EV Digest 5315
Topics covered in this issue include:
1) Re: Thanks for all the insight on my project SCR fix from Lee Hart.
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
2) bigger vacuum made huge difference in brakes
by elaine chiu <[EMAIL PROTECTED]>
3) Re: Motor options
by Victor Tikhonov <[EMAIL PROTECTED]>
4) 150vDC-12vDC converters
by "Myles Twete" <[EMAIL PROTECTED]>
5) Re: Motor options
by "Ryan Stotts" <[EMAIL PROTECTED]>
6) Re: Circuit breakers, fuses, =?ISO-8859-1?Q?GFCI=B4s_=28newbie?=
=?ISO-8859-1?Q?=29?=
by Victor Tikhonov <[EMAIL PROTECTED]>
7) Re: identifying mystery forklift motors
by Darin <[EMAIL PROTECTED]>
8) =?iso-8859-1?Q?RE:_Circuit_breakers=2C_fuses=2C_GFCI=B4s_=28newbie=29?=
by "Don Cameron" <[EMAIL PROTECTED]>
9) Re: Dual Motors to FWD axles - Anyone done it ??
by "Chris Robison" <[EMAIL PROTECTED]>
10) Re: Dual Motors to FWD axles - Anyone done it ??
by "Joe Smalley" <[EMAIL PROTECTED]>
11) Re: Dual Motors to FWD axles - Anyone done it ??
by Ricky Suiter <[EMAIL PROTECTED]>
12) Re: Circuit breakers, fuses, =?iso-8859-1?Q?GFCI=B4s?= (newbie)
by Lee Hart <[EMAIL PROTECTED]>
13) RE: Motor options
by Mike & Paula Willmon <[EMAIL PROTECTED]>
14) Re: Circuit breakers, fuses, GFCI´s (newbie)
by Mark Freidberg <[EMAIL PROTECTED]>
15) Re: Motor options
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Motor options
by Lee Hart <[EMAIL PROTECTED]>
17) Re: Circuit breakers, fuses, =?iso-8859-1?Q?GFCI=B4s?= (newbie)
by Lee Hart <[EMAIL PROTECTED]>
18) Re: Circuit breakers, fuses, GFCI´s (newbie)
by Mark Freidberg <[EMAIL PROTECTED]>
19) Re: Thanks for all the insight on my project
by "Paul G." <[EMAIL PROTECTED]>
20) Re: Dual Motors to FWD axles - Anyone done it ??
by "Paul G." <[EMAIL PROTECTED]>
21) Re: Circuit breakers, fuses, =?ISO-8859-1?Q?GFCI=B4s_=28newbie?=
=?ISO-8859-1?Q?=29?=
by Victor Tikhonov <[EMAIL PROTECTED]>
22) Re: Dual Motors to FWD axles - Anyone done it ??
by "mike young" <[EMAIL PROTECTED]>
23) Re: Need help about sepex Motor and alltrax DCX please
by "Philippe Borges" <[EMAIL PROTECTED]>
--- Begin Message ---
One little trick Lee Hart mentioned to me in some detail is to use
capacitors as a sort of an electric version of a water hammer preventer to
allow the EV-1 controller to be more efficient by eliminating the ripple
current.. Read below and thanks again to Lee for all his very good advice
and knowledge. Below are a few emails to the list between Lee and myself.
LR......
.
Lawrence Rhodes wrote:
I have an SCR based controller in the Electravan that switches
at 1500 hz with inadequate filtering on the battery side.
Is it possible that the battery sees high current pulses and
behaves more like it is discharging at 1000 amps than 100 and
consequently has much less capacity.
Yes, it is possible; even probable. You can measure the battery ripple
current with a multimeter. Measure across your battery current shunt, or
pick two spots along one of the wires from your batteries to the
controller. For example, the positive terminal of the battery and the
other end of that wire that connects to the controller. The voltage drop
in this wire is proportional to current.
Connect wires from these points to your multimeter, and go for a drive.
While cruising at some constant speed, measure the DC voltage and the AC
voltage. Their ratio is the percent ripple current. If the AC voltage is
more than about 10% of the DC voltage, then your batteries would benefit
from the addition of filter capacitors.
These old SCR controllers usually didn't have a large input filter
capacitor bank. There were several reasons.
First, they expected them to be used with huge forklift batteries, which
already have lots of capacitance (a "mere" 1000 amp load for these
batteries isn't a high rate :-) They may not have been aware that lack
of capacitors would be a problem for lower-capacity higher-resistance
batteries.
Or they knew, but were concerned about the reliability of electrolytic
capacitors. Modern electrolytics are merely bad -- back then they were
even worse! Note that a 20-year-old SCR controller still works; if they
had used electrolytics, it wouldn't!
Or, they knew and just wanted to save money.
You can add the filter capacitors yourself. You need to connect them as
close to the controller's input as you can, with as short and heavy a
wire as possible.
We don't have enough data to calculate a value, but it's going to take
thousands of microfarads. If it were me, I'd look for some surplus
electrolytics intended for switching power supply filtering, and put in
1,000uf worth. Measure your ripple current again, and see how much it
dropped. Then you can guess how much more it will take.
--
Ring the bells that you can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in
-- Leonard Cohen, from "Anthem"
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
Lawrence Rhodes wrote:
I have a 120v 20 battery pack. Weighs 1400 pounds. Lee recommended
1000uf and check again. What is the problem of putting in a few
thousand?
No direct harm; the more, the merrier.
However, the goal here is to reduce the battery ripple current. With
perfect zero-resistance capacitors, 1000uF is plenty because almost all
the controller's ripple current will then flow in the capacitors, not
the batteries.
However, real capacitors also have resistance, called ESR on the data
sheets (Equivalent Series Resistance). Capacitor ESR diverts ripple
current back to the batteries. ESR also produces heat, making the
capacitors get hot. It ultimately determines the maximum ripple current
that the capacitor can stand without overheating.
So, your goal is a capacitor with:
a. At least 1000uF of capacitance.
b. An ESR at least as low as your batteries ESR.
For example, an Optima has an ESR of about 0.003 ohms.
A pack of 10 has a total ESR of 10x0.003 = 0.03 ohms.
Add 20 connections at 0.001 ohm each = 0.05 ohms total.
So you want a capacitor with an ESR of 0.05 ohms or less.
c. A ripple current rating of at least 1/4th your motor current.
400 amp motor current means the controller is switching between
0 and 400, which is +/-200 amps peak AC ripple, which is about
100 amps RMS.
What you'll find is that its easy to find a 1000uF electrolytic
capacitor; but its ESR will be 1 ohm and its ripple current rating is
only 5 amps. Just one provides the capacitance, but you'd need 20 of
them in parallel to satisfy the ESR and ripple current requirements.
This is what you see in many controllers; a large number of cheaper
electrolytics, with far more capacitance than needed just to get the
ripple and ESR ratings.
Or, oil-filled paper or polypropylene film capacitors can easily meet
the ESR and ripple current requirements; but their capacitance is low. A
big metal can oil-filled capacitor can have 20uF of capacitance, 0.1 ohm
ESR, and a 25-amp ripple current rating. You'd need only 4 of them for
ESR and ripple, but 50 to get the capacitance. These capacitors would be
a lot larger and more expensive than electrolytics. So what you see in
some controllers are a smaller number of electrolytics (just to get the
capacitance), in parallel with a smaller number of oil or film
capacitors (to get the ESR and ripple ratings).
That's why I suggested that you experiment.
--
Ring the bells that you can ring
Forget your perfect offering
There is a crack in everything
That's how the light gets in
-- Leonard Cohen, from "Anthem"
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart
Lawrence Rhodes wrote:
Lee I hop I'm not bothering you too much but I didn't want to blow
anything up.
Aw, you're no fun! You should always have kids around when you blow up
capacitors. They enjoy the pyrotechnics. :-)
When you get an electrolytic capacitor that has been sitting unused for
a long time, you have to re-form its dielectric. Connect it to a high
voltage power source (like 150 vdc) with a resistor in series to limit
the current to no more than a few milliamps (like 100k ohms). Let it sit
until the capacitor voltage stops rising -- it will take 1-24 hours
depending on how long they have sat. If a capacitor won't rise to its
rated voltage without drawing more than 1 ma, consider it "bad".
You can also estimate their real capacitance at the same time. R x C is
the time constant -- the time it should take to charge to 2/3rds of the
applied voltage. 440uf x 100k = 44 seconds, so it should take 44 seconds
to charge to 2/3 * 150v = 100v. This will also weed out any bad ones.
These are the silver ones General Electric 92F311AMMA, 440UF -10+50%,
150vdc 200v surge, 85C Max Ambient. I got 10 of these. Should I put
them all on the positive or negative side or split them on each leg?
Do I have enough?
Put all of them in parallel, + to +, - to -. Since you're after the
lowest resistance, the usual method is to get two flat strips of copper
bus bar, drill holes for the capacitor's screws, and screw them to the
bar.
You connect the resulting "big" capacitor directly across the
controller's battery + and - inputs. Again, this should be done with
short, heavy wire or bus bars. If you don't have a precharge resistor,
you should add one; if the main contactor closes and tries to charge all
of these capacitors instantly, it will be murder on the contacts.
I described a method to find out how much/many capacitance is needed
based on the ripple current. Too few capacitors, and they will get hot
and not do much good. More is always better, but you reach a point where
the extra cost and weight isn't worth the slight improvement.
--
Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has! -- Margaret Mead
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
Lawrence Rhodes wrote:
So I put the plus buss bar on the positive end of the big capacitor
and the neg end of the big capacitor on the neg side of the pack.
Now I have the caps in parallel with the pack. Won't they just
charge by themselves now?
The capacitors connect directly across the CONTROLLER's B+ and B-
inputs, with the shortest fattest possible leads. The controller draws
pulses of current, and we want these pulses to come from the capacitors,
not the batteries.
I assume you have contactors, fuses, circuit breakers, a big disconnect
switch, or SOMETHING between the batteries and controller. That means
there will be times that one or more of these is open. When you close
it, the capacitors will try to charge INSTANTLY, leading to huge
currents which will damage the contacts of the last device to close. The
precharge resistor is intended to slowly charge the capacitors over a
second or two; then close the last switch.
like the air pocket used in water system to stop the pipes from
vibrating which I guess is what ripple current is.
Yes, it is basically the same thing that plumbers call "water hammer".
I'll try 10 caps and check for heat. Then I'll add more. I'll also
try weeding out the caps by charging with a variac.
...and a diode! Remember these are DC capacitors!
--
Humanity is acquiring all the right technology for all the wrong
reasons.
-- R. Buckminster Fuller
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
I know there was a discussion of the need to add vacuum back to one's
brakes after converting, and I had a good experience with upgrading
my vacuum pump to share.
my converted 85 mitsubishi truck had a small vacuum pump that drew
only 0.4 amps at 12 volts (I think it was designed for a soda
fountain or something). this pump hooked to an ABS reservoir that
hooked to the vacuum side of the brake assist.
the truck has 13 x 12v sealed batteries and is supposed to weigh less
than stock right now.
stopping the truck has always been a bit hair raising. it really
took a lot of force to stop the thing (and I am old enough to have
learned to drive on a car with manual brakes), and emergency stops
were often a lot closer to the next object than intended.
having read discussions on the list, I figured I was way under spec.
on my vacuum, so I shopped around and found a 12v vacuum pump for
about $65. it's lightly used and had attachments for medical suction
uses that I removed. I also found some vacuum switches on ebay for 4
for $25 and T'd one of those into the hoses as a shut off for the
pump @ about -24 mmHg.
I just got back from a neighborhood trip, the truck being offline due
to battery issues for months, and I was truly amazed at how quickly
it stopped. like a new vehicle.
my bottom line is that trying to emulate the stock vacuum assist is a
very good thing. and, since I'm probably going to 19 x 8v flooded,
increasing my weight by at least 400 pounds, once I test that the
motor's not going to melt, I am very very glad that I learned from
this list what the usual vacuum pumps pull for EVs.
thanks for the info. i'll be back with more questions soon.
and, thanks for all the rec's on the auto. watering systems. I am
getting bids on systems by flow-master, BFS, water master,
philadelphia scientific and aquapro. will let you all know how it goes.
elaine
berkeley, CA
--- End Message ---
--- Begin Message ---
This always puzzled me:
Lee Hart wrote:
If you want more horsepower (for climbing a hill or accellerating), a
96v pack only gives you one choice; upshift (like from 2nd to 3rd gear).
Note that this is the *opposite* of what you'd do with an ICE.
Upshifting slows the motor down, which makes it draw more current. For
2x the horsepower, you need 2x the current; 96v at 380 amps.
No, Lee, I think this is not correct. The power is torque * RPM,
and torque is current (~linear dependency), so when you upshift you
cause motor to draw twice as much current (produce twice torque)
but multiplied by half as much RPM now, it still totals the same power.
Look at it this way: twice as much torque with twice as tall
gear still produce the same torque at the wheels, so if you
slowing down uphill and upshift, you'll be still slowing down.
Now, if slowing motor twice (RPM) makes it draw 4x current, I can
understand that, and you indeed end up with twice as much HP,
but my impression was that this is more-less linear relationship.
Can you elaborate on this please?
Victor
--- End Message ---
--- Begin Message ---
Vicor 150:12v 100watt converters on Ebay right now...:
http://cgi.ebay.com/VI-251-CW-VICOR-INPUP-150-OUTPUT12_W0QQitemZ7605525794QQ
categoryZ4663QQrdZ1QQcmdZViewItem
--- End Message ---
--- Begin Message ---
Lee wrote:
> If you want more horsepower
More please. :)
>Up shifting slows the motor down
Indeed, but it also turns my gears slower. I want to keep the motor
at red line through every gear.
--- End Message ---
--- Begin Message ---
Osmo,
If you haven't done it yet, please download Siemens inverters
installation manual from Metric Mind web site - direct link
is http://www.metricmind.com/data/man_w.pdf
In the section describing testing you will see schematic of all the
connections completing drive system including fuse/circuit breaker
location.
But keep in mind, GFCI will belong to the charging system, not
drive system. There is no use for GFCI in an EV while in motion.
The GFCI choice depends on the type of charger you use. IF you have
isolated one and your pack is floating vs. chassy, chances are you
won't get any benefits of having GFCI. If you have non-isolated charger,
I'd say GFCI is mandatory.
Victor
Osmo S. wrote:
I´m trying to get the picture about the safety equipments needed for my
AC system. I haven´t chosen the batteries yet, but they will be about
300 V. Max DC current for my Siemens inverter is 280 A. I already got
main contactors along with the inverter.
Where can I find a good general schematic about power circuit, which
shows how to connect fuses, breakers etc? I´d like to do this as well as
possible, eliminating all the possible what-if scenarios. I´m thinking
of using an emergency switch and an inertial switch also.
Because of my limited english vocabulary, I´ve thought a circuit breaker
is the same as GFCI. But it´s not! :) More like a reusable fuse (with a
switch) switching off high current - not comparing current between hot
and neutral, right? So, I was wondering why you people use both fuses
AND circuit breakers, if they function in the same way. Why not use
fuses to limit current and a simple switch to manually switch off, or a
circuit braker alone to do the both? Just to double check?
Also, I haven´t seen any schematics or tutorials mentioning GFCI as a
safety device in ev. Why is that? Or have I just missed it?
Thanks,
Osmo
--- End Message ---
--- Begin Message ---
Jim Husted wrote:
If you pull your cover bands I might be able to see how she looks for you.
> I haven't seen one of those in like 17-18 years, hehe. Pretty cool
> stuff. Truly fun motors
Hey Jim and all-
I pulled the covers on the drive & pump motors and snapped a few more
pics. They're added at the bottom of the same page with the other photos:
http://www.metrompg.com/offsite/baker-motors.html
I'm not sure they show much detail, but I suspect you can identify
plenty of "detail" with a trained eye even in a bad photo.
The only tag i found on the drive motor is a service tag, I think. I
wrote down a few other numbers that are stamped into it, which I've also
listed on that page.
don't you ever just scrap those out or I'll have to come out and ...
That's a promise! (they were too much work to obtain to just scrap
'em!) It's as much fun reading your reaction to these things as it is
learning about what they are.
thanks -
Darin
--- End Message ---
--- Begin Message ---
Osmo,
See my schematic for how I connected up the VW with the Siemens system:
http://www.cameronsoftware.com/ev/EV_HighVoltageSystem.html
I used both a circuit breaker and fuses.
The circuit breaker is ued for two purposes:
1) a switch for turning the pack on and off
2) if an over current situation arises
In either case, the circuit breaker is wired so that when switch off no pack
is greater than 120VDC
I also use fuses one each pack as a backup.
A lot of this was designed from help from the EVDL (e.g. Victor, Lee, Roger,
Al, et al). I suggest you post a design, nd then let others help to refine
it.
Don
P.S. Have a circuit so if the charger is plugged in, I also have a few
other interconnect devices:
(a) if the charger is plugged in, the controller is turned off
Don Cameron, Victoria, BC, Canada
see the New Beetle EV project www.cameronsoftware.com/ev
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Osmo S.
Sent: April 3, 2006 10:05 AM
To: [email protected]
Subject: Circuit breakers, fuses, GFCI´s (newbie)
I´m trying to get the picture about the safety equipments needed for my AC
system. I haven´t chosen the batteries yet, but they will be about 300 V.
Max DC current for my Siemens inverter is 280 A. I already got main
contactors along with the inverter.
Where can I find a good general schematic about power circuit, which shows
how to connect fuses, breakers etc? I´d like to do this as well as possible,
eliminating all the possible what-if scenarios. I´m thinking of using an
emergency switch and an inertial switch also.
Because of my limited english vocabulary, I´ve thought a circuit breaker is
the same as GFCI. But it´s not! :) More like a reusable fuse (with a switch)
switching off high current - not comparing current between hot and neutral,
right? So, I was wondering why you people use both fuses AND circuit
breakers, if they function in the same way. Why not use fuses to limit
current and a simple switch to manually switch off, or a circuit braker
alone to do the both? Just to double check?
Also, I haven´t seen any schematics or tutorials mentioning GFCI as a safety
device in ev. Why is that? Or have I just missed it?
Thanks,
Osmo
--- End Message ---
--- Begin Message ---
On Mon, April 3, 2006 9:34 pm, Ryan Stotts said:
> A 2006 Chevy Aveo for ~$9,000 brand new and a 13" WarP for ~$4400 with
> a shaft sticking out both ends directly connected to stout aftermarket
> shafts that can "take it". Add in a ~$4800 Zilla and ~348+ volts of
> "something".
I don't know what any of my opinion about this subject is worth here
(possibly nothing), but I have a couple elements of concern about this.
First, take a look at the bare shaft that goes into that thing:
http://ohmbre.org/gallery/v/ConversionProject/Parts/motor/motor_shaft
Notice it's very one-sided. There's the stout end with the output spline
which is close to the armature stack, and the not-so-stout end for the fan
with the tailshaft, which is not as close to the armature. Getting both
ends to be as thick might be a bit of a manufacturing problem; at least it
seems like it might involve some retooling of the motor case. I'm no
expert at this, but maybe some other listers can weigh in. There's a
possibility it might not make any difference at all.
I know at least in Netgain's case a massive redesign of the shaft will
definitely spell [months-long] delays as they and Warfield's engineers
hash over the details.
> For the amount of money it's going to cost me to build an electric
> vehicle; I want it to be really, really fast for that type of money.
Then I'm going to guess that you really don't want to mess with a FWD
Aveo. I know there's been a lot of argument here on FWD/RWD/AWD before,
but if you want to try this kind of setup and let everyone know how it
goes, I'd say at least do it in the back of an MR2.
> And I want to be able to cruise it on the street(cause that is where
> all the fun is at!). Plus take it to the track to get some official
If you want to do it on the street though, good luck and even more
seriously consider RWD, because I think having the two drive wheels locked
together is going to make a short compact vehicle very hard to control.
> When is one of these 3, 13" powered mini trucks going to be ready!!?
> And what will they run in the 1/4?!
Well, as is pretty obvious from looking at my site, I've been doing a
whole lot of not working on my EV, and have been doing equal amounts of
letting people down and not following through on a bunch of other promises
I've made. Earlier this year my workload exploded (ultimately for which I
partially have myself to blame) and my almost fruitless 2 hours per week
on the truck has been framed pretty neatly by evenings and weekends spent
at the office. I'm looking forward to some drastic life changes that will
bring the light at the end of this tunnel, but I'm projecting that's at
least a month out.
On the other hand, it seems like Dennis has probably got his nearly
finished and on the road now ... what do you say, Dennis?
--chris
--- End Message ---
--- Begin Message ---
Dave Cloud did it many years ago in one of his race cars.
I will leave it to others who knew the car better to comment on how well it
worked.
Joe Smalley
Rural Kitsap County WA
Fiesta 48 volts
NEDRA 48 volt street conversion record holder
[EMAIL PROTECTED]
----- Original Message -----
From: "jmygann" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, April 03, 2006 11:45 AM
Subject: Dual Motors to FWD axles - Anyone done it ??
> Anyone know of a dual motor setup running directly to the FWD axles ??
>
> Maybe a single motor - dual shaft- direct to FWD axles ?
>
> Links ?? Issues ??
>
>
>
--- End Message ---
--- Begin Message ---
My High School EV program (Cortez High School, Phoenix AZ) had a Plymouth Laser
with dual 8" Advanced DC motors. The motors were mounted one in front of the
other connected by a belt drive connecting the tail shafts. I unfortunately
didn't get to play with this car much, but I do know some stress resulted in
the tail shaft snapping off of the front motor at one point requiring us to buy
a new one. We had the 96 volt pack of floodies in a T inside the passenger
compartment, very EV1 like. All that was under the hood was the motors,
controllers and other electrical components so it would create some nasty wheel
hop when you stood on it, but it was fun for showing off.
Later,
Ricky
02 Insight
92 Saturn SC2 EV 144 Volt
Glendale, AZ USA
---------------------------------
How low will we go? Check out Yahoo! Messengers low PC-to-Phone call rates.
--- End Message ---
--- Begin Message ---
Victor Tikhonov wrote:
> GFCI will belong to the charging system, not drive system. There is
> no use for GFCI in an EV while in motion.
This is true for the GFCI's in most hobby EVs. They are ordinary
household-type AC-only GFCI's that can't detect DC fault currents.
However, the EVs and hybrids produced by the auto companies *do* have
GFCI's that function when you are driving. They use special GFCI's that
sense both AC and DC fault currents. If there is a ground fault in the
DC propulsion system, this GFCI will detect it, and shut down the
vehicle. It's there for the same reasons they are used while charging;
to prevent shock hazard in case anyone manages to touch any of the
propulsion wiring, and to keep leakage currents from damaging components
from corrosion or shorts.
--
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 ---
But your Torque and Efficiency go down exponentially (square of the
rotational velocity) as your RPM goes toward redline.
Look at these curves for example for a Warp9
http://www.go-ev.com/images/WarP_9_Graph.jpg
Lets pick two points that show relatively easy comparisons (rounding wise)
from: to: If RPM goes:
RPM 4400 2200 down by a factor of 2
These go:
AMPS 110 330 up by by a factor of 3
H.P. 8 32 up by by a factor of 4
Torque 10 70 up by by a factor of 7
While the current to torque ratio is somewhat linear (directly related by
the armature constant Kt) the RPM to Torque curve is exponential.
If you are going up a hill and want to maintain speed, you need to upshift
to put more torque on the motor to draw more current from the batteries.
Otherwise, if you don't upshift your car will slow down to the RPM which
allows the torque and horsepower to maintain equilibrium. That RPM will be
the other direction from redline.
I don't have any experience driving an electric however. My inclination
though would be to let the car slow down in the same gear until I hit the
equilibrium point where lower speed and increased power points on the curve
come together. If I upshift as Lee suggests I could keep the speed the same
however I would be using a lot more energy at less efficiency moving uphill
at the same high speed. Think of it as luggin' in a diesel but a lot more
efficiently.
Mike
Anchorage, Ak.
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Ryan Stotts
Sent: Monday, April 03, 2006 7:44 PM
To: [email protected]
Subject: Re: Motor options
Lee wrote:
> If you want more horsepower
More please. :)
>Up shifting slows the motor down
Indeed, but it also turns my gears slower. I want to keep the motor
at red line through every gear.
--- End Message ---
--- Begin Message ---
Lee Hart <[EMAIL PROTECTED]> wrote:
However, the EVs and hybrids produced by the auto companies *do* have GFCI's
that function when you are driving. They use special GFCI's that sense both AC
and DC fault currents. If there is a ground fault in the DC propulsion system,
this GFCI will detect it, and shut down the vehicle. It's there for the same
reasons they are used while charging; to prevent shock hazard in case anyone
manages to touch any of the propulsion wiring, and to keep leakage currents
from damaging components from corrosion or shorts.
Was this done for actual leakage currents or anticipated ones? If actual,
what are their sources/causes? Why not just build architecture so the leakage
currents don't manifest?
Mark
---------------------------------
Yahoo! Messenger with Voice. PC-to-Phone calls for ridiculously low rates.
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
>> If you want more horsepower (for climbing a hill or accellerating),
>> a 96v pack only gives you one choice; upshift (like from 2nd to 3rd
>> gear). Note that this is the *opposite* of what you'd do with an ICE.
>> Upshifting slows the motor down, which makes it draw more current.
>> For 2x the horsepower, you need 2x the current; 96v at 380 amps.
Victor Tikhonov wrote:
> No, Lee, I think this is not correct. The power is torque * RPM,
> and torque is current (~linear dependency)
Not in a series motor. Torque is proportional to current *SQUARED*. In
practice, it's somewhat less at high current as the iron starts to
saturate, but torque still goes up faster than current.
> when you upshift you cause motor to draw twice as much current
> (produce twice torque) but multiplied by half as much RPM now, it
> still totals the same power.
Look at the situation I was describing. You are trying to accellerate
your 96v EV with a series motor. You're in 2nd gear, and have the
accellerator floored. At some fairly low motor speed, the controller
comes out of current limit; the motor is getting 100% of the pack
voltage, and the motor current is below the controller's current limit
and falling. For the numbers I gave (96v at 190 amps), the 9" ADC will
be at about 2700 rpm.
So you UPshift. Yes, this slows the motor down. But it makes the motor
current go UP. If you don't slow it so much that the controller goes
into current limit, then you have GAINED horsepower. For the example I
gave, upshifting changed the motor from 96v x 190a = 18.24kw to 96v x
380a = 36.48kw. This is 2x the watts in, so (approximately) 2x the
horsepower out.
Now, if you shifted to too high a gear, (from 2nd to 4th gear, for
example), then you slow the motor so much that the controller goes into
current limit and reduces the voltage. The motor might go from 190a to
500a, but the voltage dropped from 96v to 48v because the controller is
at a 50% duty cycle. 48v x 500a = 24kw, which is LESS horsepower.
--
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 ---
>> Up shifting slows the motor down
Ryan Stotts wrote:
> Indeed, but it also turns my gears slower. I want to keep the motor
> at red line through every gear.
Not with a series motor! You get the LEAST torque and LOWEST horsepower
at the motor's redline. With a series motor, you want to load it down
until its current is at the controller's current limit. That is the
point of peak horsepower.
--
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 <[EMAIL PROTECTED]> wrote:
>> the EVs and hybrids produced by the auto companies *do* have GFCI's
>> that function when you are driving... If there is a ground fault in
>> the DC propulsion system, this GFCI will detect it, and shut down
>> the vehicle.
Mark Freidberg wrote:
> Was this done for actual leakage currents or anticipated ones?
> If actual, what are their sources/causes? Why not just build
> architecture so the leakage currents don't manifest?
The goal is always to build so the leakage current is as close to zero
as possible. Leakage currents create a shock hazard, increase noise,
promote corrosion, and add stress to components.
The DC GFCI's are there to detect leakage current, as a predictor of
trouble. The source of the leakage current could be someone touching the
high voltage DC wiring and ground, a leaky or dirty battery, water
getting into some part of the HV system, insulation breakdown somewhere,
etc. All of these indicate trouble!
--
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 <[EMAIL PROTECTED]> wrote:
The source of the leakage current could be someone touching the high voltage DC
wiring and ground, a leaky or dirty battery, water getting into some part of
the HV system, insulation breakdown somewhere, etc.
A leaky battery as in a flooded battery with wet exterior? Any other way a
battery, sealed or not, would be leaky?
Could inductance be a source of leakage currents? That is, flow thru one wire
induces flow thru another wire that would otherwise not have any current
flowing thru it?
Are all the causes of leakage currents known and understood (by someone or
collectively)?
Mark
---------------------------------
Yahoo! Messenger with Voice. PC-to-Phone calls for ridiculously low rates.
--- End Message ---
--- Begin Message ---
On Apr 3, 2006, at 6:51 PM, [EMAIL PROTECTED] wrote:
I never meant to create such a heated discussion concerning
performance of
EVs. All I wanted to do was get a reality check on my design before I
started
putting the dollars on the table. And, I did get that end result.
And, I
think some others on the list also got a better understanding of what
to expect
from such a design.
[snip good stuff]
Thanks again for all the insight,
Steve
I just wanted to say that you have posted a great compliment to the EV
list. Some people who find out what they don't want hear get huffy
and/or decide they know better than the vast range of EV experience
represented on the list. To listen, even though it messes with your
ideas, was the first compliment. To provide such a good outline, that
will likely be pulled up by other new members when searching the
archives, was a second. I hope you choose to stick around.
Thank *you* Steve,
Paul "neon" G.
--- End Message ---
--- Begin Message ---
On Apr 3, 2006, at 7:34 PM, Ryan Stotts wrote:
A 2006 Chevy Aveo for ~$9,000 brand new and a 13" WarP for ~$4400 with
a shaft sticking out both ends directly connected to stout aftermarket
shafts that can "take it". Add in a ~$4800 Zilla and ~348+ volts of
"something".
Uhmm, I car that will go strait almost regardless of how you turn the
steering wheel. A front wheel drive vehicle *really* needs some type of
differential. Even a RWD vehicle is not that street-able with a spool
(try nailing the throttle in a corner.)
Paul "neon" G.
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
Victor Tikhonov wrote:
GFCI will belong to the charging system, not drive system. There is
no use for GFCI in an EV while in motion.
This is true for the GFCI's in most hobby EVs. They are ordinary
household-type AC-only GFCI's that can't detect DC fault currents.
However, the EVs and hybrids produced by the auto companies *do* have
GFCI's that function when you are driving. They use special GFCI's that
sense both AC and DC fault currents. If there is a ground fault in the
DC propulsion system, this GFCI will detect it, and shut down the
vehicle. It's there for the same reasons they are used while charging;
to prevent shock hazard in case anyone manages to touch any of the
propulsion wiring, and to keep leakage currents from damaging components
from corrosion or shorts.
Lee, I was referring to Osmo's vehicle with Siemens AC system -
he will not have GFCI you describe. But thanks for the info!
Victor
--- End Message ---
--- Begin Message ---
Just for kicks let me throw in this simplistic idea, how about 1 electric
motor directly linked to 1 front wheel by cv shaft and let the other front
tire free wheel like the rears do. How would this work for a normal low
powered street car. Mike Young
----- Original Message -----
From: "Paul G." <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, April 04, 2006 2:21 AM
Subject: Re: Dual Motors to FWD axles - Anyone done it ??
>
> On Apr 3, 2006, at 7:34 PM, Ryan Stotts wrote:
>
> > A 2006 Chevy Aveo for ~$9,000 brand new and a 13" WarP for ~$4400 with
> > a shaft sticking out both ends directly connected to stout aftermarket
> > shafts that can "take it". Add in a ~$4800 Zilla and ~348+ volts of
> > "something".
> >
>
> Uhmm, I car that will go strait almost regardless of how you turn the
> steering wheel. A front wheel drive vehicle *really* needs some type of
> differential. Even a RWD vehicle is not that street-able with a spool
> (try nailing the throttle in a corner.)
>
> Paul "neon" G.
--- End Message ---
--- Begin Message ---
Thanks all for your help
i'm witness of their wonderful service: i'm over the pond and they exchange
my old never used "never connect it to a Lynch" motor controller for a new
"Lynch motor suitable" controller which is working great :^)
I already asked theim and know i will have an answer but i asked list help
also as i was in a hurry because of...ebay opportunity :^)
will quietly wait the answer and open this motor to see how it's wired.
cordialement,
Philippe
Et si le pot d'échappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
Forum de discussion sur les véhicules électriques
http://vehiculeselectriques.free.fr/Forum/index.php
----- Original Message -----
From: "Bob Bath" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, April 04, 2006 12:57 AM
Subject: Re: Need help about sepex Motor and alltrax DCX please
> Bonjour, Phillipe,
> As DCP/AllTrax lives in my town, I can assure you
> that the founder can take time away from 30 or so
> employees and be happy to answer that question. Try
> 541.476.3565!
>
>
> --- Jim Husted <[EMAIL PROTECTED]> wrote:
>
> > Hey Philippe
> >
> > First off I've never seen that motor before but I
> > do 3 terminal motors made by Lansing. They do this
> > by winding eachcoils with two wires, but after the
> > coil is complete they separate the two wires leaving
> > 4 connections at each coil. This causes every other
> > winding of each col to be the opposite polarity.
> > They connect the coils to the inside connected brush
> > lead opposite the "A" terminal you see.
> > You just switch the power cable between the 2) "A"
> > terminals to reverse rotation, so the field
> > connection always stays connected to batteries, or
> > controller. So once you determine what direction
> > you need, just look at the motor as only a two
> > terminal motor. As to how to sep-ex it I'll leave
> > that to those who know. I'm just the resident motor
> > dork 8^P
> > Hope this helps
> > Jim Husted
> > Hi-Torque Electric
> >
> > Philippe Borges <[EMAIL PROTECTED]> wrote:
> > Hello,
> >
> > I heard about alltrax DCX series controler made for
> > golf cart sepex motors.
> > They have 2 armatures and 2 field connections
> > I have a "special?" sepex motor which has only 3
> > wires (A1-A2-field) and i
> > don't know how it's wired internaly
> > picture here:
> >
> http://vehiculeselectriques.free.fr/images/Scootelecmoteur.jpg
> >
> > Do you think DCX can control it? if so what will be
> > the wiring ?
> > thanks for your help
> >
> > cordialement,
> > Philippe
> >
> > Et si le pot d'échappement sortait au centre du
> > volant ?
> > quel carburant choisiriez-vous ?
> > http://vehiculeselectriques.free.fr
> > Forum de discussion sur les véhicules électriques
> > http://vehiculeselectriques.free.fr/Forum/index.php
> >
> >
> > ----- Original Message -----
> > From: "Bob Rice"
> > To:
> > Sent: Monday, April 03, 2006 7:15 PM
> > Subject: Re: Motor options
> >
> >
> > >
> > > ----- Original Message -----
> > > From: "David Roden"
> > > To:
> > > Sent: Monday, April 03, 2006 3:19 AM
> > > Subject: Re: Motor options
> > > Hi EVerybody;
> > >
> > > I gotta dive in on this one! John didn't EVen
> > mention the Diseasel
> > > Rabbit, which makes the GAS one look like a
> > fireball! The Diseasel has a
> > > romping,stomping 40 hp, never timed it, although
> > it was suggested to use a
> > > sundial!It got Jerry to Fla from CT towing a
> > Sunrise body on a trailer
> > > and averaged in the hy thirties, miliage wise. He
> > was happy with it!
> > >
> > > > On 2 Apr 2006 at 22:18, John Wayland wrote:
> > > >
> > > > > The stock 1981 Rabbit weighs 1775 lbs., has 74
> > hp, and takes 12.6
> > > > > l-o-n-g seconds to get to 60 mph.
> > >
> > > > I think 60 in the twelves is not bad, for a
> > TRAIN! All kidding aside I
> > > lived with the Diesel one and was happy with it.
> > Getting better miliage
> > than
> > > Prei, but not as good as a Insite,It was easy to
> > fix, parts anywhere. I
> > used
> > > to say that ya needed an apointment to get on the
> > turnpike with it, but if
> > > you planned ahead, a little, an alian concept ,in
> > driving you'd be OK.
> > > > L-o-n-g? Maybe to John, but that sounds plenty
> > fast to me.
> > > >
> > > > I don't want to get too involved in this
> > exchange, but I do want to
> > point
> > > > out to both parties that "fast" and "slow" mean
> > different things to
> > > > different people.
> > > >
> > > > John would find the Solectria Force's
> > acceleration excruciating.
> > >
> > > I did, to, the Rabbit would blow the doors off the
> > Force, to quote
> > > John!With my blistering 54 in the Quarter at Power
> > of DC he needent be
> > > looking in his rear view mirror. With my recent
> > upgrades , T Wrecks
> > > controller, stouter clutch, and T 145's I may
> > break 60 in the quarter. Do
> > I
> > > care? Really, Yes I want a bit more OOOMPH, but
> > I'm happy with my glatial
> > > performane, when I can drive it EVery day, as a
> > useful vehicle.Doing
> > > conversions is an excersize in masochism, anyhow.
> > Looking forward to
> > > Freedoms or, Gasp! A Sunrise, someday.Purpose
> > built EV's. A 3100 lb Rabbit
> > > isn't the way to go, but what ELSE in the small
> > car line nowadaze offers a
> > > reasonable tradeoff for conversions??
> > >
> > > In fact,
> > > > I'm pretty sure he's said something along those
> > lines in the past. But
> > > > that's OK; I don't offend easily. His opinion of
> > the car doesn't harm
> > me
> > > > one bit, and he has a way with words that I find
> > entertaining. (Some
> > > others
> > > > do, some don't. Some chuckle when he refers to
> > their cars as slugs;
> > others
> > > > get annoyed. So it goes.)
> > >
> > > > I love John's posts from Wacky Raccoons to
> > theWhite Zombie story, the
> > > shared adventures at the Track. I have been there,
> > too. Or WHY I drive out
> > > to PDX EVery year to do Woodburn. Racing is silly,
> > but it sure advances
> > the
> > > EV Tech dept. Having Jim Husted come aboard of
> > late. Heres a knowledgeable
> > > cool guy, Hotrodding motors, getting the best and
> > most out of our poor
> > > tortured motors. He should build and sell the
> > Siamese line of Racing
> > motors,
> > > to others that want to get down the track, FAST!
> > >
> > > > In fact John's opinions tell me a fair bit about
> > John, which allows me
> > to
> > > > better evaluate how his views might apply to my
> > needs - a good thing.
> > His
> > > > comments on the VoltsRabbit suggest to me me
> > that I'd probably find one
> > > > entirely adequate. That's nice to know. ;-)
> > >
> > > > And alota stuff we ALL can know and use on the
> > List.David? Ya gotta come
> > > to the Races! This year??
> > >
> > > Seeya at the races
> > >
> > > Bob
> > >
> >
> >
> >
> >
> > ---------------------------------
> > Yahoo! Messenger with Voice. PC-to-Phone calls for
> > ridiculously low rates.
> >
> >
>
>
> '92 Honda Civic sedan, 144V (video or DVD available)!
> www.budget.net/~bbath/CivicWithACord.html
> ____
> __/__|__\ __
> =D-------/ - - \
> 'O'-----'O'-'
> Would you still drive your car if the tailpipe came out of the steering
wheel? Are you saving any gas for your kids?
>
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