EV Digest 6777
Topics covered in this issue include:
1) Re: Permanent magnet motor question
by "George Swartz" <[EMAIL PROTECTED]>
2) Re: Using Audio Capacitors for Dragsters
by Bill Dube <[EMAIL PROTECTED]>
3) Re: Permanent magnet motor question
by "George Swartz" <[EMAIL PROTECTED]>
4) Solectra/Azure Dynamics DMOC445 AC controller
by Tehben Dean <[EMAIL PROTECTED]>
5) Re: Using Audio Capacitors for Dragsters
by "Marty Hewes" <[EMAIL PROTECTED]>
6) Re: Using Audio Capacitors for Dragsters
by Jack Murray <[EMAIL PROTECTED]>
7) Re: Electric Power Steering
by [EMAIL PROTECTED]
8) Re: Using Audio Capacitors for Dragsters
by Steven Ciciora <[EMAIL PROTECTED]>
9) Re: Permanent magnet motor question
by [EMAIL PROTECTED]
10) Re: Using Audio Capacitors for Dragsters
by Bill Dube <[EMAIL PROTECTED]>
11) Re: Vehicle efficiency, wh/mile
by "Al" <[EMAIL PROTECTED]>
12) Re: Permanent magnet motor question
by "George Swartz" <[EMAIL PROTECTED]>
13) Re: Vehicle efficiency, wh/mile
by Ralph Merwin <[EMAIL PROTECTED]>
14) Re: Using Audio Capacitors for Dragsters
by Bill Dube <[EMAIL PROTECTED]>
15) Re: Charging timer
by Ralph Merwin <[EMAIL PROTECTED]>
16) RE: Solectra/Azure Dynamics DMOC445 AC controller
by "damon henry" <[EMAIL PROTECTED]>
17) Re: Using Audio Capacitors for Dragsters
by "Ryan Stotts" <[EMAIL PROTECTED]>
18) Re: Vehicle efficiency, wh/mile
by "George Swartz" <[EMAIL PROTECTED]>
19) Re: Solectra/Azure Dynamics DMOC445 AC controller
by Tehben Dean <[EMAIL PROTECTED]>
20) Permanent magnet motor question
by Jeff Shanab <[EMAIL PROTECTED]>
21) Drag Racing tech. Comments WAS Re: Using Audio Capacitors for Dragsters
by "Bob Rice" <[EMAIL PROTECTED]>
22) Re: Solar boat completes Atlantic crossing - Green Machines -
MSNBC.com
by "Bob Rice" <[EMAIL PROTECTED]>
23) belly pan plastic
by "Al" <[EMAIL PROTECTED]>
24) Re: Vehicle efficiency, wh/mile
by [EMAIL PROTECTED]
25) Zivan DC/DC
by "Al" <[EMAIL PROTECTED]>
26) Re: Vehicle efficiency, wh/mile
by "George Swartz" <[EMAIL PROTECTED]>
27) Re: Solectra/Azure Dynamics DMOC445 AC controller
by "damon henry" <[EMAIL PROTECTED]>
--- Begin Message ---
A permanent magnet DC motor is just like a shunt motor with a fixed field.
It is not as well matched to traction as a series motor and it is not as
versatile as a separately excited motor.
The permanent magnet motor tries to run at a constant speed proportional to
armature voltage. You cannot field weaken, and it will not run above base
speed. It does have an efficiency benefit since the field is not powered,
but overall efficiency in a traction application may or may not be as good
as a wound field motor.
On Tue, 15 May 2007 16:55:22 -0700 (PDT), Frank John wrote
> Can someone explain if there's any functional difference with a PM
> motor (compared with a DC series motor) from a user's standpoint? I
> see angular-velocity and torque constants listed but
> don't know if I understand how these are manifested in an
> application. Is RPM limited and will the motor try to achieve that
> speed even under load? I like the light weight and the potential
> for regen appeals to me for another m-cycle project I'm thinking about.
>
> TIA for explanations on how these things work.
>
>
_____________________________________________________________________________
_______
> Get your own web address.
> Have a HUGE year through Yahoo! Small Business.
> http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
--- End Message ---
--- Begin Message ---
A transmission has weight and the parts spin. These things slow you
down on the drag strip.
Again, just do a few basic calculations. You will discover that caps
just can't provide the watt-hrs/kg that you need to get to the end of
the drag strip. Batteries out-perform caps in both specific power and
specific energy.
Indeed, it is best if you can stay at the traction limit at the
beginning and not worry so much about later on. Easier said than done, however.
Bill Dube'
At 04:58 PM 5/15/2007, you wrote:
Well, if you had unlimited energy in zero weight batteries, then
you'd want to stay right on the brink of breaking loose the whole
way. In practice, I think it would require a continuously variable
transmission to keep the RPM under control to get anywhere close to
that point. But is there such a thing as a battery pack that can
dump that much wattage anyway? Certainly caps alone would be
dropping their voltage much faster than the equivelent voltage in
batteries, since there is no flat spot in the discharge curve, so
you'd have to be actually pulling the RPM down with reduced gear
reduction as the cap voltage dropped? Either that or you need a
trick controller/inverter that can put out more voltage than it sees
from the caps, which I believe is the equivelent of an electrical CVT.
I think if the available energy is limited, you want to expend it as
early as possible within the bounds of traction. Who cares if
you're only coasting at the end, at 100+ MPH :). The sooner you can
put wattage to the pavement, the higher your average speed will be,
and the sooner you'll get there. This seems to be pretty common in
EV racing, looking at the 1/8 mile speed and the 1/4 mile speed, it
looks like most of the accelerating is done pretty early, before
back EMF kills you, which I would think would happen earlier with caps.
Marty
----- Original Message ----- From: "Eidson, Mark" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, May 15, 2007 5:10 PM
Subject: RE: Using Audio Capacitors for Dragsters
The way I see it is that the current to the motor needs to be controlled
for traction and to distribute the energy over the length of the run so
that there is enough voltage left at the top end to generate HP need to
keep accelerating. If you were to dump the caps directly on the motor
most likely something will break if not traction, the driveline and
there will be nothing left at the top end. me
--- End Message ---
--- Begin Message ---
Frank, sorry, I meant to add that I think PM motors are O.K. for M/C
application since they are more available in small hp sizes. It just means
that your controller must work a little harder and gear ratios and gear
selection become more important than with a series motor.
For example, you could not down shift at high speed without tearing up the
drive train unless you have a series chopper regulated regen.
I have an AC drive in process for a M/C. I think I will be 100 years old
before it is finished!
--- End Message ---
--- Begin Message ---
Does anyone have firsthand experience with the DMOC445?
How many parameters can you adjust for stuff like regen etc. with
software on a computer or whatever?
I think I might end up going with it because the Siemens stuff from
metric mind is so much more expensive.. especially the motors and i
think he said that they only sell the controller with a motor.
Still not sure what to do.
I do live in Alaska so over heating the motor is not as much a
problem as say Florida or Southern California. Even though the water
cooled system would be nice for heating the cabin.
Tehben
--- End Message ---
--- Begin Message ---
Jack, electrics challenge us that have experience in racing ICE's. Here,
RPM is not your friend past a point determined by the motor design. You're
really not limited by the motor horsepower capability so much as what the
batteries can put out, and whether you can summon enough voltage to generate
power as back EMF kills off the current. I think of it as the batteries
putting out the horsepower, the motor just has to pass it on. Compared to
ICE, it'd be more like the size of your fuel line is your limit, not the
size of your engine. The problem is that at first, you need low voltage but
high current, which is easy, so you're traction limited. As speed goes up,
RPM goes up, motor voltage goes up until you reach pack voltage, then
current goes down, and available wattage from the batteries goes down.
Electric motors in practice don't keep putting out more power as RPM climbs.
The challenge is matching everything to try to overcome this basic bad news.
In practice, even if you have the wattage in the batteries to overcome the
traction at lower speeds, you will tend to be limited by pack voltage once
RPM climbs. Notice that electric drag cars are classed by battery voltage,
not motor horsepower.
Marty
----- Original Message -----
From: "Jack Murray" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, May 15, 2007 6:55 PM
Subject: Re: Using Audio Capacitors for Dragsters
umm, bill I've been drag racing since the 70's, and just sold my 506ci
stroker motor low-12 second street-driven drag car a few months ago.
So you are saying you can't go faster because you can't use the additional
power? That is funny... So the ProStock motorcycles that run 7's (or is
it 6's now) can't use more power and are traction limited????? Maybe you
need a better chassis, or bigger tires.
But speaking of caps, for a motorcycle you are really limited on space, so
caps might not be possible given their very low volume-to-power factor.
Jack
--- End Message ---
--- Begin Message ---
OK, so I looked up the specific power of Ness caps, and the spec sheet
shows 8500 Watts/kg, and your beloved A123 cells are 4999 Watts/kg when
discharged at a crushing short lifetime rate of 100C, and at the only
way short lifetime rate of 30C they are 2700 Watts/kg, according to the
chart by A123, http://www.a123systems.com/images/charts/highPower.jpg
Nuff said?
Jack Murray
Bill Dube wrote:
A transmission has weight and the parts spin. These things slow you down
on the drag strip.
Again, just do a few basic calculations. You will discover that caps
just can't provide the watt-hrs/kg that you need to get to the end of
the drag strip. Batteries out-perform caps in both specific power and
specific energy.
Indeed, it is best if you can stay at the traction limit at the
beginning and not worry so much about later on. Easier said than done,
however.
Bill Dube'
At 04:58 PM 5/15/2007, you wrote:
Well, if you had unlimited energy in zero weight batteries, then you'd
want to stay right on the brink of breaking loose the whole way. In
practice, I think it would require a continuously variable
transmission to keep the RPM under control to get anywhere close to
that point. But is there such a thing as a battery pack that can dump
that much wattage anyway? Certainly caps alone would be dropping
their voltage much faster than the equivelent voltage in batteries,
since there is no flat spot in the discharge curve, so you'd have to
be actually pulling the RPM down with reduced gear reduction as the
cap voltage dropped? Either that or you need a trick
controller/inverter that can put out more voltage than it sees from
the caps, which I believe is the equivelent of an electrical CVT.
I think if the available energy is limited, you want to expend it as
early as possible within the bounds of traction. Who cares if you're
only coasting at the end, at 100+ MPH :). The sooner you can put
wattage to the pavement, the higher your average speed will be, and
the sooner you'll get there. This seems to be pretty common in EV
racing, looking at the 1/8 mile speed and the 1/4 mile speed, it looks
like most of the accelerating is done pretty early, before back EMF
kills you, which I would think would happen earlier with caps.
Marty
----- Original Message ----- From: "Eidson, Mark" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, May 15, 2007 5:10 PM
Subject: RE: Using Audio Capacitors for Dragsters
The way I see it is that the current to the motor needs to be controlled
for traction and to distribute the energy over the length of the run so
that there is enough voltage left at the top end to generate HP need to
keep accelerating. If you were to dump the caps directly on the motor
most likely something will break if not traction, the driveline and
there will be nothing left at the top end. me
--- End Message ---
--- Begin Message ---
Zapi Inc in North Carolina
PH: 919-789-4588
-----Original Message-----
From: [EMAIL PROTECTED]
To: ev@listproc.sjsu.edu
Sent: Tue, 15 May 2007 3:46 PM
Subject: Re: Electric Power Steering
Looks nice, you can do away with the hydraulics and go straight
electric.
Where do you buy those from?
On May 15, 2007, at 10:54 AM, [EMAIL PROTECTED] wrote:
I use the ZTA's all the time. They are rather pricey but do > exactly
what they profess.
I keep several in stock.
Shawn Llawless
-----Original Message-----
From: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Sent: Tue, 15 May 2007 1:55 PM
Subject: RE: Electric Power Steering
Try... http://www.electrofit-zapi.com/hfelecpowsteer.htm
MW
______________________________________________________________________>
__
AOL now offers free email to everyone. Find out more about what's >
free from AOL at AOL.com.
________________________________________________________________________
AOL now offers free email to everyone. Find out more about what's free
from AOL at AOL.com.
=0
--- End Message ---
--- Begin Message ---
--- Jack Murray <[EMAIL PROTECTED]> wrote:
> OK, so I looked up the specific power of Ness caps,
> and the spec sheet
> shows 8500 Watts/kg, and your beloved A123 cells are
> 4999 Watts/kg when
> discharged at a crushing short lifetime rate of
> 100C, and at the only
> way short lifetime rate of 30C they are 2700
> Watts/kg, according to the
> chart by A123,
>
http://www.a123systems.com/images/charts/highPower.jpg
> Nuff said?
Yes, Nuff said. The timeslips speak louder than
words.
- Steven Ciciora, BMS Designer for www.KillaCycle.com
>
> Jack Murray
>
>
> Bill Dube wrote:
> > A transmission has weight and the parts spin.
> These things slow you down
> > on the drag strip.
> >
> > Again, just do a few basic calculations. You will
> discover that caps
> > just can't provide the watt-hrs/kg that you need
> to get to the end of
> > the drag strip. Batteries out-perform caps in both
> specific power and
> > specific energy.
> >
> > Indeed, it is best if you can stay at the traction
> limit at the
> > beginning and not worry so much about later on.
> Easier said than done,
> > however.
> >
> > Bill Dube'
> >
> > At 04:58 PM 5/15/2007, you wrote:
> >
> >> Well, if you had unlimited energy in zero weight
> batteries, then you'd
> >> want to stay right on the brink of breaking loose
> the whole way. In
> >> practice, I think it would require a continuously
> variable
> >> transmission to keep the RPM under control to get
> anywhere close to
> >> that point. But is there such a thing as a
> battery pack that can dump
> >> that much wattage anyway? Certainly caps alone
> would be dropping
> >> their voltage much faster than the equivelent
> voltage in batteries,
> >> since there is no flat spot in the discharge
> curve, so you'd have to
> >> be actually pulling the RPM down with reduced
> gear reduction as the
> >> cap voltage dropped? Either that or you need a
> trick
> >> controller/inverter that can put out more voltage
> than it sees from
> >> the caps, which I believe is the equivelent of an
> electrical CVT.
> >>
> >> I think if the available energy is limited, you
> want to expend it as
> >> early as possible within the bounds of traction.
> Who cares if you're
> >> only coasting at the end, at 100+ MPH :). The
> sooner you can put
> >> wattage to the pavement, the higher your average
> speed will be, and
> >> the sooner you'll get there. This seems to be
> pretty common in EV
> >> racing, looking at the 1/8 mile speed and the 1/4
> mile speed, it looks
> >> like most of the accelerating is done pretty
> early, before back EMF
> >> kills you, which I would think would happen
> earlier with caps.
> >>
> >> Marty
> >>
> >>
> >> ----- Original Message ----- From: "Eidson, Mark"
> <[EMAIL PROTECTED]>
> >> To: <ev@listproc.sjsu.edu>
> >> Sent: Tuesday, May 15, 2007 5:10 PM
> >> Subject: RE: Using Audio Capacitors for Dragsters
> >>
> >>
> >> The way I see it is that the current to the motor
> needs to be controlled
> >> for traction and to distribute the energy over
> the length of the run so
> >> that there is enough voltage left at the top end
> to generate HP need to
> >> keep accelerating. If you were to dump the caps
> directly on the motor
> >> most likely something will break if not traction,
> the driveline and
> >> there will be nothing left at the top end. me
> >
> >
> >
>
>
____________________________________________________________________________________Pinpoint
customers who are looking for what you sell.
http://searchmarketing.yahoo.com/
--- End Message ---
--- Begin Message ---
I love PM motors for traction applications. They are relatively light
(Up to 35 HP from a 22 lb LMC motor) simple to customize, simple to
control. They don't overspeed downhill and require no closed loop
system for protection in case of drivetrain failure. They are easy to
work on providing you respect the magnets. If peak torque is your goal
then you may want to look elsewhere but for my motorcycle applications
the PM is superior to all other motor types I have tried. Stay tuned
to this channel. I have heard that new high voltage (120v+) 4 quadrant
PM motor controls are just around the corner from more than one
manufacturer. With system efficiencies above 90% this will be very nice
for your M-cycle.
Shawn
-----Original Message-----
From: [EMAIL PROTECTED]
To: ev@listproc.sjsu.edu
Sent: Tue, 15 May 2007 7:55 PM
Subject: Permanent magnet motor question
Can someone explain if there's any functional difference with a PM
motor
(compared with a DC series motor) from a user's standpoint? I see
angular-velocity
and torque constants listed but don't know if I understand
how these
are manifested in an application. Is RPM limited and will the motor
try to
achieve that speed even under load? I like the light weight and the
potential
for regen appeals to me for another m-cycle project I'm thinking about.
TIA for explanations on how these things work.
_________________________________________________________________________
___________
Get your own web address.
Have a HUGE year through Yahoo! Small Business.
http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
________________________________________________________________________
AOL now offers free email to everyone. Find out more about what's free
from AOL at AOL.com.
--- End Message ---
--- Begin Message ---
Pro-Stock bikes are traction limited probably to the half-way point
on the track. Top fuel bikes are traction limited to probably 3/4s of
the way down the track. You can't effectively use airfoils for down
force on a bike, so there is only so much HP you can link up on the
back half. (We aren't to that limit with the KillaCycle, yet.)
You hold the tire at the traction limit until you reach the HP limit
of the battery pack. Then you do your best to continue to feed that
maximum HP to the motors the rest of the way down the track.
It is all about HP to weight with enough energy to keep it up the
length of the track. There really is not much of a volume/HP issue as
the drive package is so compact. You can also make the bike a bit
longer without much of a penalty.
It is not a matter of optimizing the machine for one style of power
source over another. You must feed the tire what it needs for as long
as you can. It is that simple.
You really need to just do the math and it becomes obvious that caps
just won't hack it on the drag strip compared to batteries. You can't
get blood from a stone. You pick the technology that will give you
the most HP/kg and then will also be able to give you the energy/kg
to at least go the distance down the track. If the HP/kg is not good
enough, the pack weight grows and if the energy/kg is not good
enough, the pack weight also grows. It takes BOTH to get you down the
track quickly. The physics won't let you go fast with just one or the other.
Unless you are willing to do the calculation to prove this to
yourself, you are just going to have to trust me on this.
Bill Dube'
--- End Message ---
--- Begin Message ---
I have been seeing alot of low numbers on this thread. Most of the numbers
are from battery to wheels which I suppose gives vehicle efficiency. From a
more practical "how much does it cost per mile" point of view, the numbers
should be AC kilowatt hours per mile and then the cents per mile. I see the
phrase " it only costs me pennies a day to drive" quite bit. That may be
true if you consider S2.25 as 225 pennies. I have a VW rabbit pickup, 120v
of T-125, Curtis 400 amp. The truck is not yet aerodynamically optimized.
Even with a light foot I average 15Kwh for 30 miles. So 2 miles per Kwh or
500Whr per mile.Here in NJ, 15 cents Kwh or $2.25 for 30 miles, or 7.5 cents
per mile. I'm sure I can get those numbers a bit better, but probably not by
much. Believe me, I have spent alot of time to make this truck as efficient
as possible, it only weighs 3300lbs (without passengers) which is the GVWR
of the truck. I am using a Zivan charger which, from what I have read on the
list, tends to overcharge a bit.
Its pretty hard for me to make a case for EV's to people who inevitably ask
how much it costs to drive. And I haven't included battery costs yet :(
Al
--- End Message ---
--- Begin Message ---
Shawn, Just a couple of probably unimportant thoughts: PM motors always
run at full field strength so that eddy current losses are higher than wound
field motors, depending on application and motor design, ie, laminated frame
vs solid frame. Most PM's I have seen have solid frames.
I have also had trouble extracting armatures from PM motors and reinserting
them w/o magnet damage. How do you do it?
On Tue, 15 May 2007 21:35:19 -0400, lawlessind wrote
> I love PM motors for traction applications. They are relatively
> light
> (Up to 35 HP from a 22 lb LMC motor) simple to customize, simple to
> control. They don't overspeed downhill and require no closed loop
> system for protection in case of drivetrain failure. They are easy
> to work on providing you respect the magnets. If peak torque is your
> goal then you may want to look elsewhere but for my motorcycle
> applications the PM is superior to all other motor types I have
> tried. Stay tuned to this channel. I have heard that new high
> voltage (120v+) 4 quadrant PM motor controls are just around the
> corner from more than one manufacturer. With system efficiencies
> above 90% this will be very nice for your M-cycle.
>
> Shawn
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> To: ev@listproc.sjsu.edu
> Sent: Tue, 15 May 2007 7:55 PM
> Subject: Permanent magnet motor question
>
> Can someone explain if there's any functional difference with a PM
> motor
> (compared with a DC series motor) from a user's standpoint? I see
> angular-velocity
> and torque constants listed but don't know if I
> understand how these are manifested in an application. Is RPM
> limited and will the motor try to achieve that speed even under
> load? I like the light weight and the potential for regen appeals
> to me for another m-cycle project I'm thinking about.
>
> TIA for explanations on how these things work.
>
> _________________________________________________________________________
> ___________
> Get your own web address.
> Have a HUGE year through Yahoo! Small Business.
> http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
>
> ________________________________________________________________________
> AOL now offers free email to everyone. Find out more about what's
> free from AOL at AOL.com.
--- End Message ---
--- Begin Message ---
Al writes:
>
> I have been seeing alot of low numbers on this thread. Most of the numbers
> are from battery to wheels which I suppose gives vehicle efficiency.
More numbers for you: My Geo Prizm uses about 280wh per mile, as measured
by the E-Meter and speedo. This is for a 17 mile commute that consists of
about 5 miles of surface streets and 12 miles of freeway, and includes a
significant hill/grade in the middle of the freeway section.
It would cost me about $15-$18 per month to recharge my car if my employer
didn't provide free charging at work. So my out-of pocket expense is about
$9-$10 per month (plus the three dozen donuts I bring to work once a month).
Ralph
--- End Message ---
--- Begin Message ---
Buy the caps, build the bike, and you will see for yourself that they
are not as good as batteries. It is much cheaper to just take the
time to do a few calculations, however.
The caps deliver this maximum specific power only when fully charged.
The specific power is proportional to the voltage squared. (This is
what bites you in the ass.) The voltage goes down in proportion to
the square root of the energy you have removed.
You need the specific power at the END of the strip, (perhaps the
middle might do) not at the beginning. How much specific power will
the caps deliver at the end of the strip?
It takes about 500 Watt-hrs to push the KillaCycle down the strip. If
you remove this much energy from a pack of caps, how much must it
weigh to still deliver 350 HP?
Keep in mind that if the pack of caps weighs anything more than 175
lbs this will increase the HP requirement AND the energy requirement
and thus make the pack even BIGGER!
I have actually done the calculations. Either you can trust
my analysis, or do the calculations yourself.
Bill Dube'
At 07:03 PM 5/15/2007, you wrote:
OK, so I looked up the specific power of Ness caps, and the spec
sheet shows 8500 Watts/kg, and your beloved A123 cells are 4999
Watts/kg when discharged at a crushing short lifetime rate of 100C,
and at the only way short lifetime rate of 30C they are 2700
Watts/kg, according to the chart by A123,
http://www.a123systems.com/images/charts/highPower.jpg
Nuff said?
Jack Murray
Bill Dube wrote:
A transmission has weight and the parts spin. These things slow you
down on the drag strip.
Again, just do a few basic calculations. You will discover that
caps just can't provide the watt-hrs/kg that you need to get to the
end of the drag strip. Batteries out-perform caps in both specific
power and specific energy.
Indeed, it is best if you can stay at the traction limit at the
beginning and not worry so much about later on. Easier said than done, however.
Bill Dube'
At 04:58 PM 5/15/2007, you wrote:
Well, if you had unlimited energy in zero weight batteries, then
you'd want to stay right on the brink of breaking loose the whole
way. In practice, I think it would require a continuously
variable transmission to keep the RPM under control to get
anywhere close to that point. But is there such a thing as a
battery pack that can dump that much wattage anyway? Certainly
caps alone would be dropping their voltage much faster than the
equivelent voltage in batteries, since there is no flat spot in
the discharge curve, so you'd have to be actually pulling the RPM
down with reduced gear reduction as the cap voltage
dropped? Either that or you need a trick controller/inverter that
can put out more voltage than it sees from the caps, which I
believe is the equivelent of an electrical CVT.
I think if the available energy is limited, you want to expend it
as early as possible within the bounds of traction. Who cares if
you're only coasting at the end, at 100+ MPH :). The sooner you
can put wattage to the pavement, the higher your average speed
will be, and the sooner you'll get there. This seems to be pretty
common in EV racing, looking at the 1/8 mile speed and the 1/4
mile speed, it looks like most of the accelerating is done pretty
early, before back EMF kills you, which I would think would happen
earlier with caps.
Marty
----- Original Message ----- From: "Eidson, Mark" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, May 15, 2007 5:10 PM
Subject: RE: Using Audio Capacitors for Dragsters
The way I see it is that the current to the motor needs to be controlled
for traction and to distribute the energy over the length of the run so
that there is enough voltage left at the top end to generate HP need to
keep accelerating. If you were to dump the caps directly on the motor
most likely something will break if not traction, the driveline and
there will be nothing left at the top end. me
--- End Message ---
--- Begin Message ---
Dave Cover writes:
>
> Excellent. Does anyone know where to find a spec on Regbus?
http://www.manzanitamicro.com/download.htm
Ralph
--- End Message ---
--- Begin Message ---
Well, you've already bumped up against the main problem. If you go with the
Metricmind stuff you will have a reliable source for any questions you want
to ask. With the DMOC445 maybe/maybe not...
damon
From: Tehben Dean <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Solectra/Azure Dynamics DMOC445 AC controller
Date: Tue, 15 May 2007 16:56:01 -0800
Does anyone have firsthand experience with the DMOC445?
How many parameters can you adjust for stuff like regen etc. with software
on a computer or whatever?
I think I might end up going with it because the Siemens stuff from metric
mind is so much more expensive.. especially the motors and i think he said
that they only sell the controller with a motor.
Still not sure what to do.
I do live in Alaska so over heating the motor is not as much a problem as
say Florida or Southern California. Even though the water cooled system
would be nice for heating the cabin.
Tehben
_________________________________________________________________
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Marty wrote:
You're really not limited by the motor horsepower capability so much as what the
batteries can put out,
If that's the case then. If I had a 60 pack just like John's, and the
big Z2K, what's the ideal motor setup(available DC, can be multiple
motors)?
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Al, I know several EV owners that have solar panels. Their power is "free"
at least some of the time. I suppose it would be more practical in Arizona
than N.J.
Solar panels take about 10 years to pay back when compared to present
electrical rates. The pay back when compared to present (and near future?)
gasoline cost is much quicker. I plan to have solar panels on my next EV
which will be a small pick up. I calculate that I can add about one mile of
range for every good hour of sunshine while parked at work.
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Well Asure Dynamics is still around producing stuff like hybrid
drives and they have the controller and motor on there website.
Wouldn't the people at Electro Automotive be able to provide
support?... anyway I set an email asking that very question to EA today.
But yah I am not quite sure what to do at the moment.
Tehben
On May 15, 2007, at 6:19 PM, damon henry wrote:
Well, you've already bumped up against the main problem. If you go
with the Metricmind stuff you will have a reliable source for any
questions you want to ask. With the DMOC445 maybe/maybe not...
damon
From: Tehben Dean <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Solectra/Azure Dynamics DMOC445 AC controller
Date: Tue, 15 May 2007 16:56:01 -0800
Does anyone have firsthand experience with the DMOC445?
How many parameters can you adjust for stuff like regen etc. with
software on a computer or whatever?
I think I might end up going with it because the Siemens stuff
from metric mind is so much more expensive.. especially the
motors and i think he said that they only sell the controller
with a motor.
Still not sure what to do.
I do live in Alaska so over heating the motor is not as much a
problem as say Florida or Southern California. Even though the
water cooled system would be nice for heating the cabin.
Tehben
_________________________________________________________________
More photos, more messages, more storage—get 2GB with Windows Live
Hotmail. http://imagine-windowslive.com/hotmail/?locale=en-
us&ocid=TXT_TAGHM_migration_HM_mini_2G_0507
--- End Message ---
--- Begin Message ---
I'll take a stab.
First keep this point in mind. A motor is a generator and a motor at the
same time. The torque is a result of the current that is generated by
the difference of these two voltages and the motors reactance(resistance
for us dc guys)
A series motor has the same current in the field and armature (hince the
term series) Since torque is proportional to amps the series motor shows
a squared curve because when they both contribute they contribute almost
equally
T| *
O| *
r| *
Q| *
U| *
E| *
| * *
|__________*****_
0 max rpm
When the series motor starts to get to that point were the voltage
generated is preventing any more current to flow, we can weaken the
field by putting a resistor accross it. This allows there to be a
difference and more current flows allowing extended rpm operation. If
this field shorts or goes open and the voltage goes to zero the rpm goes
to infinity if there is no load "Bammm!" Even if the field is intact,
removing the load on a series motor can end in a disaster as the field
naturally goes to zero as the rpm's climb.
In a PM or a shunt motor the field is fixed so the contribution is
limited on the small end and held up a little in the middle
T|
O|
r|*
Q| *
U| *
E| *
| *
|__________*_
0 max rpm
The field can't increase so low end torque is not as dramatic, the field
is stronger when normally the series would of dropped more and the field
can't become disconnected or if the load is removed the rpm goes to the
match point and stays there.
Magnets are like a wire, they have two components that can be thought of
as voltage and current. The density of the field and how far it reaches.
Ferrite magnets have low density and medium reach and reverse easily at
elevated magnetic field and heat
neobidium-iron have very high density, small to medium reach and much
higher resistance to reversing or heat than ferrite
Samrium-Cobolt have high density, close but not as good as
Neobidium-iron, but they can handle a much higher reversing field and
temperature.
most permanent magnet motors we can get use ferrite or the "ceramic"
variation
Servo's use the neobidium and military and high-end servos use
samrium-cobolt.
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----- Original Message -----
From: "Bill Dube" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, May 15, 2007 4:44 PM
Subject: Re: Using Audio Capacitors for Dragsters
> The battery current draw for a drag race can be roughly modeled as a
> ramp with plateau.
>
> If you do the calculations, you will very quickly discover that good
> quality AGM lead-acid batteries, like Hawker Genisys batteries, are
> far better than any capacitor on the market for drag racing. They are
> also a lot less expensive. It is all about W/kg and W-hrs/kg. You
> need some of both.
>
> Do the calculation and you will see for yourself. The caps (of all
> types and brands) just don't have the specific energy needed to get
> to the end of the track. Only very few (if any in reality) have as
> much specific power as A123 Systems cells (~4,000 W/kg when heated).
>
> Bill Dube'
>
> Hi EVerybody;
Sure seems to my uneducated in drag racing mind that TRACTION is the
major issue here, as we, Bill, get into more powerful Badd-eries!? Seeing
the Orange Juice scrabbling for traction going down the trak in FLA back in
Jan. To a point where he just couldn't use the power being dished out by
those amazing a123's! Seems like dragster chassis are no suspension
setups(do they, other than lethe frames) depending on the tires '
stickiness, to get power to the road. Weight plays a part, to a point? Too
heavy and ya don't go, to light, all you do is wheel spin?Lets say Plasma
Boy stuffed the Zoombie with A 123's, Maybe he'd be able to punch into the
low 11'sIF he could stay stuck too the trak? Would he be too light?I think
he NEEDS several hundred lbs of battery as ballast?Or tubbed out body, REAL
slicks in back?Or IF I were to drive it? Scare the s**t out of me but WOULD
be fun!Being about 300 lbs instead of Tim's probably near HALF that? Or Tim
and John rode it together. More ballast? better times? To a point.When ya
think of it, drag racing is defying the laws of physics, anyhow? John Force
with his absurd 330 MPH in the Quarter? Or other Top Fuel guyz? Short of a
surplus aircraft carrier catapult? THAT would take care of the traction
issue, once and for all<g>!Solving the traction issue, better badder
batteries, simply MORE power? Jim Husted is giving thought to this, I'm
sure? siamese 9"s 11's 13"'s Cables the size of my arms. Bigger Zillas? Stay
tuned we have only just begun? If gas can do it, so can we?The 200's in our
lifetime?300's? Scary!
OK back to reality
Seeya
Bob
>
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----- Original Message -----
From: "Michael" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, May 15, 2007 4:36 PM
Subject: Re: Solar boat completes Atlantic crossing - Green Machines -
MSNBC.com
> > Not to diss this guy, but had he a clipper ship, or just a good SAIL
> > boat, cat, if you will, he woulda been here MONTHS ago. Or I believe a
12
> > day sailing record STILL stands, not sure if it was a clipper or fancy
> > Catamaran? I think ROWING guyz have made better time?
>
> A British four-man crew set a world record for rowing across the Atlantic,
> crossing the ocean in 39 days to win the Atlantic Rowing Race on Sunday.
> http://news.bbc.co.uk/sport1/hi/other_sports/rowing/4576918.stm
> I had a rowboat as a kid! Makes me tired to just THINK of that!
> Peyron and his crew took four days eight hours and 23 minutes 54 seconds
> to sail from New York to Cornwall.
> http://news.bbc.co.uk/sport1/hi/other_sports/sailing/5156492.stm
> Wow! Thats as good as the Mauretania, Lusitania,France , others of the
Titanic era that burned THOUSANDS of tons of coal to run those times! This
is amazing.When all the oil is burned up THIS will be the 21th Century
Concorde! The Normandie and Queen Mary bested this, but not by much!
> ...but the point was he could do it at all. (Kontiki sailed it quicker.)
> Got a point, there.
Sea Ya
Bob
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I would like to work on improving the aerodynamics of my truck. Of course I
want to keep weight to a minimum.
I am considering LDPE, HDPE, and "Lexan" in say 3/32 or 1/8 thickness. Lexan
is probably best at impact resistance. Not sure if low or high density poly
would be a good choice as it costs less than Lexan. Thanks for any comments.
Al
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>>>>> "Al" == Al <[EMAIL PROTECTED]> writes:
Al> Even with a light foot I average 15Kwh for 30 miles. So 2 miles per
Al> Kwh or 500Whr per mile.Here in NJ, 15 cents Kwh or $2.25 for 30
Al> miles, or 7.5 cents per mile....
Al> Its pretty hard for me to make a case for EV's to people who
Al> inevitably ask how much it costs to drive. And I haven't included
Al> battery costs yet
At the prevailing price around here (about $3.40/gal) and assuming my Volvo
averages about 18 mpg (which is about what it's averaged over the life of
the car - mostly around town driving) I'm paying 18.9 cents per mile just
for gas. 7.5 cents per mile doesn't sound so bad. I don't know what your
battery costs work out to. Tossing out some ballpark figures: 12 batteries
at about $75 a pop which last for 30,000 miles (is that too optimistic?)
only tacks on another 3 cents per mile. Drop it to 10,000 miles and you're
still only at 9 cents per mile. Are my guesses way off base?
--
Skip Montanaro - [EMAIL PROTECTED] - http://www.webfast.com/~skip/
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Anyone have experience with the Zivan NG1 DC/DC ?
Looks like a beefy unit, 55amp continuous!
Thanks, Al
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Its a forgotten small detail, but if everyone converted to EV's, state and
federal road taxes now applied to gasoline would have to be added to the
cost of electricity, boosting the electrical cost/mile somewhat.
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Well, if EA or Azure will offer some kind of support then you should be in
pretty good shape. I just know there is not a lot of chatter on this list
about these systems. I also know that with Metricmind you get a quality
product and top notch support. I've also heard nothing but good about EA
and the fact that they are one of the few compainies that has been able to
sustain an EV based business speaks volumes.
From: Tehben Dean <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: Solectra/Azure Dynamics DMOC445 AC controller
Date: Tue, 15 May 2007 18:29:37 -0800
Well Asure Dynamics is still around producing stuff like hybrid drives and
they have the controller and motor on there website. Wouldn't the people
at Electro Automotive be able to provide support?... anyway I set an email
asking that very question to EA today.
But yah I am not quite sure what to do at the moment.
Tehben
On May 15, 2007, at 6:19 PM, damon henry wrote:
Well, you've already bumped up against the main problem. If you go with
the Metricmind stuff you will have a reliable source for any questions
you want to ask. With the DMOC445 maybe/maybe not...
damon
From: Tehben Dean <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Solectra/Azure Dynamics DMOC445 AC controller
Date: Tue, 15 May 2007 16:56:01 -0800
Does anyone have firsthand experience with the DMOC445?
How many parameters can you adjust for stuff like regen etc. with
software on a computer or whatever?
I think I might end up going with it because the Siemens stuff from
metric mind is so much more expensive.. especially the motors and i
think he said that they only sell the controller with a motor.
Still not sure what to do.
I do live in Alaska so over heating the motor is not as much a problem
as say Florida or Southern California. Even though the water cooled
system would be nice for heating the cabin.
Tehben
_________________________________________________________________
More photos, more messages, more storageget 2GB with Windows Live
Hotmail. http://imagine-windowslive.com/hotmail/?locale=en-
us&ocid=TXT_TAGHM_migration_HM_mini_2G_0507
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