EV Digest 5026
Topics covered in this issue include:
1) Re: Loading wrong frequency (was RPM matching)
by Lee Hart <[EMAIL PROTECTED]>
2) Re: Clutchless shift with rpm-matching?
by Lee Hart <[EMAIL PROTECTED]>
3) Re: potbox without a pot?
by Lee Hart <[EMAIL PROTECTED]>
4) Re: EV acceptance idea
by Lee Hart <[EMAIL PROTECTED]>
5) Pics of a Sunrayce 95 vehicle
by Ryan Stotts <[EMAIL PROTECTED]>
6) Re: Capacitors
by mike golub <[EMAIL PROTECTED]>
7) MG Challenge.
by "Rich Rudman" <[EMAIL PROTECTED]>
8) Re: potbox without a pot?
by James Massey <[EMAIL PROTECTED]>
9) Re: MG Challenge.
by [EMAIL PROTECTED]
10) Re: MG Challenge.
by keith vansickle <[EMAIL PROTECTED]>
11) RE: RPM, brushes and commutators, was: RE: CVT transmission for E
V
by "Dewey, Jody R ATC (CVN75 IM3)" <[EMAIL PROTECTED]>
12) Re: EV acceptance idea
by keith vansickle <[EMAIL PROTECTED]>
13) RE: Festiva or Metro
by keith vansickle <[EMAIL PROTECTED]>
14) RE: pulleys question
by "Dewey, Jody R ATC (CVN75 IM3)" <[EMAIL PROTECTED]>
15) RE: Festiva or Metro
by Bob Bath <[EMAIL PROTECTED]>
16) RE: I want to build a PWM DC motor controller
by "Dewey, Jody R ATC (CVN75 IM3)" <[EMAIL PROTECTED]>
17) Re: RPM, brushes and commutators, was: RE: CVT transmission for EV
by "Roland Wiench" <[EMAIL PROTECTED]>
18) Re: I want to build a PWM DC motor controller
by "Mark Hanson" <[EMAIL PROTECTED]>
--- Begin Message ---
Victor Tikhonov wrote:
> Thanks Lee. You didn't have to go so much in depth of basics, but
> I guess it would benefit many on the list.
Since the question was asked in a public forum, I figured the answer should
also be general enough so most readers can understand it.
> Effect of going "out of phase" can be easily demonstrated by
> unplugging starting capacitor of single phase appliance AC motors:
> it will hum but not move - if you spin it in any direction,
> it will pick up the speed and rotate, but with little
> torque, you may be able to "stall" it by hand.
Yes, that's a good way to observe it. The motor will have very little torque
until it gets close to synchronous speed.
If it was a synchronous motor, it has essentially *zero* torque at anything
but full speed. A pure synchronous motor can't even start itself.
> The question was about a particular circumstances where you totally unload
> 3 phase the motor in order to shift, so no load.
Not quite. You still have the inertial load of the rotor, flywheel, clutch,
and related parts. Since the frictional loss is almost zero with the clutch
disengaged, this can actually be a worst case condition -- you are *more*
likely to have spring-mass oscillations when there is zero frictional load,
just as an electrical circuit is most likely to oscillate with inductance,
capacitance, and almost no resistance.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Cor van de Water wrote:
> I do not understand why everyone is so fixed on frequency control,
> as to my opinion there is only one parameter that is of importance
> to a smooth AC motor control: phase.
You can control based on frequency, or phase, or half a dozen other parameters
(rpm, back emf, torque, current, etc.) Which one you pick depends on the goal
of the control system.
For a traction drive, the driver is generally trying to control speed. In an
AC motor, speed is directly proportional to frequency. So, designers focus
the control system in the inverter on frequency.
But as you say, phase is a better control parameter. The controller adjusts
frequency and voltage to achieve a particular phase angle between the applied
voltage and back emf. This will have the effect of holding the motor fairly
close to the optimum voltage needed to achieve a high power factor and good
efficiency.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
James Massey wrote:
> It measures 4.5 ohms, and when I 'jit' the throttle arm back and forward it
> affects the reading as I'd expect from an inductor in a magnetic field...
> should have measured it before posting yesterday). So there is an [apparent]
> inductor sitting in a pair of magnetic fields, one for the throttle request,
> the other from the traction cable as feedback.
An iron core inductor with no magnets around is symmetrical. If you build an
oscillator with this inductor, it will have a 50% duty cycle.
If you bias it with a magnet, the core will saturate easier in one direction.
Its inductance for positive current will be different than for negative
current. If you build an oscillator with this coil, its duty cycle will be
assymetrical.
Thus, their circuit could be looking at the duty cycle of an LC oscillator's
waveform to determine the position of the magnets, and thus the throttle
position.
> Now one of the things that Lansing Bagnall did is to build up the control
> circuit of their SCR controllers with a bunch of plug-in modules --
> multivibrator, pulse selector, pulse shaper, trigger circuit, con. hold
> circuit. Each in their own module, a little bigger than a matchbox,
> plugging into a set of sockets.
Cute; like home-made integrated circuits. :-) I wonder if they did this for
easier serviceability, or to allow rapid customization for different customer
requirements.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
paul wiley wrote:
> EV's will never be popular even if they got 300+ miles to the charge.
You know, people don't live forever. New generations keep coming in to replace
the old ones. When they do, they have entirely new perceptions.
My parents grew up in the 1950's with Big American Iron. To this day,
full-size American cars are "normal" to them. It's what they drive, and what
they like. They think little cars are dangerous, and big SUVs are
uncomfortable trucks.
I grew up in the 70's, when small cars became commonplace. Small, nimble,
efficient, lower-polluting cars are "normal" to me. The old land yachts and
newer SUVs strike me as pointlessly huge, awkward, and wasteful.
The 90's generation thinks of SUVs as "normal" cars. They frown on any car
(big or small) as not having enough room, unsafe, and inadeqate off-road.
But the kids I see being educated now have an entirely different set of
preconceptions. They are far more concerned with pollution and energy
shortages, and have very high expectations for style and convenience
features. I don't know if EVs will satisfy them -- but I *do* know they are
*not* satisfied with big cars, small cars, or SUVs! They are going to demand
something very different when their turn comes to vote with their new-car
dollars!
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
It's on display here: http://www.omniplex.org/
If for some reason your ever driving through Oklahoma, it's near I-35 and I-40.
These were taken with a Motorola V400 camera phone, so they aren't the best:
http://photobucket.com/albums/a168/rtz549/Sunrayce95/
--- End Message ---
--- Begin Message ---
Has anyone used any of these large capacitors to be
there 12volt auxilary "battery?"
Which model?
--- Mark Dodrill <[EMAIL PROTECTED]> wrote:
> Maxwell Technologies
> http://www.maxwell.com
>
> Epcos
> http://www.epcos.com
>
> Nesscap Co.
> http://www.nesscap.com
>
>
> On 12/21/05, mike golub <[EMAIL PROTECTED]> wrote:
> >
> > Who sells the 150F and larger capacitors?
> >
> > Thanks!
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Tired of spam? Yahoo! Mail has the best spam
> protection around
> > http://mail.yahoo.com
> >
> >
>
>
> --
> Mark
>
>
__________________________________________
Yahoo! DSL Something to write home about.
Just $16.99/mo. or less.
dsl.yahoo.com
--- End Message ---
--- Begin Message ---
Hey listers
Monster Garage followers!
The Monster Garage Challenge will happen this Friday at the Bakersfield drag
strip. In Bakersfield California.
We will be running Bella Da Red against a 426 Hemi Car, that is being buildt
this week.
So... we should get our Butt kicked pretty hard.
But... we will do the best we can...
I get another week of running around with my tail on fire...in front of TV
cameras. Hey I am getting good at this.
I will be happy with 13s. And not breaking the car. OK.... Nuff said!
13s 14s 8s and 1400 hp.. yea right. A good clean run and no fireworks ,injuries
or law suits is my goal.
So... more fun to follow.
Rich Rudman
Madman
--- End Message ---
--- Begin Message ---
At 07:57 PM 26/12/05 -0500, Lee Hart wrote:
> So there is an [apparent]
> inductor sitting in a pair of magnetic fields, one for the throttle
request,
> the other from the traction cable as feedback.
An iron core inductor with no magnets around is symmetrical. If you build an
oscillator with this inductor, it will have a 50% duty cycle.
If you bias it with a magnet, the core will saturate easier in one direction.
Its inductance for positive current will be different than for negative
current. If you build an oscillator with this coil, its duty cycle will be
assymetrical.
Thus, their circuit could be looking at the duty cycle of an LC oscillator's
waveform to determine the position of the magnets, and thus the throttle
position.
Hmm, OK, so when current in the traction loop is high, it'll pull the
waveform back towards unity (since the traction cable is slap on top of the
coil). Then as the RPMs pick up, the current in the traction loop will
fall, allowing more asymmetry from the throttle position magnet as the
traction current falls, so current limiting right on the throttle sensor!
Wouldn't really expect anything else from an SCR controller designer -
minimise the part count, maximise reliability.
> Now one of the things that Lansing Bagnall did is to build up the control
> circuit of their SCR controllers with a bunch of plug-in modules --
> multivibrator, pulse selector, pulse shaper, trigger circuit, con. hold
> circuit. Each in their own module, a little bigger than a matchbox,
> plugging into a set of sockets.
Cute; like home-made integrated circuits. :-) I wonder if they did this for
easier serviceability, or to allow rapid customization for different customer
requirements.
Hah! more like making sure all spares had to come from them.
But they are all fully potted, so there is the point of a failed section of
a circuit can be replaced, instead of an entire potted PCB.
Regards
James
--- End Message ---
--- Begin Message ---
Hey Rich,
Don't forget the EV Scare. It has happen to me more than once or twice
at the line. The pressure is so great on the ICE driver not to lose to
something that runs on batteries that they redlight. When you add in
the "legendary" power of the HEMI, the TV cameras, and the driver's
personal ties to the ICE car, the race may be over before it starts. If
not, I have this feeling we will still have something for them. I will
be happy with 13.50 and I really don't care if the whole thing blows as
long as it's past 1321 ft. What color does Lithium burn?
SDL
-----Original Message-----
From: Rich Rudman <[EMAIL PROTECTED]>
To: [email protected]
Sent: Mon, 26 Dec 2005 22:21:29 -0800
Subject: MG Challenge.
Hey listers
Monster Garage followers!
The Monster Garage Challenge will happen this Friday at the Bakersfield
drag
strip. In Bakersfield California.
We will be running Bella Da Red against a 426 Hemi Car, that is being
buildt
this week.
So... we should get our Butt kicked pretty hard.
But... we will do the best we can...
I get another week of running around with my tail on fire...in front of
TV
cameras. Hey I am getting good at this.
I will be happy with 13s. And not breaking the car. OK.... Nuff said!
13s 14s 8s and 1400 hp.. yea right. A good clean run and no fireworks
,injuries
or law suits is my goal.
So... more fun to follow.
Rich Rudman
Madman
--- End Message ---
--- Begin Message ---
hey rich
what time???I am going to be in big bear and it is not
too far from bakersfield. and what the 'ell is Bella
Da Red...does it have any chance of even getting close
to the hemi??? Is it open to spectators? Want some
moral support???
keith
--- Rich Rudman <[EMAIL PROTECTED]> wrote:
> Hey listers
>
> Monster Garage followers!
>
> The Monster Garage Challenge will happen this Friday
> at the Bakersfield drag strip. In Bakersfield
> California.
>
> We will be running Bella Da Red against a 426 Hemi
> Car, that is being buildt this week.
>
> So... we should get our Butt kicked pretty hard.
>
> But... we will do the best we can...
>
> I get another week of running around with my tail on
> fire...in front of TV cameras. Hey I am getting
> good at this.
>
> I will be happy with 13s. And not breaking the car.
> OK.... Nuff said!
>
> 13s 14s 8s and 1400 hp.. yea right. A good clean run
> and no fireworks ,injuries or law suits is my goal.
>
> So... more fun to follow.
>
> Rich Rudman
> Madman
>
>
__________________________________
Yahoo! for Good - Make a difference this year.
http://brand.yahoo.com/cybergivingweek2005/
--- End Message ---
--- Begin Message ---
My question though is this:
My plan is to connect my electric motor to my rear end pumpkin directly via
a gear and chain. The reason I am asking for max RPM is that I will be
running a gas motor at highway speeds. Right now it looks like my
driveshaft speeds will not exceed 5000 RPM but if I gear down the electric
motor for good city driving the highway speeds will drive the electric motor
to about 6 or 7,000 rpm. The electric motor will NOT be energized during
this time but will be freewheeling. I just want to make sure the electric
motor is not going to be damaged when in gas mode. I have thought about
using a comet torque converter. They have a model that can take 200 HP.
The only thought I have is can I adapt the driven pulley to have a
driveshaft connection on each end so I can bolt it to the pumpkin and have a
PTO connection for the driveshaft of the gas engine.
-----Original Message-----
From: James Massey [mailto:[EMAIL PROTECTED]
Sent: Friday, December 16, 2005 5:50 PM
To: [email protected]
Subject: RPM, brushes and commutators, was: RE: CVT transmission for EV
At 06:23 AM 16/12/05 -0500, Jody wrote:
>What is the maximum RPM limit of the WarP 9" ???? Is the limit because the
>brushes will pull away from the commutator or the bearings won't take it?
Hi Jody
Your question reveals a misconception or a misunderstanding you seem to
have with brush/commutator assembly. If the commutator is not perfectly
round, or not 'true' to the rotation of the rotor, the brushes will bounce
at speed, arc and die. This will happen very quickly, so a great deal of
effort is placed in making sure that the brushes do not bounce, i.e. the
commutator is truly round.
Once the brushes are running on a round commutator, sheer speed cannot harm
them, there is no centrifical or other forces being put onto the to the
brushes from the comutator. There comes a point where with enough volts and
enough amps, the gaps between the commutator bars cannot clear the energy
and then an arc occurrs that goes brush-to-brush over the surface of the
commutator.
The commutator itself is the weakest link. It IS affected by centrifical
force, so that high RPMs are trying very hard to throw the commutator (and
the windings, but they are held in a different, stronger, manner) away from
the rotor.
The voltage and power requirements of the commutator prevents the
commutator from being made in really small diameters, so we will always
have this limitation, one way or another.
The limits to a commutators' RPMs are due to the material that it is
constructed from. In ye olde days of double-breasted sandshoes and leather
flywheels (as my electronics instructor of 20-odd years ago used to put it)
commutators were constructed mechanically. The commutator bars were
insulated with mica sheet and held in place by steel rings each end. The
limit on RPMs with this method is when the copper of the bar 'bows out'
enough to allow the mica to come loose or cause brush problems, or the
copper bar breaks.
In more recent decades, commutator bars are held in by a hard plastic of
some description - generally 'bakelite' or a similar product. If this gets
too hot, or exceeds its' mechanical strength, a single bar is loosened
first, and nothing is there to stop it flying out, so EVERYTHING gets
smashed, brush gear, all the other comm bars (which as soon as the first
bar is loose quickly follow).
Madman pointed out on-list a couple of years ago that racer-EVers had
placed kevlar banding onto their commutators to prevent this wholesale
destruction in the event of comm failiure. I don't know how common this
method is, or how effective it is, so if anyone (Rich?) knows, please post
it. Until Jim Husted recognised my commutator for a steel-ring type, I had
planned on Kevlar banding my commutator, but there would be no benefit.
Hope this helps
James
--- End Message ---
--- Begin Message ---
once again lee brings insight and informed opinion to
the list
thanks
now if we can only come up with an idea that will
capture the imagination of that upcoming generation
Maybe an economical safe composite electric three
wheeler
ok jerry???
>
> You know, people don't live forever. New generations
> keep coming in to replace
> the old ones. When they do, they have entirely new
> perceptions.
>
> My parents grew up in the 1950's with Big American
> Iron. To this day,
> full-size American cars are "normal" to them. It's
> what they drive, and what
> they like. They think little cars are dangerous, and
> big SUVs are
> uncomfortable trucks.
>
> I grew up in the 70's, when small cars became
> commonplace. Small, nimble,
> efficient, lower-polluting cars are "normal" to me.
> The old land yachts and
> newer SUVs strike me as pointlessly huge, awkward,
> and wasteful.
>
> The 90's generation thinks of SUVs as "normal" cars.
> They frown on any car
> (big or small) as not having enough room, unsafe,
> and inadeqate off-road.
>
> But the kids I see being educated now have an
> entirely different set of
> preconceptions. They are far more concerned with
> pollution and energy
> shortages, and have very high expectations for style
> and convenience
> features. I don't know if EVs will satisfy them --
> but I *do* know they are
> *not* satisfied with big cars, small cars, or SUVs!
> They are going to demand
> something very different when their turn comes to
> vote with their new-car
> dollars!
> --
> Lee A. Hart 814 8th Ave N Sartell MN 56377
> [EMAIL PROTECTED]
>
>
__________________________________
Yahoo! for Good - Make a difference this year.
http://brand.yahoo.com/cybergivingweek2005/
--- End Message ---
--- Begin Message ---
--- Bob Bath <[EMAIL PROTECTED]> wrote:
> I'd still say the 92-95 Honda Civics are a far
> superior candidate to either of the rigs mentioned.
> It simply has a huge spare tire well that shrieks,
> "I'm MADE for flooded USBatts!" I also consider it
> a
> safer roll cage in the event of accident, and the
> fact
> is, there were, and still are, 20-25,000 running off
> the line PER MONTH.
Are you implying that this vehicle is still in
production and for sale somewhere in the world??????
You will have spare parts,
> aftermarket parts, etc. for a _very_ long time.
> The biggest hassle (as is with other cars, too),
> is
> yanking the heater core, and swapping the power rack
> for a manual one.
> Newbies, if you're interested, inquire about the
> DVD/VHS.
> I'd start making a kit available, (contactor mount,
> controller mount, throttle mount, motor/vac. pump
> mount, heater relay mount), but I'm just not
> convinced
> there is a market at the ready, yet. And I use DCP
> DCDC converter and controller, which don't quite
> exist
> anymore.
> peace,
>
> --- Don Cameron <[EMAIL PROTECTED]> wrote:
>
> > Nothing wrong with blazing a new trail. My New
> > Beetle EV is only one of
> > three in the world.
> >
> > What is nice about the Metro is that there is a
> lot
> > more expertise available
> > if you want parts or advice. Before I did the New
> > Beetle conversion, I
> > purchased a 96 Metro, and it has enough room to
> > accommodate a 9" ADC motor.
> >
> >
> > good luck.
> > Don
> >
> >
> >
> >
> > Victoria, BC, Canada
> >
> > See the New Beetle EV Conversion Web Site at
> > www.cameronsoftware.com/ev/
> >
> > -----Original Message-----
> > From: [EMAIL PROTECTED]
> > [mailto:[EMAIL PROTECTED] On
> > Behalf Of [EMAIL PROTECTED]
> > Sent: December 26, 2005 1:36 PM
> > To: [email protected]
> > Subject: Festiva or Metro
> >
> > If you were converting a "small car" today, would
> > you rather used a late
> > model Ford Festiva or Geo Metro. I looked at both
> > cars earlier today and I
> > believe the Festiva to be a superior conversion
> > candidate. But, I am
> > interested in what others have to say, and why
> other
> > people aren't choosing
> > the Festiva.
> >
> > In my opinion, advantages of the Festiva:
> > There is at least 2.75" more length to fit a motor
> > which opens up a lot more
> > options than the 8" ADC.
> > - You could even easily fit a Warp 9" for
> > some serious performance.
> > Battery mounting appears to be easier, especially
> if
> > you take out the rear
> > seat, which is very easy Currently, you may be
> able
> > to get a donor car
> > pretty inexpensively
> >
> >
> > In my opinion, disadvantages of the Festiva:
> > No off the shelf kit, as far as I know
> > Few examples to work from
> > Parts availability - 5 years from now - is
> > questionable The cars are
> > generally older and more difficult to find in low
> > mileage Stock brakes seem
> > a little small - from what I could tell from the
> > disassembled car
> >
> > I would like to know what others think, and why
> they
> > decided to go with the
> > Metro rather than the Festiva. I think the
> Festiva
> > with the 9" motor and 14
> > x
> > 12 V AGM batteries and a 1k Zilla controller
> locked
> > in 2nd gear would make a
> > great car. I think better than a comparable Metro
> > which would be limited to
> > a 8" ADC and 12 x 12 V batteries (I've heard space
> > issues). Anyone need to
> > correct me?
> >
> >
>
>
> '92 Honda Civic sedan, 144V (video or DVD
> available)!
> www.budget.net/~bbath/CivicWithACord.html
> ____
> __/__|__\ __
> =D-------/ - - \
> 'O'-----'O'-'
> Would you still drive your car if the tailpipe came
> out of the steering wheel? Are you saving any gas
> for your kids?
>
>
>
> __________________________________________
> Yahoo! DSL Something to write home about.
> Just $16.99/mo. or less.
> dsl.yahoo.com
>
>
__________________________________
Yahoo! for Good - Make a difference this year.
http://brand.yahoo.com/cybergivingweek2005/
--- End Message ---
--- Begin Message ---
Why not get a mutli pulley from www.mcmaster.com I think they are called
step pulleys. You can get them in any shaft diameter from 1/2 to 5/8 for
pretty cheap. Then you can try out different diameters to suit your
application.
-----Original Message-----
From: Roger Stockton [mailto:[EMAIL PROTECTED]
Sent: Thursday, December 22, 2005 5:09 PM
To: [email protected]
Subject: RE: pulleys question
Seth Rothenberg [mailto:[EMAIL PROTECTED] wrote:
> The motor pulley is 2.5"
> The thrower pulley is 5" (is that 2:1? or am I backwards? :-)
2:1. The motor rotates twice per revolution of the thrower.
> I got the following: 1.5", 2", and 6".
>
> My thought was to mount (in thin air :-) the 1.5" and the 6"
> and magically bind them together, so the original 2.5 drives
> a 6", which is concentric with 1.5" which drives the 5".
> (is that 6:1.5? = 4:1?) Is that too low?
6:2.5 = 2.4:1
5:1.5 = 3.33:1
2.4 * 3.33 = 8, so the overall speed reduction with this setup is 8:1
(the motor will rotate 8 times per revolution of the thrower).
Hope this helps,
Roger.
--- End Message ---
--- Begin Message ---
People refrain from making a kit around a car like
this, b/c it gets updated every 4 years. My point was
to say, "stick with the 92-95; don't worry that later
models may have different dimensions and not be so
easy to get batteries into. No, they (92-95) aren't
still in production, but 12 mos. x 20K cars per mo., x
4 model years =960,000 vehicles, they way I see it.
--- keith vansickle <[EMAIL PROTECTED]>
wrote:
>
>
> --- Bob Bath <[EMAIL PROTECTED]> wrote:
>
> > I'd still say the 92-95 Honda Civics are a far
> > superior candidate to either of the rigs
> mentioned.
> > It simply has a huge spare tire well that shrieks,
> > "I'm MADE for flooded USBatts!" I also consider
> it
> > a
> > safer roll cage in the event of accident, and the
> > fact
> > is, there were, and still are, 20-25,000 running
> off
> > the line PER MONTH.
>
>
>
>
> Are you implying that this vehicle is still in
> production and for sale somewhere in the world??????
>
>
>
>
>
>
>
> You will have spare parts,
> > aftermarket parts, etc. for a _very_ long time.
> > The biggest hassle (as is with other cars,
> too),
> > is
> > yanking the heater core, and swapping the power
> rack
> > for a manual one.
> > Newbies, if you're interested, inquire about the
> > DVD/VHS.
> > I'd start making a kit available, (contactor
> mount,
> > controller mount, throttle mount, motor/vac. pump
> > mount, heater relay mount), but I'm just not
> > convinced
> > there is a market at the ready, yet. And I use
> DCP
> > DCDC converter and controller, which don't quite
> > exist
> > anymore.
> > peace,
> >
> > --- Don Cameron <[EMAIL PROTECTED]> wrote:
> >
> > > Nothing wrong with blazing a new trail. My New
> > > Beetle EV is only one of
> > > three in the world.
> > >
> > > What is nice about the Metro is that there is a
> > lot
> > > more expertise available
> > > if you want parts or advice. Before I did the
> New
> > > Beetle conversion, I
> > > purchased a 96 Metro, and it has enough room to
> > > accommodate a 9" ADC motor.
> > >
> > >
> > > good luck.
> > > Don
> > >
> > >
> > >
> > >
> > > Victoria, BC, Canada
> > >
> > > See the New Beetle EV Conversion Web Site at
> > > www.cameronsoftware.com/ev/
> > >
> > > -----Original Message-----
> > > From: [EMAIL PROTECTED]
> > > [mailto:[EMAIL PROTECTED] On
> > > Behalf Of [EMAIL PROTECTED]
> > > Sent: December 26, 2005 1:36 PM
> > > To: [email protected]
> > > Subject: Festiva or Metro
> > >
> > > If you were converting a "small car" today,
> would
> > > you rather used a late
> > > model Ford Festiva or Geo Metro. I looked at
> both
> > > cars earlier today and I
> > > believe the Festiva to be a superior conversion
> > > candidate. But, I am
> > > interested in what others have to say, and why
> > other
> > > people aren't choosing
> > > the Festiva.
> > >
> > > In my opinion, advantages of the Festiva:
> > > There is at least 2.75" more length to fit a
> motor
> > > which opens up a lot more
> > > options than the 8" ADC.
> > > - You could even easily fit a Warp 9"
> for
> > > some serious performance.
> > > Battery mounting appears to be easier,
> especially
> > if
> > > you take out the rear
> > > seat, which is very easy Currently, you may be
> > able
> > > to get a donor car
> > > pretty inexpensively
> > >
> > >
> > > In my opinion, disadvantages of the Festiva:
> > > No off the shelf kit, as far as I know
> > > Few examples to work from
> > > Parts availability - 5 years from now - is
> > > questionable The cars are
> > > generally older and more difficult to find in
> low
> > > mileage Stock brakes seem
> > > a little small - from what I could tell from the
> > > disassembled car
> > >
> > > I would like to know what others think, and why
> > they
> > > decided to go with the
> > > Metro rather than the Festiva. I think the
> > Festiva
> > > with the 9" motor and 14
> > > x
> > > 12 V AGM batteries and a 1k Zilla controller
> > locked
> > > in 2nd gear would make a
> > > great car. I think better than a comparable
> Metro
> > > which would be limited to
> > > a 8" ADC and 12 x 12 V batteries (I've heard
> space
> > > issues). Anyone need to
> > > correct me?
> > >
> > >
> >
> >
> > '92 Honda Civic sedan, 144V (video or DVD
> > available)!
> > www.budget.net/~bbath/CivicWithACord.html
> > ____
> > __/__|__\ __
> > =D-------/ - - \
> > 'O'-----'O'-'
> > Would you still drive your car if the tailpipe
> came
> > out of the steering wheel? Are you saving any gas
> > for your kids?
> >
> >
> >
> > __________________________________________
> > Yahoo! DSL Something to write home about.
> > Just $16.99/mo. or less.
> > dsl.yahoo.com
> >
> >
>
>
>
>
>
> __________________________________
> Yahoo! for Good - Make a difference this year.
> http://brand.yahoo.com/cybergivingweek2005/
>
>
'92 Honda Civic sedan, 144V (video or DVD available)!
www.budget.net/~bbath/CivicWithACord.html
____
__/__|__\ __
=D-------/ - - \
'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering wheel?
Are you saving any gas for your kids?
__________________________________________
Yahoo! DSL Something to write home about.
Just $16.99/mo. or less.
dsl.yahoo.com
--- End Message ---
--- Begin Message ---
There is a book that has a controller you can build published this year. It
is called Mechatronics for the Evil Genius. The only difference you will
have to do is use the high power mosfets mentioned in other posts. The ones
I read about could handle 250 amps each if I remember right. They were kind
of pricey though.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Sent: Friday, December 23, 2005 11:47 AM
To: [email protected]
Subject: I want to build a PWM DC motor controller
I have some time to work on developing a basic PWM DC motor controller. I
am
not looking for all the frills, just something basic with the critical
safety
features. The target performance is 144 V / 600 A.
It turns out that this may be more difficult than I originally thought. I
was under the impression that there are off the shelf motor control chips
and
all I basically had to do was buy the parts and spend "a lot" of time
assembling
it and testing it. So far, I haven't found that to be the case.
I read Bob Brant's book about 8 years ago, but I figure that all of those
references are now obsolete, and that much better technology is now
available.
Also, as I remember, the information was incomplete, and I couldn't actually
build one with the information that was provided without doing a lot of
additional research and expensive trial and error.
It was recently suggested that I use the Freescle MC68HC908QY4 IC. I
checked
the website, and in fact, Freescale recommends that series of chips for this
application. That still leaves a lot of holes in the plan. So, before I
re-invent the wheel, is there anyone on the list who has successfully built
such a
controller and can provide some details of the component layout and
processer
algorithm used.
As far as the I/O goes, I was going to use:
1 analog input - 0 - 5 k standard pot
1 digital input - overcurrent protection
As far as the algorithm goes, I was going to use:
First, a fixed pulse width with a variable time delay between pluses
Then, after a specified crossover, a variable pulse width and a variable
time
delay between the pulses.
I would have a logic lockout to prevent the motor from starting if the
throttle is over 25%
That is pretty much it, but I may also need to consider some way to detect
1. Welded contactor
2. FET failure - full open
Can any of you provide some direction / guidance on this project?
Thanks,
Steve
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: Dewey, Jody R ATC (CVN75 IM3)<mailto:[EMAIL PROTECTED]>
To: '[email protected]'<mailto:'[email protected]'>
Sent: Tuesday, December 27, 2005 5:42 AM
Subject: RE: RPM, brushes and commutators, was: RE: CVT transmission for EV
My question though is this:
My plan is to connect my electric motor to my rear end pumpkin directly via
a gear and chain. The reason I am asking for max RPM is that I will be
running a gas motor at highway speeds. Right now it looks like my
driveshaft speeds will not exceed 5000 RPM but if I gear down the electric
motor for good city driving the highway speeds will drive the electric motor
to about 6 or 7,000 rpm. The electric motor will NOT be energized during
this time but will be freewheeling. I just want to make sure the electric
motor is not going to be damaged when in gas mode. I have thought about
using a comet torque converter. They have a model that can take 200 HP.
The only thought I have is can I adapt the driven pulley to have a
driveshaft connection on each end so I can bolt it to the pumpkin and have a
PTO connection for the driveshaft of the gas engine.
Your electric motor rpm will be lower then the engine rpm.
Lets say the engine is at 4000 rpm and drive line is at 4000 rpm, if the
differential gear is 4 to 1 ratio, then the axle rpm is 1000 rpm.
If you connect a 3 inch sprocket on the drive line and a 9 inch sprocket on
the motor, this is a 3 to 1 ratio. For every 3 rpm that the driveline rotates
the motor will rotate 1 rpm.
The maximum rpm of the engine at 5000 rpm would be 5000/3:1 = 1666 rpm.
Therefore the overall gear ratio to the axles is 4:1 x 3:1 when motor is
running would be 12:1 ratio.
The formula for speed of vehicle:
RPM x Wheel Circumference
MPH = ---------------------------------
Overall Axle Ratio x 1056
RPM is the electric motor RPM
Wheel Circumference is the rolling circumference in inches by marking the
tire and rotate it one revolution on a flat
grade.
Overall Axle Ratio is the transmission gear ratio or any other gear
reduction
ratio times the differential gear.
1056 is a constant to convert the axle rpm which is in inches per minute to
feet per minute and than to miles per hour or:
5280 ft per mile x 12 inches per ft.
1056 = ---------------------------------------
60 minutes per hour
Therefore the mph at 4000 electric motor rpm would be with a wheel
circumference of 85 inches using a 4:1 axle ratio and a sprocket ratio of 3:1
would be:
1000 RPM x 85 inches
MPH = ----------------------------- = 6.7 Mph
12:1 ratio x 1056
Therefore for every 1000 RPM, you have 6.7 Mph
At 7000 electric motor RPM than you will have 7 x 6.7 = 46.9 Mph.
In my EV, my 2nd gear ratio is about 13.5:1 which is about 35 Mph. I
therefore can shift from 19.5:1 1st gear to a 5.57:1 gear which gives me about
92 MPH at 6000 Rpm with a 90 inch wheel circumference.
I normally have to stay in 2nd gear for any speed under 35 mph which keeps
the RPM up and motor amperes down to 150 amps and battery amps to 50.
If your EV weight is at 3000 lbs than a 3:1 sprocket gear ratio for a overall
ratio of 9:1 will work for about 100 motor amperes. For every 1000 lbs of
weight its about a 3:1 ratio increase, so a 4000 lb EV should be at 12:1 and
5000 lb at 15:1 and etc.
Roland
-----Original Message-----
From: James Massey [mailto:[EMAIL PROTECTED]
Sent: Friday, December 16, 2005 5:50 PM
To: [email protected]<mailto:[email protected]>
Subject: RPM, brushes and commutators, was: RE: CVT transmission for EV
At 06:23 AM 16/12/05 -0500, Jody wrote:
>What is the maximum RPM limit of the WarP 9" ???? Is the limit because the
>brushes will pull away from the commutator or the bearings won't take it?
Hi Jody
Your question reveals a misconception or a misunderstanding you seem to
have with brush/commutator assembly. If the commutator is not perfectly
round, or not 'true' to the rotation of the rotor, the brushes will bounce
at speed, arc and die. This will happen very quickly, so a great deal of
effort is placed in making sure that the brushes do not bounce, i.e. the
commutator is truly round.
Once the brushes are running on a round commutator, sheer speed cannot harm
them, there is no centrifical or other forces being put onto the to the
brushes from the comutator. There comes a point where with enough volts and
enough amps, the gaps between the commutator bars cannot clear the energy
and then an arc occurrs that goes brush-to-brush over the surface of the
commutator.
The commutator itself is the weakest link. It IS affected by centrifical
force, so that high RPMs are trying very hard to throw the commutator (and
the windings, but they are held in a different, stronger, manner) away from
the rotor.
The voltage and power requirements of the commutator prevents the
commutator from being made in really small diameters, so we will always
have this limitation, one way or another.
The limits to a commutators' RPMs are due to the material that it is
constructed from. In ye olde days of double-breasted sandshoes and leather
flywheels (as my electronics instructor of 20-odd years ago used to put it)
commutators were constructed mechanically. The commutator bars were
insulated with mica sheet and held in place by steel rings each end. The
limit on RPMs with this method is when the copper of the bar 'bows out'
enough to allow the mica to come loose or cause brush problems, or the
copper bar breaks.
In more recent decades, commutator bars are held in by a hard plastic of
some description - generally 'bakelite' or a similar product. If this gets
too hot, or exceeds its' mechanical strength, a single bar is loosened
first, and nothing is there to stop it flying out, so EVERYTHING gets
smashed, brush gear, all the other comm bars (which as soon as the first
bar is loose quickly follow).
Madman pointed out on-list a couple of years ago that racer-EVers had
placed kevlar banding onto their commutators to prevent this wholesale
destruction in the event of comm failiure. I don't know how common this
method is, or how effective it is, so if anyone (Rich?) knows, please post
it. Until Jim Husted recognised my commutator for a steel-ring type, I had
planned on Kevlar banding my commutator, but there would be no benefit.
Hope this helps
James
--- End Message ---
--- Begin Message ---
Hi Steve etc.
Here's the program I used in my cheese wedge, Electro-Metro and E-jeep:
Might be better to view in "fixed font" since I imported from Notepad
*************************************************************************
* *
* Electric Vehicle Computer - motor speed control *
* Name: metrol.asm date 6/24/97 600A *
* Copyright 1997 Mark E. Hanson All Rights Reserved *
* *
*************************************************************************
*************************************************************************
* *
* Set up Port names to be recognized in program *
* *
*************************************************************************
Porta equ 0 Porta is register 0
Portb equ 1 Portb is register 1
Portc equ 2 Portc is register 2
Portd equ 3 Portd is register 3
ddra equ 4 data direction registers
ddrb equ 5
ddrc equ 6
ddrd equ 7
*************************************************************************
* *
* Port line pin definitions *
* *
*************************************************************************
* Flags
* INS
pot equ $20 motor temp a-d
* OUTS
led equ 7 Portb led for interrupt current limit
pwm equ 6 Portb pwm output
* Mode button is interrupt line
cop equ $1ff0 COP register reset location
*************************************************************************
* *
* RAM register locations *
* *
*************************************************************************
atod equ $21 a/d
acr equ $1e a/d control register
arr equ $1d a/d result register
* RAM:
del1 equ 129 firmware timer delay registers
del2 equ 130
del3 equ 131
ton equ 132 time on pwm
toff equ 133 time off pwm
*************************************************************************
* *
* Set up vector registers for reset/interrupts *
* *
*************************************************************************
* Timer vector set
org $0900
byte $01
org $1f00 0900 is P9
byte $03 turn on cop and low level int trigger
org $1ff8
fdb $0850 timer interrupt vector
fdb $0850 external interrupt vector
fdb $0850 SWI same as timer
fdb $0100 reset vector
* External Interrupt Routine
org $0850
bclr pwm,Portb
bset led,Portb
rti
* Timer Interrupt Routine
*************************************************************************
* *
* Main Program *
* *
*************************************************************************
* Initialize port bits
org $100
clr Porta clear port data registers
clr Portb
clr Portc
clr Portd
bset led,ddrb set ddrb led to output
bset pwm,ddrb
bset led,Portb blink led
lda #$20
sta acr turn on a-d converter
ldx #10 1/2 sec delay
cli activate interrupt
* Program
Wait stx del3
clrx
stx cop
ldx #249 223 for 3.8 mHz or 249 for 4 mHz
stx del1
flip3 ldx #65
stx del2
flip2 ldx del1
flip1 dex
bne flip1
stx cop
ldx del2
dex
stx del2
bne flip2
over ldx del3
dex
stx del3
bne flip3
Peddle bclr pwm,Portb
ad bclr led,Portb
lda #pot read pot
sta acr
anal brclr 7,acr,anal
lda arr
stx cop
cmp #15 if pot below lim then off
blo Peddle
cmp #242 if pot above lim then wire broken = off
bhi Peddle
sub #7
sta ton set ton pwm 4 kHz 2usec per count
lda #169
sub ton
sta toff set toff pwm
back deca
nop
bne back
bset pwm,Portb
lda ton
back2 deca
nop
bne back2
lda arr
cmp #166 check for full on
bhi ad
bra Peddle
* That's all Folks!
end
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, December 23, 2005 11:46 AM
Subject: I want to build a PWM DC motor controller
> I have some time to work on developing a basic PWM DC motor controller. I
am
> not looking for all the frills, just something basic with the critical
safety
> features. The target performance is 144 V / 600 A.
>
> It turns out that this may be more difficult than I originally thought. I
> was under the impression that there are off the shelf motor control chips
and
> all I basically had to do was buy the parts and spend "a lot" of time
assembling
> it and testing it. So far, I haven't found that to be the case.
>
> I read Bob Brant's book about 8 years ago, but I figure that all of those
> references are now obsolete, and that much better technology is now
available.
> Also, as I remember, the information was incomplete, and I couldn't
actually
> build one with the information that was provided without doing a lot of
> additional research and expensive trial and error.
>
> It was recently suggested that I use the Freescle MC68HC908QY4 IC. I
checked
> the website, and in fact, Freescale recommends that series of chips for
this
> application. That still leaves a lot of holes in the plan. So, before I
> re-invent the wheel, is there anyone on the list who has successfully
built such a
> controller and can provide some details of the component layout and
processer
> algorithm used.
>
> As far as the I/O goes, I was going to use:
> 1 analog input - 0 - 5 k standard pot
> 1 digital input - overcurrent protection
>
> As far as the algorithm goes, I was going to use:
> First, a fixed pulse width with a variable time delay between pluses
> Then, after a specified crossover, a variable pulse width and a variable
time
> delay between the pulses.
> I would have a logic lockout to prevent the motor from starting if the
> throttle is over 25%
>
> That is pretty much it, but I may also need to consider some way to detect
> 1. Welded contactor
> 2. FET failure - full open
>
> Can any of you provide some direction / guidance on this project?
>
> Thanks,
>
> Steve
>
--- End Message ---
