A good digital oscilloscope?
in [Design]
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From: Joel Koltner on 15 Dec 2009 13:52 "Joerg" <invalid(a)invalid.invalid> wrote in message news:7opq9mF3qhhh3U1(a)mid.individual.net... > We still learned how to hobble a stalled car off railroad tracks by using > starter, clutch and first gear. Of course now they have switches on the > clutch that don't let the starter engage unless fully depressed which > defeats that extra safety measure. I would have to guess the the ratio of how often people damaged or ruined their starter or gearbox from trying to start without the clutch all the way in to how often someone ended up with a stalled car on railroad tracks is perhaps about a million to one? :-) > But they all have to keep sloshing around some of the oil around the shaft > lock. There's a reason why even new automatic transmissions run hotter than > gear boxes. And warmer = more losses. Apparently what makes new automatics as efficient or even a little more so than manuals is hitting the optimal shift points better than your average human does. I keep hoping that one of these days an inexpensive and reliable continuously variable transmission finds its way into cars. ---Joel
From: Jim Thompson on 15 Dec 2009 14:02 On Tue, 15 Dec 2009 09:11:42 -0800, John Larkin <jjlarkin(a)highNOTlandTHIStechnologyPART.com> wrote: >On Tue, 15 Dec 2009 08:02:56 -0800, Joerg <invalid(a)invalid.invalid> >wrote: > >>Jim Thompson wrote: >>> On Tue, 15 Dec 2009 07:52:54 -0600, Jim Yanik <jyanik(a)abuse.gov> >>> wrote: >>> >>>> "Joel Koltner" <zapwireDASHgroups(a)yahoo.com> wrote in >>>> news:H3DVm.414201$ua.294023(a)en-nntp-05.dc1.easynews.com: >>>> >>>> >>>>> Hey, don't cars with automatics generally get a mile or two per gallon >>>>> better mileage than manuals? ;-) >>>>> >>>>> ---Joel >>>>> >>>>> >>>> Manuals usually get better mileage,but that is changing in -some- >>>> models,because of the addition of lockup torque converters and CVTs. >>>> >>>> automatics eliminate the need for driver competence. >>>> >>>> Note that "unintended accelleration" crashes occur only with automatics. >>> >> >>They should start teaching the basics again in drivers ed. Like how a >>car works. In Germany you used to not be able to get a license unless >>you could explain how an engine worked, and how other stuff such as >>clutch, gear box or differential worked. >> >>We still learned how to hobble a stalled car off railroad tracks by >>using starter, clutch and first gear. Of course now they have switches >>on the clutch that don't let the starter engage unless fully depressed >>which defeats that extra safety measure. >> >> >>> You're living in the past... I can't recall any car using a purely >>> "slush" type torque converter for at least 30 years, maybe longer. >>> >> >>But they all have to keep sloshing around some of the oil around the >>shaft lock. There's a reason why even new automatic transmissions run >>hotter than gear boxes. And warmer = more losses. > >My Audi is weird: it's a 6-speed automatic, but it has no torque >converter. It has two gear trains, one for odd gears and one for even, >and each train has its own automated clutch. > >Something like this: > >http://www.blogcdn.com/green.autoblog.com/media/2007/09/dsg_audi.jpg > >http://images.google.com/imgres?imgurl=http://www.my-gti.com/wp-content/uploads/dsg_trans_7_speed__550nm_1.jpg&imgrefurl=http://www.my-gti.com/887/volkswagen-dsg-7-speed-dual-clutch-gearbox-high-output&usg=__HFLOWMT2oKZ_i_DYIYjnc-zry5g=&h=905&w=1280&sz=221&hl=en&start=137&sig2=GfNeSyQkB6wul0biVhiuJQ&um=1&tbnid=1b9WYcJGttn2QM:&tbnh=106&tbnw=150&prev=/images%3Fq%3Daudi%2Bdrive%2Btrain%2Bdual%2Bclutch%26ndsp%3D20%26hl%3Den%26sa%3DN%26start%3D120%26um%3D1&ei=esMnS9OnHYmssQPA6fG1DA > > >John The Ford Model-T tranny design is the forerunner for most all automatic transmission schemes... Henry was WAY ahead of his time... he didn't even need a slush pump... he understood planetary gears ;-) ...Jim Thompson -- | James E.Thompson, CTO | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona 85048 Skype: Contacts Only | | | Voice:(480)460-2350 Fax: Available upon request | Brass Rat | | E-mail Icon at http://www.analog-innovations.com | 1962 | Help save the environment! Please dispose of socialism properly!
From: Joerg on 15 Dec 2009 14:07 Joel Koltner wrote: > "Joerg" <invalid(a)invalid.invalid> wrote in message > news:7opq9mF3qhhh3U1(a)mid.individual.net... >> We still learned how to hobble a stalled car off railroad tracks by >> using starter, clutch and first gear. Of course now they have switches >> on the clutch that don't let the starter engage unless fully depressed >> which defeats that extra safety measure. > > I would have to guess the the ratio of how often people damaged or > ruined their starter or gearbox from trying to start without the clutch > all the way in to how often someone ended up with a stalled car on > railroad tracks is perhaps about a million to one? :-) > AFAIK you can't easily ruin the gear box even with the clutch released and in gear. The starter, yes, but even that will take a while if it's a good quality one. >> But they all have to keep sloshing around some of the oil around the >> shaft lock. There's a reason why even new automatic transmissions run >> hotter than gear boxes. And warmer = more losses. > > Apparently what makes new automatics as efficient or even a little more > so than manuals is hitting the optimal shift points better than your > average human does. > Not sure, since the automatic can't see a slope or a curve coming up. Maybe some day it can and it's all GPS-linked. And then the computer goes on the fritz ;-) > I keep hoping that one of these days an inexpensive and reliable > continuously variable transmission finds its way into cars. > Would be nice but I am quite happy with the manual transmission in my car. Does the job and contains no electronics that could fry. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: Rich Grise on 15 Dec 2009 14:23 On Tue, 15 Dec 2009 10:52:38 -0800, Joel Koltner wrote: > "Joerg" <invalid(a)invalid.invalid> wrote in message > news:7opq9mF3qhhh3U1(a)mid.individual.net... >> We still learned how to hobble a stalled car off railroad tracks by using >> starter, clutch and first gear. Of course now they have switches on the >> clutch that don't let the starter engage unless fully depressed which >> defeats that extra safety measure. > > I would have to guess the the ratio of how often people damaged or ruined > their starter or gearbox from trying to start without the clutch all the way > in to how often someone ended up with a stalled car on railroad tracks is > perhaps about a million to one? :-) Well, many years ago I had a 1972 or so Ford Econoline 100 van, and the clutch linkage failed while I was on the road. There was no connection at all from the pedal to the clutch itself. I drove it that way for the rest of the day. Find the right RPM so there's no force on the gears, drop it into neutral, coast to a stop. Turn off the motor, put it in first, and crank the motor 'til it kicks in, and you're driving. Then shifting without a clutch wasn't bad; just feather the throttle to get the RPM at a coast, drop it into neutral, and idle down to the right RPM for the next gear, and drop it into the next gear. I took out the broken piece of linkage at home, and carried it in to work - luckily, I had a "spare" car (a $50.00 winter beater) to get to work in, and I gas-brazed the piece of linkage back together - it was shaped like a tall integral: _ | | | | | | | | _| and one of the elbows had opened up. Slapped it back in when I got home, and the van was none the worse for wear. :-) I got laid in that car[1] probably more than most men deserve. ;-P Cheers! Rich [1] It was a van, but I called it my "tall car". ;-) No rear windows, but it had been tricked out with carpeting and sort of a restaurant-booth arrangement that folded down into a bed. I miss that van. I had vanity plates: "RITCH". ;-)
From: Joel Koltner on 15 Dec 2009 14:25
"Joerg" <invalid(a)invalid.invalid> wrote in message news:7oq5d3F3rbu8hU3(a)mid.individual.net... >So, got a link? The Toyota Corolla gets 26/35MPG (city/highway) with a manual and 27/35 with an automatic. The Nissan Sentra is more impressive at 24/31 (manual) and 25/33 (auto CVT). From here: http://cars.about.com/od/helpforcarbuyers/tp/top10_fuel.htm. In most cases the manuals do slightly better, but clearly there are a few automatics out there that do as well or a tiny bit better than manuals. I have nothing against manuals and arguably then can be a little more fun to drive, but it seems like the fuel economy difference is largely a wash these days... and it's certainly a lot easier to find automatics if you're looking for used cars. |