electronic throttle
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From: DAS on 9 Mar 2010 10:56 I stand corrected. I checked a pukka source. I now agree with you... (I had been thinking of gelatine in particular). DAS To reply directly replace 'nospam' with 'schmetterling' -- <clare(a)snyder.on.ca> wrote in message news:aq6bp598lr58emvvjv56u9bfas17aci0cr(a)4ax.com... [...] > Both Jelling and Gelling are correct english usage. > Jell- > to become clear, substantial, or definite; crystallize: The plan began > to jell once we all met to discuss it. -verb (used with object). 3. to > cause to jell. ... > [...]
From: cuhulin on 9 Mar 2010 11:49 I will never buy a drive by wire vehicle of whatever brand name.I don't need nor do I want that. cuhulin
From: clare on 9 Mar 2010 13:21 On Mon, 08 Mar 2010 19:47:23 -0500, clare(a)snyder.on.ca wrote: >On Mon, 08 Mar 2010 06:14:04 -0500, Bill Putney <bptn(a)kinez.net> >wrote: > >>clare(a)snyder.on.ca wrote: >>> On Sun, 07 Mar 2010 18:29:44 -0500, Bill Putney <bptn(a)kinez.net> >> >>>> Actually, after some thought, I can see how it might be done with a >>>> single pot: Pot wiper gets tied to ground, and you run constant current >>>> into each end terminal. The voltages read at the two end terminals will >>>> be inverse of each other (as wiper is moved in one direction, voltage of >>>> one end terminal goes from 0 to R x I, voltage of the other end goes in >>>> the opposite direction). >>>> >>>> Not saying that the designers would have realized that it could be done >>>> like that, but that's the only way I could think of using a single pot. >> >>> That works too. >> >>But my way violates the unacceptable ground on an analog input that you >>pointed out. Your method is better. >> >>BUT - you wouldn't even have to raise the ref and its ground. Kind of >>combine our two methods: Tie the wiper to the ref. voltage (gets rid of >>the ground issue), and put a constant current source (sinking) on both >>ends. Scale your constant current and size your pot. such that when the >>wiper is pegged to one end (and reading 5 volts), the voltage on the >>other end is, say, 1 volt. That could be done with a nominal 8 mA >>current source and 500 ohm pot, as an example. The two ends would range >>between 1 and 5 volts (nominal), and be inverse of each other. One >>check the ECM could do is verify that the two voltages at any moment in >>time add up to 6 volts. > > >Quite pssibly how they do it - I was just showing a "simple" example. I got a LOT more information on how Toyota REALLY does it. I'll share later tonight.
From: clare on 9 Mar 2010 13:27 On Mon, 08 Mar 2010 19:10:51 -0800, jim beam <me(a)privacy.net> wrote: >On 03/07/2010 03:14 PM, clare(a)snyder.on.ca wrote: >> On Sun, 07 Mar 2010 13:39:08 -0800, jim beam<me(a)privacy.net> wrote: >> >>> On 03/07/2010 12:42 PM, Bill Putney wrote: >>>> jim beam wrote: >>>>> On 03/07/2010 09:44 AM, Bill Putney wrote: >>>> >>>>> then you're making generalizations from your own exceptional >>>>> experience that are not representative of most vehicle, and certainly >>>>> not vehicles with standard tuning. vacuum decreases significantly at >>>>> w.o.t, is sufficient to give brake boost. >>>>> >>>>> besides, how much vacuum do you think you need for a brake booster? >>>>> with a 9" diameter diaphragm, [on the small side by modern standards], >>>>> that's 63 sq inches. how much pressure delta do you think you need to >>>>> double a person's braking force? >>>> >>>> You'd have to know the mechanical advantage in the pedal from basic >>>> lever math and a bunch of other stuff that is beyond what either of us >>>> wants to get into here. Without the absolute numbers for all that stuff, >>>> it suffices to ratio things: When the booster is designed to properly >>>> operate at 7 times the vacuum that you'll get from an engine under >>>> acceleration, I say your assist is going to be close to useless >>> >>> how did you manage before the days of vacuum assist? >>> >> >> Before the days of vacuum assist, master cyls had larger pistons > >other way around - longer travel results from smaller piston diameter, >not larger. Brain fart - you are correct > > >> and >> pedals had longer travel, providing more mechanical advantage. > >more m.a. comes from smaller pistons. at the price of longer travel. > > >> In most cases they also had self energizing (servo action) drum >> brakes, which provide SIGNIFICANTLY more initial brake effectiveness >> than disc brakes (but suffer much more from temperatire induced fade) > >self-servo is a significant problem and one brake manufacturers went to >lengths to avoid. it's great for parking brakes and automatic >transmission clutches of course, but service brakes need to be as linear >as possible to avoid unintended lockup. Virtually ALL american cars from the mid fifties on used self actuating, or SERVO brakes. Bendix being the premier example. All but killed the Huck, center-plane, and twin leading shoe brake systems in America, and most of the rest of the world.
From: clare on 9 Mar 2010 13:29
On Mon, 08 Mar 2010 19:29:18 -0800, jim beam <me(a)privacy.net> wrote: >On 03/07/2010 09:27 PM, Jim Warman wrote: >> Actually, in the modern automobile, the gas pedal tells the PCM that you >> want to go faster... >> >> A lot of you folks are gong to be disappointed in the near future... >> >> The headlight switch tells the BCM that you want to turn on some lights... >> the turn signal switch tells the BCM that you wnat to turn on some flashing >> lights... >> >> This is gonna be cool... > >don't german cars already do this? one power line, one signal line, and >reader/switch modules on each light? > > >> Not just German - but BMW is in for the lang haul. It's called CanBus >> >> "Jeff Strickland"<crwlrjeff(a)yahoo.com> wrote in message >> news:hmuep4$qd2$1(a)news.eternal-september.org... >>> >>> "jim beam"<me(a)privacy.net> wrote in message >>> news:uqOdnfZrX4eWKQ_WnZ2dnUVZ_qIAAAAA(a)speakeasy.net... >>>> On 03/06/2010 09:03 AM, Jeff Strickland wrote: >>>>> "jim beam"<me(a)privacy.net> wrote in message >>>>> news:fvudnV-hwr-Z6A_WnZ2dnUVZ_rednZ2d(a)speakeasy.net... >>>>>> if you buy all this fear-mongering idiocy that electronic throttle is a >>>>>> problem, and that brakes, transmissions and ignition kill switches can >>>>>> all >>>>>> simultaneously fail causing a driver to lose control, it might be worth >>>>>> auto manufacturers of all stripes to adopt a slightly different >>>>>> implementation of electronic throttle [e.t.] - if not for mechanical >>>>>> reasons, but to shut the idiots up. >>>>>> >>>>>> first, lets understand e.t. functionality: >>>>>> >>>>>> 1. open the throttle when demanded >>>>>> 2. close throttle when demanded >>>>>> 3. allow "demand" to account for additional requirements like >>>>>> a. de-throttle on shifting for automatics, >>>>>> b. throttle appropriate to load at high demand [eg. full throttle at >>>>>> low >>>>>> rpms can choke an engine and significantly reduce output - thus >>>>>> de-throttle until revs support full open] >>>>> >>>>> >>>>> The functionality is even easier than that -- open the throttle plate >>>>> when >>>>> the gas pedal is pressed and close the throttle plate when the gas pedal >>>>> is >>>>> released. You can get bogged down in semantics if you want, but the >>>>> functiionality is really that simple Go when the pedal is pressed and >>>>> stop >>>>> going when the pedal is released. At the end of the day, anything else >>>>> is a >>>>> variation on pushing the pedal down or releasing the pedal so that it >>>>> comes >>>>> back up. >>>> >>>> yeah, that meets conditions 3.a& 3.b. oh, wait, no it doesn't. >>>> >>> >>> >>> This is the most important part? >>> >>> It's nonsense! The gas pedal does two things, opens the throttle plate and >>> closes the throttle plate. Period. >>> >>> You should ride the bus. >>> >>> >>> >>> >>> >> >> |