EV Digest 6871
Topics covered in this issue include:
1) Re: Troll Removal Survey
by "Peter VanDerWal" <[EMAIL PROTECTED]>
2) Re: Two
by "Peter VanDerWal" <[EMAIL PROTECTED]>
3) Re: Corded mower
by Tehben Dean <[EMAIL PROTECTED]>
4) Re: Tesla roadster motor philsophy AC vs. DC
by Tehben Dean <[EMAIL PROTECTED]>
5) thinking about cost
by Tehben Dean <[EMAIL PROTECTED]>
6) RE: Two
by "Phelps" <[EMAIL PROTECTED]>
7) Re: Doers vs talkers, was Otmar is getting rich?
by "Phelps" <[EMAIL PROTECTED]>
8) Re: EV count CT heard From. WARNING, CT DMV is anti-EV!
by Chip Gribben <[EMAIL PROTECTED]>
9) Re: full size truck conversion
by "Stuart Friedrich and Wendy Lyn" <[EMAIL PROTECTED]>
10) RE: Doers vs talkers, was Otmar is getting rich?
by "Dustin Stern" <[EMAIL PROTECTED]>
11) Re: Doers vs talkers, was Otmar is getting rich?
by "Roy LeMeur" <[EMAIL PROTECTED]>
12) Re: forget about acceleration... what about range?
by "Steven Arlint" <[EMAIL PROTECTED]>
13) Re: EV count CT heard From. WARNING, CT DMV is anti-EV!
by Dave Cover <[EMAIL PROTECTED]>
14) Is it just monday, or did the list size change?
by Jeff Shanab <[EMAIL PROTECTED]>
15) PODC video?
by Dave Cover <[EMAIL PROTECTED]>
16) RE: Chevy motor adapters
by Jeff Shanab <[EMAIL PROTECTED]>
17) Grass Roots charging infrastructure Was: Quick VEVCS poll
by "Richard Acuti" <[EMAIL PROTECTED]>
18) RE: Safety of inverter/controller or whole system?
by Jeff Shanab <[EMAIL PROTECTED]>
19) Re: Grass Roots charging infrastructure Was: Quick VEVCS poll
by Steve Peterson <[EMAIL PROTECTED]>
20) Re: Safety of inverter/controller or whole system?
by Lee Hart <[EMAIL PROTECTED]>
21) Re: Corded mower
by Lee Hart <[EMAIL PROTECTED]>
22) Re: Tesla roadster motor philosophy
by Lee Hart <[EMAIL PROTECTED]>
23) Re: Grass Roots charging infrastructure Was: Quick VEVCS poll
by "Brandon Kruger" <[EMAIL PROTECTED]>
--- Begin Message ---
Well this is true. If it really bothers you to have to ignore parts of
the digest, you could always create a new account (or use Gmail, hotmail,
etc.) and only check it once a day.
If someone wants to be an asshole and people ignore them, then eventually
they will go away and the problem will be solved. Either that, or they
will realize that they will get better results by being polite and people
will respond politely and again, the problem goes away.
> I use digest mode, and prefer digest mode. How do I block it?
> This doesn't remove the bandwidth to the list or the dark stain it puts
> into the archives.
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
> Well what I learned is school is that 1000 watts is a 1000 watts AC or DC
Yes but in this case, watts isn't the issue. AC current goes to zero
volts and zero amps 120 times per second, DC does not.
When you try to break a connection that has say 100 amps on it, it will
create an ARC. With AC the arcR goes out in 1/120 of a second when the
voltage goes to zero, with DC the votlage remains constant and the arc
stays on, this usually will weld the contacts together and then you CAN'T
break the circuit.
DC circuit breakers do things like use large gaps between the contacts to
make it harder to arc across, or they have a non-conductor that slides
between the contacts. Large current breakers also add things like
magnetic blow outs to pull the arc away from the contacts.
DC requires DC circuit breakers.
>
> Mitchell
>
> -------Original Message-------
>
> From: Brandon Kruger
> Date: 6/11/2007 3:56:54 PM
> To: ev@listproc.sjsu.edu
> Subject: Re: Two
>
> I thought AC and DC circuit breakers worked differently. A 100amp
> House circuit breaker may not work well in your EV.
>
>
> Brandon Kruger
> http://bmk789.dyndns.org/ev/
> http://cafepress.com/altfuel
>
> On 6/11/07, Phelps <[EMAIL PROTECTED]> wrote:
>> Have you thought about using 100 amp house circuit breakers?
>> In a electrical box
>>
> -----------------------------------------------------------------------------
>
>> ----------------------
>>
>>
>> Hey,
>> Being that I am inexperenced but maybe with enough knowledge to finally
>> answer a question more on my level...
>>
>> You can use switches to switch in batteries. They are called contactors
> when
>> used for such high amps. Similar to relays but heavier duty. You should
>> arrange and wire the batteries in a series/ parallel arrangement so that
>> theyare all discharging at 24, 48 and 96 volts, or whatever voltage you
> want
>> Older controllers were called contactor controllers. They mechanically
>> switched voltages, I imaging kinda like shifting gears. There is
> information
>> on the EVDL pertaining to their construction. I could send you past
>> posts
>> Ive saved. I plan to make a controller using a Parallax microcontroller.
>> Programmed to energize different contactors remotely placed at the
> batterry
>> pack depending on the position of my throttle potentiometer. (anyone
>> with
>> suggestions on this im open to suggestions).
>>
>> I think a cheap controller can be had from a junked golf cart? Some club
>> cars have a pretty decent sized controller and maybe you can get it
>> cheap.
>
>> Otherwise I think you are gonna spend atleast 500 dollars.
>>
>> Hope this helps.
>> Paul
>>
>> ________________________________
>>
>> From: [EMAIL PROTECTED] on behalf of Phelps
>> Sent: Mon 6/11/2007 2:28 PM
>> To: ev@listproc.sjsu.edu
>> Subject: Two
>>
>>
>>
>> Two simple questios..first..why use a controller.. Why not just 4 or 6
>> 100
>
>> Amp switches that add one more battery with every flick??
>>
>>
>>
>
>
> --
>
>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
I would recommend doing a battery powered mower. I think it would
work out better in the end not having to deal with a cord...
especially on a riding lawn mower. I just converted a string push
trimmer mower with a 24v scooter motor and 2 sealed motorcycle
batteries; it works really sweet.
Tehben
I have some ideas to deal with the cord. I was thinking about
using one
of those cord reel setups. We'll have to see how it holds up
reeling under
load. Or maybe a coiled cord affair with a mast on the mower and
elevated attach point on the house. The farthest point is around
200'+
from the plug.
I have almost an acre under grass and It will get kind of dicey
out on
the edge where about a 1/3 acre chunk has a dozen trees on it.
The main question that I have is: The current ICE motor on it is
a 19HP
Briggs. What HP electric motor do I need to replace that?
David
--- End Message ---
--- Begin Message ---
Thanks Peter. Finally someone has said something that actually makes
sense :^)... do others agree??
What hp ICE is equivalent to a 45kw motor ?
Tehben
On Jun 11, 2007, at 5:23 PM, Peter VanDerWal wrote:
You are absolutely right. Two systems that produce the same power
will
have about the same performance. Assuming they are built to about the
same standards, AC or DC will have about the same efficiency.
The commonly available AC systems are about 5%-10% more efficient
than the
commonly used DC systems, but there are DC systems readily
available that
are only 1-2% lower and that offer regen, but they cost about the same
(per kw) as the AC systems.
The really big advantage (IMHO) is that brushless systems don't create
brush dust, so the motors can last longer without maintenance.
John has stacked the deck a bit, however, because he was comparing
45kw AC
systems to a 500+ kw DC system. Obviously if you have 10 times the
power
you will have better performance.
At the moment there aren't any remotely affordable 500kw AC systems
so the
performance advantage currently goes to the DC systems
Ok. so I have a question for John and Victor (and anyone who wants)
Can we compare say 2 45kw motors and their controllers. One AC and
the other DC.
What are the hp and torque at what rpms and what is the efficiency of
the controller and motor.
Forget about cost.
The argument that a DC motor is more powerful doesn't make sense to
me if the 2 motors are the same hp/whatever. If it requires lower
gearing that does not mean it is not going to have the same
performance or torque in the end????
Tehben
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do
whatever I
wish with the message. By posting the message you agree that your
long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
With all the talk of AC vs. DC and people complaining about the price
of AC I was just thinking about the cost(money) of building an
electric car. when you think about how much people spend on a new
vehicle, often $30k, $40k or even $50k spending $15k(for an AC system
(of course I would like it to be lower)) on components really isn't
that much. Granted, the car is most likely not brand new and you
can't drive from coast to coast without stopping. But you are getting
a state of the art electric car!( minus state of the art batteries)
heck, your doing this for environmental reasons... right? so
recycling a used car is great and who needs to drive across the
continent 8)
I am just trying to say that an AC system is not really that
expensive considering how much people pay for a new vehicle....
thoughts??
Tehben
--- End Message ---
--- Begin Message ---
Lets do the math on that then
If 5A and 250 volt is equal to 2A and 32 V
Then 100 amp at 250 V would convert to a
32V and 40 amp well I guess that's not enough,, but it is a thought
-------Original Message-------
From: Dale Ulan
Date: 6/11/2007 5:59:33 PM
To: ev@listproc.sjsu.edu
Subject: RE: Two
>Well what I learned is school is that 1000 watts is a 1000 watts AC or DC
>>I thought AC and DC circuit breakers worked differently. A 100amp
>>House circuit breaker may not work well in your EV.
A DC arc will continue till the battery is dead or the breaker burns
Up physically. Not good. AC breakers rely on zero-crossing of
The current 120 times per second (or 100 times per second in Europe)
To extinguish the arc. You need special breakers for DC. Even look at
The voltage ratings of a switch. It is common to see a toggle switch
Rated for 5A, 250VAC and 2A, 32V DC. There's a reason for that.
-Dale
--- End Message ---
--- Begin Message ---
Otmar schematic
Yes please share ..
Thanks Mitchell
-------Original Message-------
From: Lawrence Rhodes
Date: 6/11/2007 6:42:48 PM
To: Electric Vehicle Discussion List
Cc: Dan Frederiksen
Subject: Re: Doers vs talkers, was Otmar is getting rich?
It just so happens that Otmar has a schematic of a Curtis controller
Somewhere. I'm not EVen sure if it's complete but it's the most complete
One I know of that you can have for free. Reverse engineer a Curtis?
Many people have done it. It's a good basic design. Lawrnece Rhodes....
----- Original Message -----
From: "Dan Frederiksen" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, June 11, 2007 10:16 AM
Subject: Re: Doers vs talkers, was Otmar is getting rich?
> Dustin Stern wrote:
> > Too me, what you are suggesting we do is kind of like when Hitler
Suggested everyone but blue eyed blonde's should killed.
> I want to make an open source controller design so we can get rid of the
> polution that kills the world and to that end I'm curious about how the
> zilla is built and that makes me Hitler?
> further, Otmar reversed engineered a Curtis
>
--- End Message ---
--- Begin Message ---
Egaddss Dave, what a run around. I hope you can get your car
registered. It's a nice piece of work. It sure handled great at the
PODC.
I can feel your pain. We had a fellow get the run around in MD and
finally gave up and sent the car down to his son in FL where it
passed with flying colors. FL appears to be somewhat liberal when it
comes to registering EVs.
The Maryland State Police is now inspecting EV Conversions here. The
police sargent "personally" drove that fellow's car to a weigh
station and flunked it because it was over the Gross Vehicle Weight.
Well, that's no surprise with it loaded down with flooded batteries.
So converting a flooded lead acid car in Maryland is going to be a
hassle. The only work around we can think of is to take a few of the
batteries out before it gets weighed. Hopefully they won't do a range
test. Or like you mentioned have the car inspected before the
conversion.
It sounds like this is going to continue to be a problem. If we are
stuck with lead the issues will be the car will be too heavy if we
use flooded batteries but if we go with AGMs the range may be an
issue if they require a 35 to 40 mile range test.
I guess we need to know the requirements before doing the conversions.
Chip
On Jun 11, 2007, at 7:54 PM, Electric Vehicle Discussion List wrote:
From: Dave Cover <[EMAIL PROTECTED]>
Date: June 11, 2007 7:35:11 PM EDT
To: ev@listproc.sjsu.edu
Subject: Re: EV count CT heard From. WARNING, CT DMV is anti-EV!
--- Bob Rice <[EMAIL PROTECTED]> wrote:
Dave Cover; Porsche 944 with BB-600 nicads. He made his debut at
Pof DC.
It's not a new tale, but I've been going through hell trying to get
my car registered. It's been
almost two weeks since I first went in to get my car registered and
I'm still no closer. In fact,
if I have to go through a mechanical inspection, it could be three
of four weeks before I can get
a scheduled appointment. And they won't/can't tell you what they're
looking for. I left my name
and number with at least 5 people before I got a call back. One guy
finally found a document
outlining EV specs writen in 1994.
Here are some of the requirements;
- Must be able to start and climb a 20% grade, forward or backwards.
- Must be able to maintain 15.5 mph on a 10% grade.
- Must be able to drive at 49.7 mph for 5 minutes.
- Must have a range of 34 miles.
- Must have a charger capable of recharging within 10 hours.
- Must be able to sit anywhere from -13 to 122 degrees F for 8
hours and then start and run.
- Must have contrasting color power leads.
- Must have ventilated battery enclosures that will keep the
hydrogen levels below 4%.
- Etc., etc.
They don't know what to do with EVs, and I'm having lot's of fun
educating them. As I'm talking to
this guy he's saying we have to make sure the motor doesn't stick
on and run into a mall and kill
somebody. I try to explain about my purpose built (Zilla)
controller and all of it's safety
features, but he doesn't want to hear it. Too many preconceived
notions out there.
The main problem is that I bought the car from out of state and I'm
registering it as an electric
car. If you register it before the conversion, no problem. Bob Rice
got his done without a hitch.
IF ANYONE IS CONSIDERING AN EV IN CONNECTICUT, REGISTER IT FIRST,
THEN CONVERT IT!
My sad story is not over yet. I'll keep you posted.
By the way, Fortunat Mueller posted about his experience a few
years ago and how the emissions
inspector came to his house for the inspection. That was the only
thing that went right for me.
Walt Bertotti works for the emissions dept out of Cheshire. He will
come to your house and certify
that your car is no longer a gasser and doesn't need emission
testing. You can call him at
203-271-5410, or the DMV Emissions Division at 203-805-6243. These
people were very helpful. Funny
thing is, one of the first people at DMV I spoke with said the
Cheshire office was shut down two
years ago and they no longer go out and do inspections. I guess
nobody told Walt that. Sigh.
Dave Cover
PS Anyone know a corrupt politician I can pay off? It might be
easier that way.
--- End Message ---
--- Begin Message ---
I've run the numbers on all pickups that could handle 4 passengers and came
to the same conclusion, especially if you want to stay legally within the
GVWR including all passengers. You just can't get a decent range.
Lots of folks here are in to drag racing, but another application that I've
thought about and would be cool to show off what EVs can do would be a 4x4
truck specifically designed for truck pulls. Here the extra weight in the
truck actually helps. I can't recall what weight classes are available for
4x4 trucks. Think of what a 4x4 could do with two separate 11" motors
coupled to separate clutchless transmissions feeding each differential. A
pull usually only lasts 15-20 seconds, so as long as the batteries can
handle the current and provide the needed voltage, energy density is not an
issue. Not a practical vehicle for driving around, but good for showing the
rural folks what EVs are about.
Stuart
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: ev@listproc.sjsu.edu
Subject: Re: full size truck conversion
Date: Mon, 11 Jun 2007 17:52:16 -0700 (MST)
Ok, we'll ignore all of the reasons that large trucks make REALLY poor
conversion candidates and answer your questions.
First, even though you didn't ask, I believe your weight estimate is
wrong. You didn't mention which type of battery, but common 6V golf cart
batteries weigh about 61-63 lbs each, it takes 24 of them for 144V, so
each string will weigh almost 1500 lbs, if you could manage to stuff three
strings in, they would weigh close to 4500 lbs and that doesn't count the
weight of the cables and battery boxes.
They are also rather large, so you will end up having to put some in the
bed. The engine bay is going to be pretty full with couple large electric
motors and one or two controllers, plus you'll probably end up mounting
one or two chargers in there.
If you already have the truck, you can figure this out yourself, each GC
battery is about 10.5" L x 7.2" W x 11.2" H. Make a model out of carboard
or foam and try seeing how many you can fit into a given area.
FWIW just sitting on the ground they will fill up an area a bit of 5 feet
wide by 8 feet long.
Second, you don't want to switch each bank in one at a time, you want to
wire all three strings together and use them all at once. This will give
you more range and the batteries will last longer.
Lead-Acid batteries produce more energy at low discharge rates than they
do at high discharger rates. By using all of the batteries at the same
time, each bank only sees 1/3 of the current needed to move the vehicle.
Batteries are sort of like people. A person in good shape could walk
50-60 miles before getting tired, but they might only be able to jog 10-15
miles before getting tired and only be able to run flat out for a mile or
so. So by reducing the load on the batteries to 1/3 they will last 4-5
times as long.
By my calculations, if you use each string individually you will end up
with about 25-30 miles of range, but by using them all at the same time
youll get 40-50 miles of range (at about 45 mph)
Also, this is a big truck with a lot of weight, that's going to take a lot
of current. If each string has to handle all this current by itself, then
the batteries will wear out in less than a year. By sharing the load you
should get two or maybe even three years out of the pack. Granted to even
consider this project you have to be fairly well off, but even so you
probably dont want to be spending $5,000-$6,000 on batteries every year.
You'll want to keep the transmission otherwise you won't be able to climb
any but the mildest hills and acceleration will be terminally slow. Think
zero to 60 times in the minutes not seconds.
How did you come up with 1,600 lbs for the motor and transmission? A
modern V8 weighs about 550 lbs and the transmission probably weighs 150
lbs. I think you're are off by about 1,000 lbs.
With fuel tank, radiator, etc, you will drop about 1,000 lbs total and add
4500 lbs of batteries, 300+ lbs of electric motors and probably another
700 lbs of cables, lugs, controllers, chargers, battery racks, etc.
I get the finished weight of the vehicle at around 10,500 lbs or roughly
2,000 lbs over the GVWR (without even adding the driver or cargo), so you
are going to need to beef up the suspension.
You could drop to only two strings of batteries, that will bring you
closer to the GVWR and you won't loose bed space to batteries. But your
range will drop from 40-50 miles to about 30 or so.
I'd estimate a conversion cost of about $20,000 to $25,000. You could
maybe knock off $5,000 or so, if you built it to have a top speed of only
35 mph. This will also extend your range a bit, maybe another 5-10 miles
Good luck.
>
>
> anyone ever actually complete the conversion on a full size truck?
> I know there were a couple in the making, but have never seen one
actually
> completed.
> what were the results?
>
> Any tips or pointers to convert a fullsize dodge 2500 4X4?
>
> I know, I know, the 4X4 is not the best for a conversion, but I regularly
> drive through the dirt on jobsites, and the clearace (and 4X4) is really
> handy.
>
> I know it will carry the battery weight without a problem, when I got the
> truck, the only thing the bed was used for is signage, they are big
sheets
> of plastic, and sometimes wood, they are big, but they are not heavy.
>
> I was thinking of losing the engine, and transmission, and bolting the
> electric motor directly to the transfer case..
> the motorbay and under the bed will all be reserved for batteries.
>
> 3 or maybe 4 banks 144v each? or more? is this plausable? when one is
low,
> switch to the other and then the other? I am concerned about the
> additional
> weight of the batteries actually subtracting from the distance
> achieveable.
> I know each bank will end up weighing like 800 pounds, which is not much
> in
> the grand scheme of things, but 800X3=2,400 pounds. and 800X4=3,200
> pounds.
> and that is alot.. (the current motor and transmission weigh about 1,600
> and also subtracting the cooling systems, and exhaust, and fuel tank,
> pumps, etc, I think I can get it to a little over breakeven, but I know
> lighter is better for an EV)
>
> any help is appreciated
>
> thank
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
_________________________________________________________________
Windows Live Hotmail is the next generation of MSN Hotmail. Its fast,
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--- End Message ---
--- Begin Message ---
If I had known how easy it was to take what I said out of context I would
have though twice about it. Well, my mistake.
To recap what I think is an important point: I'm not comparing anyone to
Hitler. I am saying we as a collective group shouldn't tolerate what is
wrong. And I am also saying ripping off any intellectual sweat equity is
wrong. And while I'm not a fan of the Curtis controller, that goes for the
Curtis as well as the Zilla, unless Curtis has released it or the diagram is
of an ancient build that a reasonable person knows Curtis wouldn't care
about.
I like EVs. And I like the EV community. And this means I try to respect
it and not reverse engineer it. I ask for help, and appreciate all the free
advice I've been given. But that is freely given, and I'm not going to make
a product and undermine the community members doing it.
Dustin
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lawrence Rhodes
Sent: Monday, June 11, 2007 6:41 PM
To: Electric Vehicle Discussion List
Cc: Dan Frederiksen
Subject: Re: Doers vs talkers, was Otmar is getting rich?
It just so happens that Otmar has a schematic of a curtis controller
somewhere. I'm not EVen sure if it's complete but it's the most complete
one I know of that you can have for free. Reverse engineer a Curtis?
Many people have done it. It's a good basic design. Lawrnece Rhodes....
----- Original Message -----
From: "Dan Frederiksen" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, June 11, 2007 10:16 AM
Subject: Re: Doers vs talkers, was Otmar is getting rich?
> Dustin Stern wrote:
> > Too me, what you are suggesting we do is kind of like when Hitler
suggested everyone but blue eyed blonde's should killed.
> I want to make an open source controller design so we can get rid of the
> polution that kills the world and to that end I'm curious about how the
> zilla is built and that makes me hitler?
> further, Otmar reversed engineered a curtis
>
--- End Message ---
--- Begin Message ---
Otmar schematic
Yes please share ..
Thanks Mitchell
The Curtis schematic being discussed is available here:
http://cafeelectric.com/curtis/curtisschematic.pdf
Please also see the page it is linked to from here (no warranties as to
accuracy):
http://cafeelectric.com/curtis/index.html
Cafe Electric main page:
http://cafeelectric.com
~~~~~~
Roy LeMeur
_________________________________________________________________
Make every IM count. Download Messenger and join the im Initiative now.
Its free. http://im.live.com/messenger/im/home/?source=TAGHM_June07
--- End Message ---
--- Begin Message ---
Good Point!
Along with what I described, a "Bed-O-Batteries" will also get 120
miles of range. 40 T-105s is twice the typical perscription of
batteries. That is pretty cool.
Cheers,
Steven Arlint
-------------------------------------------------------------------------------------------------------
On 6/11/07, Mike Willmon <[EMAIL PROTECTED]> wrote:
Don't forget about the infamous "Red Beastie" which, alas, is no more:
http://www.austinev.org/evalbum/37
--- End Message ---
--- Begin Message ---
--- Chip Gribben <[EMAIL PROTECTED]> wrote:
> The only work around we can think of is to take a few of the
> batteries out before it gets weighed. Hopefully they won't do a range
> test. Or like you mentioned have the car inspected before the
> conversion.
>
This is one of my concerns too. I don't want to put any more cells in to keep
the weight down, but
I won't be able to make the range, if they test it. Damned if you do, damned if
you don't. And I'd
like to know how they are going to monitor the percentage of hydrogen in my
battery boxes when I'm
charging.
Dave Cover
--- End Message ---
--- Begin Message ---
I got what seemed like a bunch of smaller digests today, Did those
survey quantities take effect already?
--- End Message ---
--- Begin Message ---
I was a little pre-occupied during the autocross (and had not charged my
camcorder) and didn't get
any video of the racing. Besides the footage of the blue sparrow, has anyone
posted video from
Saturday?
Thanks
Dave Cover
--- End Message ---
--- Begin Message ---
My point to recommending a racing flywheel was not the "racing flywheel"
version of a stock flywheel, it was to take advantage of the standard
provided that allows using a racing clutch, thus getting away from the
GM or FORD specific clutch.
--- End Message ---
--- Begin Message ---
Brandon,
I can't believe this didn't hit me earlier. This is a great idea! You can't
just build a gas station anywhere, you can't just brew and sell gasoline out
of your own home, but you damn sure can allow people to plug in at your
house either for free or for a reasonable fee to offset the costs and (for
now) I don't think there's any kind of law against it. We really -don't-
have to wait for the government or corporations to catch up with us. This is
something we can do right now.
Granted, my wife would get pissed if there were a line of strangers in front
of my townhouse waiting to plug in at all hours of the day and night but we
are definitely willing to contribute.
Brandon, in this database there should be a key or legend which shows the
limitations of the contributing "station". Color codes could be used to
show day/time restrictions, "pay" or "free", residential home or business,
that sort of thing.
I swear I'm going to design and patent coin-operated charging stations, 110
and 220v. Maybe 60 amps max. Like a parking meter, money goes in, breaker
closes and the timer runs. When the timer runs out, the breaker opens. Since
they're coin operated there's no need to run phone lines everywhere for
credit card swiping machines. You could sell these to any home or business
owner who wants to be an EV fuel station. No environmental licensing, no EPA
permits, no hassle.
This thread has opened up so many ideas. What do you guys think?
Rich A.
Message-ID: <[EMAIL PROTECTED]>
Date: Mon, 11 Jun 2007 12:51:41 -0500
From: "Brandon Kruger" <[EMAIL PROTECTED]>
To: "EV list" <ev@listproc.sjsu.edu>
Subject: Quick VEVCS poll
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Good afternoon everyone,
Before I get too into developing this charging station database,
I thought I'd take a survey to see how many people would actually
volunteer their charger/120/240 outlet to an EV driver in the area.
Please take a second to complete this poll.
http://bmk789.dyndns.org/ev/?p=16
Thank you,
Brandon Kruger
http://bmk789.dyndns.org/ev/
http://cafepress.com/altfuel
_________________________________________________________________
PC Magazines 2007 editors choice for best Web mailaward-winning Windows
Live Hotmail.
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_pcmag_0507
--- End Message ---
--- Begin Message ---
Thanks Dale.
I was doing some research and found a lot of papers that indicate A
separate link voltage generally lowers efficiency, but there are cases
where it allows a much higher frequency on the primary converter and
less switching losses in the commutation. It is a repeatedly re-visited
design, especially with bidirectional Converters.
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On Mon, 2007-06-11 at 22:20 -0400, Richard Acuti wrote:
> I swear I'm going to design and patent coin-operated charging stations, 110
> and 220v. Maybe 60 amps max. Like a parking meter, money goes in, breaker
> closes and the timer runs.
You may not need to invent everything from scratch. In parts of Canada
(and maybe in colder parts of the US) there are parking meters with
electric outlets for block heaters; people plug in to keep their cars
from freezing solid when it's 40 below.
--Steve
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--- Begin Message ---
Victor Tikhonov wrote:
You must be pretending that don't understand what I'm talking about.
No; not at all. I think the problem stems from confusing the special
case with the general case.
a. My AC drive cannot fail on. Therefore *NO* AC drive can fail on.
b. Your DC drive can fail on. Therefore *ALL* DC drives can fail on.
Both are examples of flawed logic. The "therefore..." part does not follow.
Let's make as much as possible equal. Remove fuses, contactors, all that
stuff normally *in the system* but outside controller since we discuss
whether AC *controller itself* is inherently safer since doesn't
have to rely on that external stuff or not.
OK. Let's compare some typical controllers. As you suggest, we will
assume there are no fuses, circuit breakers, contactors, or other safety
devices.
First, consider a normal DC PWM controller like the Curtis. It has one
switch and one diode. A "catastrophic failure" would be to short the
battery, short the motor (uncontrolled braking), or short the motor to
the battery (uncontrolled acceleration).
A single failure of either the diode or the switch will cause a
catastrophic failure. Let's assume each part has a failure rate of 1 per
10,000 hours; then the overall reliability is 10,000 hours / 2 failures
= 5000 hour MTBF (Mean Time Between Failures). If you drive 1 hour a
day, the odds are that such a failure would happen every 13 years.
Now let's consider a typical 3-phase AC controller. It has 6 switches
and 6 diodes; the diodes are in antiparallel with the switches, and the
switch+diode pairs are arranged in 3 groups of 2 in series. A
"catastrophic failure" would be to short the battery, or to apply
uncontrolled power to the motor (uncontrolled braking).
With this circuit, a single failure of any switch does not result in a
catastrophic condition. But if *two* switches fail, you get a
catastrophe; either a shorted battery or locked motor.
Let's assume each part has the same failure rate; 1 per 10,000 hours.
When it takes two failures, and the system quits working when the first
part fails (so you can't just keep going until the second failure
occurs), you multiply the failure rates. So the odds are that it will
take 100,000,000 hours before you get 2 specific parts to fail at the
same time.
But there are 66 combinations of the 12 parts failing 2 at a time. So
the overall reliability is 100,000,000 hours / 66 failures = 1,515,000
hour MTBF. That's a very long time! This AC system is about 300 times
less likely to have a catastrophic failure than the above DC system. Great!
But where did this extra reliability come from? Not from the AC vs. DC
motor; it all came from a controller design that had a second switch in
series with every failure path.
Now let's go back and consider a high-end DC controller that also has a
second switch in series with each failure path. In fact, it could be
exactly the same 3-phase AC controller, but with the AC motor replaced
by a series motor's armature and field.
Now you have a series motor controller with electronic reversing and
regen (and no contactors). Its reliability will be the same as it was
when driving the AC motor; a 1,515,000 hour MTBF. The controller's
software will have to be reprogrammed, of course.
Finally, we might realize that we don't need electronic switches for a
series motor controller with these features. They switch far less often,
so contactors can be used for most of them. For example, the 4
switches+diodes for reversing the field can be replaced with contactors,
leaving 2 electronic switches and diodes for the armature.
The key point for maintaining the high reliability against catastrophic
events is
1. Have at least TWO switches in series for every possible catastrophic
failure mode.
2. Include a control system to guarantee that the system will shut down
and refuse to operate as soon as *one* failure occurs.
These can be accomplished just as well for either an AC or a DC system.
In fact, the Zilla controller mentioned does include the logic to
operate a contactor in exactly such a manner. (The Curtis controllers do
not).
AC system technically doesn't need main contactors to kill the
battery to prevent runaways.
Then why do all AC drives include them?
Not all. Swiss version of Smart with TIM400 AC system with Zebra
battery doesn't have contactors. (well sort of, battery contains
emergency contactors inside).
I am honestly unaware of any system, AC or DC (other than homebuilt
systems made by amateurs) that does not include some form of contactor,
circuit breaker, or other emergency shutdown device. I don't think a
conscientious designer can leave them out, because there is always that
chance of a double failure causing a catastrophe that kills somebody. No
matter how unlikely, it might still be caused by an accident, or
assembly error, or incompetent mechanic, or other unforseen event.
All I'm saying AC system's designer doesn't have to worry about
AC motor running away because main contactors get stuck while
power stage fails. DC system's designer has to.
No; but he has different failure modes to worry about that are just as
catastrophic (locking the front wheels at 70 mph, setting fire to the
batteries...)
Locking the rotor sudden stopping may be dangerous but by far
is not as bad as runaway car.
Are you sure? A runaway car can normally be stopped with the brakes.
What do you do when the front wheels lock at speed?
At least you're not moving in a few seconds. With runaway DC system
you are moving for many seconds until something nastier happens.
That depend on what the backup system is, and how long it takes to respond.
Again, don't bring into equation safety hardware outside controller.
It is there precisely because controller itself does not possess ability
to be as safe as AC inverter without those.
Here again, it depends on the controller. The Curtis doesn't have it "in
the box". The Zilla does.
I'm more than certain you will come up with some explanation rather
than just admit without arguing this particular advantage of AC :-)
Victor, I'm just trying to say the safety advantage comes from the extra
sophistication of the controller; not from any fundamental advantages of
AC vs. DC.
--
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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Zeke Yewdall wrote:
You are looking at at least a 5 or 7 HP electric motor I'd bet. That
means 240vac, 40A circuit or more -- not a regular extension cord. If
you use a regular AC induction motor, it also tends to overheat under
voltage drop -- so a 200 foot cord is bad news.
A GE Electrak electric garden tractor only uses about 100a at 36v while
mowing with a 3-motor mowing deck; that's 3600 watts to move an 800 lbs
tractor. A little riding mower is going to be even less. So, a corded
unit is not out of the question.
You could probably do it from a 120vac 15amp outlet if that's all you
had plugged into it. The main issue to me would be avoiding the cord.
When I used corded mowers, I had to work out a pattern so the cord
automatically stayed out of my way as I mowed.
--
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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Jeff Major wrote:
A properly designed sepex motor/control will be able to get you the
same torque as the series motor. I use a Sevcon control and D&D
SepEx at 48 volts. Current limit is 400 amps. Normal field current
is about 5 amps. Max field is 35 amps. So I am pretty sure I will
get enough field at current limit to equal what a series
motor/control would do.
If normal field is 5 amps and max is 35 amps, you can overdrive the
field by 7:1 (5a x 7 = 35a). That's pretty good! A 4:1 ratio seems to be
more typical.
To see how this compares to a series motor, we'd have to know what frame
size sepex motor you have, and get the data for an equivalent series
motor. For example a 3.5hp (~3.5kw) golf cart motor would draw about 73
amps at 48v. With a 400 amp controller, you'd be overdriving its field
by 400a/73a = 5.5:1.
On the other hand, a Zilla controller can deliver 2000 amps, driving a
9" series motor rated at 175 amps, can overdrive the field by 2000a/175a
= 11.4:1.
Now, if you have a drag race set up with current limit at 1000 (or
2000) amps, then you'd have to have a sepex field with a lower
resistance so you could overexcite it even further. This is
possible, but your field control bridge would have to be beefier.
Right! For racing or high performance applications, the series setup is
better. But for daily driving, I think a sepex setup has a lot to offer.
It can be built to produce "enough" torque, as well as making
regenerative braking practical.
With the sepex motor you do lose the series field inductance in the
armature circuit. So the armature controller has to deal with that.
Yes. For example, the Soleq EVs had sepex DC motors. They had two big
series inductors (in parallel) in the armature circuit, to make up for
the missing series field inductance.
And I do not agree with Lee when he says that induction motors make
poor generators. When you have a induction motor and control for a
vehicle, you will need torque control. I have found this means using
closed loop flux vector control. This type of control decouples the
direct and quadrature current components, similar to separately
exciting the field. This gives great generator performance from the
induction motor.
I think we are saying the same thing. I meant that an induction motor
*by itself* is a poor generator. Like a series DC motor, it is hard to
use as a generator, because there is no direct way to control it.
But, with a sufficiently complicated controller, you can make it work.
Even so, induction generator (or series DC generator) are among the
least efficient types. PM, wound rotor AC (alternators), and shunt DC
(generators) can beat them.
I routinely see higher regeneration power than motor power in our
hybrids. If fact, my opinion is that the system is better at
generating than motoring because it can maintain higher motor
voltage.
Make some measurements to know for sure. Note that peak power while
generating is not an indication of its efficiency. It may simply be that
the controller's diodes have lower voltage drops than its IGBTs, so the
*controller* can handle more regen current than motoring current.
--
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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Hi,
Thanks for the positive feedback. My current idea is to make
commercial (business-owned) charging stations red points and volunteer
stations blue, as you can see in the alpha on my website. When you
click a point on the map, it gives detailed information. For
commercial stations this would include business name, address, number
and type of chargers, and whether or not the charger is down. For
volunteer stations, I would include contact information of the host,
as well as address and number/type of charger(s). I list all
commercial stations from the EV Charger News website, and link each
point to its respective page on EVCN. Volunteer stations would be
submitted through a form on my website, and I would contact the host
via email to confirm the site before listing it on the map. Do you
think any of this should be done differently? I'm open to
suggestions.
About the standalone pay charger, I think this could be done fairly
easily if I could get some kind of weatherproof housing similar to a
parking meter to house the hardware in. I believe these stations
could be hand-built for $500 each at the absolute most. Future
versions could include credit card scanners, or an internet connection
to bill to an account that would be controlled via the web. Lots of
potential for these devices.
Thanks again,
--
Brandon Kruger
http://bmk789.dyndns.org/ev/
http://cafepress.com/altfuel
On 6/11/07, Richard Acuti <[EMAIL PROTECTED]> wrote:
Brandon,
I can't believe this didn't hit me earlier. This is a great idea! You can't
just build a gas station anywhere, you can't just brew and sell gasoline out
of your own home, but you damn sure can allow people to plug in at your
house either for free or for a reasonable fee to offset the costs and (for
now) I don't think there's any kind of law against it. We really -don't-
have to wait for the government or corporations to catch up with us. This is
something we can do right now.
Granted, my wife would get pissed if there were a line of strangers in front
of my townhouse waiting to plug in at all hours of the day and night but we
are definitely willing to contribute.
Brandon, in this database there should be a key or legend which shows the
limitations of the contributing "station". Color codes could be used to
show day/time restrictions, "pay" or "free", residential home or business,
that sort of thing.
I swear I'm going to design and patent coin-operated charging stations, 110
and 220v. Maybe 60 amps max. Like a parking meter, money goes in, breaker
closes and the timer runs. When the timer runs out, the breaker opens. Since
they're coin operated there's no need to run phone lines everywhere for
credit card swiping machines. You could sell these to any home or business
owner who wants to be an EV fuel station. No environmental licensing, no EPA
permits, no hassle.
This thread has opened up so many ideas. What do you guys think?
Rich A.
Message-ID: <[EMAIL PROTECTED]>
Date: Mon, 11 Jun 2007 12:51:41 -0500
From: "Brandon Kruger" <[EMAIL PROTECTED]>
To: "EV list" <ev@listproc.sjsu.edu>
Subject: Quick VEVCS poll
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Good afternoon everyone,
Before I get too into developing this charging station database,
I thought I'd take a survey to see how many people would actually
volunteer their charger/120/240 outlet to an EV driver in the area.
Please take a second to complete this poll.
http://bmk789.dyndns.org/ev/?p=16
Thank you,
Brandon Kruger
http://bmk789.dyndns.org/ev/
http://cafepress.com/altfuel
_________________________________________________________________
PC Magazine's 2007 editors' choice for best Web mail—award-winning Windows
Live Hotmail.
http://imagine-windowslive.com/hotmail/?locale=en-us&ocid=TXT_TAGHM_migration_HM_mini_pcmag_0507
--- End Message ---
