EV Digest 6075
Topics covered in this issue include:
1) Re: Non Traditional EV Drivetrains
by "Stefan T. Peters" <[EMAIL PROTECTED]>
2) Re: I can build your controller
by Lee Hart <[EMAIL PROTECTED]>
3) Re: 2X Alltrax = Curtis ?
by Lee Hart <[EMAIL PROTECTED]>
4) Re: EV controllers? the 4th option...
by Lee Hart <[EMAIL PROTECTED]>
5) Re: I can build your controller
by Lee Hart <[EMAIL PROTECTED]>
6) Re: brrr cold zero F today
by Lee Hart <[EMAIL PROTECTED]>
7) Re: EV controllers? the 4th option...
by Lee Hart <[EMAIL PROTECTED]>
8) Re: Avcon problem
by Nick Austin <[EMAIL PROTECTED]>
9) Re: I can build your controller
by "Bob Rice" <[EMAIL PROTECTED]>
10) Chinese EV's WAS Re: Chinese controllers
by "Bob Rice" <[EMAIL PROTECTED]>
11) Re: I can build your controller
by "Rich Rudman" <[EMAIL PROTECTED]>
12) Re: I can build your controller
by "Roderick Wilde" <[EMAIL PROTECTED]>
13) Re: I can build your controller, off topic
by "Roderick Wilde" <[EMAIL PROTECTED]>
14) Re: I can build your controller
by "Osmo S." <[EMAIL PROTECTED]>
15) unsubscribe
by "Bob Brooks" <[EMAIL PROTECTED]>
16) Re: EV controllers? the 4th option...
by "Arthur W. Matteson" <[EMAIL PROTECTED]>
17) Re: 2X Alltrax = Curtis ?
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
18) Re: brrr cold zero F today
by mike golub <[EMAIL PROTECTED]>
19) Navitas controller, was:Re: I can build your controller
by James Massey <[EMAIL PROTECTED]>
20) Re: brrr cold zero F today
by mike golub <[EMAIL PROTECTED]>
21) Re: 2X Alltrax = Curtis ?
by Jeff Shanab <[EMAIL PROTECTED]>
22) Re: I can build your controller, off topic
by "torich1" <[EMAIL PROTECTED]>
--- Begin Message ---
GWMobile wrote:
Anyone done a hydraulic link?
Hydraulic hoses make motor placement unrestricted.
You mean a hydraulic drive?
To transmit 100HP, you need a 100HP hydraulic motor, and you need a pump
capable of feeding it (around 60-80 GPM at 3000PSI, depending on output RPM)
Now hydraulic motors typically have low RPM and high torque (the faster
ones torque peak at 1800RPM). So no need for the tranny. But you have a
~85% efficiency in the pump *and* the motor. That gives you some serious
losses. I believe this (and the safety issue - I would rather play
around with 300VDC then 3000PSI anyday!) is why we don't see hydraulic
drives in more vehicles already...
~ Peanut Gallery ~
--- End Message ---
--- Begin Message ---
Rocketjosh wrote:
I have much respect for the others making controllers. I have one
problem, however -- I can't get a quality controller at a reasonable
price nor a reasonable time-frame. I see an opportunity to provide
a more reliable source of quality controllers.
I ask for some basic information (BOM, schematic, etc) is to get an
INITIAL estimate of cost.
Otmar spent a lot of time and money designing his controller, and he is
selling it. Naturally, he would not want to give away that design. If
you are serious about producing it, you need to work out a price with
him to license the design.
Rich doesn't have a controller ready for production. He could create
one, but that costs time and money, and takes him away from things he'd
rather be doing. Again, you'd need to pay him to do the work.
Quite a number of controllers are documented in various books and
manufacturer's application notes. Any of them should be suitable to get
a rough idea of what it would cost. Just be aware that most of these
designs are only partially worked out -- the designer took them just far
enough along to get one controller that worked for a short time; they
aren't perfected well enough to produce and sell as-is.
Or, you can take the time-tested approach of reverse-engineering; buy a
controller you like, tear it apart, and make your own parts list,
schematics, etc. Then "clone" it to produce your own version.
Overall, I suspect that if there were money to be made in EV
controllers, the Chinese would already have cloned several of the US
controllers.
--
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 ---
Steve Condie wrote:
I asked Alltrax if I could do this a year or two ago. They said no,
because the controller would "see" more than 72 volts.
There was a discussion on this a year or two ago on the EV list, and I
posted some schematics on how to do it. Basically, you can wire it so
the controller never "sees" more than 72v, yet have a 144v pack. It uses
contactors to rearrange the circuit so the controller takes you from
0-72v, then you switch the contactors, and the controller takes you from
72-144v.
--
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 ---
Lee Hart wrote:
Or two of these (one for pullup, one for pulldown):
http://www.ixys.net/l410.pdf (200v, 580a)
Stefan T. Peters wrote:
Yup... at $261 each, two modules breaks about even with ten ISOTOPs
at $42 each.
Yes; modules are more expensive than buying a bucket of cheap parts and
wiring them all in parallel yourself. But it's a lot easier, and you are
more likely to get something that actually works and is reliable.
What's the max pulse amperage of the modules, it doesn't
list that in the spec.
In a motor controller, peak ratings are usually not relevant. You can't
operate anywhere near the peak voltage or current, because the module
would die.
The real-world values that matter are usually derived from its thermal
performance. How much current can it carry at a particular baseplate
temmperature? What size heatsink does it take to achieve this
temperature in your environment?
For example, the advertising spec at the top of the page says "Id=580
amps" and "Rds(on)=3.8 mohms" (both at 25 deg.C case temperature). This
causes a voltage drop Vds = 580a x 0.0038 ohms = 2.2v and a power
dissipation in the module Pd = 2.2v x 580a = 1275 watts.
Now, if the case is at 25 deg.C, how hot is the transistor junction
inside? Way down at the bottom of the page, in tiny letters, they say
the thermal resistance from junction to case Rth(JC) = 0.05 deg.C/watt.
So at 1275 watts, the junction is 0.05 x 1275w = 64 deg.C hotter -- a 25
deg.C case means a 89 deg.C junction temperature.
But Rds goes up with temperature. It won't be 3.8 milliohms when the
junction is at 89 deg.C. Rds will be higher, like 4-5 mohms. Good data
sheets will give you curves for Rds vs. temperature.
Also, no practical heatsink can hold the case at 25 deg.C with 1275
watts of heat being dumped into it. Realistically, a very big heatsink
might have a thermal resistance of 0.1 deg.C/watt. The thermal
resistance from junction to air is thus 0.05 (module, junction to case)
+ 0.1 (heatsink, case to air) = 0.15 deg.C/watt.
And, it might be a hot day in Arizona, where the ambient air temperature
is 122 deg.F = 50 deg.C. You can't run the junction over 100 deg.C
without reliability problems. So 50 deg.C is the biggest temperature
difference you can allow between junction and ambient.
So, the most the module can dissipate is Pd = 50w / 0.15 deg.c/w = 333
watts. With an Rds of 4.5 mohms (hot), that is only 272 amps (because P
= I^2 R, 333w = 272^2 x 0.0045 ohm).
Thus from a thermal standpoint, this module can only carry about 272
amps continuously (though the peak can be higher).
What's pullup, pulldown?
A buck PWM controller needs two power semiconductors; one to switch the
motor to the pack voltage (pullup), and one to switch the motor to zero
volts (pulldown). For a series motor, one is a transistor and the other
is a diode.
--
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:
Josh, since I am not an EE I cannot offer much except my vote of
support. Notwithstanding Dave's concerns about China, you might
find the list a little negative at times, finding problems rather
than solutions. It might be a bit of an uphill struggle. However,
persevere and you should be rewarded with customers who simply
want to get their conversions done and on the road.
I am an EE, and might be able to offer a bit of insight. EEs tend to
focus on problems first, and solutions second. If you ask a question, an
engineer is likely to start out by listing all the prior history, what
went wrong, why you can't do it, etc. It can be a depressing list.
But just wait... after he has run down this list, a good engineer will
start down the list of *solutions* to the problem. He'll list the ideas
that haven't been tried yet, or were tried but the implementation was
faulty, or even start inventing new solutions.
Engineers don't give up. They assume every problem has a solution; in
fact, they all have more than one solution. They'll keep "worrying" the
problem until they come up with an answer.
So, don't give up the game too soon. It's like chess; when it's your
move, you look at the board. The first moves you see are the easy, but
bad ones. You have to keep looking to find the promising moves. But then
you need to look ahead -- if I do this, what will he do? That will make
you discard many more promising moves. All your data so far is negative;
this won't work, that's a bad one, etc. But eventually, you will find a
truly good move. It won't be perfect because you can't see that far
ahead. But it keeps you in the game!
--
"An engineer can tell you if it will work *before* you build it.
Any damned fool can tell you *after* it's built."
-- Charles Proteus Steinmetz
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
mike golub wrote:
Questions
1. Is it OK to use styrofoam to insulate the cab? The
stuff is flammable, but I wonder what type of fire
danger there is?
Styrafoam is a good insulator, and cheap. Yes, it burns; but 99% of the
plastics and fabrics (and oil and gasoline) used in cars also burn. Very
little attention is given to fire safety in cars.
The problems with styrafoam are usually in other areas. It is bad
environmentally, because of the chemicals used to make it. It is
attacked by almost any hydrocarbon; gasoline, oil, and most glues and
adhesives will disolve it. It is mechanically weak, and easily gets beat
up. It "squeaks" if there is any movement.
But if these concerns are ok, by all means, use it.
2- If I add the second element. Do I mount it so the
air goes through both or do I just mount in the same
plane as the other element. I wonder because if I
added a third one I'd run out of space?
The air passing through the element tends to have a certain temperature
rise. The amount depends on the voltage and airflow. You can get
temperature rises on the order of 30-60 deg.F.
Suppose you set it up for a 40 deg.F rise. When it is 60 deg.F outside,
you get 100 deg.F air (great). When it is 0 deg.F outside, you get 40
deg.F air (not so great -- no "heat" and it can barely defog the
windshield).
You can reduce the airflow to get a higher temperature rise; but you
also get less total heat by doing this. That's because the hotter the
element gets, the less current it draws and the less heat it makes.
If you live in a place that never gets particularly cold, put the two
elements side-by-side. If you live in a place that gets very cold (like
Minnesota), put the elements one in front of the other, so one preheats
the air by (say) 40 deg.F, and the second one heats it another 40 deg.F.
Now you can get 80 deg.F air when it is 0 deg.F outside.
--
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 ---
Arthur W. Matteson wrote:
I know some have been confused about why one would choose a module for a
DC controller that has "wasted" parts. This seems counter-intuitive.
The reason my [quickly progressing] semi-open-source DC motor controller
uses half-bridge modules is the following:
- Stray inductance! -
Good point. Other good points are thermal performance, isolation, and
current sharing. Modules are built to minimize these problems. If you
"build your own" module with dozens of parallel devices, you have to
solve all these problems yourself.
[synchronous rectification] doesn't work with IGBTs. Even the best
of them have twice the voltage drop of a good diode.
* A single tear falls from Arthur's face... *
Sorry Arthur; I didn't mean to make you cry!
I know; there are lots of reasons why you don't use IGBTs for
synchronous rectifiers; voltage drop is just the most obvious one.
MOSFETs happen to make pretty good synchronous rectifiers.
--
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 ---
On Sat, Oct 28, 2006 at 01:43:57PM -0400, [EMAIL PROTECTED] wrote:
> I did not try it on the S-10 because it pulls 6.6 kW and the Avcon is 5.0 kW
Were you using one of the derated USPS units?
Most avcons are 32A off 240V == 7.6KW
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "Stefan T. Peters" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, October 28, 2006 1:29 AM
Subject: Re: I can build your controller
> Lawrence Rhodes wrote:
> > .... David there is simply nothing
> > to be had but Curtis, Zapi & Altrax for the most part.
> On a related note, anyone try the Navitas TSE 96v/600A Controller yet?
>
> http://navitastechnologies.com/PDF/TSE600-96_Brochure.pdf
>
> Just curious...
>
> Hi Guyz;
Boy! That looks like just what I could use in my 90 volt Sentra, the one
with the busted Cursit! Try them on Monday as they are closed on Sat.They
say that the build locomotive controllers?That's what our led loco's
need!It's a Canadian outfit, so we in US have a exchange advantage?
Seeya
Bob
>
> --
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>
>
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "JS" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, October 27, 2006 7:32 PM
Subject: Chinese controllers
Snip a bit
> While I try to buy American, and resent much of the Chinese competition,
> Hi EVerybody;
> If we cannot get the U.S. auto makers interested in EV
> maybe China will.
John in Sylmar said.
And I know that an EV-1 and S-10 went to China, as well as AC Propulsion
stuff, too. As we in America give the store away and pay them(The Chinese)
to take it!So I won't be surprised that the Chinese hit our shores with
EV's. Maybe the Panic Sonic 95 NiMH battery, too? As Chinese don't pay much
attention to patent laws. But I'll bet if WE "borrowed" one of THEIR
patents, here, and made money on it. They would howl about it<G>!It COULD
happen, a Thunder Sky Roadster, made in Hartford CT?A Sacred Sun Schoolbus?
Whimsical Chinese product names are fun, anyhow.
Anyhow You can rest assured that the Chinese have reverse engineered the
above stuff, by now?I'll bet they EVen copy the mail here? Hi China!! Ha Bu
How??(That's How ar ya? in Chinese) Copy all ya like, hit reply and bring it
on back!
Nations aside SOMEBODY'S got to do it!10 Billion of Oil Profits( Hexxon)
say " Not Here!"
>
> John in Sylmar, CA
> An' Bob in Killingworth, CT
>
>
> --
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> Checked by AVG Free Edition.
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>
>
--- End Message ---
--- Begin Message ---
First it to design a power stage and case that can be assembled in about 15
minutes or less.
No great tricks.. good engineering and much thought to packaging and
assembly.
Then you can have $20 a hour "Mericans" do the labor for you. And not loose
your lunch money doing it.
Both DCP and Cafe Electric have and had a Night mare of assembly procedures
to make their power stage.
I won't be making that mistake. These controller have to go together quick
and fast and right.
Water Jet copper machining is getting down right cheap compared to about 10
years ago.
I know enclosures..well my Dad does lets put it that way.
And Again folks... I will NOT be subbing out assembly and production to
China. It's against my business principles. I get components and circuit
boards from off shore but the final is Going to be
MADE IN USA.
May be Oriental or Hispanic Citizens of the US of A.
On this point there is no discussion.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Rod Hower" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, October 27, 2006 3:55 PM
Subject: Re: I can build your controller
> One more curveball to throw in. Rich Rudmans charger
> or proposed control with analog only (no MCU) could be
> easily duplicated since there is no proprietary
> software. I guess if the market gets big enough this
> is something Rich will have to consider.
> Rod
>
--- End Message ---
--- Begin Message ---
Josh, Could you contact me off list. roderick at evparts.com
Roderick Wilde
EV Parts, Inc.
www.evparts.com
----- Original Message -----
From: "Rocketjosh" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, October 27, 2006 11:31 AM
Subject: Re: I can build your controller
I have much respect for the others making Controllers, I have one problem,
however-I cant get a quality controller at a reasonable price nor a
reasonable time-frame. I see an opportunity to provide a more reliable
source of quality controllers.
I have no intention of taking any business away from anyone. I want to
work with someone that is well versed in controller design, and HELP them
build something. Neither Otmar nor Rich are interested, I offered my help
directly to them already. Why not leave the Design work to the experts and
the Manufacturing to the experts?
By the way. the reason I ask for some basic information (BOM, schematic,
etc) is to get an INITIAL estimate of cost. How much will the parts cost
is sourced overseas? If we find that the cost of the parts is encouraging,
then we take the next step.
Here is my proposal: Someone acts as the Electrical Engineer providing
specifications for the controller and support during prototype development
and testing. They get Royalties for every unit sold in return.
In the end, more EVs will be built as a result of our work. Isn't that our
ultimate goal after all?
Josh
David Roden <[EMAIL PROTECTED]> wrote: Josh wrote :
I work in the consumer electronics industry ... I have visited
many factories in China and work closely with overseas
manufacturers and suppliers.
Warning, rant ahead!
Great, just what we need, twenty cent an hour Chinese sweatshop labor to
bury the good folks on the list who make their living, such as it is,
building high quality EV components.
Josh, I'll give you the benefit of the doubt since (I think) you're a
newbie
here, but how about a little concern for guys like Rich and Otmar, our
friends who work with list members to build what they want and produce a
high quality product? Rich at least has gone into debt to do this.
These guys are producing handbuilt products at mass-production prices, and
damn reasonable ones at that. I doubt that they're getting rich on it,
but
they are doing us a real service. Take their living away from them and
you
can forget them ever taking part in EVs as a business again.
Sorry if I seem a bit annoyed about this - I am. If we had nobody at all
building the components we need, it would be a different matter, but we
are
lucky to have people who do - and whom we can literally call up for help
and
support (try that with the guys in China).
I don't want a fight, and I don't want to seem ungrateful, but I really
wish
you would take your Chinese manufacturing connections somewhere else and
use
them for something else.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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--- Begin Message ---
David, I'm not going to stick up for human rights abuses or sweatshop labor
but I do not feel the problem is not all the fault of the Chinese. The Etek
is an example of a fine motor that was designed in England and had the
manufacturing set up in China by an American company called Briggs and
Stratton. It was a great motor and hobbyists here in this country are
whining daily because they can't get Eteks any more. Maybe we should be
boycotting American companies for doing business there. Check out your own
possessions sometime and find out where they are manufactured and who the
parent company is. It is our own American companies that are selling off our
jobs. I apologize for this being off charter but after all it was an EV List
administrator that brought it up. By the way, the Chinese government
recently dumped 5 billion dollars into Lithium battery research. Tell me
where our tax dollars are going in this country. I personally just want to
see more EVs on the road. Alltrax is an American company who manufactures in
this country and competes quite effectively against the Chinese so it can be
done. You do know that Curtis now has plants in China.
Roderick
----- Original Message -----
From: "David Roden" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, October 27, 2006 8:49 AM
Subject: Re: I can build your controller
Josh wrote :
I work in the consumer electronics industry ... I have visited
many factories in China and work closely with overseas
manufacturers and suppliers.
Warning, rant ahead!
Great, just what we need, twenty cent an hour Chinese sweatshop labor to
bury the good folks on the list who make their living, such as it is,
building high quality EV components.
Josh, I'll give you the benefit of the doubt since (I think) you're a
newbie
here, but how about a little concern for guys like Rich and Otmar, our
friends who work with list members to build what they want and produce a
high quality product? Rich at least has gone into debt to do this.
These guys are producing handbuilt products at mass-production prices, and
damn reasonable ones at that. I doubt that they're getting rich on it,
but
they are doing us a real service. Take their living away from them and
you
can forget them ever taking part in EVs as a business again.
Sorry if I seem a bit annoyed about this - I am. If we had nobody at all
building the components we need, it would be a different matter, but we
are
lucky to have people who do - and whom we can literally call up for help
and
support (try that with the guys in China).
I don't want a fight, and I don't want to seem ungrateful, but I really
wish
you would take your Chinese manufacturing connections somewhere else and
use
them for something else.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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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/ .
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Version: 7.1.408 / Virus Database: 268.13.16/504 - Release Date:
10/27/2006
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--- End Message ---
--- Begin Message ---
David Roden kirjoitti 27.10.2006 kello 18.49:
Josh, I'll give you the benefit of the doubt since (I think) you're
a newbie
here, but how about a little concern for guys like Rich and Otmar, our
I don't want a fight, and I don't want to seem ungrateful, but I
really wish
you would take your Chinese manufacturing connections somewhere
else and use
them for something else.
I´m a little surprised that the List Assistant Administrator
wants to restrict the discussion to a certain geographical area. As
far as I know the list is open to all. So there are many non-
americans on this list. Should we all get our ev-parts from Rich and
Otmar?
I wonder if there are any chinese members on this list?
Osmo Sarin
Finland
Europe
--- End Message ---
--- Begin Message ---
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--- Begin Message ---
I was comparing using a half-bridge module with a single switch, not
comparing modules with discretes. You *completely* missed my point;
*sigh*. The stray inductance applies because with a single switch, you
can't clamp the Vce within the same module. That's the whole point of
those capacitors that bolt right across the terminals. Everyone, please
read my last post again.
I hate modules. I hate IGBTs. I would never use the current-quality
modules in my own car, and IGBTs only reluctantly. But modules are
convenient, isolated, and easy to build with when someone else is paying
for them. The nice thing about MOSFETs: they're avalanche-rated.
There's a new 30V part that International Rectifier factory-tests at
nearly one joule of single-pulse avalanche energy!
I built a controller that got my EV on the road before I was even 18
years old, with 15 paralleled IRFZ48Vs in the TO-220AB package. It was
easy, efficient, and worked well. It was certainly low power, but it
made my car useful.
> I know; there are lots of reasons why you don't use IGBTs for
> synchronous rectifiers; voltage drop is just the most obvious one.
> MOSFETs happen to make pretty good synchronous rectifiers.
That's like me giving you a car without an engine, and me telling you it
won't run because it's out of gas.
The rated voltage drop only applies in one direction. The physics is
different when the voltage is opposite. In fact, the IGBTs will be
destroyed at about Vce=-18V [1]. But they obviously won't be destroyed
at Vce=+18V. They're not symmetric, so the forward voltage drop has
nothing to do with what happens in reverse.
Coming to the same conclusion with the wrong reason is merely a
coincidence. It doesn't help people understand the semiconductor
operation.
- Arthur
[1]: http://www.irf.com/product-info/datasheets/data/irg4bc10k.pdf
On Sat, 2006-10-28 at 13:00 -0500, Lee Hart wrote:
> Arthur W. Matteson wrote:
> > I know some have been confused about why one would choose a module for a
> > DC controller that has "wasted" parts. This seems counter-intuitive.
> > The reason my [quickly progressing] semi-open-source DC motor controller
> > uses half-bridge modules is the following:
> >
> > - Stray inductance! -
>
> Good point. Other good points are thermal performance, isolation, and
> current sharing. Modules are built to minimize these problems. If you
> "build your own" module with dozens of parallel devices, you have to
> solve all these problems yourself.
>
> >> [synchronous rectification] doesn't work with IGBTs. Even the best
> >> of them have twice the voltage drop of a good diode.
>
> > * A single tear falls from Arthur's face... *
>
> Sorry Arthur; I didn't mean to make you cry!
>
> I know; there are lots of reasons why you don't use IGBTs for
> synchronous rectifiers; voltage drop is just the most obvious one.
> MOSFETs happen to make pretty good synchronous rectifiers.
--- End Message ---
--- Begin Message ---
Yes done right it will work. It's a simple contactor controller mixed with
an Altrax. For instance if you want the after burner so to speak you cut
out the Alltrax & switch the pack from two strings of 72v to one string of
144v bone crushing uncontrolled power. This will quadruple your horse
power. Lawrence Rhodes......
> If you can't visualize this in your head, try drawing it out on paper.
> Then go back and trace the current flow through every wire.
>
> > Done right you won't blow up the controller but you will quadruple the
> > horse
> > power. Worlds Funniest Home videos here it come. Darwin Awards rules
> > apply. Lawrence Rhodes............
> > ----- Original Message -----
> > From: "Jack Murray" <[EMAIL PROTECTED]>
> > To: <[email protected]>
> > Sent: Friday, October 27, 2006 6:12 PM
> > Subject: Re: 2X Alltrax = Curtis ?
> >
> >
> >> Well I didn't try it, but after thinking it through the fets will see
> >> the full voltage differential even if the control circuits do not, and
> >> will blow, so that is enough to convince me.
> >> However, one option is to have the controller by-passed with some
> >> contactors for a full-on at higher voltage for top speed. A "turbo"
> >> button so to speak. Is it worth all the trouble? maybe, probably
> >> blow-up at least one controller debugging it.
> >> Jack
> >>
> >>
> >>
> >> Cor van de Water wrote:
> >> > Please do not try this at home.
> >> > Some people have tried adding an extra 12V battery in
> >> > series with a 36V controller and gotten away with it,
> >> > but if you double the pack voltage, the following
> >> > can happen to the controller:
> >> >
> >> > - the voltage (back-EMF) on the motor is lower than
> >> > half the pack voltage, so the controller gets more
> >> > volts than what it's built for and dies
> >> > (example: at 72V the back-EMF due to the motor RPM
> >> > may be 40V, when switched to 144V this means 104V
> >> > divided between controller and motor, when you
> >> > release the throttle, the controller goes boom.
> >> >
> >> > - the controller sees a negative motor voltage, because
> >> > for the controller at 72V the motor is connected to -72
> >> > which can cause a polarised device in the controller to
> >> > fail.
> >> >
> >> > - Dependent on the controller design, the freewheel diode
> >> > may be conducting continuously without throttle, sending
> >> > full 72V and high current to the motor, with throttle
> >> > you will be switched to 144V but the continuous current
> >> > may be overloading the freewheel diode(s).
> >> >
> >> > - If controller goes in current limit, the voltage on
> >> > the motor can easily drop below 72V, so the controller
> >> > sees more than 72V.
> >> >
> >> > - Probably there are other issues that depend on the
> >> > design of the controller, so only inspection of it
> >> > can tell you if this idea is even feasible.
> >> >
> >> > You do have a big chance of blowing up your controller,
> >> > it is on you if you want to test it or use a controller
> >> > fit for the job.
> >> >
> >> > Success,
> >> >
> >> > 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 damon henry
> >> > Sent: Friday, October 27, 2006 12:55 PM
> >> > To: [email protected]
> >> > Subject: RE: 2X Alltrax = Curtis ?
> >> >
> >> >
> >> >
> >> >>I'd consider a 144V pack and a single 7245. Arrange the pack as 2 72V
> >> >>strings and parallel them at lower speeds so the controller runs of
> >> the
> >> >>72V pack and all batteries are discharged evenly. Above some speed,
> >> >>switch the packs in series and leave the controller connected across
> >> >>only the top 72V segment. This allows the controller to vary voltage
> >> to
> >> >>the motor between 72V and 144V.
> >> >
> >> >
> >> >
> >> > Wow, this is a cool idea. I have been wanting to try a higher
voltage
> > on my
> >> >
> >> > motorcycle. Since my controller is good for 24 - 48 volts, I could
> >> use
> > this
> >> >
> >> > techique and try up to 96 volts without buying a new controller.
> >> >
> >> > Damon
> >> >
> >> > _________________________________________________________________
> >> > Find a local pizza place, music store, museum and more...then map the
> > best
> >> > route! http://local.live.com?FORM=MGA001
> >> >
> >> >
> >>
> >
> >
>
>
> --
> If you send email to me, or the EVDL, that has > 4 lines of legalistic
> junk at the end; then you are specifically authorizing me to do whatever I
> wish with the message. By posting the message you agree that your long
> legalistic signature is void.
>
--- End Message ---
--- Begin Message ---
Thanks Lee. I'm about to put the second heater in
today. In Fairbanks, Alaska we can get -40F, however
in last few years those days only occured a few times.
But we do get lots of -20F.
Yesterday, driving around in 0F, the 75% element was
able to defog the front windshield, but my feet were
cold. I agree that the air it was making wasn't warm,
but it was better than the outside air.
I was going to try some foam under my feet to see if
it helps. I may still have some holes from the engine
compartment.
--- Lee Hart <[EMAIL PROTECTED]> wrote:
> mike golub wrote:
> > Questions
> > 1. Is it OK to use styrofoam to insulate the cab?
> The
> > stuff is flammable, but I wonder what type of
> fire
> > danger there is?
>
> Styrafoam is a good insulator, and cheap. Yes, it
> burns; but 99% of the
> plastics and fabrics (and oil and gasoline) used in
> cars also burn. Very
> little attention is given to fire safety in cars.
>
> The problems with styrafoam are usually in other
> areas. It is bad
> environmentally, because of the chemicals used to
> make it. It is
> attacked by almost any hydrocarbon; gasoline, oil,
> and most glues and
> adhesives will disolve it. It is mechanically weak,
> and easily gets beat
> up. It "squeaks" if there is any movement.
>
> But if these concerns are ok, by all means, use it.
>
> > 2- If I add the second element. Do I mount it so
> the
> > air goes through both or do I just mount in the
> same
> > plane as the other element. I wonder because if I
> > added a third one I'd run out of space?
>
> The air passing through the element tends to have a
> certain temperature
> rise. The amount depends on the voltage and airflow.
> You can get
> temperature rises on the order of 30-60 deg.F.
>
> Suppose you set it up for a 40 deg.F rise. When it
> is 60 deg.F outside,
> you get 100 deg.F air (great). When it is 0 deg.F
> outside, you get 40
> deg.F air (not so great -- no "heat" and it can
> barely defog the
> windshield).
>
> You can reduce the airflow to get a higher
> temperature rise; but you
> also get less total heat by doing this. That's
> because the hotter the
> element gets, the less current it draws and the less
> heat it makes.
>
> If you live in a place that never gets particularly
> cold, put the two
> elements side-by-side. If you live in a place that
> gets very cold (like
> Minnesota), put the elements one in front of the
> other, so one preheats
> the air by (say) 40 deg.F, and the second one heats
> it another 40 deg.F.
> Now you can get 80 deg.F air when it is 0 deg.F
> outside.
> --
> 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
>
>
____________________________________________________________________________________
Cheap Talk? Check out Yahoo! Messenger's low PC-to-Phone call rates
(http://voice.yahoo.com)
--- End Message ---
--- Begin Message ---
G'day Bob, and All
At 03:05 PM 28/10/06 -0400, Bob wrote:
> Lawrence Rhodes wrote:
> > .... David there is simply nothing
> > to be had but Curtis, Zapi & Altrax for the most part.
> On a related note, anyone try the Navitas TSE 96v/600A Controller yet?
>
> http://navitastechnologies.com/PDF/TSE600-96_Brochure.pdf
>
> Just curious...
Hi Guyz;
Boy! That looks like just what I could use in my 90 volt Sentra, the one
with the busted Cursit!
Can your 90 Volt Sentra run OK on 260 amps continuous? That said, they
don't list the curve that goes from 600A down to the 260A continuous point,
so it might be OK. It certainly looks a Cursit-equivalent controller, but
designed to have greater efficiency. It is touted as a forklift traction
controller, not a road-EV controller.
Interesting as well is that they are in run-up to release an 80V AC drive
system at up to 550A.
Regards
[Technik] James
--- End Message ---
--- Begin Message ---
I'm currently ato 120vdc, but I might go to 132 ...
144 vdc, because of range...but then I need to worry
about my dc-dc convertor
--- canev <[EMAIL PROTECTED]> wrote:
> 120 volts in the minimum voltage for off the shelf
> ceramic's. We have a
> special 36 - 96 volt unit that also works very well
> at 120 volts. I have
> found over the years that the 120 volt heaters just
> don't put out very
> much unless they are used at 144 volts or higher.
> I also like wiring two units in one heater box but
> prefer to wire half
> of each heater to separate contactors. On "low" you
> power up half of
> each heater which are installed side by side and on
> "high" you power
> both up.
> This minimizes the effect of passing cold air
> through the one heater
> that is not on as Don experienced.
> You should be able to solder directly to the heater
> terminal if it is a
> good quality unit.
> We have now sold over 800 of our EV ceramic heaters
> which are available
> from most of your regular EV suppliers.
>
> BFN
> Randy
>
> >>
> >> Subject:
> >> Re: brrr cold zero F today
> >> From:
> >> Dave Cover <[EMAIL PROTECTED]>
> >> Date:
> >> Fri, 27 Oct 2006 15:42:52 -0700 (PDT)
> >> To:
> >> [email protected]
> >>
> >> To:
> >> [email protected]
> >>
> >>
> >>--- mike golub <[EMAIL PROTECTED]> wrote:
> >>
> >>
> >>
> >>>I installed my heater today. It was 0 degrees F
> when I
> >>>left the garage this morning.
> >>>One of the pins broke off that Mr.Holmes black
> box
> >>>"ceramic" element.
> >>>
> >>>
> >>
> >>I'm installing ceramic heaters too and I have a
> problem that relates to what you described. In
> >>both the elements I bought the wires are directed
> straight away from the top. I need them to come
> >>off at a 90 degree angle, basically parallel to
> the airflow through the heater. But I can't bend
> >>the tabs and the metal the wires need to connect
> to appears to be aluminum. How do I solder or
> >>bond copper wire to aluminum? Mike, do you have an
> easy way to reattach the wire that broke off?
> >>
> >>Thanks
> >>
> >>Dave Cover
> >>
> >>
>
> --
>
>
>
> Canadian Electric Vehicles Ltd.
> PO, Box 616, 1184 Middlegate Rd.
> Errington, British Columbia,
> Canada, V0R 1V0
> Phone: (250) 954-2230
> Fax: (250) 954-2235
> Website: http://www.canev.com
> Email: [EMAIL PROTECTED]
> Manufactures of: "Might-E Truck"
> EV conversion Kits and components
>
>
____________________________________________________________________________________
Get your email and see which of your friends are online - Right on the New
Yahoo.com
(http://www.yahoo.com/preview)
--- End Message ---
--- Begin Message ---
In a DC series motor application, It has NOTHING to do with back emf, it
is a characteristic of a circuit (OCV, opencircuit voltage)
A circuit is in a big loop, break it anywhere and the open circuit
voltage will be at max.
an example :
20 batteries in a pack to a big resistor and a motor back to
negative.(The rating of that breaker must be for the pack voltage not half)
The resistor is the controller with mosfets "ON" dropping the voltage to
the motor and giving off a little heat, The current thru the mosfets is
the same as thru the motor and the voltage drop is Vdrop= IR; V-Vdrop
is at the motor. (I = current, R = resistance ...reactance technically,
we got inductance)
ok now the mosfets all open and the current drops to zero, Vdrop goes to
zero and V V-0 ...is ....pack voltage .
Of course this happens 15,000 times a second and the voltage climbs
slower switching on and spikes higher switching off because of the
inductance.
--- End Message ---
--- Begin Message ---
HEY, maybe we can get Halaburton to build us one!
Rich
----- Original Message -----
From: "Roderick Wilde" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, October 28, 2006 5:01 PM
Subject: Re: I can build your controller, off topic
> David, I'm not going to stick up for human rights abuses or sweatshop
labor
> but I do not feel the problem is not all the fault of the Chinese. The
Etek
> is an example of a fine motor that was designed in England and had the
> manufacturing set up in China by an American company called Briggs and
> Stratton. It was a great motor and hobbyists here in this country are
> whining daily because they can't get Eteks any more. Maybe we should be
> boycotting American companies for doing business there. Check out your own
> possessions sometime and find out where they are manufactured and who the
> parent company is. It is our own American companies that are selling off
our
> jobs. I apologize for this being off charter but after all it was an EV
List
> administrator that brought it up. By the way, the Chinese government
> recently dumped 5 billion dollars into Lithium battery research. Tell me
> where our tax dollars are going in this country. I personally just want to
> see more EVs on the road. Alltrax is an American company who manufactures
in
> this country and competes quite effectively against the Chinese so it can
be
> done. You do know that Curtis now has plants in China.
>
> Roderick
>
>
> ----- Original Message -----
> From: "David Roden" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Friday, October 27, 2006 8:49 AM
> Subject: Re: I can build your controller
>
>
> > Josh wrote :
> >
> >> I work in the consumer electronics industry ... I have visited
> >> many factories in China and work closely with overseas
> >> manufacturers and suppliers.
> >
> > Warning, rant ahead!
> >
> > Great, just what we need, twenty cent an hour Chinese sweatshop labor to
> > bury the good folks on the list who make their living, such as it is,
> > building high quality EV components.
> >
> > Josh, I'll give you the benefit of the doubt since (I think) you're a
> > newbie
> > here, but how about a little concern for guys like Rich and Otmar, our
> > friends who work with list members to build what they want and produce a
> > high quality product? Rich at least has gone into debt to do this.
> >
> > These guys are producing handbuilt products at mass-production prices,
and
> > damn reasonable ones at that. I doubt that they're getting rich on it,
> > but
> > they are doing us a real service. Take their living away from them and
> > you
> > can forget them ever taking part in EVs as a business again.
> >
> > Sorry if I seem a bit annoyed about this - I am. If we had nobody at
all
> > building the components we need, it would be a different matter, but we
> > are
> > lucky to have people who do - and whom we can literally call up for help
> > and
> > support (try that with the guys in China).
> >
> > I don't want a fight, and I don't want to seem ungrateful, but I really
> > wish
> > you would take your Chinese manufacturing connections somewhere else and
> > use
> > them for something else.
> >
> >
> > 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/ .
> > = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> >
> >
> >
> >
> > --
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > Version: 7.1.408 / Virus Database: 268.13.16/504 - Release Date:
> > 10/27/2006
> >
> >
>
>
>
> --
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.1.408 / Virus Database: 268.13.17/505 - Release Date:
10/27/2006
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.408 / Virus Database: 268.13.17/505 - Release Date:
10/27/2006
>
>
--- End Message ---
