From: atec "atec77 on 9 Feb 2007 05:30
Andrew McKenna wrote:
> jlittler(a)my-deja.com wrote:
> <--- snipperage --->
>> And your statement is indeed correct - there's a difference between
>> the mechanical input and the mechanical load. Pure semantics of
>> course. mechanical load (as torque) plus electrical load(as torque)
>> equals mechanical input required(as torque). The mechanical load is a
>> constant (ceteris paribus), the electrical load changes with, well,
>> the electrical load <grin> (1). To be more accurate the torque/turning
>> force that you have to provide to generate a current equal to the
>> current being drawn is increased as the current required increases(2)
>> (1) there obviously being more than one meaning of the word load in
>> this context - one being current drawn, the other being turning force
>> (2) still not sure I'm explaining that particularly well
> I wasn't going to shove my oar in again but that's such a good
> translation I can't resist it. Of course you have to spin the
> electricity generating thing faster if you want more electricity,
> nobody's arguing that you don't. What I was saying was that the
> increased electrical load does not cause engine RPM to drop, because it
> Simple test: drive a test vehicle (use Nev's) to a stadium with lights
> and connect lights to a light circuit on the test vehicle (don't ask me
> how, there seem to be a gadmillion electrical geniuses in here, you lot
> figure it out). Step 2: turn on lights. If I'm wrong the test vehicle
> will stall. If I'm right the lights won't come on but the test vehicle
> will run normally.
In fact if you take an ungoverned motor driving a genny it will in that
circumstance slow in revs due to load increase which is why a governing
unit is used to maintain speed , now do you agree ?
From: Knobdoodle on 9 Feb 2007 06:08
"Tim Moran" <tim-usenet(a)evilbastard.org> wrote in message
> In article <1170907020.634294.244700(a)v45g2000cwv.googlegroups.com>,
> jlittler(a)my-deja.com says...
>> On Feb 7, 5:30 pm, Toosmoky <toosm...(a)hotmail.com> wrote:
>> > Nev.. wrote:
>> > > Toosmoky wrote:
>> > There was a lot to take
>> > in and I must admit I was somewhat amazed at the thinking that's gone
>> > into them. A lot of current cars have such features. One that I forgot
>> > about is an automatic fuel cutoff.
>> Christ I had a 1979 Jaguar that had an auto fuel cutoff(1)
> I read that as Christ had a 1979 Jaguar
> I'm guessing crucifixion didn't seem so bad after that
One of the less talked-about "passions"........
From: Knobdoodle on 9 Feb 2007 06:15
"Theo Bekkers" <tbekkers(a)bekkers.com.au> wrote in message
> Knobdoodle wrote:
>> "Andrew McKenna" wrote:
>>> No, you need to push harder to get the result if you add electrical
>>> load. It cannot possibly get harder to spin.
>> I bet if you said this 100 times it would still be just as hilariously
>> What on earth are you actually trying to say?
> I think he's saying that if you turn an alternator with no load and with
> full load, no extra power input is required. That must be why our back-up
> gen-set gets louder when we put the air-con load on it. 3.9 litre John
> Deere with a 3 phase 44kw alternator.
> Anybody want to tell me it doesn't use more fuel when we load it up to 40
> Try holding one of these permanent magnet alternators in your hand and
> spin the rotor with your other hand. Easy isn't it? Now twist the output
> wires together and give it another spin. That would be max load. What do
> you mean it stops dead? It surely doesn't require more turning force?
> Simple brakes for an induction motor is to short the terminals together.
> This is wired into a lot of machinery. Stops very quickly. An induction
> motor is the same design as your perm magnet alternator.
Now that you mention it; I think I read that the Qld electric and
diesel-electric trains use this system for brakes.
The added advantage is that without turning there's no back-EMF so they're
From: Knobdoodle on 9 Feb 2007 06:17
"MrMoped" <MrMoped49(a)hotmail.com> wrote in message
> "Knobdoodle" <knobdoodle(a)hotmail.com> wrote in message
>> "MrMoped" <MrMoped49(a)hotmail.com> wrote:
>>> Simple physics really! When switched on, the headlamp assembly pushes
>>> the light beams forward (this is particularly noticable in the absence
>>> of daylight), this is called an action. So using Newtons third law which
>>> states that for every action there must be an equal and opposite
>>> reaction, the same force applied by the headlamp to push the light beams
>>> is then also applied to the vehicle, pushing it back! Extra petrol is
>>> used to overcome the force applied by the headlamps.
>> But you've got red ones pushing you from behind and EVERYONE knows red
>> ones are faster!
> True, as a general rule the red ones are faster and this has been a
> concern to (most) motorcycle manufacturers worldwide.
> Having a fast red light at the rear of the motorcycle was a huge concern
> in the early days of motorcycling as it was soon realised that having a
> fast light (red) at the rear and a not-so-fast light at the front led to
> the rear of the motorcycle trying to overtake the front at every
> opportuity - this was deemed to be "not rider friendly".
> To counteract the power of the red light, a very mild or low wattage light
> was fitted to the rear whilst a stronger/higher wattage light was fitted
> to the front. This has worked very well.
> The ratio between front and rear light is very sensitive. A typical setup
> of 60/55 watt high/low beam front light to 5 watt tail light works well in
> most situations but the addition of a 20 watt brake light has added an
> element of danger by making the motorcycle unstable. If you require proof
> of tis, try the following:
> - ride along (at any speed) with the mind in neutral and then apply the
> front brake as hard as you possibly can and do not ease off under any
> circumstances. The rear of the motorcycle will rise and continue rising
> until the red, rear light has overtaken the front. Some will try and
> attribute this phenomenon to the action of the brakes but that is not 100%
> correct. Squeezing the front brake as hard as you can imparts maximum
> energy to the faster red light. A similar effect can be achieved by
> applying maximum force to the rear brake.
> So yes the red lights are the fastest but they can be tamed with some
> (un)sound engineering practices so as not to detract from the motorcycling
My old mach111 certainly used to conform to this principle!
From: Knobdoodle on 9 Feb 2007 06:27
"Hammo" <hbaj2006(a)aapt.net.au> wrote in message
> On 9/2/07 12:34 AM, in article
> YFFyh.4682$sd2.653(a)news-server.bigpond.net.au, "Knobdoodle"
> <knobdoodle(a)hotmail.com> wrote:
>> "Nev.." <idiot(a)mindless.com> wrote:
>>> I think you've been reading too many physics books and you've lost sight
>>> of reality. Are you saying that if I measure something once per second
>>> and then multiply that by 3600 my result is not an accurate measure of
>>> hourly rate? Do you think the computer controlling the fuel rate just
>> No; it actuates the injector the exact amount that it's been told to for
>> conditions it's measured.
>> It then displays the exact mpg (L/Hr, Km per kilojoule or whatever)
>> it's been told to display too.
>> But it doesn't have any idea what a litre actually is and it certainly
>> doean't have any ability to actually measure one!
> It's measured, but it can't measure?