EV Digest 4145
Topics covered in this issue include:
1) RE: Slot Car Idea.
by "Myles Twete" <[EMAIL PROTECTED]>
2) RE: 3 phase PM-long and heading OT
by "Myles Twete" <[EMAIL PROTECTED]>
3) Re: Dave Cloud's Rules ideas
by James D Thompson <[EMAIL PROTECTED]>
4) SiC Schottkys
by Seth Allen <[EMAIL PROTECTED]>
5) RE: Dave Cloud's Rules ideas
by "Roger Stockton" <[EMAIL PROTECTED]>
6) Re: 3 phase alternator-why not an induction machine?
by Seth Allen <[EMAIL PROTECTED]>
7) RE: 3 phase PM-long and heading OT
by "Roger Stockton" <[EMAIL PROTECTED]>
8) Re: 3 phase alternator-why not an induction machine?
by James D Thompson <[EMAIL PROTECTED]>
9) Re: SiC Schottkys
by Rod Hower <[EMAIL PROTECTED]>
10) Re: Poll Re: Dave Cloud's Rules ideas
by "Joe Strubhar" <[EMAIL PROTECTED]>
11) Re: SiC Schottkys
by Seth Allen <[EMAIL PROTECTED]>
12) New EV Dragster
by [EMAIL PROTECTED]
13) Two Boost Options
by "Bill Dennis" <[EMAIL PROTECTED]>
14) RE: Does only size matter? (For DC motors?)
by "Markus L" <[EMAIL PROTECTED]>
15) Re: Slot Car Idea.
by Lightning Ryan <[EMAIL PROTECTED]>
16) RE: Power Transmission (was: Re: NEDRA rule changes)
by Jeff Shanab <[EMAIL PROTECTED]>
17) EV1 Vigilers -Day 15 Celebration and Media Update
by Marc Geller <[EMAIL PROTECTED]>
18) RE: 3 phase PM-long and heading OT
by "Peter VanDerWal" <[EMAIL PROTECTED]>
19) Warning sound for approaching EV
by "djsharpe" <[EMAIL PROTECTED]>
20) More EV crushing?
by Evan Tuer <[EMAIL PROTECTED]>
21) Re: Warning sound for approaching EV
by "Roland Wiench" <[EMAIL PROTECTED]>
22) RE: Warning sound for approaching EV
by "Adams, Lynn" <[EMAIL PROTECTED]>
--- Begin Message ---
> Implimentation Thoughts:
> How about a pair of embedded rails that could be driven over
> and synced up with. There could be multiple short segments such
One challenge: drivers don't like to stay in one lane very long when on the
road...especially the freeway.
--- End Message ---
--- Begin Message ---
Good points Peter-
> Using real PMDC motors as a generator/charger, with no
> external regulator, the only way to control current is by changing RPM.
As you say, no 12v battery charging current would flow from the ETEK
generator (thru a diode, or I'd use a transistor or mosfet for efficiency)
until the speed hit 990RPM, then WHAM---any increase in speed with the motor
will require more and more steam volume, and/or pressure. The pressure is
regulated at 70psi or so I think.
My guess is that from a control perspective it will be fairly stable.
This is because, as you say, no load will be presented until 990RPM or so,
then any increase goes into generated current and load, balancing the added
steam flow. Keep turning the steam up, the speed increases slightly, the
load current and torque increases and the speed stabilizes. Sure, as the
voltage rises, the current will drop---but that's not a problem---it, too,
is stable. The engine room guy can watch it periodically and increase the
speed to compensate. Ideally, the steam valve could be automatically
controlled by either output current, RPM or even by a modified 3-stage
charger used as a controller.
Thanks for raising a key point!
-Myles
--- End Message ---
--- Begin Message ---
>Also any vehicle in the claimer division can be purchased at the end of the
>race not just the winning vehicle. This still excludes the unclaimable
>division which no one can purchase ever.
What would probably happen in practice is that guys (and gals) in the same
money bracket would just swap cars around, which could be enjoyable in its
own way. Victor could show up at Woodburn and take the Zombie home that
night, while Wayland gets to play with AC motors and Hondas for a few
months.
David Thompson
--- End Message ---
--- Begin Message ---
I got mine free as samples. And I don't know what the replacement cost
was for the next few we got. I don't know what the qty 100 price is.
Seth
On Mar 1, 2005, at 8:56 PM, Rich Rudman wrote:
Yea Seth I read that PCIM issue also.
I did some checking and it's like $200 for a To-220 device. But the
specs
are too kill for.
It's clear these devices will revolutionize power silicon
archatechture.
But they are out of production and Cost range for now.
Put another way, When the get down to 2 times the cost of my
APT2X61D60s in
the Iso top TO-227 package.. I will install them in my chargers.
Yea Lee would be right using the Cree TO-220 package right now. And
they are
available, I just am NOT on the military procurement schedual.
----- Original Message -----
From: "Seth Allen" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, March 01, 2005 1:46 PM
Subject: Re: Question: Max efficiency charging with 3 phase alternator
Add a zero to that sixty volts, Rich. Cree makes 600V Schottky SiC
diodes. A spinoff of making all those blue LEDs...
How about that in a motor controller. Forward voltage drop still isn't
great, but they burn less power switching off.
Caveat Emptor on these, as I haven't used them (much at least), but
they are available in Otmar's favorite package, the TO-247.
Seth
On Mar 1, 2005, at 3:25 PM, Rich Rudman wrote:
OK Lee...
Schottkys can only be gotten up to about 60 volts, The voltage
spikes
ring
higher than that while boosting.
Good fets usually have good body diodes or are co-packed with better
diodes..
Yup... unless you can't use Schottkys then fets are your only choice.
I predicted a full Fet bridge was going to be better. Switching the
top
allows you to reduce rectification losses. A ON fet is a LOT lower
than
even a Schottky.
They staid with diodes on the top side. ...I think. We had long
arguments
about what was doable and what was right and cost effective. Yea to
do
topside sync rect they needed encoders,
Not cheap and easy. Doing this with BEMF sensing and a DSP...
Would...
allow for cheap commutation control.
Then again they didn't want to use a expensive Micro, they used a
MicroChip
of some sort.
So... there are ways to suck Trons from small sources... elegantly...
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, March 01, 2005 10:43 AM
Subject: Re: Question: Max efficiency charging with 3 phase
alternator
Rich Rudman wrote:
The best in the Buisness are PM windturbine power sections.
They use FETs and Diodes. The top of the 3 phase bridge is Diodes,
Low voltage, low conduction losses. Ultra fast soft recovery.
Who cares if they are fast or soft recovery? We're only dealing with
low
audio frequencies. I would think they would choose the diodes based
on
forward voltage drop (probably schottkys).
The bottoms are FETS that can be PWMed. This allows normal
rectification when there is enough windblowing.
Presumably by using the MOSFET's body diode? This is a high-drop
diode.
When there is not sufficient wind for conduction into the
Batteries,
but there is voltage, they switch the bottoms Fets as a boost
converter.
Clever.
Fet can be better than a diode, if switched properly.
True, but if they are using ~1v drop body diode and non-schottkys,
there
goes efficiency.
--
If you would not be forgotten
When your body's dead and rotten
Then write of great deeds worth the reading
Or do the great deeds worth repeating
-- Ben Franklin, Poor Richard's Almanac
--
Lee A. Hart 814 8th Ave N Sartell MN 56377
leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Ralph Merwin [mailto:[EMAIL PROTECTED] wrote:
> What I don't inderstand is why anyone would want to enter
> this type of race. What's the incentive? Do the racers win
> cash in each division?
Same reason they would want to enter any NEDRA race: to try to set a
world record in their class.
That is the only incentive to race under NEDRA rules presently, there
are no cash prizes, just glory.
I think the additional incentive that $$ classes adds is that you can
show up at the track knowing that you are racing against vehicles built
with similar constraints as you faced building yours.
Let's face it, where is the incentive for people to go out and build a
vehicle that would end up competing against Maniac Mazda, Gone Postal,
White Zombie or the KillaCycle in order to win a record when setting a
record is the only (official) reward one gets?
The only reason for singling these vehicles out is that they all happen
to be fairly high dollar undertakings that most hobbiests simply can't
compete with. We can't all get sponsorship from a battery company or
motor company, or controller company and this makes it difficult to
compete with teams that can afford multiple motors and controllers, or
batteries the rest of us can't.
I certainly think there is an obvious incentive to see if you can build
the quickest 120V conversion for $5k or less, for instance, vs seeing
that the 120V class record is held by a multi-motored, perhaps
multi-controllered vehicle that you simply cannot compete with on a $5k
budget and therefore not bothering to try.
I think people are mistakenly focusing of the 'claimer' portion of the
$$ classes suggestion rather than on the $$ classes themselves. The
'claimer' aspect is merely a way to encourage/ensure that people are
honest about the class they compete in. It isn't meant to add/remove
incentive.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Looks like a private club and not the right forum to me...
Seth
On Mar 1, 2005, at 10:28 PM, Dave wrote:
http://finance.groups.yahoo.com/group/LOCOMOTIVE/ ?
David C. Wilker Jr. USAF (RET)
Children need love, especially when they do not deserve it.
- Harold
S. Hulbert
----- Original Message ----- From: "Seth Allen" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, March 01, 2005 7:02 PM
Subject: Re: 3 phase alternator-why not an induction machine?
It is wandering off topic, but if you look at a BSFC map of a Diesel
versus gasoline, then it becomes clearer. Having built both series
and parallel with diesel, I can explain the ins & outs, but why don't
I do it offlist or in an appropriate forum if someone can identify
it.
Seth
On Mar 1, 2005, at 10:55 PM, Lee Hart wrote:
djsharpe wrote:
I cannot understand why the Toyota & Honda hybrids are not Diesels.
I think the Japanese automakers are more concerned with pollution
than
fuel economy -- so they use gasoline-electric hybrids.
The Europeans are more concerned with fuel economy than pollution --
so
they use diesels. To manage pollution, Europe chose to mandate
low-sulfur diesel fuel.
At some point, the two may well get together and produce
diesel-electric
hybrids, to get lower pollutin *and* fuel economy.
--
Ring the bells that you can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in
-- Leonard Cohen, from "Anthem"
--
Lee A. Hart 814 8th Ave N Sartell MN 56377
leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Myles Twete [mailto:[EMAIL PROTECTED] wrote:
> In my friend's steam gen case, for 40amps output into 13.2v,
> I'd estimate:
> Speed = (13.2+.040*40)*72RPM/v = 1066RPM
> Loss: 1.6v * 40a = 64watts
> Efficiency: 100* (13.2/14.8) = 89% (resistive losses only)
I think that you are overly optimistic here. You quote specs that
showed the E-Tec's peak efficiency to be 88-89% at 70A+ and 36-48V. The
efficiency decreases with voltage, as illustrated by the drop in peak
efficiency to "just" 86% at 70A and 24V. There is little hope of
getting 89% at 13.2V and 40A if the peak efficiency is only 86% at 24V
and 70A (PM motor efficiency drops far more rapidly at light load than
at high load).
The E-Tec is approximately a cheaper version of the LEM-200 motor, and
while LEMCO's site doesn't show performance data for the LEM-200 at 12V,
it does provide data for the slightly smaller LEM-170:
<http://www.lemcoltd.com/spreadsheets/170-126%2012v.xls>
and at 24V:
<http://www.lemcoltd.com/spreadsheets/170-127%2024v.xls>
Notice that at 24V the efficiency curve looks much like that of the
LEM-200 (broad efficiency peak at about 86% from 55-90A, and still above
83% at 120A), however, at 12V and 40A the efficiency is about 45% and
doesn't break 70% until 100A (and then peaks at less than 73%).
The E-tec might make a decent generator at 24V or higher, but I don't
think it is looking very good for 12V applications.
The LEM-130 doesn't look too bad:
<http://www.lemcoltd.com/spreadsheets/130-95%2012v.xls>
it hits almost 75% efficiency at 12V and 40A, however, if you think the
E-Tec is a pricey option, forget about this puppy! ;^> I think the one
on the floor of my office cost us about $900.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
>The Toyota Echo is very similar to the Prius; almost the same size, same
>shape, same engine; but no hybrid system.
That was approximately true for the old Prius; the new one is a bit
smaller than a mid-90s Camry.
David Thompson
--- End Message ---
--- Begin Message ---
These SiC diodes have really impressive reverse
recovery characteristics compared to Ultrafast high
voltage diodes, but you need to compare the Vf versus
temperature and current. I think these have a great
future, but for current devices and power levels their
performance is lots of hype. They need to handle much
more current before they look attractive for motor
drives. They are currently nice items for highly
efficient military applications, but they have much to
be desired for cost effective high current motor
drives. I guess this comparison somewhat parallels
EV's.
Rod.
--- Seth Allen <[EMAIL PROTECTED]> wrote:
> I got mine free as samples. And I don't know what
> the replacement cost
> was for the next few we got. I don't know what the
> qty 100 price is.
>
> Seth
>
>
> On Mar 1, 2005, at 8:56 PM, Rich Rudman wrote:
>
> > Yea Seth I read that PCIM issue also.
> > I did some checking and it's like $200 for a
> To-220 device. But the
> > specs
> > are too kill for.
> >
> > It's clear these devices will revolutionize power
> silicon
> > archatechture.
> > But they are out of production and Cost range for
> now.
> >
> > Put another way, When the get down to 2 times the
> cost of my
> > APT2X61D60s in
> > the Iso top TO-227 package.. I will install them
> in my chargers.
> > Yea Lee would be right using the Cree TO-220
> package right now. And
> > they are
> > available, I just am NOT on the military
> procurement schedual.
> >
> >
> > ----- Original Message -----
> > From: "Seth Allen" <[EMAIL PROTECTED]>
> > To: <ev@listproc.sjsu.edu>
> > Sent: Tuesday, March 01, 2005 1:46 PM
> > Subject: Re: Question: Max efficiency charging
> with 3 phase alternator
> >
> >
> >> Add a zero to that sixty volts, Rich. Cree makes
> 600V Schottky SiC
> >> diodes. A spinoff of making all those blue
> LEDs...
> >>
> >> How about that in a motor controller. Forward
> voltage drop still isn't
> >> great, but they burn less power switching off.
> >>
> >> Caveat Emptor on these, as I haven't used them
> (much at least), but
> >> they are available in Otmar's favorite package,
> the TO-247.
> >>
> >> Seth
> >>
> >>
> >> On Mar 1, 2005, at 3:25 PM, Rich Rudman wrote:
> >>
> >>> OK Lee...
> >>> Schottkys can only be gotten up to about 60
> volts, The voltage
> >>> spikes
> >>> ring
> >>> higher than that while boosting.
> >>>
> >>> Good fets usually have good body diodes or are
> co-packed with better
> >>> diodes..
> >>>
> >>> Yup... unless you can't use Schottkys then fets
> are your only choice.
> >>>
> >>> I predicted a full Fet bridge was going to be
> better. Switching the
> >>> top
> >>> allows you to reduce rectification losses. A ON
> fet is a LOT lower
> >>> than
> >>> even a Schottky.
> >>>
> >>> They staid with diodes on the top side. ...I
> think. We had long
> >>> arguments
> >>> about what was doable and what was right and
> cost effective. Yea to
> >>> do
> >>> topside sync rect they needed encoders,
> >>> Not cheap and easy. Doing this with BEMF
> sensing and a DSP...
> >>> Would...
> >>> allow for cheap commutation control.
> >>> Then again they didn't want to use a expensive
> Micro, they used a
> >>> MicroChip
> >>> of some sort.
> >>>
> >>> So... there are ways to suck Trons from small
> sources... elegantly...
> >>>
> >>>
> >>>
> >>>
> >>> ----- Original Message -----
> >>> From: "Lee Hart" <[EMAIL PROTECTED]>
> >>> To: <ev@listproc.sjsu.edu>
> >>> Sent: Tuesday, March 01, 2005 10:43 AM
> >>> Subject: Re: Question: Max efficiency charging
> with 3 phase
> >>> alternator
> >>>
> >>>
> >>>> Rich Rudman wrote:
> >>>>> The best in the Buisness are PM windturbine
> power sections.
> >>>>> They use FETs and Diodes. The top of the 3
> phase bridge is Diodes,
> >>>>> Low voltage, low conduction losses. Ultra fast
> soft recovery.
> >>>>
> >>>> Who cares if they are fast or soft recovery?
> We're only dealing with
> >>>> low
> >>>> audio frequencies. I would think they would
> choose the diodes based
> >>>> on
> >>>> forward voltage drop (probably schottkys).
> >>>>
> >>>>> The bottoms are FETS that can be PWMed. This
> allows normal
> >>>>> rectification when there is enough
> windblowing.
> >>>>
> >>>> Presumably by using the MOSFET's body diode?
> This is a high-drop
> >>>> diode.
> >>>>
> >>>>> When there is not sufficient wind for
> conduction into the
> >>>>> Batteries,
> >>>>> but there is voltage, they switch the bottoms
> Fets as a boost
> >>>>> converter.
> >>>>
> >>>> Clever.
> >>>>
> >>>>> Fet can be better than a diode, if switched
> properly.
> >>>>
> >>>> True, but if they are using ~1v drop body diode
> and non-schottkys,
> >>>> there
> >>>> goes efficiency.
> >>>> --
> >>>> If you would not be forgotten
> >>>> When your body's dead and rotten
> >>>> Then write of great deeds worth the reading
> >>>> Or do the great deeds worth repeating
> >>>> -- Ben Franklin, Poor Richard's Almanac
> >>>> --
> >>>> Lee A. Hart 814 8th Ave N Sartell MN 56377
> >>>> leeahart_at_earthlink.net
> >>>>
> >>>
> >>
> >
>
>
--- End Message ---
--- Begin Message ---
This doesn't interest me in the slightest - I show my truck, or car, but I
have no interest in drag racing anyway.
Joseph H. Strubhar
E-Mail: [EMAIL PROTECTED]
Web: www.gremcoinc.com
----- Original Message -----
From: "Christopher Robison" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, March 02, 2005 4:08 PM
Subject: Re: Poll Re: Dave Cloud's Rules ideas
> I would be willing to compete this way.
>
> The way I see it, there are two principle competing views about the value
> of one's efforts and the resulting value of the vehicle they've built.
>
> On the one hand, there's the view held by many who have posted on this
> subject that a dragster is an immutable expression of a particular
> builder's/designer's/team's skill, and is the result of enormous effort
> that produces a sense of attachment that is beyond monetary compensation.
> Also, the idea that the vehicle is a continuing testbed, and if it were
> "bought away" following a race, that much of that work would be lost or
> the effort of redoing what was done would be an undue burden.
>
> On the other hand, there's the opposing view that if you have
> appropriately factored the cost of your materials *and your labor* into
> the bracket you're racing in, then if your car is purchased at the end,
> you now have the resources to build another car. Having played a
> supporting role in the design and construction of a few EVs so far and
> currently in the early stages of the first project of my own, I can't
> imagine someone completing a vehicle and not feeling like there are
> aspects that could have been executed better. Money is a limiting factor
> for many of us in "doing it over again"; this seems like a great way to
> give someone with demonstrated talent the opportunity to perfect the skill
> of high-performance EV design.
>
> The end result is that instead of *one* really fast car making positive
> impressions at drag events, the world now has *two*.
>
>
> The only serious problem in fairness that I can see is the issue that was
> mentioned earlier of a wealthy person spending a lot of money on a car and
> then running it in a lower price bracket to buy the record. The only
> mitigation I can think of off the top of my head is to make the records
> periodic: a record for each bracket for each year, for example. This
> would also make sense when considering the changing value of money over
> time, and the changing value of components as manufacturing expands and
> horsepower [hopefully?] becomes cheaper.
>
> Of course, this pretty much implies that these records hold an auxiliary
> status to some other form of ranking or classification that can record
> permanent all-time records. Like, say, voltage.
>
> I think the current system is appropriate for what it's doing -- giving
> folks a goal to attain, to push the performance of EVs ever higher. I also
> think that a claimer system could help spread interest in EV drag racing
> as an activity. Perhaps they both have a place.
>
> --chris
>
>
>
>
> Roderick Wilde said:
> > I would like to take an informal poll to find out who on this list
> > would build an electric race car if we had "Claimer Rules" and they
> > wouldn't otherwise build one because of the voltage divisions. I
> > would like to find out how much actual interest there is in this.
> >
> > Roderick Wilde
> > NEDRA President
> >
> >
>
>
--- End Message ---
--- Begin Message ---
For motor drives when paired with IGBTs, which are slow when hard
switched, then you probably hit the nail on the head. But for power
conversion with a higher PWM frequency, then they start to make sense.
300V parts with some MOSFETs might be worth investigation for some
DC-DC converters or a motor that has a very high fundamental frequency
and not a lot of current.
Seeing as these are a year or two old, then I am curious to see what
happens in the next few years.
Still waiting for 3.0V ultracaps...
Seth
On Mar 2, 2005, at 10:24 PM, Rod Hower wrote:
These SiC diodes have really impressive reverse
recovery characteristics compared to Ultrafast high
voltage diodes, but you need to compare the Vf versus
temperature and current. I think these have a great
future, but for current devices and power levels their
performance is lots of hype. They need to handle much
more current before they look attractive for motor
drives. They are currently nice items for highly
efficient military applications, but they have much to
be desired for cost effective high current motor
drives. I guess this comparison somewhat parallels
EV's.
Rod.
--- Seth Allen <[EMAIL PROTECTED]> wrote:
I got mine free as samples. And I don't know what
the replacement cost
was for the next few we got. I don't know what the
qty 100 price is.
Seth
On Mar 1, 2005, at 8:56 PM, Rich Rudman wrote:
Yea Seth I read that PCIM issue also.
I did some checking and it's like $200 for a
To-220 device. But the
specs
are too kill for.
It's clear these devices will revolutionize power
silicon
archatechture.
But they are out of production and Cost range for
now.
Put another way, When the get down to 2 times the
cost of my
APT2X61D60s in
the Iso top TO-227 package.. I will install them
in my chargers.
Yea Lee would be right using the Cree TO-220
package right now. And
they are
available, I just am NOT on the military
procurement schedual.
----- Original Message -----
From: "Seth Allen" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, March 01, 2005 1:46 PM
Subject: Re: Question: Max efficiency charging
with 3 phase alternator
Add a zero to that sixty volts, Rich. Cree makes
600V Schottky SiC
diodes. A spinoff of making all those blue
LEDs...
How about that in a motor controller. Forward
voltage drop still isn't
great, but they burn less power switching off.
Caveat Emptor on these, as I haven't used them
(much at least), but
they are available in Otmar's favorite package,
the TO-247.
Seth
On Mar 1, 2005, at 3:25 PM, Rich Rudman wrote:
OK Lee...
Schottkys can only be gotten up to about 60
volts, The voltage
spikes
ring
higher than that while boosting.
Good fets usually have good body diodes or are
co-packed with better
diodes..
Yup... unless you can't use Schottkys then fets
are your only choice.
I predicted a full Fet bridge was going to be
better. Switching the
top
allows you to reduce rectification losses. A ON
fet is a LOT lower
than
even a Schottky.
They staid with diodes on the top side. ...I
think. We had long
arguments
about what was doable and what was right and
cost effective. Yea to
do
topside sync rect they needed encoders,
Not cheap and easy. Doing this with BEMF
sensing and a DSP...
Would...
allow for cheap commutation control.
Then again they didn't want to use a expensive
Micro, they used a
MicroChip
of some sort.
So... there are ways to suck Trons from small
sources... elegantly...
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Tuesday, March 01, 2005 10:43 AM
Subject: Re: Question: Max efficiency charging
with 3 phase
alternator
Rich Rudman wrote:
The best in the Buisness are PM windturbine
power sections.
They use FETs and Diodes. The top of the 3
phase bridge is Diodes,
Low voltage, low conduction losses. Ultra fast
soft recovery.
Who cares if they are fast or soft recovery?
We're only dealing with
low
audio frequencies. I would think they would
choose the diodes based
on
forward voltage drop (probably schottkys).
The bottoms are FETS that can be PWMed. This
allows normal
rectification when there is enough
windblowing.
Presumably by using the MOSFET's body diode?
This is a high-drop
diode.
When there is not sufficient wind for
conduction into the
Batteries,
but there is voltage, they switch the bottoms
Fets as a boost
converter.
Clever.
Fet can be better than a diode, if switched
properly.
True, but if they are using ~1v drop body diode
and non-schottkys,
there
goes efficiency.
--
If you would not be forgotten
When your body's dead and rotten
Then write of great deeds worth the reading
Or do the great deeds worth repeating
-- Ben Franklin, Poor Richard's Almanac
--
Lee A. Hart 814 8th Ave N Sartell MN 56377
leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Hello to the EV world,
The time has come to introduce ourselves as future players in the
Electric Vehicle arena. Many of you know us from our past association
with a great group of guys ... NetGain Technologies, LLC.
What was "almost" common knowledge was NetGain's 18 month association
with NASA, conducting in-vehicle testing of very large "Supercapacitors"
under a government research program. That testing taught us a heck of a
lot, but kept us away from the race track for two full seasons.
After the successful conclusion of the NASA research program, three of us
decided to pursue the aspects of EVs that are a lot less like work.
While NetGain is diligently working to improve what are already the best
electric motors on the planet - the WarP Motors - and developing other
areas of advanced EV technology, we decided to have fun.
We built a new Battery Powered Dragster - "Aggravated Battery".
Although it has not seen the track yet, we dream of good things. We are
anxious for the Chicago weather to break - ushering in the start of the
drag racing season here in the Midwest.
Meanwhile, we have taken it to a car show held once a year at McCormick
Place in Chicago. The International Show Car Association's "World of
Wheels". We are pleased to say it took a First Place award. We think
that is a great coupe, considering the fantastic vehicles on display. If
you have never been to one if the ISCA's car shows ... go! You won't
believe your eyes!
Want to cast your vote for an electric vehicle? Allstate Insurance
initiated a contest where you can vote for your favorite vehicle from the
Chicago "World of Wheels" car show.
Show Allstate that alternative fuel vehicles ARE part of mainstream
America by voting for our electric vehicle. The car that wins with the
most votes earns a $2,500 cash prize.
Click on this link to see our car’s profile page.
http://www.allstateautopride.com/details.php?image_id=211
Registration of a valid email address is required to vote. One vote
permitted per person per email address. Voting period ends March 12th.
We thank you for your vote. Of course, we live by the Chicago motto ...
vote early and vote often :)
As the race season progresses, we will keep the list advised of our
progress (and failures). Eventually we will have a web page up, showing
photos and general info about the vehicle and our guys.
Hope to see you trackside.
John Emde, Karl Klein and Kevin Zak
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I'm probably going to install a boost pack of BB600 Nicads along with my TS
cells and am considering two options, on which I wanted to get some
opinions:
1) Use a circuit like Doug Hartley designed, where the two packs are
connected via a Schottky diode at their positive terminals. The Nicad pack
is slightly lower in nominal voltage than the TS pack, so the Nicads kick in
only when the voltage sags on the TS pack (Doug posted some good
explanations of this on the list last fall, using TS and PbA).
2) Keep the two packs separate (tied together at negative, but separated at
positive), with the Nicad voltage higher than the TS, right up to the max.
voltage that the Curtis 1231C can handle. When extra power is needed, the
driver manually switches from one pack to the other via a dashboard switch.
BB600s were intended for high current draws to begin with, so this might
make sense and add some capacity, but at the expense of being manual vs.
automatic, and of not allowing sharing of the load between the Nicads and
the TS cells. Plus, of course, I'd be carrying around the extra Nicad
weight all the time, even when not using it.
First option probably still seems the best to me, but I wanted to see what
others thought.
I picked Nicads over PbA because, even though watering will be a minor
hassle, I've got a long uphill climb at the end of my daily commute. Lots
of power needed for about a 15-minute stint.
Bill Dennis
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Hi Mark,
thanks for the suggestion. I was wondering about
the voltage rating of the ADC 6.7" Motors. The A89-4001
for example is rated at 4.15 HP cont. at evparts.com
and 7.4 HP for 5 min.
So I assume the higher HP rating of this motor is
due to the air flow and the peak power I can get
from both motors should be roughly the same?
Markus
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] On Behalf Of Mark Thomasson
> Sent: Wednesday, March 02, 2005 4:33 PM
> To: ev@listproc.sjsu.edu
> Subject: Re: Does only size matter? (For DC motors?)
>
>
> Some things to think about:
> The air intake ports on the ADC will plug up with grass and
> dirt, air flow
> will be reduced, and the motor will overheat, unless you duct
> clean air in
> from about the deck.
> My 6.7 ADC is a 72 volt motor. If it's rated for 4 hp at 72
> volts, it's
> only good for 2 hp at 36 volts.
> You may have to change the gear ratio to get the same torque,
> since the
> speed-torque curves are probably different.
> If a tractor pull takes less than one minute, your GE motor
> can probably
> put out over 10 hp for that length of time without
> overheating. To get more
> power than you have now, consider raising system voltage to
> 48v or even
> higher (may need a new controller, or bypass contactor for
> full 48v to the
> motor armature). If cooling is an issue, add a forced air
> fan blowing on
> the motor, or even a water spray.
> Keeping your existing motor, fixing it, and upgrading the
> batteries/controller seems a more practical and cost effective way to
> improve performance than changing the motor to a 6.7 ADC. Mark T.
>
> ----- Original Message -----
> From: "Christopher Zach" <[EMAIL PROTECTED]>
> To: <ev@listproc.sjsu.edu>
> Sent: Wednesday, March 02, 2005 11:40 AM
> Subject: Re: Does only size matter? (For DC motors?)
>
>
> > I've thought about the 6.7 myself but the problem for me is
> that the ADC
> > motor is typically wired series, not shunt. The shunt motor in the
> > Elec-trak is great mainly because it can keep the tractor
> at a constant
> > speed while going level, up hills, and (more important) down hills.
> >
> > Kind of like a normal lawn tractor where the engine has a
> governor on
> > the butterfly valve of the carb and the throttle changes
> the bias of the
> > governor. Keeps speed constant up and down hills.
> >
> > Is it really just a 1hp motor?
> >
> > Chris
> >
> > Markus L wrote:
> > > .........................
> > > I'd like to beef up my elec-trak E20. It has a fully
> enclosed 36V DC
> > > motor, rated continuous at 1.2 HP (power curve see
> > >
> > > ..........................So I was
> > > thinking if I should rather try to get an ADV 6.7" rated at 4HP
> > > continuous.
> > > The GE motor is fully enclosed, which is good as the motor is
> > > mounted underneath the tractor where all the grass clippings and
> > > dirt fly around. The ADC is open, air cooled and also a
> bit shorter.
> > > ................ What I want is a beefy motor
> > > down there that can deliver lots of torque for small
> periods of time.
> > > (I would like to take it to a garden tractor pull at some time)
> > >
> > > What do you guys suggest? Should I get the existing motor
> fixed and
> > > invest another $100 or so into it or should I go with a new motor
> > > (prob. $400 or more) which may also give me more torque.
> .>
>
>
>
> --
> No virus found in this outgoing message.
> Checked by AVG Anti-Virus.
> Version: 7.0.300 / Virus Database: 266.5.6 - Release Date: 3/1/05
>
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Myles Twete wrote:
Implimentation Thoughts:
How about a pair of embedded rails that could be driven over
and synced up with. There could be multiple short segments such
One challenge: drivers don't like to stay in one lane very long when on the
road...especially the freeway.
Ya, but if it's a matter of having enough juice to get there or not
I don't think a BEV driver would mind spending a minute or two creeping
up a hill on the shoulder while stuffing some big amps into the pack.
.oO( It's just a nutty dream anyway, gassers just wouldn't get it )
L8r
Ryan
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Sam asked:
"...recently if it is possible to use a plasma arc to
power a free-floating (eg: magnetically suspended) rotor..."
The answer is Yes, but only in a pure vacuum ;-)
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Greetings all from the EV1 Vigil!
It's been over 2 weeks! And all 78 cars are safe- we vigilers believe
that's something to celebrate!
As for a media update,
An article came out in the Santa Monica Mirror today (print version
tomorrow) on Paul Scott, Chris Paine, Peter Horton
http://www.smmirror.com/volume6/issue38/ev_devotees_hold.asp
Woody Harrelson published a solicited piece on the vigil (and a former
Specialist you might be familiar with) in his website
www.voiceyourself.com
And, the Daily Breeze and KCET Life and Times stopped by the vigil
today. We're told the Daily Breeze should hit Sunday (John Bogert) and
Life and Times will be on Tuesday!
Thank you everyone for help with the updates!
the EV1 Vigilers
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>> Efficiency: 100* (13.2/14.8) = 89% (resistive losses only)
>
> I think that you are overly optimistic here. You quote specs that
> showed the E-Tec's peak efficiency to be 88-89% at 70A+ and 36-48V. The
> efficiency decreases with voltage, as illustrated by the drop in peak
> efficiency to "just" 86% at 70A and 24V. There is little hope of
> getting 89% at 13.2V and 40A if the peak efficiency is only 86% at 24V
Note: he said "Resistive losses only"
> The E-Tec is approximately a cheaper version of the LEM-200 motor, and
> while LEMCO's site doesn't show performance data for the LEM-200 at 12V,
> it does provide data for the slightly smaller LEM-170:
>
> <http://www.lemcoltd.com/spreadsheets/170-126%2012v.xls>
>
> and at 24V:
>
> <http://www.lemcoltd.com/spreadsheets/170-127%2024v.xls>
>
> Notice that at 24V the efficiency curve looks much like that of the
> LEM-200 (broad efficiency peak at about 86% from 55-90A, and still above
> 83% at 120A), however, at 12V and 40A the efficiency is about 45% and
> doesn't break 70% until 100A (and then peaks at less than 73%).
Note: the chart clearly states that figures are with brushes set in a
neutral posistion. Adjusting brushes for generator mode will improve
efficiency. Plus he is planning on running generator at 13-14 volts not
11-12 volts, this will also improve efficiency.
I believe that 80% on the Etek is very possible.
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A vehicle inspector warned that my EV (Diahatsu Charade) poses a risk to
pedestrians cyclists because it is too quite. It needs according to him
a continuous sound. I seek comments from other EV or hybrid users.
Perhaps we could amplify the sound the brush gear makes or replicate the
horn of a main line loco. What do you think?
David
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Sorry for the cross-posting. anyone know more about this?
[..]
<[EMAIL PROTECTED]> to electriccarsUK 3/2/05
In a secret car demolishing site in France (a breaker), the PSA
group has started demolishing between 300 and 400 hundred Saxos and
106 that have never been used. They take out the Ni-Cad batteries
(where do they go?) and they sell the rest at a very high price. Do
you remember the Think scandal? Ford would do the same thing to
these cars, but were stopped. Who can stop Citroën and Peugeot? Will
they ever be credible again? Are they going to the EVS21 in Monaco?
Will they still laugh at us there? Please contact media and - the
PSA group - we all need this to be known!!!
The news has been leaked from within the PSA system - top level and
top secret ...
[..]
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How about using a playing card pin to the spokes of the wheels. The cyclist
bike is too quiet too.
When I had my EV inspected, they said it needed this and some of that. I
said, look at the new VIN label that is on the door, that this vehicle in in
compliance with all federal standards which list all safety requirements for a
EV.
The inspector said OHHH, and that was that.
A State inspector cannot override the federal requirements or have you add
something to the vehicle, unless he is a expert engineer in that field.
For example, one time they wanted me to add bumpers to a very low sports car
that is 1 inch off the ground, which was manufacture that way. The whole car
is made out of carbon fiber and there is no frame member in the front of the
car and only engine transaxle in the rear.
The reason for a bumper is to reduce damage to the body panels. The bumper
would cost more than the body panels and it would provide a hazard to the car,
because it would have to be jack up high so a 5 foot long steel I-beam could be
welded under the car, dragging on the ground, which would make the car
unstable. I said only 100 of these were made, so the large vehicle productions
regulations is not required for a low volume production.
I think production has to be at 300 vehicles before it has to meet standard
federal specifications.
Roland
----- Original Message -----
From: djsharpe<mailto:[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu<mailto:ev@listproc.sjsu.edu>
Sent: Thursday, March 03, 2005 1:17 AM
Subject: Warning sound for approaching EV
A vehicle inspector warned that my EV (Diahatsu Charade) poses a risk to
pedestrians cyclists because it is too quite. It needs according to him
a continuous sound. I seek comments from other EV or hybrid users.
Perhaps we could amplify the sound the brush gear makes or replicate the
horn of a main line loco. What do you think?
David
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After three years I have yet to surprise anyone while driving the
electric car. The road noise of the tires on the road provides pleanty
of warning. If a noise was required, I suppost the Prius and some of
the new cars that are very quite when running at slow speeds would also
need some kind of noise....
Lynn Adams
See my 100% electric car at http://www.austinev.org/evalbum/379.html
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of djsharpe
Sent: Thursday, March 03, 2005 1:17 AM
To: ev@listproc.sjsu.edu
Subject: Warning sound for approaching EV
A vehicle inspector warned that my EV (Diahatsu Charade) poses a risk to
pedestrians cyclists because it is too quite. It needs according to him
a continuous sound. I seek comments from other EV or hybrid users.
Perhaps we could amplify the sound the brush gear makes or replicate the
horn of a main line loco. What do you think? David
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