EV Digest 5345
Topics covered in this issue include:
1) Re: Thermal measurements
by "Roland Wiench" <[EMAIL PROTECTED]>
2) Re: Prius plug in over in England
by Lee Hart <[EMAIL PROTECTED]>
3) DC safety circuit
by "Michaela Merz" <[EMAIL PROTECTED]>
4) Re: Prius plug in over in England
by Bob Bath <[EMAIL PROTECTED]>
5) TS Internal Resistance Testing
by "Bill Dennis" <[EMAIL PROTECTED]>
6) Re: Orb Carnage....
by Lee Hart <[EMAIL PROTECTED]>
7) how to : determine weight from photo .. weight of images for 3 square
yards ( 9 square feet) .. and car cutout .. same ratio as AREA's ratio
by "peekay" <[EMAIL PROTECTED]>
8) Re: NiCads (was: Greetings)
by "peekay" <[EMAIL PROTECTED]>
9) Re: A cleaner EV genset.
by [EMAIL PROTECTED]
10) Re: the $5000 car - could use some expert help
by "peekay" <[EMAIL PROTECTED]>
11) Re: DC safety circuit
by "David Roden" <[EMAIL PROTECTED]>
12) Coast--down method for aero drag
by Neon John <[EMAIL PROTECTED]>
13) Re: the $5000 car - could use some expert help
by "peekay" <[EMAIL PROTECTED]>
14) Re: Variable brush position for DC motor
by "peekay" <[EMAIL PROTECTED]>
15) Re: 3kw genset for $315
by [EMAIL PROTECTED]
16) Re: Crazy DC regen idea, thoughts, comments
by Lee Hart <[EMAIL PROTECTED]>
17) Re: 3kw genset for $315
by Neon John <[EMAIL PROTECTED]>
18) Re: Charging Dead Flat AGMs
by Lee Hart <[EMAIL PROTECTED]>
19) Re: how to : determine weight from photo .. weight of images for 3 square
yards ( 9 square feet) .. and car cutout .. same ratio as AREA's ratio
by Neon John <[EMAIL PROTECTED]>
20) Under the hood of the EV Buggy
by "Paul G." <[EMAIL PROTECTED]>
21) Re: DC safety circuit
by Nick Austin <[EMAIL PROTECTED]>
--- Begin Message ---
Mike,
The Link-10 wire length in my EV is a 25 foot of double shield No. 16 gage 5
pair (10 wires) stranded wire that each wire has a aluminum tape shield and
than a over all expanded aluminum shield under a plastic cable jacket.
This wire is design-for the Link-10 where each pair that twisted one turn
per foot through out its length.
My total length from the E-meter to a setscrew terminal block that is in the
equipment compartment next to the battery charger is 25 feet. The sensor
unit which I pick up from EV Parts has a 6 foot length of two wires that is
also jacket. This makes a total length of 30 feet for me.
Roland
----- Original Message -----
From: "Mike Phillips" <[EMAIL PROTECTED]>
To: "Roland Wiench" <ev@listproc.sjsu.edu>
Sent: Sunday, April 09, 2006 8:14 PM
Subject: Re: Thermal measurements
> Roland,
>
> Thanks so much for your information. I had forgotten that the Emeter
> has that capability. I'm not sure if it's optional or not. I'll see if
> mine can measure temperatures as well. Do you remember how long the
> temp probe cable was? Mine would have to route something like 10 feet
> or more to reach a battery. If it's a solid state device, the wires
> could be lengthened. If it's a thermocouple, then it can't.
>
> But in the mean time the Acurite stuff would work just fine for
> nailing down the thermal behavior of the pack. I wish the dolphin had
> a thermal measurement as well for the pack, then I could log it while
> driving/charging.
>
> I wish I had room for insulation. I will also have to look closely at
> ventilation as well for excess heat. I've got some serious research to do.
>
> Thanks again!
>
> Mike
>
>
>
>
> --- In [EMAIL PROTECTED], "Roland Wiench" <[EMAIL PROTECTED]> wrote:
> >
> > Hello Mike,
> >
> > To read my battery pack temperature on the go, I'm using a temperature
> > sensor that is design for the Link-10 E-meter.
> >
> > It is a two wire temperature sensor that connects to the No. 6 and
> No. 8
> > terminal strip on the back of the Link-10. The part No. for this
> sensor is
> > 1N2535.
> >
> > The sensor is bolted on any one of the battery post. The
> temperature prod
> > is imbedded in side a wire lug and isolated from any metal of the
> wire lug.
> > The wire lug is than either bolted to a extended battery post clamp
> or a
> > battery stud.
> >
> > This morning, in Great Falls, Montana, it was 40 degrees F. Inside my
> > garage the on wall temperature is 65 degrees F. I turn off the heating
> > system for the winter, but I have a super high R-factor insulation
> that is
> > 80 R's for the wall and 140 R's ceiling and a garage door of 20 R's,
> so it
> > maintains this temperature for a long time and even into the summer.
> >
> > The battery pack is also in a super insulated battery box, so even
> after
> > driving the EV, it will hold the battery temperature range from 62
> to 65
> > degrees.
> >
> > This morning when, the battery temperature was at 17 degrees C. or
> 62.6 F.
> > Driving for one mile at 50 battery amp, the temperature rose to 18
> degrees
> > C. or 64.4 F. After letting the EV set one hour in a outside ambient
> > temperature of 40 F. the Link 10 still had a read out of 18 C. It
> may be
> > between 17.5 and 18 C.
> >
> > This is with a 260 AH battery pack that weighs more than a ton. A
> smaller
> > pack at a lower AH will increase in temperature faster and lose the
> > temperature quicker.
> >
> > Driving home for another mile at 50 battery amp the battery temperature
> > still read 18 C. Letting the EV set for 20 hours, the temperature
> will be
> > down in the 17 C. range or about 62+ F.
> >
> > If you battery pack is un-insulated, then the battery post will be
> the same
> > temperature as the ambient air very quickly.
> >
> > To read the temperature on a Link-10, press F3 for a read out.
> >
> > Before I had a Link-10, I used a small battery operate temperature
> gage made
> > by ACURITE which you can get from WalMart. It has a 10 foot cable and
> > sensor, normally for reading outside temperature from inside you
> house. I
> > used many of these sensors, when I was building my high R-Factor
> house, for
> > testing the floor to ceiling and inside wall to outside ambient
> temperature.
> >
> > I normally keep my battery pack in about the 65 degree range all winter
> > long. In summer, the battery back temperature is between 70 and 75
> F. I do
> > not drive that far, so I do not have to squeeze every AH out it. I get
> > about 2000 cycles out of my batteries, because I at 80% capacity
> about 95%
> > of the time. For me this is about 100 cycles per year or would be
> 20 years.
> > I normally get 10 to 12 years out of a battery pack.
> >
> > Roland
> >
> >
> > ----- Original Message -----
> > From: "Mike Phillips" <[EMAIL PROTECTED]>
> > To: <[EMAIL PROTECTED]>
> > Sent: Sunday, April 09, 2006 11:30 AM
> > Subject: Thermal measurements
> >
> >
> > > Has anyone measured their battery temperatures? Just curious what you
> > > used and what numbers you got in various conditions.
> > >
> > > I'm secretly hoping for proven schematic with part numbers cause I'm
> > > buried right now.
> > >
> > > But even meat thermometers qualify to answer the question.
> > >
> > > Mike
> > >
> > >
> > >
> > > Here's to the crazy ones.
> > > The misfits.
> > > The rebels.
> > > The troublemakers.
> > > The round pegs in the square holes.
> > > The ones who see things differently
> > > The ones that change the world!!
> > >
> > > www.RotorDesign.com
> > >
> > >
> >
>
>
>
>
>
>
--- End Message ---
--- Begin Message ---
Mike Phillips wrote:
> The guys at CalCars.org did just that. 20ah AGM's. It worked pretty
> well. Now They are moving to Lithium I believe.
That's an example of what I meant; everyone I know of is going high-cost
lithiums.
> At the Maker Faire this month they are going to convert a Prius to a
> Plug in Prius right in front of everyone, then the owner drives it
> back to Washington/Oregon.
I wish I could see this. In particular, I'd like to know how they are
defeating the Prius's built-in battery state of charge controls and
alarms.
--
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 ---
Since I read about how bad DC controllers might fail (well, I kind of knew
that before but .. ) I was driving down the road with my foot on the
clutch. And I was thinking: It can't be too complicated to have some sort
of fail safe that would 'kick in' if a controller breaks down.
A micro switch on the potbox would have to be combined with a voltage
sensing circuit at the motor. If the foot is off the gas pedal and there's
still voltage supplied to the motor: Throw the contactor. If a circuit
would be able to distinguish between a PCM signal and a 'flat' DC (which
would be the case if the controller fails?) it would be able to kill main
power without any need to sense the gas- or brake pedals.
Now - I am no EE so I assume I must have mad some errors. Please help me
out and, maybe, even suggest a circuit design.
Thanks.
Michaela
--- End Message ---
--- Begin Message ---
Yes they have done this with both PbA and LiP . All I
know, is that it has something to do with CAN: like
that's the software that regulates the batteries, or
somesuch. I went on the wikipedia
http://www.eaa-phev.org/index.php?title=Prius_PHEV&rdfrom=http%3A%2F%2Fwww.seattleeva.org%2Findex.php%3Ftitle%3DEAA-PHEV%26redirect%3Dno
and am clearly missing something in there... Or at
least I was the last time I visited.
peace,
--- Lee Hart <[EMAIL PROTECTED]> wrote:
> Mike Phillips wrote:
> > The guys at CalCars.org did just that. 20ah AGM's.
> It worked pretty
> > well. Now They are moving to Lithium I believe.
>
> That's an example of what I meant; everyone I know
> of is going high-cost
> lithiums.
>
> > At the Maker Faire this month they are going to
> convert a Prius to a
> > Plug in Prius right in front of everyone, then the
> owner drives it
> > back to Washington/Oregon.
>
> I wish I could see this. In particular, I'd like to
> know how they are
> defeating the Prius's built-in battery state of
> charge controls and
> alarms.
> --
> 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
>
>
'92 Honda Civic sedan, 144V (video or DVD available)!
www.budget.net/~bbath/CivicWithACord.html
____
__/__|__\ __
=D-------/ - - \
'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering wheel?
Are you saving any gas for your kids?
__________________________________________________
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--- End Message ---
--- Begin Message ---
How do I test for the internal resistance of a ThunderSky cell? My first
attempt was to hook three cells in series, then connect them to the motor.
The OCV was 12V, and about 35A was being drawn when the circuit was
connected. I thought I would compare the voltage at 35A to the open circuit
voltage. But the voltage never stayed the same. It just kept dropping all
the time (about 1/100 volt every 10 seconds).
Do I need to test with a lower current, or is there some other method for
testing the resistance?
Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
Cor van de Water wrote:
> Keep It Simple: let the car be without power for this split second,
> even though it means switching under load. It will be hard to find
> reliable 200+ Amp diodes that can take the peak amps during switching
> (usually under the max load) and be affordable enough to parallel
> every battery. Besides, they do not add any functionality, only
> avoid burning the relay contacts during closing (bouncing).
The travel time between NO and NC contacts for a relay is on the order
of 1-2 msec. Look up the I(fsm) surge ratings for diodes; it is
typically 10-100 times the normal continuous duty rating. If you're
running a 500amp Curtis, a little MBR5025 (TO-220 case, 25v 50amp
Schottky) can handle it for 8 msec.
But I agree; it would be better to have a control system that cuts
current , then switches the relay, then resumes current. The diode is
just insurance, or a way that a control board at each battery can decide
on its own when to "cut and run", to avoid a tangle of wires and a
central controller.
The real problem with this system is not the diode, but the relay. Where
to find a 500amp SPDT relay that isn't so expensive that it makes the
method not worthwhile?
However, this system might work in small, low-power vehicles, where you
could use a little 12v 40amp automotive relay.
--
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 a very novel idea .. the only issue is getting a jeweller's scale
may i humble suggest :
cut a plywood sheet to match the paper size, paste the printout..
cut the car image out .. weighing is easier .. kitchen scale can be used
..peekay
----- Original Message -----
From: "Neon John" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, April 10, 2006 3:45 AM
Subject: frontal area
> On Sun, 9 Apr 2006 14:12:57 -0700 (PDT), David Dymaxion
> <[EMAIL PROTECTED]> wrote:
>
> >You do have to be careful. Some manufacturers want to make the Cd
> >sound as good as possible, so they'll just use the height*width of
> >the care for the area. I think one of the best sources for aero info
> >is <http://www.epa.gov/otaq/tcldata.htm>.
>
> Here's a very accurate method of measuring the frontal area of your
> car. It is a variation of the old scientist's trick called graphical
> integration, updated for the digital world.
>
> First, get 4 yard sticks or other known length objects and make a
> square. Position this square upright in front of the car.
>
> Take your digital camera, zoom it to maximum optical power and get
> back from the front of the car ever how far it takes to make the car
> fill most of the frame. Squat down or put the camera on a tripod so
> it is looking straight at the car at the level of its centerline.
>
> Snap the photo. Make two prints on as heavy a paper or cardboard as
> your printer will feed. Resolution or quality does not matter.
>
> You'll need some sort of small scale or balance. An electronic
> postage scale will work, as will a jeweler's scale (go to the jewelry
> store if you have to), as will those little scales sold in head shops
> for cutting dope :-)
>
> Take one print and very carefully cut out the square. If you used
> yard sticks, that square represents 9 sq feet. Weight the square.
> Divide the weight by the area (9 sq ft) to get the weight per square
> foot.
>
> Next, very carefully cut out the outline of the front of your car.
> Weight that cut-out. Divide the weight by the weight per square foot
> that you computed above. Viola! The result is the area of the
> frontal area in square feet.
>
> This is a very easy procedure and is amazingly accurate.
>
> Oh, the old scientist's trick? To integrate a curve, plot your data
> on graph paper. Weigh the graph paper with the border removed, if
> appropriate. Then cut out the curve along the X-axis and weight it.
> Some simple ratio math and you have your area under the curve.
>
> There is some freeware software out there that can compute the area of
> a designated data plot or image. I have it but I don't recall where
> it came from. Frankly, it's easier and faster to just cut out the
> shape and weigh it.
>
> John
>
>
> >If anyone would like to do coastdowns with their car, I have a
> >program that will calculate the rolling resistance and effective
> >area, I'd be happy to run the numbers.
>
> Why don't you make that program available to list members? I have one
> that I wrote a LONG time ago. It won't run under winders or else I'd
> make it available.
>
> It would be nice to have a program out there for everyone to use so
> that our computations would be identical.
>
> John
> ---
> John De Armond
> See my website for my current email address
> http://www.johngsbbq.com
> Cleveland, Occupied TN
> A foolish consistency is the hobgoblin of little minds.-Ralph Waldo
Emerson
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.385 / Virus Database: 268.4.0/305 - Release Date: 08/04/2006
>
>
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--- Begin Message ---
maybe toshiba's one year old battery which charges in one minute
flat .. to 80% .. developed into a model that will suit
..peekay
----- Original Message -----
From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, April 10, 2006 4:08 AM
Subject: NiCads (was: Greetings)
> I have the SAFT MRE-100's in my Wabbit. So far, so good.
>
> Water cooling is the way to go, but a pain to implement.
>
> If I had it to do all over again, I think I would buy super high
> quality rubber hose and drill just the right size holes in the side
> of it to push onto the barbs on the batteries. Maybe lube up the
> holes with RTV to be sure of a good seal.
>
> I may actually do it this way when I get tired of fixing
> leaky connections. :-)
>
> I bought these when the Euro was about equal to the dollar.
> That is no longer the case now. :-(
>
> Bill Dube'
>
> At 03:21 PM 4/9/2006, you wrote:
> >As many of you know, I kind of slipped out of the EV world (and
> >arguably out of any world) for the past two years. However, I'm
> >back, and I'm determined to install a NiCad or NiMH battery pack in
> >quantum mechanic.
> >
> >(alter ego sez: He just doesn't give up, does he folks)
> >
> >I'm currently in negotiations with SAFT, but if anyone has any other
> >suggestions for NiMH/NiCad, please let me know.
> >
> >My NiZn b
> >
> >Minimum requirements:
> >
> >55Ah
> >capable of sustained 100A/2C, bursting to 250A/5C
> >
> >I'm willing to install a water cooling system if that turns out to
> >be advisable.
> >
> >I will attempt to read this list regularly again. Sorry that I went
> >away.. bad things happened in my personal life.
> >
> >Sheer
> >
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.385 / Virus Database: 268.4.0/305 - Release Date: 08/04/2006
>
>
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--- Begin Message ---
> Peter and All,
> You have a valid point about propane conversions that aren't done
> correctly, but the conversion kit I mentioned in my original post comes
> with an oversized regulator that has an idle mixture adjustment, and a load
> block (needle and seat) assembly to adjust the mixture under load (url
> below). I should have mentioned this, but I sometimes forget that not all
> the people on this list are recovering gear-heads and could easily do a
> conversion themselves! So, in addition to my comment about "if you can't
> afford a diesel engine...", if you don't feel comfortable doing a propane
> conversion, then you could pay a certified company to do the conversion or
> buy a propane genny, if that's the route you want to take.
> BB
Is this kit propane-only, or can it be used with natural gas? I had read
somewhere of adapting a scuba tank (?) to act as a CNG container and getting
off-the-shelf components to adapt a gas-powered ICE. No, it doesn't sound safe
to me (I'm not a "gearhead"), but isn't CNG stored at 3000psi and need
specialized connectors for refueling?
--- End Message ---
--- Begin Message ---
i have been suggesting use of a very small diesel generator
running 24x7 to charge the batteries .. which have a
lot of oomph .. (see the Tandy .. rock sturdy, small,
quick, enormous torque, narrow, high, two seater..
uses a 9kw dc motor to power rear wheels)
but like timmi pointed out, leaving your generator
engine running unattended is agains the law
maybe the teeny weeny 2hp diesel generator could
be used to power the care wherever it is parked
and law is not broken
like at home.. in the garage .. thousands of honda,
lombardini 2hp, 1hp diesel gensets work ..
this is for areas which don't have electric power ..
camps, work sites, cottages for holidays, etc
at home, use the power socket !
in all cases .. carrying or not carrying the small
genset is an 'option' .. a cost which is not a cost ..
for MAKING the car .. it is an add on
EV's ARE the way to go .. battery, fuel cells ..
OR the new kid on the block .. EMB's
..peekay
----- Original Message -----
From: "Cor van de Water" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, April 10, 2006 2:33 AM
Subject: RE: the $5000 car - could use some expert help
> Timm,
>
> An EV would be interesting, but I read in your charter on this
> Yahoo group that you want to use a 2-stroke Diesel.
> To me that sounds like the wrong direction - you will increase
> pollution and be far worse than most new cars on the road today,
> so I urge you to re-think this path.
>
> Besides efficiency, there is a lot to gain in a clean car engine
> because a moped is efficient but nobody wants to run it indoors
> and even outdoors it can be bad.
> We have just been through this discussion in relation to use
> of a generator as range-extender for an EV.
> Incidental use may be beneficial, but the consensus is that
> if you need it every trip, then you have the wrong solution.
> The generator on an EV is not different than electric driven
> wheels powered by a generator in your concepts.
>
> If you want to innovate and save the environment, then the
> generator should be comparable to a modern car (Hybrid) or
> better. (Just giving you a challenge here ;-)
>
> Regards,
>
> Cor van de Water
> Systems Architect
> Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
> Skype: cor_van_de_water IM: [EMAIL PROTECTED]
> Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
> Fax: +1 408 731 3675 eFAX: +31-87-784-1130
> Proxim Wireless Networks eFAX: +1-610-423-5743
> Take your network further http://www.proxim.com
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of multi-Timm
> Sent: Sunday, April 09, 2006 8:59 AM
> To: ev@listproc.sjsu.edu
> Subject: the $5000 car - could use some expert help
>
>
> We are well into the development of our $5000 kit car that pretty much
> anyone can afford. It can be assembled as an EV or a hybrid, depending on
> whether the owner prefers a generator or more batteries in it's place.
> We're well covered on mechanical and design, but we do lack some
> EXPERIENCED experts in electrical. Currently there are only one or two
guys
> who are expert and doing all the pulling in electrical, so the group could
> use an extra person or two on the team. If anyone is interested, you are
> most welcome to join us.
> Hope to see you there:
> autos.groups.yahoo.com/group/SmallEfficientVehicles/members
> Timm
> http://autos.groups.yahoo.com/group/SmallEfficientVehicles/members
>
>
> T!MM! §
> http://www.nrdc.org/wildlife/marine/nlfa.asp
> http://groups.yahoo.com/group/Inventors-World/
> http://groups.yahoo.com/group/CADoutsourcing/
> http://autos.groups.yahoo.com/group/SmallEfficientVehicles/
> "We don't see things as they are, we see them as we are" (Anaïs Nin)
>
>
> ---------------------------------
> Enrich your life at Yahoo! Canada Finance
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.385 / Virus Database: 268.4.0/305 - Release Date: 08/04/2006
>
>
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--- Begin Message ---
On 9 Apr 2006 at 22:52, Michaela Merz wrote:
> If the foot is off the gas [sic] pedal and there's
> still voltage supplied to the motor: Throw the contactor.
Why not just open the contactor if the foot is off the accelerator? Other
than a bit of contactor noise, why bother with the voltage condition?
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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--- Begin Message ---
Some of you might find this paper of interest.
http://www.nasa.gov/centers/dryden/pdf/88628main_H-2283.pdf
Particularly note references 2 and 4:
2. White, R. A. and H. H. Korst, “The Determination of Vehicle Drag
Contributions from Coast-Down Tests,” SAE-720099, Jan. 1972.
4. Keller, Thomas L. and Robert F. Keuper, Comparison of the Energy
Method With the Accelerometer Method of Computing Drag Coefficients
>From Flight Data, NACA CB-5H31, 1945.
The NACA paper is particularly good. All the NACA papers are
available online from a NASA site. I don't recall the URL because I
have the entire set on my computer. A little googling will help.
John
PS: In view of the dates on these papers, reconsider the article
about that Phil Knox character and the comments there and on this list
to the effect that car and truck engineers are ignorant of this stuff.
I just shake my head in stunned amazement at the stuff that comes
across this list.
http://www.evworld.com/view.cfm?section=article&storyid=870
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
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--- Begin Message ---
i also suggested to have a look at the indian battery
operated car .. REVA ..
comments invited ..
..peekay
(4 seater .. 2 adults and 2 kids (nope not adults at the back !)
range 80 km .. speeds are slow
it is like an additional thingy .. aka golf car .. not a main stream
i guess .. but worth taking a look .. it is commercial .. and sells !)
----- Original Message -----
From: "Cor van de Water" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, April 10, 2006 2:33 AM
Subject: RE: the $5000 car - could use some expert help
> Timm,
>
> An EV would be interesting, but I read in your charter on this
> Yahoo group that you want to use a 2-stroke Diesel.
> To me that sounds like the wrong direction - you will increase
> pollution and be far worse than most new cars on the road today,
> so I urge you to re-think this path.
>
> Besides efficiency, there is a lot to gain in a clean car engine
> because a moped is efficient but nobody wants to run it indoors
> and even outdoors it can be bad.
> We have just been through this discussion in relation to use
> of a generator as range-extender for an EV.
> Incidental use may be beneficial, but the consensus is that
> if you need it every trip, then you have the wrong solution.
> The generator on an EV is not different than electric driven
> wheels powered by a generator in your concepts.
>
> If you want to innovate and save the environment, then the
> generator should be comparable to a modern car (Hybrid) or
> better. (Just giving you a challenge here ;-)
>
> Regards,
>
> Cor van de Water
> Systems Architect
> Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
> Skype: cor_van_de_water IM: [EMAIL PROTECTED]
> Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
> Fax: +1 408 731 3675 eFAX: +31-87-784-1130
> Proxim Wireless Networks eFAX: +1-610-423-5743
> Take your network further http://www.proxim.com
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> Behalf Of multi-Timm
> Sent: Sunday, April 09, 2006 8:59 AM
> To: ev@listproc.sjsu.edu
> Subject: the $5000 car - could use some expert help
>
>
> We are well into the development of our $5000 kit car that pretty much
> anyone can afford. It can be assembled as an EV or a hybrid, depending on
> whether the owner prefers a generator or more batteries in it's place.
> We're well covered on mechanical and design, but we do lack some
> EXPERIENCED experts in electrical. Currently there are only one or two
guys
> who are expert and doing all the pulling in electrical, so the group could
> use an extra person or two on the team. If anyone is interested, you are
> most welcome to join us.
> Hope to see you there:
> autos.groups.yahoo.com/group/SmallEfficientVehicles/members
> Timm
> http://autos.groups.yahoo.com/group/SmallEfficientVehicles/members
>
>
> T!MM! §
> http://www.nrdc.org/wildlife/marine/nlfa.asp
> http://groups.yahoo.com/group/Inventors-World/
> http://groups.yahoo.com/group/CADoutsourcing/
> http://autos.groups.yahoo.com/group/SmallEfficientVehicles/
> "We don't see things as they are, we see them as we are" (Anaïs Nin)
>
>
> ---------------------------------
> Enrich your life at Yahoo! Canada Finance
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.385 / Virus Database: 268.4.0/305 - Release Date: 08/04/2006
>
>
___________________________________________________________
NEW Yahoo! Cars - sell your car and browse thousands of new and used cars
online! http://uk.cars.yahoo.com/
--- End Message ---
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maybe switching to multiple brush sets wold be
easy .. sensors would set the correct relays to connect
postion .. cheaper too .. maybe
..peekay
----- Original Message -----
From: "David Sharpe" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, April 10, 2006 4:38 AM
Subject: Variable brush position for DC motor
>
> With regards to thread on regeneration lately another idea might be a
brush
> set whose position can be altered by some sort of servo driven by a
feedback
> control system using an auxiliary brush set that looks for a position of
> minimum voltage drop. The brushes would be parked in a neutral position
but
> the "polarity" of the auxiliary brush pair would tell the control system
> which way to send the brush set.
>
> David Sharpe
>
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.385 / Virus Database: 268.4.0/305 - Release Date: 08/04/2006
>
>
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To help you stay safe and secure online, we've developed the all new Yahoo!
Security Centre. http://uk.security.yahoo.com
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--- Begin Message ---
> Not fully loaded but at full throttle. There is a point somewhere
> near the torque peak that is the best BSFC (brake specific fuel
> consumption.) That is almost always less than the point of max HP.
> Full throttle is necessary with an SI engine for the pumping losses to
> be the lowest.
>
> Best BSFC is a balance between better VE and more efficient combustion
> as speed increases vs higher frictional losses as speed increases.
>
Could you use rpms at peak torque for a rough estimate? Some specs on small
diesel engines also have curves for fuel used per hp-hr, and these seem to
follow the torque curves pretty well. Not sure if the same goes for gas
engines.
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David Sharpe wrote [on powering the 3-phase slip rings]:
Motor design has a *long* and *very* rich history. Some of the greatest
engineering and scientific minds of the past 100 years have applied
themselves to the problem. If you think there are a lot of motor types
today, just look at some of the odd ones that have been invented in the
past! It is very hard to think of something that hasn't already been
tried!
If you put DC on the stator (field), and apply AC to the armature via
slip rings, you have an inside-out, wound rotor, synchronous motor.
Properly done, this type of motor has higher efficiency than either a DC
series or AC induction motor (though not as high as a permanent magnet
DC or AC). They were used in the past because they were easier to start
from a fixed-frequency AC supply. The main drawback is the need for slip
rings.
A wound-rotor AC motor was typically started by applying full voltage at
full frequency to the rotor windings via the slip rings. The field just
had a load resistor or inductor switched across it. The rotor isn't
moving, but the 3-phase AC in it creates a spinning magnetic field. This
field induces AC in the stator (field) winding by transformer action.
The load on the field deterines the field current, which in turn defines
the AC line current. In the extreme case, if you leave the field winding
open, the field current is zero, so the AC line current is (nearly)
zero. It just sits there and quietly hums, like a transformer with no
load on the secondary.
But when you draw current from the field with that load resistor or
inductor, you create field current. Now you have torque, and the rotor
begins to turn. The faster the rotor goes, the lower the frequency of
the induced voltage in the field winding. That's why they would use an
inductor instead of a resistor; The inductor doesn't get hot or waste
power, and it drew more current as the frequency went down, until it
became a dead short at synchronous speed. The motor would accellerate
smoothly up to full speed with a controlled AC line current all the way,
and then run with the shorted field as a conventional induction motor.
But then, to get higher efficiency and a better power factor, they
applied DC power to the field. Now it locked in at synchronsous speed,
and ran as a synchronous motor (what we now call "brushless 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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On Sun, 09 Apr 2006 21:48:29 -0700, [EMAIL PROTECTED] wrote:
>> Not fully loaded but at full throttle. There is a point somewhere
>> near the torque peak that is the best BSFC (brake specific fuel
>> consumption.) That is almost always less than the point of max HP.
>> Full throttle is necessary with an SI engine for the pumping losses to
>> be the lowest.
>>
>> Best BSFC is a balance between better VE and more efficient combustion
>> as speed increases vs higher frictional losses as speed increases.
>>
>
>Could you use rpms at peak torque for a rough estimate? Some specs on small
>diesel engines also have curves for fuel used per hp-hr, and these seem to
>follow the torque curves pretty well. Not sure if the same goes for gas
>engines.
>
Yep, peak torque is usually good enough for field work. The only
problem is that industrial engines, especially diesels, tend to have
rather flat torque curves so finding the peak is difficult. Those
hp-hr curves are usually more useful when they're available.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
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--- Begin Message ---
David Sharpe wrote:
>
> Has anyone been able to charge flat AGMs. I have tried charging using about
> 50V DC in series with a 100W light bulb. 2V appears on the terminals but the
> trial cell will not charge. Any suggestions?
> David Sharpe
If they were allowed to run very dead, their internal resistance can be
so high that no current will flow. No current means they don't charge;
thus they STAY dead.
If there is nothing else wrong with the AGM (it's just deeply
discharged, not defective), then leave a moderately high voltage on it
(about double its rated voltage, i.e. 24v for a 12v battery), with a
resistor or light bulb or something to limit the current to about 1-2%
of its rated amphour capacity.
Initially, the battery may go right up to 24v and draw almost zero
current. Keep checking the current every so often. A light bulb is handy
because you can *see* when it starts to draw current. Over a period of
hours or DAYS, you should see the current s-l-o-w-l-y start to rise. It
rises faster and faster as it charges. If all goes well, you'll reach a
point when the current suddenly increases dramatically, as high as your
light bulb or resistor allows, and the voltage falls back to what you
would expect for a dead battery (something under 12v for a 12v battery).
Now you can remove the high voltage source and light bulb, and charge it
with a normal charger.
--
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 ---
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On Mon, 10 Apr 2006 10:02:32 +0530, "peekay"
<[EMAIL PROTECTED]> wrote:
>this is a very novel idea .. the only issue is getting a jeweller's scale
This is a very old idea, going back at least a couple centuries.
Especially before calculators, scientists had to come up with all
sorts of nifty tricks in order to get work done instead of grinding
out endless calculations.
>
>may i humble suggest :
>
>cut a plywood sheet to match the paper size, paste the printout..
>cut the car image out .. weighing is easier .. kitchen scale can be used.
Yes, that will work well but only if the plywood is very uniform - no
internal voids or glue pockets. Particle board or OSB would probably
be better than plywood. Adding weight to the paper is why I suggested
printing on the heaviest stuff that would feed through the printer.
I mentioned the jewelers because most jewelers have some sort of
sensitive scales. Just haul your two pieces of paper to the store and
ask to weigh them. The novelty of the request almost always meets
with success. That was my standard method before I acquired a
suitable balance of my own.
As an aside, I've had a life-long hobby/avocation (since about the age
of 6, anyway) of collecting old technical, scientific and mathematical
books. My library now numbers in the thousands of volumes and is one
of the most valuable resources I have, right behind the net.
It is quite unfortunate in this day of computers and calculators and
new math that the old methods of computation, measurement and other
shortcuts aren't taught anymore. These methods are frequently as fast
or faster than computational methods with adequate accuracy for the
job at hand. These methods also can usually be used without a
Pentagon budget to buy test equipment and computers.
I'm reminded of Enrico Fermi's estimation of the yield of the first
atomic bomb to better than 10% by merely dropping scraps of paper into
the blast wave as it went by, measuring the distance they were
deflected and using some approximations that he could do in his head
with the aid of his ever-present slide-rule, came up with about the
same number as the instrument guys did, only they took weeks to crunch
the numbers.
I only wish I had the time and money to scan these old books and put
them on the net. Meanwhile, the used book stores are the engineer's
best friends.
Probably the most useful lesson I learned in school was taught to me
by my 9th grade chemistry teacher. He taught that most problems can
be reduced to simple ratios. Many of the more complex parts of
problems reduce to either constants, 0 or 1 and can be ignored. He
was absolutely correct. I extend the notion by adding an occasional
exponent, root or log to the simple ratio.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
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--- Begin Message ---
I'm in the process of installing one of John Lussmyer's battery
monitors and some general upgrading of my EV Buggy. I thought that some
of the list members might like a look at what is "under the hood" of
the Buggy. The monitor is not installed quite yet, but the wiring now
goes from the back of the buggy to the front. The bonnet is off to
allow for me to finish the installation and for some minor 12 volt
wiring upgrades.
The link to the upgrade picts is:
<http://paul-g.home.comcast.net/buggy.htm>
Paul "neon" G.
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On Sun, Apr 09, 2006 at 10:52:28PM -0500, Michaela Merz wrote:
>
> Since I read about how bad DC controllers might fail (well, I kind of knew
> that before but .. ) I was driving down the road with my foot on the
> clutch. And I was thinking: It can't be too complicated to have some sort
> of fail safe that would 'kick in' if a controller breaks down.
<..snip..>
I had a similar idea when this was last discussed. Otmar came up with
an even better idea, which he had already implemented in his controllers :)
That's how you know when you've been out done :)
----- Forwarded message from Otmar <[EMAIL PROTECTED]> -----
From: Otmar <[EMAIL PROTECTED]>
Subject: Re: Trip in Emergency Only
At 3:16 PM -0800 2/24/06, Nick Austin wrote:
>Are there any symptoms of a controller "fail full on" condition that can be
>easily detected? If there are, then the best system would check for this,
>and
>open the main contactor if the condition is detected.
>
>I was thinking something like throttle < %50, Motor current > x, for longer
>then 500ms == probable controller failure, open main contactor and
>pop a toggle
>switch (for manual reset).
>
>I guess the tricky part is figuring out what x should be, getting the data
>and actually building this thing.
Hi Nick,
Those were my thoughts exactly. Except that it would also be nice to
detect a failure before the user released full throttle.
The Zilla and Hairball combination do something very similar to this.
If motor current is more than about 30 amps, and the motor voltage
has not been at zero in the last 100ms, then the Hairball drops the
main contactor. The Zilla quickly pulses off once every millisecond
when at "full duty cycle" in order to allow this check to work.
Fortunately, I've never heard of a power system failure causing this
trip. There were some adjustments I had tuned a bit too close that
would cause false trips. Could it have happened farther away than
Australia? I think not. Fortunately Mark Fowler was patient and my
tech just happened to be down under so he could make a house call. :)
In addition if the Zilla fails to communicate for a short time then
the Hairball also drops the main, this since it is hard to know if
the Zilla brains would survive a major power section failure.
So yes I think it's a good idea and that's why I put it in the Zilla
series of controllers.
--
-Otmar-
http://www.CafeElectric.com/
The Zilla factory has moved to Corvallis Oregon.
Now accepting resumes. Please see:
http://www.cafeelectric.com/jobs.html
----- End Forwarded message -----
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