EV Digest 6813
Topics covered in this issue include:
1) Re: Award winner!!
by Frank John <[EMAIL PROTECTED]>
2) July Hot Rod magazine
by Frank John <[EMAIL PROTECTED]>
3) RE: Triangle wave generator
by "Dale Ulan" <[EMAIL PROTECTED]>
4) Re: Award winner!!
by John Wayland <[EMAIL PROTECTED]>
5) Re: Triangle wave generator
by tt2tjw <[EMAIL PROTECTED]>
6) RE: Triangle wave generator
by Steve Peterson <[EMAIL PROTECTED]>
7) Re: Burnt out PM Motor?
by Jeff Major <[EMAIL PROTECTED]>
8) RE: Go kart drag race safety vs mini-bike
by Tim Humphrey <[EMAIL PROTECTED]>
9) Re: How regen works
by "Peter VanDerWal" <[EMAIL PROTECTED]>
10) Re: Reality check, Re: Permanent magnet motor question
by "Peter VanDerWal" <[EMAIL PROTECTED]>
11) Re: Burnt out PM Motor?
by Rod Hower <[EMAIL PROTECTED]>
12) Re: Fast and Eff!!! Re: White Zombie gets to 'test' drive Lithium!
by John Wayland <[EMAIL PROTECTED]>
13) Re: Reality check, Re: Permanent magnet motor question
by "Peter VanDerWal" <[EMAIL PROTECTED]>
14) Re: How regen works
by Lee Hart <[EMAIL PROTECTED]>
15) Before I put it on Ebay- PM Motor
by Mark Ward <[EMAIL PROTECTED]>
16) RE: Fast and Eff!!! Re: White Zombie gets to =?UTF-8?B?J3Rlc3QnCWRyaXZl?=
=?UTF-8?B?IExpdGhpdW0h?=
by Tim Humphrey <[EMAIL PROTECTED]>
17) Re: Raptor 600 problem
by "Andrew A." <[EMAIL PROTECTED]>
18) Re: Ni-Cad Final Taper
by Rod Hower <[EMAIL PROTECTED]>
19) Re: Fast and Eff!!! Re: White Zombie gets to 'test' drive Lithium!
by ROBERT RICE <[EMAIL PROTECTED]>
20) Re: PIR June 29-30 EV drag racing?
by "Marty Hewes" <[EMAIL PROTECTED]>
--- Begin Message ---
Way to go John! It's always nice to get validation for fine work.
----- Original Message ----
From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
To: [email protected]
Sent: Thursday, May 24, 2007 10:44:41 PM
Subject: Award winner!!
Hi all,
The Skunk is now officially an award winning conversion. I was in a parade
last Saturday and was awarded 1st place in the motorcycle division. I just
received the plaque today so its official. Just a small town parade, but
lots of viewers and many comments and discussions afterwards with the
spectators. There was a car show in conjunction with the parade and I was
parked with them afterwards where I got the comments.
Also I'm almost up to 500 mi on the bike as an electric.
respectfully,
John
The Skunk, 58 Harley servicar conversion.
http://www.austinev.org/evalbum/751
____________________________________________________________________________________Got
a little couch potato?
Check out fun summer activities for kids.
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--- End Message ---
--- Begin Message ---
Attn: hi-performance guys:
I don't know how many of you read Hot Rod (I'm not sure why I still do
sometimes...) but editor David Freiburger's "Starting Line" column is
interesting. He laments about how folks don't drive their hot rods like they
used to and that high gas prices make it even harder and that he doesn't really
need 500 hp to sit in traffic for 45 minutes for his 8 mile commute.
So he's proposing a "commuter rod" type of car - something that's not too
fancy, preferably older, offers reasonable performance and good economy but is
used every day; he wants to hear from readers about anyone doing this now. I
think that he needs to see your cars. This is a great chance to get some more
EV publicity plus show him that you don't have to sacrifice performance while
having fun. All while saving gas and money. Please consider writing him about
your cars and sending pics - [EMAIL PROTECTED]
____________________________________________________________________________________Need
a vacation? Get great deals
to amazing places on Yahoo! Travel.
http://travel.yahoo.com/
--- End Message ---
--- Begin Message ---
1. your first attempt did not follow the application notes and resulted
in blown parts then a subsequent attempt followed the application notes
and was successful?
I've done that with lots of chips and parts - not just EV motor
controls. I've been doing ICE controller design for over 10
years now, and if you miss something in the app notes, it can blow
up. When I bought IGBT's for my motor controllers, after looking
at the price tag, I thought that it would be wise to follow the
application notes carefully. Plus, Powerex has great app notes.
I've done some lower-power VFD work, my latest project was
rebuilding a 30kW BLDC controller because the original MOSFET's
had gone obsolete. When subbing in a totally new device in
the output stage of a controller, you need to re-wire everything
then re-tweak all of the switching times again.
The last EV design that I worked on with lots of blow-ups
was a battery charger. That was a small charger (only 20 amps
at 250 volts). That was before I knew anything - about 12 or
15 years ago. Eventually I took it to a guy that had a really
nice HP 'scope and figured out why it kept blowing up. The
10 MHz scope didn't show the spikeys enough. It was, by the
way, a power-factor corrected charger with a burp 'uncharger'
included to help control water loss on NiCd charging. That
would briefly stop charging and run a discharge for a brief
amount of time before charging again. It did work but I don't
know how the battery life would be with that logic. Water loss
was a lot lower, especially towards the end of the charge
cycle.
This may be a stupid question - I am a proto novice..... What do you
mean by "tame the parasitics"? Do you mean that the switching of the
IGBT causes noise in the control signal?
It causes noise in the control signal, yes. But those little spikey
things you see during the switching can be much higher in voltage
than the 'scope shows. So the parts may blow up just from simple
overvoltage. Remember that even a 100 MHz 'scope may not show a
ten nanosecond, 800 volt spike that will kill a 600 V IGBT. You
may see it as a 100 volt overshoot on a 400 volt bus. But it's
really 800 volts but just shorter in duration than the 'scope
shows. You gotta fix it. It's just easier to deal with that when
you run the circuit on 100 volts and the part isn't blowing up,
than when you crank it up to 400 volts and the part blows up after
a couple of seconds and you are wondering what the ***** happened
there? By the way, when an IGBT or MOSFET this size blows up,
in can be loud. Wear hearing protection!
You also have shoot-through currents - where the diode does not
turn off as fast as the MOSFET or IGBT turns on. Those are nasty
and was actually one of the causes of my battery charger blow-ups.
You have to know about them, and either be able to measure them
or tweak the switching speed of the MOSFET's or IGBT's to minimize
the stress caused by the momentary bus voltage short-circuit that
they cause.
-Dale
--- End Message ---
--- Begin Message ---
Hello to John and All,
Congrats on your EV taking the award. In addition to the pride of having
your work recognized, it's way cool that an EV was chosen over gas
competition....people are waking up.
See Ya....John Wayland
[EMAIL PROTECTED] wrote:
Hi all,
The Skunk is now officially an award winning conversion. I was in a
parade last Saturday and was awarded 1st place in the motorcycle
division....
--- End Message ---
--- Begin Message ---
Thanks for the detailed reply Dale,
Dale Ulan wrote:
When I bought IGBT's for my motor controllers, after looking
at the price tag, I thought that it would be wise to follow the
application notes carefully.
OK I think I understand... so when you did follow the application notes
to the letter everything worked?
those little spikey things you see during the switching can be much higher in voltage
than the 'scope shows. So the parts may blow up just from simple
overvoltage.
It's just easier to deal with that when
you run the circuit on 100 volts
But even though you have followed the application notes your should
still look for spikes or other problems at low voltage?
You also have shoot-through currents - where the diode does not
turn off as fast as the MOSFET or IGBT turns on. Those are nasty
and was actually one of the causes of my battery charger blow-ups.
You have to know about them, and either be able to measure them
or tweak the switching speed of the MOSFET's or IGBT's to minimize
the stress caused by the momentary bus voltage short-circuit that
they cause.
-
So youre saying that ...even if you have followed the physical aspects
of he application notes to the letter the IGBT could still blow up , or
be inefficient and overheat if your controller doesn't switch them
correctly?
--- End Message ---
--- Begin Message ---
On Fri, 2007-05-25 at 08:08 -0600, Dale Ulan wrote:
> But those little spikey
> things you see during the switching can be much higher in voltage
> than the 'scope shows. So the parts may blow up just from simple
> overvoltage. Remember that even a 100 MHz 'scope may not show a
> ten nanosecond, 800 volt spike that will kill a 600 V IGBT. You
> may see it as a 100 volt overshoot on a 400 volt bus. But it's
> really 800 volts but just shorter in duration than the 'scope
> shows.
So just out of curiosity, how does one detect the ten nano, 800 volt
spikes? Faster scope? Just assume they're going to be there and design
accordingly?
--Steve
--- End Message ---
--- Begin Message ---
Rod, Mark,
To test for demagnetization, you could run a generated
voltage test, couldn't you? Drive the motor at a set
speed and measure terminal voltage. Then proportion
up to nameplate (or original no-load rpm) and if the
voltage is a lot less than 24, opps, demagged. Then
what? Could you remag by turning brushes 45 degrees
and pulsing with a couple hundred amps?
Sticky brush is also possible problem.
Jeff
--- Rod Hower <[EMAIL PROTECTED]> wrote:
> If the motor was REALLY hot on 24Vdc there's a good
> chance you demagnetized the PM field or at least
> weakened it to the point of having much less
> performance. If this is the case, I would think it
> still gets pretty warm at 18Vdc. Also make sure
> that
> the brushes are properly seated on the commutator
> and
> not sticking in the holder.
>
> Rod
> --- Mark Hastings <[EMAIL PROTECTED]> wrote:
>
> > I have a 4 brush 24 volt 1.5 PM motor on my 22"
> > mower.
> > I had run it initially on 24 volts but it got far
> > too
> > hot. I now run it at 18 volts and it worked for a
> > couple mows.
> > However now it just has no power at all. Any tall
> > grass and it bogs down incredibly like the
> batteries
> > are dead. I even tried putting it back to 24 volts
> > and
> > get the same results. Does this sound like I
> ruined
> > the motor in my initial runs at 24 volts? It is
> > almost
> > as if the batteries are dead. They are freshly
> > charged
> > batteries along with a brand new set of freshly
> > charged batteries I just purchased.
> > It had been cutting wonderfully but now I can
> > hardly
> > use it.
> >
> >
>
>
____________________________________________________________________________________Pinpoint
customers who are looking for what you sell.
http://searchmarketing.yahoo.com/
--- End Message ---
--- Begin Message ---
I don't really think it takes much engineering skill to go from a go-kart to a
rail. It takes some cash, patience, skill and money. But, if he could build a
well performing go-kart, then to stretch it and add an "approved roll-cage"
should be do-able. Of course the performance will suffer from the added weight,
but then again there should be more room for more batteries.
Bill;
Would a tadpole three-wheel go-kart be "safe" on a dragstrip? i.e eliminate the
skid problem
Ken;
Being a three-wheeler, would it be considered a motorcycle by NEDRA standards?
--
Stay Charged!
Hump
I-5, Blossvale NY
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Michael Haseltine
> Sent: Thursday, May 24, 2007 4:00 PM
> To: [email protected]
> Subject: Re:Go kart drag race safety vs mini-bike
>
> I understand completely, now. And can see that long narrow drag rails
> are advantageous for more reasons than traction and aerodynamics.
> It's too bad, because that cart was really hot.
>
> Michael
>
>>The safety issues of go karts on the drag strip are not obvious, but
>>quite serious.
>>
>>It is all about traction, polar moment, and wheelbase. Karts spin
>>and flip easily on the drag strip.
>>
>>The traction on the drag strip is three times what it is on the
>>street or a go kart track. When one rear tire loses traction, (hits
>>a greasy spot) the other pushes the kart into a spin. The polar
>>moment of a kart is tiny, and the sticky track gives huge force to
>>the wheel with traction, so the spin is almost instantaneous. There
>>is no time for the driver to react, lift the throttle, and steer the
>>kart straight.
>>
>> The kart is wide and short, so the rear wheel that has
>>traction has too much leverage on the CG and can easily overpower
>>the steering traction of the front wheels. Even if you steer quickly
>>enough, the rear tire with traction has enough force to make the
>>front tires skid sideways, so steering has no effect.
>>
>> On the kart track, if the kart gets sideways, it just slides
>>sideways. On the drag strip, the traction is so good that the tires
>>dig in and the kart flips instead of sliding.
>>
>> Thus, a small greasy section on the track is all it takes to
>>spin and flip the kart because it happens so fast. A car with more
>>polar moment, longer wheelbase, and narrower track might just weave
>>a bit over the same greasy spot.
>>
>> With a motorcycle, there is only one back tire. If it loses
>>traction briefly, the bike still goes straight down the track.
>>Losing traction briefly does not cause a bike to instantly spin and
>>flip, like it will a kart on the drag strip.
>>
>> It isn't at all simple, is it? That is why NEDRA originally
>>allowed karts, because we didn't know any better in the beginning.
>>
>> Bill Dube'
>>
>>
>>At 11:13 AM 5/24/2007, you wrote:
>>>All this excitement over the AGNS minibike reminded me of the
>>>gokart that was in the same league (12.102 sec. at 102.71mph) a few
>>>years back that blew my mind, and in tracking it down found that
>>>the NEDRA website says the gokart class has been dropped for safety
>>>reasons. Can it be any different than for minibikes? BTW, I'm
>>>certainly not thinking that the minibike class should also be
>>>dropped!! Rather the other way round.
>>>
>>>--
>>>Michael Haseltine
>
>
--- End Message ---
--- Begin Message ---
I've heard this, I just don't quite understand how you keep them turned on
when they are reversed.
As I understand it (and it's been a couple years since I played with
them), for an NPN Mosfet to conductm the gate has to be approx 10V more
positive than the drain (unless you are using one of those 'spensive
FETs).
If it's reversed, then won't the drain have to go to a higher voltage than
the source side? I.e. 10V higher voltage than your pack voltage?
I can see how you could do this, but it would take more than just a
programming upgrade.
> MOSFETs will conduct either direction when ON. One direction when OFF due
> to the body diode.
>
> So Whenever you want to improve efficiency by taking the body diode
> voltage
> drop out, you can just switch the gate on and let it bypass the body
> diode.
>
> Software can do this at the right time and you get synchronous behavior.
>
> -Phil
> ----- Original Message -----
> From: "Peter VanDerWal" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Thursday, May 24, 2007 5:46 PM
> Subject: RE: How regen works
>
>
>>> ..aren't very good diodes, so if a controller uses them, the maximum
>>> regen
>>> current won't be as high as the maximum motoring current.
>>>
>>> Unless you use synchronous rectification - which uses the MOSFET in
>>> reverse. You probably want to do that anyways to lower the losses.
>>
>> Can you explain this? The few synchoronous rectification designs I've
>> studied used a second MOSFET to relace the diode. I haven't seen any
>> that
>> use a single MOSFET for both functions.
>> I.e. for a PMDC motor controller, instead of one FET and one diode, they
>> use a high side FET and a low side FET.
>>
>> I had assumed they'd do the same thing with three phase synchronous
>> rectifiers.
>>
>> --
>> If you send email to me, or the EVDL, that has > 4 lines of legalistic
>> junk at the end; then you are specifically authorizing me to do whatever
>> I
>> wish with the message. By posting the message you agree that your long
>> legalistic signature is void.
>>
>>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
> Efficiency in physics is defined as power out/power in. To increase
> the figure by 5% implies that you are getting 5% more work for energy
> in.
>
Ok sure, but even with that difinition, you can't get a 5% improvement to
something that is already 99% efficient.
P.s. I missed this point in the text, but indicated the same reasoning in
the equations.
>> >
>> >> 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.
>>
>> Efficiency is very well defined; output divided by input. When
>> expressed
>> as a percentage you multiply the result by 100.
>>
>> (99-94)/99 =~ 5%
>> 99% - 94% = 5%
>>
>> The rules of math are very simply. Twice means to multiply by 2,
>> increasing something by 5 means to add 5.
>>
>> Perhaps the rules are different where you were educated, however, I
>> thought the rules of mathematics where universal.
>>
>> As has already been pointed out, by your rules if someone was to claim
>> they had produced a solar cell that was twice as efficient as a 10%
>> efficient cell, it would have to be 55% efficient.
>> After all the losses on a 10% cell are 90%, so 1/2 of 90% = 45%, since
>> you
>> are claiming that doubleing efficiency means the same thing as cutting
>> losses in 1/2
>>
>> Unless you are claiming that the rules change depending on your mood or
>> desired outcome? I find it hard to believe that any system of
>> mathematics
>> has rules like that though.
>>
>> >
>> > So what happens if I improve already 99% efficient design and make it
>> > yet 5% more efficient [5% improvement of that 99% gadget]?
>>
>> But that is NOT possible, at least not in this universe.
>> 99% + (.05 * 99) =~ 104%
>> There is no way you can improve a 99% efficient gadget by 5%.
>>
>> You can reduce it's losses by 5%. But that is NOT THE SAME as improving
>> it's efficency 5%.
>> 1/2 does NOT equal 2
>> 1/5 does NOT equal 5
>>
>> > It's percentage of percentage Peter. Unless I misunderstood you,
>> indeed
>> > appears like common misconception but on your part. Please re-think
>> > or elaborate.
>>
>> I don't know how I can put it more clearly. If you are still having
>> trouble with these concepts, I'd suggest visiting a library and reading
>> a
>> textbook on percentages
>>
>> --
>> If you send email to me, or the EVDL, that has > 4 lines of legalistic
>> junk at the end; then you are specifically authorizing me to do whatever
>> I
>> wish with the message. By posting the message you agree that your long
>> legalistic signature is void.
>>
>>
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
I've never magnetized using the motor, I would think
the winding distribution in the rotor is not optimized
for maximizing the field strength properly.
In our fixtures at work with have an iron return path
that the magnets are slipped over and a special
winding with very low turns. This type of magnet
could probably be charged with 200-300 amps. Some of
our neodymium magnets require over 1000 amps to charge
(heck, that's a poor launch current for the White
Zombie!!!).
A generated voltage test would be a good way to see if
your magnets are damaged.
--- Jeff Major <[EMAIL PROTECTED]> wrote:
>
> Rod, Mark,
>
> To test for demagnetization, you could run a
> generated
> voltage test, couldn't you? Drive the motor at a
> set
> speed and measure terminal voltage. Then proportion
> up to nameplate (or original no-load rpm) and if the
> voltage is a lot less than 24, opps, demagged. Then
> what? Could you remag by turning brushes 45 degrees
> and pulsing with a couple hundred amps?
>
> Sticky brush is also possible problem.
>
> Jeff
>
>
>
> --- Rod Hower <[EMAIL PROTECTED]> wrote:
>
> > If the motor was REALLY hot on 24Vdc there's a
> good
> > chance you demagnetized the PM field or at least
> > weakened it to the point of having much less
> > performance. If this is the case, I would think
> it
> > still gets pretty warm at 18Vdc. Also make sure
> > that
> > the brushes are properly seated on the commutator
> > and
> > not sticking in the holder.
> >
> > Rod
> > --- Mark Hastings <[EMAIL PROTECTED]> wrote:
> >
> > > I have a 4 brush 24 volt 1.5 PM motor on my 22"
> > > mower.
> > > I had run it initially on 24 volts but it got
> far
> > > too
> > > hot. I now run it at 18 volts and it worked for
> a
> > > couple mows.
> > > However now it just has no power at all. Any
> tall
> > > grass and it bogs down incredibly like the
> > batteries
> > > are dead. I even tried putting it back to 24
> volts
> > > and
> > > get the same results. Does this sound like I
> > ruined
> > > the motor in my initial runs at 24 volts? It is
> > > almost
> > > as if the batteries are dead. They are freshly
> > > charged
> > > batteries along with a brand new set of freshly
> > > charged batteries I just purchased.
> > > It had been cutting wonderfully but now I can
> > > hardly
> > > use it.
> > >
> > >
> >
> >
>
>
>
>
>
____________________________________________________________________________________Pinpoint
> customers who are looking for what you sell.
> http://searchmarketing.yahoo.com/
>
>
--- End Message ---
--- Begin Message ---
Hello to All,
--- jerryd <[EMAIL PROTECTED]> wrote:
You forgot an important number, it took only
140-150
wthr/mile for it's trip!! Not bad for an EV
breathing down
the 11 sec 14 mile bracket!!
Yes, I agree that it's pretty good efficiency for such a powerful car,
but remember the drive was at slower speeds through a 35 mph posted area
and a 45 mph posted area. It's easier to get good numbers driving
slower. As you know, whrs per mile go up at highway speeds as aero drag
comes into play, and highway speeds are usually the way whrs per mile
are figured.
White Zombie's twin 'Blue Meanie' has the losses of a tranny to deal
with, but weighing less at 2340 lbs. and with its narrow LRR tires
pumped up to 50 psi, it gets about 165 whrs per mile at a steady 60 mph.
White Zombie has no tranny losses, but it does weighs 240 lbs. more and
has those not-so-range friendly fat rear tires plus the drag of a Ford 9
inch differential's inefficient (but very robust) offset pinion. I'd
guess that with the rear tires pumped up to 35 psi (drag racing psi is
lowered to ~ 16) White Zombie will probably consume 180-190 whrs per
mile at 55-60 mph. That's still a good number, and I bet it's way more
efficient than any other street bodied, street legal 12 second drag car
that runs on dino juice.
See Ya.....John Wayland
--- End Message ---
--- Begin Message ---
Victor, if you want to redefine well known terms, knock yourself out.
You'll probably have to learn to accept the fact that most people are
going to be confused when you do so.
> Mark Karatovic wrote:
>> Efficiency in physics is defined as power out/power in. To increase
>> the figure by 5% implies that you are getting 5% more work for energy
>> in.
>
> Or the same work for 5% less energy in. We already settle on this.
>
> I only associate efficiency with losses because they are always
> inversely dependent: more losses = less work for the same input
> = less efficiency. Halving losses does not double efficiency
> mathematically, but it gets you exactly half way between current
> efficiency and 100% efficiency. If it was 90% it becomes 95%.
> You halved your losses. Of course you didn't double output,
> but you got it half way (to 95%) to the ideal maximum it can
> theoretically be (100%).
>
> My math is simple: 100% in and 90% out means 10% losses.
> Half the losses to 5%. Now 5% more can contribute to the useful
> output, and output is 90+5=95% of the input. 95% is HALF WAY
> between former 90% and ideal 100%. Half way is 50% of what
> you can ever do, (going 100% would be adding entire 10% to useful
> output and so have 0% losses which is impossible). I didn't use
> physical definition of efficiency, which is strictly speaking a mistake.
> Sorry, it's difficult to express exact way of thinking let alone
> assuring grasping by others.
>
> Peter wrote:
>>> But that is NOT possible, at least not in this universe.
>>> 99% + (.05 * 99) =~ 104%
>>> There is no way you can improve a 99% efficient gadget by 5%.
>
> There is - you can improve any efficiency gadget by anything from
> near 0% to near 100% *of what it takes to make it 100% efficient*.
>
> Depends how you define it:
>
> In your example your gadget is 99% efficient. 1% is losses.
> Make this obvious: you feed 100W in and get 99W out. 1W is loss.
> I was implying *this 1W* is 100% to work with (not entire input is
> 100% as is correct per physical definition): if you convert
> entire lost watt to useful output you removed 100% (all possible) losses.
>
> So you certainly can recover less than 100% of possible 1W recovery,
> for instance 5% or 50% or whatever. Again, 100% is only remaining 1 watt
> (1% of original input), not entire input, I was trying to describe it
> that way.
>
> So if you remove 5% losses you removed 50mW. If you removed 50% (of that
> watt) you removed 500mW which is 50% "improvement" compare to what it
> can possibly be.
>
> In physical terms improvement is 0.5% because you take whole input as
> 100%. Again, I was trying to explain that I took only losses as 100% to
> work with. I could sure stick to second way to look at the same thing
> (strict physical definition that 100% is entire input, not remaining
> losses, but chose not to. Doesn't mean I don't know about it it or don't
> understand it. I agree: difficult to express this, let alone assure
> others can grasp it.
>
> But this is not important since no one on this list cares how I
> (or anyone for that matter) think; it's a place to discuss EVs,
> not personalities. Why am I trying to convince you that I know this
> stuff well enough that it serves me flawlessly for years? I really
> shouldn't.
>
> You're right, I'm wrong. No problem.
>
> Let it die.
>
> Victor
>
>
--
If you send email to me, or the EVDL, that has > 4 lines of legalistic
junk at the end; then you are specifically authorizing me to do whatever I
wish with the message. By posting the message you agree that your long
legalistic signature is void.
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
But most implementations add 6 more power semiconductors; 6 diodes
across each switch. These allow you to do regen.
Dale Ulan wrote:
You need those diodes anyways, so that the inductance of the
motor creates an averaged current (the low-frequency AC component)
out of the 5-20kHz PWM signal applied. Without those diodes it'd
blow up even when motoring.
No; there are controllers that don't have them. The old SCR controllers
didn't have them except when regen was needed (SCRs aren't harmed by
reverse voltage; they just block current flow).
With MOSFETs, the diodes are there whether you like it or not. With
IGBTs, the diodes have to be there or the IGBT will be destroyed by
incidental reverse voltage.
--
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
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I have a used but not abused Leeson heavy duty commercial treadmill PM DC
motor I am going to be putting up on ebay, but thought it might be considerate
to post something on the list first.
It is rated at 1.5 HP and 90 V, but can run at higher voltages (which it does
on the treadmill with a pm controller). This is NOT a cheesy cheap throwaway
like you see offered a lot. It actually has bearings that will last and not
wear out quickly in EV applications. Runs fine and is quiet. Can also be used
with PM to slow down your band saw or power tool applications. (using one like
it for that purpose now).
Can be used for Air conditioning. I was going to do so originally, but am
going with a serpentine belt drive for my A/C and P/S. I gave $100 for it, but
will accept that including shipping in CONUS only if anyone is interested.
Email me if interested and I can send exact model number (I am not at home
right now) and a photo, dimensions, etc.
Mark Ward
95 Saab 900SE "Saabrina"
www.saabrina.blogspot.com
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So, doing the math....
165Wh per mile.
38 KWh per gallon_energy.
38000/165 = 230 mpg_energy.
$.10 per KWh.
$3.10 per gal.
== 31kWh per gal_$$
31000/165 = 187.87 mpg_$$
I'm not a mathemetician. I hope I didn't screw it too bad. I'm sure it will be
corrected if I did. ;-)
I will take any corrections as a learning experience, maybe improve myself 5%
while I'm at it ;-)
--
Stay Charged!
Hump
I-5, Blossvale NY
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of John Wayland
> Sent: Friday, May 25, 2007 10:33 AM
> To: [email protected]
> Subject: Re: Fast and Eff!!! Re: White Zombie gets to 'test' drive
> Lithium!
>
> Hello to All,
>
>>--- jerryd <[EMAIL PROTECTED]> wrote:
>>
>>
>>>You forgot an important number, it took only
>>>140-150
>>>wthr/mile for it's trip!! Not bad for an EV
>>>breathing down
>>>the 11 sec 14 mile bracket!!
>>>
>
> Yes, I agree that it's pretty good efficiency for such a powerful car,
> but remember the drive was at slower speeds through a 35 mph posted area
>
> and a 45 mph posted area. It's easier to get good numbers driving
> slower. As you know, whrs per mile go up at highway speeds as aero drag
> comes into play, and highway speeds are usually the way whrs per mile
> are figured.
>
> White Zombie's twin 'Blue Meanie' has the losses of a tranny to deal
> with, but weighing less at 2340 lbs. and with its narrow LRR tires
> pumped up to 50 psi, it gets about 165 whrs per mile at a steady 60 mph.
>
> White Zombie has no tranny losses, but it does weighs 240 lbs. more and
> has those not-so-range friendly fat rear tires plus the drag of a Ford 9
>
> inch differential's inefficient (but very robust) offset pinion. I'd
> guess that with the rear tires pumped up to 35 psi (drag racing psi is
> lowered to ~ 16) White Zombie will probably consume 180-190 whrs per
> mile at 5
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Thanks for the help everyone. I think I have it
working better now. I've still got some things that
need tweaking, but yesterday I was able to get plenty
of power out of it. I had it up to about 400 amps,
which is about what I was looking for.
It still doesn't seem to be working like it's supposed
to. The first 1/2" or 1" of pedal travel doesn't do
anything, and then it kicks in. Not to mention, it
says in the manual that 1/2" of travel is about
right... I have mine going well over an inch, maybe
two. I'm going to try the calibration for max throttle
again later today and see what it does. I'll also do
it in the dark, so I can see flickers from the light.
Thanks again for the help.
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
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I added the original software for NiFe and NiCd
batteries (the .asm files can be opened as text).
I also included charge parameters based on temperature
and how much to overcharge the batteries based on
A*hrs used.
http://autos.groups.yahoo.com/group/tevan/files/
Regarding Mark Hansons original question, check out
the file 'ovr_chg.xls'
Rod
--- Jerry McIntire <[EMAIL PROTECTED]> w
--- "David Roden (Akron OH USA)" <[EMAIL PROTECTED]>
wrote:
> > The manual says to final taper current at 7.5A
> but
> > I think that's a bit much, I'm at C/40 4.5A and
> they gas
> > quite a bit.
>
> That's their nature - they like to burp and belch
> and bubble. You don't taper-
> charge Saft nicads, it's constant current all the
> way, at least if you follow
> Saft's instructions.
>
> They tell you to start a timer and charge them 0.2C
> (36 amps) constant
> current to threshold voltage (8.0 v/block). When
> that happens you reduce the
> current to 1/5 the previous value (7.2 amps) and
> reverse the timer. When the
> timer counts down to zero you have your 20%
> overcharge and you shut off.
>
> There are periodic equalization cycles,
> commissioning charges, and a
> watering cycle, but the above is all it takes for
> daily cyclic use. Dead easy.
>
> IIRC, Rod Hower developed a somewhat different
> algorithm for the STMs in
> the TEVan, and he might chime in here.
>
> If you don't have the manual for your STM5-180s,
> snag it here :
>
> http://evdl.org/docs/STM5-180tech.pdf
>
>
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I think a loud audio system playing ICE roaring noises at launch, followed
by throwing rod or blower explosion noises, then silence, except that the
car keeps going, would be a riot. We want publicity? That might do it :).
You could substitute jet take off noises, shot from a gun noises, horse
galloping, rubber band noises (boing!), calvary bugle calls, HEE HAA!, you
name it :). Seriously, I've heard that one reason that Turbo motors are
legislated against (rules disadvantages) is that they are too quiet and
don't draw the crowds.
Marty
----- Original Message -----
From: "Chuck Hursch" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, May 23, 2007 4:11 PM
Subject: Re: PIR June 29-30 EV drag racing?
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: <[email protected]>
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/
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