The Electric Car
in [Design]
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From: Jim Thompson on 31 Jul 2007 21:06 On Tue, 31 Jul 2007 17:02:40 -0700, Charlie Edmondson <edmondson(a)ieee.org> wrote: >Eeyore wrote: > >> >> MooseFET wrote: >> >> >>>Guy Macon <http://www.guymacon.com/> wrote: >>> >>>>Martin Griffith wrote: >>>> >>>>>If they could recharge in 10 mins, the US power grid would burn out >>>> >>>>To a first aproximation, given a large number of electric cars >>>>on a power grid, the load on the power grid is almost the same >>>>whether they recharge in ten minutes or ten hours. In the >>>>later case, you have 60 times as many cars being recharged at >>>>any given time, each of which is drawing 1/60th as much power. >>>> >>>>Short recharge times would, however, have a large effect on the >>>>time of day that the charging would take place. At ten hours >>>>everyone will plug in when they get home. At ten minutes a >>>>large number will try to recharge in the morning right before >>>>leaving for work. And the grid has to be sized for peak load, >>>>not average load... >>> >>>At 2 seconds, people will recharge it just before they set out. At >>>ten minutes, they will plug the charger in when they get how. Nobody >>>wants to wait an extra ten minutes before they start on their hour >>>long commute. >>> >>> >>>>Either way, I don't see the total capacity of the current power >>>>grid being enough. Household nuclear reactors, anyone? :) >>> >>>The owners will get a better deal on the power if they let the power >>>company control the charging current. The feature will be built into >>>the charger and most people will use it. >> >> >> That's a very sensible idea actually. The recharging rate could be dynamically >> modulated to provide a full charge quite quickly whilst at the same time >> minimising peak load on the grid (and obtaining optimal use of spare capacity) . >> That'll keep the power generators very happy indeed. >> >> Plus, you're presumably get a discount for plugging it in earlier rather than >> later. That might provide the required incentive to do that. >> >> I'd patent it FAST. >> >> Graham >> >> >Also, it isn't like 10 million cars will suddenly appear overnight, they >would be added over a period of many years. During this transition, >power companies will slowly be building up the grid, esp. in areas that >have more electric vehicles... > >Charlie Just think of the litter, cars with dead batteries stalled on the freeway, and no where to plug them in ;-) ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | America: Land of the Free, Because of the Brave
From: MooseFET on 31 Jul 2007 21:07 On Jul 31, 7:21 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: > On Mon, 30 Jul 2007 20:02:28 -0700, Richard Henry > > > > <pomer...(a)hotmail.com> wrote: > >On Jul 30, 7:20 pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- > >Web-Site.com> wrote: > >> On Mon, 30 Jul 2007 19:12:03 -0700, Richard Henry > > >> <pomer...(a)hotmail.com> wrote: > >> >On Jul 30, 5:48 pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- > >> >Web-Site.com> wrote: > >> >> On Mon, 30 Jul 2007 17:30:01 -0700, "J.A. Legris" > > >> >> >- I said fuel consumption will never decrease much unless cars are > >> >> >much lighter, but even radically lighter vehicles are no long-term > >> >> >solution on this overpopulated planet > > >> >> Amen! I keep telling people that, and they look at me like I'm some > >> >> kind of idiot. > > >> >You have also told us how you like to drive your big import illegally > >> >fast and tried to rationalize it by claiming that among the vehicle's > >> >luxury features is that it runs more efficiently at high speed. > > >> I didn't rationalize anything. However I do agree that leftist > >> weenies should be taxed more heavily to support my excesses ;-) > > >> And I certainly have no problem with YOU driving a tin can, just NOT > >> my children and grandchildren ;-) > > >OOHH!. Think of the children... > > >You sound like a leftist weenie. > > >Please explain again the more-efficient-at-higher-speed feature. > > I don't ever recall saying "more-efficient-at-higher-speed". > > But I guess it WOULD depend on your definition. The engine is > optimized right around 3000RPM (85MPH), but external drag is higher. If you shift to a lower gear, 3000 RPM is at a lower speed. If there isn't an issue that is well modeled by a fuel leak, the milage would improve. > > ...Jim Thompson > -- > | James E.Thompson, P.E. | mens | > | Analog Innovations, Inc. | et | > | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | > | Phoenix, Arizona Voice:(480)460-2350 | | > | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | > | http://www.analog-innovations.com | 1962 | > > America: Land of the Free, Because of the Brave
From: MooseFET on 31 Jul 2007 21:08 On Jul 31, 8:19 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- Web-Site.com> wrote: > On Tue, 31 Jul 2007 08:14:21 -0700, John Larkin > > > > <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: > >On Tue, 31 Jul 2007 14:37:31 +0000, Guy Macon > ><http://www.guymacon.com/> wrote: > > >>Jim Thompson wrote: > > >>>I don't ever recall saying "more-efficient-at-higher-speed". > > >>>But I guess it WOULD depend on your definition. The engine is > >>>optimized right around 3000RPM (85MPH), but external drag is higher. > > >>Assuming that "optimized" means maximum efficiency as opposed > >>to maximum power or torque, wouldn't it be more efficient at > >>3000 RPM in first gear? > > >>Part of me thinks about the far lower drag and says that it > >>would. Part of me thinks about those pistons moving up and > >>down more times per mile and sucking in about the same amount > >>of fuel per cycle and says that it wouldn't. Maybe it needs > >>an engine sized for 3000 RPM in first gear to make it work? > > >>Also, I can't prove it, but I suspect that hard accelerating > >>to some speed (don't know how fast) and then shutting down > >>the engine and coasting down, then repeating, gives the > >>maximum fuel economy. > > >Interesting curve: > > >http://www.fueleconomy.gov/feg/driveHabits.shtml > > >And it is reasonable to also factor in the value of your time. > > >John > > "Remove excess weight"... don't give a leftist weenie a ride ;-) At those speeds it is drag not weight that matters. You shouldn't wear a dress while driving.
From: krw on 1 Aug 2007 00:12 In article <1185930451.854228.138310(a)x35g2000prf.googlegroups.com>, kensmith(a)rahul.net says... > On Jul 31, 7:21 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- > Web-Site.com> wrote: > > On Mon, 30 Jul 2007 20:02:28 -0700, Richard Henry > > > > > > > > <pomer...(a)hotmail.com> wrote: > > >On Jul 30, 7:20 pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- > > >Web-Site.com> wrote: > > >> On Mon, 30 Jul 2007 19:12:03 -0700, Richard Henry > > > > >> <pomer...(a)hotmail.com> wrote: > > >> >On Jul 30, 5:48 pm, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- > > >> >Web-Site.com> wrote: > > >> >> On Mon, 30 Jul 2007 17:30:01 -0700, "J.A. Legris" > > > > >> >> >- I said fuel consumption will never decrease much unless cars are > > >> >> >much lighter, but even radically lighter vehicles are no long-term > > >> >> >solution on this overpopulated planet > > > > >> >> Amen! I keep telling people that, and they look at me like I'm some > > >> >> kind of idiot. > > > > >> >You have also told us how you like to drive your big import illegally > > >> >fast and tried to rationalize it by claiming that among the vehicle's > > >> >luxury features is that it runs more efficiently at high speed. > > > > >> I didn't rationalize anything. However I do agree that leftist > > >> weenies should be taxed more heavily to support my excesses ;-) > > > > >> And I certainly have no problem with YOU driving a tin can, just NOT > > >> my children and grandchildren ;-) > > > > >OOHH!. Think of the children... > > > > >You sound like a leftist weenie. > > > > >Please explain again the more-efficient-at-higher-speed feature. > > > > I don't ever recall saying "more-efficient-at-higher-speed". > > > > But I guess it WOULD depend on your definition. The engine is > > optimized right around 3000RPM (85MPH), but external drag is higher. > > > If you shift to a lower gear, 3000 RPM is at a lower speed. If there > isn't an issue that is well modeled by a fuel leak, the milage would > improve. Ever consider that transmissions aren't equally efficient in all gears and perhaps the over-drive locked-up may be a tad more efficient than the lower gears? There is also work done just spinning the engine. Me thinks you're wrong. -- Keith
From: John Larkin on 1 Aug 2007 00:29
On Tue, 31 Jul 2007 18:08:26 -0700, MooseFET <kensmith(a)rahul.net> wrote: >On Jul 31, 8:19 am, Jim Thompson <To-Email-Use-The-Envelope-I...(a)My- >Web-Site.com> wrote: >> On Tue, 31 Jul 2007 08:14:21 -0700, John Larkin >> >> >> >> <jjlar...(a)highNOTlandTHIStechnologyPART.com> wrote: >> >On Tue, 31 Jul 2007 14:37:31 +0000, Guy Macon >> ><http://www.guymacon.com/> wrote: >> >> >>Jim Thompson wrote: >> >> >>>I don't ever recall saying "more-efficient-at-higher-speed". >> >> >>>But I guess it WOULD depend on your definition. The engine is >> >>>optimized right around 3000RPM (85MPH), but external drag is higher. >> >> >>Assuming that "optimized" means maximum efficiency as opposed >> >>to maximum power or torque, wouldn't it be more efficient at >> >>3000 RPM in first gear? >> >> >>Part of me thinks about the far lower drag and says that it >> >>would. Part of me thinks about those pistons moving up and >> >>down more times per mile and sucking in about the same amount >> >>of fuel per cycle and says that it wouldn't. Maybe it needs >> >>an engine sized for 3000 RPM in first gear to make it work? >> >> >>Also, I can't prove it, but I suspect that hard accelerating >> >>to some speed (don't know how fast) and then shutting down >> >>the engine and coasting down, then repeating, gives the >> >>maximum fuel economy. >> >> >Interesting curve: >> >> >http://www.fueleconomy.gov/feg/driveHabits.shtml >> >> >And it is reasonable to also factor in the value of your time. >> >> >John >> >> "Remove excess weight"... don't give a leftist weenie a ride ;-) > >At those speeds it is drag not weight that matters. You shouldn't >wear a dress while driving. You get the best mileage if you wear nothing at all. John |