EV Digest 2906
Topics covered in this issue include:
1) Re: Battery Box material - a few more details
by "Alan Shedd" <[EMAIL PROTECTED]>
2) Re: Public design charger
by Victor Tikhonov <[EMAIL PROTECTED]>
3) Re: Battery Box material
by "Dave Anderson" <[EMAIL PROTECTED]>
4) Re: Public design charger
by Otmar <[EMAIL PROTECTED]>
5) Vegas Race
by [EMAIL PROTECTED]
6) Re: My Bad-Boy charger
by Lee Hart <[EMAIL PROTECTED]>
7) Re: Ground Fault question
by Lee Hart <[EMAIL PROTECTED]>
8) Re: Public design charger
by "David Chapman" <[EMAIL PROTECTED]>
9) Re: Public design charger
by Sam Uzi <[EMAIL PROTECTED]>
10) Chico EAA 7-12-03 meeting CANCELED !!
by "Chuck Alldrin" <[EMAIL PROTECTED]>
11) Chico EAA 7-12-03 meeting CANCELED !!
by "Chuck Alldrin" <[EMAIL PROTECTED]>
12) Re: used YTs in portland, oregon
by "1sclunn" <[EMAIL PROTECTED]>
13) Re: Public design charger
by "Peri Hartman" <[EMAIL PROTECTED]>
14) Re: Isolated Bad Boy Charger Usage
by Rich Rudman <[EMAIL PROTECTED]>
15) Re: 6 hours of high voltage hammering.
by Rich Rudman <[EMAIL PROTECTED]>
16) Re: Public design charger
by Rich Rudman <[EMAIL PROTECTED]>
17) Re: Public design charger
by Otmar <[EMAIL PROTECTED]>
18) Re: Public design charger
by Otmar <[EMAIL PROTECTED]>
19) Re: Public design charger
by "1sclunn" <[EMAIL PROTECTED]>
20) Re: My Bad-Boy charger
by "Joe Smalley" <[EMAIL PROTECTED]>
21) RE: New EV to go into production
by "Jorg Brown" <[EMAIL PROTECTED]>
22) time delay circuit?
by Paul G <[EMAIL PROTECTED]>
--- Begin Message ---
Others on the list have done a great job, as usual, describing material and
construction options. I doubt I will add much new. Here are a few
considerations.
Many of the high school-built vehicles I have been involved with have used a
variety of battery box designs and materials. Most use steel - either sheet
metal (16-ga) folded in to boxes or welded steel angle to form a frame with
plastic panels and foam insulation to form the sides and bottoms. If not
over-built, the steel frame configuration is fairly light and adequately
strong. The plastic panels improve the look, help protect the batteries and
keep them cleaner. I've used polyethylene sheet stock - it's not structural
but very durable and easy to work (It was also donated). FRP panels sound
nice if you can find or make them. We used 3/4" polystyrene foam - it helps
keep the batteries warm and accommodates small errors in measurement,
fabrication, and battery swelling. Of course steel is subject to corrosion
but like someone suggested, the paint-on bed liner stuff is great.
While aluminum is lighter, it is much more difficult to work with - at the
high school level it generally means finding shop to donate skilled welding
and it cannot be modified or repaired as easily. While aluminum is
adequately strong it is not particularly good for cyclic loading and
repeated flexing that automotive components frequently experience. The
structure must be made more rigid. Connections to the vehicle frame or body
are more important. My Club Car golfcart frame and integral battery rack is
aluminum. It works well but corrosion can be an issue.
I tend to stay away from porous materials like wood. While plywood or
various wood laminates are not affected by battery acid, they can absorb it
and contribute to faults later. Of course for your Li-ion batteries this is
moot.
Good luck. Please keep us posted on your progress.
-Alan
Alan C. Shedd, P.E.
Advisor to Georgia's Electric Vehicle Education Program
(cell) 770-654-0027
[EMAIL PROTECTED]
----- Original Message -----
From: "Mark Fowler" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, July 07, 2003 9:04 AM
Subject: RE: Battery Box material - a few more details
> Thanks for the suggestions and ideas so far :-)
>
> Sorry, I should have been more specific.
>
> The box is for structure.
> The batts are sealed Li-ions, and shouldn't dribble, spit or fart during
normal use (I hope...)
>
> The "box" could be as little as a frame made from angle iron/aluminium
though I think I would prefer to have at least the base and sides enclosed
since it will be open to the road and I'd like to protect the batts from
rocks and other debris.
>
> My current thoughts are for a decent sized aluminium plate as the base,
angle aluminium for the structure, and perhaps plastic for the sides.
>
> Mark
>
--- End Message ---
--- Begin Message ---
Otmar wrote:
>
> I could see people soldering these up themselves and getting together
> in groups to test them.
>
> Thoughts anyone?
As for TTL series ICs, people have different needs but use same
fixed number of ICs to accomplish *their* goals, same approach
may work. Building blocks (outputs directly match inputs)
like
- An isolation (optional stand alone xformer, 60 Hz or HF+circuitry
for common voltages)
- A power stage (stackable for desired output)
- A controller (holds profile which is pluggable EEPROM chip) +
timer(s),
compensation tables, etc.
A user will pick his power stage depending on the mains and desired
power/cost. Input can be (optionally) plugged into output of iso xformer
block.
W/O controller it will only do timed CC/CV.
All the blocks may be physically located in different places,
including outside EV (i.e. iso xformer block can be left in garage).
A user can start with power stage alone and upgrade adding blocks
as (s)he see fit his/her needs and budget.
Other advantage - failure of one block does not render whole charger
unusable (I mean, only this block will need repare/replacement,
the rest of investment keeps working).
Of course, controller interface spec is published so one can
built own controller (CAN based, talking to a custom BMS, whatever
needs may be).
Victor
--- End Message ---
--- Begin Message ---
Aubrey, I relined the steel boxes in my Jet with thin ABS sheet. You can
get ABS sheet from any plastic distributers. In my area, I shop at TAP
Plastics. You can cut ABS sheet easily with tin snips. Then I used contact
cement to glue the sheet to the steel box walls. I used hotmelt glue to
"caulk" the corners. This was a very fast, cheap, and simple operation.
----- Original Message -----
From: "Aubrey Wilder" <[EMAIL PROTECTED]>
To: "EV List" <[EMAIL PROTECTED]>
Sent: Sunday, July 06, 2003 10:07 PM
Subject: Re: Battery Box material
I wouldn't recommend metal. I've got a steel (?) battery box in my Jet 007
and one day I had the charger sitting on top of it. When I closed the front
door, the lid must have bounced down and hit the batteries because I had a
flury of sparks and a small fire that burned the casing on one of my cables.
(The metal contained the fire, at least, and it died pretty quickly.)
In his book, Convert It, Michael Brown recommends painted plywood in a metal
frame, but I would be afraid that if there were a fire it would have a lot
more fuel to work off of. Maybe wood lined with a thin, non-conductive
plastic?
I'm planning on redoing my box soon. I just wish I knew what to use
myself... :)
Aubrey
>> Anyway, what sort of material should I use?
>> Some options I was considering:
>> aluminium plate - how thick? how easy to work with?
>> marine grade MDF - non-conductive, though I don't think the wood look is
>> really what I'm after :-)
>> recycled plastic board - I'm not too sure that this will be strong
enough,
>> but it is nice and non-conductive.
--- End Message ---
--- Begin Message ---
At 6:26 PM -0700 7/7/03, Victor Tikhonov wrote:
> Thoughts anyone?
As for TTL series ICs, people have different needs but use same
fixed number of ICs to accomplish *their* goals, same approach
may work. Building blocks (outputs directly match inputs)
like
- An isolation (optional stand alone xformer, 60 Hz or HF+circuitry
for common voltages)
- A power stage (stackable for desired output)
- A controller (holds profile which is pluggable EEPROM chip) +
timer(s),
compensation tables, etc.
A user will pick his power stage depending on the mains and desired
power/cost. Input can be (optionally) plugged into output of iso xformer
block.
I like the idea of separating out the controller. I see the
controller as a technologically simple thing to make, it can run at
low voltage, makes little heat and therefore could even be a bare PCB
sitting somewhere and not cause safety issues.
As for the separate isolation stage, I guess I feel that low cost non
isolated chargers are well covered by Rich and his PFC series. So I
don't see the value in making a competing device.
I could see a 60hz isolation transformer being utilized in a car, but
then I would just add it to one of rich's chargers.
Some of my goals with this are to make it small and light. And most
importantly to keep the cost down. When I think of many different
modules that can be plugged together I think of high cost. This is
probably because my experience with low volume production shows that
the enclosure and connectors can be a significant part of the cost.
Enclosures get less expensive when you buy more identical ones. Also,
every time you move between modules you have to consider the fact
that someone will wire them incorrectly, so there is more work trying
to protect from that. These reasons are why I was thinking of a unit
that all fit in one enclosure. Using many identical blocks brings the
cost down. As long as the difference for different voltages is only a
few turns on a transformer that you're wiring yourself, then I see it
as very versatile.
Another issue with separating out the different parts is that you may
take an efficiency hit. In the current fed push pull which I'm
thinking of, there is only one switched stage, and it provides PFC,
isolation and regulation. I know of no way to divide it up without
going to a more complicated boost section followed by a forward
converter. This all assumes a high frequency switcher because it is
required for light weight.
W/O controller it will only do timed CC/CV.
That sounds right to me.
All the blocks may be physically located in different places,
including outside EV (i.e. iso xformer block can be left in garage).
Again, that concerns me. I don't see much value in a isolation stage
that is not in the car. I think isolation is most important when you
are charging away from home. That's when strangers are most likely to
be around the car. For example, say I'm charging at the local Costco
and someone asks to see the batteries. I have to warn them not to
touch them, and it's a dangerous time.
A user can start with power stage alone and upgrade adding blocks
as (s)he see fit his/her needs and budget.
This is the idea as I see it, only different in that there would be
no "unsafe" option. Only a lower power option.
Other advantage - failure of one block does not render whole charger
unusable (I mean, only this block will need repare/replacement,
the rest of investment keeps working).
Same with my thoughts on the many small chargers.
Of course, controller interface spec is published so one can
built own controller (CAN based, talking to a custom BMS, whatever
needs may be).
Definitely.
I probably would not vote for CAN. I think it's not well suited to
the isolation requirements of EVs in its' typical hardware
implementation. I think the interface should be low cost and
versatile. I think we have a excellent standard being developed as
the EVIL bus, I'm sure Sheer will document it soon. :-)
Victor
Glad to hear your thoughts!
--
-Otmar-
http://www.CafeElectric.com
Mailto:[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Hey Wayland why don't you shut off your boom box, dust off your Dot-Soon and
get it ready for Vegas in October, Ken and I are planning to charge up
the"Circuit Breaker" to take care of this young Lawless upstart with this Orange Juce
car.
Maybe you could light a fire under Rodrick so he could drag the old Mazda to
Vegas, could be fun.
Time to get these old race cars back on the track again, three months should
be enough time.
Jim.......electricdragster.com
--- End Message ---
--- Begin Message ---
Jim Coate wrote:
> So with all the talk of bad boy chargers... are there tricks with
> capacitors or inductors to *increase* the current? I have a 132 volt
> pack and was playing with a big rectifier as a potential quick charge
> for special use on road trips, but it very quickly drops to <15 amps,
> slower than the smart charger.
A 132vdc pack is a bit high for a bad boy on 120vac. As you have found,
your charging current quickly falls to a very low level.
You can obviously add a buck/boost transformer, autotransformer, or
variac, wired to boost the AC input voltage so your present charger will
work.
You could add a pair of capacitors, wired as a voltage doubler. This
will produce up to 320vdc (enough to fully charge even a 240vdc pack).
The charging current is set by the capacitor values.
--
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 ---
[EMAIL PROTECTED] wrote:
> I have my new pack installed in my Tropica and I've modified
> my charger to remove the connection between AC neutral and
> chassis. Everything works fine until my charger enters finish
> mode and then it trips the GFI. The charger is a buck
> convertor and the only thing different between bulk and
> finish is current. I close a relay which changes the current
> scaling resistors. Actually it just shorts across one. This
> worked before I removed the neutral to ground connection.
First, I'm assuming it's a 120vac charger, which has 1 hot, 1 neutral,
and 1 ground wire, right? A 120vac GFCI works by comparing the AC hot
current to the AC neutral current. If they are equal, then no current is
leaking to ground and it is happy. If the currents aren't the same, the
GFCI presumes there is current flowing to ground, and shuts off.
These GFCI's don't normally use the ground wire, except when you push
the "test" button (which connects a resistor between AC hot and ground).
So, when they connected neutral and ground in the charger, they provided
an alternate path for the neutral current to flow that doesn't need to
go thru the GFCI. I would have expected this to make the GFCI *more*
likely to trip, because some current would flow in the neutral wire,
which unbalances the current sense. Unless, of course, they also CUT the
ground wire so it didn't go to the AC outlet any longer (forcing ground
wire currnt to always be zero). In other words, if they didn't ground
the car frame, but connected it to neutral instead. This would have the
effect of DEFEATING the GFCI!
> I measured the voltage across a 15k resistor placed betwen
> the pack and chassis and got only 18mv.
While charging? AC or DC?
> I checked for shorts between the relay control and chassis
> and found nothing. When I'm in finish mode, the FET control
> pulse width is much narrower to produce the lower current.
Does the frequency stay the same? Or is it a higher frequency *and*
narrower "on" pulse width to get the lower charging current?
> I would think this would produce different harmonics. Can I
> have a connection between the pack and chassis that would
> appear as a capacitor? Its affect would change with frequency
> wouldn't it? Any ideas?
Yes, it would. Batteries sitting in a metal frame do have a significant
amount of capacitance to ground. So do motors and controllers, if they
are connected during charging. And, most GFCIs are designed for normal
consumer products, which (thanks to the FCC) usually have at least some
noise filtering to keep down the amount of high frequency harmonics.
So, it is possible that you have a lot of capacitance to ground, and
high frequency noise from the charger is causing a lot of AC ground
current, and the GFCI is not built to reject such noise and so falsely
trips.
--
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 ---
Otmar,
I have very little idea of exactly what you were saying on the technical
side, but it seems like it was basically: design a simple charger with
flexible or modular design that could be built by most anyone handy with a
soldering iron and following plans. And make it in such a way that
individuals could tailor it/improve it to suit their specific application,
skill level and budget. Sounds Great. For a guy like me, an improved FR
charger. I love my Fair Radio charger, I know its dumb and not the most
efficient charger I own, but its simplicity and flexability make it the one
I tend to use the most. And the price was way cheap. Too bad FR is out and
doesn't expect anymore.
BTW, on the toroids you were talking about, I picked up a couple hundred
ceramic toroid cores the other day, maybe they would be suitable? They are
about 1.42" OD, .875 ID and .600 thick. I could send you a couple if you
would like to experiment. Also if " triple insulated litz wire" is magnet
wire, let me know what diameter. I have quite a few large rolls of different
guages. Regards, David Chapman.
--- End Message ---
--- Begin Message ---
> every time you move between modules you have to consider the fact
> that someone will wire them incorrectly, so there is more work trying
> to protect from that. These reasons are why I was thinking of a unit
> that all fit in one enclosure. Using many identical blocks brings the
> cost down. As long as the difference for different voltages is only a
> few turns on a transformer that you're wiring yourself, then I see it
> as very versatile.
so, at the very least, the transformer(s?) would be readily swappable, if
not completely modular, yes? that implies that the wiring in the rest of
the unit be compatible with the highest-rated transformer to be used, I
presume
(I know, these are bonehead questions but, unfortunately, I'm a bonehead)
> This all assumes a high frequency switcher because it is
> required for light weight.
if I may ask a slightly OT question: I'm presuming that high-frequency
switches cost more, at least ones of useful quality... how fast are good
commercially-available switches these days? ...what kind of per-circuit
cost differences are there between those and, say, 60hz switchs?
--- End Message ---
--- Begin Message ---
This is to inform you that this Saturday's Chico EAA meeting has been
canceled. We were hoping to have the
EcoTrekker team stop by Chico for our meeting. .... this did not work out.
The next meeting will be Saturday August 9th.
Thank you for your understanding.
Chuck Alldrin
530-899-1835
--- End Message ---
--- Begin Message ---
This is to inform you that this Saturday's Chico EAA meeting has been
canceled. We were hoping to have the
EcoTrekker team stop by Chico for our meeting. .... this did not work out.
The next meeting will be Saturday August 9th.
Thank you for your understanding.
Chuck Alldrin
530-899-1835
--- End Message ---
--- Begin Message ---
.
>
> with a bit of help from john wayland ive got the spyder emptied out and
> anxiously awaiting new YTs this friday, woohoo! should have a new set of
> rudman regs to help the new YTs be a little more comfortable too...
>
> --travis
>
>
As I remember you where thinking about cramming golf cart bats in there .
Glad to hear your going with the YT , If thats the car i remember it looked
like a nice conversion job.Now is that 2 x 120 or 240 ?
>
--- End Message ---
--- Begin Message ---
I keep wondering... if one were to design a controller that's also intended
to be a charger, wouldn't there be some savings of combining the regen
circuit and the charging circuit? Both need to handle high voltage and
current. If you're running an A.C. motor, it seems half the battle is
already won. But, I think a simple rectifier could hook onto the front of a
D.C. system and still let the controller do all the charging work.
Peri Hartman
----- Original Message -----
From: "Otmar" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, July 07, 2003 8:49 PM
Subject: Re: Public design charger
> At 6:26 PM -0700 7/7/03, Victor Tikhonov wrote:
>
> > > Thoughts anyone?
> >
> >As for TTL series ICs, people have different needs but use same
> >fixed number of ICs to accomplish *their* goals, same approach
> >may work. Building blocks (outputs directly match inputs)
> >like
> >
> >- An isolation (optional stand alone xformer, 60 Hz or HF+circuitry
> > for common voltages)
> >- A power stage (stackable for desired output)
> >- A controller (holds profile which is pluggable EEPROM chip) +
> >timer(s),
> > compensation tables, etc.
> >
> >A user will pick his power stage depending on the mains and desired
> >power/cost. Input can be (optionally) plugged into output of iso xformer
> >block.
>
> I like the idea of separating out the controller. I see the
> controller as a technologically simple thing to make, it can run at
> low voltage, makes little heat and therefore could even be a bare PCB
> sitting somewhere and not cause safety issues.
>
> As for the separate isolation stage, I guess I feel that low cost non
> isolated chargers are well covered by Rich and his PFC series. So I
> don't see the value in making a competing device.
> I could see a 60hz isolation transformer being utilized in a car, but
> then I would just add it to one of rich's chargers.
>
> Some of my goals with this are to make it small and light. And most
> importantly to keep the cost down. When I think of many different
> modules that can be plugged together I think of high cost. This is
> probably because my experience with low volume production shows that
> the enclosure and connectors can be a significant part of the cost.
> Enclosures get less expensive when you buy more identical ones. Also,
> every time you move between modules you have to consider the fact
> that someone will wire them incorrectly, so there is more work trying
> to protect from that. These reasons are why I was thinking of a unit
> that all fit in one enclosure. Using many identical blocks brings the
> cost down. As long as the difference for different voltages is only a
> few turns on a transformer that you're wiring yourself, then I see it
> as very versatile.
>
> Another issue with separating out the different parts is that you may
> take an efficiency hit. In the current fed push pull which I'm
> thinking of, there is only one switched stage, and it provides PFC,
> isolation and regulation. I know of no way to divide it up without
> going to a more complicated boost section followed by a forward
> converter. This all assumes a high frequency switcher because it is
> required for light weight.
>
> >W/O controller it will only do timed CC/CV.
>
> That sounds right to me.
>
> >All the blocks may be physically located in different places,
> >including outside EV (i.e. iso xformer block can be left in garage).
>
> Again, that concerns me. I don't see much value in a isolation stage
> that is not in the car. I think isolation is most important when you
> are charging away from home. That's when strangers are most likely to
> be around the car. For example, say I'm charging at the local Costco
> and someone asks to see the batteries. I have to warn them not to
> touch them, and it's a dangerous time.
>
> >A user can start with power stage alone and upgrade adding blocks
> >as (s)he see fit his/her needs and budget.
>
> This is the idea as I see it, only different in that there would be
> no "unsafe" option. Only a lower power option.
>
> >Other advantage - failure of one block does not render whole charger
> >unusable (I mean, only this block will need repare/replacement,
> >the rest of investment keeps working).
>
> Same with my thoughts on the many small chargers.
>
> >Of course, controller interface spec is published so one can
> >built own controller (CAN based, talking to a custom BMS, whatever
> >needs may be).
>
> Definitely.
> I probably would not vote for CAN. I think it's not well suited to
> the isolation requirements of EVs in its' typical hardware
> implementation. I think the interface should be low cost and
> versatile. I think we have a excellent standard being developed as
> the EVIL bus, I'm sure Sheer will document it soon. :-)
>
> >Victor
>
> Glad to hear your thoughts!
> --
> -Otmar-
> http://www.CafeElectric.com
> Mailto:[EMAIL PROTECTED]
>
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
>
> > > > Tom Hudson suggested a open source charger, I assume he means
> > > > isolated (if I read his intentions correctly). I'd be happy to
> > > > contribute a little time to that project, especially if it fit's the
> > > > specs I want (32A input, PFC, isolated, smart, inexpensive etc) If
> > > > there is interest I'll set up a mailing list for it, or we could just
> > > > do it on evtech.
> > > >
> > > > --
> > > > -Otmar-
>
> What's the key words in above statement?
> "If it fits the specs I want".
>
> Trouble is everyone wants different specs.
>
> Also, I'm afraid, selling such a charger for the cost (if it ever
> gets built) will not save much money. The cost includes creators' time.
>
> If this time is 100% donated, then the cost of the charger is just
> its hardware and manufacturing cost.
>
> Despite my wish for such a project to succeed I think universal
> fits all charger is not possible for the same reason as universal
> fits all car. There is no such thing.
>
> It would be more-less possible if 99% of the people will agree
> to only use 156V single string group 27 Optimas (no deviations
> allowed), or something like that.
>
> I think the crowd is more diverse and ambitious than that.
>
> I'll be in minority (I always am, doesn't bother me), but can tell
> right away I wouldn't want such a charger.
>
> This doesn't mean idea is bad. I just don't see it being realistic.
> Hope I'm wrong.
>
> Victor
Ummm I thought the Manzanita PFC chargers WERE the EV list one does all
charger. Where do you think I got all the ideas and all the customers??
Joe said it could be done, and I said lets do it!
You all need to think about this, and why a PFC20 is $1500, and has no
micro or comm port, or display. They add alot of time and cost, and are
simply NOT needed to get the job done(for most).
I echo Victor's statments, you guys don't know the costs and processes
that go into hardware design, and the monumental efforts to get just 3
Bit heads to agree on a simple communications port protocol. Witness the
Evil buss and Sheer's atempts to impliment it in a timely manner.
I am spreading my self thin trying to make as many happy as possible. I
am not taking %100 of the market, what am I doing wrong?
With all the goodies that you all wish to have, your charger will come
in at about $3000, and not much profit. Strip it back to a bare bones
power processor, and a on off switch, and now you have a product in your
cost ball park. Add in as much control logic as you can afford, and you
will be right where I am right now.
Oh yea dumping Iso will save you about $200. THAT's a big chunk of a
$1000 charger. Much nore if you drop the cost line at $750.
Most of us on this list can wack out a Basic program that voltage
regulates and current limits some sort of a switch. That's the easy
part.
Iso is brutaly heavy or brutally complicated(HF)
PFC is a mess unless you go active, or really heavy.
Control is a matter of what is wanted.
The enclosure is spendy and makes or breaks a Professional product.
Just remember I just spent the last 24 months doing just this.
I can answer most of your questions with experience. The rest I am still
learning about.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
>
> Rich Rudman wrote:
> >
> > Tom Hudson wrote:
> > >
> > > >
> >
> > > You shouldn't have to pay $5000 for a battery charger just to get a safe,
> > > reliable charge. Anyone out there interested in working on this?
> >
> > I do it all with out a micro, and hand you 2500 watt from 120 and 5000
> > watts from 240, and this for $1500.
> > This is a long cry from $5000.
>
> I'm curious to see this $5000 charger. I have top of the line ones with
> micros and all bells and whistles for a bit over $3k.
>
> So which chargers are you talking about (unless you just make up numbers
> to express your unsatisfaction)?
>
> Victor
Umm Victor I did NOT come up with the $5K. I know your nice kickass
charger is 3000 plus.
Not my numbers.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
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Otmar wrote:
>
> At 3:02 PM -0700 7/7/03, Victor Tikhonov wrote:
>
> > > > > Tom Hudson suggested a open source charger, I assume he means
> >> > > isolated (if I read his intentions correctly). I'd be happy to
> >> > > contribute a little time to that project, especially if it fit's the
> >> > > specs I want (32A input, PFC, isolated, smart, inexpensive etc) If
> >> > > there is interest I'll set up a mailing list for it, or we could just
> >> > > do it on evtech.
> >> > >
> >> > > --
> >> > > -Otmar-
> >
> >What's the key words in above statement?
> >"If it fits the specs I want".
> >
> >Trouble is everyone wants different specs.
>
> Good point Victor.
>
> >Also, I'm afraid, selling such a charger for the cost (if it ever
> >gets built) will not save much money. The cost includes creators' time.
>
> That is true too. But if a bunch of interested parties donate
> development time, as well as documentation and sourcing time and
> funds (for group buys), then people could possibly build their own.
> It's tough, I know, especially with power electronics. But if most of
> it comes from Digikey it might just work. :-)
>
> >If this time is 100% donated, then the cost of the charger is just
> >its hardware and manufacturing cost.
> >
> >Despite my wish for such a project to succeed I think universal
> >fits all charger is not possible for the same reason as universal
> >fits all car. There is no such thing.
> >
> >It would be more-less possible if 99% of the people will agree
> >to only use 156V single string group 27 Optimas (no deviations
> >allowed), or something like that.
> >
> >I think the crowd is more diverse and ambitious than that.
> >
> >I'll be in minority (I always am, doesn't bother me), but can tell
> >right away I wouldn't want such a charger.
> >
> >This doesn't mean idea is bad. I just don't see it being realistic.
> >Hope I'm wrong.
>
> I went for a hike yesterday. I've also been working on a power supply
> for too many months now, so I'm somewhat familiar with the issues
> around them.
> I usually do my best systems engineering when hiking. I don't know if
> this idea is good, but I'll put it out there. I've included my choice
> of the ideas that I've heard, plus my own thoughts.
>
> Here's what I'm thinking for a public project charger:
>
> 5 amps input (~1000 watts at 220V) per module.
> Reason: it's easy to do with PCB traces and cheap heat sinks.
> No need to parallel many power devices or bend up buss bars. Target
> power parts SPP06N80C3 at about $1 each. Output current 11A or less,
> easy with small parts.
>
> Up to 2 modules per case. 3" square case about 10" long. Air cooled
> with a 3" fan on one end. (modular like Todd chargers, but with a
> control board and temp sensors on each sub section)
>
> Modules could be configured for different voltages by changing the
> transformer windings internally. 1 module could be configured from
> 96V to 156V nominal. Modules would then be put in series or parallel
> for more voltage or current.
> A high voltage AC car would need 3 or 6 modules to function. Lower
> voltage cars could run on any number in parallel.
>
> Topology could be a current fed push pull running at 68 khz. Two
> switches, one inductor and one transformer give a PFC isolated
> supply. Advantage is very compact topology and pretty efficient,
> Drawback is odd control and high ripple current output caps required.
>
> Magnetics could be hand wound torroids, like what you see in car
> stereo amps. They are easy to get in low quantity. (I haven't checked
> the size of these, I'm assuming they'd fit in the 3" case) It would
> probably require a group buy of triple insulated litz wire for the
> output. (assuming we want UL style isolation).
>
> Base design could allow 60hz ripple current to go on to the
> batteries, added filter (more cost) could smooth that out for those
> who care (those with high impedance batteries).
>
> The charger processor would know the input current, input voltage,
> output voltage and at least one internal temperature. It could
> estimate the output current (for protection) if no master controller
> was watching it for the charge algorithm.
>
> Algorithm control would be by EVIL bus. This off loads the charge
> profiles to another processor which could control any number of these
> at the same time (and do battery monitoring). A very simple single
> node controller could be made for those who are not yet using EVIL
> bus, which at the moment is pretty much everyone. :-)
>
> I could see people soldering these up themselves and getting together
> in groups to test them.
>
> Thoughts anyone?
>
> --
> -Otmar-
> http://www.CafeElectric.com
> Mailto:[EMAIL PROTECTED]
Humm, NOT the way I would go... but very interesting, and doable.
I can source Roids in volume, or just turn you all onto Micrometals.com
I use a 4 inch core -34 stuff good to 50Khz, nice soft roll off when
saturated.... ;)
I don't like the narrow range outputs. But that's me.
don't worry about out put ripple PbLa look just like electrolytics
anyways. Use enough ripple cap to keep the output silicon alive.
And what chip set are you using for PFC control on the front end??? do
you have Buck control on the aft end???
Can the general EV list deal with the control chip set??
Evil buss, Ummm we are both poles in a multi pole filter in that one.
--
Rich Rudman
Manzanita Micro
www.manzanitamicro.com
1-360-297-7383,Cell 1-360-620-6266
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At 9:03 PM -0700 7/7/03, David Chapman wrote:
Otmar,
I have very little idea of exactly what you were saying on the technical
side, but it seems like it was basically: design a simple charger with
flexible or modular design that could be built by most anyone handy with a
soldering iron and following plans. And make it in such a way that
individuals could tailor it/improve it to suit their specific application,
skill level and budget.
That's the idea.
Sounds Great. For a guy like me, an improved FR
charger. I love my Fair Radio charger, I know its dumb and not the most
efficient charger I own, but its simplicity and flexability make it the one
I tend to use the most. And the price was way cheap. Too bad FR is out and
doesn't expect anymore.
BTW, on the toroids you were talking about, I picked up a couple hundred
ceramic toroid cores the other day, maybe they would be suitable? They are
about 1.42" OD, .875 ID and .600 thick. I could send you a couple if you
would like to experiment.
I admit, transformer design is one of my weak points. They sound a
bit small to me, but if we knew the specification of the material we
could punch some numbers in and see how they do. As I understand it
there are hundreds of types of torroids, both ferrite and powdered
metal. I think we are looking for ferrite in this case, though the
powdered meal may be better for the boost inductor.
I'm not set up to measure the characteristics of cores, but maybe
someone else is?
Also if " triple insulated litz wire" is magnet
wire, let me know what diameter. I have quite a few large rolls of different
guages. Regards, David Chapman.
It's a special magnet wire. It's made of many strands of small magnet
wire, and then has two more layers of insulation on it. I don't think
it's very common, but it can be gotten...
--
-Otmar-
http://www.CafeElectric.com
Mailto:[EMAIL PROTECTED]
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At 7:02 PM -0700 7/7/03, Sam Uzi wrote:
> every time you move between modules you have to consider the fact
that someone will wire them incorrectly, so there is more work trying
to protect from that. These reasons are why I was thinking of a unit
that all fit in one enclosure. Using many identical blocks brings the
cost down. As long as the difference for different voltages is only a
few turns on a transformer that you're wiring yourself, then I see it
as very versatile.
so, at the very least, the transformer(s?) would be readily swappable, if
not completely modular, yes? that implies that the wiring in the rest of
the unit be compatible with the highest-rated transformer to be used, I
presume
That is correct. If we are winding the transformers ourselves, then
it's not tough to leave a few turns off a output winding to lower the
output voltage. This does assume that the wire can tale the current
required for the lowest voltage rating.
> This all assumes a high frequency switcher because it is
required for light weight.
if I may ask a slightly OT question: I'm presuming that high-frequency
switches cost more, at least ones of useful quality... how fast are good
commercially-available switches these days? ...what kind of per-circuit
cost differences are there between those and, say, 60hz switchs?
I don't know the answer to that. If I look at Lester golf car
chargers, it seems that they are only a little less expensive that a
equivalent switcher. (and much heavier) But it's hard to know which
numbers to compare. I don't have equivalent costs for each.
--
-Otmar-
http://www.CafeElectric.com
Mailto:[EMAIL PROTECTED]
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>
> I could see people soldering these up themselves and getting together
> in groups to test them.
sounds like a neat project and a chance to learn a little , I hope I can
keep up > /.
count me in
Steve Clunn
> Thoughts anyone?
>
> --
> -Otmar-
> http://www.CafeElectric.com
> Mailto:[EMAIL PROTECTED]
>
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You will need a sensor to tell the charger when to quit charging.
If you don't have a turn off mechanism, you will fry your batteries the
first time you forget to turn the charger off.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, July 07, 2003 6:21 PM
Subject: Re: My Bad-Boy charger
> Jim Coate wrote:
> > So with all the talk of bad boy chargers... are there tricks with
> > capacitors or inductors to *increase* the current? I have a 132 volt
> > pack and was playing with a big rectifier as a potential quick charge
> > for special use on road trips, but it very quickly drops to <15 amps,
> > slower than the smart charger.
>
> A 132vdc pack is a bit high for a bad boy on 120vac. As you have found,
> your charging current quickly falls to a very low level.
>
> You can obviously add a buck/boost transformer, autotransformer, or
> variac, wired to boost the AC input voltage so your present charger will
> work.
>
> You could add a pair of capacitors, wired as a voltage doubler. This
> will produce up to 320vdc (enough to fully charge even a 240vdc pack).
> The charging current is set by the capacitor values.
> --
> 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
>
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I don't mean to be a downer, but my eyes just glaze over at people's new
electric car projects. The hurdles to making a full-on electric car are
enormous - including lots of regulatory hurdles, red ink, etc. Just ask
the AC Propulsion people why the tZero hasn't made it yet. Or the
tropica folk. Or the 3-wheeler...
Biggest thing is, when someone else builds it, they not only lock you
into a style of car (sport car, sedan, truck, 4x4, whatever), they also
lock you into a type of propulsion, and a battery technology.
I'm sick of being forced to pick between the two extremes of expensive
pre-built electrics whose manufacturers are going broke, and inexpensive
old gassers in need of lots of conversion labor.
I don't want an electric vehicle anymore. Right now what I want is a
cheap, LIGHT, chassis with a big, low-center-of-gravity battery box.
Give me a speedometer, ammeter, and voltmeter, make it rear-wheel drive,
and give me a way to pick my own gear ratio, my own motor, my own
controller, my own battery.
Surely, someone...
jorg
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Brad Waddell
Sent: Saturday, July 05, 2003 11:43 AM
To: [EMAIL PROTECTED]
Subject: New EV to go into production
Not sure if you have all seen this new page yet, still under
construction.
Another ambitious project that hopefully will see the road!
http://www.universalelectricvehicle.com/
brad
Brad Waddell ** FLEXquarters.com LLC ** voice-mail/fax: 602-532-7019
Postal: 6965 El Camino Real Ste 105 #488 Carlsbad CA 92009 USA
QODBC Driver for Quickbooks - Unleash your data at www.qodbc.com
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This circuit is designed to provide an output that is about 25
milliseconds delayed from the input. I am hoping that 25ms is enuf
time for the bi-stable relay on the input side to disconnect the
closed contacts (is that realistic?). If that is not enuf time its
pretty easy to change by changing the value of C1.
(view in monospace font)
+ in---------------------
| | |R | |
| | \2 SCR V \R
D1 V \ / - /4
- / \ \D2 /| \
| R\ |--|<--/ | |
| 1| | \ | | |
| | | R\ | = C2
| | = C1 3/ | |
| | | \ | |
| | | D1 | | |
-gnd--------->|------------+ out
D1 silicon diode to protect against relay coils connected to both
the input and output
R1 510 ohms, to discharge C1, 1/2 watt
R2 5.1k ohms, to charge C1, 1/4 watt
C1 6.8uf, with R2 about 20ms for the top to reach 6 volts
D2 6.0 volt zener diode, to gate of SCR, DO-35 package, 1/2 watt
R3 100k ohms, to hold gate to ground when off, 1/4 watt
SCR sensitive gate SCR, 1.5amp TO-92 package, max gate current to
turn on is 200uf (about 300uf at 5F), gate current shouldn't exceed
10ma
R4 15 ohms, part of SCR snubber, 1/4 watt
C2 0.01uf, part of SCR snubber
There are people out there that know alot more about circuit design
than me, I'm just a hack. What is right or wrong with this design?
Anyway, the purpose of this design is to use 3 SPDT bi-stable relays
to operate my headlights and neon lights on my Buggy using the start
position of the ignition switch. All off, headlights on, headlights
and neon on, neon on, all off again. The idea is to get rid of the 2
switches under the dash. There is likely a better way to do this, but
I'm no EE :-)
Thanx,
Neon
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