EV Digest 2557
Topics covered in this issue include:
1) Re: Sparrow Battery Trailer (was E-teks for Sparrows)
by Lee Hart <[EMAIL PROTECTED]>
2) Re: Competition started (was Truck (im)possibility)
by Otmar <[EMAIL PROTECTED]>
3) Re: 20 minute charge to 80%
by "Chuck Hursch" <[EMAIL PROTECTED]>
4) Internet Virus affecting traffic on Saturday
by Chip Gribben <[EMAIL PROTECTED]>
5) Re: E-tek Sparrows (was Re: AC Drives (Sparrow?))
by Peter VanDerWal <[EMAIL PROTECTED]>
6) RE: Dump charger with manners (was RE: 20 minute charge to 80%)
by "George Tylinski" <[EMAIL PROTECTED]>
7) Re: Dump charger with manners (was RE: 20 minute charge to 80%)
by "Joe Smalley" <[EMAIL PROTECTED]>
8) Vent plugs for batteries
by "Johanna and Stan" <[EMAIL PROTECTED]>
9) long NiCad strings?
by Jim Coate <[EMAIL PROTECTED]>
10) Re: Truck (im)possibility, Regen on ADCs.
by [EMAIL PROTECTED]
11) Re: Vent plugs for batteries
by "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
12) Re: E-tek Sparrows (was Re: AC Drives (Sparrow?))
by "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
13) Re: E-tek Sparrows (was Re: AC Drives (Sparrow?))
by "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
14) Re: Accessory belts, was:Truck (im)possibility, Regen on ADCs.
by [EMAIL PROTECTED]
15) Amherst, MA - Feb 9 - "Cleaner, Greener Transportation"
by Jim Coate <[EMAIL PROTECTED]>
16) Re: Sparrow Battery Trailer (was E-teks for Sparrows)
by Edward Ang <[EMAIL PROTECTED]>
17) Re: Internet Virus affecting traffic on Saturday
by Eric Penne <[EMAIL PROTECTED]>
18) Re: Internet Virus affecting traffic on Saturday
by Peter VanDerWal <[EMAIL PROTECTED]>
19) Re: Dump charger with manners (was RE: 20 minute charge to 80%)
by Lee Hart <[EMAIL PROTECTED]>
20) Re: Dump charger with manners (was RE: 20 minute charge to 80%)
by Lee Hart <[EMAIL PROTECTED]>
--- Begin Message ---
Thomas Shay wrote:
> I don't think that towing a battery trailer behind a Sparrow has
> been discussed here before. My first thought was that the idea
> was absurd, but maybe it isn't. A two wheel trailer and the right
> coupling arrangement might add stability to the Sparrow somewhat
> like training wheels do on a child's bicycle.
Now, that prompted an idea. Once upon a time there was a company called
LeJay that made "electric wheel" sidecars for bikes. Basically, it was a
little box with the batteries, motor, and a wheel that bolted on beside
the back wheel. It had its own tire to carry all its weight, and was on
suspension so it could pivot as the bike leaned in turns. The thrust it
produced was of course off-center; but there wasn't enough to be that
serious a problem. Or, you could use two of them, one on each side.
I wonder what would happen if you made a pair of "side cars" for a
Sparrow, each with its own wheel that rode alongside the normal centered
back wheel? These wheels could follow in the tracks of the front wheels,
but have their axles lined up with the back wheel. In effect, you'd have
something like a 5-wheeled vehicle with 2 front and 3 back wheels.
It would be pushing into entirely unknown territory, but it also might
work!
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Peter VanDerWal wrote:
>
> > Last thing - any guess for a rolling resistance (with and without
> > trailer) of this 8 ton beast.
>
> Assuming you are looking for a coefficient, How does 0.015 sound?
Regular car (not LRR tires) usually has it 0.01. A trailer will add
0.005 if it has two wheels (one axle) and single wheel on each side
(not double wheels like those on the rear axle of a school bus, not
sure what is it called). Id the wheels are doubles, i.e. four tires
touch the ground, or there are two axles on the trailer, I'm afraid
it will be 0.02 - twice as bad as without trailer.
Um, am I missing something or are we way off here?
Coefficient as I understand it is the ratio of drag to weight on the wheel.
Therefore, assuming you figure the weight of the combined vehicle,
and that that weight is never put to the ground more than once, it
really doesn't matter how many tires there are. Each tire has some
share of the load, and the ones with higher load will produce more
drag. Except for non linear effects of tires, you can pretend the
whole trailer and truck is one item on one tire and come up with the
same result.
My results are very accurate in terms of reflecting Siemens system
and battery model. It will only give significant an error if you
feed wrong data in. Like every 0.001 off of the rolling coeff adds 10%
to the error.
But the error is only for the rolling portion of the drag, yes? If
that was true at 60 mph then your model would not be very accurate
since most of the drag is aerodynamic at that speed.
I'm curious to see the results.
BTW, for figuring acceleration from a stop there are easy ways to get
a feel for it. It involves figuring out the acceleration in Gs while
ignoring aerodynamic losses.
I find that a car with 0.5 G acceleration feels reasonable. My 914 is
very fast and is close to twice that. A car with only 0.25 Gs of
acceleration feels unbearably slow to me.
There is a great meter called a G-Tech that can be used for measuring
Gs, It costs only about $150.
In order to figure the Gs when starting out, pick the gear ratio you
will be running, and do some multiplication.
For example let's see if I can do this for my 914:
Motor torque = 600 ft/lb.
Ratio from motor to wheel 3.75:1 (third gear is what I run in)
Wheel diameter 21.25"
Vehicle weight with driver 3175 lbs.
So, the motor torque is multiplied by the ratio to get wheel torque:
600 * 3.75 = 2250 ft/lb
Since we are dealing with "foot" lbs, this is divided by the lever
arm on the wheel in feet, which is 1/2 the diameter. which is 0.885
feet for this car.
2250/0.885 = 2542 lbs of force.
We now divide the force by the total weight to get the acceleration in Gs.
2542 / 3175 = 0.8 Gs.
I find this is about right since that's close to what the G-Tech
shows on the street for 1400 Amp acceleration. I could turn it up
higher, but then the tires usually don't hold. :-)
This will not tell you speed up a grade, because it does not consider
air drag, but I find it especially useful for getting an idea for how
peppy a car will feel (especially when doing single ratio) off the
line.
HTH,
-Otmar-
http://www.CafeElectric.com/ New Z2K controller, now available.
http://www.evcl.com/914 My electric 914
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
> Peter VanDerWal wrote:
> >> The major problem is simply getting the power to the
charger...
> >> you have to put over 56kw into the pack for 20 minutes...
more
> >> than twice what the average household power panel is rated
for.
>
> Chuck Hursch wrote:
> > Seems like high-power Level III(+) charging would be in the
> > domain of fast-fill service stations with industrial-level
power
> > feeds.
>
> There is an alternative. I like the idea of having a home
dump-charger
> setup. You have one set of batteries in your EV, and a second
set in
> your garage. This second set is on a float charger, which can
take all
> day to charge them. By including an inverter, they can also
provide
> emergency power for your house in case of a power outage.
>
> To fast-charge your EV, you dump-charge it from this second
pack. You
> get a very fast charge, without requiring a high-power AC power
feed.
This is what Preston McCoy (he helped me do the conversion) and I
were looking at when it was questionable whether I would have
charging at my apt. Preston's is about 6-8 miles and two hill
climbs (depending on how you go) from my apt. Fortunately, I was
able to set up charging at my apt. I rather doubt the EV scene
would've worked otherwise. The pack would've been going several
days between charges, and I doubt with all the hassle I and the
pack could've lasted. So I've had the charging going at the apt
for 8-1/4 years now with nary a problem. I hope, and expect,
that it will remain that way for the duration of my residence
here.
>
> > Hey, does anyone have any thoughts as to what is going to
happen
> > with the current charging infrastructure now that all the
> > production vehicles are gone.
>
> You *know* what will happen. They will all fall into disrepair,
and get
> ripped out. Nobody is going to pay to maintain them. By the
time the
> pendulum swings and we reach the next EV boom in 5-10 years,
they will
> all be consider "obsolete" and nobody will use them anyway.
Yep, that gives me second thoughts on setting up an Avcon port +
charger. Knowing my turtle pace, I'll get that all set up about
the time the infrastructure disappears. But I think I will
proceed anyways. The exercise is worthwhile, and once I have the
Avcon port and charging set up, I'm most of the way there for
whatever else comes along.
Chuck Hursch
Larkspur, CA
NBEAA treasurer and webmaster
www.geocities.com/nbeaa
http://www.austinev.org/evalbum/339.html
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--- Begin Message ---
There appears to be a worm or virus affecting internet traffic today. It
must be bogging down the routers.
I was attempting to update the EVA/DC website but cannot access the site or
any of my other sites for that matter. Hopefully things will clear up later
today as hosting providers respond to the situation.
Chip Gribben
Webmaster
Electric Vehicle Association of Washington DC
http://www.evadc.org/
Power of DC
http://www.powerofdc.org
--- End Message ---
--- Begin Message ---
> > If the brushes are set for neutral timing then
> > efficiency is NOT over 90%,
> I never said over 90%. Really about 89% in the
> graphs. Picky, picky, picky!!! ;-))
> Like Otmar said, about 20% more eff, range than
> the stock Sparrow set-up including controller, regen
> YMMV.
Otmar didn't say that E-teks would be 20% more efficient. He said that
most EVs can be made up to 20% more efficient by doing many things.
If the E-tek setup was 20% more efficient than the ADC motor setup it
would be over 100%.
> > >The low 48vdc helps a lot I believe. This
> > >allows a low cost batt pack too and good power, 9hp
> > >cont and 20hp peak per motor.
> >
> > Where are you getting the 9hp figure from? The
> > online material states a
> > maximum of 7hp at 120 amps. At that point on the
> My e-tek is stamped on it's alum housing 150
> amps cont. That rates out at 7.5kw which at > >
> > >What does IIRC mean?
> > If I Recall Correctly
> Thanks and to others who clued me in.
> Other posts,820
> watts/hp works out to 9.1hp at 50 vdc each.
Except that the motor is not 91% efficient at that power level (in fact
it's NEVER 91% efficient). 150 Amps according to the torque charts
looks to be around 86%. Also how are you planning on getting 50V to the
motor? Use a 52V pack?
A 48V single string of YT's will sag to about 46V when pushing 150
amps. 46V * 150A = 6900 watts x 86% = 5934 / 746 = just under 8 hp
I'll grant you this is more than the 7 hp listed on EV parts site.
.
> Peak is 330 amps which comes to 16.5kw = 18.33hp
> at 900watt/hp times 2 motors. A lot faster than many
> EV's in a Sparrow.
And how many seconds can it handle peak current?
> > torque chart efficiency> >
> > >What does IIRC mean?
> > If I Recall Correctly
> Thanks and to others who clued me in.
> Other posts,
> > looks like about 87-88%
> Looks like 89% to me.
> >
> > If you add some external cooling you could possibly
> > get 9hp continuous (that
> > requires 180 amps!!!) but efficiency drops some
> > more, looks like 86% or so.
> See above. Where do you get 180 amps for 9hp?
> It's not a series motor.
Right off the torque chart, see above.
> > Perhaps, but even with two E-teks this is
> > significantly less power than the
> > standard setup. The stock Sparrow setup can produce
> > 30hp continuous and
> While it can produce that kind of power it can't
> handle that much and has the controllers turned down
> to keep them safe so the extra power is a waste.
My figures were for the tuned down controller. See John's post where he
uses 26 hp continuous for climbing a long hill.
> With 2 motors at 18 hp cont, 36.6hp peak, The
> e-tecs will do very well on the Sparrow topping 80 mph
> with some hp left over for hills. I'd gear for 70 mph
> for more pick-up, eff.
No they won't. Peak HP on E-teks lasts for seconds (30?) they don't
have enough thermal mass to handle power levels much above continuous
rating for very long.
> We were looking for more range, not faster drag
> racing.
He is also looking to be able to complete his trip, I assume he wants to
drive in the same manner he does now.
> > over 120hp maximum. Two E-teks can produce 14 hp
> > continuous (less than 1/2)
> > and 30 hp Maximum (about 1/4 the power).
> > Might work but it would be a serious performance hit
> > for the Sparrow,
> > whether or not that is acceptable is up to the
> > owner.
> See above. Also PMs make better power at higher
> rpms when you need it where series drops off fast.
>
PM have an almost linear power curve where series is 'slightly' curved
at these power levels. For equivalent rated motors this might make a
small difference, two E-teks are far below the series motor in this case
and never catch up.
> For rpm the e-tek should be limited to 4000rpm
> though racers do 6,000rpm, 72vdc with it but I want
> reliability.
And the ADV is right in it's sweet spot (efficiency and power wise) at
4,000 RPM. They are rated up to 6,000 rpm IIRC and racers have taken
them beyond that.
--- End Message ---
--- Begin Message ---
I like the simplicity of contactors v. PWM controller... But how to
estimate what the current v. time curve would look like, in order to
thermally size the cabling? And would it blow the fuses that are in the
"normal" logical places?
Using the motor as an inductor for the PWM - is that to smooth the
square wave to an average V?
- GT
> -----Original Message-----
> From: Lee Hart [mailto:[EMAIL PROTECTED]]
> Sent: Friday, January 24, 2003 11:31 PM
> To: [EMAIL PROTECTED]
> Subject: Re: Dump charger with manners (was RE: 20 minute
> charge to 80%)
>
>
> George Tylinski wrote:
> > what would it take to make a "dump charger with manners" using a
> > modest motor controller and a 2nd battery pack too weak for the
> > vehicle but good enough to bring your SOC from 20% to 80%?
>
> 1. The batteries for your dump pack (about 10% higher voltage than
> the pack in your car).
> 2. An AC charger for these batteries (could be small; can
> take all day). 3. Meter so you can tell their state of charge
> (E-meter is great, but
> just a voltmeter is adequate).
> 4. Charge controller. Could be as simple as a big contactor and a
> voltage sensor that cuts it off when your EV batteries reach a
> safe level around 80-90% charged. Or, you could use a PWM
> controller
> and inductor (even the one already in the car and the
> motor's field)
> and implement a proper multi-step charging algorithm.
> 5. Safety circuits, just in case something goes wrong.
> --
> Lee A. Hart Ring the bells that still can ring
> 814 8th Ave. N. Forget your perfect offering
> Sartell, MN 56377 USA There is a crack in everything
> leeahart_at_earthlink.net That's how the light gets in -
> Leonard Cohen
>
--- End Message ---
--- Begin Message ---
There are a few holes in the logic...
1. If a pack is too small to run the car, then it holds too few kilowatt
hours to move the car a reasonable distance. If you use this battery pack to
store the charge, then the energy it holds it will only move the car 80% of
the distance the pack would move it.
For instance, if the dump pack only holds 5 kilowatt hours, then it can only
dump 4 kilowatt hours into the car if the dump charger is 80% efficient.
2. The voltage sag of the donor pack during a dump charge will probably come
down to about 10 volts per 12 volt block and the pack being charged would
come up to nearly 15 volts per 12 volt block.
For example, a 120 volt pack will need to come up to 150 volts during
charge. You will need at least 160 volts into the controller to get this
output if you budget for voltage drops in the current loop. Therefore you
need 16 (12 volt) batteries to produce a good dump current. The pack should
be 192 volts to operate properly.
3. The higher voltage dump pack needs to have an ampere hour capacity AT THE
DUMP CHARGE CURRENT as the battery being charged needs to absorb. This means
the Peukert effect will take a big chunk out of the dump pack capacity.
For example, a Trojan T105 (http://www.altenergystore.com/cart/379.html) is
rated at 225 AHr at the 20 hour rate but only 143 at 75 amps. This battery
has only 63% of its full capacity when operated at 75 amps instead of 10
amps.
Summary:
-The dump charge pack needs to be more than 50% higher in voltage than the
pack being charged if you are using the common buck converter for a
controller.
-The dump pack ampere hour capacity needs to be larger than the pack being
charged AT THE DUMP CHARGE CURRENT.
Another option:
The PFC-50 architecture can be used as a dump charger. The present design
works if the input circuit breaker is changed to a DC rated device. The
present configuration is set up for as much as 400 volts peak input and
output. If the voltage limits were reduced, the current limits can be
increased. As it sits, it is capable of running off as little as 120 VDC to
as much as 380 VDC. If the voltage limits (both input and output) were
reduced to less than 200 volts peak, then the existing design should be
capable of over 150 amps as a dump charger. The safety circuits and control
issues have already been worked out.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "George Tylinski" <[EMAIL PROTECTED]>
To: "'EV'" <[EMAIL PROTECTED]>
Sent: Friday, January 24, 2003 2:37 PM
Subject: Dump charger with manners (was RE: 20 minute charge to 80%)
> Yes, but... what would it take to make a "dump charger with manners"
> using a modest motor controller and a 2nd battery pack too weak for the
> vehicle but good enough to bring your SOC from 20% to 80%?
>
> 1. a pair of contactors and fuses
> 2. cooling system for the controller
> 3. Automatic shut-off at prescribed voltage
> 4. ?
>
> Stretch it a little further and you could use the on-board controller if
> you don't mind the extra baggage. On second thought maybe that should be
> essential for economic reasons...
>
> - GT
>
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* LP8.2: HTML/Attachments detected, removed from message *
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Has anyone stacked up NiCads in 300-400 volt strings?
Does it work well?
With long NiCad strings, is there need for active balancing (like lead
acids), or does the regular 15% overcharge keep them all happy?
Dreaming again,
_________
Jim Coate
1992 Chevy S10
1970's Elec-Trak
http://www.eeevee.com
--- End Message ---
--- Begin Message ---
> Mike Slominski had a generator regen setup in his Rabbit with a
> DC motor (GE?).
It was a substitute DC/DC, keeping his 12 volt topped up.
Paul Compton
BVS technical officer www.bvs.org.uk
www.sciroccoev.co.uk
--- End Message ---
--- Begin Message ---
On 25 Jan 2003 at 11:31, Johanna and Stan wrote:
> We heard that vent plugs cut down on the need for adding water to batteries -
> has anyone had experience with these and do they work?
Maybe I'm misunderstanding something here. Are you talking about literally
plugging up the vent holes in the cell caps? That would be dangerous.
During the last 20% of charge, batteries produce hydrogen and oxygen gas.
If the vents are plugged, the gases can't escape. The pressure will build
up and try to vent wherever it can. If the seal is good enough, the battery
could rupture from the pressure.
VRR ("sealed") batteries use a catalyst to help recombine H2 and O2 into
water. They also have pressure valves to release the gases in case the
battery produces them faster than the recombination reaction can handle
them.
Are you maybe thinking of Hydrocaps? These are gadgets which contain a
similar catalyst. They're sometimes used in home alternative energy
systems, and I understand they're successful (to some degree) in reducing
water usage. But they add quite a bit of height to the battery, something
like 2" or more, and this might pose a problem for the tight quarters that
are typical in EVs. I don't think they're anyting like $5 each, either,
though I suppose there might be some shoddy far-east sweatshop imitations
out there selling for less.
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David Roden - Akron, Ohio, USA
1991 Solectria Force 144vac
1991 Ford Escort Green/EV 128vdc
1970 GE Elec-trak E15 36vdc
1974 Avco New Idea rider 36vdc
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--- Begin Message ---
On 25 Jan 2003 at 8:46, Peter VanDerWal wrote:
> If the E-tek setup was 20% more efficient than the ADC motor setup it
> would be over 100%
This doesn't make sense.
What do we mean when we say "motor A is twice as efficient as motor B"? I
^think^ we mean that A wastes half as much. So if B is 80% efficient,
wasting 20% of its input, then A must be wasting only 10% of its input, so
it's 90% efficient.
Suppose we have a motor with 80% efficiency. Poof, a miracle happens, and
now it's 20% more efficient. Thus, it now wastes 20% less than it used to.
Of every 100 Watts going in, instead of 20 Watts being lost as heat, only 16
Watts is lost. So our miraculously 20% more efficent motor now has 84%
efficiency.
Make sense? Or am I way off base here?
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David Roden - Akron, Ohio, USA
1991 Solectria Force 144vac
1991 Ford Escort Green/EV 128vdc
1970 GE Elec-trak E15 36vdc
1974 Avco New Idea rider 36vdc
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On 24 Jan 2003 at 21:31, jerry dycus wrote:
> I wouldn't try a trailer on a Sparrow for
> handling reasons.
Jerry is probably right. He knows three-wheelers. Still ... heck, bicycles
pull trailers. Surely there's a way to make it safe and stable, or at least
as stable as a Sparrow ever gets. A trailer's such an easy way to add
capacity and range that I hate to let go of the idea without exploring it
more deeply.
No trailer? Absolutely not? Well, how much more ground clearance can you
manage? Can you find another 3.5"? That would be enough room for a layer
of Hawker G16EPs (3" wide), lying on their sides. If you could fit in 13 of
them (dimensions 3" x 7.15" x 6.6", weight 14.7lb each) you'd have almost 2
more kWh. Squeeze 26 in ($$$) and you double that.
Or, hmm, what could you do with some F-size sealed nicads slung under the
body pan? Isn't that what the Insight uses? How many D-size NiMH like the
Prius could you fit in, all in series and bucked down to 156 volts? Now I'm
really daydreaming!
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David Roden - Akron, Ohio, USA
1991 Solectria Force 144vac
1991 Ford Escort Green/EV 128vdc
1970 GE Elec-trak E15 36vdc
1974 Avco New Idea rider 36vdc
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>
>Thanks Lee and Otmar - I'm definitely going to file this in the
>email folder for my notes.
echo that!
>Assuming one managed to attach a pulley to the ADC shaft sitting
>in the motor, there are two or three other things that one would
>need to consider in a high-level view.
Assuming is right - my current motor (ex-industrial) has a hardened shaft -
drill? Tap? not a chance. Before you start to plan too far, give the end of
your motor shaft a rub with a file, if it skates off, it's hardened, if it
cuts, plan away!
>One is some kind of clutch to disengage the alternator and
>(belt?) drive from the ADC motor. I understand alternators can
>exert a significant drag, especially at high-rpms. (Good for
>regen, bad for anything else, like coasting.) Any ideas on
>clutches?
Unless you are into some serious power, an electric clutch from a normal
ICE air conditioner should handle the power, and for the short time that it
is on, the 25 to 100 watts the clutch takes (seem to vary a lot between
types) wouldn't be many watt-hours (which are being regened anyway).
>Need a high-voltage alternator to charge a pack. It'll be
>passing a lot more power than for 12V accessory battery charging,
>so there's a consideration in terms of cooling.
See Lee Hart's post, and remember all of the converted alternators doing
duty as welders out there.
<snip>
>Cogged-tooth belt drive? What would be best? I don't think
>there is enough room on my Rabbit to attach a clutch and
>alternator to the end of the ADC. I think it would have to be
>attached to a framemember up front of the motor, about one foot
>away.
Not a cogged belt - they are for "must'nt slip"application, where
efficiency is secondary. Go see your local bearings-and-belts supplier,
tell them the power you are pushing (/pulling) and you will find that
possibly a low-drag 'A'-section belt will do your job - particularly if you
will be running the belt 100% of run time, with clutch away from the motor.
I'd be attempting to sneak the clutch onto the end of the motor, if you can
find that 1-1/2 inch or so needed.
Another option if you're out of length-wise space would be to put a 'lay'
shaft alongside the motor, with the clutch on the end of the lay shaft,
stepped back from the end of the motor so you only need enough space for
the pulley and belt. Off that lay shaft you can run anything else - Vac.
pump or whatever, spaced as needed in the motor bay. My father had to use a
lay-shaft when he replaced the diesel in his boat - not enough space on the
belt-drive end.
>Are the bearings in an ADC going to be able to withstand the
>sideways load exerted by a belt?
Going by the long run-life of ADC motors, and the number that are in use
with clutches pushing on them (assuming many without an additional
end-thrust bearing), you would have no problem.
>Chuck Hursch
>Larkspur, CA
>NBEAA treasurer and webmaster
>www.geocities.com/nbeaa
>http://www.austinev.org/evalbum/339.html
Just my $0.02AU worth - about $0.0084US worth. (Advice is worth what you pay).
James Massey
Industrial Technik
Launceston, Tasmania, Australia.
Daihatsu 1300kgGVM cab/chassis truck conversion in progress,
Cat M50 electric fork in use,
Home made E-bike conversion languishing in corner.....
--- End Message ---
--- Begin Message ---
CLEANER, GREENER TRANSPORTATION
Paul Lipke, Sustainable Step New England
Mark Skinder, Pioneer Valley Biodiesel Cooperative
Chris Mason, NESEA
Karen Jones, Pioneer Valley Electric Automobile Assoc.
Sunday, Feb. 9, 1:00 - 4:00 p.m.
The Hitchcock Center for the Environment
525 S Pleasant Street, Amherst, MA
Members: $8; Non-members: $12
Travel cleaner, greener and with more fun per mile. Give less money to
Osama bin Laden and "Big Oil". Learn about, look under the hood, and
test-drive cars that run on grease or bio-diesl (made commercially from
vegatable oils or salvaged from restaurant fryer waste), electricity, or
are gas-electric hybrids while dramatically reducing polluting
emissions.
Paul Lipke, Sustainable Step New England, and Mark Skinder, Pioneer
Valley Biodiesel Cooperative, will share the issues that inspired them,
and the steps they took to convert their own cars. Try out a recumbent
bicycle. Then figure out which clean and green options make the most
sense for you given you particular travel patterns in a Sustainable
Transportation Clinic. Biodiesel and grease-powered cars are two
example, but we'll tailor information to meet attendees' interests in
mass transit, the most fuel efficient cars in each class, Zipcars, Clean
& Green Maps, bicycling routes, carpooling resources and other options
to help you get around using less gasoline.
For Further Information:
Contact the Hitchcock Center at 413-256-6006.
http://www.hitchcockcenter.org/comm_programs.htm#transport
_________
Jim Coate
1992 Chevy S-10
1970s Elec-Trak E20
http://www.eeevee.com
--- End Message ---
--- Begin Message ---
--- Lee Hart <[EMAIL PROTECTED]> wrote:
> Now, that prompted an idea. Once upon a time there
> was a company called
> LeJay that made "electric wheel" sidecars for bikes.
> Basically, it was a
> little box with the batteries, motor, and a wheel
> that bolted on beside
> the back wheel. It had its own tire to carry all its
> weight, and was on
> suspension so it could pivot as the bike leaned in
> turns. The thrust it
> produced was of course off-center; but there wasn't
> enough to be that
> serious a problem. Or, you could use two of them,
> one on each side.
>
> I wonder what would happen if you made a pair of
> "side cars" for a
> Sparrow, each with its own wheel that rode alongside
> the normal centered
> back wheel? These wheels could follow in the tracks
> of the front wheels,
> but have their axles lined up with the back wheel.
> In effect, you'd have
> something like a 5-wheeled vehicle with 2 front and
> 3 back wheels.
>
> It would be pushing into entirely unknown territory,
> but it also might
> work!
And, I thought my Sparrow is weird looking enough.
This would make it a ... 3x5?
Ed Ang
__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
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--- End Message ---
--- Begin Message ---
>From Slashdot.org:
defile writes "Since about midnight EST almost every host on the
internet has been receiving a 376 byte UDP payload on port ms-sql-m
(1434) from a random infected server. Reports of some hosts receiving
10 per minute or more. internetpulse.net is reporting UUNet and
Internap are being hit very hard. This is the cause of major
connectivity problems being experienced worldwide. It is believed this
worm leverages a vulnerability published in June 2002. Several core
routers have taken to blocking port 1434 outright. If you run Microsoft
SQL Server, make sure the public internet can't access it. If you
manage a gateway, consider dropping UDP packets sent to port 1434."
bani adds "This has effectively disabled 5 of the 13 root nameservers."
Eric
--- Chip Gribben <[EMAIL PROTECTED]> wrote:
> There appears to be a worm or virus affecting internet traffic today.
> It
> must be bogging down the routers.
>
> I was attempting to update the EVA/DC website but cannot access the
> site or
> any of my other sites for that matter. Hopefully things will clear
> up later
> today as hosting providers respond to the situation.
>
> Chip Gribben
> Webmaster
> Electric Vehicle Association of Washington DC
> http://www.evadc.org/
> Power of DC
> http://www.powerofdc.org
>
>
>
>
__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
http://mailplus.yahoo.com
--- End Message ---
--- Begin Message ---
Hmm, I've been seeing those hits on my firewall for weeks now. Odd
thing is I've only seen three of them in the last three days, all of
them yesterday.
On Sat, 2003-01-25 at 07:24, Eric Penne wrote:
> >From Slashdot.org:
>
>
> defile writes "Since about midnight EST almost every host on the
> internet has been receiving a 376 byte UDP payload on port ms-sql-m
> (1434) from a random infected server. Reports of some hosts receiving
> 10 per minute or more. internetpulse.net is reporting UUNet and
> Internap are being hit very hard. This is the cause of major
> connectivity problems being experienced worldwide. It is believed this
> worm leverages a vulnerability published in June 2002. Several core
> routers have taken to blocking port 1434 outright. If you run Microsoft
> SQL Server, make sure the public internet can't access it. If you
> manage a gateway, consider dropping UDP packets sent to port 1434."
> bani adds "This has effectively disabled 5 of the 13 root nameservers."
>
>
>
> Eric
>
>
>
> --- Chip Gribben <[EMAIL PROTECTED]> wrote:
> > There appears to be a worm or virus affecting internet traffic today.
> > It
> > must be bogging down the routers.
> >
> > I was attempting to update the EVA/DC website but cannot access the
> > site or
> > any of my other sites for that matter. Hopefully things will clear
> > up later
> > today as hosting providers respond to the situation.
> >
> > Chip Gribben
> > Webmaster
> > Electric Vehicle Association of Washington DC
> > http://www.evadc.org/
> > Power of DC
> > http://www.powerofdc.org
> >
> >
> >
> >
>
>
> __________________________________________________
> Do you Yahoo!?
> Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
> http://mailplus.yahoo.com
>
--
EVDL
--- End Message ---
--- Begin Message ---
George Tylinski wrote:
> I like the simplicity of contactors v. PWM controller... But how to
> estimate what the current v. time curve would look like, in order to
> thermally size the cabling? And would it blow the fuses that are in
> the "normal" logical places?
As a rule of thumb, if you force a flooded battery to its gassing
voltage (about 2.37v/cell, or 14.2v on a 12v battery), the charging
current will be approximately equal to the number of amphours needed to
reach full charge.
For example, suppose you have a 12 volt, 60 amphour flooded lead-acid
battery. It is at 50% SOC, which means it needs 30 amphours to recharge
it. If you connect it to a high-current 14.2v supply, it will initially
draw a huge surge, then settle down to about 30 amps. This 30 amps will
gradually taper down to 20a when there's 20ah to go, 10a when there's
10ah to go, etc. until it is almost zero amps when fully charged.
A sealed AGM has a lower internal resistance; they will draw 2 or 3
times this current.
> Using the motor as an inductor for the PWM - is that to smooth the
> square wave to an average V?
A PWM controller is a "buck converter", which is one of the fundamental
DC/DC converter circuits. It consists of 4 basic components; a
capacitor, an inductor, a transistor, and a diode.
But a typical PWM motor controller only has the transistor and diode;
the batteries serve as the capacitor (plus a small bank in the
controller), and the motor's field serves as the inductor.
If you use a PWM controller to drive something other than an inductive
load (for example, as a battery charger), then you need to add a
physical inductor. The purpose of this inductor is to act as a flywheel;
it stores energy during the transistor's "on" time, and gives it up
during the "off" time. Thus, the output current is relatively smooth.
Without the inductor, the current would be extremely large during the
"on" time, and zero during the "off" time. Worse, the controller's
current limit circuit wouldn't work; the transistor would be likely to
be destroyed.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Joe Smalley wrote:
> 1. If a pack is too small to run the car, then it holds too few
> kilowatt hours to move the car a reasonable distance...
> For instance, if the dump pack only holds 5 kilowatt hours,
> then it can only dump 4 kilowatt hours into the car if the
> dump charger is 80% efficient.
That's about right. And, it might be enough.
First, because you probably won't discharge the pack in your car more
than about 80% DOD (for good battery life). We'll assume you don't want
your dump charging pack to discharge any deeper, either. Charging
current efficiency is nearly 100%. This says the dump pack needs to be
roughly the same amphour capacity as the car pack.
Plus, the AC charger is probably on at the same time as the dump pack.
It will provide the extra energy to make up for charging current
efficiency being less than 100%.
> 2. The voltage sag of the donor pack during a dump charge will
> probably come down to about 10 volts per 12 volt block and the
> pack being charged would come up to nearly 15 volts per 12 volt
> block.
>
> For example, a 120 volt pack will need to come up to 150 volts
> during charge. You will need at least 160 volts into the
> controller to get this output if you budget for voltage drops
> in the current loop. Therefore you need 16 (12 volt) batteries
> to produce a good dump current.
It's not quite that bad, because we also have the AC charger to do the
high voltage finishing stage. This is done at relatively low current
over a relatively long time; so AC power is not the limiting factor.
I'd guess that the worst case is when the car pack is at 14.2v and
charging at a fairly high current (around 25% to 50% SOC). Add another
volt to allow for wiring, contactor, and controller voltage drops, and
we need 15.2v per 12v battery. Thus we'd need a 152v dump pack for a
120v car pack. Call it 156v for a standard multiple of 12v. So we have
13 dump batteries per 10 car batteries.
> 3. The higher voltage dump pack needs to have an ampere hour capacity
> AT THE DUMP CHARGE CURRENT as the battery being charged needs to
> absorb. This means the Peukert effect will take a big chunk out
> of the dump pack capacity.
It depends somewhat on whether you have a simple unregulated dump
charger (batteries basically in parallel), or one with a PWM controller
that is holding the current constant.
A simple dump charger won't stay at high current very long. Thus the
Peukert effect is reduced. You might only average 25 amps or so.
A regulated dump charger can hold the charging current constant despite
the varying battery voltages. It is more likely to also be used at a
much higher average current; hundreds of amps are not unthinkable. In
this case, Peukert effects in the dump pack *do* need to be taken into
account.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
