EV Digest 2844
Topics covered in this issue include:
1) Re: 1200A contactor?
by Gordon Niessen <[EMAIL PROTECTED]>
2) RE: 1200A contactor?
by [EMAIL PROTECTED]
3) Re: 72V dc/dc
by Lee Hart <[EMAIL PROTECTED]>
4) Re: Li Ion Series Resistance
by "Ralph Merwin" <[EMAIL PROTECTED]>
5) Re: DC to AC
by Lee Hart <[EMAIL PROTECTED]>
6) Re: !958 Chevy Truck Conversion
by David Dymaxion <[EMAIL PROTECTED]>
7) Re: article: Brits target electric speed record
by ItalysBadBoy <[EMAIL PROTECTED]>
8) Re: was over-priced EV on eBay/factory conversion.
by Sam <[EMAIL PROTECTED]>
9) Re: Starting torque
by Rich Rudman <[EMAIL PROTECTED]>
10) Re: Li Ion Series Resistance
by Lee Hart <[EMAIL PROTECTED]>
11) Re: DC to AC
by "1sclunn" <[EMAIL PROTECTED]>
12) Re: Starting torque
by Victor Tikhonov <[EMAIL PROTECTED]>
13) Re: article: Brits target electric speed record
by [EMAIL PROTECTED]
14) Re: Starting torque
by Victor Tikhonov <[EMAIL PROTECTED]>
15) Re: DC to AC
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Starting torque
by "Roderick Wilde" <[EMAIL PROTECTED]>
17) Pallet jack controller
by "The Levine Family" <[EMAIL PROTECTED]>
18) Re: DC to AC
by "Chuck Hursch" <[EMAIL PROTECTED]>
19) Re: Starting torque
by Victor Tikhonov <[EMAIL PROTECTED]>
20) Re: DC to AC
by Sheer Pullen <[EMAIL PROTECTED]>
21) RE: DC to AC
by "Tom Hudson" <[EMAIL PROTECTED]>
22) Why did the Optimas explode?
by Michael Hoskinson <[EMAIL PROTECTED]>
23) LiIons self-discharge rate
by Victor Tikhonov <[EMAIL PROTECTED]>
24) Re: Why did the Optimas explode?
by [EMAIL PROTECTED]
25) Re: DC to AC
by Peter VanDerWal <[EMAIL PROTECTED]>
26) Re: Li ion Cooling (Was: Li Ion Series Resistance)
by Ryan Fulcher <[EMAIL PROTECTED]>
--- Begin Message ---
Wow, same seller has a 48VDC/200amp PS for $200. Now that would charge
your batteries quick. Too bad shipping is almost as much as the purchase
price.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3309418213&category=undefined
At 12:52 AM 6/10/2003, you wrote:
This may have a 24V coil, but for what voltage are the contacts rated:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2536936098
--- End Message ---
--- Begin Message ---
For that amount of output you'd need to have a 50a 220vac circuit.
-----Original Message-----
From: Gordon Niessen [mailto:[EMAIL PROTECTED]
Sent: Tuesday, June 10, 2003 9:16 AM
To: [EMAIL PROTECTED]
Subject: Re: 1200A contactor?
Wow, same seller has a 48VDC/200amp PS for $200. Now that would charge
your batteries quick. Too bad shipping is almost as much as the purchase
price.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3309418213&category=undef
ined
At 12:52 AM 6/10/2003, you wrote:
>This may have a 24V coil, but for what voltage are the contacts rated:
>
>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2536936098
--- End Message ---
--- Begin Message ---
[EMAIL PROTECTED] wrote:
> Sounds good to me, where could I get 4-5 of these for $4.00 each?
This would be an astoundingly low price; pennies on the dollar. Either
the seller doesn't know the value of what he's selling, or he knows full
well and hopes the *buyer* doesn't! (i.e. it is junk, scrap, out of
spec, etc.)
There are several ways to look at this whole "surplus" situation.
First, there's the conservative "do it right the first time" approach.
Buy the best part for the job, even if it costs more. Buy based on
quality, performance, and correct fit:
- I spent serious money on my car, and don't want to wreck it
using substandard parts.
- I want it to be reliable, and last a long time.
- I want something that "just plain works".
- I don't have the time or experience to modify something that's
"close" so it will fit or work.
- I don't know which specs are important, and which ones I can
skimp on without affecting the end result.
Then, there's the hobbyist's approach. I'm doing this for fun, and to
learn. Money is the most important factor; everything else can suffer if
the price is right.
- I'm trying to do this as cheap as possible.
- Reliability is not important; if I fixed it once, I can fix
it again.
- I enjoy tinkering and modifying things to see if I can get
it to work better.
- I have plenty of time; no deadlines to worry about.
- I am a skilled technician or engineer, and know how it works,
and understand the tradeoffs and their consequences.
I use surplus parts a lot. You can find great deals if you know what
you're doing. EVs are a hobby for me, and I can't justify spending large
amounts of money on it. But, I also know a lot about the parts I'm
buying, how to use them, and their limitations. I also enjoy
experimenting and tinkering, to explore the limits of what works (and
what doesn't). And I still get stung sometimes; a part that looks great
turns out to be useless and a complete waste of money (even at 1 cent on
the dollar).
But I would not recommend using surplus for inexperienced or first-time
EVers, unless their financial situation is so bad that they have no
choice. If you don't know what you're doing, you can wind up buying
parts that are defective, or just plain won't work in your application.
Or, you get something that doesn't work right or has safety problems,
which you don't recognize due to inexperience.
In the case of the Henney, the original solution was a large enough 12v
accessory battery to cover the accessory loads, and an off-board 12v
charger to recharge it at the same time as the propulsion pack. It will
be easy to buy a good 12v battery and quality charger, so this solution
will work right away, and keep working for many years.
--
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 ---
John Lussmyer writes:
>
> Lee, I'm starting to setup my regs with temp sensors.
> Do you have any idea what size crimp terminal will take a TO-99 in the wire
> hole? (umm, urrgg, not sure if that is the right number. Same package as a
> 2N2222 transistor.)
John,
A 6ga terminal will probably be just a touch too small, so it might be
possible to spread the connector a little to fit the temp sensor. A 4ga
terminal will be too large but would allow you to epoxy the temp sensor
into the terminal, which is probably a better approach.
Try taking one of your temp sensors to the local hardware store for a
custom fitting.
Ralph
--- End Message ---
--- Begin Message ---
Mark Fowler wrote:
> I'm looking for an inverter that takes my DC pack voltage (144V DC)
> and turns it into 240V 50Hz AC (Australian mains current). The
> closest I've been able to find is combining a DC/DC (144V -> 12V)
> with a 12V to 240V inverter. I want to avoid massive 12V currents
> (and massive DC/DC) to get a decent amount of power from the
> inverter. Does such a beast exist? What sort of price?
What sort of load do you want to drive with this inverter? Does it need
to be a sinewave, or will a "modified sinewave" (i.e. square wave) be
good enough? How precise does the frequency have to be? What kind of
power level do you need (peak and continuous)?
--
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 ---
http://www.usbodysource.com
Prices may not be as bad as you think. They claim you can save 1500
pounds on a newer Chevy truck. They also have a kit where a replica
of an old truck goes on a minitruck chassis.
Disclaimer: No affiliation with US Body Source.
--- "Pestka, Dennis J" <[EMAIL PROTECTED]> wrote:
> Would like to do an old truck conversion.
> I'm looking at a 1958 - 1959 vintage Chevrolet.
> Would like reasonable performance instead of long range.
> Is this a good candidate for John Waylands high performance setup?
>
> Here are a few specs I have been able to get.
>
> Chevrolet Model 3104 Stepside Pickup
> 114" Wheelbase.
> 6.70-15 Tire Size.
> 3 speed manual transmission
> rear axle ratio of 3.90:1
>
> Weights:
> 3410# Curb Weight; 2015# Front 1395# Rear
> 5000# GVW
>
> 612# Engine and Clutch
> 65# Transmission
> 17.5 gal fuel tank
> 2" dia exh pipe.
>
> Other possible weight reduction could come with fiberglass body
> parts.
> They offer all parts for this vintage truck, but could become cost
> prohibitive.
> Just replacing the bed could shed ~ 300#, but at a cost of ~$2000.
>
> Is this vehicle a good choice, bad choice.
> I would like to do a pickup and have owned a few of these in the
> past.
> Thought it would be nice to do something different.
> I value any opinions or comments.
>
> Dennis
> Elsberry, MO
>
>
> > * LP8.2: HTML/Attachments detected, removed from message *
>
=====
__________________________________
Do you Yahoo!?
Yahoo! Calendar - Free online calendar with sync to Outlook(TM).
http://calendar.yahoo.com
--- End Message ---
--- Begin Message ---
* LP8.2: HTML/Attachments detected, removed from message *
--- End Message ---
--- Begin Message ---
--- Sam Thurber <[EMAIL PROTECTED]> wrote:
> Anything less than 10k would be a steal unless the
> batteries themselves are bad. If it has NiMH
> batteries, and they do take a charge, I would think up
> to 20k depending on the condition of the truck itself.
> If you don't buy it let me know :)
>
> -Sam
--- 1sclunn <[EMAIL PROTECTED]> wrote:
> He'd got the truck thinking that at worst he could put a gas engine
> back if it didn't work , it was a 1999 . >
>any Idea's on what it's worth?
> Steve Clunn
I would ask him where he got it. He may have picked it up from a county
or city auction, CHEAP. Judging from the statement above, knowing the
price he could have paid for an ICE 99' Ranger to begin with, it does
not stand to reason he would spend very much $ thinking "oh well, if it
doesn't't work I can always throw a gas engine in it".
Sounds like the owner of the Ranger and whoever sold it to him didn't
know what they really have/had. :)
Of course I could be way off base, but that is how it looks from
reading your post.
Sam Ruble
__________________________________
Do you Yahoo!?
Yahoo! Calendar - Free online calendar with sync to Outlook(TM).
http://calendar.yahoo.com
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
>
> Sorry, I don't have single motor working off of all 6 phases of
> Elfa. About launch torque - I'm not a racer, but I think objective
> is to be at finish line first, in as short time as possible.
> If launch is not as aggressive as for a DC system but from 500 RPM on
> it has advantage, overall you may be still better off.
>
> Tire smoke is good for spectators, but doesn't make you move
> quicker, and traction is your limit anyway. Just a thought.
>
> Victor
The guys with the degrees and the white lab coats miss this point rather
badly.
The launch end of the track is were you spend most of your time, that's
why you want to it leave as fast as you can.
And with the proper tire and suspension geometry, you launch instead of
burn rubber. Even with a single tire you can get a setup that won't spin
out.
The burn off is to heat the rubber so it sticks. Not just to measure our
Manhood by.
It's harder to make up lost time on the fast end it takes more Hp. Get
the lauch right, and keep the action going all the way down the strip is
the target.
Most of us EVers who spend a weekend or two a year racing soon realize
that the EV motors as we know and use them go to sleep at about 4000 to
5000 rpm. But off the line with a Series wound DC motor we can't get
enough traction to use the full power that we do make. Spin Stick... Bog
, Shift. AC offers full power from one line to the other, with enough
RPM range to get rid of the transmission.
With a light enough Chassis and years of effort, you can get a Dc motor
to run the length of the track and still yank it sideways at the MPH
trap. There is only ONE that has proven this.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
John Lussmyer wrote:
> Lee, I'm starting to setup my regs with temp sensors. Do you have
> any idea what size crimp terminal will take a TO-99 in the wire
> hole? (umm, urrgg, not sure if that is the right number. Same
> package as a 2N2222 transistor.)
The 2N2222 comes in at least half a dozen different packages. TO-99 is
an old 8-pin round metal can IC package. Perhaps you meant TO-92? That
is a 3-pin plastic cylindrical case with a flat size, and very common.
The TO-92 is 0.205" maximum diameter. A #6 crimp terminal is about 0.22"
diameter before crimping. I tried a few that I have, and it was an easy
fit. You might also try a #8 crimp terminal, but it may be too small;
some I had worked, and some didn't.
--
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 ---
I have been thinking about the same thing and was thinking of something like
a push pull audio amp and play a 60 or 50 cycle note into it . Yes there
would be some losses (60% i belive) but a nice clean sign wave , would
probable need 156v to get the 170 peak peak then a step up transformer .
with a H bridge ,maybe others have ideas.
----- Original Message -----
From: "Mark Fowler" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, June 10, 2003 4:32 AM
Subject: DC to AC
> Hi all,
>
> I'm looking for an inverter that takes my DC pack voltage (144V DC) and
turns it into 240V 50Hz AC (Australian mains current).
> The closest I've been able to find is combining a DC/DC (144V -> 12V) with
a 12V to 240V inverter.
> I want to avoid massive 12V currents (and massive DC/DC) to get a decent
amount of power from the inverter.
>
> Does such a beast exist?
> What sort of price?
>
> Mark
>
--- End Message ---
--- Begin Message ---
Joe Smalley wrote:
>
> The hard part is getting the impressive zero RPM torque to move the first
> car length out of a lightweight motor ...
I'd like to understand this better - what is it so critical about
first car length *provided* (let's assume for the moment), AC
machine with constant torque over most of its RPM range allows to
win the race. Wouldn't you rather be behind first couple car lengths
at start while guaranteed to get ahead at the finish?
AC advantages (no need to upshift) are clear for the most of the
track length, but not until few hundred RPMs, i.e.plenty of time to
catch up.
>... AND still pull big amps across the
> finish line.
I'm not expert here, but believe that drawing big amps isn't
the same as moving fast (although there is good correlation :-).
> Dennis can do both with DC. I'm still waiting for an AC machine
> to do it.
You'll be waiting until someone plunks money into it, it's not
a technical issue. Simulation for AC system shows expected
performance, but I have nothing to compare it with.
> They can do it at the finish line, but not at the starting line
> with the same hardware.
Important what they do in between too.
> Joe Smalley
> Rural Kitsap County WA
> Fiesta 48 volts
> NEDRA 48 volt street conversion record holder
> [EMAIL PROTECTED]
>
> ----- Original Message -----
> From: "The Levine Family" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Monday, June 09, 2003 7:53 PM
> Subject: Re: Starting torque
>
> > > AC convert, NO>>>>>>>>>>>>the potential to bypass and tweak is
> > to
> > > much fun!!~!! Dennis Kill A WATT Berube
> > 8
> > > sec qt.miles currenteliminator.net
> >
> > I'm sure *someone* in EV land can "tweak" an AC drive, it's just not as
> > easy - maybe more software than hardware?
> >
--- End Message ---
--- Begin Message ---
I realized that after I sent the last post.
Here is the first one I could find.
http://www.samincoinc.com/images/other_gallery.htm
Robert Salem
Columbus Ohio
> No pics huh?
>
> Allan
>
> [EMAIL PROTECTED] wrote:
> It will be interesting to see who does better !
> At least there is a date for the Ohio State Run.
>
> http://www.eng.ohio-state.edu/news/coe_news/archives/0210/021010_Bullet.html
>
> Go BUCKS !
>
> Robert Salem
> Columbus, OH
>
>
>
>
>
> > A new speed record attempt is going to be made.
> >
> > link to article:
> >
> > http://www.newcarnet.co.uk/newsarchiveitem.html?id=2795&pos=1
> >
> > --
> > Paul Wujek
> >
> >
> >
>
>
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> "For a successful technology, reality must take precedence over public
> relations, for Nature cannot be fooled." --- Richard P. Feynman
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Remember the following first rule of disinformation analysis: truth is
> specific, lie is vague. Always look for palpable details in reporting
> and if the picture is not in focus, there must be reasons for it.
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> ---------------------------------
> Do you Yahoo!?
> Free online calendar with sync to Outlook(TM).
--- End Message ---
--- Begin Message ---
Rich Rudman wrote:
>
> Victor Tikhonov wrote:
>
> It's harder to make up lost time on the fast end it takes more Hp. Get
> the lauch right, and keep the action going all the way down the strip is
> the target.
Ah, I see. What I'm saying (correct me if I'm wrong), if at launch
you're traction limited, you only can apply so much torque, AC or DC
system (same everything else - suspension, etc.). If either
system can give you that starting torque, there is no advantage
of either one; traction limited you move away just as quick.
So more-than-you-can-take-afvantage-of stall torque of DC
machine is no longer relevant (again if you got AC machine
with starting torque up to the traction limit).
Now, you move away and AC start showing advantages as soon as
you got to shift DC machine (not to spread comm bars all over).
Further you move - more pronounces advantage. Perhaps at
some point you upshift AC machine as well, but only once.
So overall with equal start but advantage in the middle,
I believe there is good chance for winning combo.
I still wish to model DC motor so to compare performance of
both system in identical setup vehicle.
Victor
--- End Message ---
--- Begin Message ---
1sclunn wrote:
> I was thinking of something like a push-pull audio amp and play a
> 60 or 50 cycle note into it. Yes, there would be some losses (60%
> I believe) but a nice clean sine wave, would probably need 156v
> to get the 170 peak peak then a step up transformer.
That's a clever idea. It might even work! :-)
Many years ago, when I first started experimenting with AC motor drives,
I used a 4-channel stereo amplifier as my inverter. It was an easy way
to produce 3-phase variable-voltage variable-frequency,
variable-waveform outputs. The amplifier was rated at 40 watts per
channel, which is about 18 volts into an 8-ohm load.
The first thing I learned was that audio amplifiers do not like
inductive loads. I got a lot of ringing and overshoot, which killed a
couple sets of transistors. Adding diodes to the + and - supplies solved
most of it. Changing capacitors and resistors in the amplifier's
feedback loops to smooth out its frequency response also helped.
I blew so many transistors that I relocated them to larger external
heatsinks, and replaced the TO-220 transistors with higher power TO-3
transistors in sockets.
Efficiency is poor when it is running in standard linear mode (class AB
as I recall). Efficiency improves if you overdrive it so it is working
as in switching mode (on/off), but then you obviously get square waves
out.
Yes, you could use the low-voltage audio output to drive a transformer,
to step the voltage up to any desired level.
So, if you didn't want very much power (less than 100 watts) and didn't
need the ultimate in efficiency, I think you could use an audio
amplifier with a switchmode power supply (so it will work with a DC
input) to generate 120vac.
--
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 ---
I concur with Rich on this subject. I believe Rich still remembers that run
in Phoenix in 1996 when we put the Mazda up against a specially prepared EV1
that had done 183 MPH. The GM dudes had just changed the gearing for drag
racing and thought no one could touch them. Out from the shade tree came the
little red Mazda. We lined up and when the lights dropped I must have been
asleep. I awoke to see the EV1 launch ahead of me. For those who have never
been to a drag race the Christmas Tree lights are a series of colored lights
on two sides of a post that turn on in sequence as they drop down the pole.
First is your staging light then Yellow, Yellow, Yellow then Green for GO!.
The next light after Green is RED. You get this light instead of Green if
you leave the starting line before the Green light. These lights are located
about 15 to 20 feet from the starting light. Now back to the story. When the
EVI launched ahead of me I nailed it and by the time we had reached the
Christmas Tree lights I had passed the EV1 like it was standing still. Rich
definitely remembers us later all screaming and chanting DC Rules, DC Rules!
from the stands. In a sense this was part of the beginning of NEDRA as we
all went to a pub and pizza place afterwards and discussed having a drag
racing organization.
Roderick
Roderick Wilde, President, EV Parts Inc.
Your Online EV Superstore
www.evparts.com
1-888-EV Parts (387-2787)
Phone: 360-385-7966 Fax: 360-385-7922
PO Box 221, 107 Louisa Street
Port Townsend, WA 98368
----- Original Message -----
From: "Rich Rudman" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, June 10, 2003 8:37 AM
Subject: Re: Starting torque
> Victor Tikhonov wrote:
> >
>
> > Sorry, I don't have single motor working off of all 6 phases of
> > Elfa. About launch torque - I'm not a racer, but I think objective
> > is to be at finish line first, in as short time as possible.
> > If launch is not as aggressive as for a DC system but from 500 RPM on
> > it has advantage, overall you may be still better off.
> >
> > Tire smoke is good for spectators, but doesn't make you move
> > quicker, and traction is your limit anyway. Just a thought.
> >
> > Victor
>
> The guys with the degrees and the white lab coats miss this point rather
> badly.
> The launch end of the track is were you spend most of your time, that's
> why you want to it leave as fast as you can.
>
> And with the proper tire and suspension geometry, you launch instead of
> burn rubber. Even with a single tire you can get a setup that won't spin
> out.
> The burn off is to heat the rubber so it sticks. Not just to measure our
> Manhood by.
>
> It's harder to make up lost time on the fast end it takes more Hp. Get
> the lauch right, and keep the action going all the way down the strip is
> the target.
>
> Most of us EVers who spend a weekend or two a year racing soon realize
> that the EV motors as we know and use them go to sleep at about 4000 to
> 5000 rpm. But off the line with a Series wound DC motor we can't get
> enough traction to use the full power that we do make. Spin Stick... Bog
> , Shift. AC offers full power from one line to the other, with enough
> RPM range to get rid of the transmission.
> With a light enough Chassis and years of effort, you can get a Dc motor
> to run the length of the track and still yank it sideways at the MPH
> trap. There is only ONE that has proven this.
>
> --
> Rich Rudman
> Manzanita Micro
> www.manzanitamicro.com
> 1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
I got this EV-T5 controller and contactors for a Clark pallet jack and I'd
like to know how I can use it - the contactors alone were worth the price,
but the controller might be useful if I knew its specs. I can't find
anything searching the web, so here are some pictures:
http://www.villagephotos.com/pubbrowse.asp?selected=305339
There are 12 control connections, of which 1, 3, 6, 7, 8, 10, and 12 have
pigtails, 2, 3, 4, 5, and 11 are wired into the contactor array, and 9 is
unused. The contactors have a couple lugs with bolts, a couple unused, and
another terminal that comes up in the middle of the copper bus connecting
the large contactor pair to one of the small ones.
I haven't opened up the end with the purple/brown/orange/yellow/pink QC
label, since I want to know what I can do with it before I try!
How much voltage and current *is* used by a pallet jack?
--- End Message ---
--- Begin Message ---
Mark Fowler wrote:
> I'm looking for an inverter that takes my DC pack voltage (144V
DC) and turns it into 240V 50Hz AC (Australian mains current).
> The closest I've been able to find is combining a DC/DC
(144V -> 12V) with a 12V to 240V inverter.
> I want to avoid massive 12V currents (and massive DC/DC) to get
a decent amount of power from the inverter.
>
> Does such a beast exist?
> What sort of price?
You might check Exeltech's line of inverters (I think it is
www.exeltech.com). They have several inverter models that run at
higher DC voltages. I had thought about one of these to run my
apt electrical loads off the Rabbit when the grid power goes out,
but unfortunately the closest inverter they have to my
96V-nominal pack is the 108V model, with low-voltage cut-off at
94V, so I'd have to be careful of the load. Would probably work
for a number of hours, however. This line of high-voltage input
inverters I recall being pure sine-wave, so that may be overkill
for your purpose. I imagine they can set up for 240VAC 50Hz.
Chuck Hursch
Larkspur, CA
NBEAA treasurer and webmaster
www.geocities.com/nbeaa
http://www.austinev.org/evalbum/339.html
www.geocities.com/chursch/bizcard.bmp
--- End Message ---
--- Begin Message ---
That was stock street EV1 (same motor/inverter/battery?), just
different gearing, and Mazda made for drag racing. What do you expect?
It might have been fun experiment to watch, but this outcome was easy
to predict ahead of time. And so this example really proves nothing in
AC vs. DC arena. It only proved that this particular EV1 was worse
than this particular Mazda, which, again, was obvious to begin with.
This is not to say one is better than other, we don't know until
someone does fair comparison. And, just because no one did it
yet (AC is new, expensive, whatever reason), doesn't mean that
technically other technology is better by default.
So of course DC still rules, but I believe it's because of vast
traditional past DC experience and no one seriously bothered yet to
try to do it differently. Time will tell.
Victor
Roderick Wilde wrote:
>
> I concur with Rich on this subject. I believe Rich still remembers that run
> in Phoenix in 1996 when we put the Mazda up against a specially prepared EV1
> that had done 183 MPH. The GM dudes had just changed the gearing for drag
> racing and thought no one could touch them. Out from the shade tree came the
> little red Mazda. We lined up and when the lights dropped I must have been
> asleep. I awoke to see the EV1 launch ahead of me. For those who have never
> been to a drag race the Christmas Tree lights are a series of colored lights
> on two sides of a post that turn on in sequence as they drop down the pole.
> First is your staging light then Yellow, Yellow, Yellow then Green for GO!.
> The next light after Green is RED. You get this light instead of Green if
> you leave the starting line before the Green light. These lights are located
> about 15 to 20 feet from the starting light. Now back to the story. When the
> EVI launched ahead of me I nailed it and by the time we had reached the
> Christmas Tree lights I had passed the EV1 like it was standing still. Rich
> definitely remembers us later all screaming and chanting DC Rules, DC Rules!
> from the stands. In a sense this was part of the beginning of NEDRA as we
> all went to a pub and pizza place afterwards and discussed having a drag
> racing organization.
>
> Roderick
>
> Roderick Wilde, President, EV Parts Inc.
> Your Online EV Superstore
> www.evparts.com
> 1-888-EV Parts (387-2787)
> Phone: 360-385-7966 Fax: 360-385-7922
> PO Box 221, 107 Louisa Street
> Port Townsend, WA 98368
>
> ----- Original Message -----
> From: "Rich Rudman" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Tuesday, June 10, 2003 8:37 AM
> Subject: Re: Starting torque
>
> > Victor Tikhonov wrote:
> > >
> >
> > > Sorry, I don't have single motor working off of all 6 phases of
> > > Elfa. About launch torque - I'm not a racer, but I think objective
> > > is to be at finish line first, in as short time as possible.
> > > If launch is not as aggressive as for a DC system but from 500 RPM on
> > > it has advantage, overall you may be still better off.
> > >
> > > Tire smoke is good for spectators, but doesn't make you move
> > > quicker, and traction is your limit anyway. Just a thought.
> > >
> > > Victor
> >
> > The guys with the degrees and the white lab coats miss this point rather
> > badly.
> > The launch end of the track is were you spend most of your time, that's
> > why you want to it leave as fast as you can.
> >
> > And with the proper tire and suspension geometry, you launch instead of
> > burn rubber. Even with a single tire you can get a setup that won't spin
> > out.
> > The burn off is to heat the rubber so it sticks. Not just to measure our
> > Manhood by.
> >
> > It's harder to make up lost time on the fast end it takes more Hp. Get
> > the lauch right, and keep the action going all the way down the strip is
> > the target.
> >
> > Most of us EVers who spend a weekend or two a year racing soon realize
> > that the EV motors as we know and use them go to sleep at about 4000 to
> > 5000 rpm. But off the line with a Series wound DC motor we can't get
> > enough traction to use the full power that we do make. Spin Stick... Bog
> > , Shift. AC offers full power from one line to the other, with enough
> > RPM range to get rid of the transmission.
> > With a light enough Chassis and years of effort, you can get a Dc motor
> > to run the length of the track and still yank it sideways at the MPH
> > trap. There is only ONE that has proven this.
> >
> > --
> > Rich Rudman
> > Manzanita Micro
> > www.manzanitamicro.com
> > 1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
On Tue, 10 Jun 2003, Lee Hart wrote:
> 1sclunn wrote:
> > I was thinking of something like a push-pull audio amp and play a
> > 60 or 50 cycle note into it. Yes, there would be some losses (60%
> > I believe) but a nice clean sine wave, would probably need 156v
> > to get the 170 peak peak then a step up transformer.
>
> That's a clever idea. It might even work! :-)
>
> Many years ago, when I first started experimenting with AC motor drives,
> I used a 4-channel stereo amplifier as my inverter. It was an easy way
> to produce 3-phase variable-voltage variable-frequency,
> variable-waveform outputs. The amplifier was rated at 40 watts per
> channel, which is about 18 volts into an 8-ohm load.
>
> The first thing I learned was that audio amplifiers do not like
> inductive loads. I got a lot of ringing and overshoot, which killed a
> couple sets of transistors. Adding diodes to the + and - supplies solved
> most of it. Changing capacitors and resistors in the amplifier's
> feedback loops to smooth out its frequency response also helped.
U'm, Lee, by definition audio amplifiers DO like inductive loads - what do
you think a speaker is ;0-)
However, they don't generally like inductive loads of the wrong
impedence. However, over the years, they've gotten a lot better - a lot of
the newest audio amplifiers will quite happily drive a sub-1-ohm load -
especially in 'bridged' mode.
> So, if you didn't want very much power (less than 100 watts) and didn't
> need the ultimate in efficiency, I think you could use an audio
> amplifier with a switchmode power supply (so it will work with a DC
> input) to generate 120vac.
seems kind of the painfull way round - if you're driving a power supply
anyway, why not just use one of the $30 inverters.
Audio amps would seem to be a neat way to prototype the power stage of a
inverter, though.
--- End Message ---
--- Begin Message ---
> I'm looking for an inverter that takes my DC pack voltage (144V
> DC) and turns it into 240V 50Hz AC (Australian mains current).
> The closest I've been able to find is combining a DC/DC (144V ->
> 12V) with a 12V to 240V inverter.
> I want to avoid massive 12V currents (and massive DC/DC) to get a
> decent amount of power from the inverter.
I had a similar unit built up by a gentleman named Chad Lampkin. It takes
my 156VDC from my Force and turns it into 120VAC at up to 15A. It has a
GFCI and everything. I would expect that Chad can build up a similar unit
for you.
I'm not sure how to reach him at present (I don't have an email address for
him) but you might contact Jerry Lilyerd ([EMAIL PROTECTED]) at Sun Energy
(http://www.sunenergyusa.com/), and he can probably get you in contact with
Chad. They work together.
-Tom
Thomas Hudson
http://portdistrict5.org -- 5th District Aldermanic Website
http://portev.org -- Electric Vehicles, Solar Power & More
http://portgardenclub.org -- Port Washington Garden Club
http://portlightstation.org -- Light Station Restoration
--- End Message ---
--- Begin Message ---
My friend Ken Norwick had some nasty experiences with YT's and if
anybody can explain what he might have done wrong it would
probably be educational for all. Ken is not a member of the
list. About a year ago he switched to flooded 8 volt USB
batteries and has had no trouble with them.
His car is a 96 Saturn with a 9" ADC motor and Raptor 600 amp
controller. He was using a Zivan NG3 charger. On 3 occasions he
had an Optima explode in a cloud of acid mist and loud noise.
These experiences had the undesirable side effect of reducing his
wife's tolerance of the project and any future EV efforts. For
some reason, she won't drive the car either.
As Ken described it, on each occasion the pack had recently come
off charge and he was within a block or two of starting out,
drawing less than full amps (he was not specific about the amps,
but I'd bet it was considerably less than, say Blue Meanie would
pull on an average demo run). Then BANG!, cloud of acid steam
and one of his batteries has no top. He told me that all of his
connections were good and it was not a question of melted posts.
Can anybody speculate on the cause of such a thing? I'm thinking
perhaps overcharging built up pressure in the batteries and extra
warming from current draw was enough to cause the explosion. But
what do I know? If there are questions I should be asking Ken,
please let me know.
Mike Hoskinson
ev-less in Seattle
--- End Message ---
--- Begin Message ---
Today I put my two 100Ah cells on the bench for testing my BMS. These
cells were initially working in ACRX in series with former YT pack.
Later (about 5 month ago) I disconnected them, planning to use
later for BMS testing and only now BMS is ready and I'm finding time
to actually try it, but I discovered that both cells have 0V on them.
Not even 0.01V, just dead 0V. These were never deaply cycled or
broken in properly, but experienced few (perhaps 10) shallow
charge-discharge cycles.
I don't know how properly broken in LiIons would have behaved
(I think, the same way), but this proves that several month
of no use self-discharges them to 0V I expected it to take longer.
According to Thunder-sky this is not harmful, it's just weird
to witness perfect new good battery with 0V on it.
I believe NiCds before decommissioning are somewhat similar - 0V
and those even recommended to be stored discharged with shorted
terminals.
Just a piece of real life info about LiIons.
Victor
--- End Message ---
--- Begin Message ---
I had one (1) twelve volt Douglas Marine deep cycle 105 amphr battery
explode one night as I shut off the DC circuit breakers between the
battery pack and controller. It was one of 20 batteries in series for a
240 volt DC battery pack to run a 230 volt DC 10 hp Westinghouse elevator
motor in my father's 1967 Ford Window Van. Douglas just said it was a
manufacturing defect, replaced the battery under warranty, and said I
would not be talking to them if it was not an isolated manufacturing
defect because otherwise all 20 would have blown up in my face.
Menlo Park III,
Bill
On Tue, 10 Jun 2003 17:59:33 -0600 Michael Hoskinson <[EMAIL PROTECTED]>
writes:
> My friend Ken Norwick had some nasty experiences with YT's and if
> anybody can explain what he might have done wrong it would
> probably be educational for all. Ken is not a member of the
> list. About a year ago he switched to flooded 8 volt USB
> batteries and has had no trouble with them.
>
> His car is a 96 Saturn with a 9" ADC motor and Raptor 600 amp
> controller. He was using a Zivan NG3 charger. On 3 occasions he
> had an Optima explode in a cloud of acid mist and loud noise.
> These experiences had the undesirable side effect of reducing his
> wife's tolerance of the project and any future EV efforts. For
> some reason, she won't drive the car either.
>
> As Ken described it, on each occasion the pack had recently come
> off charge and he was within a block or two of starting out,
> drawing less than full amps (he was not specific about the amps,
> but I'd bet it was considerably less than, say Blue Meanie would
> pull on an average demo run). Then BANG!, cloud of acid steam
> and one of his batteries has no top. He told me that all of his
> connections were good and it was not a question of melted posts.
>
> Can anybody speculate on the cause of such a thing? I'm thinking
> perhaps overcharging built up pressure in the batteries and extra
> warming from current draw was enough to cause the explosion. But
> what do I know? If there are questions I should be asking Ken,
> please let me know.
>
> Mike Hoskinson
> ev-less in Seattle
>
>
________________________________________________________________
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--- End Message ---
--- Begin Message ---
Wouldn't this be fairly easy to build? Assuming you can get by with a
modified sinewave (aka modified square wave) inverter. All you'd need
is an H-bridge and a transformer to step up the voltage. Well, that
and something to drive the H-bridge, but that should be fairly simple.
On Tue, 2003-06-10 at 04:32, Mark Fowler wrote:
> Hi all,
>
> I'm looking for an inverter that takes my DC pack voltage (144V DC) and turns it
> into 240V 50Hz AC (Australian mains current).
> The closest I've been able to find is combining a DC/DC (144V -> 12V) with a 12V to
> 240V inverter.
> I want to avoid massive 12V currents (and massive DC/DC) to get a decent amount of
> power from the inverter.
>
> Does such a beast exist?
> What sort of price?
>
> Mark
>
--
EVDL
--- End Message ---
--- Begin Message ---
humm, just a thought about cooling methods:
As you mentioned the terminal bolts get hot.
Because they are in direct contact with the heat source? and
Because they conduct heat much faster than the caseings?
How about heat sinking the terminal bolts?
Since each cell has two user accessable bolts,
perhaps removing the heat from the bolt would be a better
way than trying to remove it through the caseings? no?
Might be difficult to keep these "hot" (thermally and electrically)
heatsinks from shorting, but it might be worth looking into?
Other benefits, all the heatsink fins would be at the top of the pack.
(if the cells are all oriented with terminals facing up)
Passive and/or Active air flow accross the top of the pack could be
used, much simpler than liquid cooling I would imagine.
OH! HAY!! How about using the heat sink as the actual
connection between cells? See picture below.
top down ( x = heat sink / buss bars )
_______ _______ _______ _______
|xxxxxxxxxxxxx| |xxxxxxx... | |
|xx+xxxxxxx-xx| |xx+xxxx... | - |
|xxxxxxxxxxxxx| |xxxxxxx... | |
| | | | | | ... | |
|xxxxx| |xxxxxxxxxxxxx| ... | |
|xx-xx| |xx+xxxxxxx-xx| ... | + |
|xxxxx| |xxxxxxxxxxxxx| ... |_____|
cell1 cell2 cell3 ... cellx
side view ( single sink/bus bar )
( - and | is sink material, aluminum )
( = is conductive path, copper )
| | | | | | | | | | |
| | | | | | | | | | |
| | | | | | | | | | |
| | | | | | | | | | |
| | |bolt| | | | |bolt| | |
------ ----------- ------
---=== =========== ===---
L8r
Ryan
Lee Hart wrote:
Chris Brune wrote:
I did do a series discharge of four cells today at 27A. One cell
had a temp rise of about 30C. The whole block gets pretty warm.
Yes, I'm seeing that too. Notice that the terminal bolts get hotter yet,
indicating that the internal temperature is even higher.
--- End Message ---
