EV Digest 2565
Topics covered in this issue include:
1) Re: Battery replacement time!
by [EMAIL PROTECTED]
2) Re: Battery replacement time!
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Dump charger with no manners
by "1sclunn" <[EMAIL PROTECTED]>
4) Re: ampabout
by "Chuck Hursch" <[EMAIL PROTECTED]>
5) Re: Fun with EV's
by "Chuck Hursch" <[EMAIL PROTECTED]>
6) EVLN(Aussie robot-driven EVs)
by Bruce EVangel Parmenter <[EMAIL PROTECTED]>
7) EVLN(UK Cell & Laptop Recharge Kiosk pushes batt technology)
by Bruce EVangel Parmenter <[EMAIL PROTECTED]>
8) Re: EVLN(UK Cell & Laptop Recharge Kiosk pushes batt technology)
by Bruce EVangel Parmenter <[EMAIL PROTECTED]>
9) Re: ampabout, Electric Tram proposal
by "Mark Hanson" <[EMAIL PROTECTED]>
10) Re: EVLN(UK Cell & Laptop Recharge Kiosk pushes batt technology)
by Lock Hughes <[EMAIL PROTECTED]>
11) Re: Dump charger with no manners
by Lee Hart <[EMAIL PROTECTED]>
12) light-wieght alternators
by Grant Young <[EMAIL PROTECTED]>
13) RE: light-wieght alternators
by "amadare" <[EMAIL PROTECTED]>
14) RE: 48 Volt charger wanted...
by "Chris Tromley" <[EMAIL PROTECTED]>
15) EV parts delivery service. Racers take note.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
16) 75Ah Optima
by "Edward Ang" <[EMAIL PROTECTED]>
17) Re: light-wieght alternators
by Lee Hart <[EMAIL PROTECTED]>
18) RE: light-wieght alternators
by "Andre Blanchard" <[EMAIL PROTECTED]>
19) Re: 75Ah Optima
by "damon henry" <[EMAIL PROTECTED]>
20) RE: 75Ah Optima
by [EMAIL PROTECTED]
21) Re: light-wieght alternators
by Victor Tikhonov <[EMAIL PROTECTED]>
22) RE: 75Ah Optima
by "Yoder, Chris" <[EMAIL PROTECTED]>
23) Re: light-wieght alternators
by Rod Hower <[EMAIL PROTECTED]>
--- Begin Message ---
Lee,
I thought Nawaz recomended C/30 for finish not C * 0.02 (2%) and shutdown when the
voltage rises less than 0.04 / cell / hour. Would 2% produce less gassing
but still use the same shutoff point? That would actully be more convienent
for me as the Tropica's charger already does 14 amp and 5 amp. I was converting
it to 7.5 amp (225 / 30). I've got the micro measuring voltage and was just about
to start modifing the charger.
thanks,
Steve
>If you have good tight caps, and your charger limits current to less
>than 2% of the battery's amphour capacity when it is above the gassing
>point, you should have little if any leaking or corrosion. This means
>the charger should be under 5 amps when the voltage is over 7.1v for the
>EV-145.
>
--- End Message ---
--- Begin Message ---
[EMAIL PROTECTED] wrote:
> I thought Nawaz recomended C/30 (3.33%) for finish, not 2% (C/50)...
That's correct. The usual range is 2% to 4%. I go on the conservative
side with 2%. Nawaz at US Battery is a bit more aggressive.
> shutdown when the voltage rises less than 0.04v / cell / hour.
That's the dv/dt algorithm, used in many large industrial chargers. It
works great, but you still should look for the voltage to at least get
to the gassing point (2.37v/cell, 7.11v on a 6v battery, 14.22v on a 12v
battery, etc.) before using it. Otherwise, an old battery won't get to
full charge before its dv/dt falls to less than 0.04v/cell/hour.
> Would 2% produce less gassing but still use the same shutoff point?
Yes.
The downside to using 2% is that it won't be enough as the batteries get
old. You'll have to crank up the finishing current or you won't reach a
reasonable ending voltage (or it will take forever to get there).
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Thanks Lee this was the info I was looking for . replaced the ic's and found
that one of the IGBT's was still good but didn't get to "fire it up" this
week maybe next.
>
>
> For a buck converter, you decide how much output current ripple you
> want. For example, 10 amps +/-10%. This would mean the average current
> is 10 amps, and is actually going from 9 to 11 amps.
I got a feeling that a standard "bad boy" charger must have a high ripple
as no current flows most of the time(when ac sine wave is under that bat
voltage) . for charging bats though 10 % would seem very good .The ripple is
harder on the transistor's than the bats I'll bet.
> Next, you pick your operating frequency. As mentioned above, a lower
> frequency is easier on the transistor, higher is easier on the inductor.
> For the sake of argument, let's say 2 KHz.
>
> Now, the equation for the inductance needed is V = L x di/dt, where V is
> your input voltage, L is your inductance i henries, di is the peak-peak
> change in current in amps, and dt is the time in seconds for one cycle
> at your switching frequency.
The higher the ripple the bigger the di ?
am I correct in thinking that the Max on time for the power transistor
should not be more that 50%
> Current is going between 9a and 11a. Assume your input voltage is the
> rectified and filtered 120vac, so V = 120vac x 1.4 = 168vdc. The time
> for one cycle is 1 /2KHz = 0.0005 seconds. Rearrange the equation, and
> solve for L:
>
> L = V / (di/dt)
> = 168vdc / (11a-9a)/0.0005sec
> = 0.042 henries, or 42 millihenries
>
that would = 42,000 uh ? I better start winding.
.
>
> That's the next problem. Inductors saturate above some current, and
> their inductance goes away. Since there is an average DC current flowing
> in the inductor, it has to have an air gap or it will saturate at a very
> low current. If you are using a toroid, people usually use a mopermalloy
> core because it has a built-in distributed gap. Other types of cores
> will require a slot.
I have a few that I'm playing with , one a 1kw antenna balum , some 60
cycle trodoed's that I can re wind. and so other supplus stuff.
> If your core saturates at high current, its inductance falls
> drastically. Then your transistor's peak current shoots WAY up, and the
> transistor is destroyed. This is why you should have current limiting;
> to save the transistor in case the core saturates.
>
> To tell if your inductor is saturating, look at the current flowing in
> it. It normally rises and falls smoothly. If it saturates, it suddenly
> starts rising much faster when the current exceeds the saturation
> current. You usually put a shunt or current transformer in series to
> measure current.
>
> > Trying different coils I've noticed that on some the wire gets hot
> > and on others the toroid gets hot.
>
> If the core gets hot, it is saturating, or being driven at too high a
> switching frequency. If the wire gets hot, it is from simple I^2R
> heating.
>
> > I've also read where over 500 watts they use a full bridge setup
> > for DC/DC converters.
>
> There are several reasons for this. One, a simple one-transistor buck
> converter has a huge input current ripple (0 amps, full amps; 0 amps,
> full amps). So you need a huge input filter capacitor. As the power goes
> up, the size of the input filter capacitors gets unreasonable. A half or
> full bridge has less ripple, so the capacitors are much smaller.
>
> Another is that the single transistor has to switch the converter's full
> power, voltage, and current. A half or full bridge splits the power up
> between multiple transistors, so they operate at lower stress levels.
> This lowers cost, and indirectly improves efficiency.
>
> And, the more sophisticated circuits can do power factor correction,
> which gets progressively more important as you go to higher power
> levels.
> --
> Lee A. Hart Ring the bells that still can ring
> 814 8th Ave. N. Forget your perfect offering
> Sartell, MN 56377 USA There is a crack in everything
> leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
>
>
--- End Message ---
--- Begin Message ---
Bruce EVangel Parmenter wrote:
> I figure the only jobs that are robust right now are
> services for the rich/well-paid, as well as the
> home-land-security push. I thought I would explore
> being a security guard (Do you want boredom with that?).
>
[snip]
> But never fear, this is where the HOV sticker and the extra
> amp hours come in handy.
>
> I fished my way over left two lanes, to time my entry into
> the HOV lane. From a dead stop I opened my controller up
> and got up to speed just to slow down.
I got visions of the big truck `putting the hammer down and
rolling up to speed...' Yahoo!...
>
> Oddly enough and to my advantage, it wasn't the EV going
> the speed limit that frustrated SUVs in the HOV lane.
>
> The two in the Honda Accord in front of me were stoned,
> and only going 50 mph. After a spacey episode had passed
> (they were not hearing all the SUVs honking behind me),
> they sped up. By that time, it was my time for me to leave
> the HOV lane and head for my Hwy exit.
I might not be willing to roll 70mph in a HOV lane next to a lane
with stopped or very slow traffic. All it would take would be
one car pulling right out in front of you, and poppo! Not good.
>
> I got back home with -79ahs on my emeter. 45ahs for 17 miles
> of wind pushing on the highway. See, mooching pays off.
Do you see any sign of your new tires wearing the sticky new
stuff off and rolling easier? My Integritys may be doing such,
I'm not sure. If you can avoid getting stuck to the road with
new tire goo the first thousand miles, you may have a chance...
I know I have one cell down at <1170sg and one other somewhat
weak (~1235sg), so if I get those kicked out of my 1.5 year old
pack, I may do better. What do we figure? - 5% cell failure rate
pretty early in the game? - I only have 3-4000 miles on my pack.
I purchased 4 spares in addition to the 16 T125s for the pack.
The spares have been exercised lightly, but have not seen the
many 350A hill climbs and several 50%-capacity discharges. It
will be interesting to start moving them into the pack prior to a
battery management system being implemented (I hoped to the
beginnings of one by now, but that's life...).
>
> ...
> So, if I get the guard job after their training, I will be
> earning my pay by working to stay awake from boredom, while
> praying that the field service jobs I applied to will call
> and rescue me :-o
You have a lot of hi-tech skills. Maybe you could work in the
security field, maintaining some of those machines for the DOD,
etc. I know there is a lot of money being pushed into
biometrics, AI, and the like. Do you have some software
training?
Chuck Hursch
Larkspur, CA
NBEAA treasurer and webmaster
www.geocities.com/nbeaa
http://www.austinev.org/evalbum/339.html
--- End Message ---
--- Begin Message ---
Bob Rice wrote:
> Write ON !, when I get a Good One, I'll send it along.
John , If yur
> listening, you're missed , by those who love ya! Come on back
No questions
> asked<g>!I'll try to send some good ones, myself.
I second that, John. I enjoy reading of your sagas, tire smoke
and all! Your enthusiasm is infectious!
Chuck Hursch
Larkspur, CA
NBEAA treasurer and webmaster
www.geocities.com/nbeaa
http://www.austinev.org/evalbum/339.html
--- End Message ---
--- Begin Message ---
EVLN(Aussie robot-driven EVs)
[The Internet Electric Vehicle List News. For Public EV
informational purposes. Contact publication for reprint rights.]
--- {EVangel}
http://www.theage.com.au/articles/2003/01/29/1043804407134.html
Robot chauffeurs approaching fast January 30 2003
By Garry Barker Technology Editor
Miniature robot-driven cars go through their paces.
The halcyon day of the robot chauffeur is approaching. With
Australian technologies already successfully tested in
Queensland and on roads near Versailles in France, you will
eventually be able to sit back in your car sipping a glass
of wine, reading, chatting on a mobile phone or watching TV
and have the vehicle drive you smoothly, safely and
automatically to your destination.
Ljubo Vlacic, of the School of Micro-electronic Engineering
at Griffith University, who leads the team that developed
the technology, says it is ready for commercial application
but he does not expect to see it in public operation for
some years.
More likely, he says, car manufacturers who are already
showing interest, will begin by building a limited number of
automated manoeuvres into conventionally controlled cars.
"For instance, if you don't like parking, you could have the
car do it for you automatically, just by pushing a button,"
Professor Vlacic says. "Or you could program your car to
handle heavy traffic using a stop-go 'cruise control' system
to always keep a safe distance behind other vehicles.
"We are talking about cooperative autonomous vehicles," he
says. "They rely on sensors carried on the car and on
communication with other cars similarly equipped, and might
provide automated services such as transport from your home
to a railway station."
But the robot cars will also be able to move safely along
roads among conventional cars controlled by humans, avoiding
collision and following pre-programmed directions, he says.
Engineers in Europe and the US have been working with
limited success on automatic guidance systems for cars for
more than a decade. Generally they have used magnetic cables
laid in the roadway for vehicles to follow - horrendously
expensive if every road in a country as large as Australia
was to be equipped for automatic driving.
The system developed at Griffith University is
self-contained and can be used on conventional roads, using
on-board electronic sensors to avoid other vehicles, and to
deal with intersections and stop lights. Digital maps using
satellite positioning and other techniques are used to guide
the vehicle along its journey.
Initial research has been done using miniature robot cars
and the French tests with full-scale electric vehicles, he
says. "Electric cars are easier for us to connect with our
computers to control the wheels," he says. "Conventional
cars could be adapted as well."
-
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--- Begin Message ---
EVLN(UK Cell & Laptop Recharge Kiosk pushes batt technology)
[The Internet Electric Vehicle List News. For Public EV
informational purposes. Contact publication for reprint rights.]
--- {EVangel}
Technology - NewsFactor
Recharging Kiosk Empowers Mobile Gadget Users
Wed Jan 29, 1:33 PM ET
Tim Bresien , Wireless.NewsFactor.com
Startup Charge Me, part of the Near Telecom group of
companies in the United Kingdom, was founded just last year
by entrepreneurs from the mobile telecom and manufacturing
industries for the purpose of addressing a growing mobile
power problem. The company says its first product, the CM1
Recharge Kiosk, is designed to promote wireless operator and
handset manufacturer brands while enhancing the experience
of the mobile subscriber. Additional products are in
development.
The cylindrical kiosk, measuring about 5 feet tall and 24
inches in depth, features 12 padded bays that allow users of
many of today's popular handsets and PDAs to plug in and
receive a power boost. It also can be built to incorporate
advertising concepts and signage.
"It's quite simple. Public power charging has never properly
been addressed with a product," Charge Me director Dr. Janko
Mrsic-Flogel said in a conversation with NewsFactor. "The
Charge Me CM1 kiosk allows travelers and passersby to
recharge their mobile devices when they are low on power or
have run out of juice entirely."
Power Struggle
There is a growing awareness in the wireless industry that
robust applications like mobile gaming and MMS (multimedia
messaging service) are creating a power crisis. Talk time
and standby time are still the standards handset
manufacturers use to gauge battery endurance -- but at the
same time, they are touting their multimedia-optimized
screens and polyphonic sound capabilities. It is a safe bet
that game time falls far short of talk time.
The more time subscribers put into hunting invaders from
outer space, viewing e-mail attachments and monitoring the
latest swings in their investment portfolios, the more
likely it is that they will put themselves at risk of
running their devices down or out. Smartphones, many of
which add the full functionality of PDAs and MP3 players,
are still at the mercy of one onboard power source.
Running Behind
Battery technology and power engineering always seem to be a
half generation behind the favorable applications of the
day. Otherwise, electric cars would be more than just golf
cart-size curiosities, and the battery displays at your
local drug store would be getting smaller instead of taking
up half an aisle.
"In general, trends are to increased power consumption,
particularly video on 2.5G and 3G," Aberdeen Group research
director Russ Craig told NewsFactor. "The other thing that
is happening is the use of non-volatile memory in cell
phones and PDAs, so if the battery goes dead you don't lose
your data or phone numbers or ringtones."
Power to the People
Charge Me sees two types of venues for the CM1. In public
transportation hubs and public gathering places, the CM1
will be a coin- or bill-operated vending machine that
typically will dispense power boosts in 5- or 10-minute
increments. In UK trials, a British pound (about US$1.50)
bought a 10-minute charge.
The second type of venue will feature the CM1 in a corporate
or complimentary retail setting. Businesses may find value
in placing the Charge Me kiosk in convenient locations for
their employees who are heavy mobile users, while retailers
and hospitality managers may find that free charges lead to
impulse buys of their primary products. After all, they will
have a captive audience for at least 5 or 10 minutes.
Positive Reactions
"Charge Me expects positive reaction to its first
installations in Q1 this year," said Mrsic-Flogal.
"Following the pilot installation findings, we aim to step
up production and deploy nationwide (UK) with our pilot
partners, such as Railtrack, which manage most of the main
railway stations in England."
Charge Me's kiosk is designed to be accessible to a very
broad range of users, who operate a variety of wireless
devices. Currently, the 12 bays of the initial CM1 product
can recharge more than 50 popular mobile phone and PDA
models.
>From Spare Batteries to Power Stations
Power solution vendors are attacking the problem from
different angles. For example, Aberdeen's Craig mentioned
two heavily funded startups, MobileWise and Splashpower,
that are designing power transfer stations. They look like
desktop pads and can charge devices just by being in contact
with them.
Simpler strategies are being employed by companies like IST,
whose Sidewinder product is a manual charger that can give
up to 5 minutes of emergency power when its rotary crank is
turned for 2 minutes. And you can also find PDA solar panels
on the market, along with more traditional backups like
spare batteries and universal AC adapters.
The CM1 will be charging into dozens of UK locations early
this year, with an elegant and user-friendly design that is
also an advertising trojan horse for its owner. If today's
wireless multimedia and mobile data applications really
catch on, you may find yourself looking for a kiosk soon.
-
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--- Begin Message ---
What if ...
The laptop and cell batt use pushed the development and
availability of less expensive, higher density, batts?
The Kiosk idea contributed to the knowledge of how easy
it is to recharge, hopefully over coming all the
hybrid hype of 'you don;t have to plug it in'.
Like the latest Honda Civic hybrid TV ad that comes on
like coverage of a LA high speed chase: one of the
hosts asking if that Electric is ever going to need a
recharge, the hybrid stops in the middle of a 7-11
wannabe, the driver runs out as if he is running away,
just to have the driver run back with sugary junk food
and drive off (meaning he not the hybrid needed recharging).
Odd, how no one jumped in the car and drove off. Or
went postal about his bozo blocking other cars trying to
leave by stopping his hybrid in the middle of the lot
with his ICE running.
Its ads like these that continue the confusion the public
has. They do not like to be told the truth that their car
is not Electric, is a hybrid ICE with assist.
:-zzz
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--- Begin Message ---
Here's something to try Bruce, converting the diesel trams at Disney to
electric with fast charging (inductive coils under the pavement or
conductive connectors at stops) stations at pick-up and drop-off parking lot
points. I submitted a proposal and havn't heard back. Maybe you or others
could too. It's the only thing there that isn't electric. Also I heard the
speach also on Fool Cells and was interesting to hear the same sillyness
back in December at the EVAA convention for $300k cars in 30 years.
----- Original Message -----
From: "Bob Rice" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Wednesday, January 29, 2003 11:11 AM
Subject: Re: ampabout, OT a bit an' Stuff.
>
> ----- Original Message -----
> From: Bruce EVangel Parmenter <[EMAIL PROTECTED]>
>
> > Not-a-peep from Intel. After prodding the contract agency, I
> > found I was not chosen. So, I switched tactics by applying
> > to a flurry of non-HiTech jobs (Do you want fries with that?).
> >
> > SNIP Snip> ...
> > So, if I get the guard job after their training, I will be
> > earning my pay by working to stay awake from boredom, while
> > praying that the field service jobs I applied to will call
> > and rescue me :-o
> >
> > Hi EV ereybody;
>
> What a stunning indightment to the "State of the Union" Chat the prez
> was on, last nite, on the Radio! Along with that, out here, Airline
pilolts
> asking me if they could get a job flying the Acela, train. A bit of a"
> comedown", for them, but it would put food on the table. Oh, they would be
> welcome in better times, ya hafta start as a conductor, and work into the
> Eng. training program, "Choo Choo U. as we call it. But, don't ask! As
> Amtrak, like most airlines, is fighting for it's life, as I speak, in
> Congress. The Prez DOD talk about Fool cells, but didn't breathe a word
> about EV's that exist already, or mass transit?Money for this, money for
> that. God! The National debt is gunna go through the roof! Guess the only
> reason I have a job still is they can't pick up the RR and move it to
China
> or Mexico, so they can pay the help 29 cents a day to run it. I am very
> lucky this way. Of course if Amtrak bombs, I'll be looking like Bruce, but
> to quote the line in the Movie "Titanic, Bruce Ismay ,White Star Line CEO;
> "'But......She can't Sink!" But She DID, and ruined alotta folks' day.
>
> But you wouldn't know this, looking about, roads choked with shiny
SUV's
> 4and 5 Hundred thou houses selling like hotcakes in CT, the modest, say,
1k
> or 150k ranches being buldozed under for the LOT! To build SUV houses I
> call them, BIG obnoxious Tara like houses. Silly size, for two people!
When
> I was a kid on Long Island , houses that size bore names and were Summer
> Resorts "The Point House' The Dunes" They need a shuttle bus(electric) to
> get around in them.Bathrooms the size of bedrooms, living rooms the size
of
> Gyms! Waste! Waste! No wonder the kids grow up without parents! They both
> hafta work, work, work, to pay the mortgage AND the heating bills for
these
> palaces. Show show show,"Look at me look at me NOW! " said the Cat in the
> Hat, , 3 car garage for the SUV and Mercedes or Porsche. Gotta remember to
> pick up the kids at daycare, swing by the Stupermarket for prepared meal
to
> take home. Don't have time to fix dinner, or sully that designer kitchen,
or
> stack the dishwasher, with dirty dishes.
>
> Don't know where it's leading or the Answer, If I did, could have a
> fancy job in Washington, guiding the USA sinking ship of state, to run it
on
> the beach, to effect repairs. Hafta take my little niche, developing and
> running working EV's one car at a time. My State of the Union address, to
> all the other guyz out there working and driving EV's The technology will
be
> here when needed, whenEVer.
>
> OK back to Evercells and million lb trucks, going up grades<g>! An' a
> better heater for the Rabbit. It doesn't make it @ 5 below, the other
nite!
>
> My 500 ohms worth.
>
> Seeya
>
> Bob
>
>
>
>
>
--- End Message ---
--- Begin Message ---
--- Bruce EVangel Parmenter <[EMAIL PROTECTED]> wrote:
> What if ...
> The laptop and cell batt use pushed the development and
> availability of less expensive, higher density, batts?
This may already be happening Bruce:
www.electrovaya.com/
>From their August 2002 quarterly report:
"Announced partnership with CAMI Automotive Inc. to develop a zero
emission vehicle utilizing Electrovaya�s battery, power and control
technology".
Their May 2002 Press Release describes CAMI as a a joint venture
company between General Motors of Canada Ltd. and Suzuki Motor
Corporation...
A couple of other bits from their site:
SuperPolymer batteries have an energy density of 470-watt hours per
liter.
Our lithium ion polymer technology allows us to make batteries in thin
sheets that we can stack, fold or otherwise shape to fit the desired
form. We believe this flexibility allows us to accommodate both small
size applications like portable computers and mobile telephones and
larger potential applications like electric vehicles.
Lock
______________________________________________________________________
Post your free ad now! http://personals.yahoo.ca
--- End Message ---
--- Begin Message ---
Steve Clunn wrote:
> I got a feeling that a standard "bad boy" charger must have a high
> ripple, as no current flows most of the time (when AC sinewave is
> under that bat voltage). For charging bats though 10% would seem
> very good. The ripple is harder on the transistor's than the bats
> I'll bet.
Exactly right. Most chargers are just a transformer and rectifier; no
filtering at all. Current ripple is extremely high. A 10 amp average
current on the meter is really going from 0 amps at the zero crossings
of the AC line to 20 amps (or more) at the peaks).
Batteries generally don't care. Ripple doesn't bother them unless it
gets REALLY big -- like 10 amp spikes 1/10th of the time to achieve a 1
amp average charging current.
>> the equation for the inductance needed is V = L x di/dt
> The higher the ripple the bigger the di?
Yes. Ripple is the max current minus the minimum current. If the current
is going from 9 amps to 11 amps in each cycle, the peak-to-peak ripple
current is 11 - 9 = 2 amps. So "di" is 2 amps in the above equation. "d"
is short for "delta", the greek letter that looks like a triangle, which
mathematics uses as the symbol for "the change in".
> am I correct in thinking that the Max on time for the power transistor
> should not be more that 50%?
No. A buck converter can be run at any duty cycle from 0% to 100%.
Consider the PWM controller in an EV. It runs at 0% when you want the
motor completely off, and 100% when you want it full on (essentially
connects the motor directly to the battery).
>> L = V / (di/dt)
>> = 168vdc / (11a-9a)/0.0005sec
>> = 0.042 henries, or 42 millihenries
> that would = 42,000? I better start winding.
0.042 henries = 42 millihenries = 42,000 microhenries. But, you need to
insert your actual numbers. I was just guessing at your AC input
voltage, switching frequency, and DC output current.
> I have a few that I'm playing with, one a 1kw antenna balun,
That one is probably powdered iron. Less than half the bulk of the core
material is iron, and the rest is binder. It won't make a good low
frequency inductor. Try picking it up with a magnet -- you may find it
is hardly magnetic at all.
> some 60 cycle toroids that I can rewind.
They will be wound from a long strip of iron lamination, and won't have
a gap. You'd have to saw a slot in it to use it in a buck converter, and
if you did, it would fall apart.
If you're going to use a low switching frequency (low audio), then use
E-I transformer laminations for your inductor. Stack all the E's and put
your winding on the center leg. Stack all the I's and put a thin paper
shim between the E's and I's as your gap. You can adjust the inductance
by changing the thickness of the gap.
If you're going to use a high switching frequency (above audio), then
use a ferrite core, or molypermalloy toroid core. These will be hard to
find surplus, because you don't have the equipment to measure the core's
magnetic characteristics. It will be like trying to find a resistor that
works in a circuit without an ohmmeter to tell you what it is.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Hi All,
Does anybody know a source for small and/or light
weight phased alternators? I'm thinking about
experimenting with one on my electric bike, but I've
been unable to locate much information on such
devices.
Also, any links to alternators in general would be
helpful.
Thanks,
grant-
__________________________________________________
Do you Yahoo!?
Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
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--- End Message ---
--- Begin Message ---
I don't know what kind they use, but I was watching tv the other day and
heard them mention the alternator on a riding lawn mower. It was pretty
small.
These two links on alternators appeared not too long ago on the list
http://www.mtmscientific.com/alternator.html
http://www.mtmscientific.com/rewind.html
Bobby
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]] On Behalf Of Grant Young
> Sent: Thursday, January 30, 2003 12:11 PM
> To: [EMAIL PROTECTED]
> Subject: light-wieght alternators
>
>
> Hi All,
>
> Does anybody know a source for small and/or light
> weight phased alternators? I'm thinking about
> experimenting with one on my electric bike, but I've
> been unable to locate much information on such
> devices.
>
> Also, any links to alternators in general would be
> helpful.
>
> Thanks,
>
> grant-
>
> __________________________________________________
> Do you Yahoo!?
> Yahoo! Mail Plus - Powerful. Affordable. Sign up now.
> http://mailplus.yahoo.com
>
--- End Message ---
--- Begin Message ---
Thanks to Bob, Lee and David for setting me straight on the Leopard and
Fair Radio chargers. It looks like my Fair Radio will do fine as a
backup.
My Leopard charger is officially for sale.
For that matter, I also have the original Leopard heater. It's just as
crude as the charger. It's an expanded metal screen around a clunky fan
with big aluminum blades that blows over some nichrome wires. It was
mounted in the passenger's footwell. Probably just the thing for former
VW Beetle owners, who long for the days when they could drive in winter
with frozen fingers and their ankles on fire. ;^)
Chris
--- End Message ---
--- Begin Message ---
Anybody going round trip from northern California to Phoenix in the next few
months. Need to send parts (couple of seats, wheels and shocks. Thanks.
Lawrence Rhodes....
--- End Message ---
--- Begin Message ---
I just learned from Optima's website that they have 75Ah yellow tops (D31T &
D31A) and blue top (D31M). Anyone knows anything about them?
Ed Ang
--- End Message ---
--- Begin Message ---
Grant Young wrote:
> Does anybody know a source for small and/or light
> weight phased alternators? I'm thinking about
> experimenting with one on my electric bike, but I've
> been unable to locate much information on such
> devices.
An alternator is just an AC generator; and an AC generator is just an AC
motor being used as a generator. Thus, any small AC motor can be used as
an alternator for your experiments.
Most alternators have a wound field, because that makes it easy to
control the output voltage. Field current times rpm equals output
voltage. Small wound-field AC motors are rare, but they do exist. Look
for surplus "selsyn" servomotors. These are 24vac 3-phase 400 Hz motors
used for various purposes in aircraft.
The majority of AC motors have either induction or PM (permanent
magnet). PM AC motors are easy to use as generators; just spin them and
AC appears on the windings. The frequency and voltage they generate is
directly proportional to rpm. So if the speed varies, you'll need a
converter to step the voltage up or down as needed. Stepper motors are a
common example of PM AC motors that make good generators.
Induction motors are the hardest to use as AC generators. The field (the
rotor) is powered by induction from current flowing in the stator
windings. So you have to get an AC current flowing in the stator
windings first, to get them to start generating. The crudest way to do
this is to connect capacitors to the windings. Spin the motor, and then
pulse the capacitors with DC from some source such as your battery. The
capacitance and inductance of the motor starts an oscillating AC
current, which excites the rotor, and normal generator action begins.
Again, the voltage and frequency generated are directly proportional to
rpm. If you put too heavy a load on it, the capacitive current is not
enough to maintain excitation, and generation abruptly stops.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Also if you have access to some machine tools, you can make a new rotor
using permanent magnets, for an induction motor.
There is some info here.
http://www.otherpower.com/otherpower_experiments_motor_convert.html
Andre' B. [EMAIL PROTECTED]
If something cannot be defined, it does not exist.
Isaac Newton
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
Behalf Of Lee Hart
<< SNIP >>
The majority of AC motors have either induction or PM (permanent
magnet). PM AC motors are easy to use as generators; just spin them and
AC appears on the windings. The frequency and voltage they generate is
directly proportional to rpm. So if the speed varies, you'll need a
converter to step the voltage up or down as needed. Stepper motors are a
common example of PM AC motors that make good generators.
Induction motors are the hardest to use as AC generators. The field (the
rotor) is powered by induction from current flowing in the stator
windings. So you have to get an AC current flowing in the stator
windings first, to get them to start generating. The crudest way to do
this is to connect capacitors to the windings. Spin the motor, and then
pulse the capacitors with DC from some source such as your battery. The
capacitance and inductance of the motor starts an oscillating AC
current, which excites the rotor, and normal generator action begins.
Again, the voltage and frequency generated are directly proportional to
rpm. If you put too heavy a load on it, the capacitive current is not
enough to maintain excitation, and generation abruptly stops.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
They are the long awaited Group 31 Optimas. I am considering purchasing
some. I know of one EVer in the Portland area who bought some recently,
however I don't believe he is not on the list. He is in the EVAlbum.
http://www.austinev.org/evalbum/206.html
I believe he got them for about $170 a piece. That is all I know other then
the datasheets you have probably already downloaded from their website.
damon
From: "Edward Ang" <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
To: <[EMAIL PROTECTED]>
Subject: 75Ah Optima
Date: Thu, 30 Jan 2003 10:38:44 -0800
I just learned from Optima's website that they have 75Ah yellow tops (D31T
&
D31A) and blue top (D31M). Anyone knows anything about them?
Ed Ang
_________________________________________________________________
Add photos to your messages with MSN 8. Get 2 months FREE*.
http://join.msn.com/?page=features/featuredemail
--- End Message ---
--- Begin Message ---
Specs can be found at:
http://www.optimabatteries.com/products/pdf/D31T.pdf
Terminal Configuration: 7/8? stainless steel stud
http://www.optimabatteries.com/products/pdf/D31A.pdf
Terminal Configuration: SAE/BCI automotive.
BR,
Ed T
-----Original Message-----
From: damon henry [mailto:[EMAIL PROTECTED]]
Sent: Thursday, January 30, 2003 12:33 PM
To: [EMAIL PROTECTED]
Subject: Re: 75Ah Optima
They are the long awaited Group 31 Optimas. I am considering purchasing
some. I know of one EVer in the Portland area who bought some recently,
however I don't believe he is not on the list. He is in the EVAlbum.
http://www.austinev.org/evalbum/206.html
I believe he got them for about $170 a piece. That is all I know other then
the datasheets you have probably already downloaded from their website.
damon
>From: "Edward Ang" <[EMAIL PROTECTED]>
>Reply-To: [EMAIL PROTECTED]
>To: <[EMAIL PROTECTED]>
>Subject: 75Ah Optima
>Date: Thu, 30 Jan 2003 10:38:44 -0800
>
>I just learned from Optima's website that they have 75Ah yellow tops (D31T
>&
>D31A) and blue top (D31M). Anyone knows anything about them?
>
>Ed Ang
_________________________________________________________________
Add photos to your messages with MSN 8. Get 2 months FREE*.
http://join.msn.com/?page=features/featuredemail
--- End Message ---
--- Begin Message ---
I have AC PM motors, but they are perhaps too powerful for your
experiments (22 kW rated, about 40 kW max). Excellent choice for a
range extender generator though. Don't know if you consider 22 kg
"light weight".
http://www.metricmind.com/images/acw-80-4a.jpg
Victor
Andre Blanchard wrote:
>
> Also if you have access to some machine tools, you can make a new rotor
> using permanent magnets, for an induction motor.
>
> There is some info here.
> http://www.otherpower.com/otherpower_experiments_motor_convert.html
>
> Andre' B. [EMAIL PROTECTED]
> If something cannot be defined, it does not exist.
> Isaac Newton
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
> Behalf Of Lee Hart
>
> << SNIP >>
>
> The majority of AC motors have either induction or PM (permanent
> magnet). PM AC motors are easy to use as generators; just spin them and
> AC appears on the windings. The frequency and voltage they generate is
> directly proportional to rpm. So if the speed varies, you'll need a
> converter to step the voltage up or down as needed. Stepper motors are a
> common example of PM AC motors that make good generators.
>
> Induction motors are the hardest to use as AC generators. The field (the
> rotor) is powered by induction from current flowing in the stator
> windings. So you have to get an AC current flowing in the stator
> windings first, to get them to start generating. The crudest way to do
> this is to connect capacitors to the windings. Spin the motor, and then
> pulse the capacitors with DC from some source such as your battery. The
> capacitance and inductance of the motor starts an oscillating AC
> current, which excites the rotor, and normal generator action begins.
> Again, the voltage and frequency generated are directly proportional to
> rpm. If you put too heavy a load on it, the capacitive current is not
> enough to maintain excitation, and generation abruptly stops.
> --
> Lee A. Hart Ring the bells that still can ring
> 814 8th Ave. N. Forget your perfect offering
> Sartell, MN 56377 USA There is a crack in everything
> leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
--- Begin Message ---
Anyone know what the AH rating at C/1 would be? Knowing that it's 75
AH at C/20 doesn't give me enough information to know if I should get this
battery.
-- Chris Yoder Smog, Just say NO!
Director, Information Services, DAR Drive electric today.
[EMAIL PROTECTED] http://www.its.caltech.edu/~rcy/
Peace is not the absence of war. Peace is the presence of a system for
resolving conflicts before war becomes necessary. War never creates peace.
- Anonymous
--- End Message ---
--- Begin Message ---
That motor is water or oil cooled?
Do you have physical dimensions?
What type of magnets are used?
Thanks,
Rod
Victor Tikhonov wrote:
I have AC PM motors, but they are perhaps too powerful for your
experiments (22 kW rated, about 40 kW max). Excellent choice for a
range extender generator though. Don't know if you consider 22 kg
"light weight".
http://www.metricmind.com/images/acw-80-4a.jpg
Victor
Andre Blanchard wrote:
Also if you have access to some machine tools, you can make a new rotor
using permanent magnets, for an induction motor.
There is some info here.
http://www.otherpower.com/otherpower_experiments_motor_convert.html
Andre' B. [EMAIL PROTECTED]
If something cannot be defined, it does not exist.
Isaac Newton
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On
Behalf Of Lee Hart
<< SNIP >>
The majority of AC motors have either induction or PM (permanent
magnet). PM AC motors are easy to use as generators; just spin them and
AC appears on the windings. The frequency and voltage they generate is
directly proportional to rpm. So if the speed varies, you'll need a
converter to step the voltage up or down as needed. Stepper motors are a
common example of PM AC motors that make good generators.
Induction motors are the hardest to use as AC generators. The field (the
rotor) is powered by induction from current flowing in the stator
windings. So you have to get an AC current flowing in the stator
windings first, to get them to start generating. The crudest way to do
this is to connect capacitors to the windings. Spin the motor, and then
pulse the capacitors with DC from some source such as your battery. The
capacitance and inductance of the motor starts an oscillating AC
current, which excites the rotor, and normal generator action begins.
Again, the voltage and frequency generated are directly proportional to
rpm. If you put too heavy a load on it, the capacitive current is not
enough to maintain excitation, and generation abruptly stops.
--
Lee A. Hart Ring the bells that still can ring
814 8th Ave. N. Forget your perfect offering
Sartell, MN 56377 USA There is a crack in everything
leeahart_at_earthlink.net That's how the light gets in - Leonard Cohen
--- End Message ---
