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This is double bad in a green energy and EV website: On one hand, they admit they don't now why that happens, but on the other hand, they also didn't research just a bit more on that, and that's bad journalism.
Most of the comment threads in this HN post are a lot more informative than the article
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Agreed. 48V (actually -48V) has been used across telco central offices for decades.
It's a really nice voltage with lots of support for batteries and up/dn conversion hardware. It's also right at the edge of what is human safe. You can burn yourself and blow up cables, but it's very difficult to electrocute yourself (afib or muscle seize) without lots of wet contact. https://incompliancemag.com/article/experiments-of-dc-human-...
I can't find a reference for that Swiss case though. I'll keep looking.
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There are pros and cons. Snow plows beat on a the vehicle - which is why plows are the last thing a truck does before you quit using it. Highway departments will use a dump truck mounted plow because the frame of the dump truck can take the beating (that they can put salt on the dump truck is a very useful side effect). Tractors are designed to pull plows through dirt which also beats on them, and so tractors can sta…
You don't use custom-designed vehicles? I'm used to snowplows being these massive, reinforced vehicles that look like they could take on a tank.
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The great thing about PoE standards is there's so many to choose from. https://en.wikipedia.org/wiki/Power_over_Ethernet#Standards_... Honestly, ethernet introduces a degree of non-determinism with respect to time in the link layer, plus increased bringup times, a potentially more costly core switching fabric, and the need for critical revision of latency assumptions on any potentially safety-related control concerns…
Sure. It's also not like there are many ready made devices that are already available for PoE that could be useful in automotive industry. I guess my main thought was that going to 48V and in the world of low power LED lights and such, combining power and comms into same wires/cables is something that might be appealing.
The power over data line (PoDL, automotive Ethernet equivalent of PoE) is defined by a separate IEEE protocol and its critical specifications like EM emissions tests, ESD tests etc are supplemented by documents created by a consortium of car, electrinics, comnector, cablr and semiconductor producors called OPEN Alliance: https://opensig.org/ . There are parts available for PoDL. The voltage levels from 6V to 60V with 6V increments are supported.
Source: I design both data center and automotive Ethernet chips.
>48V architecture also potentially improves overall electrical efficiency for reasons that I am not sufficiently qualified to explain beyond a kindergarten level This is double bad in a green energy and EV website: On one hand, they admit they don't now why that happens, but on the other hand, they also didn't research just a bit more on that, and that's bad journalism. Most of the comment threads in this HN post are…
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weird comment... maybe we shouldn't feel the need to idolize humans...
We humans are all terrible on some level (except my mom, she was a saint), but if you have enormous power, you can help or hurt a lot of people based on your actions. Musk has a lot of power. He must be a terribly lonely person, not knowing if he can trust anyone or they just want something from him.
>48V architecture also potentially improves overall electrical efficiency for reasons that I am not sufficiently qualified to explain beyond a kindergarten level This is double bad in a green energy and EV website: On one hand, they admit they don't now why that happens, but on the other hand, they also didn't research just a bit more on that, and that's bad journalism. Most of the comment threads in this HN post are…
Also, "But don't you dare threaten to replace me with an LLM. Journalism is a sacred cornerstone of democracy and intellectual life!"
Older Tesla cars have a 12V battery for accessories, until the main high-voltage battery is turned on. So does this mean having a 48V accessory battery? Or what?
Why would a car need a 48V system for accessories? In general the things a car's 12V system powers have gotten less power hungry over time (LED's, heat pump) and in particular, an EV loses the highest power electrical device on the 12V bus, the starter. The typical equipment used for the entertainment and control systems are going to be much more available with 12V supplies, just because that's the industry standard.…
Hi, automotive electrical is my job. There's quite a bit of very thick wiring in a car, not just the starter wire, but boring stuff like audio amplifiers, rear window defrosters, power seat motors. Those things don't draw a ton of power, like maybe just a few hundred watts, but at 12 volts even modest powers require extraordinarily thick wires, especially when you account for bundle derating. This requires large term…