EV Digest 6947
Topics covered in this issue include:
1) Re: How low can you go?
by Lee Hart <[EMAIL PROTECTED]>
2) RE: regarding the Solectria Sunrise
by "Beth Silverman" <[EMAIL PROTECTED]>
3) Re: Understanding my motor (ADC L91 & X91 6.7" motors revisited)
by Lee Hart <[EMAIL PROTECTED]>
4) Re: regarding the Solectria Sunrise
by "Evan Tuer" <[EMAIL PROTECTED]>
5) Re: 55 MPH Part III
by "Phil Marino" <[EMAIL PROTECTED]>
6) Selling or buying an EV
by bruce parmenter <[EMAIL PROTECTED]>
7) RE: Selling or buying an EV
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
8) Re: regarding the Solectria Sunrise
by "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
9) Vectrix demo
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
10) 1200 Raptor help !
by Jeff Mccabe <[EMAIL PROTECTED]>
11) Re: VOLTS vs AMPS & RE: Make It
by Ian Hooper <[EMAIL PROTECTED]>
12) Re: vroombox and EV ?
by john fisher <[EMAIL PROTECTED]>
13) Re: Make it
by Eric Poulsen <[EMAIL PROTECTED]>
14) Re: Understanding my motor (ADC L91 & X91 6.7" motors revisited)
by Jeff Major <[EMAIL PROTECTED]>
15) Re: regarding the Solectria Sunrise
by [EMAIL PROTECTED]
16) Re: regarding the Solectria Sunrise
by "Zeke Yewdall" <[EMAIL PROTECTED]>
17) Re: 55 MPH Part III Oops - equation error
by "Phil Marino" <[EMAIL PROTECTED]>
18) Re: FW: Regen with Sevcon and Etek
by [EMAIL PROTECTED]
19) More folks converting cars to electric...
by [EMAIL PROTECTED]
20) New EV controller to hit the market
by Michael Barkley <[EMAIL PROTECTED]>
21) Re: VOLTS vs AMPS
by Victor Tikhonov <[EMAIL PROTECTED]>
22) Re: 55 MPH Part III
by Victor Tikhonov <[EMAIL PROTECTED]>
23) Re: Selling or buying an EV
by "John G. Lussmyer" <[EMAIL PROTECTED]>
24) Re: vroombox and EV ?
by GWMobile <[EMAIL PROTECTED]>
--- Begin Message ---
[EMAIL PROTECTED] wrote:
The Optima data sheet indicates that 10.5 volts is the cut off low
voltage for the reserve capacity.
Should that voltage also be considered the maximum “sag” voltage during
a high current draw regardless of the state of charge or sag time?
Yes; 10.5v is a good safe cutoff voltage regardless of current. You are
very unlikely to reverse a cell if you don't go below this.
If you *know* all cells are matched, and are trying to produce big
numbers for a data sheet, you can discharge below this point. Battery
manufacturers do this on their data sheets to inflate the amphour ratings.
The real danger is that when a cell goes completely dead, it develops
high resistance. The other cells in series with it, that still have
charge, will force current to keep flowing through the dead cell. This
high current and high resistance cause severe heating in the dead cell.
The plates will warp, it will boil its electrolyte, and things will get
very bad very fast!
So, the 10.5v limit comes from the assumption that 1 cell out of the 6
in a 12v battery has gone dead. The 5 good ones are still delivering 2v
each (2 x 5 = 10v) and there is just 0.5v left across the dead one (1 x
0.5v = 0.5v), so there is 10.5v across the battery as a whole.
--
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 ---
Solectria is not out of business -- we merged with Azure Dynamics in
2005.
We are still at the same building where Solectria moved in 2001, outside
of Boston, Massachusetts.
Beth Silverman
***********************
-----Original Message-----
From: Lee Hart [mailto:[EMAIL PROTECTED]
Sent: Monday, June 25, 2007 10:53 AM
To: ev@listproc.sjsu.edu
Subject: Re: regarding the Solectria Sunrise
gulabrao ingle wrote:
> I was reading the other day of a car known as the Solectria Sunrise,
> but surprisingly there is no information available about the
> specifications of the car or how it could get 375 miles on a single
> charge.
Solectria is out of business, so most of what you find is old
information.
> Where can I get detailed information, blue prints, technical
> specifications or even some hi-res photos of this car?
From me! :-) I'm heading a team that is making a kit-car version of the
Sunrise.
> Are there any owners of this car on the list at present?
Yes, a number were sold to individuals. Stephen Taylor's is on the web
at http://www.austinev.org/evalbum/655
> What was so special about the construction of this car that it could
> get 375 miles on a charge?
The Sunrise is an example of what Amory Lovins calls a "hypercar". The
entire chassis and body are carbon fiber composites, very light and
strong, weighing about 400 lbs. It was designed from scratch as an EV,
and so avoided the usual losses and inefficiencies of the "make do"
parts you find in vehicles converted from ICEs. The range with ordinary
lead-acid batteries was around 100 miles on a charge. For the range
records, they used Ovonic nimh batteries (the same ones GM used in the
EV1 and Chevy S10 EV pickups).
> How costly was it?
About $100,000.
> Any information, pointers or links would be appreciated.
Here are the specs for the original Sunrise (in parentheses), and our
version that we are building now:
Dimensions
length 176"
width 74"
height 52"
wheelbase 104"
Weights
curb weight without batteries 1600 lbs (1433 lbs)
payload 750 lbs (682 lbs)
GVWR 3400 lbs (2979 lbs)
Drive system
100kw Netgain WarP 9" DC motor
Cafe Electric Zilla 2K controller
direct drive to rear wheels, via 5.14:1 differential
(50kw Solectria AC induction motor, inverter, driving
front wheels via Geo Metro transaxle)
Batteries
central battery tunnel slides out the front for easy servicing
size 120"L x 12"H x 15"W, 1500 lbs, holds up to 24 T-145 6v 240ah
(24 GM/Ovonic nimh, 12v 90ah)
Suspension
front: independent, double A-arm, from 1989-97 Ford Thunderbird
(1994 Geo Metro McPherson strut)
rear: independent, double A-arm, from 1989-97 Ford Thunderbird
(1994 Dodge Neon McPherson strut)
coil springs with air bags
power rack and pinion steering (manual rack and pinion) Brakes
power disk or drum, with/without ABS, from T'bird donor car
(manual, Geo Metro front disk, Dodge Neon drum rear)
regenerative braking
Tires
Goodyear Integrity P185/65R15, low rolling resistance
(13" Geo Metro tires)
Performance
0-30 mph: 3 seconds (6 seconds)
0-60 mph: 8 seconds (17 seconds)
range, lead-acid: 100 miles at 30 mph, 60 miles at 60 mph
(nimh: 400 miles at 30 mph, 200 miles at 60 mph)
--
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 ---
Richard Acuti wrote:
Since I have the L91, can I assume that the opposite applies? Fewer
commutator bars and windings so I will use more current to get a
given amount of torque and that means that I will probably use more
of my amps to accelerate to a particular speed but that I can get
more RPM's per volt?
Correct; you got it!
What does this mean for my driving style? Any recommendations?
Not much. The L91 and X91 are basically the same motor, wound for
different voltages. Since ADC only puts one wire in each slot, the X91
has more slots to get more turns in (and more commutator bars to connect
these extra wires to). The two motors are mechanically equivalent,
horsepower-wise.
For a given pack voltage and controller current limit, the L91 spins
faster and makes less torque. That just means you leave it in a lower
gear (higher gear ratio) a little longer. In other words, you shift a
little later than if you had an X91. But the car will accelerate the
same, because that's limited by the pack voltage and controller current
limit.
--
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 ---
On 6/25/07, Lee Hart <[EMAIL PROTECTED]> wrote:
gulabrao ingle wrote:
> I was reading the other day of a car known as the Solectria Sunrise,
> but surprisingly there is no information available about the
> specifications of the car or how it could get 375 miles on a single
> charge.
Solectria is out of business, so most of what you find is old information.
> Where can I get detailed information, blue prints, technical
> specifications or even some hi-res photos of this car?
From me! :-) I'm heading a team that is making a kit-car version of the
Sunrise.
It might be good to update the wikipedia entry for the Sunrise (
http://en.wikipedia.org/wiki/Solectria_Sunrise ), with this
information :)
--- End Message ---
--- Begin Message ---
Hi, Peter
I agree with your conclusions, and this is a good explanation, but some of
your units along the way might be a bit confusing to others. I'll insert
some clarifying comments within your post. ( Well, I hope they're
clarifying)
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: 55 MPH Part II
Date: Mon, 25 Jun 2007 07:38:26 -0700 (MST)
>>From what I've been reading it takes about 60 ft/lbs of torque to
>> maintain
> an average vehicle at 55mph.
>
> Or around 5-10HP.
>
HP = torque x RPM
Although this idea is sound, there are no commonly used units that make the
above equation true.
It might be clearer to say the HP = C x torque x RPM, where C = 5252
HP/ft-lb/RPM, and torque is in ft-lb, This is the number you give a bit
later on. I'll show where that number comes from.
If the motor has the HP to maintain the speed, but the torque is low, that
just means that the RPM is too high. Gear the RPM down and the torque
goes up by the same factor.
I.e. 1 HP = 5252 ft/lbs per minute.
Strictly speaking, 1 HP = 550 ft-lb/s = 33000 ft-lb/minute Notice that
the units are ft-lb, and not ft/lb. ft/lb is a unit of compliance ( the
inverse of stiffness). Ft-lbs are units of energy, so ft-lb/minute are
units of power.
However, ft-lbs are also units of torque, and this works also (as it must):
If you are talking about rotational power, 1 HP = 33000 ft-lb/ (radian/min)
. This is true because radians are dimensionless and have a value of 1. A
radian is that angle where the swept curve equals the radius. It's about 57
degrees., and exactly equal to 180 degrees/ PI.
Most people understand - and use - RPM (revolutions per minute) rather than
radians/ minute, so, if you convert this equation ( based on 2 x PI radians
= 1 rev) you get your (correct ) equation. (33000 / 6.28 = 5252. Or.
almost. It would be closer with a better approximation of 2 PI.
And, so, you are correct in all of the following statements,.
That would either be 5252 ft/lbs of torque at 1 RPM, or 1 ft/lb of torque
at 5252 RPM or 100 ft/lbs of torque at 52.52 RPM
So let's say your vehicle requires 8hp to go 55mph and that this works out
to 60 ft/lbs of torque at 700 rpm wheels. Let's say your motor 8hp, but
it's at 10 ft/lbs of torque and 4200 RPM. What you need is a transmission
(belt drive, chain drive, gears, etc.) with a 6:1 reduction ratio. That
will reduce the RPM from 4200 to 700 and increase your torque from 10
ft/lbs to 60 ft/lbs.
8HP into the transmission, 8HP out. The universe is happy and everything
works out.
Phil Marino
_________________________________________________________________
Dont miss your chance to WIN $10,000 and other great prizes from Microsoft
Office Live http://clk.atdmt.com/MRT/go/aub0540003042mrt/direct/01/
--- End Message ---
--- Begin Message ---
After my accident [ images http://geocities.com/brucedp/blazer/ ]
an EAA member let some of my local EAA members know my vehicle
was for sale or the parts there of.
While I waited for local interest, I noticed the availability of
used EVs or used EV parts has on the web dried up considerably.
It seems the price of fuel has jacked up the EV demand to drain
the supply of used EVs or used parts to nil.
The next day, my email box was full of inquiries. Because where
I live vehicle work is not allowed, the purchase of the whole
smashed vehicle is preferable to me (take it away Sam).
While I am in a tight financial position and getting the most
from my jam would be best (my main vehicle now is the bus), I
do not feel it is best to try to squeeze fellow or potential
EV'rs.
I plan to discount the total price of all the good EV parts
(batteries, motor, 4 speed manual transmission, link 10 emeter,
Russco heater/pump, Zivan chargers, etc.) and subtract the
price of towing the EV away. I think that would be a fair
price and a good deal for both parties.
Next, I need to explore the current CA DMV method to transfer
vehicle ownership. I have heard some horror stories of people
selling their ICE and then later receiving a ticket from the
police because the 'new' owner never turned in the DMV
paperwork.
Until the vehicle is legally transferred, the original owner
is subject to whatever dumb things the 'new' owner does. I
would like to avoid that situation.
...
Because the used EV market is so bone dry, my EV withdrawals
has me looking at what EVs 'are' available. Besides used GEM
nEVs, and new Zap's Xebra 40mph EVs, there really isn't any
EVs that are in the $15k range (sorry, no longer work for hp
which would give me my former income to afford a Tesla EV).
What do other List'rs think about this 'dry' situation?
Has it forced people to think they 'have to' purchase a nEV
or build their own EV conversion because that is all that is
available?
Old timers will remember the 1990's where there were plenty of
EV converters across the USA. Where are the EV converters now?
Are their EV conversion businesses growing or saturated with
work?
What do you think?
Bruce {EVangel} Parmenter
' ____
~/__|o\__
'@----- @'---(=
. http://geocities.com/brucedp/
. EV List Editor & AFV newswires
. (originator of the above ASCII art)
===== Undo Petroleum Everywhere
: MEPIS Linux & WiFi powered :
____________________________________________________________________________________
Bored stiff? Loosen up...
Download and play hundreds of games for free on Yahoo! Games.
http://games.yahoo.com/games/front
--- End Message ---
--- Begin Message ---
Bruce,
Couldn't you just get another S15 blazer and transplant your
parts into it?
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of bruce parmenter
Sent: Monday, June 25, 2007 12:21
To: evlist
Subject: Selling or buying an EV
After my accident [ images http://geocities.com/brucedp/blazer/ ] an EAA
member let some of my local EAA members know my vehicle was for sale or
the parts there of.
While I waited for local interest, I noticed the availability of used
EVs or used EV parts has on the web dried up considerably.
It seems the price of fuel has jacked up the EV demand to drain the
supply of used EVs or used parts to nil.
The next day, my email box was full of inquiries. Because where I live
vehicle work is not allowed, the purchase of the whole smashed vehicle
is preferable to me (take it away Sam).
While I am in a tight financial position and getting the most from my
jam would be best (my main vehicle now is the bus), I do not feel it is
best to try to squeeze fellow or potential EV'rs.
I plan to discount the total price of all the good EV parts (batteries,
motor, 4 speed manual transmission, link 10 emeter, Russco heater/pump,
Zivan chargers, etc.) and subtract the price of towing the EV away. I
think that would be a fair price and a good deal for both parties.
Next, I need to explore the current CA DMV method to transfer vehicle
ownership. I have heard some horror stories of people selling their ICE
and then later receiving a ticket from the police because the 'new'
owner never turned in the DMV paperwork.
Until the vehicle is legally transferred, the original owner is subject
to whatever dumb things the 'new' owner does. I would like to avoid that
situation.
...
Because the used EV market is so bone dry, my EV withdrawals has me
looking at what EVs 'are' available. Besides used GEM nEVs, and new
Zap's Xebra 40mph EVs, there really isn't any EVs that are in the $15k
range (sorry, no longer work for hp which would give me my former income
to afford a Tesla EV).
What do other List'rs think about this 'dry' situation?
Has it forced people to think they 'have to' purchase a nEV or build
their own EV conversion because that is all that is available?
Old timers will remember the 1990's where there were plenty of EV
converters across the USA. Where are the EV converters now?
Are their EV conversion businesses growing or saturated with work?
What do you think?
Bruce {EVangel} Parmenter
' ____
~/__|o\__
'@----- @'---(=
. http://geocities.com/brucedp/
. EV List Editor & AFV newswires
. (originator of the above ASCII art)
===== Undo Petroleum Everywhere
: MEPIS Linux & WiFi powered :
________________________________________________________________________
____________
Bored stiff? Loosen up...
Download and play hundreds of games for free on Yahoo! Games.
http://games.yahoo.com/games/front
--- End Message ---
--- Begin Message ---
> What was so special about the construction of this car
> that it could get 375 miles on a charge ?
It was partly a battery with a high specific energy, and partly detailed
attention to high
energy efficiency.
The Sunrise was a purpose built EV design with composite structure and was very
light. It had good aerodynamics and a lightweight, low friction drivetrain.
The AC
induction motor and controller were built to be as efficient as possible. The
battery
was Nickel Metal Hydride from Ovonics. Every element of the design was
carefully
optimized for the highest possible efficiency consonant with a design that
could be
mass-produced.
Regrettably, the Sunrise was never offically produced. Like many other R&D
oriented
companies, Solectria didn't want to manufacture it themselves, but rather hoped
to
license the design to an experienced automaker. Solectria already had a
relationship
with GM, who were supplying gliders for the Force. Perhaps Solectria thought
that in
the end GM would have to meet its EV sales mandates under California's Braude
Initiative, and that GM might license their design for a quick entry into EVs.
That's
pure speculation on my part, though. In any event, as you may know, GM took a
rather different approach to addressing the Braude Initiative.
> How costly was it ?
It was never officially offered for sale to the public. At one time, Solectria
were said to
be willing to hand-build a Sunrise for those who could afford it. I heard
rumors of
quotations for a hand built copy, from $100,000 to I think $300,000. I don't
know
whether any were built for this purpose.
Reportedly Azure Dynamics, which purchased Solectria a few years ago, is not
interested in commercializing the Sunrise design. However, the design's
current
status isn't clear to me.
Azure and/or James Worden, who designed the car, sold off some or most of the
prototypes. Several EV hobbyists bought them, and a couple have expressed
interest in trying to reproduce the design. My understanding is that James
Worden
isn't opposed to this, and presumably Azure isn't. However, whether any of
these
hobbyists actually has a signed document giving him the legal right to use the
Sunrise
design, I don't know.
> Are there any owners of this car on the list at present ?
Lee Hart has one of the prototypes, and is one of the enthusiasts trying to
reproduce
it. He is working on turning the Sunrise into a kit car. Perhaps it would be
more
accurate to say that he is designing a kit car that looks like the Sunrise and
is based
on its design.
I have a great deal of respect for Lee, but I must say that from his
description I doubt
that the result will have the range of the original. (But I don't think that's
his objective;
see below.) Although the body will still be aerodynamic, I believe he is using
a
construction method that differs from Solectria's. I don't know how this will
affect the
weight.
His most substantial changes are in the drivetrain. As I understand it, the
original
used mostly Geo Metro (Suzuki Forsa?) suspension parts, one of Solectria /
Brusa's
purpose built lightweight, low loss transaxles driving the front wheels, and a
well-tuned
lightweight AC induction motor and inverter combination.
Lee is using a DC motor instead of the AC motor. It would be difficult for
such a motor
to match the very light weight of the original Solectria Sunrise motor.
His motor will drive the rear wheels, rather than the front. It will use a
drive axle from a
Thunderbird. This has to be appreciably heavier (but no doubt cheaper and more
readily available) than the very light, custom designed front drive transaxle
of the
original.
I believe the car will most likely use lead batteries. There are very few
practical and
affordable options for using NiMH batteries in road EVs. Probably lithium
batteries
could be fitted.
Each of these changes (other than the battery change) should have a modest
effect on
the vehicle's efficiency and range. However, in the aggregate, I think they'll
result in an
EV with sexy looks and good, though not spectacular, range. Assuming that Lee
can
get 50% or more of the vehicle weight in batteries, it should be able to break
100 miles
on lead. With lithium batteries, perhaps it could achieve 200 miles or more.
That's
fine performance, though it's not 375 miles.
Of course, I could be wrong, and time will tell.
I think that part of the original Sunrise's secret to incredible range was
James
Worden's attention to detail. It seems to have been in his nature to squeeze
the last
percentage point of efficiency out of each component.
Lee is an outstanding engineer too, but I think a rather different one from
Worden. Lee
reminds us, quite correctly, that "the perfect is the enemy of the good." I
think he'll
make the Sunrise II good - very good. It will be an efficient EV, surely more
so than
the typical conversion. I also expect it to be affordable, costing a fraction
of the lowest
price Solectria quoted.
I don't think it will be as efficient as the original Solectria Sunrise, and I
doubt that it
will approach the Sunrise's remarkable range. However, it will be an EV kit
(and
perhaps eventually a turnkey EV) that hundreds or thousands of people can buy,
something that Solectria never achieved with the design.
> Where can I get detailed information, blue prints,
> technical specifications or even some hi-res photos of this car ?
I don't know. Maybe if you flew over to the States, one of the owners of a
prototype
would let you examine it.
PS - You may get more responses to your messages on the EVDL if you configure
your email to send plain text. When you send multipart alternative html
messages, as
you did here, some list members will see only this :
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
* ---REMAINDER OF MESSAGE TRUNCATED--- *
* This post contains a forbidden message format *
* (such as an attached file, a v-card, HTML formatting) *
* Lists at sjsu.edu only accept PLAIN TEXT *
* If your postings display this message your mail program *
* is not set to send PLAIN TEXT ONLY and needs adjusting *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
David Roden
EVDL Administrator
http://www.evdl.org/
--- End Message ---
--- Begin Message ---
I have been offered a Vectrix to ride in return for my thoughts on the bike.
To save time maybe it would be good to do this at a SFEVA meeting. Maybe
some of the South, North & East Bay interested individuals could come see it
at that meeting. I can have the bike after this Tuesday. Maybe other
groups & individuals would like a demo ride. I'll be glad to hook up.
Jerry P. Please contact me. Lawrence Rhodes.....
--- End Message ---
--- Begin Message ---
Tried to wakeup(unsuccessfully) my raptor controller
for the first time this weekend in my porsche.
Would love to talk to someone familar with it, to try
and trouble shoot whats wrong. Could you please
contact me off list, or call my work number below. I
live in San Jose, ca.
Thanks,
Jeff Mccabe
work 408-845-3746
home 408-998-0340
--- End Message ---
--- Begin Message ---
OK, I wasn't picking on their component choice so much as saying you
can build your own speed controller for a lot less than it costs to
*buy* a Curtis. The retail price of the 1221s is about $1100,
correct? For power stage component cost, going on quantities of 1000
units, prices from digikey are:
32x 220uF 200VDC electro caps @ $0.87ea = $27.84
36x BUZ30A @ $1.13ea = $40.68
12x 300V 60A diodes @ $1.08ea = $12.96 (couldn't find SR4180R-C,
this is actually the higher-rated STTH60P03SWs)
TOTAL = $81.48
So, $1100 seems a bit much to me. I realise these three components
aren't the only expense, but still..
As for component selection, they're fine I guess but I tend to think
it's more elegant to go with a smaller number of higher-rated semis,
such as the IXFK120N20 (200V 120A 0.017ohm MOSFET) @ ~$10ea or the
STTH60L06C 80A diodes @ ~$2ea, even though it may end up costing a
tad more.
-Ian
On 25/06/2007, at 10:10 PM, Lee Hart wrote:
Ian Hooper wrote:
Out of interest, I'm building a motor speed controller at present
and I will have to agree that it can be done quite a lot cheaper
than the price of the Curtis units. They are a 20 year old design
now, and semiconductor technology (both transistors and
microcontrollers) has improved quite a lot in the last few
decades. e.g you can now get individual MOSFETs with about 1/10th
the on-resistance of those used in the Curtis controllers.
Really? A Curtis 1221 controller's power section has 32 220uf
200vdc electrolytic capacitors, 36 BUZ30A 200v 21a 0.1 ohm MOSFETs,
and 12 200v 40a SR4180R-C diodes. Look up the prices, and add up
the cost. Now tell me what you would use in their place that's any
cheaper.
--
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 ---
this is not as silly a question as it sounds. Here in Santa Barbara we have BEV rubber-tired trolleys that run up and
down the main street. ( oh yeah they are very popular with the tourists- a great success) They had to retrofit them with
a noisemaker, precisely because people were stepping off the curb right in front of them. I myself have been startled to
find one inches away, even with the sound device. They make a low whine, I can find out more if anybody cares.
JF
Garret Maki wrote:
I think it is a terrible idea. Attentive pedestrians are the answer, not noise
pollution.
-Garret
Thinking about the pedestrians that don´t hear an EV coming, i was wondering if
it´s possible to install the vroombox in an EV.
--- End Message ---
--- Begin Message ---
Dan,
You're not asking for a meatloaf recipe. To be frank, you're naivete
in the area of power electronics (1) leads you to believe that
controllers should be much cheaper than they really are.
I'm personally developing a MOSFET based controller for my own use, but
I am documenting my progress (nuancesystems.net). Right now, there
isn't much there, but when I have a barely-working prototype up, I'll
post more information than you can shake a stick at.
Having said that, I've done many _MANY_ hours of research, and put many
hours into my shop (garage) measuring, cutting, drilling, mounting,
testing, etc. I've also put a lot of $$$ into it, and I'm realizing
that while a lot of that money is a good investment (tools, etc), there
are a lot of failed experiments that lead ... nowhere. And that's just
for the mechanical layout.
The task you're speaking of is not a 60 minute job. You _will_not_
find a "simple and practical" design for a 320KW controller.
With regard to "help out a little bit," it's a bit like asking a doctor
how to cure a rash, and getting upset that he doesn't teach you
everything he learned in medical school. Even if he were willing to do
so, it would take too much time, and there's no chance you'll be a
doctor when he's done.
(1) You seemed surprised to learn that the transistor current rating is
often derated to 40% or less. Guess what? Your transistor budget
nearly tripled just now. Don't forget diodes, capacitors, bus bars,
good control and protection electronics, heat sinks, etc. A controller
is so much more than the cost of the transistors alone. Heck, I'd
personally rather get a good look at Otmars microcontroller code -- it's
at _least_ as important as the devices used or their layout. It's a
little strange you haven't asked about it, unless you don't really know
it's value. Which is exactly my point.
Complex problems often need complex solutions, despite belief to the
contrary.
Dan Frederiksen wrote:
I feel the same way. a cheaper controller certainly can be done. a lot
cheaper
a sub 500$ zilla1k equivalent if someone foxconn'ed it (mainstream
mass production, not typical b2b pricing mentality)
unfortunately those with experience don't want to take the 60 minutes
it takes for them to design a simple practical circuit to this effect
so others have to do the much greater task of getting training and
experience first and then doing it
some few will help out a little bit if asked about something isolated
but most here will rather fight it
Dan
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--- Lee Hart <[EMAIL PROTECTED]> wrote:
<snip>
>
> Not much. The L91 and X91 are basically the same
> motor, wound for
> different voltages. Since ADC only puts one wire in
> each slot, the X91
> has more slots to get more turns in (and more
> commutator bars to connect
> these extra wires to).
Hey Lee,
Those slots have 2 wires in them, don't they?
Jeff
____________________________________________________________________________________
Expecting? Get great news right away with email Auto-Check.
Try the Yahoo! Mail Beta.
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I would get 373 miles with my electric pickup truck if I drove around on a
level track at 15 mph for 25 hours. (maybe 150 to be honest)
Granted, the Sunrise is AC, had good batteries, is/was extremely efficient.
But alas, as I heard the rumour, it was driven very slowly on the range
testing track for hours upon hours. I hope he had good audio books to
listen to.
The following year, the Tour de Sol put a time limit on the range event and
made the range event drive on real roads at real speeds.
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I've gotten about 60 miles on a single charge on a factory 4 seater
GEM...... going about 12mph and barely touching the accelerator....
and that was going in circles and trying to never slow down or stop.
For more real world driving, 25 miles is more realistic from them.
Z
On 6/25/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
I would get 373 miles with my electric pickup truck if I drove around on a
level track at 15 mph for 25 hours. (maybe 150 to be honest)
Granted, the Sunrise is AC, had good batteries, is/was extremely efficient.
But alas, as I heard the rumour, it was driven very slowly on the range
testing track for hours upon hours. I hope he had good audio books to
listen to.
The following year, the Tour de Sol put a time limit on the range event and
made the range event drive on real roads at real speeds.
--
Zeke Yewdall
Chief Electrical Engineer
Sunflower Solar, A NewPoint Energy Company
Cell: 720.352.2508
Office: 303.459.0177
FAX documents to: 720.269.1240
[EMAIL PROTECTED]
www.cosunflower.com
CoSEIA Certified
Certified BP Solar Installer
National Association of Home Builders
Quotable Quote
"In the dark of the moon, in flying snow,
in the dead of winter, war spreading,
families dying, the world in danger,
I walk the rocky hillside
sowing clover."
Wendell Berry
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In the HP equation ( see below) I left in a "divide by" sign in error:
From: "Phil Marino" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: 55 MPH Part III
Date: Mon, 25 Jun 2007 12:06:28 -0400
Hi, Peter
I agree with your conclusions, and this is a good explanation, but some of
your units along the way might be a bit confusing to others. I'll insert
some clarifying comments within your post. ( Well, I hope they're
clarifying)
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: 55 MPH Part II
Date: Mon, 25 Jun 2007 07:38:26 -0700 (MST)
>>From what I've been reading it takes about 60 ft/lbs of torque to
>> maintain
> an average vehicle at 55mph.
>
> Or around 5-10HP.
>
HP = torque x RPM
Although this idea is sound, there are no commonly used units that make the
above equation true.
It might be clearer to say the HP = C x torque x RPM, where C = 5252
HP/ft-lb/RPM, and torque is in ft-lb, This is the number you give a bit
later on. I'll show where that number comes from.
If the motor has the HP to maintain the speed, but the torque is low, that
just means that the RPM is too high. Gear the RPM down and the torque
goes up by the same factor.
I.e. 1 HP = 5252 ft/lbs per minute.
Strictly speaking, 1 HP = 550 ft-lb/s = 33000 ft-lb/minute Notice that
the units are ft-lb, and not ft/lb. ft/lb is a unit of compliance ( the
inverse of stiffness). Ft-lbs are units of energy, so ft-lb/minute are
units of power.
However, ft-lbs are also units of torque, and this works also (as it must):
If you are talking about rotational power, 1 HP = 33000 ft-lb/ (radian/min)
.
************************************
THIS SHOULD HAVE BEEN : 1 HP = 33000 ft-lb radian/min
************************************
This is true because radians are dimensionless and have a value of 1. A
radian is that angle where the swept curve equals the radius. It's about
57 degrees., and exactly equal to 180 degrees/ PI.
Most people understand - and use - RPM (revolutions per minute) rather than
radians/ minute, so, if you convert this equation ( based on 2 x PI
radians = 1 rev) you get your (correct ) equation. (33000 / 6.28 = 5252.
Or. almost. It would be closer with a better approximation of 2 PI.
And, so, you are correct in all of the following statements,.
That would either be 5252 ft/lbs of torque at 1 RPM, or 1 ft/lb of torque
at 5252 RPM or 100 ft/lbs of torque at 52.52 RPM
So let's say your vehicle requires 8hp to go 55mph and that this works out
to 60 ft/lbs of torque at 700 rpm wheels. Let's say your motor 8hp, but
it's at 10 ft/lbs of torque and 4200 RPM. What you need is a transmission
(belt drive, chain drive, gears, etc.) with a 6:1 reduction ratio. That
will reduce the RPM from 4200 to 700 and increase your torque from 10
ft/lbs to 60 ft/lbs.
8HP into the transmission, 8HP out. The universe is happy and everything
works out.
Phil Marino
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Hello Garret
If it is a smart controller it will not allow your batteries to be over
charged during regen. Have you tried running down the batteries to say 60% and
then try?
Don Blazer
In a message dated 6/25/2007 8:15:12 AM Pacific Daylight Time,
[EMAIL PROTECTED] writes:
Thanks a ton! This tells me I need to keep looking for the right
parameter to adjust and there is hope yet. I would assume state charge
shouldn't affect the amount of braking force, just not a good idea to
stuff energy into a full battery, but I assume the controller doesn't
stop one from trying.
-Garret
Keith wrote:
"Yes I had a similar set up on a trike and my regen would bring me to a
complete stop on a steep hill. I was running a 6:1 gear ratio an e-tec
and had the regen set to only 50%. the trike weithed about 250lbs and
so do I and it was like slamming on the brakes when I hit regen."
************************************** See what's free at http://www.aol.com.
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--- Begin Message ---
A friend sent this one to me:
"Just found a business in Ft. Mill, SC that is in the EV conversion
business."
http://www.wsoctv.com/video/10922069/index.html?source=
http://www.ampmobiles.com/
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Just thought you might want to know, another
CONTROLLER is to be entered into the market for EV'rs,
heres an excerpt from an email I just received:
"Also we are coming out with a higher voltage
controller later this year for road use. Thank you
for your interest in Alltrax motor controllers."
M. Barkley
www.texomaev.com
http://www.austinev.org/evalbum/1135
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So you know, the speed at which electrons are "moving" in the conductor
is a few millimeters per second.
What you probably refer to is the time electric (or electromagnetic
if AC) field propagation speed which makes electrons start moving -
that is at light speed. Therefore you see light few miles away goes on
as soon as you flip remote switch despite actual electrons moving
few mm/sec. Not very accurate but obvious analogy is moving
water in a pipe - assuming water is not compressible (which is
almost he case), it can start flowing out of a mile long pipe
as soon as you start pumping it in in the other end, though the
rate of the water flow itself may be few inches per sec.
Victor
p.s. Without digging too deep, electrons themselves are not moving
anywhere - their charge get carried from one to another and charge
has no mass. If electrons were to move, the mass of conductor would
have measurable weight change (you can cram in more than you take out
but no one was able to detect any weight difference between "charged"
and neutral conductor), not to mention that material itself would
become different - copper with "lost" valence electrons is no longer
really a copper...
Mike Willmon wrote:
To be technically correct electrons flow the same speed in a particular medium,
which is some relatively high percentage of the
speed of light. Amps (or electrical current) is a measure of the amount of
electrons that flow past a certain point in 1 second.
More amps is more electrons per second
Joseph Tahbaz wrote:
What are amps? Well, amps are how quickly the electricity moves. More
amps, which means the electricity is moving faster, which means more
watts (power)
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Phil Marino wrote:
Although this idea is sound, there are no commonly used units that make
the above equation true.
It might be clearer to say the HP = C x torque x RPM, where C = 5252
HP/ft-lb/RPM, and torque is in ft-lb, This is the number you give a bit
later on. I'll show where that number comes from.
Power = Torque * rotation speed, period.
"C" is something you add when use different that metric units - it is
for your convenience, but not in definition of power.
It would be oh so much easier if everyone would just use metric units,
but we've gone through this before and as with everything, people stick
with what is more convenient to them.
Wonder if when ft*lb is mentioned why is it not also specified
if it's British lb or US lb. So much for the "convenient" system.
Victor
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At 09:21 AM 6/25/2007, bruce parmenter wrote:
...
Because the used EV market is so bone dry, my EV withdrawals
has me looking at what EVs 'are' available. Besides used GEM
nEVs, and new Zap's Xebra 40mph EVs, there really isn't any
EVs that are in the $15k range (sorry, no longer work for hp
which would give me my former income to afford a Tesla EV).
Used Sparrows are generally available for that or less.
(Yahoo SparrowEV group)
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
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I think noisemakers for evs are good for the transition period until the
public gets used to them.
Probably save yourself at least one collission lawsuit over a 20 yr
period.
On Mon, 25 Jun 2007 10:17 am, john fisher wrote:
this is not as silly a question as it sounds. Here in Santa Barbara we
have BEV rubber-tired trolleys that run up and down the main street. (
oh yeah they are very popular with the tourists- a great success) They
had to retrofit them with a noisemaker, precisely because people were
stepping off the curb right in front of them. I myself have been
startled to find one inches away, even with the sound device. They make
a low whine, I can find out more if anybody cares.
JF
Garret Maki wrote:
I think it is a terrible idea. Attentive pedestrians are the answer,
not noise pollution.
-Garret
Thinking about the pedestrians that don´t hear an EV coming, i was
wondering if it´s possible to install the vroombox in an EV.
www.GlobalBoiling.com for daily images about hurricanes, globalwarming
and the melting poles.
www.ElectricQuakes.com daily solar and earthquake images.
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