EV Digest 5309
Topics covered in this issue include:
1) Re: Motor options
by Electro Automotive <[EMAIL PROTECTED]>
2) Re: More or Less the Attitude of the Oil Companies, Comments
by "Joe Strubhar" <[EMAIL PROTECTED]>
3) Re: Motor options
by Lee Hart <[EMAIL PROTECTED]>
4) Re: Fast Street Car with Twin DC Motors
by Brian Cole <[EMAIL PROTECTED]>
5) Re: Best 8V battery and best place to purchase 18 of them
by John Norton <[EMAIL PROTECTED]>
6) Re: More or Less the Attitude of the Oil Companies, Comments
by Neon John <[EMAIL PROTECTED]>
7) Re: Conversions by those without metalshop experience
by David Dymaxion <[EMAIL PROTECTED]>
8) Re: DC-DC converter: How to select?
by Matt Milliron <[EMAIL PROTECTED]>
9) Re: DC-DC converter: How to select?
by <[EMAIL PROTECTED]>
10) Re: I need to rephrase my "motor options" question
by Jeff Shanab <[EMAIL PROTECTED]>
11) Re: Conversions by those without metalshop experience
by <[EMAIL PROTECTED]>
12) Motor Field Weakening for higher RPMs
by Jeff Shanab <[EMAIL PROTECTED]>
13) "new" EV survey
by Seth Rothenberg <[EMAIL PROTECTED]>
14) Re: DC Motors for Racing (and Matt's Nissan 200SX)
by "Ryan Stotts" <[EMAIL PROTECTED]>
15) Re: Fast Street Car with Twin DC Motors
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Motor Field Weakening for higher RPMs
by James Massey <[EMAIL PROTECTED]>
17) Re: Motor Field Weakening for higher RPMs
by Joel Hacker <[EMAIL PROTECTED]>
18) Anyone from FVEAA going to the Midwest AFV Expo???
by Joel Hacker <[EMAIL PROTECTED]>
19) Re: More or Less the Attitude of the Oil Companies, Comments
by "Michaela Merz" <[EMAIL PROTECTED]>
20) Re: "new" EV survey
by Lee Hart <[EMAIL PROTECTED]>
21) Re: More or Less the Attitude of the Oil Companies, Comments
by Neon John <[EMAIL PROTECTED]>
22) Re: "new" EV survey
by "David Roden" <[EMAIL PROTECTED]>
23) Re: automatic battery watering
by "David Roden" <[EMAIL PROTECTED]>
24) RE: Motor Field Weakening for higher RPMs
by "rcboyd" <[EMAIL PROTECTED]>
25) Re: More or Less the Attitude of the Oil Companies, Comments
by "David Roden" <[EMAIL PROTECTED]>
26) Re: More or Less the Attitude of the Oil Companies, Comments
by Lee Hart <[EMAIL PROTECTED]>
--- Begin Message ---
Well first I state that everything or at least most of what I
post is in "my opinion". Now I've seen and worked with enough
people to know that most systems are 120 volt and even at that most
feel the performance is below what they would want.
Maybe most of the people YOU know. Most of the ones I talk to are
quite happy with the performance. We obviously hang in different
crowds. That's my point.
I did a shaft job for Howard down in Cali who did a 36 / 48 volt
7" Prestolte in a rabbit and it did 60 mph.
Whoa! You said "most people". Are "most people" using 36/48V
Prestos? I don't think so. Most that I know are using 8" or 9"
ADCs, or WarPs or ImPulses, or even Kostovs. The original post to
which you were responding was talking about a 9" ADC motor. To run
THESE motors at "2x - 3x" their rated voltage would be 300V -
400V. Are "most people" running this? Again, I don't think so.
So these are the basis of why I'd say up the voltage rather than
undersize the battery pack.
I have no argument with that. I would also increase the battery
pack. My disagreement was with "most people" and "2x - 3x rated voltage."
We don't recommend less than 96V for a very basic street car, nor
do we recommend above 144V on the 9" motor.
I've run Blue Meanie's 'properly advance timed' ADC 9 inch motor at
156V for I think, 10 years now. Not a single motor problem, and the
original brushes are at around 75% still. Many others, like John
Bryan and his 192V Ghia with its XP super torque'n 8 inch ADC motor,
have also not had any problems at all....nor has Bill Dube's 192V
Wabbit...this list could go on and on.
Your privilege. But I sell these and have to warranty them. I want
the factory backing me up.
I have this funny idea of knowing the manufacturer (ADC) isn't smart
enough to advance the timing to 10-12 degrees so that their motors
will run properly for the market they sell them for...EVs.
I would love to see you tell Gary Dieroff to his face that he isn't
smart enough to build a motor properly.
Way back in the dark ages, we used Prestolites because they were the
best choice we had. Then Gary Dieroff and Bill Rodgers of ADC came
to us and said, "We want to build motors for conversions. What do
you need? Here's one of our motors, give it a try, then tell us what
we need to change." Then they proceeded to change the motor design
specifically to be used in EV conversions.
Can you say Corbin Sparrow?
That's Corbin's problem, not ADCs. The Sparrow had problems with
several drive systems.
I also have this funny idea of running an EV's motor at higher
voltages for far less average current to keep the motor running
cooler, the com. and brushes lasting far longer, and for making
power on order with what the gas version originally had (or even more).
I would suggest that running these motors at between 96V and 120V is
probably way harder on them, than at higher voltages,
However, we have been doing exactly that with these motors since they
came out. The only failures we have had were from people who
over-revved them, either coasting downhill or towing in too low a
gear. Some of these cars have been happily in service for 10 or 15 yearrs.
Add in the fact that most of the Electro Automotive designs
feature very heavy conversions with lower than average power, and
you are asking the motor to work under even more duress. Most of
the Electro Automotive designs use the squealing Curtis controller
Here we go again. I've never heard the Curtis squeal except backing
out of a parking space, when it serves nicely as a pedestrian
warning. In forward motion, I accelerate through that low speed
squeal too quickly to notice it. (Yes, even in my pitiful low
voltage, low current car, I can accelerate that quickly!)
only capable of 500 amps. On a 96V Rabbit, a small car that
unfortunately weighs in at over 3000 converted lbs.,
Try 2880 lbs.
considering 6V wet cell voltage sag under 500 amp draws, there's
only 40 kw of max power, or just 40 delivered hp to move 3000 lbs.
of mass....argh! Talk about a prescription for low performance and
an overheating motor!
We ran one of these "pitiful" Voltsrabbits at Phoenix, at highway
speed, for 2 hours in 110 F ambient. No overheating. Did the same
thing in a Voltsporsche at Phoenix. We have NEVER had a motor
returned for overheating issues. And as for low performance, I have
more often been held back in a 96V Rabbit by slow gas cars than vice
verse. I have even passed gas cars going uphill. And the poor ADC
9"/Curtis 20x6V Voltsporsche? 90+mph. Yeah, pretty sad and inadequate.
Rant:
There are a lot of different kinds of people who drive EVs. Sweeping
generalizations about "most people" are usually misleading. This
means "most people you hang out with", which is generally a
like-minded group, a subset of the EV universe, not the whole.
Some people on this list are into dollars-be-damned
acceleration. Others just love to constantly measure and analyze and
tinker and tweak. Some have more monitors on their cars than on
patients in the ICU. That's fine, if that floats your boat. Just
realize that there are a LOT of other types of people, too. For an
extreme example, there are people (some on this list) who
passionately adore their Sebring Citicar. Talk about low
performance! But it meets their needs. My customers are very happy
with their ADC/Curtis conversions overall. The words I hear
repeatedly are "love it", "peppy", "fun to drive".
If we could refrain from calling other people's well-loved
conversions "dogs", "slugs", "underpowered", and similar slurs and
recognize that satisfactory performance is very subjective, then I
will continue to refrain (as I have until this moment) from comments
about testosterone poisoning and cars as penile prosthetics.
End Rant
Shari Prange
Electro Automotive POB 1113 Felton CA 95018-1113 Telephone 831-429-1989
http://www.electroauto.com [EMAIL PROTECTED]
Electric Car Conversion Kits * Components * Books * Videos * Since 1979
--- End Message ---
--- Begin Message ---
OK, guys - enough of this OT crap! Take it off-list, please! Not all of us
accept your theories and political philosophy!
Joseph H. Strubhar
E-Mail: [EMAIL PROTECTED]
Web: www.gremcoinc.com
----- Original Message -----
From: "Bob Rice" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, April 02, 2006 9:16 AM
Subject: Re: More or Less the Attitude of the Oil Companies, Comments
>
> ----- Original Message -----
> From: "Peter VanDerWal" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Sunday, April 02, 2006 9:10 AM
> Subject: Re: More or Less the Attitude of the Oil Companies
>
>
> > Perhaps, perhaps not. I've actually seen some interesting commercials
on
> > satellite tv over here in the Middle East.
> > Hi EVerybody;
>
> > One stated "In the world wide search for oil, slightly over two barrels
> > are consumed for every barrel discovered"
>
> > Hmmmm, a message here somewhere?
>
> > Another claimed that some large percentage of the worlds oil (can't
> > remember exactly, but way over 1/2) comes from just five countries, then
> > it finishes by asking "what country do you live in?"
>
> Why is this important?
>
> >
> > Both commercials were sponsored by Cheveron Oil.
> > I have seen the Cjhevron ads, too. But they don't mention the danage
the
> FOUND oil is doing for the Planet. Just the quest for MORE, to help their
> bottom line. Hell, If they would just sell off their battery patent rights
> to the Panasonic battery.An Icebreaker made it to the North Pole,
recently.
> Carnaval cruises will be able to sail the "Soverighn of the Artic" liner
> there without an icebreaker, in a few years.And my inland Killingworth CT
> property will be valuable Waterfront<g>!
> >
> > > All the more reason for EV's (as though more reasons were necessary).
> > > Amen!
> > >
> 60% outside today, nice global warming!
>
> Bob
>
>
--- End Message ---
--- Begin Message ---
Electro Automotive wrote:
> ...ADCs, or WarPs or ImPulses, or even Kostovs. The original post to
> which you were responding was talking about a 9" ADC motor. To run
> THESE motors at "2x - 3x" their rated voltage would be 300V-400V.
> Are "most people" running this?
I think there are two reasons for the difference of opinions here.
First, Shari and Jim are talking about two different groups -- economy
EVs vs. high-performance EVs.
Second, a PWM controller steps the pack voltage down, so the motor
voltage is (almost) always less than the pack voltage. In an EV with a
96v pack, the motor will often be at the fully pack voltage. But in an
EV with (say) a 200v pack, the motor will *still* be at 96v or less most
of the time.
--
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 ---
> > Date: Sun, 02 Apr 2006 14:00:18 -0500
> From: Lee Hart <[EMAIL PROTECTED]>
> To: [email protected]
> Subject: Re: Fast Street Car with Twin DC Motors
>
> Rich Rudman wrote:
> > What makes sense is copper cables... and massive
> aluminum buss bars.
>
> Maybe; it depends on the situation. It's easier to
> make connections
> between the same metals. Connecting copper to
> aluminum requires special
> techniques and skill. I'd be tempted to get my
> aluminum buss bars copper
> plated, to simplify the connection difficulties.
> And, I'd minimize the
> number of connections, and weld as many of them as
> possible, to
> eliminate problems.
How about using a copper-clad aluminum wire like
Copperweld's? I believe it comes aa bare wire.
http://www.copperweld.com/cwwire/cladalum.html
-brian
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
On Sun, 2 Apr 2006 18:45, Adams, Lynn wrote:
Well my experience:
US8VGC 12000 miles
US8VGC-HC 14,000 miles but more acid leak
Trojan T875 16,000 miles
Trojan T890 Sold car at 14,000, expect I would have gotten at least 18K
Battery cost per mile, about the same across the board.
I would recommend either the US8VGC or the Trojans, depending on price.
Keep the batteries warm in the winter and cool in the summer will help.
You can have the US batteries shipped right to your door, a nice
feature
(and still costs less than the Trojans)_
Also researching as I begin the ev road - what about Exide gc110's in
8v? Kingsolar has them @ $79.
What prices are available on the Trojans and USB?
John F. Norton
via T-Mobile Sidekick
--- End Message ---
--- Begin Message ---
On Sun, 2 Apr 2006 12:16:47 -0400, "Bob Rice" <[EMAIL PROTECTED]>
wrote:
<buncha crap>
How 'bout taking this political crap somewhere where it belongs?
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
--- End Message ---
--- Begin Message ---
My humble opinion: If you are doing just one (or even a small number)
of conversions, it is much faster and cheaper to buy stuff like
adapters or farm out fabrication and welding.
For myself, I bought a lathe/mill and welder, and having been
teaching myself these skills. The tools cost alot, and learning to
use them has been time consuming. I'd probably be done by now had I
not done that. However, big but here, there is a massive intangible
benefit: Fun and learning! I have really enjoyed learning about and
acquiring these new skills.
The other comment is you would need to do accurate and strong work
(good to a couple 1/1000 of an inch in some cases). A weld breaking
or an off-center adapter can cause alot of grief.
--- Joel Hacker <[EMAIL PROTECTED]> wrote:
> I heard a while back on this list that one of
> the most helpful skills in doing a conversion
> was to have metalshop experience, but it is
> unfortunate that most of those doing their own
> conversions are more of an EE/physics background
> and did not gain the metalshop experience.
>
> I fall into that category, and as I dream about
> my future conversion opportunities, I am really
> worried as to how one goes around this hurdle.
>
> Does one take a welding class? Does one make
> friends with the local body shop owner? Does
> one get auto-cad out and hunker down and pay
> the body shop to do all the work for him?
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
On Sun, 2 Apr 2006 17:48:25 -0700 (PDT), you wrote:
>Wow, this guy has almost 1,000 negative feedbacks _in
>the past month!_
>
I am only in for 99 cents so far. I will chance it.
Matt Milliron [EMAIL PROTECTED]
1981 Jet Electrica, Ford Escort
My daughter named it, "Pikachu".
It's yellow and black, electric and
contains Japanese parts, so I went with it.
http://evalbum.com/702.html
--- End Message ---
--- Begin Message ---
Be aware that the Curtis 1400 doesn't span the 24-96 volt range all in one
unit. The common one I have seen on ebay is 24-36 volt input. I couldn't
tell from this description what the input rating is and the part number
doesn't come up in a search of the Curtis site.
OTH, I have a 1400 installed on my electric servi and it is working happily
at 24V input during my testing.
respectfully,
John
58 electric servi-car in progress
----- Original Message -----
From: "Matt Milliron" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, April 02, 2006 7:24 PM
Subject: Re: DC-DC converter: How to select?
On Sun, 2 Apr 2006 17:48:25 -0700 (PDT), you wrote:
Wow, this guy has almost 1,000 negative feedbacks _in
the past month!_
I am only in for 99 cents so far. I will chance it.
Matt Milliron [EMAIL PROTECTED]
1981 Jet Electrica, Ford Escort
My daughter named it, "Pikachu".
It's yellow and black, electric and
contains Japanese parts, so I went with it.
http://evalbum.com/702.html
--- End Message ---
--- Begin Message ---
Ok, here is a potential soulution for low voltage low current operation.
Dual motors and the tranny.
Perhaps a contactor could be tied to a button on the stick shift.
put the vehicle in first, hold down the switch and press the accelerator
get to a speed 1/2 way to second gear and release the switch, then shift
to second normally and hold in the switch again for series mode in 2nd gear
holding it half way to third and then release. and so on.
--- End Message ---
--- Begin Message ---
Asking here is a good first start.
See if there are any others on the list in your area or check out a local EV
group.
You might even try the local hotrod club. At least around here they meet
during the warmer months every week or every other week at a local diner.
What you are doing is usually interesting to them as well and they may have
lots of the skills you are looking for.
The junior college is also a good idea as suggested before. I inherited a
lathe and finally took a basic machine shop class at the local JC and it
really helped. They are also a source to locate the equipment if you are in
the market. Our local instructor was also very good about letting students
work on their own projects instead of the "class assignment"
If you are in the far northern California area, I am willing to help too.
see http://www.indele.com/page6.html to see some of what I can do.
respectfully,
John
58 electric servi-car in progress
----- Original Message -----
From: "Joel Hacker" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, April 02, 2006 4:21 PM
Subject: Conversions by those without metalshop experience
I heard a while back on this list that one of
the most helpful skills in doing a conversion
was to have metalshop experience, but it is
unfortunate that most of those doing their own
conversions are more of an EE/physics background
and did not gain the metalshop experience.
I fall into that category, and as I dream about
my future conversion opportunities, I am really
worried as to how one goes around this hurdle.
Does one take a welding class? Does one make
friends with the local body shop owner? Does
one get auto-cad out and hunker down and pay
the body shop to do all the work for him?
Just scratchin' my head here.
Thanks,
Joel
--- End Message ---
--- Begin Message ---
I'll take a stab at it.
Every motor is a generator, simultaniously. The difference at any time
between the applied voltage and the generated voltage (Back EMF) is
available to push current thru the windings and generate torque. It is
why the torque diminishes as RPM's climb.
At high rpms the voltage generated is too high and is blocking the
current flow in the armature, reduce this voltage and some current will
flow giving you some more torque. At zero rpm it would only detract from
the motors output since there is no BEMF yet.
--- End Message ---
--- Begin Message ---
(long, rambling. Proposed plan in last page :-)
I knew that my colleague's husband had bought
a battery charger, because he didn't know (then)
how to turn around a car with a dead battery
(electronic transmission lock)....so I borrowed it...
...and I charged the accessory battery,
and tested parts I know I need and I don't
want to mess with...and!
Lights flashing, wipers going, horns honking -
NOT! the horn needs to be checked, but
other things work, (need one yellow bulb,
and one brake bulb :-)
So, I went back to the family, "bonding",
cleaning for Passover. "Honey, would you clean
the cars?" Oh, I better clean the new Saturn too...
(ha, I don't think anyone ever ate in it :-)...
vacuumed out the glass, leaves...and connected the
charger to the first traction battery...
by sunset, it read 12.01 volts.
Jumper cables, indispensible...the Kostov turns.
I don't know for sure if everything (bearings) is in perfect shape,
but it turned easily on a nearly-dead 12V battery.
(car in neutral, I made sure not to win a Darwin Award :-)
All Cable is nice 2/0.
Interesting, it turns the same way with voltage reversed.
Must be that jumper on the side.
So, I need:
One brake bulb, One front signal bulb, Dome lamp assembly, Wiper fluid
Horn diagnosis - probably cut wire in the "motor room" of all places
Controller + Potentiometer
DC/DC
Batteries
Vacuum pump for brakes
Possibly some contactors
Meters Meters Meters
So, my thought is this...
The LAST thing I need is the Batteries, the FIRST thing
I need to decide is the batteries...basically, choose
a form factor and battery count, build EVerything around it,
then order batteries last...hopefully, we're talking just
a few months' difference anyway.
There are steps to calculating lead capacity of the car,
but I can think about the controller at the same time.
So, just like someone asked the other day about batteries,
I'll ask about controllers. Is there a comparison of
EV Controllers? Or is that another job for Jerry and Mike
(and any data-mining help I can offer)?
I'll be looking for about 132-144 volt DC controller, for a Kostov,
and to be able to push it (given <4000 lb GVW )
(I probably would rarely push it, but for the "sales" pitches...)
I would love to know if there is a controller with integrated
Cruise Control? (Am I right, it makes sense to do this digitally
rather than the old fashioned way?)
As for DC/DC, some mention was made about using a switching power supply...
has anyone had a positive experience with them? (The upside
of that, is I have a basement that's overflowing :-)
As for vacuum, what kind of rating do people look for....
and, is a compressor rated the same way, such that
one could shop for a compressor - some have done this, right?
BTW, about the batteries...It's sounding like Hawkers are
the bang-for-buck leader. I don't live near anything EV-ish,
but I Do drive almost through "the City" every day...
what's the easiest way to plan the battery order?
There's a NAPA near here, didn't seem to be much of a store.
There's also a West Marine, which DOES seem like a good store.
There's also an EV supplier (mainly golf carts) near my work.
(BTW, it looks like Hawker's parent is in nearby PA?)
Thanks for everyone's advice!
Seth
--- End Message ---
--- Begin Message ---
Rich wrote:
> 350 volts on a commutated motor... is a LOT. Well at least for these
> small over grown fork truck motors we call EV motors.
So Dennis, care to share how to run more then 170 volts to one of these motors?
--- End Message ---
--- Begin Message ---
Brian Cole wrote:
> How about using a copper-clad aluminum wire like
> Copperweld's? I believe it comes aa bare wire.
> http://www.copperweld.com/cwwire/cladalum.html
Yes, this will be a lot easier to connect. Be aware, however, that
aluminum is still softer, and expands more with temperature than copper.
You can't just wrap an aluminum wire around a plain old screw, tighten
it down, and expect it to *stay* tight. As the temperature rises, the
aluminum expands so much that its is crushed by the screw. Then when the
connection cools, the aluminum shrinks. Now you have a loose connection.
It causes further heating on the next cycle, further crushing when hot
and shrinkage when it cools etc. until the connection fails.
The trick is to use special connectors meant for aluminum. They either
expand and contract at the same rate, or have spring pressure clips to
maintain controlled pressure despite expansion and contraction with
temperature.
--
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 ---
At 05:43 PM 2/04/06 -0500, Joel wrote:
Would someone few minutes and explain why you
have to weaken the field strength of a high-torque
motor to get higher RPMs?
Hi Joel, and all
OK, I'll have a shot at this, and try and explain it in plain enough
language wwithout getting away from motor words (so some statements may not
be entirely correct, just 'near enough' so please don't shoot me for it).
I'll describe this following the example of a shunt motor, compared to a
series motor - the theory follows the same for a series motor, but the
dynamics are all over the place as the field current is the armature
current in a series motor.
OK, power up the field of our hyopthetical motor, this gives a certain
magnetic strength. In a wound motor this is talked of as Amp-turns
(Ampere-turns) which is amps x the number of turns. A shunt motor may have
500 turns at 5 amps, and gives the same amp-turns (2500 Amp-turns) as a
series motor with 10 turns at 250A. A permanent magnet motor has a fixed
strength so doesn't come into this.
Now, our motor with a certain armature voltage applied wants to run at a
given speed in this magnetic field (a *perfect* motor with no losses would
be at this speed), if you spin the motor faster (by an external means) it
will generate power (dynamic or regenerative braking), and if you load it
down to a slower speed it draws current to try and get up to this speed
(acceleration).
The lower the amp-turns, the higher this steady-state speed is, so lowering
the field amps increases the speed of this steady state. In a series motor,
the amps are falling as the RPMs go up, so the RPMs want to go up further,
which is why a series motor will try and rev itself to death. But, as the
amps fall, the power being delivered falls as well, and so the car reaches
a steady state, balancing the loaded speed of the motor against the windage
of the car at speed.
With a shunt (sepex) motor the field is varied to vary the speed that the
motor wants to run at when the full battery supply is on the armature.
So now we reduce the field strength of the series motor by bypassing some
of the field amps, so our amp-turns falls. The 'steady-state' speed of the
motor is now faster, so the motor draws more current and can now deliver
more power. The trade-off is that at lower amp-turns the torque is lower.
OK, now the torque comes into it - off the line, at low RPMs, we want as
much torque as possible, so the highest amp-turns possible. Torque becomes
horsepower when you multiply it by RPMs, so as the RPMs climb, so does the
horsepower. Once the car starts to 'flatten off' there are lots of RPMs, so
the torque number can be lower and still deliver horsepower. So as we
weaken the amp-turns, and the possible torque value, we make the motor draw
more current, and so deliver more horsepower than if the field wasn't weakened.
Hope this doesn't confuse too much.
Regards
James
--- End Message ---
--- Begin Message ---
okay...that makes sense...then how do you reduce the voltage
(I assumed to the field windings) without lowering your RPM's?
Does this take tachometer feedback into the controller and
the controller slowly backs off the voltage while still monitoring
the RPM's???
Jeff Shanab wrote:
I'll take a stab at it.
Every motor is a generator, simultaniously. The difference at any time
between the applied voltage and the generated voltage (Back EMF) is
available to push current thru the windings and generate torque. It is
why the torque diminishes as RPM's climb.
At high rpms the voltage generated is too high and is blocking the
current flow in the armature, reduce this voltage and some current will
flow giving you some more torque. At zero rpm it would only detract from
the motors output since there is no BEMF yet.
--- End Message ---
--- Begin Message ---
I don't know if there is a mailing list for the FVEAA
(Fox Valley, Illinois), but I am interested in going
down to the Midwest AFV Expo and wondered if anyone
else was going to I could hop a ride with, meet some
new friends, and split the gas money with to see the
event.
--- End Message ---
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Hello :
I've got a problem. Well, we all have. We know what is happening to our
planet and we will be held accountable by our kids. Problem is: Nobody
does anything about it. Well, we drive our EVs (that's a start), we talk
about it here and other places, gosh, we might even donate money to
Greenpeace et al. But we kind of know, that nothing's going to change
without something BIG happening. And it frustrates me. Because I am not
putting my money where my mouth is. I got family to take care of, my house
payments, two jobs, well, that sort of things. While I seriously hope
somebody is going to do something, I aint got time. Sorry. (End of excuses
:)
The other day, I was talking to somebody and we were discussing if we
should follow the big cigarette law suits and just sue, say, Exxon for
knowingly destroying the health and welfare of its customers.
It went like this:
Him: Heck - this that might be a good idea.
Me: Even if we lose, we sure would get some attention.
Him: It might force them to come up with different technologies.
Me: Yeah .. they've got the money to come up with something ..
Him: The sure got money.
Me: Hmm .. what do you think?
Him: Well, would sure be a great idea.
Me: Yes.
Him: I am sure it'll happen some time.
And so on. But the sad thruth is, that nothing will happen unless somebody
makes it happen. And I feel sad that I don't have the guts to stand up and
say: It's enough. Because I may end up in some place I don't like.
I better start working on some kind of story I will tell my grandkids.
Sort of the story my (German) grandfather told me whenever I asked him
what he did about the Nazis. But my story will be better. I knew what was
coming for a much longer time.
Michaela
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Welcome, Seth. Sounds like you're off to a good start. The fun has
begun...
Seth Rothenberg wrote:
> and connected the charger to the first traction battery...
> by sunset, it read 12.01 volts.
Ok, that's progress. Is that the voltage *while* charging at some
current, or the voltage *just after* disconnecting the charger, or after
some period of time with the battery sitting idle? Hopefully the latter;
the other two cases mean that battery is looking pretty grim.
> Jumper cables, indispensible...the Kostov turns.
Excellent!
> So, my thought is this... The LAST thing I need is the Batteries,
> the FIRST thing I need to decide is the batteries... basically,
> choose a form factor and battery count, build EVerything around it,
> then order batteries last...
Sound logic. What batteries are in it now? It would be easier to stay
with something the same size, unless you want to rebuild the battery
boxes.
> Is there a comparison of EV Controllers?
Sure; there's lots of data on the many different choices.
New PWM: Alltrax (low voltage), Curtis (medium voltage), Zilla (high
voltage).
Used PWM: Many brands can be found; all the above, plus Auburn, DCP, GE,
PMC, Russco, Sevcon, Zapi, and more (alphabetically). Find one
suitable for your pack voltage and motor current.
Contactor controller: Simple and crude. Easy to build; not normally a
purchased item.
> I would love to know if there is a controller with integrated
> Cruise Control?
None I know of.
> As for DC/DC, some mention was made about using a switching power
> supply... has anyone had a positive experience with them? (I have a
> basement that's overflowing :-)
Your pack voltage (132-144vdc) is at the lower edge of where you can use
a stock AC-input switcher; 120vac is equivalent to 168vdc, and you're
well below that. If your basement bargains are cheaply made PC power
supplies, I wouldn't bother. If they are quality industrial supplies
that have both AC and DC input voltage ratings, then you have a better
chance to make one work. Look for one that you can adjust the output to
about 13.5 volts.
> As for vacuum, what kind of rating do people look for...
You don't need much. A vacuum pump that runs on 12vdc at 5-10 amps is
powerful enough.
> BTW, about the batteries...It's sounding like Hawkers are the
> bang-for-buck leader.
They are very expensive, but deliver very high peak power. Good for fast
EVs or racing. Not good for an economy car.
> There's also an EV supplier (mainly golf carts) near my work.
You might ask them if they sell used batteries. Many golf courses
blindly replace their batteries every X years, needed or not. These can
be cheap source of "training wheel" batteries.
--
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
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On Sun, 2 Apr 2006 22:43:51 -0500 (CDT), "Michaela Merz"
<[EMAIL PROTECTED]> wrote:
>
>Hello :
>
>I've got a problem. Well, we all have. We know what is happening to our
>planet and we will be held accountable by our kids. Problem is: Nobody
>does anything about it.
"WE" don't know anything of the sort. Some of you lunatic fringe
eco-whackos delusionally think you "know" but you don't. It has
become a secular religion of sorts, where you believe stuff based on
nothing other than faith and because someone else said it was so. To
the rest of us, you're comical. Sadly comical, I might add.
This so much reminds me of the old Marine Corps saying, "If I'd wanted
your opinion, I'd have beaten it out of you." And, of course, "Better
to remain silent and be thought a fool than to speak up and remove all
doubt."
This list is about EVs and not about eco-nazi spew. Take it wherever
there is someone who GAS! If that place exists.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
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On 2 Apr 2006 at 22:48, Seth Rothenberg wrote:
> I would love to know if there is a controller with integrated
> Cruise Control?
Brusa inverters for AC induction motors (from at least the AMC-320 range and
I think the earlier AMC-300) have a built in "tempomat" which provides a
cruise function.
I don't really see much value to cruise in an EV, since most EVs carry only
enough energy to run for an hour at most. Very few of us drive our EVs on
long trips, which is when cruise matters. But I guess some folks might
still appreciate it on shorter trips.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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On 2 Apr 2006 at 10:42, elaine chiu wrote:
> also, is there a place to get a suitable float valve that would
> work?
Here's a drawing that shows THE automatic watering caps used on Saft nicad
monoblocks with removeable cell caps :
http://www.tokki.org/ev/images/saft_wtr.jpg
These have no moving parts, which improves reliability. Saft explains the
operation this way :
"The concept is to fill a cell with water up to a specified level allowing
gas which is in the cell to escape. When the specified level is reached, the
electrolyte closes the gas exhaust tube and the consequent excess pressure
stops the water flow into the cell. The water will now flow to the next cell
and so on, to the last cell of the hydraulic circuit.
"Each vent cap has a tubular body (1) fitted with a water inlet (2) and
outlet (3) in its upper part, and with a gas exhaust tube (4) in its lower
part. The water flows across the vent because of a plunging siphon (5) and
then flows into the cell through a water hole (6), while the gas escapes
through the exhaust tube (4).
"The lower edge of the gas exhaust tube (4) determines the electrolyte level
of the cell. During the watering process, when the electrolyte reaches this
level, the air under the cover can no longer escape through the gas exhaust
tube (4), and the water reserve generated by the plunging siphon ensures a
safe obstruction of the gas inside the cell. The water filling of the cell
is over, and the water flows to the next cell through the outlet (3).
"In order for the system to work correctly, the water flow must be lower
than 0.7 liter per minute and the relative internal pressure below 0.15
bars."
I don't think Saft makes these for retrofit applications, but surely someone
else uses a similar principle.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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You parallel the field with a length of wire and a push button connecter
to keep it on for the part of the run where you need higher RPM
Bob Boyd
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Joel Hacker
Sent: Sunday, April 02, 2006 8:34 PM
To: [email protected]
Subject: Re: Motor Field Weakening for higher RPMs
okay...that makes sense...then how do you reduce the voltage
(I assumed to the field windings) without lowering your RPM's?
Does this take tachometer feedback into the controller and
the controller slowly backs off the voltage while still monitoring
the RPM's???
Jeff Shanab wrote:
> I'll take a stab at it.
>
> Every motor is a generator, simultaniously. The difference at any time
> between the applied voltage and the generated voltage (Back EMF) is
> available to push current thru the windings and generate torque. It is
> why the torque diminishes as RPM's climb.
>
> At high rpms the voltage generated is too high and is blocking the
> current flow in the armature, reduce this voltage and some current
will
> flow giving you some more torque. At zero rpm it would only detract
from
> the motors output since there is no BEMF yet.
>
>
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Please don't originate or continue threads that are primarily political in
nature on the EV list. This is well-trod ground offlist for nearly everyone
here and need not be discussed - indeed it is not a good use of list
bandwidth.
To put it another way, you can flame until we're all crispy critters, but
nobody will change his or her mind. Don't waste your time and list
bandwidth.
Remember that an interest in EVs is what we have in common. The REASONS for
that interest are widely varied and have "hot buttons" all over them.
Pushing those buttons makes more heat than light. So don't.
If you want to argue, better you should confine yourself to such more on-
topic and less volatile controversies as flooded vs. AGM, AC vs. DC, and
perhaps even economy commuter vs. high performance tireburner.
Thanks.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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Michaela Merz wrote:
> I've got a problem. Well, we all have. We know what is happening to
> our planet and we will be held accountable by our kids. Problem is:
> Nobody does anything about it.
It's human nature to not do anything about a problem, in the hopes that
it will go away by itself, or that someone else will solve it for you.
> The other day, I was talking to somebody and we were discussing if we
> should follow the big cigarette law suits and just sue, say, Exxon for
> knowingly destroying the health and welfare of its customers.
That seems like another way to avoid the problem, by making it someone
else's fault. I can't see that destroying (say) Exxon would accomplish
anything; it's place would just be filled by other oil companies.
> But the sad truth is, that nothing will happen unless somebody
> makes it happen.
True enough. And that is what gives me hope. People *are* making things
happen. You, and everyone else reading the EV list! We are discussing
the problems, studying and experimenting with solutions, and educating
people on what options may be available.
It's a small thing at this point; but all large things started small.
--
Never doubt that a small group of thoughtful people could change the
world. Indeed, it's the only thing that ever has! -- Margaret Mead
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
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