EV Digest 5339
Topics covered in this issue include:
1) Re: Crazy DC regen idea, thoughts, comments
by Lee Hart <[EMAIL PROTECTED]>
2) Re: A cleaner EV genset.
by "Peter VanDerWal" <[EMAIL PROTECTED]>
3) Re: Crazy DC regen idea, thoughts, comments
by Lee Hart <[EMAIL PROTECTED]>
4) Re: Crazy DC regen idea
by Jeff Shanab <[EMAIL PROTECTED]>
5) RE: Orb Carnage....
by Jeff Shanab <[EMAIL PROTECTED]>
6) Re: YAEVBA
by "ProEV" <[EMAIL PROTECTED]>
7) non-identical twin regen?
by Tom Watson <[EMAIL PROTECTED]>
8) Re: Crazy DC regen idea
by "jerryd" <[EMAIL PROTECTED]>
9) RE: 3kw genset for $315, Details
by "jerryd" <[EMAIL PROTECTED]>
10) Re: Crazy DC regen idea, thoughts, comments
by Lee Hart <[EMAIL PROTECTED]>
11) Re: Crazy DC regen idea
by Lee Hart <[EMAIL PROTECTED]>
12) adventures in electronics
by Fortunat Mueller <[EMAIL PROTECTED]>
13) Re: best donor car for 2000lb of lead
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
14) AC vs DC
by John Wayland <[EMAIL PROTECTED]>
15) Electric & Hybrid Vehicle Job Posting - San Diego
by "Jim Waite" <[EMAIL PROTECTED]>
16) Re: Crazy DC regen idea
by Doug Weathers <[EMAIL PROTECTED]>
17) Re: non-identical twin regen?
by Doug Weathers <[EMAIL PROTECTED]>
18) Re: AC vs DC
by "Dmitri Hurik" <[EMAIL PROTECTED]>
19) Choosing the right career (was RE: Low efficiency with light loads)
by "damon henry" <[EMAIL PROTECTED]>
20) Re: adventures in electronics
by "Philippe Borges" <[EMAIL PROTECTED]>
--- Begin Message ---
Lee Hart wrote:
>> Correct; close is good enough if you are just going to rectify the AC.
>> If you wanted to use it to run a 3-phase AC load it would matter, but
>> not for rectification.
Bob Rice wrote:
> This means as a regen feature? You're gunna rectify to DC anyhow?
Correct. The idea is to add slip rings to bring out the AC from the
windings of a DC series motor. Rectify the AC into DC, exactly as is
done in an automobile alternator. Use this DC to charge the battery.
> So the motor may hafta be a tad, couple inches longer? Hate to get
> rid of the fan.
You need the extra length for the slip rings. If you're modifying an
existing motor, the easiest way is to remove the fan and use its space.
You would need an external blower to replace it. An external blower is a
better idea for a traction motor anyway.
> How would ya set up a controller? After all, when you shut off the
> traction power, wouldn't the AC side you tapped off drop out, too?
Yes. The AC voltage at the slip rings is proportional to rpm x field
current. No field current means no AC voltage.
So, you would add a contactor that opens the connections to the brushes,
and reconnects the field so the controller is powering only the field.
The throttle pot controls the field current. Control it and you control
the AC voltage, and thus the regen current.
> As Lee mentioned a source of energency AC, but it would be tricky to
> regulate a series motor to about 60 Hz?
The classic application for a rotary converter is to put DC power into
the commutator, and take AC power out the slip rings. The peak of 120vac
is 168vdc; so if the commutator is powered at 168vdc you automatically
get 120vac out.
The frequency of the AC is determined by the rpm. You adjust that with
the field current. In the old days, they simply used a compound wound
motor, with the series field strength arranged so it neatly strengthened
the field just enough to hold the speed constant despite load changes.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Actually, propane /can/ burn cleaner than gasoline, but it's not a given.
Propane conversions can, and often do, pollute MORE than gasoline engines.
In fact most home conversions of automobiles ended up polluting MORE than
they did as gasoline burners which is why it is currently ILLEGAL to
convert a car to propane (in the USA) unless you are a certified converter
AND you have to get certification for every vehicle you convert.
> IMHO, Jeff has a good answer: Propane, which runs much cleaner than
> gasoline. http://www.epa.gov/otaq/consumer/fuels/altfuels/420f00039.pdf
> Propane conversion is my EVentual plan for the aircooled VW engine that
> will be reincarnated as a long ranger for the Karmann Eclectric. Not only
> will the engine run very cleanly and have reduced maintenance
> requirements, the old VW sewing machine will also produce plenty more
> power than even a mighty PFC 50 could transmit to the pack.
> See if I've made a leap of math here...
> At 60 mph pulling a trailer, I'll allow a hoggish 250 w/h per mile for the
> Ghia combo. That's 15 kW, only 1/3 the peak power of a 1600cc VW flat
> four. This would be easily supplied by a 20kw generator head, but I'd have
> to bypass the PFC with a Big Bad Boy on my 240 VDC system, or upgrade to a
> "PFC 70 " (70 amps in at 220 VAC= 15.4 kW).
> Fuel consumption would be @ 25% worse on propane, I figure 2.5
> gallons/hour instead of 2 (the Ghia reliably got over 30 mpg on the
> highway). That would still give a 4 hr run time on one 40 lb (10 gal)
> cylinder.
>
> Eh? -Jay
> www.karmanneclectric.blogspot.com
>
>
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--- End Message ---
--- Begin Message ---
Evan Tuer wrote:
> I think Lee is proposing that you could use the traction controller to
> power only the field (use a SPCO contactor to switch the armature out)
> and in the simplest form you'd just press the accellerator to get
> regen, with the "regen" switch thrown.
>
> But you could use a seperate, lower powered controller to feed the
> field independantly.
Yes. You need a lot of field current, but very little voltage; like 1v
at 500 amps. You can supply this with the regular PWM controller, but a
much smaller special-purpose controller could be used as well.
> When driving, you'd also have to disconnect the AC end I think, could
> use a simple SCR perhaps.
I'm not sure, but it may turn out that the AC bridge can be left
connected to the battery all the time. While "motoring", the armature
voltage is always equal to or less than the pack voltage; thus the
rectified voltage should always be less, and no regen current flows.
The "hitch" may be that the rectified AC voltage is less, but has a DC
offset that causes a current flow. Have to study it closer to see.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I like this idea!
To simplify the control, Would there be enough residual magnatizm since
the field is DC to power the field off of the regen energy?
So when the throttle is lifted the throttle closed switch is used via a
AC contactor to connect the 3phase sliprings and the recified output is
tapped with a resistor to give enough field voltage to keep the magnetic
field going, then when we press on the brakes, the resistor is shorted
with a lesser value to get more braking. Or would this be too abrupt?
Would the freewheel diodes in the controller mess with this?
--- End Message ---
--- Begin Message ---
I just had a strange idea/question. Could the concept of a bypass
regulator be used in another way
disclaimer, this would be a really good way to waste money.
Could a bypass be made that bypasses a battery when too much current is
asked from it?
like you have one battery in the string that can't keep up under hard
accelerations so it is shorted in such a way not to short the batttery
itself, an anolog version would be a SPDT relay which would drop out if
the voltage dropped below a threshold.
Your pack voltage would take a 12V hit but you keep going. Would this
get you down the dragstrip faster than having a low voltage sensor pull
back the current on the controller?
Now in a system of 25 12 volt cells, this is probably not much use, but
if I have 100 li-ion cells, or 1000s of D-cells this might become more
resonable.
could a bypass be made that lets the battery still contribute?
B1--200A---B2--100A----B3----200A---...
|_____100A__|
--- End Message ---
--- Begin Message ---
Jerry,
I didn't realize it was a 1 hour rate. I'd seen it on another batteries
webpage as 70ah at 20hr and didn't research it further. I've skimmed
through the links you sent, but didn't see where they mention what the
rate is. Or is there some other indicator that I'm missing which always
means 1hr rate?
The old Kokam specs all seem to specify the 1 hour rate. We (ProEV) tested
capacity by doing a 1 hour discharge cycle on each of the 95 cells we got
and all gave over 70 amp/hrs (range 71-78 amp-hrs). Here is the link to the
write up on our tests: http://www.proev.com/BatLog/Kkm0003.htm.
These were the SLPB 60460330. 70 amp-hrs at 1C. 5C continuous, 10C Pulse. I
think they were actually rated for 8C pulse but Kokam told us we could use
10C.
Kokam now offers two options in the 70 amp-hr cell:
High Energy SLPB 53460330 1C continuous, 5C pulse.
High Power SLPB 60460330H 5C continuous, 10C pulse.
They both seem to be rated as 70 amp-hr at .5C. That is the 2 hour rate.
The High Powered cells have the new cathode construction that gives the new
higher cycle life. I do not know why they now rate them at the two hour rate
rather than the one hour rate. My guess is that the changes they made to
improve cycle life and beef up high power discharge might have brought down
the capacity just a little. Rather than calling them something like the 68.5
amp-hr cells (at the 1 hour rate), they might have changed the rating to 70
at the 2 hour rate.
If you look at the SLPB 41205130H which is the High Power 7.5 amp-hr cell
(at .5C) and compare it to the SLPB 45205130P which is the Ultra High Power
7.2 amp-hr cell, it looks like they are basically the same size and weight
(one is a little thicker) but the Ultra High Power is rated for pulse
discharge of 20C. To get that 20C discharge capability, it loses 0.3 amp-hrs
capacity.
This is all from http://www.kokamamerica.com/kokam_catalog.pdf
Keep in mind that many types of batteries have 'calendar lives'. For
instance, the lithium polymer might have a calendar life of 5 years. So
even if the cells have not been cycled to death, they may die of old
age.
I wasn't aware of this. Do you mean "stored on a shelf not being used"
life or just regular wear and tear from being "alive" type of life
expectancy?
Maybe it is like dog years? ":^)
This is a very grey area! I would guess that 'alive' type of life would be
more useful but there are a million possible variables and how you define
the test will benefit some batteries and hurt others. Plus how do you test 5
year calendar life on a product that has been around for less time? Cell
construction is constantly being modified, so when you get a real answer for
a cell it is already obsolete.
Finally, how about some NiCad's? I know some listers have reported good
results with the SAFTs. They might be a nice step up from lead acid
without going too extreme on price.
Sure, send them on! Post here so Cowtown and others can grab them.
Would love to get part #, 1hr rate, cycle life, weight, dimensions, and
cost/supplier. A link to specs would be sufficient for most of the info,
but getting real-world prices (and other feedback) from people who have
actually purchased and used the batteries is invaluable.
I do not have any NiCad experience but I hope others will post.
Cliff
www.ProEV.com
--- End Message ---
--- Begin Message ---
hi
With all these posts on regen, twin motors and $315 generators, along
with my inability to understand how DC regen is accomplished , I got
to thinking;
"why couldn't you build a non-identical twin, motor/generator set-up
for regen..."
The generators it appears are quite inexpensive (read cheep) and the
complexity of building a DC regen is quite high. It could be set up
so as to get the higest efficiency regen possible and leave your
motor (which is prolly already made very efficient)alone. Also the
generator armature would act as a flywheel. I'm not sure if that is
good or bad thing though.
What do you think... any comments on how this could or couldn't
work??
Tom
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--- Begin Message ---
Hi Jeff, Lee, Jim and All,
----- Original Message Follows -----
From: Jeff Shanab <[EMAIL PROTECTED]>
To: Electric Vehicle Discussion List <[email protected]>
Subject: Re: Crazy DC regen idea
Date: Sat, 08 Apr 2006 08:51:18 -0700
>I like this idea!
>
>To simplify the control, Would there be enough residual
>magnatizm since the field is DC to power the field off of
>the regen energy?
Probably not though you need a low amount of mag,
weakened field, I'd believe so to get high enough voltage to
regen instead of a lot of field strength. Otherwise one may
need a boost converter raising costs.
Maybe adding a small neo mag to each field like a
compensating coil would give you enough so you don't need to
use the controller to energize the field, saving complexity.
Would that work? I could certainly use regen if it's
fairly simple.
Instead of a controller, maybe use a/couple of Cyclone
battery cells, recharged between regens, to power the field
cheaply. It's not like you regen for long usually.
As for slip rings, they could be easily made with some
copper pipe, a pipe cutter and some putty style epoxy to
support them on the shaft. One would need to roughen the
shaft, ect for some tooth to the epoxy. I'd use DC brushes
to handle the higher currents than most AC slip rings are
designed for.
Comments welcomed as I'm just learning this,
Jerry Dycus
>
>
>So when the throttle is lifted the throttle closed switch
>is used via a AC contactor to connect the 3phase sliprings
>and the recified output is tapped with a resistor to give
>enough field voltage to keep the magnetic field going, then
>when we press on the brakes, the resistor is shorted with a
>lesser value to get more braking. Or would this be too
>abrupt?
>
>
>Would the freewheel diodes in the controller mess with
>this?
>
--- End Message ---
--- Begin Message ---
Hi Jeff, Cor, John and All,
----- Original Message Follows -----
From: Jeff Shanab <[EMAIL PROTECTED]>
To: Electric Vehicle Discussion List <[email protected]>
Subject: RE: 3kw genset for $315
Date: Thu, 06 Apr 2006 06:48:18 -0700
>Cor van de water said
>snip
>
>>It does not make environmental sense (a genset
>>pollutes at least ten times as bad as a regular
>>car
>snip
As I have stated before, that depends. John's
earlier statements may be true about flat head motors, but
the newer ones with OHV/OHC can do so much better in both
SFC and pollution.
Assuming you want to just increase range, a 9 hp
Robin motor driving a PM or Shunt wound gen/motor will put
out over 5kw/hr which at my 100 wthrs/mile rate gives me 50
mile extra mile each hr. For you just do the math from
there. I'd bet it will give you the range you need easily.
For me it means unlimited range with my 100 mile batt range.
With a A-89 motor with shunt fields, it weighs about 100 lbs
so you may be able to just put it on your rear bumper
instead of dealing with a trailer.
Why I suggest the Robin is it is a low pollution,
high performance engine that's light and used in my EV, puts
out less than a Gram/mile combined HC/NOx emissions. Honda's
OHV's does about 25% more pollution. Subaru/Robin does it
with ign advance, 9-1 compression, OHC with a pent roof
combustion chamber which lowers it's emissions nicely. While
a <G/mile is a little more than the best cars, it's not bad
considering how short a time it will be needed.
>
>
>Does that have to be that way? I want to make a gentrailer
>to extend my range for those out of town trips. I was
>thinking of either a 400hz aircraft generator or a PM
>generator for the DC end direct to the pack since every
>conversion costs and generatig power is already one
>conversion. (Although, I have an idea about that)
Most Aircraft gens are rather poor eff. A PM or shunt
wound is your best bet. Most common EV motors come in shunt
fields too.
>
>What kind of motor can I get to run this effiently, can it
>run on the propane tanks that can be found at orchard
>supply and RV places? sterling? turbine, piston, rotory,
>atkinson? I mean, what is avail in low emmision small
>motors? How about a newer, smog equiped motorcycle or a
>little 3cyl geo motor.
If you want unlimited range it's very hard to beat the
3 cyl geo motor as it only weighs 100lbs in aircraft trim
and plenty of aftermarket parts for them from aircraft
people. Since you don't need that 56 hp, you should run it
at about 2200rpm and say 20 hp putting out about 12 kw very
eff. Almost any other motor will not be as good eff, weight,
pollution wise in it's size range. As long as it is putting
out close to it's rated power at the RPM, it's in it's eff
sweet spot. Thus why you should keep it's rpm low since you
don't need that much power.
If you want to use propane, NG or ethanol, you need to
raise the compression ratio and advance the timing and even
run it hotter to get the best eff, lowest pollution. I'd use
gas or gasohol myself as that's what it's designed for.
>
>My biggest problem is the drive I want is 100 miles ending
>in a 2000-3000 foot climb, that is some serious amps.
>
>
>The Idea : since most internal combustion engines are only
>25% effient, the other 75% is given off in heat. That means
>there is more energy available from the exhaust heat than
>is avil from the shaft. Maybe we can come up with an
>inexpensive method($,weight,space) to convert this heat to
>power, perhaps a thermocouple battery, Peltiers are so
>expensive but they would be a heck of a way to charge the
>added batteries in a hybrid :-)
There isn't any good choices right now but as the
price of gas, diesel goes up, you'll se first in semi's,
steam of other rankine motors running off the radiator,
exhaust heat to increase overall eff probably 20% more to
50-60% at wide open throttle.
Jerry Dycus
>
>
--- End Message ---
--- Begin Message ---
Ryan Bohm wrote:
>
> Evan,
>
> >I think Lee is proposing that you could use the traction controller to
> >power only the field (use a SPCO contactor to switch the armature out)
> >and in the simplest form you'd just press the accellerator to get
> >regen, with the "regen" switch thrown.
> >
> >
> Did you mean push the brakes to get regen? Pushing the amp-pedal to get
> regen sounds like a fun experience :)
The pot on the controller is what controls regen in this setup. But I
agree; you'd be better off mounting a second pot on the brake pedal, and
wiring things to connect it during regen.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Jeff Shanab wrote:
>
> I like this idea!
>
> To simplify the control, Would there be enough residual magnatizm since
> the field is DC to power the field off of the regen energy?
>
> So when the throttle is lifted the throttle closed switch is used via a
> AC contactor to connect the 3phase sliprings and the recified output is
> tapped with a resistor to give enough field voltage to keep the magnetic
> field going, then when we press on the brakes, the resistor is shorted
> with a lesser value to get more braking. Or would this be too abrupt?
>
> Would the freewheel diodes in the controller mess with this?
Lots of finesse issues. I'm just thinking about the motor itself at this
point.
Clearly, the amount of regen power is roughly equal to the motor power.
If the motor can run at 100v at 100a, it can *generate* 100v at 100a. So
it can easily power its own field. There is probably enough residual
magnetism to get it started, as long as the motor is above some rpm.
--
Ring the bells that still can ring
Forget the perfect offering
There is a crack in everything
That's how the light gets in -- Leonard Cohen
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Hi all,
Some of you may remember when I reported that on my
very first test drive with Nicds, i reversed one
'module' of batteries (20 BB600 cells per 'module')
because i stupidly hadn't charged them the same as the
rest.
Anyway, when i got back to my garage and realized what
I had done, I tried to hook up my little lab power
supply to drive the module back to positive, but is
instantly smoked (i guess it wasn't reverse polarity
protected).
so, now I am trying to figure out what smoked. Can you
help ? I am mostly a chemical/mechanical type, but I
understand electronics and can work a multimeter or
scope. And I am interested to learn.
The power supply is a basic bench top 0-30 V, 3A
supply. It is one of those 'sort of' standard
transformer based lab power supplies (30V, 3A) with
individual voltage a current adjustment knobs. It is
made by Electro Industries and has a part number Digi
35A. But i doubt that matters much, since i am
guessing these types of supplies are all similar. It
seems like there is a transformer, a bunch of control
circuits, some display circuits, a couple solid state
switches (are they fets ?).
Anyway, the symptoms are : the power supply still
turns on, but the display comes up and i can turn the
current up and down, but the voltage stays at .2 V no
matter what. any ideas about how to fix this ?
when the supply fried, i saw just a tiny wisp of smoke
come out of the supply. It seemed like it came from an
area in the case where there are not a lot of
components, so I thought I would start there to see if
I could find a bad part. There are two main parts in
that area. One is a capacitor (labeled 63 V, 3300uF),
the other is a solid state switch (fet?) that is about
1/2 in squared and is heat sinked to the base of the
supply. Neither looks obviously burned.
so my question, how can i test those individual
devices ? Is there something I can do with a
multimeter to see if the Cap is ok ? My DMM has a
setting for CAP, but i have never used it. what is the
failure mode for a cap anyway ? shorted ? loss of
capacitance ?
what about the 'switch' ? It has four leads coming off
it and two of them appear to be tied to together by a
resistor (R-Y-Br-R; is that 240 ohm?). Should I assume
those two are the 'coil' and the others are the
contacts ?
anyway to check to operation of this device ?
Finally, at the back of the supply there are two
circular discs mounted on a big heat sink. They look
like thermal snap discs or something, and have part
number " Greaves Limited 2N3055HV" printed on them ?
What is the function of these ? They both read 'open'
between the pins, which seems odd if they are over
temperature protection (since it is about 40 degrees
in my garage today).
anyway, i realize this is a touch OT, but this supply
is my EV battery comissioning supply, and i know there
are electronics experts on this list and I hope one of
you is patient enough to help me learn some of this
stuff.
i am most grateful for your help.
~fortunat
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--- Begin Message ---
This was a 156vdc system like I recommended but 500 pounds can be lost by
using a truly minitruck. An older toyota, Datsun or Mazda long bed will
have less weight & carry just as much in gross vehicle weight. With A zilla
controller you will have a very nice ride indeed. Lawrence Rhodes..
----- Original Message -----
From: "bruce parmenter" <[EMAIL PROTECTED]>
To: "evlist" <[email protected]>
Sent: Friday, April 07, 2006 4:51 PM
Subject: Re: best donor car for 2000lb of lead
Also take a look at
http://www.jacksonemc.com/news/news_stories/firefly.html
80 mile range, charges overnight
-
The Fire Fly is a 1983 Ford Ranger pickup truck, which was
transformed into an electric vehicle. Weighing nearly two and
one-quarter tons, the Fire Fly runs on 6-volt batters, 26 of them,
with a 12-volt auxiliary batter that provides power to control the
circuits of the EV electronics as well as the auxiliary equipment
like lights and instruments. The car will travel 80 miles on charge
and takes six to eight hours to recharge. "At typical residential
electric rates of $.065/kWh, the truck can recharge for less than
$2, and you can't go very far on $2 worth of gas these days," says
Shedd.
-
Bruce {EVangel} Parmenter
' ____
~/__|o\__
'@----- @'---(=
. http://geocities.com/brucedp/
. EV List Editor, RE & AFV newswires
. (originator of the above ASCII art)
===== Undo Petroleum Everywhere
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--- Begin Message ---
Hello to All,
I always enjoy the AC vs DC debate. One point very rarely brought up
though, is what you get in terms of performance in return for your
dollars invested, especially when the price of the AC system hovers in
the $8000-$10,000 range. Yes, a 68 kw AC system can be had for about
$6000, but that's on the low side of power for a conversion and is more
comparable in power to older tech 120V DC systems. To get up to the
power level of today's common 144V-156V DC systems being used that
easily top 100 kw, the AC system will cost you closer to $8000. For
$8000-$10,000, you get an AC system with about 100-130 kw of power. For
the same dollars for DC....listen up newbies and pro AC folks, you get
up to 600 kw!!!! I'm talking about raw power that can be easily had with
a Zilla Z2K, stout AGM batteries, and either one BIG DC motor or a pair
of DC motors. Now, in real life, due to the fact that batteries sag
under high current loads, no one that I know presently has actually
gotten their 600 kw of power delivered in their EV, but I do know that
350 kw has been had :-) We're talking about THREE times the power for
the same price...I'll repeat....THREE times the power for the same
price! Not just two times the power, THREE times the power!
From Metric Mind's web page, specialists on AC systems (good folks to
do business with) comes this statement:
>Zilla 2K comes to mind....with a DC motor becomes $6100, just $800
less than a complete AC solution (100 kw).
It goes on to admit that even the Z1K at half the power of the Z2K still
has more power than this AC system, but the power level thing is
down-played. The problem I have is where the Z2K, a 600 kw system is
compared to the 100 kw AC system, where this part is left out.....The
Z2K Zilla package delivers SIX times the power for the same price (if a
powerful enough battery pack is used) and in practical terms, it
delivers THREE times the power!
A nice 100-130 kw AC system 'can' match the power delivery of the
average gas car, but so can an affordable 100-130 kw DC system.
The big difference in this power range, is that a simple pack of just 13
AGM 12V batteries (156V) and a Zilla Z1K will easily make 130 kw of
delivered power. Here's the approximate cost to do this....$2000 for the
Z1K LV model, $1450 for 13 Optimas or Orbitals, and $1600 for a 9 inch
DC motor, for a total 130 kw package of $5050. A 100-130 kw AC system
will cost you about $7000, but to run it to the power level of around
100 kw, you need a 300V battery pack. That pack will cost twice as much
as the 156V pack for the DC system, even if you run smaller AGM
batteries so that the overall pack weight is the same (same approx.
range) as the 13-battery DC pack. So, for $7000 for the inverter-motor
combo and $2800 of batteries you are up to $9800! We're looking at twice
the cost for the same level of performance. When using battery
management modules, the cost of these is doubled with the 300+V AC
system, too.
Am I dissing AC? Of course not. I love AC. My Insight has it, many of
the forklifts I work on have it, and one of my favorite EVs I've driven,
the EV1 had it. From time to time, I think about converting Blue Meanie
to a 130 kw AC system. After all, I already have a really fast DC Datsun
1200, why not have a little regen fun and do the other 1200 as an AC
system? The only problem I have is price for what you get in return.
With similar weight lead acid battery packs, I'll pit my DC powered car
to 'any' AC powered car in terms of range per charge, 0-60 acceleration,
top speed, and over-all fun factor. On the other hand, a direct drive AC
Blue Meanie with a higher tech battery pack is a fun concept.
From time to time, I get to hang out with Victor (Metric Mind). A few
weeks ago, he and I got together at his place. I found myself smiling at
his latest AC system with a very compact inverter module and a motor
that was, well, more 'motor-like' than some of his other square AC
motors. It screamed 'Blue Meanie' at me. I also nearly tripped over
stacks of Ovonic NiMH batteries, the same models that were used in the
EV1 I drove for 140 miles per charge years ago! I was thinking a set of
them and that nifty compact AC system would turn Blue Meanie into a 150
mile per charge machine, while still maintaining 'respectable'
performance. Alas.....it would cost about $10,000 to get these toys.
For now, I'll be putting a pack of Hawkers into Blue Meanie to get it
back to snuff (the 6.5 year old Optimas are finally ready to be
recycled). Until I take the AC plunge, I guess I'll have to settle for
0-60 in six seconds, a 120+ mph top speed, and the 'city driving only'
range of 25 miles per charge (unless I get some really new model Hawkers
I'm not supposed to talk about yet).
Kudos to Victor for helping to make AC systems available to backyard
converters. It's great to have these systems available at more
reasonable prices than the $20-$30k systems of the late 90's!
See Ya.....John Wayland
--- End Message ---
--- Begin Message ---
http://jobsearch.monster.com/getjob.asp?JobID=39818055&AVSDM=2006%2D02%2D16+
16%3A52%3A36&Logo=1&co=xw53699653wx&ah=http://company.monster.com/w53699653w
&aj=ISE+Corporation
(Posted in February with "need to start in 4 weeks", but position is still
open)
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
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--- Begin Message ---
On Apr 8, 2006, at 7:57 AM, Ryan Bohm wrote:
Thanks Doug for the quick links. Slip rings just look like a
commutator/brush assembly. Correct?
-Ryan
Exactly the same, only different :)
The brushes are pretty much the same. However, in a commutator/brush
assembly, there are a series of different conductors (commutator bars)
passing underneath the brush. In a slip ring/brush assembly, it's all
the same conductor (the slip ring) passing under the brush. Less
complicated.
There's still the same problem of insulating the slip ring from the
motor shaft.
Here's an idea. Take a standard ADC commutator assembly. Braze the
slots closed, forming one big conductor. Turn it down to smooth it.
Voila, one slip ring, already sized to fit onto the motor shaft.
Another advantage of using a standard comm is that a standard brush
assembly will work with it, too. Of course they're big, so fitting
three of them on an ADC motor will require a custom end bell, or three
end bells all stacked together. The flip side of "big" is that it also
means "high power", which is a good thing.
That should be enough to get Jim started :)
--
Doug Weathers
Bend, OR, USA
<http://learn-something.blogsite.org/>
--- End Message ---
--- Begin Message ---
On Apr 8, 2006, at 9:37 AM, Tom Watson wrote:
"why couldn't you build a non-identical twin, motor/generator set-up
for regen..."
You can certainly do that. Reverend Gadget's conversion comes to mind.
Check out the last picture on the page.
<http://www.reverendgadget.com/triumph2.html>
--
Doug Weathers
Bend, OR, USA
<http://learn-something.blogsite.org/>
--- End Message ---
--- Begin Message ---
These are exactly the thoughts that run through my mind when looking at the
AC systems. The current ones I see don't have enough power for the buck.
80HP is just a bit low.
----- Original Message -----
From: "John Wayland" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, April 08, 2006 1:56 PM
Subject: AC vs DC
Hello to All,
I always enjoy the AC vs DC debate. One point very rarely brought up
though, is what you get in terms of performance in return for your dollars
invested, especially when the price of the AC system hovers in the
$8000-$10,000 range. Yes, a 68 kw AC system can be had for about $6000,
but that's on the low side of power for a conversion and is more
comparable in power to older tech 120V DC systems. To get up to the power
level of today's common 144V-156V DC systems being used that easily top
100 kw, the AC system will cost you closer to $8000. For $8000-$10,000,
you get an AC system with about 100-130 kw of power. For the same dollars
for DC....listen up newbies and pro AC folks, you get up to 600 kw!!!!
I'm talking about raw power that can be easily had with a Zilla Z2K, stout
AGM batteries, and either one BIG DC motor or a pair of DC motors. Now,
in real life, due to the fact that batteries sag under high current loads,
no one that I know presently has actually gotten their 600 kw of power
delivered in their EV, but I do know that 350 kw has been had :-) We're
talking about THREE times the power for the same price...I'll
repeat....THREE times the power for the same price! Not just two times the
power, THREE times the power!
From Metric Mind's web page, specialists on AC systems (good folks to do
business with) comes this statement:
>Zilla 2K comes to mind....with a DC motor becomes $6100, just $800
less than a complete AC solution (100 kw).
It goes on to admit that even the Z1K at half the power of the Z2K still
has more power than this AC system, but the power level thing is
down-played. The problem I have is where the Z2K, a 600 kw system is
compared to the 100 kw AC system, where this part is left out.....The Z2K
Zilla package delivers SIX times the power for the same price (if a
powerful enough battery pack is used) and in practical terms, it delivers
THREE times the power!
A nice 100-130 kw AC system 'can' match the power delivery of the average
gas car, but so can an affordable 100-130 kw DC system.
The big difference in this power range, is that a simple pack of just 13
AGM 12V batteries (156V) and a Zilla Z1K will easily make 130 kw of
delivered power. Here's the approximate cost to do this....$2000 for the
Z1K LV model, $1450 for 13 Optimas or Orbitals, and $1600 for a 9 inch DC
motor, for a total 130 kw package of $5050. A 100-130 kw AC system will
cost you about $7000, but to run it to the power level of around 100 kw,
you need a 300V battery pack. That pack will cost twice as much as the
156V pack for the DC system, even if you run smaller AGM batteries so that
the overall pack weight is the same (same approx. range) as the 13-battery
DC pack. So, for $7000 for the inverter-motor combo and $2800 of batteries
you are up to $9800! We're looking at twice the cost for the same level of
performance. When using battery management modules, the cost of these is
doubled with the 300+V AC system, too.
Am I dissing AC? Of course not. I love AC. My Insight has it, many of the
forklifts I work on have it, and one of my favorite EVs I've driven, the
EV1 had it. From time to time, I think about converting Blue Meanie to a
130 kw AC system. After all, I already have a really fast DC Datsun 1200,
why not have a little regen fun and do the other 1200 as an AC system? The
only problem I have is price for what you get in return. With similar
weight lead acid battery packs, I'll pit my DC powered car to 'any' AC
powered car in terms of range per charge, 0-60 acceleration, top speed,
and over-all fun factor. On the other hand, a direct drive AC Blue Meanie
with a higher tech battery pack is a fun concept.
From time to time, I get to hang out with Victor (Metric Mind). A few
weeks ago, he and I got together at his place. I found myself smiling at
his latest AC system with a very compact inverter module and a motor that
was, well, more 'motor-like' than some of his other square AC motors. It
screamed 'Blue Meanie' at me. I also nearly tripped over stacks of Ovonic
NiMH batteries, the same models that were used in the EV1 I drove for 140
miles per charge years ago! I was thinking a set of them and that nifty
compact AC system would turn Blue Meanie into a 150 mile per charge
machine, while still maintaining 'respectable' performance. Alas.....it
would cost about $10,000 to get these toys.
For now, I'll be putting a pack of Hawkers into Blue Meanie to get it back
to snuff (the 6.5 year old Optimas are finally ready to be recycled).
Until I take the AC plunge, I guess I'll have to settle for 0-60 in six
seconds, a 120+ mph top speed, and the 'city driving only' range of 25
miles per charge (unless I get some really new model Hawkers I'm not
supposed to talk about yet).
Kudos to Victor for helping to make AC systems available to backyard
converters. It's great to have these systems available at more reasonable
prices than the $20-$30k systems of the late 90's!
See Ya.....John Wayland
--- End Message ---
--- Begin Message ---
From: "Robert Chew" <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: RE: Low efficiency with light loads
Date: Wed, 05 Apr 2006 18:24:44 +1000
I wonder what could have happened? I hate taking measurements. too tedious.
Hi Robert,
If I followed this thread correctly, you are taking measurements for a
thesis, which suggests to me you are an engineering student. The fact that
you hate taking measurements because it is "too tedious" suggests too me
that you are not cut out for true engineering. I don't mean that in a
negative way, I am in the same boat as you. Just be careful not to head
down a career path that you can never truly be happy in or excel at because
it does not fit who you are. I have worked around people who are true
engineers and I can tell you they can't stand to NOT take tedious
measurements. It drives them nuts. I started out wanting to be an
Electrical Engineer, but discovered that engineering really wasn't for me.
I'm very happy in my current career, but I am always amazed when people try
to shoehorn themselves into something that really does not work for them.
Not only do they not enjoy their work, but they are not very good at it.
damon
--- End Message ---
--- Begin Message ---
2N3055 are NPN power transistor i suppose HV is for high voltage type.
They are the power stage of your supply, and they have to be open when not
powered by their base pin
This page will tell you all about them and also testing:
http://www.kpsec.freeuk.com/components/tran.htm
Such PS should be short-circuit/reversal protected but not for too much time
or too much current so probably this protection was killed or defeated in
the process.
http://shop.store.yahoo.com/webtronics/digi-35a.html
cordialement,
Philippe
Et si le pot d'échappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
Forum de discussion sur les véhicules électriques
http://vehiculeselectriques.free.fr/Forum/index.php
----- Original Message -----
From: "Fortunat Mueller" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, April 08, 2006 7:22 PM
Subject: adventures in electronics
> Hi all,
>
> Some of you may remember when I reported that on my
> very first test drive with Nicds, i reversed one
> 'module' of batteries (20 BB600 cells per 'module')
> because i stupidly hadn't charged them the same as the
> rest.
> Anyway, when i got back to my garage and realized what
> I had done, I tried to hook up my little lab power
> supply to drive the module back to positive, but is
> instantly smoked (i guess it wasn't reverse polarity
> protected).
>
> so, now I am trying to figure out what smoked. Can you
> help ? I am mostly a chemical/mechanical type, but I
> understand electronics and can work a multimeter or
> scope. And I am interested to learn.
>
> The power supply is a basic bench top 0-30 V, 3A
> supply. It is one of those 'sort of' standard
> transformer based lab power supplies (30V, 3A) with
> individual voltage a current adjustment knobs. It is
> made by Electro Industries and has a part number Digi
> 35A. But i doubt that matters much, since i am
> guessing these types of supplies are all similar. It
> seems like there is a transformer, a bunch of control
> circuits, some display circuits, a couple solid state
> switches (are they fets ?).
>
> Anyway, the symptoms are : the power supply still
> turns on, but the display comes up and i can turn the
> current up and down, but the voltage stays at .2 V no
> matter what. any ideas about how to fix this ?
>
> when the supply fried, i saw just a tiny wisp of smoke
> come out of the supply. It seemed like it came from an
> area in the case where there are not a lot of
> components, so I thought I would start there to see if
> I could find a bad part. There are two main parts in
> that area. One is a capacitor (labeled 63 V, 3300uF),
> the other is a solid state switch (fet?) that is about
> 1/2 in squared and is heat sinked to the base of the
> supply. Neither looks obviously burned.
>
> so my question, how can i test those individual
> devices ? Is there something I can do with a
> multimeter to see if the Cap is ok ? My DMM has a
> setting for CAP, but i have never used it. what is the
> failure mode for a cap anyway ? shorted ? loss of
> capacitance ?
>
> what about the 'switch' ? It has four leads coming off
> it and two of them appear to be tied to together by a
> resistor (R-Y-Br-R; is that 240 ohm?). Should I assume
> those two are the 'coil' and the others are the
> contacts ?
> anyway to check to operation of this device ?
>
> Finally, at the back of the supply there are two
> circular discs mounted on a big heat sink. They look
> like thermal snap discs or something, and have part
> number " Greaves Limited 2N3055HV" printed on them ?
> What is the function of these ? They both read 'open'
> between the pins, which seems odd if they are over
> temperature protection (since it is about 40 degrees
> in my garage today).
>
> anyway, i realize this is a touch OT, but this supply
> is my EV battery comissioning supply, and i know there
> are electronics experts on this list and I hope one of
> you is patient enough to help me learn some of this
> stuff.
>
> i am most grateful for your help.
>
> ~fortunat
>
>
>
>
> __________________________________________________
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> http://mail.yahoo.com
>
--- End Message ---
