EV Digest 6799
Topics covered in this issue include:
1) RE: Motor needed
by [EMAIL PROTECTED]
2) RE: direct drive or transmission?
by Chip Gribben <[EMAIL PROTECTED]>
3) RE: direct drive or transmission?
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
4) Re: Speaking of battery announcements ... What about Firefly
by Jeff Shanab <[EMAIL PROTECTED]>
5) Re: Main Contactor Ebay Search Criteria
by Jeff Major <[EMAIL PROTECTED]>
6) Re: Speaking of battery announcements ... What about Firefly
by Mark Ward <[EMAIL PROTECTED]>
7) Re: 42 more to go! [slightly OT now!]
by "peekay" <[EMAIL PROTECTED]>
8) Re: Main Contactor Ebay Search Criteria
by "damon henry" <[EMAIL PROTECTED]>
9) Re: Charging Stations
by [EMAIL PROTECTED]
10) Re: Main Contactor Ebay Search Criteria
by "George Swartz" <[EMAIL PROTECTED]>
11) Re: Speaking of battery announcements ... What about Firefly
by [EMAIL PROTECTED]
12) ElectroMetropolitan
by Daniel Eyk <[EMAIL PROTECTED]>
13) Re: ElectroMetropolitan
by Jim Husted <[EMAIL PROTECTED]>
14) Re: Main Contactor Ebay Search Criteria
by "damon henry" <[EMAIL PROTECTED]>
15) RE: direct drive or transmission?
by Jeff Major <[EMAIL PROTECTED]>
16) Direct drive
by "Dustin Stern" <[EMAIL PROTECTED]>
17) Re: Direct drive
by Mark Farver <[EMAIL PROTECTED]>
18) Re: article: Electric Motorcycle: Test Drive (with Video)
by Steven Lough <[EMAIL PROTECTED]>
19) Re: Solectra/Azure - A123 response + A Great Idea!!
by Tehben Dean <[EMAIL PROTECTED]>
20) Magnetic motor bike & other youtube electric bike videos.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
21) Re: direct drive or transmission?
by Lee Hart <[EMAIL PROTECTED]>
22) Re: Reality check, Re: Permanent magnet motor question
by Lee Hart <[EMAIL PROTECTED]>
23) Re: Reality check, Re: Permanent magnet motor question
by Lee Hart <[EMAIL PROTECTED]>
24) Re: Main Contactor Ebay Search Criteria
by Lee Hart <[EMAIL PROTECTED]>
25) Re: Electropolitan smokes tire, misses record
by "Dave Wilker" <[EMAIL PROTECTED]>
26) Re: Reality check, Re: Permanent magnet motor question
by "(-Phil-)" <[EMAIL PROTECTED]>
27) Re: Series motor regen with CC? and Semi-electronic controllers?
by Jeff Major <[EMAIL PROTECTED]>
--- Begin Message ---
Data will tell. I am and will keep detailed records. If I find a motor and
complete the project and it does not fail in the first year, we will know the
answer.
I will know a partial answer in two weeks as I am about to take two 650 drives
and I have installed the battery boxes and I have 300 lbs of batteries on
board. We will see if I can measure a difference as I have driven route many
times.
via Treo
David Hrivnak
-----Original Message-----
From: Tim Humphrey <[EMAIL PROTECTED]>
Subj: RE: Motor needed
Date: Mon May 21, 2007 9:46 am
Size: 876 bytes
To: EV <ev@listproc.sjsu.edu>
<snip>
But if
> you are sometimes driving 650 miles a day, and carrying an extra 800 lbs,
> are you really going to be saving anything in the long run?
>
> Marty
>
I'm sure you have an ICE powered vehicle....
How much does carrying around 4 adult passengers (800 lbs) affect it's MPG?
In a dragster, weight plays an important part of the total vehicular equation.
In a "normal" vehicle not so much so. "WE" have a tendancy on this list to
"over-analyze" things. Take the discussion about bellypans for example; Do you
think it really matters which is lighter, cloroplast, aluminum, or
polyethelene. The three are so close it is a complete waste of time to even
consider their weight as a deciding factor.
Don't get me wrong, I'm not suggesting to load up your vehicle with dead weight
either, just don't get hung up on it.
--
Stay Charged!
Hump
I-5, Blossvale NY
--- End Message ---
--- Begin Message ---
There was that Swedish Chef on the Muppets.
Chip
On May 21, 2007, at 9:37 AM, Electric Vehicle Discussion List wrote:
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
Date: May 20, 2007 8:19:13 PM EDT
To: ev@listproc.sjsu.edu
Subject: RE: direct drive or transmission?
Wow, what a storm this opened up.
I'm sorry John, but if we go with your definitions of "direct
drive" then
the term becomes so ambiguous as to be useless.
When someone asks "what kind of motor do I need with direct drive"
or "is
direct drive better than ..."
Now we have to ask them which kind of "direct drive" they mean?
Seems to me that it would be better if folks were a bit more
specific from
the begining and I feel that we <as a group> can encourage that by
using
more specific terms, and giving more specific definitions to the
terms we
use.
But if you want to push for more ambiguity, I guess we can go that
way too.
P.S. I thought it was the Swiss who were traditionally neutral? I'm
probably wrong, plus I don't recall any Swiss Muppets.
--- End Message ---
--- Begin Message ---
He was the guy who did the BORK BORK BORK!!!!!
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Chip Gribben
Sent: Monday, May 21, 2007 9:56
To: ev@listproc.sjsu.edu
Subject: RE: direct drive or transmission?
There was that Swedish Chef on the Muppets.
Chip
On May 21, 2007, at 9:37 AM, Electric Vehicle Discussion List wrote:
> From: "Peter VanDerWal" <[EMAIL PROTECTED]>
> Date: May 20, 2007 8:19:13 PM EDT
> To: ev@listproc.sjsu.edu
> Subject: RE: direct drive or transmission?
>
>
> Wow, what a storm this opened up.
>
> I'm sorry John, but if we go with your definitions of "direct drive"
> then the term becomes so ambiguous as to be useless.
> When someone asks "what kind of motor do I need with direct drive"
> or "is
> direct drive better than ..."
> Now we have to ask them which kind of "direct drive" they mean?
>
> Seems to me that it would be better if folks were a bit more specific
> from the begining and I feel that we <as a group> can encourage that
> by using more specific terms, and giving more specific definitions to
> the terms we use.
> But if you want to push for more ambiguity, I guess we can go that way
> too.
>
> P.S. I thought it was the Swiss who were traditionally neutral? I'm
> probably wrong, plus I don't recall any Swiss Muppets.
--- End Message ---
--- Begin Message ---
I looked through their site briefly but didn't see some basic info,
Wh/kg, wh/liter,w/kg, cycle life/C rate, (not to mention price and
Availability.)
Maybe it is not obvious, Do you have that info? (lots of adjitives, I
need some specs.)
--- End Message ---
--- Begin Message ---
Martin,
I have found a few using albright contactor, kilovac,
power relay. Just play around with it and every once
in awhile, you find something good. Seller ohwags has
some occasionally, but nothing now.
Jeff
--- Martin Winlow <[EMAIL PROTECTED]> wrote:
> Can anyone suggest a search string for Ebay to find
> a (cheap) main
> contactor? Are there any specific types or
> make/model I can look for? Or
> are there just too many to make this easy?
>
> Thanks, MW.
>
>
____________________________________________________________________________________Looking
for a deal? Find great prices on flights and hotels with Yahoo! FareChase.
http://farechase.yahoo.com/
--- End Message ---
--- Begin Message ---
It looked into them over a year ago, read all the hype and decided that with no
specifics they are possibly a hoax. I don't know if the company is publicly
traded, but their shareholders are not going to be happy if they keep promising
something without supplying it. I even emailed them with some questions, but
they never even answered. Sent them by two different email accounts.
How can you get potential customers with no engineering data, specs, cost
projections, etc?
I could be wrong, but these make good urban legend material.
--- Jeff Shanab <[EMAIL PROTECTED]> wrote:
> I looked through their site briefly but didn't see some basic info,
> Wh/kg, wh/liter,w/kg, cycle life/C rate, (not to mention price and
> Availability.)
>
> Maybe it is not obvious, Do you have that info? (lots of adjitives, I
> need some specs.)
>
--- End Message ---
--- Begin Message ---
that's a real cute video .. no wonder it is a
li'l short of 50 million views !
..peekay
----- Original Message -----
From: "Ian Hooper" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, May 21, 2007 2:25 PM
Subject: Re: 42 more to go! [slightly OT now!]
> You'd have to beat 48.9 million:
>
> http://youtube.com/watch?v=dMH0bHeiRNg
>
> On 21/05/2007, at 4:32 PM, Mike Willmon wrote:
>
> > I barely got to it when I read this and you were already 76 over 100k.
> > Anyone know how many views would be a record for You Tube?
> >
> > Mike,
> > Anchorage, Ak.
> >
> >> -----Original Message-----
> >> From: [EMAIL PROTECTED] [mailto:owner-
> >> [EMAIL PROTECTED]
> >> Behalf Of Bill Dube
> >> Sent: Sunday, May 20, 2007 8:44 PM
> >> To: ev@listproc.sjsu.edu
> >> Subject: 42 more to go!
> >>
> >>
> >> If 42 more people look at the KillaCycle Las Vegas "plasma" video, it
> >> will go over 100,000 views.
> >> http://www.youtube.com/watch?v=3dRpAZci9m0
> >> The Firebird video is over 94,000 views as well, so a few thousand
> >> more will push it over 100,000
> >> http://www.youtube.com/watch?v=GDHJNG2PngQ
> >>
> >> Bill Dube'
> >>
> >>
> >
> >
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.5.467 / Virus Database: 269.7.4/811 - Release Date: 5/18/2007
3:50 PM
>
>
--- End Message ---
--- Begin Message ---
Look at item 150122532092 on ebay. I bought a few of these a couple of
months ago, and though they are not the standard EV contactors people
usually use, they are quite heavy duty. The contacts are about the size of
a nickel, and the coils draw about 2 amps at 24 volts. I don't have a data
sheet for them but they have 200 amps printed on the side which is likely a
continous rating. They look like they should be able to handle more current
then the Albright SW180 I have, as the actual contacts are quite a bit
larger. Anyway, you can't hardly go wrong for the price.
damon
From: Jeff Major <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: Main Contactor Ebay Search Criteria
Date: Mon, 21 May 2007 07:39:16 -0700 (PDT)
Martin,
I have found a few using albright contactor, kilovac,
power relay. Just play around with it and every once
in awhile, you find something good. Seller ohwags has
some occasionally, but nothing now.
Jeff
--- Martin Winlow <[EMAIL PROTECTED]> wrote:
> Can anyone suggest a search string for Ebay to find
> a (cheap) main
> contactor? Are there any specific types or
> make/model I can look for? Or
> are there just too many to make this easy?
>
> Thanks, MW.
>
>
____________________________________________________________________________________Looking
for a deal? Find great prices on flights and hotels with Yahoo! FareChase.
http://farechase.yahoo.com/
_________________________________________________________________
Catch suspicious messages before you open themwith Windows Live Hotmail.
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_protection_0507
--- End Message ---
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--- Begin Message ---
ebay contactor is only good for low voltage, since it does not have blow
outs. very dangerous to use on 120vdc or 144vdc systems.
On Mon, 21 May 2007 15:14:24 +0000, damon henry wrote
> Look at item 150122532092 on ebay. I bought a few of these a couple
> of months ago, and though they are not the standard EV contactors
> people usually use, they are quite heavy duty. The contacts are
> about the size of a nickel, and the coils draw about 2 amps at 24
> volts. I don't have a data sheet for them but they have 200 amps
> printed on the side which is likely a continous rating. They look
> like they should be able to handle more current then the Albright
> SW180 I have, as the actual contacts are quite a bit larger. Anyway,
> you can't hardly go wrong for the price.
>
> damon
>
> >From: Jeff Major <[EMAIL PROTECTED]>
> >Reply-To: ev@listproc.sjsu.edu
> >To: ev@listproc.sjsu.edu
> >Subject: Re: Main Contactor Ebay Search Criteria
> >Date: Mon, 21 May 2007 07:39:16 -0700 (PDT)
> >
> >
> >Martin,
> >
> >I have found a few using albright contactor, kilovac,
> >power relay. Just play around with it and every once
> >in awhile, you find something good. Seller ohwags has
> >some occasionally, but nothing now.
> >
> >Jeff
> >
> >
> >
> >--- Martin Winlow <[EMAIL PROTECTED]> wrote:
> >
> > > Can anyone suggest a search string for Ebay to find
> > > a (cheap) main
> > > contactor? Are there any specific types or
> > > make/model I can look for? Or
> > > are there just too many to make this easy?
> > >
> > > Thanks, MW.
> > >
> > >
> >
> >
> >
> >
>
>____________________________________________________________________________
________Looking
> >for a deal? Find great prices on flights and hotels with Yahoo! FareChase.
> >http://farechase.yahoo.com/
> >
>
> _________________________________________________________________
> Catch suspicious messages before you open themwith Windows Live
> Hotmail. http://imagine-windowslive.com/hotmail/?locale=en-
us&ocid=TXT_TAGHM_migration_HM_mini_protection_0507
--- End Message ---
--- Begin Message ---
>>>>> "Mark" == Mark Ward <[EMAIL PROTECTED]> writes:
Mark> I don't know if the company is publicly traded, but their
Mark> shareholders are not going to be happy if they keep promising
Mark> something without supplying it.
I believe they are still wholly owned by Caterpillar (?). I sent them a
note a week or two ago. They said they would have something in four to six
weeks and to contact them again in that timeframe. I'll see what they have
to say then. Presumably a NDA will not be required. ;-)
--
Skip Montanaro - [EMAIL PROTECTED] - http://www.webfast.com/~skip/
--- End Message ---
--- Begin Message ---
Does anyone know if there is a website where someone
could see this car? It would be fun to see it.
Daniel Eyk
Vancouver, Wa.
Electric S-10 project
E-15 project
____________________________________________________________________________________
Food fight? Enjoy some healthy debate
in the Yahoo! Answers Food & Drink Q&A.
http://answers.yahoo.com/dir/?link=list&sid=396545367
--- End Message ---
--- Begin Message ---
Here you go
http://www.powerofdc.com/photos/57electropolitan_640.jpg
--- Daniel Eyk <[EMAIL PROTECTED]> wrote:
> Does anyone know if there is a website where someone
> could see this car? It would be fun to see it.
>
> Daniel Eyk
> Vancouver, Wa.
>
> Electric S-10 project
> E-15 project
>
>
>
>
____________________________________________________________________________________
> Food fight? Enjoy some healthy debate
> in the Yahoo! Answers Food & Drink Q&A.
>
http://answers.yahoo.com/dir/?link=list&sid=396545367
>
>
____________________________________________________________________________________
Don't pick lemons.
See all the new 2007 cars at Yahoo! Autos.
http://autos.yahoo.com/new_cars.html
--- End Message ---
--- Begin Message ---
I suppose without a data sheet it is hard to say for sure. There are other
things besides magnetic blowouts to help extinguish an arc, but this sounds
like a good observation. In my case I am only doing 72 volts, so these
should work fine for me.
damon
From: "George Swartz" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: Main Contactor Ebay Search Criteria
Date: Mon, 21 May 2007 08:20:45 -0700
ebay contactor is only good for low voltage, since it does not have blow
outs. very dangerous to use on 120vdc or 144vdc systems.
On Mon, 21 May 2007 15:14:24 +0000, damon henry wrote
> Look at item 150122532092 on ebay. I bought a few of these a couple
> of months ago, and though they are not the standard EV contactors
> people usually use, they are quite heavy duty. The contacts are
> about the size of a nickel, and the coils draw about 2 amps at 24
> volts. I don't have a data sheet for them but they have 200 amps
> printed on the side which is likely a continous rating. They look
> like they should be able to handle more current then the Albright
> SW180 I have, as the actual contacts are quite a bit larger. Anyway,
> you can't hardly go wrong for the price.
>
> damon
>
> >From: Jeff Major <[EMAIL PROTECTED]>
> >Reply-To: ev@listproc.sjsu.edu
> >To: ev@listproc.sjsu.edu
> >Subject: Re: Main Contactor Ebay Search Criteria
> >Date: Mon, 21 May 2007 07:39:16 -0700 (PDT)
> >
> >
> >Martin,
> >
> >I have found a few using albright contactor, kilovac,
> >power relay. Just play around with it and every once
> >in awhile, you find something good. Seller ohwags has
> >some occasionally, but nothing now.
> >
> >Jeff
> >
> >
> >
> >--- Martin Winlow <[EMAIL PROTECTED]> wrote:
> >
> > > Can anyone suggest a search string for Ebay to find
> > > a (cheap) main
> > > contactor? Are there any specific types or
> > > make/model I can look for? Or
> > > are there just too many to make this easy?
> > >
> > > Thanks, MW.
> > >
> > >
> >
> >
> >
> >
>
>____________________________________________________________________________
________Looking
> >for a deal? Find great prices on flights and hotels with Yahoo!
FareChase.
> >http://farechase.yahoo.com/
> >
>
> _________________________________________________________________
> Catch suspicious messages before you open themwith Windows Live
> Hotmail. http://imagine-windowslive.com/hotmail/?locale=en-
us&ocid=TXT_TAGHM_migration_HM_mini_protection_0507
_________________________________________________________________
More photos, more messages, more storageget 2GB with Windows Live Hotmail.
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--- End Message ---
--- Begin Message ---
I think this should be the way to go.
Jeff
--- Roger Stockton <[EMAIL PROTECTED]> wrote:
> Perhaps the compromise middle ground is to use
> direct drive to refer to
> all drive configurations with a fixed reduction
> ratio between the
> motor(s) and wheel(s), and no means of decoupling
> the motor from the
> wheel rather than the strictest definition of only
> such systems with a
> 1:1 ratio between the motor and wheel?
>
> Cheers,
>
> Roger.
____________________________________________________________________________________Be
a better Globetrotter. Get better travel answers from someone who knows.
Yahoo! Answers - Check it out.
http://answers.yahoo.com/dir/?link=list&sid=396545469
--- End Message ---
--- Begin Message ---
Peter,
As I'm the original solicitor of the question regarding whether "direct drive"
is better than a transmission, I thought I'd respond.
(Originally, I thought direct drive meant electric motor to output wheels via
fixed gearing. I figured this would be valid regardless of how one implemented
coupling of the motor to the output wheels. In my case I have an intermediate
shaft. But in most instances, I'd have thought you'd ALWAYS have some fixed
gearing in a direct drive. It seems natural to assume you can vary the gear
head on a direct coupling between a motor and a diff, for instance. And if you
have a diff, that you might vary the ratio in the diff, which I though amounted
to the same thing.)
Peter, in your email you ask me to provide more information. I provided what I
thought was a detailed break down of my vehicle, including likely weight,
wattage per mile, type of controller, type of motor, and battery configuration.
I suppose I could have supplied the tire size, but I'll have to check at home
for that.
I'm not sure how I could have made my email more specific? I'll be happy to
add more specificity as I really need to make a design decision soon. The way
I see it I have 3 choices:
1. No transmission. Call it what you will. I will gear the coupling to
maximize a single Impulse or Warp 9.
2. No transmission. 2 Impulse 9s hooked to the same intermediate shaft using
different fixed rations. If possible, no clutches, but the ability to use the
most suitable motor as needed.
3. Transmission and single 9" motor. This is a tough call as my "engine bay"
isn't standard and doesn't accomodate transmissions easily - but I can and may
adapt this approach. This does suck up valuable battery space though. An MR-2
transmission would take up a great deal of free space in my three wheeler.
Again, to recap, I'm currently planning a ~180v system with a Zilla hv1k and
21/2200 lbs loaded max weight. For an idea of the drive train configuration,
you can see the vehicle at www.vortexplans.com. If the group would like
additional details, I'm happy to provide those, but I need to know what to
provide. So far I've received conflicting emails that transmission-less
vehicles eat twice the power, and that a transmission isn't necessary in a
vehicle of my weight class, adding too much complexity and weight for the gain.
v/r,
Dustin
-------------
Peter's post: (sorry, I'm on list serve, so I currently can't respond to emails
until I get the entire list)
Wow, what a storm this opened up.
I'm sorry John, but if we go with your definitions of "direct drive" then
the term becomes so ambiguous as to be useless.
When someone asks "what kind of motor do I need with direct drive" or "is
direct drive better than ..."
Now we have to ask them which kind of "direct drive" they mean?
Seems to me that it would be better if folks were a bit more specific from
the begining and I feel that we <as a group> can encourage that by using
more specific terms, and giving more specific definitions to the terms we
use.
But if you want to push for more ambiguity, I guess we can go that way too.
P.S. I thought it was the Swiss who were traditionally neutral? I'm
probably wrong, plus I don't recall any Swiss Muppets.
--- End Message ---
--- Begin Message ---
Dustin Stern wrote:
Again, to recap, I'm currently planning a ~180v system with a Zilla hv1k and
21/2200 lbs loaded max weight. For an idea of the drive train configuration,
you can see the vehicle at www.vortexplans.com. If the group would like
additional details, I'm happy to provide those, but I need to know what to
provide. So far I've received conflicting emails that transmission-less
vehicles eat twice the power, and that a transmission isn't necessary in a
vehicle of my weight class, adding too much complexity and weight for the gain.
Another option... I know the vortex is designed to use a motorcycle as
the engine and rear driven wheel, but could you modify the design to
drive the two front wheels instead.
The Doran 3 wheeler does it this way, the front suspension is a stock
FWD system from a Subaru (in the one I saw) with transmission. The rear
wheel freewheels.
http://www.rqriley.com/doran.html
http://www.austinev.org/evalbum/559
Mark Farver
--- End Message ---
--- Begin Message ---
These folks were at the Microsoft Campus for the Cascadia Institute
Conference on PHEV's a couple of weeks ago. ( HYBRIDTECHNOLOGIES )
I met Frank Ziegler, sales directaor, and he let me take this very bike
round the block. Seemed to have a lot of torque to me. And at a Price
Point of $3500. with Li-Ion batteries almost seems too good to be true.
They had also brought a Li-Ion Smart Car conversion. Im wondering if
any one has bought any of their products. I would not want to be #1.
They are out of Nv. and N.C. ( www.hybridtechnologies.com )
Any more INFO .... any one ???
--
Steven S. Lough, Pres.
Seattle EV Association
6021 32nd Ave. N.E.
Seattle, WA 98115-7230
Day: 206 850-8535
Eve: 206 524-1351
e-mail: [EMAIL PROTECTED]
web: http://www.seattleeva.org
--- End Message ---
--- Begin Message ---
Azure responded fast to my email and sent me pdf's on the controller
and motor like I asked.
Also a123 responded and said:
"Good morning. Our capacity for the 32 series cells is committed to OEM
programs through 2007. Thanks."
So I suddenly thought... why don't we all form a company, UEVH.inc
(United Electric Vehicle Hobbyist's incorporated) or something and
then we can make large orders of "OEM only blah blah" products (think
lithium batteries) for all the members and anyone else we can sell to
at a markup?
Or we can not sell and be a non-profit... I don't no what the
benefits are to that, but I'm sure there are some.
Think, a non-profit promoting environmentally friendly
transportation.... there has got to be government subsidies or
something... well thats already gone to Exxon, Walmart and Corn
growing I guess. (It was a good idea ;)
Tehben
"United We Stand" :)
--- End Message ---
--- Begin Message ---
http://www.youtube.com/watch?v=trws3k9vq6M&NR=1 This and related videos are
growing fast. There are many manufacturers developing & producing electric
vehicles of the two wheel variety. Seems they are making the best of
youtube for advertising. Lawrence Rhodes.....
--- End Message ---
--- Begin Message ---
Dustin Stern wrote:
Can I solicit some comments about whether I should opt for direct
drive or a transmission in my EV project?
With a light vehicle (2200 lbs), powerful controller (Zilla 1K), and
only one drive wheel (3-wheel Vortex), I think a single fixed ratio will
be fine. Depending on your rear tire diameter, something close to a 5:1
ratio would give you a 70+mph top speed and be able to spin the tire on
dry pavement.
The Warp 9" motor will be fine if you include a blower to provide
adequate cooling at low speeds where its internal fan isn't working.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
(-Phil-) wrote:
I don't believe a contactor controller can be much [more] efficient
than PWM.
Not "much" more efficient; but a *little* more efficient. Like I said,
99% vs. 94%. That's only 5% better, which isn't enough to even notice
without careful measurement.
Yes, at full throttle, the loss is less, but most of the time we are
pushing less than full.
Except that any decent contactor controller will rewire the batteries
and/or motors in various series/parallel combinations to achieve speed
control. The resistors are out of the circuit for all speeds except
while starting from a dead stop. The resistors are only in the circuit
for a couple seconds, and only at very low voltages, so the power lost
in them is negligible.
Also, just getting up to full throttle is a problem, as it will be
less smooth, and we have more resistive losses to deal with the
higher inrush currents.
Dumping a motor to full on through a contactor causes more heating in
the batteries, cables, and motor windings. If you use a resistor to
soften the start, then that's obvious loss!
The inrush current is actually pretty small with a series motor. Were
you expecting it to be large?
A series motor behaves roughly like a resistor whose resistance is
proportional to rpm. For a 2:1 step in voltage, the current also makes a
2:1 step (because the apparent motor resistance is fixed). Its
inductance also delays and softens the rise and fall of current.
Suppose you want to drive at 40 mph, but your contactor controller has
only steps at 30 mph and 45 mph. Say 30 mph = 3000 rpm = 100 amps at
36v; then your motor's equivalent resistance is 36v/120a = 0.3 ohms.
Now you step down to the next "click", and the voltage doubles to 72v.
Since rpm hasn't changed (yet), motor equivalent resistance also won't
changed; it's still 0.3 ohms. So motor current wants to go to I =
72v/0.3ohms = 240 amps.
Double the current means roughly double the torque; the car starts to
speed up. But as it does, motor rpm and thus motor equivalent resistance
also rise. So your speed won't double; it goes up perhaps 50% to 45 mph.
The weight of the car and the torque of the motor will make this take
5-10 seconds. That's a pretty gradual acceleration.
At 40 mph (your target speed), the motor is at 4000 rpm, so its
resistance has gone up to 0.4 ohms. The current is 72v / 0.4ohms = 180
amps. 45 mph is 4500 rpm, 0.45 ohms, and 160 amps.
The same thing happens when you let up the pedal one "click" to slow
back down. It takes at least as long as it did to speed up, another 5-10
seconds. To maintain an average of 40 mph, you wind up cycling back and
forth between 36v and 72v with a 10-20 second cycle, with gradual speed
increases and decreases. A passenger may here the clicks, but probably
won't notice the speed changes or feel the torque pulsations.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
(-Phil-) wrote:
Also, all Curtis controllers I've looked at, don't have diodes in the
path, just the MOSFETs.
The MOSFETs are in the path during controller on-time, and the diodes
are in the path during the off-time. In effect, they are in series as
far as motor current is concerned. Except at full-on, you need to
consider the voltage drop of both of them.
Go through the math; you'll find out that indeed, the conduction losses
are proportional to the the *sum* of the diode and transistor voltage drops.
MOSFETs typically don't have a .5v loss!
They act like resistors, and have a drop proportional to current. The
MOSFETs in a controller are usually sized to have somewhere near a 0.5v
drop. For example, the Curtis 1221-74xx (72-120v) controller specs a
0.5v drop per 100 amps, and the 1231 is 0.3v per 100 amps. 100-200 amps
is the normal cruising current for EVs using these controller.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
damon henry wrote:
Look at item 150122532092 on ebay.
That's a good high-current contactor, but it's not built for high
voltages. It would be good for 72v and lower, or with multiple units in
series (like for a contactor controller).
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Didn't these cars have the drivetrain from MG? if so, maybe some MG parts?
David C. Wilker Jr.
USAF (RET)
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Saturday, May 19, 2007 8:15 PM
Subject: Re: Electropolitan smokes tire, misses record
Thanks for the info. I wonder if anyone makes a spool to fit a 1956
Metropolitan rear end. I haven't even looked.
The car was always so heavy that it had plenty of traction.
Shawn
-----Original Message-----
From: [EMAIL PROTECTED]
To: ev@listproc.sjsu.edu
Sent: Sat, 19 May 2007 10:44 PM
Subject: RE: Electropolitan smokes tire, misses record
The way I read the rule is that you CAN use a posi, LS or locker. You
just have
to retain the stock transaxle or rear end
housing. I even think you can run race axles if needed, as long as the
housing
remains stock.
<snip>
Street Conversion Class (SC)
The Street Conversion (SC) class is for basic street legal and licensed
conversions that have not been modified for racing.
.....
Section 4: Drivetrain...
....Heavy duty and or modified rear axles, heavy duty and or modified
front
drive transaxles, and heavy duty and or modified rear
transaxles assemblies allowed so long as the stock housing is retained.
Heavy
duty and or modified transmissions
allowed.....Welded spider gears and spools not allowed...
<snip>
I take this to mean that since welded gears and spools are explicitly
excluded,
then everything else like posi, LS and lockers are
allowed :-)
Get some traction man ;-)
Shawn Lawless wrote:
It doesn't look like the SC rules allow us to do much to the rear end
like a posi or spool but the least we can do is some new tires for
Power of DC. What a shame to have that kind of torque and nowhere to
put it.
________________________________________________________________________
AOL now offers free email to everyone. Find out more about what's free
from AOL at AOL.com.
--- End Message ---
--- Begin Message ---
Okay, I'll give you that on a contactor controller that complex. I just
drew a schematic for one like you describe, and it's got a lot of contacts!
Interesting exercise.... But it offends my "sense of engineering" to want
to put something like that in my EV. =)
I noticed you'd also have problems with running a DC-DC converter to power
all those coils. You'd pretty much be resigned to an Aux battery to run
them, and if you had to have the DC-DC; then only switch it in either at the
highest voltage or maybe also "idle". Tricky! Lots of arcing because of
the front-end capacitors in the DC-DC though.
Soon I'm going to put together a siamese motor configuration with a large PM
DC and a 3-phase AC motor so I can use the resulting test-bed to develop my
own AC controller. I've built successful DC controllers. The last one I
made was controlled by a microcontroller (AVR) and was a half-bridge
configuration, so my low-side MOSFETs eliminated any diode loss. (built for
a PM motor) The devices on the market now enable much better specs than you
are quoting for the Curtis designs. Run low-side switching instead of
diodes and use state-of-the-art MOSFETs and lots of them, and I'll trump
your contactor controller efficiency.... :-p
For my 3-phase inverter I'm going to start out with lower voltage and use
MOSFETs then maybe move to a higher voltage and play with IGBTs. Never done
that yet! Look forward to liberating some blue smoke here and there....
-Phil
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, May 21, 2007 10:18 AM
Subject: Re: Reality check, Re: Permanent magnet motor question
(-Phil-) wrote:
I don't believe a contactor controller can be much [more] efficient than
PWM.
Not "much" more efficient; but a *little* more efficient. Like I said,
99% vs. 94%. That's only 5% better, which isn't enough to even notice
without careful measurement.
Yes, at full throttle, the loss is less, but most of the time we are
pushing less than full.
Except that any decent contactor controller will rewire the batteries
and/or motors in various series/parallel combinations to achieve speed
control. The resistors are out of the circuit for all speeds except
while starting from a dead stop. The resistors are only in the circuit
for a couple seconds, and only at very low voltages, so the power lost
in them is negligible.
Also, just getting up to full throttle is a problem, as it will be
less smooth, and we have more resistive losses to deal with the
higher inrush currents.
Dumping a motor to full on through a contactor causes more heating in
the batteries, cables, and motor windings. If you use a resistor to
soften the start, then that's obvious loss!
The inrush current is actually pretty small with a series motor. Were you
expecting it to be large?
A series motor behaves roughly like a resistor whose resistance is
proportional to rpm. For a 2:1 step in voltage, the current also makes a
2:1 step (because the apparent motor resistance is fixed). Its inductance
also delays and softens the rise and fall of current.
Suppose you want to drive at 40 mph, but your contactor controller has
only steps at 30 mph and 45 mph. Say 30 mph = 3000 rpm = 100 amps at 36v;
then your motor's equivalent resistance is 36v/120a = 0.3 ohms.
Now you step down to the next "click", and the voltage doubles to 72v.
Since rpm hasn't changed (yet), motor equivalent resistance also won't
changed; it's still 0.3 ohms. So motor current wants to go to I =
72v/0.3ohms = 240 amps.
Double the current means roughly double the torque; the car starts to
speed up. But as it does, motor rpm and thus motor equivalent resistance
also rise. So your speed won't double; it goes up perhaps 50% to 45 mph.
The weight of the car and the torque of the motor will make this take 5-10
seconds. That's a pretty gradual acceleration.
At 40 mph (your target speed), the motor is at 4000 rpm, so its resistance
has gone up to 0.4 ohms. The current is 72v / 0.4ohms = 180 amps. 45 mph
is 4500 rpm, 0.45 ohms, and 160 amps.
The same thing happens when you let up the pedal one "click" to slow back
down. It takes at least as long as it did to speed up, another 5-10
seconds. To maintain an average of 40 mph, you wind up cycling back and
forth between 36v and 72v with a 10-20 second cycle, with gradual speed
increases and decreases. A passenger may here the clicks, but probably
won't notice the speed changes or feel the torque pulsations.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Jerry,
You ask a lot and I cannot see what you are doing, but
I will insert some comments.
--- jerryd <[EMAIL PROTECTED]> wrote:
> While drawing it, I noticed how easy it
> would be to
> place a 6vdc battery in reverse voltage across the
> field to
> give regen and maybe reverse.
Simple reversal of the series field will not regen.
It will plug reverse. True, once you get a series
motor to regen, the series field needs to be reversed
physically, but the polarity will be the same as when
motoring, just that the current is going into the
battery now. So simply goosing the field backwards
with 6 volts will likely reverse the armature polarity
(Eg) and add to the battery voltage, drawing current
and producing a lot of reverse torque.
> Questions are how much voltage across the
> field
> should I use?
Depends on a lot of things. Load, motor design, etc.
Series motor field windings may be on the order of 10
milliOhms. So at 100 amp load, one volt.
> Should it be variable?
Not necessarily, if you can control things with the
armature controller.
> Can I use the batt for reverse too?
Probably, but realize that if your series motor has a
field resistance of 10 milliOhms, that 6 volt battery
is supplying 5 to 600 amps. You'll be saturated and
have a lot of heating in those field coils.
> Does the regular field wiring need to be
> removed by
> contactors to work or could you just add the batt
> accross it
> if enough voltage to overcome normal field voltage?
Hard to tell exactly what you have in mind. But it
will behave as any electric circuit. So if you have a
100 amps armature (and field) current and put a
reverse 6 volts across the field, seems to me like you
would get 500 amps reverse field current and the
original 100 amp armature current to start with. But
real quickly, the Eg will reverse and add to the
battery voltage causing a hugh spike in battery
current (and reverse torque). This spike in battery
current will oppose the current from the 6 volt
battery across the field and force it towards zero and
probably find an equalibrium or end up unstable.
Sounds interesting!!!!
> On other CC questions, can I S/P just the
> armatures
> on 2 motor setups and leave the fields together for
> easier,
Yes, this can be done. Here again, I do not know your
full intent. Say you leave the two motor fields in
series, then things are normal when your armatures are
in series, but when you switch the armatures in
parallel and leave the fields is series, you'll have
twice the normal field strength on each motor. This
will be "field strengthening". Motors will turn
slower, produce more torque, saturate sooner and heat
faster than when in the classical series motor
configuration and two of them in parallel.
> less contactors for reverse, maybe regen? I'm trying
> to
> avoid 2 sets of reverse contactors.
> Or just series/parallel the fields and
> reverse the
> armatures instead?
I don't see why not.
> Will an Altrax 7245 work without the field
> in
> series?
>
> Jerry Dycus
>
Obviously you know these PWM controllers use the
series field as the output inductor. Suitability for
armature only chopper depends on the particular
controller. I don't know about the Altrax. But it
can be done with other controllers. Any sepex or PM
controller does it with armature inductance only.
Hope this helps some.
Jeff
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--- End Message ---
