electronic throttle
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From: Steve Austin on 11 Mar 2010 18:17 clare(a)snyder.on.ca wrote: > On Thu, 11 Mar 2010 13:22:06 -0600, Bob Cooper <bc(a)nowhere.com> wrote: > >> In article <rsmgp5t82blf3lo6kpgno8o267227cdhtg(a)4ax.com>, >> clare(a)snyder.on.ca says... >>> EVERYONE is using drive by wire, or has plans to. It has MANY >>> advantages - and is no more prone, by design, to failure than a cable. >> Sure. That's why all those cables in past cars went haywire and opened >> up throttles. Preaching to the choir, you are. >> You recall all the incidents of million-car recalls because of that, >> right? >> >>> A very simple electrical fault can totally screw up a mechanical cable >>> connection too. A bad ground can allow fault current to flow through >>> the throttle cable, melting the plastic sheath, causing a sticking >>> throttle. It has happened. I've seen it. >>> >> Sure. Thousands of time, probably. Millions of cars were recalled for >> that, weren't they? Throttles going wide open all over the place. >> Those were terrible times. >> >>> Mechanical devices are MORE subject to failure than electronics >>> >> Right. That's why multiple transitors, resistors, lines of code, servo >> motors, and yards and yards of wiring are so much more dependable than a >> cable and a return spring attached to the driver's foot via a pedal. >> Just makes sense. > > > You can believe what you like. Properly designed and implemented > electronic controls are more reliable than properly designed and built > mechanical systems. Ther is NO WEAR, and NO MOVING PARTS. Moving parts > either wear or seize or break in time. > If electronic devices are operated within their design voltage and > temperature parameters they can last virtually forever. 10s of > thousands of operating hours at the minimum. I've replaced more TAC throttle bodies in the last year than throttle cables in my lifetime.
From: Bill Putney on 11 Mar 2010 18:35 clare(a)snyder.on.ca wrote: > ...Properly designed and implemented > electronic controls are more reliable than properly designed and built > mechanical systems. Ther is NO WEAR, and NO MOVING PARTS. Moving parts > either wear or seize or break in time. > If electronic devices are operated within their design voltage and > temperature parameters they can last virtually forever. 10s of > thousands of operating hours at the minimum. You forget one thing: Modern (automotive) electronics are made using surface mount components, and surface mount solder bonds (as currently done in the modern automotive world) are particularly bad at withstanding years of thermal cycling and other environmental exposure. All these electronic module failures (hard and intermittent) are probably 90+% due to the failure of surface mount component-to-board bonds. A chain is only as strong as its weakest link - and that is it. You might argue "Well, then they aren't properly designed and implemented, are they?". That may be true, but it is a fact that you can't get away from in the present state of automotive electronic manufacturing. I claim that the admission has to be one of two things: (1) Surface mount electronics as currently utilized in the present automotive industry do not fit into the category of "proper design and implementation", or (2) Even properly designed and implemented electronics (by modern standards of the automotive industry) are prone to failure. Perhaps you would choose (1)? Or do you not accept that electronic modules in our automobiles have real failure rates over the life of the vehicle? You might have one valid counter to this if you were to say that a proper design would be fail safe (for the uninitiated, that means that things may fail, but when they do, they do so in a safe manner). But then, can we anticipate all failure modes and analyze their results? (I have served on FMEA teams for major manufacturers, so I know what I'm talking about in this area.) It probably is a circular argument, because you could always claim that "...then it is not properly designed and implemented, is it?", and I couldn't disagree with you. Perhaps this relates back to some of the Toyota problems, perhaps not. But electronics do fail - you have to decide if that is due to (1) or (2) above. -- Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')
From: Rodan on 11 Mar 2010 18:37 Rodan wrote: (adding an accelerator pedal position sensor) costs more, it's more complex, it adds more electromechanical hardware and increases electrical, mechanical, and computer interfaces. It introduces multiple new failure modes, while yielding no significant improvement in gas mileage or pollution control. It is a money pit, a maintenance nightmare and a death trap waiting for a victim. ____________________________________________________________________ clare(a)snyder.on.ca wrote: You need to understand emission controls and engine control which you obviously don't, in order to understand HOW ECT makes it better. ___________________________________________________________________ I thought that might be the answer. In the absence of any numbers to show that the gadget-laden accelerator sensor nightmare adds any gas mileage whatsoever or reduces any pollution whatsoever, the response is essentially, "You're too dumb to understand." You've got me there. Henceforth, I'll treat it as a religious question for which the answer is too complex for a mere mortal, to be entrusted only to qualified gurus. Best regards to all RAGers. Rodan.
From: Bill Putney on 11 Mar 2010 18:39 Steve Austin wrote: > clare(a)snyder.on.ca wrote: >> You can believe what you like. Properly designed and implemented >> electronic controls are more reliable than properly designed and built >> mechanical systems. Ther is NO WEAR, and NO MOVING PARTS. Moving parts >> either wear or seize or break in time. >> If electronic devices are operated within their design voltage and >> temperature parameters they can last virtually forever. 10s of >> thousands of operating hours at the minimum. > > I've replaced more TAC throttle bodies in the last year than throttle > cables in my lifetime. 'ere ya go. (But as I just posted, the claim could be "Well, then the design was not properly designed and implemented, was it?", and eventually it becomes a semantical argument that would continue in circles ad infinitum - not that that would ever happen on a newsgroup. LOL!) -- Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')
From: clare on 11 Mar 2010 20:03
On Thu, 11 Mar 2010 16:04:31 -0500, clare(a)snyder.on.ca wrote: >On Wed, 10 Mar 2010 20:28:26 -0800, jim beam <me(a)privacy.net> wrote: > >>On 03/09/2010 10:15 PM, Rodan wrote: >>> clare(a)snyder.on.ca wrote: >>> >>> Toyota throttle has 2 hall effect sensors. The output of one tracks the >>> other but is offset. In other words, one starts at say, 0 volts, and the >>> other at, say 1 volt - and they increase in step with each other. >> >>how can that be true??? >> >>http://en.wikipedia.org/wiki/Hall_effect >> >>hall effect sensors are used for gross position detection, not small >>scale linear deflections. they can be used for "wot" detection, but >>their ability to work over a wide positioning range is limited. that's >>why they're used in timing for things like crank position [rotational] >>sensors where you're counting pulse rates, not graduation functions. >> > >You are wrong. Hall effect sensors are used instead of potentiometers >in all kinds of "variable output" controls including the throttles on >virtually all the electric scooters and e-bikes you see out there. > >They are called "Ratiometric Linear Hall Effect Sensors. > More research brings MORE interesting information. A "hall effect switch" is an adaptation of the basic "hall effect sensor", where a schmitt trigger and a comparator use the hall voltage to produce a "digital" signal. The basis of a hall effect sensor (the hall effect) is when current flows through a conductor in the presence of a magnetic field a voltage is produced at right angles to the current flow, and it varies with magnetic flux in both level and polarity. |