81–90 of 107 posts
What devices are left that are fairly normal (that normal people might interact with in a given week), mechanical or electromechanical, have at least modest complexity, and have no microchips? Locks? Guns? What else? EDIT: perhaps an extra requirement that it's fairly durable, i.e. easily lasts ten years of normal use. EDIT2: maybe it should also fit the requirement that it's a current model in production and that yo…
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In low temperatures you start having issues with moisture saturating the air. Things get wet out of nowhere. There are also electrolytic capacitors which are water based so these need to be ruled out as well. Given air has at any given time a lot of water and water goes through a phase change at sub zero i find the comparison quite invalid.
That's a difference with automotive/aviation products. They will all be in sealed containers and then the actual circuitry will all be covered in plastic. There shouldn't be any exposed metal that could possibly short, even if immersed in water. Pouring buckets of water on a running engine (ie a gap in the hood closure on a rainy day) or even into the passenger compartment (ie sunroof left open) shouldn't do much of…
B6 Audis have a design problem with their sunroof drains. When they clog up, unknown to you, the water will pool in passengers footwell area. It takes a while to notice this as a person, as there is 4-6" of foam padding between the metal floor of the car, and where you rest your feet . The TCM lives between these layers, and eventually, in the lake that will form, submerging your TCM -- leaving you with yet another reason to hate your Audi.
This is early 2000's. Late 200* a8 models had I believe 30+ different "computers" living in the same over metal under foam situation.
An aside, if you ever wash the engine bay of a car with low pressure water, I'd suggest covering the blatant electronic bits with some plastic bags, and leave the car idling when you do so -- that way if/when it starts to sputter or just dies, you have a general idea of where it all went wrong.
They really are not as water tight as we all assume.
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Sounds a bit like BMW’s VANOS or Honda’s Vtec. Variable cam timing is super cool tech and a huge reason newer cars are so much faster than old cars.
If described correctly, it is a different concept. Variable cam timing in the context of VANOS / Vtec / VVT refers to variable timing on the camshaft that controls valves. This sounds different, and I think it refers to mechanical fuel injection. Several automakers experimented with mechanical fuel injection in the 80's and early 90's, but I think the concept died pretty quickly. It was rather complex, failure prone,…
Thing is, mechanical FI is almost as hard to tune for emissions and economy as carburetors, so electronic control is necessary.
Chrysler offered an EFI system based on the Bendix Electrojector in '58, but the tech was not fully baked, for one thing, the electronic controls were vacuum tubes in an enclosure in the dash; I think there may be one remaining operational '58 Imperial with that system still running....
Anyway, Bendix sold the patents for the Electrojector to Bosch, which a decade later had developed them into the J- and K- Jetronic transistorized throttle-body EFI systems so beloved by Porsche 914 enthusiasts.
From the article: > Mobile phone SOCs integrate a substantial amount of function right onto the chip. Why hasn’t that been the case for the car? Because your mobile phone SoC is not certified for -20/+80 degrees Celsius, copious amount of vibration, error-free operation on many environments (incl. inputs with wrong voltages, shorts, etc.), and have a lifetime of 10+ years with the same performance characteristics. Yo…
Lets not exaggerate :) ECU reads a bunch of sensors, does some mild compute, uses that to do a table lookup, interpolates and slaps the result into actuators. 8bit 10MHz is enough to accomplish this task.
> Automakers found that mechanical, hydraulic or pneumatic controls failed to achieve enough accuracy and consistency over each vehicle's usage life to meet these emissions tests. This was especially the case as the car aged. Decades ago, I owned an old Alfa Romeo that incorporated a complicated cam system to control the oxygen ratio to the fuel injection system. More complex than your typical 1-dimensional function…
>Decades ago, I owned an old Alfa Romeo that incorporated a complicated cam system to control the oxygen ratio to the fuel injection system. More complex than your typical 1-dimensional function of a cam, this cam was "two-dimensional" in its output. The cam follower was able to slide along the axis of the cam based on something or another (RPM? temperature?) and the profile of the cam varied from one end to the othe…
From the article: > Mobile phone SOCs integrate a substantial amount of function right onto the chip. Why hasn’t that been the case for the car? Because your mobile phone SoC is not certified for -20/+80 degrees Celsius, copious amount of vibration, error-free operation on many environments (incl. inputs with wrong voltages, shorts, etc.), and have a lifetime of 10+ years with the same performance characteristics. Yo…
Well, it takes some parameters, goes into a lookup table and decides how much timing to retard, or fuel to give, and probably has a o2 sensor, checks knocking, etc. All done on pretty barebones 80's tech.
What devices are left that are fairly normal (that normal people might interact with in a given week), mechanical or electromechanical, have at least modest complexity, and have no microchips? Locks? Guns? What else? EDIT: perhaps an extra requirement that it's fairly durable, i.e. easily lasts ten years of normal use. EDIT2: maybe it should also fit the requirement that it's a current model in production and that yo…
Interesting question. * it's surprising how many dishwashers still use spring-loaded timers to sequence their operations. Although at this point mine is 19 years old so maybe that doesn't count. * Likewise, my iron filter is sequenced by a mechanical timer (run off an electric motor), but my water softener's controller is fully electronic. * A lot of houses still have mechanical mercury thermostats. * The flush valve…
yeah, the houses that have heat. ask an HVAC guy about the new digital thermostats. I'm not even talking about the Nest etc. smart home ones, just the basic new digital ones that croak after three years. Keep the mercury-switch ones as long as you can.
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SpaceX works around that by using consumer grade stuff and just replicating it 3 times. Tesla also managed to handle issues with supply shortages very well. The old practices are just not good enough.
> The old practices are just not good enough. True, but also think about the path dependence of the old companies. They have withered a lot of ups and downs, they are not the innovators, they are the very slow incrementalists that despite this release a new boring model every few years dressed up as the new best thing ever. (If you have seen a car from one manufacturer you have seen them all from them for the past de…
This article does a good job outlining why these systems can't just be replaced with a Raspberry Pi or an Arduino: Durability. At one point I was interested in replacing the ECU in my old '88 Suburban. The ECU is probably the only "real" bit of electronics in the whole vehicle. And yet after almost 35 years it's still doing fine. The Arduino based ECU I was looking into, as it turns out, is a great hobby project, but…
Well sorta, turns out the 88 is far more reliable and consistent - except for a few hard to find parts... namely the distributor is a total piece of crap after that many years... and it's not very efficient. I get 50% more performance and 50% more gas milage on the uprated one.
Difference in reliability is probably... once every 25k versus once every 50k though.
Those bosch systems were all over volvo, saab, porsche, VW, Audi, etc and are dead reliable but not very hackable.
> It would be a misconception to look at your standard internal combustion car as a fundamentally mechanical device. Today's cars are some of the most complex electronic systems mankind has ever made. As a car restorer, mechanic and enthusiast, yes. This is also why bringing a car in for service has ballooned in cost over recent years. Oddly, it’s become remarkably _easy_ to chase down a problem in a car because the…