EV Digest 6963
Topics covered in this issue include:
1) Re: Sailboat Conversion
by Dan Frederiksen <[EMAIL PROTECTED]>
2) RE: Weird Questions
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
3) RE: reed switch application
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
4) RE: reed switch application
by "Phil Marino" <[EMAIL PROTECTED]>
5) Typical EV Motor
by "Rob Hogenmiller" <[EMAIL PROTECTED]>
6) Re: To Gear or Not to Gear a Motorcycle (was Manly EV's, etc.)
by Tom Parker <[EMAIL PROTECTED]>
7) Re: Controler space
by "TrotFox Greyfoot" <[EMAIL PROTECTED]>
8) Re: S10 transmission
by [EMAIL PROTECTED]
9) Re: Chains and belts (was Re: ft-lbs or lbs-ft
by "TrotFox Greyfoot" <[EMAIL PROTECTED]>
10) Re: Cheap
by Jeff Shanab <[EMAIL PROTECTED]>
11) RE: Typical EV Motor
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
12) n00b in your midst
by "John Labrey" <[EMAIL PROTECTED]>
13) RE: n00b in your midst
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
14) RE: n00b in your midst
by "John Labrey" <[EMAIL PROTECTED]>
15) Re: Weird Questions
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Chains and belts (was Re: ft-lbs or lbs-ft
by Jeff Shanab <[EMAIL PROTECTED]>
17) RE: n00b in your midst
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
18) Re: Cheap
by Tim Humphrey <[EMAIL PROTECTED]>
19) Re: Sailboat Conversion
by "Mark Ward" <[EMAIL PROTECTED]>
20) RE: EV air conditioning, how to connect motor?
by Christopher Robison <[EMAIL PROTECTED]>
21) Re: Sailboat Conversion
by "jerryd" <[EMAIL PROTECTED]>
22) RE: EV air conditioning, how to connect motor?
by Christopher Robison <[EMAIL PROTECTED]>
23) RE: EV air conditioning, how to connect motor?
by "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
24) Re: Nobody wants my money.. (rant for the day)
by Ian Hooper <[EMAIL PROTECTED]>
25) RE: To Gear or Not to Gear a Motorcycle (was Manly EV's, etc.)
by "Alan Brinkman" <[EMAIL PROTECTED]>
--- Begin Message ---
you could give it a lead acid keel then : )
keep the batteries in a custom pod downthere and serve a dual purpose :)
--- End Message ---
--- Begin Message ---
Rob,
Your idea would work but I think you would not be able to
maintain 60mph for very long. You would need a 156V or better system
with a lot of AH to go any appreciable distance. How about going the
other way around? Use the electric drive for your in town driving and
the gas engine for highway speeds? To do this on a focus all you would
have to do theoretically is replace the back axle with a ford mustang
rear end. Couple the pumpkin flange to a pulley and mount the electric
motor to the axle and attach a chain system between the two. That way
you can work out optimal gearing to achieve at least 45 mph in direct
drive. Netgain technology has worked out a controller that makes it
possible to drive an electric motor while the engine is running for a
parallel motor hybrid vehicle. Currently their system is only for
trucks but there are tons of OBD2 interfaces out there that could give
you the LOD (engine load) input or speed input necessary to use the
electric motor. There are also plenty of people who are familiar with
the CAN protocol to help you program a system that would ask the gas
engines ECU the right questions. That way you can have Full electric
(gas engine in neutral), full gas, electric assist (hybrid mode). I
hope this helps.
jody
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Rob Hogenmiller
Sent: Thursday, June 28, 2007 8:04
To: EV Discussion
Subject: Weird Questions
I thought I might take a moment to explain the basis of a few questions
I've asked, as they might seem a little weird.
What I'm hoping to build is an EV-Hybrid.
The Concept.
Use an existing gas powered vehicle (in my case a 2007 Ford Fusion) to
propel the vehicle up to 60mph (legal highway speed in my state).
Once reaching 60mph, flip the electric motor on to maintain 60mph.
So basically I'm trying to learn the terminology and also understand
what kind of components I would need to accomplish this project.
Currently I'm thinking of something very simple a on off switch no
controller, and cut off switch (not sure if that is the right term) when
the brakes are applied, basically like the way cruise control works. I
would then set my cruise control on the car at 55mph, or whatever to
kick in if the electric motor became under stress.
This should bump my gas mileage very high, I'm hoping for well over
100mpg.
Obviously this type of setup would not benefit all, but would be a nice
setup for a commuter that has a fair share of highway
traveling/commuting.
You can see some of the things I'm learning/progress at www.7change.com
--- End Message ---
--- Begin Message ---
Crap. I realized later WHY you would want the reed switch in there -
hills or anytime you want to move the car while holding the brake. I
think you would want the reed switch to engage a little earlier than 150
amps though as mentioned in another post.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Dewey, Jody R ATC COMNAVAIRLANT, N422G5G
Sent: Thursday, June 28, 2007 8:22
To: ev@listproc.sjsu.edu
Subject: RE: reed switch application
Is there any reason why you wouldn't just use the brake switch to
control the SPDT relay directly? Why have two switches to control the
same thing?
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Paul
Sent: Wednesday, June 27, 2007 21:24
To: ev@listproc.sjsu.edu
Subject: reed switch application
I've spent the past couple of hours doing some online reading about reed
switches. I have found a couple of questions unanswered. I bet some list
members have the answers.
My situation is that I want to add a reed switch along one of my EVs
motor power wires as part of a system to shut a Curtis controller down
quickly in the event it shorts on. The basic concept is [brake light on
power] > [reed switch] > [SPDT relay with coil diode]. The switching
contact is connected to ignition power in. The N.C. contact goes to the
main contactor. The N.O. contact is connected to the one side of the
coil and the other side of the coil is connected to ground. The brake
light on power and reed switch in series can apply power to the same
side of the coil as the N.O. contact to pull it in and the N.O. contact
will latch it on.
I have been looking at the test coils for reed switches and it appears
that the reed switch to be tested is supposed to be slid inside the
coil. If that is correct would that mean that I should put a round core
around the power cable and slide the reed switch inside the same
direction as the cable? When the power cable just passes through (or the
reed switch is laid on the wire) what percentage of a turn is that
approximately? Suggestions about the amp-turn rating of the selected
reed switch would also be useful. I'm trying to get in the ball park
before I just start buying parts half randomly :-)
Thanx,
Paul "neon" G.
--- End Message ---
--- Begin Message ---
This may seem too simple, but why not just have the main contactor open when
the brake lights are on?
Simpler is more reliable.
You would have to use your left foot on the brake, and your right foot on
the accelerator to use the motor and brakes at the same time, anyway.
I've never done this, even in an ICE stick shift car. And, an electric car
is certainly easier to get started up a hill than an ICE.
I have, on occasion, used the handbrake to start up a steep hill, but that
wouldn't be a problem with the simpler "brakes-on means contactor open"
setup.
Phil Marino
From: "Dewey, Jody R ATC COMNAVAIRLANT, N422G5G" <[EMAIL PROTECTED]>
Reply-To: ev@listproc.sjsu.edu
To: <ev@listproc.sjsu.edu>
Subject: RE: reed switch application
Date: Thu, 28 Jun 2007 08:46:34 -0400
Crap. I realized later WHY you would want the reed switch in there -
hills or anytime you want to move the car while holding the brake. I
think you would want the reed switch to engage a little earlier than 150
amps though as mentioned in another post.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Dewey, Jody R ATC COMNAVAIRLANT, N422G5G
Sent: Thursday, June 28, 2007 8:22
To: ev@listproc.sjsu.edu
Subject: RE: reed switch application
Is there any reason why you wouldn't just use the brake switch to
control the SPDT relay directly? Why have two switches to control the
same thing?
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Paul
Sent: Wednesday, June 27, 2007 21:24
To: ev@listproc.sjsu.edu
Subject: reed switch application
I've spent the past couple of hours doing some online reading about reed
switches. I have found a couple of questions unanswered. I bet some list
members have the answers.
My situation is that I want to add a reed switch along one of my EVs
motor power wires as part of a system to shut a Curtis controller down
quickly in the event it shorts on. The basic concept is [brake light on
power] > [reed switch] > [SPDT relay with coil diode]. The switching
contact is connected to ignition power in. The N.C. contact goes to the
main contactor. The N.O. contact is connected to the one side of the
coil and the other side of the coil is connected to ground. The brake
light on power and reed switch in series can apply power to the same
side of the coil as the N.O. contact to pull it in and the N.O. contact
will latch it on.
I have been looking at the test coils for reed switches and it appears
that the reed switch to be tested is supposed to be slid inside the
coil. If that is correct would that mean that I should put a round core
around the power cable and slide the reed switch inside the same
direction as the cable? When the power cable just passes through (or the
reed switch is laid on the wire) what percentage of a turn is that
approximately? Suggestions about the amp-turn rating of the selected
reed switch would also be useful. I'm trying to get in the ball park
before I just start buying parts half randomly :-)
Thanx,
Paul "neon" G.
_________________________________________________________________
Need a break? Find your escape route with Live Search Maps.
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--- End Message ---
--- Begin Message ---
How much does a typical EV motor weigh?
Also what might be a typical dimensions of a motor?
(I've seen 8" mentioned often, figure that is the diamter, but how long are
they.)
God bless
--- End Message ---
--- Begin Message ---
On Wed, 2007-06-27 at 16:48 -0700, Loni wrote:
> I think I understand now. Regardless of pack voltage and gearing, when I
> demand acceleration the system has to generate X watts. Once the limits of
> pack voltage are reached, X watts are achieved by increasing amperage.
> Right?
Yes. But you might have more luck thinking about torque, rather than
power.
As has been said before, for most all electric motors, torque is
directly proportional to current. The voltage required to push any given
current through a motor goes up with the motor speed.
As an example (I'm making all these numbers up), with your motor and
gearing, you might require 100A to generate 250Nm of wheel torque. This
current will be the same at 0km/h or 120km/h. The difference is that at
0km/h you might need 8 volts to push 100A through the motor, and at
120km/h you might need 300 volts.
So your balance is this:
1) More current heats your motor & controller, shortening their life.
2) More current may shorten the calendar life of your batteries.
3) More current will reduce your efficiency (for various reasons).
4) More rpm shortens the life whatever is turning.
To find out how big any of these effects are, you have to talk to the
manufacturer.
> Most of the respondents here have suggested that direct drive is the way to
> go. That may be true, but I'm curious whether that's the general consensus
> when pack voltage is limited to, say, 120 V due to packaging/range
> constraints. If, for example, I hold the motor at 9000 rpm to maintain top
> speed, it seems that I would be drawing big amps while unnecessarily
> decreasing motor life-expectancy due to centrifugal force (with most
> motors). Or I could change gear ratios and still demand the same wattage,
> but at a lower motor rpm. True?
I think you've missunderstood the relationship between current, voltage,
speed and torque.
If you gear your motor for higher motor speed, the torque required at
the motor for any given wheel torque will be lessened. Less torque means
less current. You don't get a free lunch, because you need more voltage
to push this current through the motor.
> I know it seems unrealistic to think that an operator might hold rpms at
> 9000 for any length of time, but if I'm going to start manufacturing
> motorcycles in any volume, I have to condsider every possibility.
Talk to a manufacturer. You may find the life of the motor at the
maximum rated speed is not substantially different than the life of the
motor at half that. This is especially true when you consider the
reduced current in a faster turning motor.
You fear that using more rpm and less current above will cause your bike
to fail due to (4), but (1) acts to make it last longer.
A cooler motor turning quickly might actually last longer than a hot
motor turning slowly. Both will likely last far longer than necessary.
--- End Message ---
--- Begin Message ---
Another thing to consider when thinking about vacuum-based switching
is, "How do you maintain vacuum?" Let just the wrong amount of air in
there and you'll end up with a plasma that will very quickly destroy
both the electronics and likely a good portion of the case, if metal.
Dry air would be a better choice I would think.
Trot, the sucky, fox... } ; ]
On 6/28/07, Lee Hart <[EMAIL PROTECTED]> wrote:
No; this is not the case. At the breakdown voltage between the two
metals, the electric field strength is high enough to rip electrons
loose from the metals themselves. The electrons form the "gas" that
carries the current from one to the other. The electrons slam into the
positive side, giving up their kinetic energy and causing major heating
at the point of contact. When the positive metal gets hot enough from
this, positive metal ions start boiling off, and become a second "gas"
to carry charge in the opposite direction. These positive ions bombard
the negative side, causing it to heat up as well.
Anyone who has used high power vacuum tubes has seen this effect. When
you overload the tube, it can arc over between cathode and plate, heat
them to incandescence, and they will melt and weld.
> With this same thought a controller switch sealed in a vacuum would
> have no arc...
Yes, it will (see above). In fact, the breakdown voltage in a vacuum is
*lower* than it would be with air. Air is a better insulator than a vacuum.
However, air contains oxygen. Once you do strike an arc in air, the
oxygen erodes the metal very quickly -- much quicker than in vacuum.
> And as far as noise I am sure that the arch would be a good part of
> the noise.
Do you mean acoustic noise (the "clack" of a contactor pulling in)? This
is purely mechanical; a contactor is just as loud with no current
flowing as it is at full load.
Or do you mean electrical noise (as in RF interference)? This is always
present with contacts, regardless of whether there is air, vacuum, oil,
or anything else between them. The electrical noise is caused by the
sudden (nearly instantaneous) change in voltage and current as the
contact opens and closes the circuit.
--
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
--
| /\_/\ TrotFox \ Always remember,
| ( o o ) AKA Landon Solomon \ "There is a
| >\_/< [EMAIL PROTECTED] \ third alternative."
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--- Begin Message ---
Jim,
The donor vehicle has/had a 5 speed transmission that was broken and
removed 1993
Presently I'm using an 1987 4 speed transmission in my 84 Chevy EV.
--- End Message ---
--- Begin Message ---
Think of belt slip as a feature. Especially with A/C compressors and
superchargers when there is a sudden surge in the accessory's power
demand the belt absorbs a portion of that surge instead of trying to
transfer it all back to the crank where damage could occur. You're
also less likely to damage the belt if it can slip. A toothed belt
may shear teeth off in the same situation.
It's a feature, not a bug! ; ]
Trot, the mechanically-minded, fox...
On 6/28/07, Victor Tikhonov <[EMAIL PROTECTED]> wrote:
This reminds me to ask: teethed belts don't require as much tension as
V-ones and don't slip. Wonder why they aren't used more widely? Sure,
alternator and A/C compressor don't require exact timing as valves do,
but still, is it just noise and extra expense of teethed belts and
pulleys, or some other technical reasons?
Victor
--
| /\_/\ TrotFox \ Always remember,
| ( o o ) AKA Landon Solomon \ "There is a
| >\_/< [EMAIL PROTECTED] \ third alternative."
--- End Message ---
--- Begin Message ---
I have been designing a group 22-ish module with 26650's and integral BMS
I have planned on groups of 12 cells in parallel useing nickel tabs to
buss bars with notches in the nickel tabs to serve as fuses in case of
short.
Each group of 12 has two temperature sensors,
Hopefully 12 of these modules will fit and can be interconnected in a
few choices
6 series groups of 2*12 parallel cells yielding [EMAIL PROTECTED]
or
4 groups of 3*12 yielding [EMAIL PROTECTED]
or
3 groups of 4*12 yielding [EMAIL PROTECTED]
I will use 15 of the first one as I have a 288V lead conversion at the
moment and my range doesn't need to be so great.
Someone with a 156V zilla will probably use 12 of the 2nd version
And some extreme range nut or low voltage conversion will use the 3rd
option.
I will start with bypass regulators, and see how they perform. The micro
will control them and interface to the charger and a dash display.
I don't have much money at the moment so the going is slow, but I got
the weld controller and transformer and I have quotes out for the darn
nickel tabs. (Try getting A123 to sell you cells and tabs seperately
LOL). The silver lining is that by the time I am ready to buy cells,
they will most certainly cost less :-)
--- End Message ---
--- Begin Message ---
My netgain 9" motor weighs 150 pounds. For dimensions go to the netgain
website. They have drawings and everything.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Rob Hogenmiller
Sent: Thursday, June 28, 2007 9:07
To: EV Discussion
Subject: Typical EV Motor
How much does a typical EV motor weigh?
Also what might be a typical dimensions of a motor?
(I've seen 8" mentioned often, figure that is the diamter, but how long
are
they.)
God bless
--- End Message ---
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Subject: RE: To Gear or Not to Gear a Motorcycle (was Manly EV's, etc.)
Date: Thu, 28 Jun 2007 07:45:14 -0700
Message-ID: <[EMAIL PROTECTED]>
From: "Alan Brinkman" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Content-Transfer-Encoding: 8bit
Mark,
Cool ride. I can see lots of thought and time went into your frame.
How do you get the single air suspension to stay balanced, both front
and rear at ride height? Is there a spring or two that assist at
traveling height?
How did you keep the curb weight so reasonable? Does the aluminum frame
contribute a lot to that?
Very nice!
Alan Brinkman
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mark Eidson
Sent: Wednesday, June 27, 2007 5:46 PM
To: ev@listproc.sjsu.edu
Subject: Re: To Gear or Not to Gear a Motorcycle (was Manly EV's, etc.)
Following similar logic I have arrived at this design:
http://www.austinev.org/evalbum/preview.php?vid=1231
Hopefully I will get the 15 mi range at a reasonable DOD. I won't be
going over 50MPH often or for long stretches. Need to get it on the
licensed and on the road and find out. me
On 6/27/07, Peter VanDerWal <[EMAIL PROTECTED]> wrote:
>
> > I think I understand now. Regardless of pack voltage and gearing,
when I
> > demand acceleration the system has to generate X watts. Once the
limits of
> > pack voltage are reached, X watts are achieved by increasing
amperage.
> > Right?
>
> Correct.
>
> > When I look around, though, there doesn't seem to be a
one-size-fits-all
> > solution for every application.
>
> Absolutely, there is no solution that fits every problem. Vehicles,
> especially EVs are a compromise. Do we want better handling or more
> comfort? Lower weight and drag or more interior space?
> Multispeed transmission, or more batteries?
>
> > Most of the respondents here have suggested that direct drive is the
way
> > to go.
>
> with a motorcycle? Abolutely. The trade off is that without a
multispeed
> transmission, the motor has to develope more torque and/or RPM to give
the
> same performance.
> With a car this means larger or more motors and more powerful
controllers.
> It means the same thing with a motorcycle, however motorcycles are
> smaller to begin with so using a normal car size motor/controller
already
> gives you the needed torque advantage.
>
> >That may be true, but I'm curious whether that's the general
consensus
> Almost all of the successful drag racing bikes forgo a transmission,
this
> is because of experience as much as theory.
>
> > when pack voltage is limited to, say, 120 V due to packaging/range
> > constraints. If, for example, I hold the motor at 9000 rpm to
maintain top
> > speed, it seems that I would be drawing big amps while unnecessarily
> > decreasing motor life-expectancy due to centrifugal force (with most
> > motors). Or I could change gear ratios and still demand the same
wattage,
> > but at a lower motor rpm. True?
> Cumulative centifugal force seems to have very little effect on motor
life
> expectancy. As long as the motor is rated to handle the RPMs, then it
> will continue to do so long past the time the motorcyle is scrap.
> Gear it so it can reach your maximum designed speed while not quite
> reaching your maximum RPM. THen look at what kind of torque it can
> produce and see if that will meet your goals. If not, get a more
powerful
> motor/controller.
>
> Another possiblity is to figure out how to build a small, litewieght
two
> speed transmission.
> >
> > I know it seems unrealistic to think that an operator might hold
rpms at
> > 9000 for any length of time, but if I'm going to start manufacturing
> > motorcycles in any volume, I have to condsider every possibility.
>
> Well, quite frankly, any motorcycle that can meet your designed speed
> won't be able to do it for long unless you are spending a fortune on
LiPol
> batteries. At which point not many people will be willing to fork out
the
> cash needed anyway, so the number of people abusing the bike will also
be
> pretty small.
>
> The power requirements to simply maintain 60 mph are fairly large on a
> bike. Something like 5 or 6kw. If you are using Lead-Acid batteries
> you'd be lucky to get 2kwh onboard, that means a range of maybe 15
miles,
> or a 7.5 mile radius.
>
> LiPol will give you much more range, perhaps 4 or 5 times as much.
But
> will cost a lot.
>
> You are focusing on the motor and that is the least of your problems.
>
>
> > Lon Hull,
> > Portland, OR
> >
> >>
> >> On 6/26/07, Loni <[EMAIL PROTECTED]> wrote:
> >>>Of course I'd love to just dump in more voltage or current, but
> >>> design constraints won't allow it. Will changing gears allow me to
stay
> >>> in
> >>> the fat part of the motor's torque curve while continuing to
accelerate
> >>> to
> >>> max speed, or should I just wring the motor out and accept
whatever
> >>> output
> >>> it's capable of as current demand outstrips pack capacity?
> >>
> >
> >
>
>
> --
> 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.
>
>
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