EV Digest 2674
Topics covered in this issue include:
1) Re: ev
by "1sclunn" <[EMAIL PROTECTED]>
2) Re: Better range from less weight
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Better range from less weight
by John Lussmyer <[EMAIL PROTECTED]>
4) Interesting possible 3 wheeler donor kit
by John Lussmyer <[EMAIL PROTECTED]>
5) Re: Sob... I think if fried my motor.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
6) Re: Tom and Ray on Hydrogen cars.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
7) Re: AC controllers
by "Mark Thomasson" <[EMAIL PROTECTED]>
8) Re: Tom and Ray on Hydrogen cars.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
9) Re: AC controllers
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
10) RE: Interesting possible 3 wheeler donor kit
by "Chris Tromley" <[EMAIL PROTECTED]>
11) Re: I need to start stopping
by [EMAIL PROTECTED]
12) Re: Interesting possible 3 wheeler donor kit
by Peter VanDerWal <[EMAIL PROTECTED]>
13) Re: Don't tap the battery pack (was: Today's mystery question withelectricity)
by "Seth Dallob" <[EMAIL PROTECTED]>
14) Re: AC controllers
by Peter VanDerWal <[EMAIL PROTECTED]>
15) Re: AC controllers
by "Mark Thomasson" <[EMAIL PROTECTED]>
16) Re: AC controllers
by "Mark Thomasson" <[EMAIL PROTECTED]>
17) Re: AC controllers
by "Mark Thomasson" <[EMAIL PROTECTED]>
18) EV Digest Mode
by "Thomas Shay" <[EMAIL PROTECTED]>
19) Re: EV Digest Mode
by Mike Burgess <[EMAIL PROTECTED]>
20) Re: EV Digest Mode
by John Lussmyer <[EMAIL PROTECTED]>
--- Begin Message ---
----- Original Message -----
From: "garry" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, March 23, 2003 9:09 PM
Subject: ev
> Hi people,
>
> I'm on a bit of a buzz today and I just thought I would share it with you.
****
There's that problem with words again ;-)/******
> This will seem unimportant to some but for someone who has never played
golf
> ones first ride in a golf cart can be quite exciting, especially if you
are
> somewhat keen on building an EV.
Everboday loves to ride in electric golf carts
> I went out to look at a cart that is for sale locally, I figure its
already
> an EV so maybe it would make my simple project easier.
Your project is a fork lift motor in a car 8-)/
> The cart I was to look at was stored behind 3 other carts and someone had
to
> move them to get it out and take it for a test ride :)
>
> I think I have enough ev bits now to make one but its almost irresistible
to
> grab this and add it to the pile, a nice 300 amp controller 6 Trojan
t105's
> a fuel gauge and charger and it doesn't need building you just jump on and
> take it for a joy ride :)
put some big tires on it and it will be move on down the road.
I'll bet there's not one street EV for miles of where you are so lets get
going with the car project . Are you ready for all the people that will be
croweding around you and your EV , asking questions ect. 5 years form now
when your showing off your latest EV at a EV rally your putting on . with a
9 adc motor , zilla controller, and pfc charger (with the program now)
sombody will ask you these fames words. " couldn't ya put a generator on the
wheel and charge those batteries while driving?"
do be putting motor on tranny soon .....while eating lots of cookes
> Shame they wont let us use them on the roads here ... I have a will so
there
> is bound to be a way :)
>
> I'm hooked :)
>
It's illegal here to .
> Garry Stanley
>
> Cable.net.nz
>
>
--- End Message ---
--- Begin Message ---
Jim Coate wrote:
>
> Lee Hart wrote:
> > Around here, a popular high school stunt is to take the body off some
> > old rused out pickup truck, and crudely graft on some car body that has
> > about the right wheelbase. The car body normally sits absurdly high on
> > the frame, but this allows them to use ridiculously oversized tires.
>
> This just begs for a picture to explain what the cars look like in the
> end... is there a slang name for what they call these creations? (so I
> can Google my way to a kid who put his creation on a web page)
There's bound to be a name for them, but I don't know what it is. This
is a small town, and there are at least 2-3 of them around. Anyone else
know?
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
At 11:23 AM 3/24/2003 -0800, Lee Hart stated:
There's bound to be a name for them, but I don't know what it is. This
is a small town, and there are at least 2-3 of them around. Anyone else
know?
Not a clue, the ones I've usually seen were Camaro bodies on a 4x4 truck
chassis.
REALLY stupid looking.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.Com
--- End Message ---
--- Begin Message ---
A friend just sent this to me: http://www.indycycleonline.com/index.htm
It's a 3 wheeler using a motorcycle as the power plant. The company is
planning on selling kits.
Wonder what kind of EV you could build from something like this? :-)
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.Com
--- End Message ---
--- Begin Message ---
Don't blow that controller. Sell it to me and get your zilla..uuhhhh what
kind of controller are you running?? Lawrence Rhodes.......
----- Original Message -----
From: "1sclunn" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 3:04 AM
Subject: Re: Sob... I think if fried my motor.
>
>
> >
> > Lawrence Rhodes wrote:
> > > By revving the motor and popping the clutch I probably caused a a big
> spike
> > > and fried the controller
>
> slipping not popping :-) That is a nice EV , dosn't look like room for
big
> ass controller although the new Zilla is small. Who will be first . Man
do
> i want one . I am pine ing for two 9" and a big one , Just so I can get to
> work on time. wish my old controller would blow.
>
--- End Message ---
--- Begin Message ---
At this moment I am forwarding this to the Tappet Bros. Lawrence
Rhodes.......
----- Original Message -----
From: "Chris Tromley" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 4:44 AM
Subject: RE: Tom and Ray on Hydrogen cars.
> Lawrence Rhodes posted:
>
> An astoundingly clear-headed synopsis of the government-endorsed push
> toward fuel cell vehicles, considering the "Tappet Bros." are deeply
> entrenched in the ICE world:
>
> > Dear Tom and Ray:
> >
> > President Bush talked about a "hydrogen car" in his State of
> > the Union address. Is this a realistic possibility during the
> > Bush administration? -- Jim
> >
> > Ray: Maybe during the Jenna Bush administration, Jim. The
> > technology itself works, but people "in the know" say it's
> > going to be at least 20 years before hydrogen-powered cars
> > are viable on a large scale -- if then.
> >
> > Tom: The main problems are: (1) the fuel cell "stacks" are
> > still incredibly expensive to build, (2) the range of the
> > cars is insufficient and (3) there's no national
> > infrastructure (like gas stations) to support hydrogen. So
> > it's not going to happen anytime soon.
> >
> > Ray: So, why is the president talking about hydrogen-powered
> > cars? Well, in my humble opinion, he's creating a distraction.
> >
> > Tom: I think so, too. You probably know that we now import
> > boatloads of foreign oil every day. And almost everybody
> > agrees that this is not a good thing (except for the
> > countries that sell us the oil). So what do you do about it?
> >
> > Ray: Well, you can try to find more oil here at home, by
> > drilling in Alaska's forests, for instance. Or you can force
> > people to use less oil. The president knows that both of
> > these options are pretty unpopular. So he's doing what any
> > good politician would do: He's changing the subject.
> >
> > Tom: Here's another reason why he might want to distract us
> > from thoughts of fuel economy and foreign oil. With no
> > pressure on American car companies to increase gas mileage,
> > the Japanese have taken a significant lead in the most
> > important new propulsion technology in decades: hybrid
> > engines. Hybrid engines use battery power some of the time
> > and gasoline power at other times, and they never have to be
> > plugged in. They're a great way to increase mileage without
> > sacrificing power or convenience. And you're going to see
> > Americans adopting them in big numbers over the next five to 10 years.
> >
> > Ray: Who makes the best-selling hybrid cars in America? Honda
> > and Toyota. So, instead of urging America to make more
> > fuel-efficient cars and cut down on foreign oil by raising
> > the Corporate Average Fuel Economy standards, or urging U.S.
> > manufacturers to catch up with the Japanese on hybrids --
> > which would make a huge difference right away -- the
> > president's talk about hydrogen cars is, essentially, the old
> > "Hey, everybody, look over there!"
> >
> >
> > � 2003 by Tom and Ray Magliozzi and Doug Berman Distributed
> > by King Features Syndicate, Inc.
>
> I gotta give these guys credit for open minds and a fully-functioning BS
> detector. I wonder if they might be receptive to challenging the false
> but widely held belief that EVs are impractical? Where are these guys
> located? Is there anyone nearby who could loan them a nice conversion
> EV for a week or so?
>
> Wouldn't it be nice to hear these guys say something like:
>
> ----------
> Tom: Thanks to loyal listener and electric vehicle owner John Q.
> Lotsawatts, my electrically-challenged brother and I got to live with a
> real electric car for a week. Let me tell you something, when those
> automotive journalists tell you the engine in some new car is as smooth
> as an electric motor, they no idea what they're talking about. Man!
> Talk about eerily smooth and silent! This was no sports car, but I was
> surprised by the acceleration too.
>
> Ray: Yeah, and I have to admit I was more worried about the range than I
> should have been. This car is a converted econobox, so it only has 40
> miles of useful range. But you know what? I only drive maybe 20 miles
> a day, and the car starts out fully charged every morning. This would
> make a *great* second car.
> ----------
>
> OK, maybe I'm dreaming. But it couldn't hurt to ask. Anyone know where
> these guys are?
>
> Chris
>
>
--- End Message ---
--- Begin Message ---
See rebuttals below. Thanks for the comments. Mark Thomasson
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: "EV" <[EMAIL PROTECTED]>
Sent: Sunday, March 23, 2003 11:18 PM
Subject: Re: AC controllers
> Been their done that. This idea dates back over 100 years and used to
> be how all EVs operate.
This new method has a distinct difference from the previous method. The
batteries are grouped with one battery in the first bank, two batteries in
the second bank, four batteries in the third bank, etc, doubling as you go
up. The higher you go, the more steps you get. The arrangement is
analogous to a binary counter, where the first place in the one's counter,
the second place is the two's counter, the third place is the four's
counter, etc. By rearranging the batteries in these groups, you get every
step from zero to full voltage, using the minimum number of relays.
> The problem is you end up with discreet voltage steps instead of the
> smooth variability of a modern PWM controller.
Very true, but with enough steps, you don't notice much difference. The
minibike has only three steps from zero to 30 mph, which is a little coarse.
I think seven steps in that speed range will work great.
> Add in the fact that
> high current contactors are very expensive (more expensive for the set
> than a PWM controller) and it's easy to see why almost nobody builds EVs
> that way anymore.
This is a concern that needs more research. But (as you state below) in the
small horse power range, its really cheap. My 50 DC ampere relays were 6
for $30 on Ebay. With a 36 volt system, that's a 1.8 KW capability. The
relays seem to take 100 amperes ok when I'm showing off in front of the
neighbors, but I'm sure that kind of load will eventually wear them out
prematurely.
>
> FWIW they were still using this method in the '70s for golf carts and
> City/Commuta cars.
>
> It works fine on low power setups though.
>
> PS Contactor REGEN only works with PM motors and shunt/sep ex motors.
> Doesn't work worth beans with series wound motors. But then REGEN with
> series wound motors is tough to do any way.
Yes, I'm using a PM motor.
>
> On Sun, 2003-03-23 at 20:57, Mark Thomasson wrote:
> > I invite everyone to comment on the following idea for a low tech method
of
> > controlling motor voltage, and thus vehicle speed. Instead of leaving
the
> > batteries in a monolithic lump and controlling motor voltage with a
> > sophisticated electronic device, lets use the fact that the battery bank
is
> > composed of smaller units that may be rearranged with contactors to get
> > various voltages. For example, with seven batteries in the bank, it is
> > possible to rearrange them to get seven voltage steps, from zero volts
to
> > the voltage of all the batteries in series. With 15 batteries, 15 steps
are
> > possible. The trick is to rearrange the batteries without using an
> > unreasonable number of contactors. See
> > http://www.geocities.com/thomassonmj/electric_drive.html for a diagram
of
> > how this may be done. http://www.austinev.org/evalbum/439.html shows
the
> > test platform. I started small with a minibike and only 3 voltage steps
> > (using three 12 volt batteries) in the control system. The three relays
and
> > a multiposition switch comprising the control system cost less than $20.
> > Electro-mechanical relays are much easier to trouble shoot and repair
that
> > electronic FET's and integrated circuits, and more efficient. Solid
state
> > relays could also be used. Regenerative braking occurs automatically as
you
> > back off the throttle, or not at all if the throttle goes immediately to
> > zero.
> >
> > Criticize freely... I can take it!
> >
> > Thanks for your feedback.
> >
> > Mark Thomasson
> >
> >
> > ----- Original Message -----
> > From: "1sclunn" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Saturday, March 22, 2003 6:59 PM
> > Subject: Re: AC controllers
> >
> >
> > > Hi Mark
> > ...................
> > >
> > > Tell us of your project? what do you want it to do?
> > >
> > ....................
> >
> --
> EVDL
>
--- End Message ---
--- Begin Message ---
Great idea. I hear they work at their shop every day. Lawrence Rhodes.....
----- Original Message -----
From: "Jim Coate" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 5:34 AM
Subject: Re: Tom and Ray on Hydrogen cars.
> Chris Tromley wrote:
> > OK, maybe I'm dreaming. But it couldn't hurt to ask. Anyone
> > know where these guys are?
>
> They are in Cambridge, MA which is near Boston. I once thought it would
> be fun to have them do my annual state inspection (since no emissions,
> basically certifying that the light work), but they don't do
> inspections. I don't have the right vehicle (or Waylamd personality) to
> go get their attention by leaving rubber on their sidewalk... if Jeremy
> is still on the list, maybe his Optima-based fun car could pay a visit?
> Or maybe someone has an EV1 hidden under their mattress that they could
> show off?
>
> _________
> Jim Coate
> 1992 Chevy S10
> 1970's Elec-Trak
> http://www.eeevee.com
>
--- End Message ---
--- Begin Message ---
This would be safe. Lawrence Rhodes.......
IE. a 48V pack of 4 12V batteries will be arranged as all four in
parallel for 12V, two sets of two for 24V and all together for 48V. Plus
usually a starting resistor in series with the 12V setup. This gives
four steps, plus stop.
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: "EV" <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 8:12 AM
Subject: Re: AC controllers
> He was talking about apping the pack at each battery to provide
> different voltages.
> For example with a 36V pack of 12V 60ah(at EV levels) batteries he would
> tap it at 12V, 24V and 36V (he actuallly mentioned many more batteries)
> So low speed woul only use the first battery, not the second and third.
> Medium speed would use the first two batteries but not the last and high
> speed would use all of the batteries.
>
> So when you toddle around at low speed you are only drawing from one
> battery. Lets say you pull 20 ah out. Then he goes up town at medium
> speed using the first two batteries and pulls another 20 ah. The first
> battery is now down 40ah, the second is down 20 ah and the third is
> fully charged.
> He comes back along the freeway using all batteries and draws another 20
> ah. The first battery is down 60ah (it's dead), the second is down 40
> ah, and the third is only down 20ah.
>
> Now even though we have another 20 ah left in the second battery and 40
> ah left in the third we can't use it because the first battery is dead.
>
> In this example we could only access 2/3 of the battery packs capacity
> and most of that was at low speed. The pack is now way out of balance
> and you have to charge the batteries individually.
>
> On Mon, 2003-03-24 at 07:42, Lawrence Rhodes wrote:
> > Hmmm. No, seems that all get used all the time. Unless I am missing
> > something. Lawrence Rhodes.....
> > ----- Original Message -----
> > From: "Peter VanDerWal" <[EMAIL PROTECTED]>
> > To: "EV" <[EMAIL PROTECTED]>
> > Sent: Sunday, March 23, 2003 10:08 PM
> > Subject: Re: AC controllers
> >
> >
> > > Oops, forgot to mention.
> > > Contactor controllers normally rearrange the pack into series/parallel
> > > setups.
> > > IE. a 48V pack of 4 12V batteries will be arranged as all four in
> > > parallel for 12V, two sets of two for 24V and all together for 48V.
Plus
> > > usually a starting resistor in series with the 12V setup. This gives
> > > four steps, plus stop.
> > >
> > > Tapping the pack at individual batteries like you suggest means that
> > > none of the batteries will be discharged to the same level. The first
> > > battery gets used all of the time and the one at the other end of the
> > > string hardly ever gets used.
> > >
> > > This causes the pack to become unbalanced(a bad thing). Your range
will
> > > be limited by the first battery which will run out fairly quickly,
while
> > > 1/2 the batteries are hardly discharged at all.
> > >
> > > Range from this setup will be about 1/4 the range of using all the
> > > batteries as one pack with a PWM controller or a series/parallel
> > > contactor controller.
> > >
> > > > > various voltages. For example, with seven batteries in the bank,
it
> > is
> > > > > possible to rearrange them to get seven voltage steps, from zero
volts
> > to
> > > > > the voltage of all the batteries in series. With 15 batteries, 15
> > steps are
> > > > > possible. The trick is to rearrange the batteries without using
an
> > > > > unreasonable number of contactors. See
> > > > > http://www.geocities.com/thomassonmj/electric_drive.html for a
> > diagram of
> > > > > how this may be done. http://www.austinev.org/evalbum/439.html
shows
> > the
> > > > > test platform. I started small with a minibike and only 3 voltage
> > steps
> > > > > (using three 12 volt batteries) in the control system. The three
> > relays and
> > > > > a multiposition switch comprising the control system cost less
than
> > $20.
> > > > > Electro-mechanical relays are much easier to trouble shoot and
repair
> > that
> > > > > electronic FET's and integrated circuits, and more efficient.
Solid
> > state
> > > > > relays could also be used. Regenerative braking occurs
automatically
> > as you
> > > > > back off the throttle, or not at all if the throttle goes
immediately
> > to
> > > > > zero.
> > > > >
> > > > > Criticize freely... I can take it!
> > > > >
> > > > > Thanks for your feedback.
> > > > >
> > > > > Mark Thomasson
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "1sclunn" <[EMAIL PROTECTED]>
> > > > > To: <[EMAIL PROTECTED]>
> > > > > Sent: Saturday, March 22, 2003 6:59 PM
> > > > > Subject: Re: AC controllers
> > > > >
> > > > >
> > > > > > Hi Mark
> > > > > ...................
> > > > > >
> > > > > > Tell us of your project? what do you want it to do?
> > > > > >
> > > > > ....................
> > > > >
> > > > --
> > > > EVDL
> > > >
> > > --
> > > EVDL
> > >
> >
> --
> EVDL
>
--- End Message ---
--- Begin Message ---
John Lussmyer wrote:
> A friend just sent this to me:
> http://www.indycycleonline.com/index.htm
> It's a 3 wheeler using a motorcycle as the power plant. The
> company is
> planning on selling kits.
> Wonder what kind of EV you could build from something like this? :-)
Hi John,
My guess is that you'd have to do some serious modifications before
you'd have a very good EV. But the potential is there. As is, it
carries a lot of weight in the worst place - high and to the rear. It's
probably very fast in a straight line, and probably stable at the limit
(meaning it won't tip before sliding). But it probably feels much
faster than it is in the handling department.
A three-wheeler has all its roll resistance between the two side-by-side
wheels. That means that end tends to get loose before the single wheel
end. But this one also has lots of power *and* weight on the single
wheel. It's probably drifting all the time. It would handle better
with a far more forward-biased weight distribution.
Making this a good EV would mean adding battery racks beside and in
front of the driver. That sort of destroys the pencil-thin formula car
look (and means you need a whole new body). It would need much better
front fenders than the add-ons they show. (Unless you like getting
showered by your inside front wheel on tight turns in the rain.) I'd
put lights on the fenders to help prevent a front wheel from being
removed the hard way by oncoming SUVs.
When you think of what you'd have to do to modify it, it looks simpler
to start from scratch. A three-wheel EV formula car for the street
would be wickedly fun, though.
Chris
--- End Message ---
--- Begin Message ---
* LP8.2: HTML/Attachments detected, removed from message *
--- End Message ---
--- Begin Message ---
Well it looks cool, but I think it would make a poor EV due to the lousy
aerodynamics.
Its designed to look like an Indy car and Indy cars have aerodynamics
that are worse than a brick wall.
According to NASA's website:
http://www.nas.nasa.gov/About/Education/Racecar/statistics.html
the Galmar G-92 setup for Short Oval racing has a Cd of 1.397, setup for
street racing it has a Cd of 1.141.
Compare this to the average sedan with 0.35 and 0.6 for modern big rigs.
Primary aerodynamic concern for Indy cars is holding the corners at high
speeds, low drag comes as a VERY distant second.
On Mon, 2003-03-24 at 10:36, John Lussmyer wrote:
> A friend just sent this to me: http://www.indycycleonline.com/index.htm
> It's a 3 wheeler using a motorcycle as the power plant. The company is
> planning on selling kits.
> Wonder what kind of EV you could build from something like this? :-)
>
> --
> John G. Lussmyer mailto:[EMAIL PROTECTED]
> Dragons soar and Tigers prowl while I dream....
> http://www.CasaDelGato.Com
>
--
EVDL
--- End Message ---
--- Begin Message ---
Thanks for the advice about this - however I think that I'm covered in terms
of the pack imbalance issue - I have a charger that charges each individual
battery with it's own lead, not in series.
I really don't want to plunk down the $200 for a converter, either.
Seth
----- Original Message -----
From: "Lawrence Rhodes" <[EMAIL PROTECTED]>
To: "John Wayland" <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 7:04 AM
Subject: Re: Don't tap the battery pack (was: Today's mystery question
withelectricity)
> I found a few 35 to 50 watt converters at Excess Solutions for 4 bucks
each.
> I am using two on my cart. One for the headlights and one for the running
> lights and turnsignals. Cost = 8 bucks plus wiring. Lawrence Rhodes.....
> ----- Original Message -----
> From: "John Wayland" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Sunday, March 23, 2003 3:31 PM
> Subject: Re: Don't tap the battery pack (was: Today's mystery question
> withelectricity)
>
>
> > Hello to All,
> >
> > "[EMAIL PROTECTED]" wrote:
> >
> > > At 06:48 PM 3/22/03, you wrote:
> > > >I have all of my 12V electronics - blinkers, headlights etc.
hardwired
> to
> > > >one of my batteries in my 36V 1960 electric shopper. From the
hardwire,
> it
> > > >goes through a fuse box, with a 15amp fuse on each seperate
accessory.
> > > >Everything works just fine aside from the stereo.
> > >
> > > Tapping the pack is a BAD practice. Don't do this.
> > >
> > > I have some 200 watt DC-DC converters (somewhere) that will
run
> on
> > > 36 volts. (Actually, I sold some of these to Rod Wilde. He might have
a
> few
> > > left.) Use one or more of these instead of tapping the pack.
> >
> > Those would be the Microverter moduals. Bill was good enough to let 5 of
> them come my way
> > years ago. They are about the size of a deck of playing cards, 36V in,
> 12-15V adjustable
> > out, at up to 17 amps! I use one adequately heat sinked, in the Heavy
> Metal Garden
> > Tractor, and it has performed flawlessly. I back it up with a 13 ahr
> Hawker Genesis, and
> > the combo of the 17 continuous amps from the DC-DC and the stout backup
> juice from the
> > Hawker, keeps my garden tractor's 144 watt (rms) stereo system rock'n
> hard! I set it up,
> > so that when the tractor is off, the DC-DC keeps the Hawker floating at
> 12.95V and the
> > Emeter powered up at all times...when the ign. key is on, the output
> voltage swings up to
> > 14.3V.
> >
> > > I repeat: Tapping the pack is BAD practice. It is really
tough
> on
> > > your batteries. One battery will not get enough charge and the others
> will
> > > be massively overcharged.
> >
> > Couldn't agree more.
> >
> > See Ya.....John Wayland
> >
> >
>
>
--- End Message ---
--- Begin Message ---
> > Been their done that. This idea dates back over 100 years and used to
> > be how all EVs operate.
>
> This new method has a distinct difference from the previous method. The
> batteries are grouped with one battery in the first bank, two batteries in
> the second bank, four batteries in the third bank, etc, doubling as you go
> up. The higher you go, the more steps you get. The arrangement is
> analogous to a binary counter, where the first place in the one's counter,
> the second place is the two's counter, the third place is the four's
> counter, etc. By rearranging the batteries in these groups, you get every
> step from zero to full voltage, using the minimum number of relays.
Yup and the first battery gets drained more than the second, the first
and second more than the third and so forth.
You end up running the first battery empty long before the last battery
has even started to be drained. Once the first battery is empty you
can't use the pack anymore without damaging the first battery so most of
the packs capacity never gets used.
This severely limits range.
Finally since the batteries all end up discharged to different levels
you can't use a bulk charge to charge the whole pack. You must charge
the batteries individually. This either requires a lot of individual
chargers or a lot of manual labor moving the charger around.
All and all it works, but it's a really bad idea, sorry.
>
> > The problem is you end up with discreet voltage steps instead of the
> > smooth variability of a modern PWM controller.
>
> Very true, but with enough steps, you don't notice much difference. The
> minibike has only three steps from zero to 30 mph, which is a little coarse.
> I think seven steps in that speed range will work great.
>
> > Add in the fact that
> > high current contactors are very expensive (more expensive for the set
> > than a PWM controller) and it's easy to see why almost nobody builds EVs
> > that way anymore.
>
> This is a concern that needs more research. But (as you state below) in the
> small horse power range, its really cheap. My 50 DC ampere relays were 6
> for $30 on Ebay. With a 36 volt system, that's a 1.8 KW capability. The
> relays seem to take 100 amperes ok when I'm showing off in front of the
> neighbors, but I'm sure that kind of load will eventually wear them out
> prematurely.
>
> >
> > FWIW they were still using this method in the '70s for golf carts and
> > City/Commuta cars.
> >
> > It works fine on low power setups though.
> >
> > PS Contactor REGEN only works with PM motors and shunt/sep ex motors.
> > Doesn't work worth beans with series wound motors. But then REGEN with
> > series wound motors is tough to do any way.
>
> Yes, I'm using a PM motor.
>
> >
> > On Sun, 2003-03-23 at 20:57, Mark Thomasson wrote:
> > > I invite everyone to comment on the following idea for a low tech method
> of
> > > controlling motor voltage, and thus vehicle speed. Instead of leaving
> the
> > > batteries in a monolithic lump and controlling motor voltage with a
> > > sophisticated electronic device, lets use the fact that the battery bank
> is
> > > composed of smaller units that may be rearranged with contactors to get
> > > various voltages. For example, with seven batteries in the bank, it is
> > > possible to rearrange them to get seven voltage steps, from zero volts
> to
> > > the voltage of all the batteries in series. With 15 batteries, 15 steps
> are
> > > possible. The trick is to rearrange the batteries without using an
> > > unreasonable number of contactors. See
> > > http://www.geocities.com/thomassonmj/electric_drive.html for a diagram
> of
> > > how this may be done. http://www.austinev.org/evalbum/439.html shows
> the
> > > test platform. I started small with a minibike and only 3 voltage steps
> > > (using three 12 volt batteries) in the control system. The three relays
> and
> > > a multiposition switch comprising the control system cost less than $20.
> > > Electro-mechanical relays are much easier to trouble shoot and repair
> that
> > > electronic FET's and integrated circuits, and more efficient. Solid
> state
> > > relays could also be used. Regenerative braking occurs automatically as
> you
> > > back off the throttle, or not at all if the throttle goes immediately to
> > > zero.
> > >
> > > Criticize freely... I can take it!
> > >
> > > Thanks for your feedback.
> > >
> > > Mark Thomasson
> > >
> > >
> > > ----- Original Message -----
> > > From: "1sclunn" <[EMAIL PROTECTED]>
> > > To: <[EMAIL PROTECTED]>
> > > Sent: Saturday, March 22, 2003 6:59 PM
> > > Subject: Re: AC controllers
> > >
> > >
> > > > Hi Mark
> > > ...................
> > > >
> > > > Tell us of your project? what do you want it to do?
> > > >
> > > ....................
> > >
> > --
> > EVDL
> >
>
--
EVDL
--- End Message ---
--- Begin Message ---
See more rebuttals below. Good comments. Thanks, Mark Thomasson
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: "EV" <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 12:08 AM
Subject: Re: AC controllers
> Oops, forgot to mention.
> Contactor controllers normally rearrange the pack into series/parallel
> setups.
> IE. a 48V pack of 4 12V batteries will be arranged as all four in
> parallel for 12V, two sets of two for 24V and all together for 48V. Plus
> usually a starting resistor in series with the 12V setup. This gives
> four steps, plus stop.
This old method takes nine contactors, and the resistor wastes energy.
Using eight batteries with the old method will give you four steps (5 if you
count the resistor step) and requires 21 contactors. To get more steps, the
number of contactors required quickly becomes rediculous. The new method
only uses 6 contactors for seven steps. 9 contactors for 15 steps 12
contactors for 31 steps, etc. Steps go up exponentially, but contactor
requirements go up linearly.
Also, that's a big jump from 24 to 48 volts using the old method, so you may
need the resistor in there again. The new method give the smallest
incremental steps possible all the way up without resistors.
>
> Tapping the pack at individual batteries like you suggest means that
> none of the batteries will be discharged to the same level. The first
> battery gets used all of the time and the one at the other end of the
> string hardly ever gets used.
This new method does not "tap the pack". The first battery bank gets used
every other increment. The last battery bank gets used continously after
the half way voltage is reached. See the switch table at
http://www.geocities.com/thomassonmj/motor_circuit.html for help in
visualizing this sequence.
>
> This causes the pack to become unbalanced(a bad thing). Your range will
> be limited by the first battery which will run out fairly quickly, while
> 1/2 the batteries are hardly discharged at all.
>
> Range from this setup will be about 1/4 the range of using all the
> batteries as one pack with a PWM controller or a series/parallel
> contactor controller.
In actual city traffic conditions, all the batteries get used almost
equally, because speed rarely stays the same for long. If you were able to
drive at a constant speed long enough at less than full voltage, then the
batteries would be drained unevenly.
>
> > > various voltages. For example, with seven batteries in the bank, it
is
> > > possible to rearrange them to get seven voltage steps, from zero volts
to
> > > the voltage of all the batteries in series. With 15 batteries, 15
steps are
> > > possible. The trick is to rearrange the batteries without using an
> > > unreasonable number of contactors. See
> > > http://www.geocities.com/thomassonmj/electric_drive.html for a
diagram of
> > > how this may be done. http://www.austinev.org/evalbum/439.html shows
the
> > > test platform. I started small with a minibike and only 3 voltage
steps
> > > (using three 12 volt batteries) in the control system. The three
relays and
> > > a multiposition switch comprising the control system cost less than
$20.
> > > Electro-mechanical relays are much easier to trouble shoot and repair
that
> > > electronic FET's and integrated circuits, and more efficient. Solid
state
> > > relays could also be used. Regenerative braking occurs automatically
as you
> > > back off the throttle, or not at all if the throttle goes immediately
to
> > > zero.
> > >
> > > Criticize freely... I can take it!
> > >
> > > Thanks for your feedback.
> > >
> > > Mark Thomasson
> > >
> > >
> > > ----- Original Message -----
> > > From: "1sclunn" <[EMAIL PROTECTED]>
> > > To: <[EMAIL PROTECTED]>
> > > Sent: Saturday, March 22, 2003 6:59 PM
> > > Subject: Re: AC controllers
> > >
> > >
> > > > Hi Mark
> > > ...................
> > > >
> > > > Tell us of your project? what do you want it to do?
> > > >
> > > ....................
> > >
> > --
> > EVDL
> >
> --
> EVDL
>
--- End Message ---
--- Begin Message ---
Comments from Mark Thomasson below:
----- Original Message -----
From: "1sclunn" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 3:30 AM
Subject: Re: AC controllers
> Sounds like money my be a problem here. The PWM also converts batterie
> volts into motor amps this is very nice. When I blow my first Curtis which
I
> got from solar car I drove around with the pack set up as two strings of
60v
> , no steps just on and off( say the controller will be hear any day ,
over
> and over ) . I truned the key on and slipped the clutch and used the gears
> to adjust the speed. I was very supprized at the distance I losted or how
> much more ah I used to make the same trips.
Clutch slipping is inefficient. If you slip 50% (output RPM vs input RPM),
you are dissipating half your energy in the clutch. If you are slipping 90%,
90% of the energy is lost in the clutch.
> there is also the problem of charging the batteries.
Yes, this arrangement might need a separate charger for each bank. For a
seven step controller, that means three charger. Four charger for a 15 step
controller.
> Is money the reason your concidering this>?
I'm just looking for better ways to do things. This method does seem to be
cheaper for low power vehicles, like motorcycles, but maybe not for the big
iron. It is a simple, low tech method. Efficiency is higher because the
voltage drop across the contactors is very small (.004 ohms for my setup).
The "cool" factor may not be as high as the electronic controllers.
> ----- Original Message -----
> From: "Peter VanDerWal" <[EMAIL PROTECTED]>
> To: "EV" <[EMAIL PROTECTED]>
> Sent: Sunday, March 23, 2003 9:18 PM
> Subject: Re: AC controllers
>
>
--- End Message ---
--- Begin Message ---
Thanks, good comments. See my replies below. Mark Thomasson
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, March 24, 2003 2:28 AM
Subject: Re: AC controllers
> Mark Thomasson wrote:
> > I invite everyone to comment on the following idea for a low tech
> > method of controlling motor voltage, and thus vehicle speed...
> > use the fact that the battery bank is composed of smaller units
> > that may be rearranged with contactors to get various voltages...
> > The trick is to rearrange the batteries without an unreasonable
> > number of contactors. See
> >
> > http://www.geocities.com/thomassonmj/electric_drive.html
> > for a diagram of how this may be done.
>
> The first problem is that you are not loading the batteries equally.
> Thus, they will discharge at different rates. I suppose you could rig
> your control system to monitor individual batteries, and only allow
> steps to be selected when that battery has enough charge. But that would
> be rather unpleasant for the driver (can drive at 20 mph or 40 mph, but
> not 30 mph because the battey for that step is dead).
In actual city traffic conditions, all the batteries get used almost
equally, because speed rarely stays the same for long. If you were able to
drive at a constant speed long enough at less than full voltage, then the
batteries would be drained unevenly. See the switch table at
http://www.geocities.com/thomassonmj/motor_circuit.html for help in
visualizing this sequence.
>
> Having the batteries discharge unequally also complicates things when
> charging.
No disagreement about this.
>
> Next problem; you still have a lot of contactors. The way they are
> arranged, if one fails shorted, it could be disastrous to close the next
> one. You would need a lot of fuses, and/or "smart" control logic to
> detect a stuck switch and so not close the next one.
Good point. Each battery bank should be fused. This means 3 fuses for a
seven step controller. 4 fuses for a 15 step controller. 5 fuses for a 31
step controller, etc.
>
> This problem has been studied for a very long time by some great minds.
> You might want to look at some of their solutions.
Exactly, that's why I'm asking you guys for input!
>
> For example, the batteries can be switch in series-parallel combinations
> so the load is always divided equally between them. If you had 12 6v
> batteries, for example, they can be wired:
>
> 6v - all in parallel
> 12v - 6 strings of 2
> 18v - 4 strings of 3
> 24v - 3 strings of 4
> 36v - 2 strings of 6
> 72v - all in series
This arrangement would take 33 contacts and gives only 6 steps. If you are
willing to give up on the symetry, you could get all 12 evenly spaced steps.
Perfect balancing of battery discharge would be possible, a big advantage.
The new method would give 15 steps with 15 6v batteries, but only use 9
relays (72% fewer). Balancing of battery discharge would depend on the
natural variability of driving speed.
>
> The classic series-parallel switch is a single contactor with 3
> contacts:
> ______________________
> + __|__ K1b |
> battery 1 ___ normally closed / K1c
> |__________/___________| normally open
> | K1a __|__+
> / normally open ___ battery 2
> |______________________| -
>
> If you don't need to do regen (carry current in both directions), then
> K1a and K1c can be replaced by a big diode. Then series-parallel
> switching is done with a single SPST contactor.
The new method also lets you reduce relay count by using doides, but diodes
always have a forward biase voltage drop (~.7 v for silicon) and therefore
energy loss, more significant in low voltage systms than high voltage ones.
> --
> Lee A. Hart Ring the bells that still can ring
> 814 8th Ave. N. Forget your perfect offering
> Sartell, MN 56377 USA There is a crack in everything
> leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
>
--- End Message ---
--- Begin Message ---
For about three days my EV Discussion List messages have been coming
in digest form. And the messages are attachments which I can't open.
I can read the individual messages in the Yahoo! Group, EVList which is
a poorer way to handle messages. Is this my unique problem or are
others having the same problem?
Tom Shay
--- End Message ---
--- Begin Message ---
I subscribe to the digest, and am getting several a day, in
50K chunks. Each digest has HTML attached messages, and
about 90% redundent quotes.
Anyone know if I can "suspend" my subscription on weekends
when I am gone, or will I have to un-sub and re-sub myself?
I'm not sure about the purpose of the list, when the
yahoo group (which I find is much easier to read) exists.
In the group, you can set digest, individual, or web reading.
Mike ( in Los Angeles, no EV, and none in sight to be
able to buy from a mfg that I can afford. )
--- In [EMAIL PROTECTED], "Thomas Shay" <[EMAIL PROTECTED]> wrote:
> For about three days my EV Discussion List messages have been
coming
> in digest form. And the messages are attachments which I can't
open.
> I can read the individual messages in the Yahoo! Group, EVList
which is
> a poorer way to handle messages. Is this my unique problem or are
> others having the same problem?
>
> Tom Shay
__________________________________________________
Do you Yahoo!?
Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop!
http://platinum.yahoo.com
--- End Message ---
--- Begin Message ---
At 12:19 PM 3/24/2003 -0800, Mike Burgess stated:
I subscribe to the digest, and am getting several a day, in
50K chunks.
This is a busy list.
Each digest has HTML attached messages, and
about 90% redundent quotes.
That's just the people who don't bother properly editing their replies.
Anyone know if I can "suspend" my subscription on weekends
when I am gone, or will I have to un-sub and re-sub myself?
Probably have to do it yourself, but you can probably just create a couple
of messages and re-send them as needed.
I'm not sure about the purpose of the list, when the
yahoo group (which I find is much easier to read) exists.
In the group, you can set digest, individual, or web reading.
Yahoo is just an archive for this group. Any replies sent to that list
won't be seen my most people.
Also, Yahoo adds a bunch of advertising which most people don't want to see.
Many people (like me) just setup an Email filter to put ALL the EV list
items in their own mail folder. This makes reading and/or ignoring
messeages MUST easier.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.Com
--- End Message ---
