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It would be great to have 48VDC in homes, for lightning, light appliances, etc. to centralize the whole power factor control in a single big power supply instead of doing it (poorly, or not at all) at every LED bulb.
Replace all power outlets with Ethernet and have everything run over 48V PoE and get network connectivity too
48Vdc is supposedly the highest voltage that is still considered safe. ( https://electronics.stackexchange.com/questions/267789/how-s... ) It certainly sounds like a smart move on the copper savings alone.
Remember a fully charged lithium battery with nominal 48v can be close to 60v just like 12v in your car is actually closer to 14v.
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It'll happen in RV's first, for obvious reasons. I imagine they'll use USB-C as the standard connector even though it's not the optimal form factor for this usage due to its ubiquity. POE would be a better choice.
Doesn't USB-C cap at 20V?
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Compared to ICE vehicles, EVs are expensive and heavy (according to Slate, an F-150 Lightning weighs 35% more than its ICE sibling). Cost and weight reduction are both important factors for any EV maker to optimize. Why do you assume the 12V bus doesn't drive high-power stuff? Historically, every single electrical component in a car is powered at 12V. Everything. Your alternator outputs 12V to both power your electri…
Compared to ICE vehicles, EVs are expensive and heavy Expensive maybe, IMHO not really, at least in China. Heavy .. this doesn't sound fair. Are you comparing a cherry-picked, heavy, full battery back EV with an empty tank ICE? Noting the EV has far more torque, and that the same tech is used in UAVs and in a ground vehicle you can arguably move the weight around (lower it) easier in an EV, this casual observer (not…
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.…
No matter what voltage or power level you need, higher voltage will allow for smaller/cheaper wires and connectors that are easier to route and assemble.
[1] You can browse the Kicad PCB design directly in the browser with this handy web viewer. The power section is the top left: https://kicanvas.org/?github=https%3A%2F%2Fgithub.com%2FTwis...
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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.
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…
It would be great to have 48VDC in homes, for lightning, light appliances, etc. to centralize the whole power factor control in a single big power supply instead of doing it (poorly, or not at all) at every LED bulb.
The same is true of electronics, you are replacing AC-DC charger with DC-DC charger.
The other big problem is that lots of appliances require more power than feasible with 48V. People are fine with the low-power DC right up until they need to plug in a space heater. Are you going to have two kinds of outlets everywhere? Or incrementally upgrade each circuit? Or are going to upgrade the wiring with super thick cable that can handle the current?
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Because we already have the 12V infrastructure and part supplies in place. You're disrupting things for no benefit. We've been running split 24V/12V systems for decades now in automotive applications. It's not that big a deal to change that to 48V/12V systems as many European car manufacturers have done.
No benefit? I've seen estimates of $1000 in reduced cost due to reduced copper wiring, and more importantly the labor required to string that wiring. Modern phones charge on 48V these days, so 48V parts are extremely common & cheap.