EV Digest 2459

Topics covered in this issue include:

  1) RE: Amps Volts can Kostov take?
        by "Roger Stockton" <[EMAIL PROTECTED]>
  2) RE: Amps Volts can Kostov take?
        by "Roger Stockton" <[EMAIL PROTECTED]>
  3) Re: Amps Volts can Kostov take?
        by Rich Rudman <[EMAIL PROTECTED]>
  4) Re: 1kW Hydrogen Fuel Cell $5995
        by Rich Rudman <[EMAIL PROTECTED]>
  5) Re: Amps Volts can Kostov take?
        by Rich Rudman <[EMAIL PROTECTED]>
  6) RE: EVs - how to charge without a private garage
        by Lin Tse Hsu <[EMAIL PROTECTED]>
  7) Re: Alternator/ motor setup
        by Michael Shipway <[EMAIL PROTECTED]>
  8) Re: Silent Running (George Jetson)
        by "Roy LeMeur" <[EMAIL PROTECTED]>
  9) Re: EDISON DISALLOWS CONDUCTIVE CHARGING ON EV TOU METERS!
        by michael bearden <[EMAIL PROTECTED]>
 10) Re: OT (But Energy and Beer Related)
        by "Joseph H. Strubhar" <[EMAIL PROTECTED]>
 11) Re: Alternator/ motor setup
        by [EMAIL PROTECTED]
 12) EDISON DISALLOWS CONDUCTIVE CHARGING ON EV TOU METERS
        by Marvin Campbell <[EMAIL PROTECTED]>
 13) Racing with NiCads (was: Surplus aircraft nicads)
        by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
 14) PWM "tuning" (was: Silent Running (George Jetson))
        by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
 15) RE: EDISON DISALLOWS CONDUCTIVE CHARGING ON EV TOU METERS
        by "Walker, Lesley R" <[EMAIL PROTECTED]>
 16) Corbin Sparrow A C Controller
        by "Thomas Shay" <[EMAIL PROTECTED]>
 17) RE: Amps Volts can Kostov take? / Controller current.
        by Otmar <[EMAIL PROTECTED]>
 18) Re: Corbin Sparrow A C Controller
        by Otmar <[EMAIL PROTECTED]>
 19) Re: Silent Running
        by "Tony McCormick" <[EMAIL PROTECTED]>
 20) Re: Silent Running (George Jetson)
        by "Tony McCormick" <[EMAIL PROTECTED]>
 21) Re: EDISON DISALLOWS CONDUCTIVE CHARGING ON EV TOU METERS
        by "Lawrence Rhodes" <[EMAIL PROTECTED]>
 22) Re: Silent Running
        by "tgleeman2" <[EMAIL PROTECTED]>
 23) RE: Silent Running
        by "Walker, Lesley R" <[EMAIL PROTECTED]>
 24) Re: OT: Silent Running
        by Lonnie Borntreger <[EMAIL PROTECTED]>
 25) Re: OT Efficient Dehumidification (was: But Energy and Beer Related) 
        by Geoff Shepherd <[EMAIL PROTECTED]>
--- Begin Message ---
Peter VanDerWal wrote:

> FWIW the 600 amp rating on motor controllers is motor 
> current, not battery current.

While this is approximately true for Curtis controllers, it is not true
for DCP, Auburn, and EVCL controllers.  These controllers are spec'ed
for battery current and can deliver substantially more current into the
motor, at least for brief periods.

The "600A" controller in question is almost certainly a DCP600 Raptor
since I recall Damon once posting that it had a peak motor loop current
of about 3x its nameplate battery current rating.

Cheers,

Roger.
--- End Message ---
--- Begin Message ---
Peter VanDerWal wrote:

> Umm, I think you have a slight misunderstanding of series 
> motor controllers.  If they only list one number (i.e. 600 
> amp) then this means 600 MOTOR amps.  Battery current is 
> always the same or less (usually less) than motor amps.  
> There might be an exception to this but I'm not aware of one. 
>  The guys building racing controllers will often have 
> different pack and motor limits, but they usually list both.

Nope, David has it right, as long as he isn't considering a Curtis
controller ;^>

I believe the EVCL Godzilla allows both battery and motor current limits
to be adjusted, but I think it is still nameplated according to the
maximum battery current.

> Let's take a hypothetical racing controller, say 1200 amps at 
> 336V.  At launch the motor is stalled and current jumps to 
> 1200 amps...at a couple volts.  The voltage is too low to 
> fireball, but as the motor spins up current stays at 1200 
> amps but the voltage climbs.

... and eventually the motor voltage climbs to the point that more than
the available [loaded] pack voltage is required to continue forcing full
current into the motor.  At this point, motor voltage=battery voltage
and motor current=battery current; you've just come out of current
limit.  Assuming there is sufficient power available to continue
accelerating, RPM continues to build, and so motor current continues to
drop.

>  This is when you get into the 
> danger zone, sooner or later the voltage will get high enough 
> that 1200 amps will cause a fireball.  If you've built the 
> motor right this voltage will be higher than your pack can 
> deliver when under a 1200 amp load.

The danger zone extends higher than this, though.  The motor voltage at
these extreme currents is likely to be low enough that the fireball
danger is actually not that great, and the greater risk may be when
applying something like 500A at 240V+ at the end of the track even
though the motor survived 1200A+ (at <100-150 motor volts, say) earlier.

Cheers,

Roger.
--- End Message ---
--- Begin Message ---
Roger Stockton wrote:
> 
> David Dymaxion wrote:
> 
> > > >I think
> > > >alot of the stress the motors get is from current multiplication.
> > > >Getting the same torque for less motor current I'm hoping gives
> > > >good power without fireballing.
> 
> and later:
> 
> > I'm planning on
> > staying in known voltage regions (240 to 336 V), and maybe
> > twice "regular" current (but only 1/2 of Wayland current)
> > levels, but with sepex hope that motor current is actually
> > more modest than a "600" amp controller doing 3x current
> > multiplication.
> 
> I'm not sure I am following your reasoning... the mechanical power
> output by *any* motor must be less than the electrical power input to it
> (volts * amps); how do you expect to get comparable power out of a
> sep-ex motor unless you provide it with comparable input power as the
> series wound machine requires?
> 
> At low motor RPM, the motor voltage will be low and the current high;
> this is why the current multiplication of the "600" amp controller
> results in good low end torque.  If you reduce that motor current by a
> factor of 2 you have just cut your power in half and lost your low end
> torque.  I suppose it could be argued that with sep-ex you could pour
> the amps to the field but limit the armature current to spare the
> brushes/commutator and in doing so perhaps get a smaller loss in power,
> but I would be inclined to poll performance EVers like Rich Rudman, etc.
> and find out if series motor brush/commutator life in spirited street
> use is nearly the issue you seem to think it is before going this route.
> 
> I believe that fireballing becomes a concern mainly when high voltage
> and current are applied to the motor simultaneously (what "high" means
> will vary from one motor make/type to the next, and what constitutes
> "high" current may depend on how high the motor voltage is at the time).
> The high current multiplication is only provided at low motor voltages,
> and motor voltages only remain low until the RPM pick up, so it seems
> unlikely that current multiplication of the controller is going to be a
> significant factor in the probability of fireballing a given motor.
> 
> Cheers,
> 
> Roger.

Ok here's the way I take the Kostov 11 incher. I have one in the Fiero.
With the Raptor in it the Comm "sings"
at about 800 motor amps, and about 5000 rpm. I take this to be insipent
arcs. READ NOT good but not leathal.
This is with 156 volts. Brush wear is un known. I havn't taken it apart. 
        So with interpoles, stay below 800 amps. Wayland had 336+VDC on his and
1400 motor amps. With interpoles you have to stay close to the design
limit or the timing correct efforts become moot, and damage results.
What helps at 400 amps hurts at over some given point, I say that is 800
amps. My guess would be the motor is good and safe at under 800 amps and
up to 288 to 312 volts. Note that both numbers are about 2x the expected
design levels. AND not anymore.
        The improvemnts done by Warp, add mechanical robustness, but NOT
electrical. The fields and the comm and the interpole setups are the
same, so you have the same arc limits, but a much higher RPM withstand
ability. Your brushes will handle more amps, but, may not reduce the 800
amp arcing point at all. So... What do you want your motor to do??? Spin
like heck??? OK, you Want to stuff 2000 amps into it, better keep your
rpm down.
        There are other issues, but they may not come into play. I would love
to dyno a Warp motor and see the effective improvments. Since they are
cheaper that AvDC right out of the box.... I would head in this
direction for serious racing and abuse.  
-- 
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
Matthew Muelver wrote:
> 
> On Thursday, December 5, 2002, at 12:25 PM, Edward Ang wrote:
> > I was thinking may be one of these sitting on the back
> > seat.  It would be cool to charge the pack while
> > shopping at locations without public charging
> > stations.
> 
> Talk about a range extender!  Why not just plug your PFC-20 into it and
> drive 'till the H2 runs out?  Actually, you'd be able to keep going on
> "reserve" (your normal pack capacity) until you could find somewhere to
> fill 'er up.  Of course, to do this you'd probably need more than one,
> and probably a bigger H2 storage unit than what it comes with.
> 
> > Or, if we could generate hydrogen at home and refuel
> > the unit, we won't even need charging at work.  A
> > 9-hour workday could put 8-9kWh back to the pack for
> > the trip home.  Then, we recharge the pack and refuel
> > the fuelcell with hydrogen at night.
> >
> > Ed Ang
> 
> We could develop our own homebrew H2 refilling stations!  Can you see
> the first cross-country fuel cell vehicle being an EV conversion
> refueled at private residences on its way from one coast to the other?
> Sounds like fun!  Isn't there a way to make H2 from water using solar
> power?
> 
> Matt
> --
> If you're reading this, chances are your either:
> A. A Honda freak, just like me.
>         '01 M.C. Blue Insight 5 spd. #1898, 57.1 LMPG @ 24,900 mi.
> B. A Mac Addict, just like me.
>         Dual-1GHz PowerMac G4, iBook 800MHz 12.1"
> or
> C. An EV freak, just like me!
> :-)
> <http://www.thewbstreetteam.com/click.php?id=5&memberID=387>
A significant efficientcy gain would be to remove the boost inverter,
and drive the PFC20 direct with the DC from the Fuel cell stack. Use the
PFC20 as a DC/DC boost converter that boosts just high enough to charge
the battery stack. Assume a 5 to %15 reduction in I2R losses in the Fuel
cell DC rail.

Sooner or later this stuff will find it's Way to my desk.... With my
luck it will have a 14 page NDA taped to it.... keeping me from telling
you all the Good stuff. Sigh... 

-- 
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
Peter VanDerWal wrote:
> 

> 
> FWIW the 600 amp rating on motor controllers is motor current, not
> battery current. I.e. the battery current will usually be less than 600
> amps except for the brief moment when the controller comes out of
> current limit, at which time battery current will equal 600 amps and
> then start to fall.

I dissagree. DCP controllers can have significant motor loop current
multiplication. On the Raptor 1200s you could get 1800 amps for short
bursts . On the Raptor 600s with 1000 amp motor loops, you can see that
the diode path is larger than the battery side path. You can and doo get
2 to 3x battery to motor loop gains.
        My AC stuff can make 10x at low power levels. AKA %10 PWM can have a
10x increase from the battery to the motor side. Yes they make for some
torqey motors.

-- 
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
Here's a question from a non-evdl'er, which could use
some good
feedback
from the experiences across the list. Please respond
back to Randy's
email
address (randynerve-at-nethere-dot-com) and cc the
list, since these
are
common questions by those who need to charge but lack
a private
garage.
Thanks.


Hi,

I am strongly considering purchasing an EV. However,
there are
potential
roadblocks in my plan and I wonder if you answer my
questions. 

I live in New York City in an apartment building. I do
not own a home
with a
garage, meaning I would have no means of plugging in
the EV as I'd be
parking on the street. Is there such a thing as a
charger that plugs
into
the wall, stores electricity, and then can be placed
inside the
vehicle when
not in use, plugged into the vehicle, allowing the
vehicle to charge? 

Or, if such a thing does not exist, can a solar panel
be installed on
an EV
to gather sunlight to charge the batteries, thereby
eliminating the
need to
plug in? 

Are there any ways around the problem of owning an EV
as an apartment
dweller? I look forward to your response.

Thank you,
Randy Stern

Hi Randy.  This is one of the Achilles heel's of
electric vehicles,
and often cannot be solved.  Despite all the talk and
hot air, it
is sometimes just difficult to find an electric outlet
to charge
the car from.

The ability to charge is very much based on your
situation.  Lots
of neighborhoods with cold climates have block heater
outlets.  You
may be able to hack into a line somewhere if none of
your neighbors
don't have anything against you.  Sometimes,
apartments have lighting
circuits which are energized at night.  But, avoid
digging around
under manhole covers where there are oil filled 100 kV
lines.  These
really pack a zap.

In countries such as Singapore and China, where
electric bicycles
could be beneficial, the lack of streetside charging
and security
are the EV's biggest enemies.  You may think that
those Chinese
could just lug their bicycles into their flats, but it
seems that
all my friends live above the 4th floor, and the
stairways are
narrow cold concrete.

The only thing that comes close to your request is an
electrolytic
zinc regenerator.  It plugs into the wall and
regenerates spent
zinc fuel cell oxide back into zinc.  The availability
of these is
very tenuous, but keep your eyes open.  Maybe in the
distant
future...

Meanwhile, keep the EV idea in mind for when you move
to a more
"friendly" location, since that may occur sooner.

__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
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--- End Message ---
--- Begin Message ---
Lee Hart wrote:
> 
> Michael Shipway wrote:
> > EVA/DC toured the Electromotive factory a couple of years back, where
> > they where building such a system. It was a very smoothly assembled
> > system that could be retrofitted onto any vehicle that had the space.
> > ... http://www.electromotive-inc.com/hybrid/index.html
> 
> Very impressive! Is it 'unobtainium', only available to large OEMs that
> pay substantial licensing fees? Or, is it actually available as a
> product for small customers (as their website implies)?

When we toured, they seemed to have a system ready to sell in quantities
of one.  It seemed to be an extension of their semi-custom engine
control systems.  
This consists of a couple engine sensors, most notablely a very accurate
crankshaft angle tracker, individual electronic ignition coils for each
plug, and a computer to fire the plugs with 0.1 degree timing accuracy.
Then there are mods to the fuel injection system.

The Hybrid system was all that, plus some more software, a motor,
batteries, a regen controller and an I/O device to connect it to the
computer.

I'm sorry but I don't remember what kind of motor they where using.
Batteries where Hawker Genesis 12 volt, 16ah.
They where using a Zapi controller, but having some problems and where
looking at another type, though I forget which.
I've a vague memory that the price was somewhere between $3,000 and
$5,000.
Does this sound right?

Needless to say I was impressed overall.

They had it installed in several cars at the time and where working on
putting it in an old motorhome.  

As I said before, this is my memory from a couple years ago, and I've
not talked to them since.  I'll try to remember to call them tommorrow
and get updates.

-- 
Michael Shipway
[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Jon \"Sheer\" Pullen wrote:
What would people be willing to pay for a board that they could buy with a
number of samples preloaded into it along with the ability to play those
samples at varying rates depending on output from VSS?

Board would need to be combined with a inexpensive power amplifier and
speaker to actually produce engine sounds..

Victor Tikhonov wrote:
Try John's stereo audio inputs... Isn't it fun?



Hey Sheer!

You really gonna do it?

You already know that I think that this is a great idea. :^D

I believe there is a wide market for this.

All kinds of toys could use it, the golf car market could be substantial.
(if they will buy bodies that look like Mustangs, VWs, and Rolls Royces they will buy anything.)
Anything that spins could be made to work with an RPM pick up.
(Kid's PowerWheels)

Make it run off 12vdc and easy to jack into a sound system.


Top Ten Sounds?

1- George Jetson's car (I bet this would be number one with EVers)

2- Nitro burning top fuel dragster

3- Indy car

4- Jet aircraft

5- Helicopter

6- Curtis 1231 :^D

7- Model T Ford

8- Big-Bore Crotch Rocket

9- Locomotive (steam, w/whistle)

10- Briggs and Stratton Mini-bike


OK, some of these ain't the greatest, anybody else got some good ones?







Roy LeMeur Seattle WA

My Electric Vehicle Pages:
http://www.angelfire.com/ca4/renewables/evpage.html

Informational Electric Vehicle Links:
http://www.angelfire.com/ca4/renewables/evlinks.html




_________________________________________________________________
Tired of spam? Get advanced junk mail protection with MSN 8. http://join.msn.com/?page=features/junkmail
--- End Message ---
--- Begin Message ---

Marvin Campbell wrote:

> So Edison finally came out and installed my TOU meter but you're gonna LOVE
> this:
>
> They won't allow me to charge my Soleq EVcort on that circuit.
>
> That's right.
>
> They say conductive charging is not allowed within the guidelines of their
> EV charging program because, and I quote a Edison rep, "You might go plug
> your dryer into that circuit and use that 4 per KWH power to do your
> laundry, or something".

In Northern California, I can't get PG&E to come out and install my TOU meter
on the line that my solar panels are tied into...but they raced out here to put
the TOU meter on my EV charging line.  I just got a bill for that - one month
cost $10.65.  I charge between midnight and 7am when the rates are the absolute
lowest.
Michael B.
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Thursday, December 05, 2002 9:12 AM
Subject: RE: OT (But Energy and Beer Related)


> Andre
>
> don't know where you live.
> Wood is just as bad as coal.

Whoa, not so fast - this isn't true at all! Coal is much more polluting than
most kind of wood, and doesn't smell nearly as good, either!!

Joseph H. Strubhar

E-Mail: [EMAIL PROTECTED]

Web: http://www.gremcoinc.com
--- End Message ---
--- Begin Message ---
In a message dated 12/5/02 6:35:18 PM Pacific Standard Time, 
[EMAIL PROTECTED] writes:

<< I've a vague memory that the price was somewhere between $3,000 and
 $5,000.
 Does this sound right? >>

I believe their stand-alone FI and ignition system by itself costs between 
$3000 and $5000. I'd have to guess that's a bit low for the whole hybrid 
enchilada.
Sure looks slick tho....
While were talking hybrids, I think we are going to see a lot of electric 
motor assist systems as soon as the 42 volt electrical system comes on line.
The Siemens starter/generator will supposedly be capable of 10 electric hp. 
This style has the windings placed around the flywheel. 

back to quiet lurking...
Ben
--- End Message ---
--- Begin Message ---
I hadn't thought of that angle. My car presently uses a massive twistlock to
the "fuel" door and a 14-50 to the plug. Nice and simple.

It's worth a try.


> From: David Dymaxion <[EMAIL PROTECTED]>
> Date: Thu, 5 Dec 2002 15:42:31 -0800 (PST)
> To: [EMAIL PROTECTED]
> Subject: Re: EDISON DISALLOWS CONDUCTIVE CHARGING ON EV TOU METERS
> 
> Maybe it would reassure them if you had an avcon, that can't easily
> power anything but an EV, instead of a regular plug?
--- End Message ---
--- Begin Message ---


#1 Same available power either cold or warm, thus the 2 or 3 practice runs
will be the same as the actual elimination runs. Consistency is the name of
the game in bracket racing.

Increasing temperature will change the voltage a little and will tend to lower the internal resistance significantly. Also, flooded NiCads tend to be less efficient than lead acid AGMs, so it is possible they will overheat with fewer runs if you don't make a special effort to cool them.


#2 The pack I will be using will have enough extra amp hours to make at least
2 consistent runs thus I will not have to fully top the pack in between runs
to be consistent.
The internal resistance, and thus the voltage sag, goes up as the battery discharges. Thus, the second run without a charge will be a bit slower.


As the race day progresses the round winners have to come
to the line quicker (I have gotten caught in this trap a couple of times) and
sometimes have been directed back to the line immediately, this has spelled
doom for the Current Eliminator with the lead batts I was using. Topping of
the pack will be done at home or in the early rounds as time permits.
It might be best to make the pack easy to swap. If you can make the swap inside 12 minutes, your problem is solved.


#3 Some NiCads I have bench raced hold the voltage high throughout the run
making for Big mph#s. This really helps when bracket racing.
        I hope it all works out for you.

Question, I realize one should not have NiCads stored in the same room as
lead acid batteries the Current Eliminator resides in an enclosed trailer
with a pit cart powered by lead acids
I don't think there is a serious safety issue involved with storage of lead-acid and NiCad batteries in the same room. At least I've never heard of any major problems.

You would want to be sure that you did not mix up any of the funnels, bottles, or containers that you have used for the different electrolytes. It would be smart to keep them in a separate cupboard.







_ /| Bill "Wisenheimer" Dube'
\'o.O' <[EMAIL PROTECTED]>
=(___)=
U
Check out the bike -> http://www.KillaCycle.com
--- End Message ---
--- Begin Message ---
At 07:48 PM 12/5/02, you wrote:

Jon \"Sheer\" Pullen wrote:
What would people be willing to pay for a board that they could buy with a
number of samples preloaded into it along with the ability to play those
samples at varying rates depending on output from VSS?

Board would need to be combined with a inexpensive power amplifier and
speaker to actually produce engine sounds..
You already have the "amplifier" in an EV. Just alter the PWM frequency for the controller. You could program the controller to play any tune you like. It would get loudest at 50% duty cycle.




_ /| Bill "Wisenheimer" Dube'
\'o.O' <[EMAIL PROTECTED]>
=(___)=
U
Check out the bike -> http://www.KillaCycle.com
--- End Message ---
--- Begin Message ---
Marvin Campbell wrote:
> So Edison finally came out and installed my TOU meter but 
> you're gonna LOVE this:
> They won't allow me to charge my Soleq EVcort on that circuit.

Another thing to think about, maybe...

I just went poking around in Edison's web site (I wanted to know
what TOU stood for, turns out to be Time Of Use if anyone else
wants to know).  I found the documents that set out the details
and conditions of the special rates (there are two special EV
rates depending how much power you use, and the documents look
identical except for the numbers).
http://www.sce.com/NR/sc3/tm2/pdf/ce114-12.pdf for TOU-EV1
http://www.sce.com/NR/sc3/tm2/pdf/ce115-12.pdf for TOU-EV2

Under "Applicability" it says "Applicable to charging of electric
vehicles separately metered by the Utility [blah blah]".
It does NOT say "electric vehicles with inductive charging".

Special Condition #5 is the trouble spot. It says:
"Customers taking this service under this schedule shall have no
electrical interconnection beyond SCE's Point of Delivery between
electrical loads eligible for service under this schedule and any
other electrical loads".  In other words, only EVs are allowed to
plug in to this circuit, no driers or anything else.
Again, there is no mention of what sort of connector is to be used.
In fact nowhere in the document does it specify any type of
connector.

Two thoughts spring to mind (see caveat below):
1) Perhaps condition 5 could be satisfied by offering to sign
an additional document that says something to the effect that
"I understand that I may not use this circuit for any appliances
other than electric vehicles and I hereby undertake to observe
this requirement" in combination with using a different type
of connector to what your drier uses.

2) They have said that you can use the circuit to charge any
electric vehicles owned by you, but they are preventing you
from doing so by their insistence on using an inductive
connector even though that is not specified in your agreement
with them.
If there is no other legal document that specifies the inductive
connector, or allows them to specify it, maybe you could take
them to court for failing to provide a service that they have
agreed to provide.

CAVEAT: I am not a lawyer. I am not an American.  All I know
about the American legal system is what I have seen on TV and
on the Internet.  Seek advice from a real lawyer before doing
anything like this.

-- 
Lesley Walker
Unix Engineering, EDS New Zealand
[EMAIL PROTECTED]
"The secret to getting ahead is getting started.  The secret to
getting started is breaking your complex overwhelming tasks
into smaller manageable tasks, and simply starting on the
first one."     --- Mark Twain
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On the Corbin Motors' web site at 
http://www.corbinmotors.com/dailynews.html

they have announced arrival of a new A C controller and smart
charger and said these new items would be installed and tested
in a Sparrow soon.

Does anybody recognize these components?  Labels in the pictures
can't be read.

Several months ago there was considerable todo on their website
about new A C motors and fitting one to a rear swingarm.  So if they
now have controllers, they might not be far from having a working
Sparrow with an A C drive system.  It will interesting to see what
happens.

Tom Shay
--- End Message ---
--- Begin Message ---
While this is approximately true for Curtis controllers, it is not true
for DCP, Auburn, and EVCL controllers.  These controllers are spec'ed
for battery current and can deliver substantially more current into the
motor, at least for brief periods.

I believe the EVCL Godzilla allows both battery and motor current limits
to be adjusted, but I think it is still nameplated according to the
maximum battery current.
I figure I should speak up a bit here, since I know a bit about it. :-)

Just to clarify, the green box that I build is now known as a Cafe Electric Zilla, since the company that was EVCL is not doing much anymore.

The Current Zilla has a motor loop current limit of 1800 amps and the battery is limited to the same. It is true that the Zilla allows individual adjustment of both battery and motor current separately, as well as battery and motor voltage limits. I believe I'm still the only one offering that on a DC controller. But it still is primarily a motor current limited machine like the Curtis.

I have done a lot of math on this subject, and belive that the lack of motor current limit has been detrimental to the reliability of the Auburn and other controllers that do not primarily measure motor current. Sure, with a light vehicle, or one that has a transmission you can get away with it for a long time, but try running a heavy single ratio vehicle and the overload on the diodes shows up in a rude way.

The soon to be released Z2002 model of the Zilla is targeted to provide up to 2000 amps motor current at room temperature, but only 1800 amps battery current. At the moment I am working on the software to implement this. It's not that easy to do while still having reasonable headroom below the safe operating limits of the devices.

For those of you curious about it, I've posted a graph of the safe limits vs duty cycle.
http://www.cafeelectric.com/temp/pdf/Z2K400V.pdf
The curves that are low on the left are diodes, and low on the right are the IGBTs. The higher curves are lower temperatures. These are theoretical, and I'm sure my implementation will provide more headroom especially because it all has to be adjusted thousands of times per second as the duty cycle changes. No, I won't be exceeding 2000 amps :-) because there are other limiting factors as well.

Anyway, back to the point. My feeling is that a controller without a motor current limit (such as the Auburn and I think some of the DCP models) can be hazardous to its own health because nothing will limit the freewheel current at low duty cycle. The larger the diode section and the smaller the stall load, the better the chances of survival. Additionally a high power controller without an adjustable motor current limit can be detrimental to the motor, driveline and tires. So be careful of those unregulated bursts of "substantially more current".

As for the power that a Kostov can take, my impression from talking with others is that they do better with voltage than current compared to an ADC. The Kostov commutator has relatively little mass and so can overheat quickly at high current. I've seen dragsters that lifted bars pretty quickly without ever being held at stall. On the other hand, I've never seen a motor of this size take as much voltage without fireballing as a Kostov. As John says, they seem to have no trouble with 250V at the terminals.

As for the idea of pumping in more field current in a sep-ex to reduce the armature current, remember that this has limits too. I don't know what the limits are, but I have been told by experts that it is wise to keep the field strength in the armature and field roughly equal to promote good commutation. Lots of unknown territory here.

Anyway, it sounds like an interesting thing to consider. Maybe it would help if you start putting some numbers on the project, curb weight, gear ratios, acceleration desired, top speed etc. Then it may be easier to evaluate how much current and voltage would be required in various modes. Also, I believe Kostov makes a sep-ex machine. If you could get curves at various field currents you could extrapolate from them.

-Otmar-

http://www.CafeElectric.com/ Home of the Zilla.
http://www.evcl.com/914 My electric 914
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On the Corbin Motors' web site at
http://www.corbinmotors.com/dailynews.html

they have announced arrival of a new A C controller and smart
charger and said these new items would be installed and tested
in a Sparrow soon.

Does anybody recognize these components?  Labels in the pictures
can't be read.
Looks a lot like the kind of packaging that Curtis does. I've also heard that the AC division of Curtis is in Germany. Could be them.

-Otmar-

http://www.CafeElectric.com/ Zilla "Got Amps" Shirts now available online.
http://www.evcl.com/914 My electric 914
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Date: Fri, 6 Dec 2002 01:06:23 -0800
Subject: Re: OT Efficient Dehumidification (was: But Energy and Beer Related) 
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Mime-Version: 1.0 (Apple Message framework v548)
From: Geoff Shepherd <[EMAIL PROTECTED]>
To: [EMAIL PROTECTED]
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Message-Id: <[EMAIL PROTECTED]>

On Thursday, December 5, 2002, at 10:19 AM, Tim Clevenger wrote:

> I wish there was a cheap and energy-efficient way to get the moisture 
> out of vented air.  My electric dryer has to be vented outside, lest 
> the house turn into a sauna, and in the winter, you can see the heat 
> being wasted.

Condensing-type dryers do this. All the heat stays inside the machine. 
A blower circulates the air which is passed over/through a trickle of 
cold water. Like A/C evaporator coils, this dries the hot air by 
condensing the moisture out. The resulting water is periodically pumped 
out of the machine. It's a slower way to dry, but it works and uses a 
lot less electricity. My Equator washer/dryer takes about 90-120 
minutes to dry a load using a 1200 watt heating element on ordinary 120 
VAC, and the element doesn't stay on continuously since the heat stays 
in the machine more like an oven. Don't forget the conventional vented 
dryer also sucks heated air out of your home in addition to wasting its 
own heat.

I was thinking an even better way to do this would be with a Peltier 
array... there's your heat source and cold surface for condensing water 
all in a tidy, solid-state package.

This then got me thinking it might be a good way to provide heat and 
defrost for an EV (but not A/C - not efficient enough).

--
Geoff Shepherd
'98 Factory Ford Ranger EV
'00 Honda Insight
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