EV Digest 5928
Topics covered in this issue include:
1) Re: AC vs DC?
by Lee Hart <[EMAIL PROTECTED]>
2) Re: AC vs DC?
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Charging Woes
by Lee Hart <[EMAIL PROTECTED]>
4) Re: bad boy charger questions
by Lee Hart <[EMAIL PROTECTED]>
5) Re: Short and blunt
by <[EMAIL PROTECTED]>
6) Books or References on AC Motors and Controllers
by "Don Cameron" <[EMAIL PROTECTED]>
7) Re: Did someone say cheap EV!! Re: Cheapest not most efficient ev
by "Phil Marino" <[EMAIL PROTECTED]>
8) Re: AC vs DC?
by Jeff Major <[EMAIL PROTECTED]>
9) Re: bad boy charger questions
by [EMAIL PROTECTED]
10) Re: Short and blunt
by [EMAIL PROTECTED]
11) FAST EV - OT
by "Harry Houck" <[EMAIL PROTECTED]>
12) RE: AC vs DC?
by "Michael Trefry" <[EMAIL PROTECTED]>
13) Re: Join In! WAS : AC vs DC?
by "Bob Rice" <[EMAIL PROTECTED]>
14) Voltage rating on Heinemann GJ1P series
by Ray Wong <[EMAIL PROTECTED]>
15) Re: Books or References on AC Motors and Controllers
by <[EMAIL PROTECTED]>
16) Re: Parts worth salvaging?
by "Bob Rice" <[EMAIL PROTECTED]>
17) RE: FAST EV - OT
by Cor van de Water <[EMAIL PROTECTED]>
18) Re: Voltage rating on Heinemann GJ1P series
by Eric Poulsen <[EMAIL PROTECTED]>
19) RE: AC vs DC?
by "Andrew Roberts" <[EMAIL PROTECTED]>
20) Re: GPS as speed and distance log. 0 to 60 time measurement
by Eric Poulsen <[EMAIL PROTECTED]>
21) Re: Charging Woes
by "steve clunn" <[EMAIL PROTECTED]>
--- Begin Message ---
Michael Trefry wrote:
Please excuse my ignorance, I'm just trying to understand.
How can DC be the same thing as AC?
If I'm not mistaken, DC is direct current, meaning a steady stream of
electrons going in a single direction, while AC is alternating meaning that
it's constantly going back and forth. Right?
There is no +/- with AC right?
All motors are AC. There has to be AC in the coils, or the motor is very
inefficient and awkward. What you think of as a DC motor is really an AC
motor with a mechanical inverter (the commutator and brushes) that
converts the incoming DC power into AC.
Surprising, but true!
--
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 ---
Death to All Spammers wrote:
So, how often has a production DC vehicle (tug, forklift, whatever,
doesn't have to be street-legal) had a runaway situation (i.e.
something like MTBF)?
They're rare... but they've happened. The post mortem usually reveals
that somebody got careless and left out an interlock system, or used a
substandard part that couldn't shut off when the need arose. These are
most likely to happen with hobbyist built systems.
--
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 ---
TiM M wrote:
OK, I have a 144V pack of US 145s that is about a year
old. I’ve been using the 2.583V per cell number
provided by US battery at 80C to get a finish voltage
of 186V... The charger never shut off, it ran all night
at 10 amps... I ended up having to lower the voltage
set point to 173 or so volts and stops... I checked the
voltage right after an 8 mile run, all the batteries
read 6.3V +/- .03. Any guesses?
2.583v/cell is the ending voltage for a NEW battery, at normal
temperature, and at a charging current of 2% of the battery's amphour
capacity (about 5 amps for a T-145), for a limited time (no more than
1-2 hours. So, there are several possibilities:
- The batteries might be hot.
- The batteries might be getting old.
- You might have one or more bad cells.
Have you measured the normal current at the end of a charge cycle at
that 2.583v/cell? The PFC charger you're using can deliver max current
at max voltage; it's not limited to 5 amps or some safe level. So, any
of the above factors could be causing your end-of-charge current to be
high. If this has been going on a long time, the pack could have been
chronically overcharged; this could result in the whole pack going bad
before its time.
How many charge cycles have you applied like this? How long does each
one last? It may be that the batteries have been sitting at this high
voltage for much longer than needed, giving the pack a full hard
equalization on every cycle.
--
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 ---
mike golub wrote:
I was desperate so I used a bridge to charge my batteries.
It seems to be working fine.
I’m not using any capacitors or coils.
Am I missing something?
No. A "bad boy" charger works fine, as long as everything goes well and
you manually monitor what it is doing. I've used them myself for years.
But a "bad boy" will get you in trouble if you forget to watch it, or if
something goes wrong that is not according to plan. It can *destroy*
things! Your batteries, wiring, connectors... or even start a fire. They
are also a shock hazard, and can electrocute someone.
That's why it makes sense to tame them with a few simple additions. Here
is a *minimal* list of what I think you need.
- an input fuse or circuit breaker
(to protect your house wiring)
- a DC-RATED output fuse or circuit breaker
(in case the bridge rectifier fails)
- a mechanical timer
(to turn it off in case you forget)
- a GFCI
(to shut it off and avoid a shock hazard)
- an ammeter and voltmeter
(so you know what it's doing to your batteries)
- a thermal cutout switch on the bridge rectifier
(to turn it off if it overheats)
- a fan to keep it cool
(if you try to pack everything in a small, tight box)
- some kind of switchable current limiter
(to avoid excessive current if pack is deeply discharged)
The last item can be accomplished many ways. The cheapest/worst is a
long extension cord, to act as a resistor. But don't coil it up; it will
overheat and melt!
I prefer an inductor. They are more efficient (don't get nearly as hot),
and filter the current peaks so you can get more charging amps from a
given AC outlet. You can buy one (Jameco #618329CM $38.95, 10mH, 12.5a)
or make your own out of an old transformer. Remove the windings from a
roughly 5 lbs transformer, and replace them with as many turns of #14 or
#12 wire as will fit. Stack up all the "E" laminations on one side, and
all the "I"s on another. Put paper shims between the E's and I's to get
whatever inductance (and max charging current) you want. Or, provide a
couple taps that you can switch to get low/medium/high charging currents.
You can also use series capacitors; this works better if there is a
large voltage difference between your pack and the AC line (like
charging a 120v pack from the 240vac line). These *must* be AC rated
"motor run" type capacitors, not electrolytics!
--
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 ---
WOW Go get em Rich!
This is a tech forum so it would be great to stick to that instead of the
personal attacks. On another NG there's this cliff person who has been
killfiled by practically everyone because he's a PITA even if he has real
info to comment on. I hope everyone will realize we all have the freedom to
critique and suggest and that includes the freedom to politely disagree with
any and everything we don't subscribe to. That said I utter the infamous
"Can't we just get along?".
Keep up the hard work on our core focus. EV
Pedroman
----- Original Message -----
From: "Rich Rudman" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, September 27, 2006 12:36 PM
Subject: Re: Short and blunt
Your arrogance Befuddles our Brilliance..
It certainly was not your technical Bandwidth that Offended me..
It clearly is your attitude.
This is a technical list not a Old English literature list.
Voltaire would understand.. it's not the freedoms that I wish to limit
it's
your heavy handedness and lack of regard for those of us who DO.
Do meaning.. Do stuff for a living instead of talk about it.
Dissent?? More Like BS detector.
I am proud of that, and the list, in general, is happy to have me lay down
some heavier handedness when required.
By the way this is the second direct personal attack on this list.. for no
real good reasons.
How many do you think you are going to get away with??
You certainly are not taking the behavior hints very well.
So..Shall we get back to EV issues..
Or will I endure a Spelling and Grammar check???
OK just for you, I will run the spelling checker...
ya Know .. I don't know what my true status on Mg was, Besides Jesse's and
the Camera crews whipping boy, But the check stub said Build team
leader...
So.. I kinda have stuck with that.
Read into it what you will...
Enough of this Fluffy waste of Bits,
lets get back to EV stuff.
Madman
----- Original Message -----
From: "David Ankers" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, September 25, 2006 12:20 PM
Subject: RE: Short and blunt
Hi "Build leader"
Friendly place this. Especially when the matter had been put to bed, yet
your little man syndrome kicked it. Seems anyone that dissents and dares
to
question anything on this list is open to attack. Poor Jack just got a
dose
for daring to point out some new NiMH cells.
I don't agree with some things you say and find you abrasive and uncouth
YET, the key difference between us is that I would never ask for anyone
to
be removed from this list. In the words of Voltaire "I might not agree
with
all you say but I will defend your right to say it". You however, want
anyone that appears to disrespect your imaginary hierarchy to be removed.
Unlike you, I do not wish to get respect (you're projecting) however, I
do
wish to know the truth.
I might have appeared to come from nowhere but I've been here a while and
as
you can tell, I've seen you pull these outbursts before, "build leader".
Let's be clear: the point of your post was to stamp your authority and
reinforce the hieratical structure you have built in your head of the EV
world, with you somewhere near the top.
Cliff's mails did bother me; I tried to debate the issue yet he turned
nasty, however, you don't really bother me at all and I have even less
respect for you now for trying to jump on someone you thought was new to
EVs
and attempt to scare them away from what you appear to consider your
list.
P.s. Seam is a noun, as in a line of stitching, I think you wanted the
word
"seem" which is a verb. As in: "I seem to be a verb" :-)
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Rich Rudman
Sent: Tuesday, 26 September 2006 1:56 AM
To: [email protected]
Subject: Re: Short and blunt
Oh It looks like we have a short timer...... abusing a long time Ev
lister....
First David... treading ligher might give you a little better respect
here
on this list.
Cliff has been on this list for a long time sharing his experiences with
Kokam's.. this is very usefull information.
You Seam to have come out of no where and know more than Guy who has
years
of abusive racing on Said Batteries.
Guess who we are going to lilsten to???
Clearly not the Sqeaky voiced Punk that has some nasty things to say
about
some pretty good batteries.
So I cast my vote to the list Gods to send you on your way.
If you have something to say, Say it cleanly and clearly and back it up
with data.. or don't say it all.
have a nice Day..
On some other list please.
Madman
----- Original Message -----
From: "David Ankers" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, September 25, 2006 7:45 AM
Subject: RE: EVLN(Lithium-ion battery fires concern auto
enthusiasts)-Long
> I'm sorry you chose to run away from the debate especially without
> addressing any of the issues but instead did the equivalent of sticking
your
> fingers in your ears and singing "I'm can't hear you", is this a mature
> response?
>
> Now, for the record and for the list - as you're not listening ;-), I
posted
> what are called OPINIONS, sorry that you don't like them but I have
> that
> right. You responded to my own personal OPINIONS with a highly
inflammatory
> mail (which you stated yourself) and raised tired old fallacies. You
acted
> like a dick and I called you on it, your first reply to my OPINIONS was
an
> inelegant attempt at a put down and if you were honest with yourself
> you
> would admit that, although by running away you obviously know you are
not
on
> a sure footing.
>
> You might not know Kokam have had problems with the large packs, and
> something else you don't know: my brother was the sole importer for
Kokams
> in the UK for over a year and they had scaling problems then.
>
> I'm above your ad hominem attacks so let's clarify some real points:
>
> My comment about Kokam claiming 500 cycles: I refer to the fact that
they
> make this claim when it is false, has been proven false by independent
> testers and that is with smaller packs. 800 cycles? BWWaaahhh, sure,
> and
I
> also have a rather nice bridge for sale. With batteries, all
manufactures
> make claims, many outrageous and Kokam have a record of this, they were
the
> first manufacture to start using capacity rating with a discharge
current
of
> 0.2c while most other manufactures at the time used 1C, sneaky. Who
> initially denied LiPo cells had a shelf life? Why, that would be Kokam.
>
> I believe there is always things to learn from everybody and have found
this
> to be the case throughout my life, in fact everyone I've met I have
learnt
> something from, or at least I can not thing of anyone I have not learnt
> anything from. Take Cor's excellent response, he quoted verifiable
> facts
and
> simply put the thread to rest, of course, until you had your tantrum.
>
> One thing I find absolutely stunning is your attempt to have the last
word,
> simply amazing. Anyone with a rational mind knows exactly what you are
up
> to; you see, rational people that truly believe that "life's too short"
> would simply deleted the mail and block the sender. You on the other
hand
> waste your "too short life" sending a response! Unbelievable. Further,
I've
> seen you pull the exact same stunt with others on this list and had 2
> private emails after your first outburst stating that you are "arrogant
> without any cause to be" and "not just a dick, an elitist dick" so it
> appears you have upset others as well.
>
> Your behaviour is transparent and from it, I can be certain you will
read
> this mail; ironically though you have prevented yourself from even
replying,
> oh my.
>
> Cliff, be especially careful when talking about items you have a vested
> interest in, such as being sponsored - firstly you must be aware that
you
> can easily come across as a bought and paid for shill out to mislead
> and
> suppress other peoples OPINIONS that don't match what you are trying to
> promote. Secondly, what you do on this public list also reflects on the
> company that sponsors you. Now, go and think about how badly you have
> handled this, in front of a lot of the EV community and how that
reflects
on
> Kokam and their choice to be represented by you. You can't learn
anything
> from me? You just did ;-)
>
>
>
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of ProEV
> Sent: Monday, 25 September 2006 10:32 PM
> To: [email protected]
> Subject: Re: EVLN(Lithium-ion battery fires concern auto
enthusiasts)-Long
>
> David,
>
> I am on the EV list to learn from other's experiences and knowledge and
to
> share my experience and knowledge. It is often a fun and educational
> experience.
>
> But I do not enjoy being called 'a dick'. Life is too short. It is also
> against the list charter
>
> Luckily there is a quick technological fix. I just added your name to
> my
> blocked list.
>
> I often hesitate to do this because there are some abrasive
personalities
on
> the list who do contribute excellent information. Blocking them cuts me
off
> from things I would like to learn.
>
> In your case, I feel there is little danger of that. Statements like <
This
> has been debunked as a false analogy a long time ago.> does not tell me
> anything except that you were convinced by someone's argument. It does
not
> help me learn anything.
>
> You pose vague argumentative statements, < Kokam still have the same
> problems with larger packs failing? > which seem designed to put Kokam
in
> the position of "When did they stop beating their wives". For the
record,
I
> have not heard anything about any Kokam packs failing despite
> exchanging
> information with a lot of Kokam users. ProEV posts our experiences in
public
> to help others learn from our mistakes. We have had cells fail because
we
> have chosen to run the cells outside of what is recommended.
>
> Specifically our 70 amp-hr cells were rate for 5 C (350 amps)
continuously
> but on the track, we would run them closer to their peak rating (700
amps).
> Kokam had no experience under these conditions but suggested that if we
kept
> the cell below 60 degree Celsius, we might just lose some cycle life.
Our
> cooling scheme was inadequate and many cells went over 70 degree
Celsius.
We
> have learned that Kokam is right. High heat can kill a cell.
>
> We have also shorted cells and killed cells by over-discharging them
> but
not
> on purpose.
>
> Other of your statements are just poorly written and hard to understand
> <Kokam claims a lot and always has, they still 500 cycles pack life! >
> .
I
> think you mean that the latest Kokam cells last for only 500 cycles .
This
> would be wrong. The new cells ( called High Power and Ultra High
> Power )
are
> conservatively rated for over 800 cycles.
>
> http://www.kokam.com/english/product/kokam_Lipo_01.html has a graph of
the
> 100% discharge test at over 1,400 cycles. (Everyone should keep in mind
that
> no manufacture has given us a solid answer of calendar life since each
new
> cell formulation has not been around long enough for anything but
simulated
> calendar life testing, so cycle life might not be our biggest concern.)
>
> Good bye, David.
>
> If anyone else has questions about David's arguments that I did not
address,
> please feel free to ask them.
>
> Cliff
> www.ProEV.com
>
--- End Message ---
--- Begin Message ---
Can anyone recommend books or websites on an introduction to AC motors and
controllers. I am technically capable so no problem with basic electronics,
microcontrollers and mathematics.
thanks
Don
--- End Message ---
--- Begin Message ---
Interesting idea, and it sure works for lawn mowers and tanks.
But, it seems to me you might run into problems in an on-the-road vehicle.
For instance, if you were braking and one front wheel momentarily lost
traction and slid, the car (or trike) could just spin around, Normally, the
rear wheels would prevent that, but a single "castered" rear wheel would
not. The same thing would happen if one front wheel spun during
acceleration.
Phil
From: Dave Cover <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: Did someone say cheap EV!! Re: Cheapest not most efficient ev
Date: Wed, 27 Sep 2006 09:55:23 -0700 (PDT)
--- jerryd <[EMAIL PROTECTED]> wrote:
> from something dead like a VW bug one, any series motor of 3
> hp or more like 2 from golfcarts or a forklift motor for a
Jerry
I misread you comment, but that got me thinking about another approach to
the NEV 3 wheeler. I
started thinking about 2 wheel motors in the front without any steering
mechanism. Use the two
motors to steer like a Big mowing deck, like Steve C. uses. The downside is
you'd need two motors
and two controllers, but they could be lighter duty. The rear wheel is just
a caster to keep your
butt off the ground. Might not be great on the highway, but would be
excellent for tight parking.
Almost zero turning radius. Or has this already been shown to be a bad
idea?
Dave Cover
_________________________________________________________________
Be seen and heard with Windows Live Messenger and Microsoft LifeCams
http://clk.atdmt.com/MSN/go/msnnkwme0020000001msn/direct/01/?href=http://www.microsoft.com/hardware/digitalcommunication/default.mspx?locale=en-us&source=hmtagline
--- End Message ---
--- Begin Message ---
Hi Jerry and All,
Times, they are a changin'. And time will tell as to the AC vs DC issue. I
am a relative short timer to the list. I suspect this is not the first time
the issue has been addressed here. But I have had a lot of experience with
both DC and AC systems in EVs. Just trying to share some of it.
Bright minds? Successful? My take is YES. Those gold plated EVs may have
been successful had it not been for bad business decisions. But design
success, I say yes. Look at Toyota. Better business decisions, better EV
(HEV) success.
In the mean time, anyone wants to market an EV with DC commutator motor and
golfcar batteries, more power to them. I'm behind it.
Why change? Better functionality, reliability and efficiency. And AC does
not necessarily have to be high voltage. Many fork lifts are offered, DC or
AC, same voltage battery pack. As for the cost issue, it is far more than just
that of the controller. Especially with an EV for the masses. You'll have to
account for validation, tooling, warranty, etc. The big companies see an
advantage for AC here.
The first hand held calculators were much more expensive than slide rules.
And not even as functional. Why change?
Jeff
jerryd <[EMAIL PROTECTED]> wrote:
Hi Jeff and All,
----- Original Message Follows -----
From: Jeff Major
To: [email protected]
Subject: Re: AC vs DC?
Date: Wed, 27 Sep 2006 09:05:23 -0700 (PDT)
>Let's look at the last opinion expressed by Mr. Hart. Why
>would one think that GM, Toyota, Ford, Azure, ISE, etc
>would NOT use experts on EV design for their EV and HEV
>products which use AC motors? I believe these companies
>have some of the brightest minds in the world designing and
>engineering these modern electric drive systems.
Bright minds?? Were they successful? Why?
Because they built expensive, gold plated EV's that
never would be cost effective. No? Also they have little EV
experience!!! We have hundreds of times more on this list!!
Now had they built a real mini pickup as an EV that
didn't weigh so much, more aero so they could use a much
smaller battery pack of golf cart batteries with a DC series
or Sep Ex EV drive, then we would have EV's right now that
would be cost competitive with ICE's.
>
> Also, the vast numbers of commercially successful EVs
>(fork lifts, buses, trains, etc) which are DC owe the vast
>numbers to the fact they have been around for decades, if
>not a centruy.
Yes they are. So why change? A DC motor can be as eff
as any AC one, especially if you need torque which we do.
And a DC controller will be a little more eff and will be
lower cost by at least a factor of 2.
Now please tell me again why AC with it's costly high
voltage battery pack/controllers is a better EV drive?
If one wants to be successful, one uses the proven,
cost effective tech. That's what I'm doing.
The cheapest AC/motor/controller I could find was $4k
while a more powerful DC system cost under $1k.
As a manufacture has to get at least 2x's it's costs
to build, it will cause an EV to be $6k more just for the
privilge to say you use AC. You are not going to be
successful with those thought processes.
Most, if not all, that are currently being
>produced are either looking at AC drives or offering
>vehicles using AC drives. Since the advent of economic and
>reliable power electronic devices and information
>processors, the shift from DC to AC motor systems has been
>noticeable, industry wide.
>
> Don't get me wrong, I love the DC commutator motor. What
>a great machine. I also respect the AC systems a great
>deal.
I don't respect AC motors with the exception of BLDC
PM disc type motors that are eff, easy, low cost to build as
are my version of their controllers. But until I can build
mine, a series/sep-ex are by far the best EV motors you can
buy and what I'll use for now.
Jerry Dycus
>
> Jeff
---------------------------------
All-new Yahoo! Mail - Fire up a more powerful email and get things done faster.
--- End Message ---
--- Begin Message ---
Mike,
Congrats on the charger. If you go to the evalbum tech files section it
shows the light dimmer charger. http://www.austinev.org/evalbum/tech/
I used a similar design with an autotransformer. Mike hasn't put the page
up yet, but I can email you the jpg schematic if you like.
Either one is inefficient and won't properly charge the batteries, but is
good in an emergency. Battery's cost $2K - $3K. A good charger will keep
them going for years. This charger will probably not. I recommend saving
up for a Zivan or Russco, but ideally the PFC 20 at the least.
In my setup, I choose the input tap so that I keep the current draw under
15 Amps (the house breaker setting) using the Sears amp clamp.
I got 65% efficiency. THis number only goes down as the vehicle charges.
Comparison. The Zivan got 85%-90% efficiency if I recall.
The light dimmer concept should also work to limit the input current to
prevent tripping the breaker. If you have an emeter, you can estimate your
power draw by dividing the
emeter Amps/0.65= AC input amps
Good luck,
Ben
PS: you're not isolated. Put an on off toggle switch somewhere and use a
GFI outlet.
A timer is also recomended $20 at Home depot, because you will overcharge
your batteries if left on too long (over 10 hours). (I think 196 VDC)
wheras max would be My setup with 156 VDC batteries can not overcharge
because the 120 VAC outlet *~1.4 (AC sine wave "don't quote me" doesn't
exceed the max battery charging voltage (somewhere around 185-200)
whereas for 120 Volts of batteries, you will (after many many many hours).
--- End Message ---
--- Begin Message ---
Crikey Rich, you should cut the bloke some slack in the crudeness department,
after all, he can't help himself, he's Australian. Seems to me that arrogance
has always been a virtue on this list...I can't distinguish any of you guys
apart.
-Myles
-------------- Original message --------------
From: "Rich Rudman" <[EMAIL PROTECTED]>
> Your arrogance Befuddles our Brilliance..
>
--- End Message ---
--- Begin Message ---
Not really a vehicle, but it's electric and fast...
http://fastmhz.com/viewtopic.php?t=58
1.7 kv from a 12v 5ah battery.
--- End Message ---
--- Begin Message ---
Wow, I'm even more confused.
With an AC motor, you need an external electronic inverter, right? So what's
the benefit?
And do you need an external inverter with something like the Brushless DC if
it's simply a Syncronous AC? Or do you not need a inverter with the
Syncronous AC? And if either is the case then why differentiate the motors
at all????
Nobody has to answer this. I just really need to bone up on electrical
engineering.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: Wednesday, September 27, 2006 11:37 AM
To: [email protected]
Subject: Re: AC vs DC?
Michael Trefry wrote:
> Please excuse my ignorance, I'm just trying to understand.
>
> How can DC be the same thing as AC?
>
> If I'm not mistaken, DC is direct current, meaning a steady stream of
> electrons going in a single direction, while AC is alternating meaning
that
> it's constantly going back and forth. Right?
>
> There is no +/- with AC right?
All motors are AC. There has to be AC in the coils, or the motor is very
inefficient and awkward. What you think of as a DC motor is really an AC
motor with a mechanical inverter (the commutator and brushes) that
converts the incoming DC power into AC.
Surprising, but true!
--
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 Mike;
OK you're just down the road! Had a kid do 4 years at UCONN, so I'm VERY
familier with Storrs.Cool, we meet at my place in Killingworth, about an
hour down the back roads from Storrs. We have at least ONE show up, I mean
cars, I have some EV's in various stages of construction, right now.Some
Electracs and lots of parts an' goodies, about the house.As for guyz? Well,
it varies, but usually a dozen or so, depending on their other commitments.
There is ANOTHER EV Chapter, up in Amhearst MA, too. I havent been up to
their gettogether, yet. I should, to try to help support the Club thing.I
think ?? they are the FIRST week, of the month, we are the Second Sat, each
month.We set it up that way for the Two Timers, to get both in in one month.
If we can talk Dave Cover into coming down, we would have more cars, Hint
Hint<g>!CT isn't exactly a hotbed of EV activity, I'm afraid.But we are
working on that. I know you guyz are out there. Just rounding them up is
like trying to heard a bunch of cats!Well, that seems to be for EV guyz
EVerywhere? Just because gas is almost being given away, under 250 a gal in
Corrupticut, it's a ploy as it is election time, it looks good, but, guys,
don't think it will last. Get your EV's running so you will be ready for the
5 bux a gal, stuff. Coming to a gas station near you ,soon!We haven'rt had
any good hurricanes or some other natural calamidy, to use for an excuse to
run the prices up.Again.
Lousy hurricane season!Good thing!No storms worthy of mention. See?
Keeping a generater primed and ready to go keeps them away! Has worked for
me for years! And I'm ready when the power goes off for no reason, for
HOURS! On a sunny nice day!OK back to AC Vs DC.
Seeya
Bob
----- Original Message -----
From: "Michael Trefry" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, September 27, 2006 9:04 AM
Subject: RE: Join In! WAS : AC vs DC?
> I'm in Storrs, next to UCONN.
>
> So how many people show up at those? Are there a lot of cars?
>
>
> Mike
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Dave Cover
> Sent: Tuesday, September 26, 2006 10:46 PM
> To: [email protected]
> Subject: RE: Join In! WAS : AC vs DC?
>
> Mike
>
> You're not entirely alone. Bob Rice is down in Killingly (Killingworth?),
> one of those places. I'm up in Canton. You can't be too far. Where in the
> state are you? Bob has been hosting the local EAA meeting lately, about
once
> a month. That's a good place to meet your EV neighbors.
>
> Dave Cover
>
> --- Michael Trefry <[EMAIL PROTECTED]> wrote:
>
> > I'm in CT.
> >
> > I haven't seen much of an EV movement up here. Not much in the way of
> > alternative energy at all.
> >
> > The only thing I've seen in this area is NG vehicles.
> >
> > Mike
> >
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.405 / Virus Database: 268.12.8/455 - Release Date: 9/22/06
>
>
--- End Message ---
--- Begin Message ---
The recent discussion on Heinemann breakers caught my interest.
I was thinking of using a 700 amp version of the GP1P series for a manual
disconnect on my EV. The units are rated at 160V DC with an interupt ability
of 10,000 amps (1.6 mwatt).
These breakers can be had for relatively cheap on ebay. I am thinking of
using the breaker for my manual disconnect on a 288V system. My logic here is
that on a battery powered system, I will never get to 10,000 amps. On the pb
batteries, at maximum power output, the voltage would be 1/2 peak voltage ie
144 volts. Short circuit current is 2400 amps at 0 volts. I also think these
breakers are made for inductive loads so that they can easily handle voltage
spikes well above their voltage ratings.
The EV will also have Gould dc fuses for rated protection.
Has anyone else used these breakers at above rated voltage. Comments?
EZEsport
---------------------------------
Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates
starting at 1¢/min.
--- End Message ---
--- Begin Message ---
Try Electric Motors and Control Techniques (Paperback) ISBN 0070240124
I got it from Amazon for about 17.00 and it covers ac & dc in some detail. good
primer
Pedroman
----- Original Message -----
From: "Don Cameron" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, September 27, 2006 1:31 PM
Subject: Books or References on AC Motors and Controllers
> Can anyone recommend books or websites on an introduction to AC motors and
> controllers. I am technically capable so no problem with basic electronics,
> microcontrollers and mathematics.
>
> thanks
> Don
>
>
>
>
>
--- End Message ---
--- Begin Message ---
Hi EVerybody;
I had to chime in here. Yes, take it home with you! Take out the CAV
motors, they are about the same size as the 9" ADC motors. I bought 2 from
MY friemdly Junkyard, Loose they have the #$%^@ Female non shafts. You hafta
bore out the hole and press and weld a NEW shaft in there. Pain in the ass.
But doable. The One Way, two terminal thing shouldn'tr be an issue UNLESS
you're converting a Honda?It runs the same way my 9" in the Rabbbit did.
CAV's are sure not common!I think they are a compound setup so they won't
overspeed to death if they get unloaded?I'm sure Jim Husted has run across a
few CAV's in his travels? Now Jim could do it right?Press in a useable
shaft, rewind the fields for series, bring the field and arm comnnections
out, so you would have 4 hookups, time it for best running in one direction,
and you would have a nice ballsy EV motor!A little tweeking herean' there?
My two watts worth.
Bob
----- Original Message -----
From: "Mark McCurdy" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, September 27, 2006 1:05 PM
Subject: Re: Parts worth salvaging?
> Get the batteries too.
> Think core-charge *shudder*
>
> ----- Original Message -----
> From: "James Massey" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Wednesday, September 27, 2006 3:35 AM
> Subject: Re: Parts worth salvaging?
>
>
> > At 09:23 PM 26/09/06 -0700, John wrote:
> >>I have permission to salvage parts off of a Hyster Hi-Racker that is
> >>destined for the scrap dealer. It is a 72 volt unit with 2 motor in
wheel
> >>units and three hydraulic pump motors.
> >
> > Yes, yes, get!!
> >
> > Wheel motors are probably too much trouble to use, but the EV1,
> > Contactors, non-wheel motors, look for a DC/DC converter, too. Cables
may
> > be useful, if not too corroded.
> >
> > EV1 will do for a light car, a bike or a trike, not necessarily with one
> > of the motors from this, though. But yes, get, if not for yourself, then
> > another EVer.
> >
> > Regards
> >
> > [Technik] James
> >
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.405 / Virus Database: 268.12.8/455 - Release Date: 9/22/06
>
>
--- End Message ---
--- Begin Message ---
Wow - launch at 109 m/s, or approx 250 mph.
That should give you a good 60 ft time!
Interesting device, reminds me of the coin shrinker
though that device is so powerful that it vaporizes
the energizing coil every discharge, here he only
desolders his coil and he uses 3 SCRs in parallel...
Ho wmany can say they have a device recharging from a
12V 5Ah battery (probably through a 100W DC/AC inverter
driving the HV transformer, I bet it's 120V to 480V AC)
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Harry Houck
Sent: Wednesday, September 27, 2006 10:12 AM
To: [email protected]
Subject: FAST EV - OT
Not really a vehicle, but it's electric and fast...
http://fastmhz.com/viewtopic.php?t=58
1.7 kv from a 12v 5ah battery.
--- End Message ---
--- Begin Message ---
Ray Wong wrote:
The recent discussion on Heinemann breakers caught my interest.
I was thinking of using a 700 amp version of the GP1P series for a manual disconnect on my EV. The units are rated at 160V DC with an interupt ability of 10,000 amps (1.6 mwatt).
These breakers can be had for relatively cheap on ebay. I am thinking of using the breaker for my manual disconnect on a 288V system. My logic here is that on a battery powered system, I will never get to 10,000 amps. On the pb batteries, at maximum power output, the voltage would be 1/2 peak voltage ie 144 volts. Short circuit current is 2400 amps at 0 volts. I also think these breakers are made for inductive loads so that they can easily handle voltage spikes well above their voltage ratings.
The 10,000A rating is the UL rating. The datasheet also points out that
the "NON-UL" rating is 14,000A @160V.
The EV will also have Gould dc fuses for rated protection.
Has anyone else used these breakers at above rated voltage. Comments?
EZEsport
---------------------------------
Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates
starting at 1¢/min.
--- End Message ---
--- Begin Message ---
Perhaps we should throw out the term DC entirely. As others have mentioned,
all modern electric motors are AC systems. The difference lies in their
magnetic fields and how they are commutated and controlled. Motors can be
commutated mechanically or electrically (commutation refers to the switching
of the motor coils). They can be controlled by applying varying voltages,
frequencies, pulse-widths, etc. The accuracy of control depends on the
feedback (or lack thereof) system and the speed and resolution of the
sensing and commutating circuits.
Wow, I'm even more confused.
With an AC motor, you need an external electronic inverter, right? So what's
the benefit?
And do you need an external inverter with something like the Brushless DC if
it's simply a Syncronous AC? Or do you not need a inverter with the
Syncronous AC? And if either is the case then why differentiate the motors
at all????
Nobody has to answer this. I just really need to bone up on electrical
engineering.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: Wednesday, September 27, 2006 11:37 AM
To: [email protected]
Subject: Re: AC vs DC?
Michael Trefry wrote:
> Please excuse my ignorance, I'm just trying to understand.
>
> How can DC be the same thing as AC?
>
> If I'm not mistaken, DC is direct current, meaning a steady stream of
> electrons going in a single direction, while AC is alternating meaning
that
> it's constantly going back and forth. Right?
>
> There is no +/- with AC right?
All motors are AC. There has to be AC in the coils, or the motor is very
inefficient and awkward. What you think of as a DC motor is really an AC
motor with a mechanical inverter (the commutator and brushes) that
converts the incoming DC power into AC.
Surprising, but true!
--
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 ---
Don Cameron wrote:
The other alternative is to question what use is the compass anyways?
Think computerized mapping. Most of the time the map is oriented so
that your direction of travel is up on the screen.
Don
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "David Roden"
Check the battery temperatures - I suspect you're heating them up. This
lowers the finish voltage. They may be going into thermal runaway.
Others will no doubt disagree,
David's info has always looked good to me , I have seen this also , I think
as the water/acid gets stronger vs needing water the voltage goes up easier.
know I'm supposed to kill my first
pack, but I've been being careful. I've limited the
current draw to 350A max and the voltage to 130V
minimum. I have run the truck at the low voltage limit
occasionally, but not for any extended period of time
and the voltage always comes back immediately after
Not all people kill there first pack , I think we just tell you that so
you'll be careful and being on the list should help that . Its good you
added water after charging .
The charger never shut off, it ran all night
at 10 amps. I drove it to work and back the next
morning, and fired the charger up again. I kept an eye
on things and the voltage never reached 186V to
trigger the CV stage
This is not good ,,,,
but I think US Battery's recommended finish
voltage is too high. I use 2.5 volts per cell for new batteries,
gradually
reducing it as they age.
More good advice , what happens with me allot of time is things are going
fine , for a long time , then I change something ( like watering ) and now
things are different all of a sudden . If you weren't paying attention ,
like Joe 6 pack , for the next few months you'd cook your batteries , then
wonder why they died so young . I'm not an expert on batteries , I just use
them and after 10 years I can still say " I'm still learning how to take
care of them " . What we really want is a BMS that doesn't burn off power to
equalize but uses that power to run a computer to figure out what the
battery is saying :-) . back to the real world . What I do something is get
the batteries some what fully charged , let the cool off of 6 hours , then
turn the charge on low like 3 amp, and let it charge for another 4 hours ,
then turn the charge all the way up or to what ever amperage you normally
charge to , the voltage will rise to a certain point and not go any higher
, then adjust the voltage ( you know that little screw that's so hard to
get to:-) till the blue light comes on . Now the next time you charge see if
the charger cycles right . Another thing to look for is when you get in and
drive , pick a load like 100 amps and check your voltage while under this
load ( do this after a mile of driving to remove the sirfuss charge (
spell checker let me down of curfis )) . This is a number that will change
as the battery gets older or if its not fully charged. As your turning the
voltage down on the charger over the next few weeks , keep an eye on this ,
If you see the voltage getting lower then you are not fully charging the
batteries.
Also, unless you've added some goodies to that PFC charger, you don't have
temperature compensation, so you should (theoretically) be tweaking the
finish voltage to match the batteries' internal temperature.
A better and safer (IMO) approach is to use DV/DT instead of absolute
voltage. Get the voltage above 2.3 to 2.4 volts per cell and then wait
for
the voltage to stop rising. If it begins to >fall< , stop right away.
I think this is the one thing we can say for sure "If it begins to >fall<
, stop right away."
Steve Clunn
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Want to unsubscribe, stop the EV list mail while you're on vacation,
or switch to digest mode? See how: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
Note: mail sent to "evpost" or "etpost" addresses will not reach me.
To send a private message, please obtain my email address from
the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
--- End Message ---
