[HN Gopher] Standardizing Automotive Connectivity
___________________________________________________________________
Standardizing Automotive Connectivity
Author : hardikgupta
Score : 153 points
Date : 2024-10-28 19:09 UTC (1 days ago)
(HTM) web link (www.tesla.com)
(TXT) w3m dump (www.tesla.com)
| taylodl wrote:
| _> Tesla invites all device suppliers and vehicle manufacturers
| to join us in this initiative._
|
| This is not a standard in the sense that engineers use the term.
| Tesla is _hoping_ it will be adopted as a standard and since
| Tesla doesn 't appear to want to involve any standards bodies,
| Tesla appears to only be interested in making these connectors a
| de-facto standard.
|
| In any case, that is not a standard.
| instagraham wrote:
| Relevant xkcd, though one imagines that successful standards
| form despite the lack of choice in how standards are formed
|
| https://xkcd.com/927/
| Someone1234 wrote:
| The XKCD doesn't really apply here, since intra-vehicle 48v
| is kind of unexplored, so there aren't multiple competing
| standards for that in particular. I do agree that this isn't
| a real open and free standard however.
|
| edit: Inter to Intra.
| duskwuff wrote:
| Nitpick: _intra_ -vehicle. Inter-vehicle power would be
| pretty weird.
| toss1 wrote:
| True, but Inter-vehicle could be cool for several things.
| First is the EV equivalent of jump-start-and-bring-a-can-
| of-gasoline, an in-the-field recharge for cars that run
| out before the recharging station or home charger. It
| would also be useful as a plug for a range-extending
| spare battery pack on a small trailer. Seems like other
| potential uses too.
|
| (But no, I'm not liking that Tesla is taking the typical
| entitled-ass attitude of avoiding all the standards
| bodies, doing whatever they want, and expecting others to
| ratify their standard. If it is that good, it should be
| readily agreed to by the relevant standards bodies.)
| SideburnsOfDoom wrote:
| > Inter-vehicle could be cool as the EV equivalent of
| jump-start
|
| This exists:
| https://news.ycombinator.com/item?id=41975736 But for
| Lucid, not Teslas. And also more generally as a use of
| V2L.
|
| > in-the-field recharge for cars that run out before the
| recharging station
|
| This exists: https://www.fleetnews.co.uk/news/latest-
| news/2023/06/30/elec... https://www.taxi-
| point.co.uk/post/rac-to-equip-breakdown-van...
|
| > a range-extending spare battery pack
|
| This is a real Tesla Cybertruck accessory:
| https://insideevs.com/news/706702/tesla-cybertruck-range-
| ext...
| vaillancourtmax wrote:
| I think they meant "across manufacturers".
| reaperducer wrote:
| _Inter-vehicle power would be pretty weird._
|
| Sounds like jumper cables.
| duskwuff wrote:
| You know what? You're right. That's literally jumper
| cables.
|
| But no, I don't think Tesla is doing those.
| SideburnsOfDoom wrote:
| Tesla vehicles do not currently support V2L or V2G,
| although many other EV makes do.
|
| But it does seem that Tesla is planning to do those some
| time:
|
| https://cleantechnica.com/2023/08/19/tesla-plans-to-
| adopt-bi...
|
| https://thedriven.io/2024/05/06/teslas-take-
| on-v2g-controlli...
| Pet_Ant wrote:
| Honestly that would be awesome. I still dream of
| autonomous vehicles auto-convoy and link up for
| efficiency. Just quietly become a train as needed.
| SideburnsOfDoom wrote:
| Why is it that when describing EV technology, HN people
| have a tendency to frame it as "imagine if it _could_ ,
| that _would be_ amazing _if_ "
|
| While describing stuff that exists in some form, and
| usually has existed for years already now.
|
| It's not evenly distributed new tech for sure (1). But
| maybe it's the false assumption that "if it was anywhere,
| I'd be among the ones to see it early".
|
| 1) See William Gibson: "The Future is Already Here, it's
| Just Not Very Evenly Distributed."
| SideburnsOfDoom wrote:
| > Inter-vehicle power would be pretty weird.
|
| That's entirely possible at present. Many electric
| vehicles can send power out to power appliances. It's
| called "Vehicle to Load" or "V2L".
|
| And electric vehicles can slow-charge off a wall power
| socket, so they could get that from V2L. It won't be a
| common use, but it would work in a pinch to get you
| enough juice to get to a better charger?
| jsight wrote:
| Lucid supports this directly too:
| https://lucidmotors.com/stories/introducing-rangexchange
|
| <10kw, so not super fast, but I bet most people are
| really close to the charging station when they run out.
| vel0city wrote:
| I agree. Is this some kind of free licensing for these
| connector standards or are they still behind the "you can use
| this but if we rip off any of your IP and you sue us we'll
| revoke your license and sue you" license?
| kotaKat wrote:
| They have a "patent pledge" for their patented parts, at
| least -- they will "not initiate patent lawsuits against
| anyone who, in good faith, wants to use our technology".
|
| https://www.tesla.com/legal/additional-resources#patent-
| pled...
| vel0city wrote:
| Yeah, and they define good faith in that document as:
|
| A party is "acting in good faith" for so long as such party
| and its related or affiliated companies have not:
|
| asserted, helped others assert or had a financial stake in
| any assertion of
|
| (i) any patent or other intellectual property right against
| Tesla or
|
| (ii) any patent right against a third party for its use of
| technologies relating to electric vehicles or related
| equipment;
|
| So, if another company rips off your IP but Tesla doesn't
| think it is a "knock-off product", you sue that other
| company, you're now in violation of Tesla's "patent
| pledge". Its an attempt to use a carrot of Tesla's patents
| to make all the other rightsholders essentially give up all
| their IP. If you sue anyone protecting your EV IP, you're
| in violation of this agreement and will be open to
| litigation by Tesla.
| 1234letshaveatw wrote:
| like NACS ?
| elchananHaas wrote:
| There are different types of standards. Car design teams are
| big organizations; internal standards can help reduce the
| development effort. Tesla needs to coordinate with their
| suppliers, so sharing this helps even if it isn't used by other
| companies.
|
| I think we should give Tesla the benefit of the doubt for now.
| Harmful use of patents could cause issues, but this has
| potential. We will simply see if other companies are
| interested, and if they are it can go from internal standard to
| de facto standard to formalized standard.
| electriclove wrote:
| I'm not sad they didn't work with a hundred companies and take
| tens of years and still have nothing to show for it.
|
| They are doing what they need done for their business and then
| inviting others to join. And way earlier than they did with
| NACS: https://www.tesla.com/blog/opening-north-american-
| charging-s...
| yegle wrote:
| Huh I noticed this section in the linked NACS post:
|
| > As NACS is now recognized in a SAE recommended practice
| (RP) under SAE J3400, we have removed the technical
| specifications and CAD from our website.
|
| So something that was previously freely available now
| requires a $300 payment to access.
|
| I'm sad to see that.
| MichaelZuo wrote:
| I don't think the SAE has the authority to remove anything
| from the public domain?
|
| It likely is still freely shareable for existing copies.
| Ajedi32 wrote:
| Yeah, there are advantages to the "just do it" approach to
| standardization vs design by committee. A lot of web
| technologies started out that way (arguably most of them
| actually). Both approaches are valid.
| throwaway19972 wrote:
| > I'm not sad they didn't work with a hundred companies and
| take tens of years and still have nothing to show for it.
|
| what a ridiculous counterfactual. We have plenty of wildly
| successful standards that weren't just thrown at consumers
| and called a standard.
| saturn8601 wrote:
| IDK man, when I think of standard connectors I think of
| clunky junk: CCS which was all engineering and no focus on
| human centered design with its clunky connector that also
| wiggles in ports.
|
| _all_ of the USB connectors including USB-C, with it
| mandate to support so many different edge cases that cause
| cables to not always be compatible with each other
| defeating the purpose.
|
| Bluetooth again with so many edge cases that made it
| terrible until Apple came along and cut a lot of that out
| in their solution finally made it tolerable.
|
| Hell even a lot of electrical connectors (such as the US
| outlet) suck: developed in that way due to historical
| interests, it looks terrible, is not entirely safe (ie.
| ground does not go in first) and now has stuff bolted on to
| make up for its shortfalls. (GFCI, in line fuses etc.)
|
| Now there are probably loads of terrible proprietary
| connectors but it seems like the free market eventually
| takes care of disposing of the chaff. That itself is a
| forcing function to get to a better design that users will
| like. Whereas you have no choice of a standardized
| connector because some "standards body" made up of opposing
| interests artificially keeps lousy designs around and
| forces it upon the population.
|
| Im not arguing for one or the other but its just annoying
| that standards bodies always seem to get a pass when in my
| experience they produce a lot of mediocre stuff.
| binoct wrote:
| The points of standards is that they solve one or more
| problems for many constituents well enough so that all
| adopters gain in things like supply chain, design ease,
| and interoperability. They are rarely going to be optimal
| for every specific use case. They also often derive from
| specific designs by a specific company
|
| Adding a standards body into the mix is going to add
| complexity to the process by definition, but shouldn't be
| taken as a default "bad", since there are tangible
| benefits to non-corporation-managed standards. Otherwise
| they wouldn't exist.
| kortilla wrote:
| Name the "wildly successful" standards you are thinking of
| and then look into the history of them. You'll find one or
| maybe two major players that pushed it initially.
| throwaway19972 wrote:
| Ok? I'd rather trust DARPA than private enterprise.
| kortilla wrote:
| You didn't name any.
|
| BGP, 802.11, QUIC, HTTP, SSH all came from dominating
| implementations.
| foxglacier wrote:
| It's going to be a standard within Tesla, so in that way it's a
| standard. It sounds like they anticipate benefitting from cost
| reduction themselves even if nobody else uses it.
| moralestapia wrote:
| If you want to be pedantic,
|
| What is a "standard" then? Does it need to have an ISO seal?
| hardikgupta wrote:
| That's fair. Should have said "Tesla _proposes_ new standard
| electrical connector ".
| jsight wrote:
| Don't think of it as a standard as-in SAE, but a standard as in
| "molex", "AT", or "ATX". Yeah, they aren't really "standards",
| but they aren't exactly proprietary either and they also are
| clearly useful.
|
| The goal seems to be to promote reuse of a good-enough design
| in as many places as possible. Noone's forced to use it, but
| it'd make things simpler for everyone if there is as much
| commonality as possible.
| kortilla wrote:
| Most useful standards did not originate from standards bodies.
| The standards bodies just formalized what already had buy-in
| from the significant players.
| hoseja wrote:
| Tell us about NACS.
| tapoxi wrote:
| NACS is finally standardized as SAE J3400 with other vendors
| shipping those cars in the United States next year, and now
| they're introducing a new connector with no clear advantage?
| Someone1234 wrote:
| If you clicked the link/read the article, you'd realize this is
| an internal vehicle 48v connector.
| tapoxi wrote:
| Ahh thanks, I read it but In was confused why it was talking
| about 48v as if that couldn't be done by the other standards.
| unsnap_biceps wrote:
| > The 48V architecture is the optimal long-term choice, requiring
| 1/4 of the current to deliver the same amount of power.
|
| Is there a reason why 48V is better long term than going higher
| like 96V?
| two_handfuls wrote:
| I believe 50V is a safety limit.
| cptcobalt wrote:
| Below 50v is considered "low voltage". Higher voltage would
| require different safety considerations.
| outworlder wrote:
| And that's because of your skin resistance. Around 50V is
| when voltage starts to overcome it.
| rcxdude wrote:
| _usually_. It 's very possible to get a shock off of
| significantly lower voltages in bad conditions (very sweaty
| skin, for example).
| hmottestad wrote:
| 48v is probably more common than 96v in general, so more
| components available already.
| 8note wrote:
| For which - why standardize around this connector and not
| XLR, which is the first thing that comes to mind for 48V?
|
| Too big/bulky?
| zaxomi wrote:
| The phantom power at 48 volts used with XLR connectors only
| have a current at about 10 milliampere. Enough to supply
| power to a little microphone.
|
| The connector is bulky and of metal, and designed to be
| used inside. It's also expensive compared to other
| connectors. There are a lot of cheaper, more suitable
| connectors, designed to carry power.
| matrix2003 wrote:
| As mentioned in another comment, it's also close to the
| safety limit for low voltage systems.
|
| IMO solar pioneered (in recent history) 48V DC systems, which
| is an easy multiple of 12V to stay below the 50V "high
| voltage" safety threshold.
|
| It allowed people to use smaller gauge wire and chain
| together multiple 12V batteries that are readily available.
| bryanlarsen wrote:
| Telephony has been using -48V as a line voltage for a very
| long time, probably > 100 years.
| matrix2003 wrote:
| Is that for power deliver, or signaling?
| Kirby64 wrote:
| Both. It powers old school telephones.
| p_l wrote:
| -48VDC was standard for powering telephone equipment, and
| is also common standard for direct current datacenter
| connections.
|
| Signaling on POTS easily hit over 100V, btw.
| amanaplanacanal wrote:
| I remember getting zapped when the phone rang when I was
| a teenager back in the 70's. Good times.
| Plasmoid wrote:
| At some point, safety.
|
| A short/failure at 100V is much more dangerous than at 50V.
| Both from a fire-safety perspective as well as an electrocution
| risk perspective.
| cyberax wrote:
| Other people already mentioned safety. But you can actually go
| to 96V if needed by running a cable with -48V if you need extra
| power.
|
| One another advantage of the new 48V architecture is that it
| doesn't depend on the car body for the current return path.
| This opens up possibilities of adding sensors that detect
| current leakage, to pinpoint areas with defective wiring and/or
| components.
| zaxomi wrote:
| Depending on the country you live in, the laws might allow you
| to do work on equipment that is below 50 volts, but require you
| to be a certified electrician for anything above that.
| sitkack wrote:
| They would have to 100% open this up and give it to standards
| bodies, otherwise it isn't a standard. The conformity tests and
| testing equipment designs and protocols should be freely
| available.
| duskwuff wrote:
| For that matter: who's going to be manufacturing and supplying
| these connectors? Tesla? I don't think so.
| themaninthedark wrote:
| Generally a connector manufacturer would make these,
| Amphenol, Aptiv (formerly Delphi), Cinch, JAE, JST, Molex, TE
| Connectivity, Yazaki. See Mouser for some
| examples(https://www.mouser.com/c/connectors/automotive-
| connectors/#)
|
| Usually they create their own design so maybe having an open
| standard would allow you to do contract orders with any
| plastic injector that has the molds.
| inferiorhuman wrote:
| Anyone really. If you look at the quick connect fittings
| commonly found on German cars they're all built to a standard
| (VDA not DIN in this case) but built by the NORMA Group or
| Parker.
| FriedPickles wrote:
| > _LVCS...is available in industry-standard light blue_
|
| Is this tongue-in-cheek, or is there a reason manufacturers care
| about the color?
| Aloisius wrote:
| They tend to color-code connectors in vehicles by voltage for
| safety reasons.
|
| Light blue is used for 48V.
| plorg wrote:
| Meanwhile 12V connectors turn up in a wide variety of grey,
| where different colors might just mean the connector is keyed
| differently.
| dtparr wrote:
| In various industries, colors are used to differentiate between
| various voltages so it's obvious whether you're working with
| high voltage, low voltage, etc. so you can determine the
| necessary precautions for whatever you're dealing with (and
| some will also make the connectors incompatible so you can't
| accidentally join high and low voltage sets of wiring). I'm not
| super familiar with the automotive side, but I believe they use
| orange for high voltage and light blue for 48v.
| 7thpower wrote:
| Mid voltage (~48-60) uses light blue.
|
| Ideally you should be able to differentiate high voltage
| (orange, iirc), safety (yellow), mid voltage, and everything
| else.
| cyberax wrote:
| Tesla really deserves some kudos for pushing the 48V architecture
| and the Ethernet-based communication. It drastically simplifies
| the wiring mess that is in a typical car.
|
| And it's not even close. Just watch the teardown of Cybertruck
| and compare its wiring to something like F150.
| outworlder wrote:
| We can simplify the wire mess today by using more CAN bus
| devices.
|
| What is ethernet bringing to the picture?
| the_mitsuhiko wrote:
| Central bus instead of many point to point connections. Look
| at how much fewer cabling the cybertruck has.
| rcxdude wrote:
| CAN is also a bus, that's not really a point in favor of
| ethernet.
| elcritch wrote:
| Ethernet can do both bus and switched. High speed
| switches enables a lot of architecture not easily enabled
| by CAN.
| mulmen wrote:
| Bandwidth?
| KK7NIL wrote:
| > What is ethernet bringing to the picture?
|
| Over 3 orders of magnitude faster datarates.
|
| CAN FD: up to 5Mb/s
|
| Automotive Ethernet: up to 10 Gb/s
| gregoriol wrote:
| Why would you need 10 Gb/s speeds in a car
| the_mitsuhiko wrote:
| Why would you not? Tesla is sending even the
| infortainment data stream through that bus. It's
| incredibly helpful having all data travel on a singular
| wire because you can tap in at one point and read it all
| out. Makes the entire system significantly easier to
| debug, understand and develop against.
| gregoriol wrote:
| And hack/steal, right?
| vardump wrote:
| 10 Gb/s is not all that much for cameras. Enough for one
| 60 Hz 4k 14-bit depth camera transmitting raw bayer data.
|
| 60 Hz * 3840 * 2160 * 14bit is 6.96 Gbps.
| dpeckett wrote:
| It's a good thing we invented video compression and
| hardware codecs/encoders a long time ago.
|
| What you'll actually be sending is a high bitrate mpeg
| stream, probably 54Mbps or thereabouts, you could
| probably fit 50x camera streams on a shared 10Gbps bus.
| nunez wrote:
| FSD will benefit from high-resolution (4K or above)
| camera feeds (for things like reading signs and detecting
| small obstacles). You can do this in a 10Gbps network and
| have tons of headroom for every other function the car
| will perform.
| aeternum wrote:
| Bitrate and max devices for CAN are limited.
| cyberax wrote:
| CAN is slow. At best it's around 1Mbit, but you get into
| electrical limitations. So you have to run multiple CAN buses
| in parallel and carefully manage bandwidth limitations.
|
| My Chevy Volt had 4 different CAN buses and one additional
| LIN bus.
|
| This can all be replaced with just two Ethernet buses: for
| safety-critical and non-critical uses. And the gigabit speed
| provides plenty of bandwidth for any reasonable sensor
| traffic, even including camera feeds.
|
| The current architecture was justified in 90-s when LIN PHYs
| were an order of magnitude cheaper than even CAN PHYs. Now
| Gigabit Ethernet PHYs cost less than a dollar.
| eschneider wrote:
| It's unlikely that the multiple CAN buses are being used to
| increase speed by, say multiplexing them. In general,
| vehicles use multiple CAN buses for enhanced security. For
| example: things like diagnostic ports are often on their
| own CAN buses so data can't be directly injected into
| onboard systems.
| cyberax wrote:
| All but one CAN bus in my Volt were connected to the OBD
| port. The unconnected bus controlled the high-voltage
| battery contactors and some other critical stuff.
|
| The "main" bus was saturated with data, more than 80% of
| bandwidth utilization at 512kbs. And it kinda had a mix
| of everything, from street names to be displayed on the
| dashboard to ECU messages. The other two buses had some
| random messages, with no rhyme or reason for the split (
| https://vehicle-reverse-
| engineering.fandom.com/wiki/GM_Volt ).
| throw0101d wrote:
| > _What is ethernet bringing to the picture?_
|
| More speed and zonal architecture:
|
| * https://www.electronicdesign.com/markets/automotive/article
| /...
|
| * https://www.bosch-mobility.com/en/solutions/control-
| units/zo...
| bsder wrote:
| Larger packets and bandwidths.
|
| Bandwidth: you can't ship backup camera video or
| entertainment system audio over CAN, for example.
|
| CAN was meant for short, real-time packets. 8 bytes in
| initial configuration. CAN FD allows 64 byte packets.
|
| You spend a _LOT_ of protocol doing packet fragmentation and
| assembly using CAN--which then negates a lot of the real-time
| guarantees.
|
| CAN should be used for the short safety critical stuff.
| Ethernet should be used for everything else.
| elcritch wrote:
| Ethernet can handle real time now even in bus
| configurations!
|
| 10BASE-T1S is a new standard geared for automotive. It uses
| physical layer collision avoidance instead of classic
| Ethernet exponential backoff. This provides deterministic
| maximum latency.
|
| Though you can get max latency guarantees with switched
| Ethernet and the appropriate switch QoS and hardware.
| m463 wrote:
| I'll bet a hidden factor here is development and testing.
|
| They can probably develop for a car ethernet lan with a
| desktop pc and car "peripherals".
|
| Not that there aren't canbus cards for pcs, but still.
| numpad0 wrote:
| This sounds like the real answer. Replacing an automotive
| standard with Ethernet is going to reduce friction
| onboarding junior webdevs with MacBooks, and enable a more
| stable higher turnover labor intensive organization.
| maxerickson wrote:
| CAN to PC adapters are a few hundred dollars, it isn't
| causing much friction.
| m463 wrote:
| With ethernet you can probably run the car software in
| containers.
|
| I can imagine a container to simulate each hardware unit,
| a small inter-contaner lan, and develop code that way.
| soco wrote:
| Reminds me when my Opel resetted itself while driving on
| the highway. Oh, the adrenaline...
| dpeckett wrote:
| You can already do this trivially with Linux vcan[1] so I
| don't buy this argument.
|
| I think the bigger factor is that innovation in the CAN
| ecosystem has been lagging behind Ethernet for decades
| now. Only reason it's had such staying power is industry
| inertia.
|
| 1. https://netmodule-
| linux.readthedocs.io/en/latest/howto/can.h...
| maxerickson wrote:
| The relative cost is probably a factor (which overlaps
| with inertia of course, but if the thing you already have
| implemented is also cheaper, you aren't going to hurry up
| and change).
| JoshTriplett wrote:
| CAN has desirable electrical properties (e.g. hardware-level
| prioritization) if you have life-critical devices and non-
| life-critical devices on the same network. But it's painful
| to deal with from a software point of view, compared to IP-
| based protocols, for anything that doesn't _require_ the
| properties of CAN.
| cyberax wrote:
| Industrial Ethernet (PROFINET) also has priorities and
| bandwidth reservation: https://en.wikipedia.org/wiki/Profin
| et#Technology_of_Class_C...
| throw0101d wrote:
| > _Tesla really deserves some kudos for pushing the 48V
| architecture and the Ethernet-based communication._
|
| For the record, 42V systems were experimented with in the
| 1990s:
|
| * https://en.wikipedia.org/wiki/42-volt_electrical_system
|
| In the 2011 German automakers agreed to 48V as the next step
| after 12V:
|
| * https://en.wikipedia.org/wiki/48-volt_electrical_system
|
| BMW was the first the first with Ethernet:
|
| * https://www.marvell.com/blogs/the-right-stuff-a-past-and-
| fut...
| iknowstuff wrote:
| none of them actually shipped a mass market almost
| exclusively 48V product if you're trying to imply tesla's
| push isnt as massive as it is.
| cyberax wrote:
| This has been a real head-scratcher for me. BMW and other
| automakers could have vastly improved their cars by switching
| to 48V a decade ago, but they still keep just plodding along
| with 12V.
|
| I have no explanation for this.
| theshrike79 wrote:
| Tradition, long supply chains etc.
|
| Tooling all their shit to 48V is a massive undertaking with
| pretty much zero advantages.
| cyberax wrote:
| They don't need to retool all the factories at once. They
| could have gradually introduced 48V systems in parallel
| with 12V, slowly phasing in new components as they
| replaced the old 12V.
| typewithrhythm wrote:
| Converting between voltages is not a free action, and
| running two systems is more complicated than one...
|
| You really need some special component that is much
| better at 48 for it to be worth it, otherwise a delayed
| platform switch is better; one some competitors have
| moved and the suppliers exist.
| Kirby64 wrote:
| The special component was supposed to be the starter.
| With start stop systems essentially mandatory, the
| starter runs much much more often and therefore wiring
| savings on the starter are pretty useful...
| cyberax wrote:
| Starter motor, power steering, heated seats, powerful
| headlights, power-hungry onboard computers.
|
| They _all_ benefit from 48V.
| shiroiushi wrote:
| On top of all that, almost _all_ the wiring in the car
| can be made thinner, because of the greatly reduced
| losses. This saves a bit of weight, but also a _lot_ of
| cost because copper is expensive.
| potato3732842 wrote:
| There is no free lunch. You need to go to a finer wire
| strand, better insulation, better loom, better support
| for the harness etc, if you want that super fine wire to
| last. Some of those have pretty direct labor cost impacts
| too. That's gonna kill a lot of your cost savings,
| especially at lower production volumes where the design
| cost is harder to amortize. There's no free lunch.
| msandford wrote:
| > better insulation
|
| It's very, very hard to get insulation that's not good
| for at least 100V and I suspect that just about any
| generic wire is good for more like 300V.
|
| The only exception that comes to mind is wire that's
| specifically for "household low voltage" like 24V AC for
| thermostat, doorbell, sprinklers, landscape lighting.
| Also normal ethernet. But these are almost all what you'd
| call signalling wiring rather than power wiring.
|
| Your average hook-up wire that you could buy at the auto
| parts store to make some repairs is almost certainly
| rated for 300V already. Mostly because of chafe
| resistance. Wikipedia says that the dielectric breakdown
| strength of PVC is 40 millions volts per meter
| https://en.wikipedia.org/wiki/Polyvinyl_chloride.
|
| Divide both sides by 1 million and you get 40 volts per
| micron. OK so you need 1/3 of a micron to insulate enough
| for 12V and you need 1.25 microns for 48V. Now let's have
| a reasonable safety factor of say 10 or so and we're
| looking at 3 microns vs 12.5 microns. The only wire I can
| think of that might have insulation that thin is enamel
| coated magnet wire for the inside of motor windings. But
| even that is probably thicker.
|
| Any kind of plastic insulation is going to be
| significantly thicker than this just to be able to be
| coated onto the bare copper wire and stick.
|
| You're not wrong that the insulation needs to be thicker
| as the voltage goes higher. But you're unaware of just
| how ridiculously over-insulated everything already is due
| to other constraints of manufacture.
| potato3732842 wrote:
| I was talking about the structural side of things, not
| the electrical side. I thought this was fairly obvious
| but I guess not.
| numpad0 wrote:
| I'm sorry but the other comment is more correct. 48V
| standard was originally created for mild hybrid systems
| for ICEs during mid-2000s as a _stopgap solution to full
| hybrid transition_. Looks like the earliest mass-
| production 48V-class system was a 2001 Toyota that ran at
| 36V.
|
| The integrated starter generator(ISG) is usually a
| pancake shaped motor that replaces clutch/torque
| converter in ICE car, nothing like the regular starter
| motor.
|
| MHV was not even real hybrid, and is no longer relevant,
| so was 48V, at least for a while.
| vardump wrote:
| Less copper in the car is not a "zero advantage". Cheaper
| and lighter.
| m463 wrote:
| I think it's like any existing vs new tradeoff.
|
| Tesla didn't have any existing, so their clean-slate math
| was clearly in favor of 100% new technology.
|
| (Well, they did have 12v existing in their other cars, but
| they were clean-slate in the truck.)
| numpad0 wrote:
| care to define "improve"...?
| cyberax wrote:
| More robust, cheaper (far simpler wiring harness),
| eventually ability to do zonal assembly.
| numpad0 wrote:
| Are BMW cars less reliable, expensive, not ready for
| zonal assembly...?
|
| Major car components like doors or front axles are
| assembled in parallel to miscellaneous parts on the main
| body, and all .join() at the final assembly. This had
| been the case for past 30-50 years, possibly more, in
| case this needs to be said.
| cyberax wrote:
| They can be even more reliable. And they definitely _are_
| expensive.
|
| > Major car components like doors or front axles are
| assembled in parallel
|
| And doors (and tailgates) are the biggest body component
| that is _sometimes_ assembled independently. Then workers
| manually route cables through the body.
|
| Pre-routing cables inside panels that can then just be
| welded together can save a lot of labor.
| numpad0 wrote:
| > And doors (and tailgates) are the biggest body
| component that is _sometimes_ assembled independently.
|
| Sometimes? What and when on Earth is this about? Pre-
| WWII?
|
| They wash and paint and dry the whole body at once _for
| paint consistency_, then take off doors and trunk lids
| and bumpers and send them into separate assembly lines.
| Those major parts flow parallel "threads" in sync and
| converge near the end, where connectors are plugged in
| and those major parts are bolted back in and plastic
| trims are pushed in to tuck everything under. Cars were
| basically always done that way for a long time
| everywhere. I think even lots of hand made supercars are
| like that, only except tact times are magnitudes longer.
|
| > Then workers manually route cables through the body.
|
| > Pre-routing cables inside panels that can then just be
| welded together can save a lot of labor.
|
| What do these even mean? Are you hallucinating workers
| crimping cables in-situ? They just clip on harnesses and
| plug in couplers in "the line". Never seen under a door
| trim?
|
| It sounds like you're either extremely ill-informed, or
| worse yet, potentially, intentionally misinformed about
| car manufacturing that what you see is advanced
| manufacturing. I think you should... look more closely
| into what "legacy auto" have been doing forever.
| cyberax wrote:
| > What do these even mean? Are you hallucinating workers
| crimping cables in-situ? They just clip on harnesses and
| plug in couplers in "the line". Never seen under a door
| trim?
|
| Workers still need to pull the wiring bundles through the
| car body and clip them, after the body is welded
| together. The connectors are impractically bulky to put
| several of them along the cable routes.
|
| Pre-assembled panels can have cable runs attached to them
| during the individual panel assembly.
| phlipski wrote:
| It's a classic chicken and egg economic problem. BMW
| doesn't make the chips/electronics that support the 48V
| architecture - Bosch & Continental (with
| NXP/TI/Infineon/Renesas as their silicon suppliers) do and
| they're not going to support 48V unless ALL (or a
| significant majority) of the automakers will. So it's a
| game of chicken.
| maxerickson wrote:
| The semiconductors have been available for 20 years.
| michaelt wrote:
| Eh, yes and no.
|
| I designed some stuff along these lines 15 years ago. At
| that time, 12 volt stuff was not just available, it was
| available with great economies of scale and a huge range
| of options, off the shelf. You need an automotive-
| qualified relay? A light? A solenoid? A DC-DC converter
| module? A fan? You'd have 100 choices at 12v, 30 choices
| at 24v and 3 choices at 48v.
| MuffinFlavored wrote:
| > BMW was the first the first with Ethernet:
|
| BMW ENET is non-standard, DoIP is standard. :)
| saturn8601 wrote:
| You'll be sorry when this move further hamper repair efforts
| and the TCO of owning a vehicle goes up.
| porphyra wrote:
| You can say that about any new standard. With that logic we'd
| all be stuck with knob and tube wiring.
| ElevenLathe wrote:
| Did cars ever use knob and tube?
| porphyra wrote:
| Not that I know of --- it's a figure of speech to compare
| it to an standardized method of electrical wiring in
| buildings that eventually got replaced with better
| standards despite similar concerns at the time.
| bluGill wrote:
| Well technically a spark plug is the tube part.
| jeffbee wrote:
| How about comparing it to a teardown of a Rivian? Rivian uses
| 2-wire ethernet but 12V, so it seems like a more interesting
| comparison.
|
| That said, it all seems like inside baseball to me. The BMW
| 850i pioneered the CAN bus, but that car was forgettable and
| although CAN bus took over the car industry that did not seem
| to create any durable advantages for BMW.
|
| Ethernet seems like the inevitable replacement for CAN, in
| light of VW's investment in Rivian, and 48V vs. 12V for the
| low-voltage systems seems like a wash.
| two_handfuls wrote:
| With the appropriate grain of salt due to the source,
| standardizing those power connections would probably be a good
| thing.
|
| Also, speeding up the adoption of 48V, the industry has been
| talking about it for so long!
| zaroth wrote:
| Grain of salt due to the source? What is that supposed to mean?
|
| Tesla is so far ahead when it comes to these things (48V
| architecture), there literally is no other source in this case.
| sixQuarks wrote:
| There is so much Elon and Tesla hate, these comments are so
| weird.
| xyst wrote:
| > Today a single vehicle typically requires over 200 connections
| --and the number of electrical
|
| I initially thought this was referring to the connector between
| the charge port on the EV and the charger base station. Had to
| think for a second and realized it's the electrical connections
| between the various components in an EV.
|
| Glad to know I don't have to carry 200+ dongles in case I buy an
| EV.
| HPsquared wrote:
| That must be only the high voltage connections, right?
| atonse wrote:
| These are talking about 48V, so my guess is it's for all the
| little bits (window motors, wipers, all the internal
| electronics, switches, turn signal lights, etc etc)
| HPsquared wrote:
| To be honest I'm kind of surprised by the low number.
| Though I guess each connector has two sides, and they can
| have tens of pins per connector on the bigger ones.
| connicpu wrote:
| (Semi-permanent) High voltage connections are usually made
| with spec-torqued bolts, not plastic connectors. These are
| for the "low voltage" (<=48V) components spread throughout
| the vehicle.
| xpe wrote:
| Just to clarify, the linked article about the LVCS connector is
| for internal electrical cabling, not for electric-vehicle
| charging. For Tesla's charging standard (SAE J3400), see
| https://en.wikipedia.org/wiki/North_American_Charging_System
| nimbius wrote:
| why not use the Chinese standard, GB/T?
|
| china has the most electric cars, the largest manufacturers, and
| the most advanced battery production on the planet. their
| experience with electric vehicles and charging would be a
| valuable leap forward.
| BrianGragg wrote:
| The GB/T is for charging and not in car connections. Tesla
| already has an arguably better connector NACS or J3400 now.
|
| As for China having the most electric cars on the planet. I
| don't feel that makes them the experts. China tends to steal /
| copy technology from other countries and has little innovation
| them self from my view point. They have the most EV's from
| heavy government subsidies. Tons of cars in graveyards over
| there.
| iknowstuff wrote:
| lmao are you a bot? this is not about charging connectors, and
| GB/T (with its two separate connectors for AC and DC) is awful
| compared to NACS.
| Aloisius wrote:
| How is this better than all the other 48V connectors out there
| (MX150, MCON, PP, etc.)?
|
| Surely it isn't just that they reduced the number of connectors
| since one could have just standardized on a subset of mass-
| produced connectors by molex, te, etc. instead.
| riskable wrote:
| I'd like to know this too. Their website claims "cost" but
| doesn't actually list the costs of the new connectors compared
| to existing ones.
|
| At least give us some comparisons!
| Animats wrote:
| Those look much like AMP automotive connectors.
|
| Using one kind of unkeyed connector in a car may be a bad idea.
| Things can be plugged in wrong during repairs. There's a lot to
| be said for making connectors not fit where they shouldn't.
| Especially in automotive, where many connectors are plugged in
| blind, by feel. This simplifies manufacturing at the cost of
| repair.
|
| If it can be plugged in wrong, it will be plugged in wrong. AAA
| put a battery in backwards in my Jeep once, and most of the
| vehicle electronics had to be replaced.
| themaninthedark wrote:
| These looked keyed to me. Aside from the bulge on the top of
| the connector where the lock attaches to it's mate there is a
| middle vane that extends 2/3 way down with a little bit of a J
| hook on it.
| Animats wrote:
| That's the latch, not a key. Keying prevents putting the
| wrong plug in a receptacle. Usually that's done with notches
| on the receptacle and ridges on the plug.
| themaninthedark wrote:
| You can use the ridge that the latch attaches to as part of
| the key structure.
|
| There is also a J-shaped structure inside the plug that
| would function as a key as well, prevents the plug from
| starting when rotated 180 degrees. ==
| ------ | | | | / | ------
| cduzz wrote:
| I think by keyed it isn't just "can't be plugged in upside
| down" but _also_ "can't be plugged into the other plug that's
| basically the same but connects to some other subsystem."
|
| Ideally a system like this would let you select some per-
| subsystem physical lockout mechanism.
| taneq wrote:
| Have they said there isn't a mechanism for individually
| keying connectors? There might be something optional, even
| if it's just blanking pins.
| numpad0 wrote:
| Connectors with distinct shapes and sizes are usually
| used. If it feels like it could go in then it's the right
| one, and if it goes in it easily seats fully and never
| comes out without a tool. Wrong connectors don't even
| feel like they could go into wrong locations.
|
| Cars using whole bunch of different connectors relying on
| whole bunch of suppliers is feature-not-bug situation. It
| is optimal for large scale volume production; work will
| be more distributed, SPoF will be more localized, etc.
| Standardized connectors with trivial visual differences
| and/or field configurable keying is a suboptimal solution
| for car problem. Usually.
|
| ...is it a local minima for small scale production? Are
| they having issues with scale outs, and therefore seeking
| _downward_ scalability?
| taneq wrote:
| I work in this space and 100% agree, in fact I have been
| on a bit of a crusade to get the mechanical guys to stop
| designing parts that are rotationally symmetric for this
| exact reason. Letting a set of three parts be installed
| 17 different ways isn't "keeping our options open" it's
| "fucking up maintainers." Each part should fit exactly
| one obvious place. Each connector should plug in at
| exactly one obvious place. The only exception is when it
| doesn't matter where the part goes, which is
| approximately never.
|
| That said, sometimes there are cases where an entirely
| new connector style isn't warranted, and that's where you
| use blanking pins or adjustable keyways or whatever.
| themaninthedark wrote:
| That level of keying would be done at the
| harness/electrical engineer level. You shouldn't put two
| same plug ends at one termination site.
|
| You really couldn't control it at plug or part level.
| theamk wrote:
| It has to be both.
|
| The plug manufacturer has to provide many, many keying
| options (say for a 2-pin plug, one might have variants
| 2A, 2B, etc... which explicitly cannot mate with each
| other)
|
| An engineer designing the car has to ensure all plugs
| with same keying options are interchangeable (2A is for
| power supply; 2B for door switch; etc...)
|
| If the plug manufacturer does not provide enough keying
| options, this will be pretty hard to during design time.
| themaninthedark wrote:
| You are generally not using just one plug style on a
| harness so most of the control is at the engineer level.
|
| Unless you are a big player, what plugs you are using
| boils down to what receptacle the component that you want
| to attach to use.
| black6 wrote:
| One of my takeaways from my time as a RATELO is the thought put
| into connector design. Everything in the Army was designed to
| plug into one thing and one thing only to prevent mistakes.
| viraptor wrote:
| > Using one kind of unkeyed connector in a car may be a bad
| idea. Things can be plugged in wrong during repairs.
|
| I tried to lower the window in a Ford shortly after leaving the
| dealer. It fried the lock. Somehow they were connected together
| by accident. I agree dumb wires should be hard to mix up like
| that - both via orientation and similarity.
| maxerickson wrote:
| At least reverse battery protection is pretty standard these
| days.
|
| Doesn't make things work when they are plugged into the wrong
| connector, but they should still work once the connections are
| straightened out.
| Animats wrote:
| There's no excuse for that any more, especially since the
| invention of the ideal diode.[1]
|
| [1] https://www.ti.com/lit/an/slvae57b/slvae57b.pdf
| elcritch wrote:
| Actually there's two paths: first the traditional path of
| different unique wiring harnesses and various signals with
| unique connectors, or second a common power and coms bus
| design.
|
| If the Cybertrucks electrical ethos is followed by others
| there's only 48V and Ethernet. Ethernet doesn't care or fry if
| plugged into a wrong port. Any complex wiring can be done
| inside a part or component as needed, but the interface is one
| of a few options.
|
| Let's say the window motor is plugged into the power and not
| the switched motor plug. As long as it's a 48V motor it'll just
| turn but not fry. You just unplug it and reconnect it.
|
| IMHO industrial everything should become 48V Ethernet. Just
| like for gadgets usb-c rules the roost.
| michaelt wrote:
| _> If the Cybertrucks electrical ethos is followed by others
| there's only 48V and Ethernet._
|
| I'm looking at the electrical schematic [1] and 'eth' appears
| 107 times while 'CAN' appears 805 times.
|
| And if you think about it, you probably don't want your
| brake-by-wire system to share a bus with your sound system
| and your trunk latch for obvious reasons.
|
| [1] https://service.tesla.com/docs/Cybertruck/ElectricalRefer
| enc...
| aeonik wrote:
| What are the obvious reasons?
| Glawen wrote:
| Denial of service of the bus due to a bug or electrical
| malfunction
| aeonik wrote:
| I thought the discussion was on context of CAN vs
| Ethernet.
|
| These two are still vulnerabilities with Ethernet.
| solarkraft wrote:
| Different quality of service requirements. The
| infotainment system is complex and it failing is just
| annoying while the brake failing could mean _death_.
| elcritch wrote:
| Cool, thanks! It looks like the cybertruck does extensively
| use CAN still. Tesla only talks up Ethernet.
|
| Makes sense, though I'm a bit bummed.
|
| > And if you think about it, you probably don't want your
| brake-by-wire system to share a bus with your sound system
| and your trunk latch for obvious reasons.
|
| Sharing a bus for those two wouldn't make sense. However
| Ethernet topology wouldn't preclude having those on
| separate buses and linked via switches.
|
| Though that'd pose problems with my view above about
| plugging anything in anywhere. Though it's really more of a
| philosophical goal. ;)
| HeyLaughingBoy wrote:
| > However Ethernet topology wouldn't preclude having
| those on separate buses and linked via switches
|
| The topology might not care, but someone designing a
| trunk latch that communicates via Ethernet might get a
| visit from an annoyed representative from Value
| Engineering.
| elcritch wrote:
| Haha touche. However unintuitive as it may seem an
| ethernet based trunk latch could be overall cheaper from
| a system level than a straight relay based system or even
| CAN system.
|
| Especially with the newer two wire ethernet with power
| via 10BASE-T1S. The connector likely costs more than the
| ethernet chip, and microprocessors can be had for
| nickels. So at large manufacturing scale it could easily
| cost less to share a single ethernet and power line and
| save on wiring, connector complexity, etc.
| Aloisius wrote:
| Even Cybertrucks aren't purely 48V and ethernet.
|
| There's a high voltage (800V) rail for high current devices
| like the AC compressor. There's redundant CAN for
| communication with things like the motors. There's a host of
| 12V, 16V, 5V components (door locks, lights, seat motors,
| etc.).
|
| They did switch many components to 48V, but not literally
| everything.
| jiveturkey wrote:
| Nah, these look like keyed Deutsch DTM connectors. They are
| very obviously keyed, so not sure why you say unkeyed.
|
| This will never take hold. These are extremely expensive vs
| weatherpack and other cheap connectors. Auto manufacturers care
| about literal pennies.
| inferiorhuman wrote:
| Well that's a lot to unpack. Saying AMP connectors doesn't
| really mean much of anything because, for starters, AMP (TE
| Connectivity) owns Deutsch.
|
| In the retail space, at least, DTM's largely been superseded
| by the lower-cost ATM line. Weatherpack and Metripack are
| pretty common in the US because GM developed them and GM is a
| huge company. The only company that comes to mind for using
| DTM connectors is Caterpillar, so you'll definitely see
| medium duty trucks with DTM assemblies.
|
| The two automotive companies I'm most familiar with (80s
| Volvos and 00s BMWs) use keyed connectors all over the place.
| The Volvos used off-the-shelf washing machine connectors (AMP
| /(junior )+(power )+timer/) that can be had with keyed
| connectors. BMW saved pennies by going with high density
| connectors and small gauge wire. Most of that stuff is off-
| the-shelf as well, but often with proprietary keying.
|
| Both DTM and Weather/MetriPack are pretty bulky compared to
| what's available now though, and when you're talking about
| 100 or 200 pin connectors size probably matters more than a
| few pennies. And, of course, once you start adding the
| retention doodads to MetriPack assemblies you start getting
| closer in price to DTM style stuff. The simplicity of the
| wedgelock design means fewer parts to stock and potentially
| faster assembly which could easily negate the more expensive
| housings.
| hatsunearu wrote:
| there is utility in this.
|
| the motorsports world generally has converged to exactly two
| connectors:
|
| DT series connectors and AS series connectors. The former is made
| of plastic and very robust. The latter is made of metal and is
| extremely robust.
|
| It's nice having to just have a bunch of DT parts and just be
| good to put it in everything.
| Animats wrote:
| What's the signal connection? Does this use CANbus? Ethernet?
| What?
| sanex wrote:
| Someone's going to post this eventually may as well be me I
| guess. https://xkcd.com/927/
| 7thpower wrote:
| Molex and others may as well get behind this. EVs are driving all
| the content (as you can imagine, electric vehicles are way more
| profitable than IC not only because they have additional
| connectors but also because they tend to have more advanced in
| vehicle entertainment).
|
| The other reality is that all of the Chinese OEMs will generally
| work with the companies like Molex, TE, Amphenol, etc just long
| enough to let them shoulder the R&D cost and then reverse
| engineer and vertically integrate the part in their supply chain.
|
| If there is a chance to leverage their scale and supply chain to
| compete where there is known demand, it's worth it to be early in
| and then be able to help OEMs customize the reference designs as
| needed.
| BerislavLopac wrote:
| Judging just by the title (and without noticing the source), I
| was hoping that this will be about standardisation of the vehicle
| metrics data via OEM sources. Last year I worked on a system that
| collects this data, and currently each OEM has a different method
| (sometimes several, for different message types) it can use to
| share it with the wider world.
| incorene wrote:
| There are already MANY standard types of connectors that
| automakers don't use consistently, why add another one to the
| mix? What does this offer that Deutsch or Weatherpak don't?
|
| XKCD summed this up pretty well: https://xkcd.com/927/
|
| Besides that, I have no respect for Tesla. They can't engineer
| their way out of a paper bag, they are hostile to both the
| customer and the rest of the industry, and notoriously so in
| terms of repairability--why would I believe that now they
| suddenly care about designing a better, more universal connector?
| They don't even make repair parts available to the consumer!
|
| For those reasons and many more, the absolute LAST thing I would
| ever do as an engineer is to buy into a standard set by Tesla, or
| any other company run by Elon Musk.
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