EV Digest 6808
Topics covered in this issue include:
1) Re: Triangle wave generator
by Lee Hart <[EMAIL PROTECTED]>
2) Tesla to Sell ESS (Lithium Ion EV Battery Pack to you & me)
by "Martin Winlow" <[EMAIL PROTECTED]>
3) Re: Tesla to Sell ESS (Lithium Ion EV Battery Pack to you & me)
by [EMAIL PROTECTED]
4) Re: Triangle wave generator
by Lee Hart <[EMAIL PROTECTED]>
5) Re: Reality check, Re: Permanent magnet motor question
by Victor Tikhonov <[EMAIL PROTECTED]>
6) Re: Reality check, Let's quit the thread
by Victor Tikhonov <[EMAIL PROTECTED]>
7) Re: Best Conversion Vehicle
by Jerry McIntire <[EMAIL PROTECTED]>
8) Raptor 600 problem
by "Andrew A." <[EMAIL PROTECTED]>
9) Re: Reality check, Let's quit the thread
by Steve Peterson <[EMAIL PROTECTED]>
10) Re: Thanks a lot Monster Garbage. I'll bet someone is happy.
by "Jorg Brown" <[EMAIL PROTECTED]>
11) Electric motor for air conditioning or power steering
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
12) RE: How regen works
by "Dale Ulan" <[EMAIL PROTECTED]>
13) RE: Triangle wave generator
by "Dale Ulan" <[EMAIL PROTECTED]>
14) Re: Electric motor for air conditioning or power steering
by "Dustin Stern" <[EMAIL PROTECTED]>
15) AGNS to run for 168 Volt Record Tonight
by [EMAIL PROTECTED]
16) Boost converter motor controllers
by Jeff Major <[EMAIL PROTECTED]>
17) RE: How regen works
by "George Swartz" <[EMAIL PROTECTED]>
18) RE: How regen works
by "Eidson, Mark" <[EMAIL PROTECTED]>
19) RE: Main Contactor Ebay Search Criteria
by "England Nathan-r25543" <[EMAIL PROTECTED]>
20) RE: How regen works
by "George Swartz" <[EMAIL PROTECTED]>
21) RE: Best paint for Battery racks
by [EMAIL PROTECTED]
22) Re: Reality check, Let's quit the thread
by GWMobile <[EMAIL PROTECTED]>
23) Electric motorcycle review comming next week
by JS <[EMAIL PROTECTED]>
24) RE: Best Conversion Vehicle
by "Garret Maki" <[EMAIL PROTECTED]>
25) wktec hits israel, fitting motor to clutch
by [EMAIL PROTECTED]
26) Re: PIR June 29-30 EV drag racing?
by "Chuck Hursch" <[EMAIL PROTECTED]>
27) Re: PIR June 29-30 EV drag racing?
by Lock Hughes <[EMAIL PROTECTED]>
28) Re: AGNS to run for 168 Volt Record Tonight
by Jim Husted <[EMAIL PROTECTED]>
29) RE: How regen works
by "Dale Ulan" <[EMAIL PROTECTED]>
--- Begin Message ---
You're thinking, Phil; and that's good. You also have a positive
"can-do" attitude that will go a long way toward achieving success. I am
not trying to criticise; I am trying to provide constructive criticism
that will *help* you succeed. I've built many controllers and products
with microcomputers, and know some of the naive assumptions that get
made. I'm hoping others can learn from my experience.
(-Phil-) wrote:
Watchdogs mainly protect from software exceptions.
I agree. They don't do anything until *after* something has gone wrong.
The correct use of a watchdog is to convert a dangerous failure into a
safer failure (motor won't run at all instead of motor can't be stopped).
You don't want the watchdog to just reset the system, and let things
blithely go on -- that's what you'd do for the micro in a TV set or a
toy. You want it to *lock down* the system so it can't work any more
until the problem is fixed. The watchdog in a micro won't do this -- YOU
have to design the system to do this.
A properly designed support circuit makes the electrical environment
non-hostile. Electric cars are not as hostile as say an ICE with a 50kv
spark dancing around!
It's actually the *energy* being handled that determines the risk. A
normal ICE's ignition system has a high peak voltage, but the energy is
quite low. An EV handles thousands of times more electrical energy. It
often gets scattered about the car, too (batteries in front and back.
An AM radio is a fairly good noise detector. They work fine around ICE;
but often fail miserably around EVs. That should give you a hint of the
noise levels involved.
An EV is the worst environment I've ever had to deal with for electrical
noise -- no kidding!
You can install a separate supply for the MCU in an EV that's
galvanically isolated. That stops most of the problems.
It helps. But it doesn't stop noise that's radiated, capacitively
coupled, or inductively coupled. It doesn't keep noise out of systems
that have to be connected to the propulsion pack.
Most controllers on the market are now MCU based. There's a reason.
Sure! At the moment, it's the fashionable solution. It's the only
solution most people are taught, the only one they know, and the only
one they even try. It's the solution that companies can make the most
money from.
And that's fine. It's a perfectly good solution. I just want people to
remember that it's not the *only* solution. EVs are a special sort of
problem, and that often calls for different solutions. You can build a
controller with switches, or contactors, or SCRs, or discrete
transistors, or opamps, or digital gates. From the driver's perspective,
all can be made to work equally well. Which one you pick depends on the
circumstances; which technology do you know, what parts to you have
already, what are your performance expectations, etc.
To me designing with Op-Amps is much more difficult!
That's because you know micros, and don't know opamps. To a man with a
hammer, every problem looks like a nail. But there is still a place for
screws or glue.
If you use a driver IC, they can be scaled up with the MOSFETs as well.
More drivers, maybe even one per FET if need be.
You don't want to use one driver per MOSFET. If you do, you wind up with
the MOSFETs turning on/off at slightly different times. The one that
turns on first or turns off last gets hit with the *full* current all by
itself. Bang!
There are plenty to choose from. There are even some "power modules"
on the market that take TTL in and do their own driving.
If you're a novice, this is the best way to go. Someone who is good at
it has presumably designed that module so it will work. If you try to
build it yourself, there will be a learning curve.
I'm not suggesting someone go build a controller without having
extensive electronics experience. It's not a simple do-it-yourself
project, but it's far from impossible!
Right! It *can* be done!
The "fun" begins when a novice looks at the existing designs, and
assumes their designer was an idiot, and that all those parts aren't
necessary. :-)
I think a collection of us could work together on an open design, and
that would be a fantastic project!
It's a good idea, and we've discussed it before. It hasn't been done yet
because people come to realize that's it's a lot of work and costs a lot
of money; and so everyone wants "someone else" to do it. All chiefs, no
indians.
--
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 ---
An interesting development?
http://www.teslamotors.com/blog2/
MW
--- End Message ---
--- Begin Message ---
Martin> An interesting development?
Martin> http://www.teslamotors.com/blog2/
Yes, interesting, but I didn't interpret the blog to mean they'd be selling
their ESSes to you and me, but to other EV manufacturers. That's not to say
someone couldn't form a company to offer them retail, but I'm skeptical the
retail sales would come directly from TEG.
--
Skip Montanaro - [EMAIL PROTECTED] - http://www.webfast.com/~skip/
--- End Message ---
--- Begin Message ---
tt2tjw wrote:
If we are talking IGBT here (with a 15v turn on) and are using purpose
designed driver IC (VLA500 from Powerex) with its own internal DC-DC
to provide floating supply to driver the gate and with the driver ICs
mounted on a purpose designed board (Powerex BG2A) which includes
capacitors, diodes and 15v power supplies for each driver, then most
of the problems (except switching losses) are covered?
Yes, you're on the right track. A module looks expensive compared to a
dozen little devices in parallel, but it works and is all built and
debugged for you.
Likewise, a driver board looks expensive compared to homebrewing your
own, but again, it's all there and working.
If so it seems too easy, I thought PWM controllers were hard?
Do you think its the case that integrated driver circuits, driver boards
and dedicated power supplies are fairly recent so although PWM
controllers used to be hard they are becoming easier?
No; here again, the PWM control section isn't all that hard. There are
dozens, perhaps hundreds of circuits and chips that do it. They have
been around for many decades. I have practical PWM controller circuits
that use exactly one transistor and no ICs at all!
The industrial equipment market has had dozens of companies selling PWM
controllers, and the various subassemblies to build them for many, many
years. The problem (for hobbyists) has always been that they look
expensive, and hobbyists think they can "roll their own" much easier.
It seems to me (with no knowledge or experience) that the physical
aspects of a PWM controller, ie. weather proofing, cooling, bus bars
etc. are much harder than the IGBT drivers.
Yes, these are the problems that the modules don't solve for you.
Packaging, cooling, safety interlocks, interconnections, etc.
Building a controller is like building a house. It's a big job not
because any part of it is hard -- on the contrary, almost every single
bit of it can be done by unskilled labor with only a little guidance.
Building a house is hard because there are so many *different* jobs that
must be done, in the right order, and that all must fit together well.
--
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 ---
Lee Hart wrote:
That's why advertisements will say, "Our revolutionary new motor is
twice as efficient as any standard motor", hoping you will think it does
twice the work with the same amount of energy. Wrong!
Not to protect marketer's practices (in general I hate it as well) but
in your example they didn't mention work done by motors. Fact is, they
didn't. You're the one (people in general) who wrongly assumed it.
Yes, they may have worded it so that such assumption is natural for
uneducated Joe Average, but as long as they don't directly lie
(motors are 90% efficient while in fact they are 75%) I personally have
no big problem with that. I do feel for Joe who does though.
Twice as efficient motor *only* means twice as few losses, nothing more.
What would you suggest to marketing? Do you expect them to say
"Our revolutionary new motor is twice as efficient as any standard
motor, but don't be confused, it only does 10% more work!" ?
They are not going to define in small print what "efficient" means,
less losses or more work for the same input. I wish they did.
If a standard motor is 80% efficient and their motor is 90%, then it has
half the losses, but only does 10% more work for a given amount of
energy. They are "lying with statistics".
I see lack of data and definitions. I don't see lie.
If telling only half truth is lying, yes, everyone is lying.
Let's quit this thread shall we?
Victor
--- End Message ---
--- Begin Message ---
Claudio Natoli wrote:
Hello all,
Victor, iirc this isn't the first time this has come up on the EVDL.
Let's see if we can put it to bed this time :-)
Anyway you slice it, 99% is approximately 5% more efficient than
94%
Really? How do you figure? Is it because 94+5=99? I really want to
know.
No, it is because (99-94)/94 =~ 5%.
Do you agree that 95% efficient thing has twice as few losses as 90%
efficient?
If something is 100 watt input, at 90% efficiency it produces 90W
output. and 10W losses. If it's 95% efficient, it produces 95W output
(yes, just 5W more, about 5%, not twice) but has 5W losses.
5W is twice as little losses as 10W, so this gadget is TWICE as efficient.
This DOES NOT imply that it produces twice as much output work with
the same input (as Lee suggested I'm trying to say). In fact you're
absolutely right, it's ~5% more work, but we weren't debating output
work, we were discussing efficiency (losses) only.
Hope this clears the fog.
Kill the thread please.
Victor
--- End Message ---
--- Begin Message ---
Bob,
How does the 90-91 Civic Wagovan compare with the 92 Civic in your
estimation? Sedans just make no sense to me (with dogs, kids, and
sports equipment), and the Wagovan hardly weighs more.
Jerry
--- End Message ---
--- Begin Message ---
Hi guys,
I'm having some trouble with my Raptor 600. I'm
running a 120v system with a Kostov 9" motor, using
the stock inductive throttle sensor and no tach
sensor.
The problem is this:
I have everything wired up. When I power up the
controller, it does the self check, the green light on
the remote display comes on, and the main contactor
closes. When I step on the gas, it puts power to the
motor. It just doesn't have any power. I mean, we're
talking 10 mph MAX (floored) in second gear.
This is where it gets weird. There is almost no
voltage drop when I floor it, and it only draws ~50A.
I tried calibrating the max throttle setting, but no
matter what I do I can't get the yellow light to come
on. I can get some small changes in the amount of
power delivered by tweaking the current limit and max
throttle pots, but nothing serious.
And now it gets even weirder. I put the car up on jack
stands and tried running it up. Same results. No
power, no amp draw. The next thing we tried was
tweaking the max throttle pot while the motor was
running. When you turn the pot, it acts like a
throttle control, provided the motor is already
running. You can rev it up to 150+ amps and spinning
like crazy (no load) just by turning the pot.
If you set the pot to a setting where the motor revs
up, and then get off the gas, and back on, it acts
just like before the adjustment. Sluggish and all.
I don't have a clue what to make of it. I'm really at
a loss for ideas.
I've opened up the controller and looked for problems.
There is no smoke smell, there is very little
corrosion on anything, and I've checked both
calibration pots with a VOM. Everything checks out
fine.
Sorry for the long post. Anyway, any assistance would
be greatly appreciated.
Thanks!
Andrew
____________________________________________________________________________________Boardwalk
for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's
economy) at Yahoo! Games.
http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow
--- End Message ---
--- Begin Message ---
I sorta hate to add my voice to this, but the dictionary definition of
efficiency is "output/input"--I just went and looked it up to be sure.
Victor, you're focusing on *losses*. That, by definition, is not
*efficiency*. This is not to say that focusing on losses and comparing
one product's loss to another product's loss is not useful--it may well
be. But when you do that, you're not talking about efficiency per se
(according to the dictionary).
By the dictionary definition, one product would have to produce twice
the output (for the same input) to be called "twice as efficient". For
instance, 2/3 is twice 1/3.
If you wanted to say one product has half the losses of another product,
that's what you have to say--you can't say (as you're trying to) that
it's therefore twice as efficient--because that wouldn't match the
dictionary definition of "efficient". In other words, Victor, you're
absolutely correct when you say "5W is twice as little losses as 10W"
but you err when you go on to say "so this gadget is TWICE as
efficient."
--Steve (who really hopes he's helped, not hindered)....
On Wed, 2007-05-23 at 10:38 -0700, Victor Tikhonov wrote:
> Claudio Natoli wrote:
> > Hello all,
> >
> > Victor, iirc this isn't the first time this has come up on the EVDL.
> > Let's see if we can put it to bed this time :-)
>
> >>> Anyway you slice it, 99% is approximately 5% more efficient than
> >>> 94%
> >> Really? How do you figure? Is it because 94+5=99? I really want to
> >> know.
> >
> > No, it is because (99-94)/94 =~ 5%.
>
> Do you agree that 95% efficient thing has twice as few losses as 90%
> efficient?
>
> If something is 100 watt input, at 90% efficiency it produces 90W
> output. and 10W losses. If it's 95% efficient, it produces 95W output
> (yes, just 5W more, about 5%, not twice) but has 5W losses.
>
> 5W is twice as little losses as 10W, so this gadget is TWICE as efficient.
>
> This DOES NOT imply that it produces twice as much output work with
> the same input (as Lee suggested I'm trying to say). In fact you're
> absolutely right, it's ~5% more work, but we weren't debating output
> work, we were discussing efficiency (losses) only.
>
> Hope this clears the fog.
>
> Kill the thread please.
>
> Victor
>
--- End Message ---
--- Begin Message ---
On 4/25/06, John Norton <[EMAIL PROTECTED]> wrote:
On Tue, 25 Apr 2006 14:18, Lawrence Rhodes wrote:
> This is a comment I got from an EV wannabe.
You know, I felt the same way about turning a Mustang into a lawnmower -
no way now that I saw it on monster garage.
Me too. I thought women would be as good as men at building things,
assuming that's where their interests were, but now that I've seen two
(out of two) all-women teams on monster garage go down into defeat, I
know better.
On the other hand, I've learned that it should be possible to turn a
car into an airplane in under a week! Man, I've been working on my EV
way too long; that would be sooooo much cooler!
ps Is there any one of us who wouldn't fire Jesse in his first week,
if we were stuck working with him?
pps Wow, just realized how old this thread is. Ah, the wonders of
searching through mail when you have a multi-year archive of the ev
list.
--- End Message ---
--- Begin Message ---
Does anyone think that this motor will work to drive a power steering
pump or an AC pump?
http://www.e-motorsonline.com/emotors/viewproduct_dcm.php?catid=2&Pid=DC
M00116
--- End Message ---
--- Begin Message ---
A sepex or compound winding plus a shunt chopper makes regen easiest to do
in my opinion. Series motor regen without field reversal is difficult
Other than on an AC system, where regen is even easier - 'only software'.
-Dale
--- End Message ---
--- Begin Message ---
The guy who thinks he can take a PIC, a little 1amp gate driver IC, and
a dozen MOSFETS and build a controller will have a bucket full of dead
parts to show that it isn't as easy as it looks. But it's still good
experience -- he'll learn a lot along the way!
Been there, done that, bought the T-shirt. If you wanna do this,
use every snubbing capacitor shown in the application notes. I'd use
the Powerex intelligent modules and Cornell Dublier IGBT/MOSFET
snubber capacitor networks, exactly as shown in the app notes.
Don't try to use just any old capacitor. Use the ones for
the job.
I wouldn't even attempt it if I didn't have a 100 MHz + 'scope.
Slowly ramp the input voltage and current up and watch for little
'hairs' during the switching periods. That is oscillation that'll
kill MOSFET's and IGBT's. Most electrical engineers that have
built this sort of thing will test every stage separately, and
start with low power levels first. Get it working at 12 or 24
volts first, tame all parasitics, then ramp up, repeat taming
the parasitics, etc.
-Dale
--- End Message ---
--- Begin Message ---
That's cheaper and lighter than the one offer by ElectroAutomotive - or that
I've found anywhere else, as I've also been looking.
By the way have you seen the electric compressor units at
http://www.masterflux.com/ ?
Although I can't seem to get an email reply, they have some ideal units.
Dustin
On May 23, 2007, Dewey, Jody R ATC COMNAVAIRLANT, N422G5G wrote:
> Does anyone think that this motor will work to drive a power steering
> pump or an AC pump?
>
>
> http://www.e-motorsonline.com/emotors/viewproduct_dcm.php?catid=2&Pid=DC
> M00116
--- End Message ---
--- Begin Message ---
The Lawless Industries AGNS bike with Denis onboard will be be running
at Thompson Raceway tonight.
At stake is the 168 volt record of 12.49 seconds. This is quicker than
she has ever run and will be a tough one to crack.
It should be very close. Unfortunately she won't be joined by the
Electropolitan with her new motor field and timing setup. I took her
out for a test run to seat the brushes and twisted the driveshaft in
half like a pretzel. Jim, I'll send you a picture tomorrow. BTW I found
a tag on the Prestolite that says "Made in England" How apropos that it
ended up in a car made in the same place.
Shawn Lawless
________________________________________________________________________
AOL now offers free email to everyone. Find out more about what's free
from AOL at AOL.com.
--- End Message ---
--- Begin Message ---
Hi Lee,
Interesting approach. Using the motor field as the
boost inductor. But you may find some issues. Look
at the example. If it was a 12 amp rated 72 volt
series motor, then the fields would have about 50
times the loss, not to mention saturation. If it was
a 100 amp rated 72 volt motor, then at 12 amps
armature current it would be derated by a factor of 8.
I don't know the IR intended application, but on the
face of it, maybe not well suited for propulsion. The
bidirectional buck-boost converter with separate input
inductor might be the ideal way to go. I think that
is how you might classify the lastest Prius system
(but with AC motor).
Jeff
--- Lee Hart <[EMAIL PROTECTED]> wrote:
>
> The 1974 International Rectifier SCR Applications
> Handbook describes a
> controller of this type. They ran a standard 72v
> series traction motor
> from a single 12v battery. An SCR controller was
> used, configured as a
> boost converter. The motor's field winding was the
> boost inductor. The
> capacitors normally present at the controller input
> were across the
> motor armature. As a result, input ripple current
> was high, but motor
> ripple current was very low.
>
> The efficiency was low (about 70%) because the SCR's
> 1.5v drop and the
> freewheel diode's 1v drop were over 20% of the
> supply voltage. But it
> happily converted 12v at 100a into 72v at 12a.
> Interestingly, the series
> motor behaved almost exactly the same as it would
> with a conventional
> 72v pack and buck converter style controller. But
> since you could boost
> the motor voltage considerably above pack voltage,
> it allowed higher
> torques at higher speeds than a conventional
> controller.
>
> Such a controller might be promising with today's
> low drop MOSFETs and
> schottky diodes.
> --
> 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
>
>
____________________________________________________________________________________Boardwalk
for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's
economy) at Yahoo! Games.
http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow
--- End Message ---
--- Begin Message ---
Dale, On AC systems, in order to get full regen down to low speeds, you
must rectify the AC output to a DC bus, then apply a boost chopper to boost
voltage and get energy to flow into the battery. It seems that there is no
free lunch.
On Wed, 23 May 2007 10:55:14 -0600, Dale Ulan wrote
> A sepex or compound winding plus a shunt chopper makes regen easiest
> to do in my opinion. Series motor regen without field reversal is
> difficult
>
> Other than on an AC system, where regen is even easier - 'only software'.
>
> -Dale
--- End Message ---
--- Begin Message ---
For high voltage packs you may be able to run the AC right into a PCF-20
like battery charger and get regen down to a fairly low RPM. me
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of George Swartz
Sent: Wednesday, May 23, 2007 12:50 PM
To: ev@listproc.sjsu.edu
Subject: RE: How regen works
Dale, On AC systems, in order to get full regen down to low speeds, you
must rectify the AC output to a DC bus, then apply a boost chopper to
boost voltage and get energy to flow into the battery. It seems that
there is no free lunch.
On Wed, 23 May 2007 10:55:14 -0600, Dale Ulan wrote
> A sepex or compound winding plus a shunt chopper makes regen easiest
> to do in my opinion. Series motor regen without field reversal is
> difficult
>
> Other than on an AC system, where regen is even easier - 'only
software'.
>
> -Dale
--- End Message ---
--- Begin Message ---
Just curious what a capacitor across the main contacts would do as arc
suppression.
Nate
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: Tuesday, May 22, 2007 11:34 AM
To: ev@listproc.sjsu.edu
Subject: Re: Main Contactor Ebay Search Criteria
Steve Condie wrote:
> how hard is it to add blowout magnets?
Not easy when the contactor wasn't designed for it.
The fundamental problem with this contactor is that it only has a single
contact, like a relay; not two like a high-power contactor. Thus, it
doesn't have the spacing between the off-state contacts to sustain high
voltage. The contacts are physically large (good for high current), but
bad for adding blowout magnets (because stronger ones are required to
span the large horizontal distance).
It is designed from the ground up to switch high current at LOW
voltages. I think the only practical way to use it in a high-voltage EV
would be with several in series, all switched at the same time.
--
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 ---
When I worked on the BREDA articulated dual power buses with electric AC
propulsion by Westinghouse, I gained some practical experience. I initially
wondered why they had a DC chopper in the system. It was for electrical
braking. The shunt chopper boosted the rectified voltage off the inverse
diode three phase bridge. Energy is steered back to the trolley overhead,
or if not receptive, energy flows to braking resistor grids. The whole
system worked very well. However, it is very complex and expensive. I have
drawn some conclusions regarding battery EV's and AC versus DC propulsion:
Pro DC
1. Less expensive than AC
2. Can use bypass for ultimate efficiency (no semiconductor drops
and chopper is off)
3. Only one semiconductor drop in series with motor in chopper mode.
(AC has two drops in a full wave bridge configuration)
4. Lower voltage systems for DC (to use AC off the shelf motors, must
use high battery voltage with many cells)
5. Can use contactor/resistor/shunt field control, simple controllers
6. No difficult control loops or stability problems at zero speed.
Series motor in particular is perfect match for vehicle dynamics
Pro AC
1. No brushes, or brush voltage drop. AC traction motors more robust
slightly smaller and less weight than DC equivalents
2. More exciting for electronic types
3. Cost will come down as more systems are available and as technology can
be borrowed from machine controls, for which many are now AC.
--- End Message ---
--- Begin Message ---
The best paint is anything is better than nothing.
I had my battery racks out unexpectedly on the one occasion I had them out.
I had rustoleum primer and exterior paint on hand. I wire brushed the rack
and painted a few coats. If I made a big project of painting the rack,
I'd never get it back together. In 1-2 years, I'll add another coat of
paint. It's normal in a corrosive environment.
unless you're doing a 1st time build, time is critical.
putting the coroplast between the metal rack and the battery is also
important to cut down on leakage current
Ben
--- End Message ---
--- Begin Message ---
Someone should just ask the manufacturer exactly what they mean.
On Wed, 23 May 2007 11:38 am, Steve Peterson wrote:
I sorta hate to add my voice to this, but the dictionary definition of
efficiency is "output/input"--I just went and looked it up to be sure.
Victor, you're focusing on *losses*. That, by definition, is not
*efficiency*. This is not to say that focusing on losses and comparing
one product's loss to another product's loss is not useful--it may well
be. But when you do that, you're not talking about efficiency per se
(according to the dictionary).
By the dictionary definition, one product would have to produce twice
the output (for the same input) to be called "twice as efficient". For
instance, 2/3 is twice 1/3.
If you wanted to say one product has half the losses of another
product,
that's what you have to say--you can't say (as you're trying to) that
it's therefore twice as efficient--because that wouldn't match the
dictionary definition of "efficient". In other words, Victor, you're
absolutely correct when you say "5W is twice as little losses as 10W"
but you err when you go on to say "so this gadget is TWICE as
efficient."
--Steve (who really hopes he's helped, not hindered)....
On Wed, 2007-05-23 at 10:38 -0700, Victor Tikhonov wrote:
Claudio Natoli wrote:
> Hello all,
>
> Victor, iirc this isn't the first time this has come up on the EVDL.
> Let's see if we can put it to bed this time :-)
>>> Anyway you slice it, 99% is approximately 5% more efficient than
>>> 94%
>> Really? How do you figure? Is it because 94+5=99? I really want to
>> know.
>
> No, it is because (99-94)/94 =~ 5%.
Do you agree that 95% efficient thing has twice as few losses as 90%
efficient?
If something is 100 watt input, at 90% efficiency it produces 90W
output. and 10W losses. If it's 95% efficient, it produces 95W output
(yes, just 5W more, about 5%, not twice) but has 5W losses.
5W is twice as little losses as 10W, so this gadget is TWICE as
efficient.
This DOES NOT imply that it produces twice as much output work with
the same input (as Lee suggested I'm trying to say). In fact you're
absolutely right, it's ~5% more work, but we weren't debating output
work, we were discussing efficiency (losses) only.
Hope this clears the fog.
Kill the thread please.
Victor
www.GlobalBoiling.com for daily images about hurricanes, globalwarming
and the melting poles.
www.ElectricQuakes.com daily solar and earthquake images.
--- End Message ---
--- Begin Message ---
Just one line at the bottom of the page in the Los Angeles Times Highway 1:
"Throttle jockey: Columnist Susan carpenter is on assignment. Next week,
she reviews an electric motorcycle and gives her take
on the changes in store thanks to better batteries"
--- End Message ---
--- Begin Message ---
de gustibus non est disputandum
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Dan Whitley
Sent: Tuesday, May 22, 2007 4:30 PM
To: ev@listproc.sjsu.edu
Subject: Best Conversion Vehicle
I have been lurking for awhile and I too am considering an electric
vehicle. If the 914 is not the best convert then what is? I am not
a mechanic, so a kit sounds good to me!!!! Dan Whitley
--- End Message ---
--- Begin Message ---
hi everybody
wktec finally got shown here (israel) in an eco-cinema festival.
pretty interesting stuff, i loved the bits of stan and iris
ovshinsky and whoever the controller-builder geeky guy
with the huge smile is (the subtitles block peoples names).
until i actually meet any evlist people in person , that
guy is the mental image i associate with the list.
was amazed to learn that reagan actualy pulled pv cells off the
white house that carter installed, and that a hummer
gets a max $100k tax break!?$?
some questions:
in light of recent discussions on direct-drive vs non,
(the parts before the OED semantic analysis)
it looks like i will keep my gears and therefore clutch.
so i need to machine some doodad that hooks my ac42 motor
to the clutch. I guess the easiest is to machine a piece that looks
like that part of the engine that bolts to the clutch on one side,
and fits my motor on the other.
from aluminum plate?
the donor car is a suzuki alto.
any advice appreciated
thx
jeremy
--- End Message ---
--- Begin Message ---
Jim,
Maybe you should set it up so that when the car does its initial
lift at launch, there's some kind of insanely scary zombie image
that fluoresces off the motor, kinda like from your worst
nightmare movie, to run chills up and down the spine of the guy
in the other lane and the audience too. Just an evil thought...
I'll try to keep track of where you guys are at. Best of luck on
getting the motors back together and getting everything up and
running. I'd like to see WZ do an 11-sec 1/4 the night I'm
there. That would be a nice touch for the Portland trip.
Chuck
----- Original Message -----
From: "Jim Husted" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, May 22, 2007 5:57 PM
Subject: Re: PIR June 29-30 EV drag racing?
> Hey Chuck
>
> White Zombies motors are actually sitting at the shop
> right now under a morge sheet. John and Tim gave the
> back half a good fry earlier this year so she's down
> for repair. I wasn't able to pop it apart today but
> the back armature looks really pissed so they got it
> good.
>
> While it's down we're gonna upgrade it with some added
> changes. At this point I'm thinking I'm gonna be
> popping the Ka-Bobs off that shaft and replacing the
> rear one. In as much as it sucks I'll be able to
> glean some data as to how everythings been holding up,
> like the middle bearing etc.
>
> I'd like to send this out to the paint shop and have
> them airbrush some cool peeled paint revealing a
> Zombie textured motor or something. What you say John
> you up for a little artisic touch on this build Mr.
> magizine?
>
> Anyway at this point all I can say is I'll get it back
> to John as fast as I can. The biggest plus is I got
> the shaft 8^o so now it's a bit of how much more does
> Wayland want to change.
>
> Anyway Chuck, sorry to be the one to tell you but
> those evil bastards killed my motor 8..^(
>
> Good thing it's a Zombie though cause they just keep
> rising from the dead 8^) hehe.
> Had fun
> I'll keep you all posted.
>
> Jim Husted
> Hi-Torque Electric
>
>
>
>
>
>
_________________________________________________________________
___________________Pinpoint customers who are looking for what
you sell.
> http://searchmarketing.yahoo.com/
>
--- End Message ---
--- Begin Message ---
hehe
...or a Jacobs Ladder maybe
http://www.mail-archive.com/[EMAIL PROTECTED]&q=jacobs+ladder
...see also the Hollywood Tesla "light shows" from the 2006 movie "The
Prestige".
tks
Lock
Toronto
human-electric hybrid
--- Chuck Hursch <[EMAIL PROTECTED]> wrote:
> Jim,
> Maybe you should set it up so that when the car does its initial
> lift at launch, there's some kind of insanely scary zombie image
> that fluoresces off the motor, kinda like from your worst
> nightmare movie, to run chills up and down the spine of the guy
> in the other lane and the audience too. Just an evil thought...
>
> I'll try to keep track of where you guys are at. Best of luck on
> getting the motors back together and getting everything up and
> running. I'd like to see WZ do an 11-sec 1/4 the night I'm
> there. That would be a nice touch for the Portland trip.
>
> Chuck
>
> ----- Original Message -----
> From: "Jim Husted" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Tuesday, May 22, 2007 5:57 PM
> Subject: Re: PIR June 29-30 EV drag racing?
>
>
> > Hey Chuck
> >
> > White Zombies motors are actually sitting at the shop
> > right now under a morge sheet. John and Tim gave the
> > back half a good fry earlier this year so she's down
> > for repair. I wasn't able to pop it apart today but
> > the back armature looks really pissed so they got it
> > good.
> >
> > While it's down we're gonna upgrade it with some added
> > changes. At this point I'm thinking I'm gonna be
> > popping the Ka-Bobs off that shaft and replacing the
> > rear one. In as much as it sucks I'll be able to
> > glean some data as to how everythings been holding up,
> > like the middle bearing etc.
> >
> > I'd like to send this out to the paint shop and have
> > them airbrush some cool peeled paint revealing a
> > Zombie textured motor or something. What you say John
> > you up for a little artisic touch on this build Mr.
> > magizine?
> >
> > Anyway at this point all I can say is I'll get it back
> > to John as fast as I can. The biggest plus is I got
> > the shaft 8^o so now it's a bit of how much more does
> > Wayland want to change.
> >
> > Anyway Chuck, sorry to be the one to tell you but
> > those evil bastards killed my motor 8..^(
> >
> > Good thing it's a Zombie though cause they just keep
> > rising from the dead 8^) hehe.
> > Had fun
> > I'll keep you all posted.
> >
> > Jim Husted
> > Hi-Torque Electric
Get a sneak peak at messages with a handy reading pane with All new
Yahoo! Mail: http://mrd.mail.yahoo.com/try_beta?.intl=ca
--- End Message ---
--- Begin Message ---
Hey Shawn
Well wishing ya the best with AGNS tonight. I take it
you passed this weeks class of Hi-Torques online
school of Motor mods 101? Is the Mrs. pissed at us or
chomping on the bit to take it out now? I guess
she'll be doing more than 50 at the 1/4?.
Give me a write, can't wait to hear all the juicy
tidbits..
I know you got your hands full but I'll be waiting for
the final report, it's 90% of the grade, hehe.
BTW I told you it was built in England 8^)
Anyway get that coathanger of a driveshaft replaced
and go torment some teenagers with the little sleeper.
Cya
Jim Husted
Hi-Torque Electric
--- [EMAIL PROTECTED] wrote:
> The Lawless Industries AGNS bike with Denis onboard
> will be be running
> at Thompson Raceway tonight.
> At stake is the 168 volt record of 12.49 seconds.
> This is quicker than
> she has ever run and will be a tough one to crack.
> It should be very close. Unfortunately she won't be
> joined by the
> Electropolitan with her new motor field and timing
> setup. I took her
> out for a test run to seat the brushes and twisted
> the driveshaft in
> half like a pretzel. Jim, I'll send you a picture
> tomorrow. BTW I found
> a tag on the Prestolite that says "Made in England"
> How apropos that it
> ended up in a car made in the same place.
>
> Shawn Lawless
>
________________________________________________________________________
> AOL now offers free email to everyone. Find out
> more about what's free
> from AOL at AOL.com.
>
>
____________________________________________________________________________________Yahoo!
oneSearch: Finally, mobile search
that gives answers, not web links.
http://mobile.yahoo.com/mobileweb/onesearch?refer=1ONXIC
--- End Message ---
--- Begin Message ---
When I worked on the BREDA articulated dual power buses with electric AC
propulsion by Westinghouse, I gained some practical experience. I initially
wondered why they had a DC chopper in the system. It was for electrical
braking. The shunt chopper boosted the rectified voltage off the inverse
....
That's interesting. But a lot of ACIM controllers do not have a separate
regen circuit - the boost function is only done via software control of
the 6-pack in the right manner...? Perhaps into a trolley wire it needs
different control than to a battery pack? Actually, that makes sense.
The trolley wire interface needs to work with bad connections and
a battery-driven unit does not.
At low speeds the regen might go away, maybe Victor or other AC
users can chime in? All of my EV experience (and motor control
design and repair) have been in BLDC's and they regen nicely to
low speeds (just about stopped) just using the 6-pack as their
boost converter.
-Dale
--- End Message ---
