wire resistance and transmission losses were drilled into our heads at any possible opportunity.
Re:Never trust a system that seems to be working by hermitdev on Monday October 17, 2022 @01:28PM (#33236883)
Difference between focusing on digital vs analog, maybe? As another EE, I vaguely recall this being pounded into us more in power systems than any of my digital electronics courses.
Re:Never trust a system that seems to be working by ip26 on Monday October 17, 2022 @11:06PM (#33242502)
Sounds like you missed the “actually, all those digital wires are transmission lines” class :)
Re:Never trust a system that seems to be working by mschuster91 on Monday October 17, 2022 @02:51PM (#33237958)
> EE pedagogy is badly broken in places.

Generally, the biggest problem with math, physics and chemistry is that if you miss just one lesson (no matter if you physically miss it, or in worst case miss out understanding a concept for a couple minutes), you can easily end up "left behind" for years. With history, arts, languages, a number of computer science topics or most of biology you can either skip out on a certain subject or catch up easily on your own, but not getting a specific part in math/physics/chemistry and lacking the resources to follow up is setting oneself up for exponential learning gap later on.

The societal problem is that we've not set up schools or universities to deal with this "failure mode". Privileged kids can have after-school teaching or siblings helping out, but most will sooner or later resign and hate these subjects for the rest of their lives - and that is incredibly sad.

Re:Never trust a system that seems to be working by nrb on Monday October 17, 2022 @09:57PM (#33242093)
If only we had the technology to somehow record lessons for later viewing or for refreshing knowledge later, and additional catch-up materials & deeper dives into the topics. This seems like extremely low-hanging fruit.

Why do I get a sneaking suspicion that few in the machinery of education want this, as it is a fast-track to continuous accountability?

Re:Never trust a system that seems to be working by BenjiWiebe on Monday October 17, 2022 @02:55PM (#33238016)
You will also get voltage drops from the sensors using power along your current loop as well, no? Whereas current will be the same along the entire loop all the time.