EV Digest 6062
Topics covered in this issue include:
1) GE at EDTA Electric Vehicle Conference
by "Mark E. Hanson" <[EMAIL PROTECTED]>
2) Re: Not getting any evdl posts
by Dave Cover <[EMAIL PROTECTED]>
3) I'm finally getting messages again
by Jim Husted <[EMAIL PROTECTED]>
4) Re: EV controllers? the 4th option...
by Chet Fields <[EMAIL PROTECTED]>
5) Curtis 1231C at 158V?
by [EMAIL PROTECTED]
6) Re: EV digest 6059
by [EMAIL PROTECTED]
7) RE: Cursit controllers revisited (squealing); precharge 'circuit' again
(please)
by "Hartsell, Fred" <[EMAIL PROTECTED]>
8) Re: EV digest 6059
by "Bill Dennis" <[EMAIL PROTECTED]>
9) Re: dc-dc working
by Lee Hart <[EMAIL PROTECTED]>
10) Re: Battery Chargers
by Lee Hart <[EMAIL PROTECTED]>
11) Re: Cursit controllers revisited (squealing); precharge 'circuit'
again (please)
by Lee Hart <[EMAIL PROTECTED]>
12) Re: Cursit controllers revisited (squealing); precharge 'circuit'
again (please)
by Lee Hart <[EMAIL PROTECTED]>
13) RE: I'm finally getting messages again
by "Myles Twete" <[EMAIL PROTECTED]>
14) Power Battery
by Jeff Major <[EMAIL PROTECTED]>
15) Re: EV controllers? the 4th option...
by "Peter VanDerWal" <[EMAIL PROTECTED]>
16) Any EV Listers from New Mexico?
by "Roderick Wilde" <[EMAIL PROTECTED]>
17) OT Re: Not getting any evdl posts
by Lock Hughes <[EMAIL PROTECTED]>
18) Re: OT Re: Not getting any evdl posts
by "David Roden" <[EMAIL PROTECTED]>
19) RE: Cursit controllers revisited (squealing); precharge 'circuit' again
(please)
by "Roger Stockton" <[EMAIL PROTECTED]>
20) Re: OT Re: Not getting any evdl posts
by Dave Cover <[EMAIL PROTECTED]>
21) Re: Inexpensive DC Motors with Keyed Shafts
by "Bruce" <[EMAIL PROTECTED]>
22) RE: Cursit controllers revisited (squealing); precharge 'circuit' again
(please)
by "Roger Stockton" <[EMAIL PROTECTED]>
23) Dual motors with "hopped up Curtis" - seires or parallel?
by Steve Condie <[EMAIL PROTECTED]>
24) Re: Inexpensive DC Motors with Keyed Shafts
by Eric Poulsen <[EMAIL PROTECTED]>
25) Re: Inexpensive DC Motors with Keyed Shafts
by "Peter Gabrielsson" <[EMAIL PROTECTED]>
26) Re: Inexpensive DC Motors with Keyed Shafts
by "Peter Gabrielsson" <[EMAIL PROTECTED]>
27) Splined Adapters, Was: Inexpensive DC Motors with Keyed Shafts
by "Bruce" <[EMAIL PROTECTED]>
28) Re: OT Re: Not getting any evdl posts
by "David Roden" <[EMAIL PROTECTED]>
29) RE: Cursit controllers revisited (squealing); precharge 'circuit'
again (please)
by Cor van de Water <[EMAIL PROTECTED]>
--- Begin Message ---
Hi,
I noticed on www.electricdrive.org/conference 2006/ that GE (number 200) has
a display listed as www.geplastics.com . I was curious if anyone knew if they
are getting back into EV's under the GE Plastics division. It's Tuesday NOV 28
- Thursday Nov 30th in Washington DC.
I'm taking my boy to Myrtle Beach Thanksgiving week and my vacation time
will be used up, otherwise I'd go & do a report.
Have a renewable energy day,
Mark
---------------------------------
Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates
starting at 1¢/min.
--- End Message ---
--- Begin Message ---
Me either. Non-EVlist emails were coming through. And other Yahoo group emails.
But nothing from
the SJSU list. They are jsut starting to come through this morning (Wednesday.)
Dave Cover
--- Storm Connors <[EMAIL PROTECTED]> wrote:
> I got no posts either.
>
> ----- Original Message ----
> From: Cor van de Water <[EMAIL PROTECTED]>
> To: [email protected]; Jim Husted <[EMAIL PROTECTED]>
> Sent: Tuesday, October 24, 2006 1:39:25 AM
> Subject: RE: Not getting any evdl posts
>
> Jim,
>
> your post was nr 53 today, by my count.
> If your email program or service provider has an
> issue so the posts cannot be delivered to you, then
> you will receive all the posts 2 days later
> is my experience.
>
> Regards,
>
> 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 Jim Husted
> Sent: Monday, October 23, 2006 10:16 PM
> To: EVDL
> Subject: Not getting any evdl posts
>
>
> Hey all
>
> Not sure whats going on now but I didn't recieve a
> single EVDL post today. I know there were some by
> going to the archieves. Yahoo's been slower than
> normal today but I've gotten privates and test mails.
>
> Anyway is there a way to check to see if it's Yahoo or
> a glitch toward me getting it from the list??
>
> Meanwhile I'll surf the stuff manually untill I figuer
> out what the heck is going on.
>
> Anyone else having, seeing anything like this??
>
> It's been several days since I changed to text only so
> it can't be related, being everything was working
> fine.
> Thanks
> Jim
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>
>
>
>
>
--- End Message ---
--- Begin Message ---
Hey all
Looks like the logjam is breaking up and I got some
messages rolling in here again. Thanks to all that
offered help but it looks like it was some kind of
glitch. Cor wrote me and said wait 2 days and they'll
come through and well he was right (thanks Cor)
They are not yet caught up but I'm getting them in at
least. Good thing being I was starting to detox from
lack of EVDL injections, LMAO!
Cya
Jim Husted
Hi-Torque Electric
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
--- Matthew Milliron <[EMAIL PROTECTED]> wrote:
> On Sun, 22 Oct 2006 02:16:13 -0400, you wrote:
>
> >Curtis controllers are more like Ford Escorts than BMWs.
>
> Hay! There is nothing wrong with Ford Escorts! <GRIN>
Especially when they are electric! ;) or EVCorts!
Speaking of EVCorts and DC EV Controllers, a list member was able to supply me
a copy of the schematics for the motor controller for my EVCort (which
unfortunately went south for the winter).
It is a Sep Ex controller 108V/400A. It has up to 200A regen, slow on fast off,
limits the current on low voltage, limits the max current, adjustable regen
voltage and current, adjustable 'exhaust brake' feature. It uses a GE 40kw
motor with separate field windings. And of course it is DC.
In all of this discussion of open DC Controllers and how also the desire for
regen and so on, I was thinking, Well, it has been done, I have it right here
in my garage and the design is actually about 15 - 20 years old.
If it was redesigned to use modern components it could probably be alot smaller
and lighter. (It is about 1'x1'x3' with the huge heat sink and must weigh close
to 100lbs.) And could even have higher voltage/amperage levels.
It does have 4 chopper circuits though, besides the other controll circuitry,
and banks and banks of paralleled power transistors. I suppose it really is
tens of thousands of dollars of engineering as these vehicles were provided as
EV studies, especially for the batteries, and built as part of a DOE program.
But now that the company that built them no longer exists (Soleq) and the chief
engineer has passed away, could anything be done with the designs?
Regards,
Chet
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Forgot the subject for the previous post.
Rod
--- End Message ---
--- Begin Message ---
Does anyone know if it is possible to drive a Curtis 1231C at 158V nominal?
I am looking at using Lithium Ion batteries with my Zivan NG3 charger which
would mean that after the peak charging voltage of 172.8V the pack would settle
back to 158.4V float.
>From experience with my PbAcid pack the voltage actually goes much higher than
that when charging and first starting up. There have been times when I have
forgotten to switch the car off before charging and the pack voltage rose to
198V without cooking the Curtis.
I am just wondering if the Curtis could handle higher than 144V continuously
while driving.
Regards, Rod Dilkes
www.dilkesmotors.com
--- End Message ---
--- Begin Message ---
Ok, I am trying to get a handle on this pre-charge circuit since I am
wiring up my Dodge Dakota conversion for the first time. I am a newbie
at this and I have been reading these post as well as the book "Building
your own Electric Vehicle" by Bob Bryant. I have also downloaded the
complete manual for my Curtis 1231C control from the Curtis website. So
now I have some question for you experts out there so that I won't get
any surprises.
1. On page 9, figure 8 of the Curtis manual, it shows a pre-charge
resistor in place on the Main contactor but on page 150, figure 10-7, of
the Build your own EV book, it does not show the pre-charge resistor.
Which is the preferred method?
2. Also both diagrams show different ways of activating the Main
contactor; the Curtis manual uses the n.c. switch on the Throttle pot to
activate the main contactor using the 12vdc key switch then the pack
voltage is sent through a KSI relay to the controller. The book uses the
key switch 12 vdc supply to activate the main contactor and then the
pack voltage is fed to the n.c. switch on the throttle pot and then to
the controller. Which is the preferred method?
Please pardon me if I am confused on this subject. As I said earlier
this is my first conversion.
Thanks,
Fred
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Cor van de Water
Sent: Wednesday, October 25, 2006 2:18 AM
To: [email protected]
Subject: RE: Cursit controllers revisited (squealing); precharge
'circuit' again (please)
Roger wrote:
> When you first get in the car, the controller caps are discharged and
> appear as essentially a dead short. If you simply close the main
> contactor and apply full pack voltage to the controller, the inrush
> current can be *huge* (as in 100s of amps).
Make that thousands of amps.
Most batteries have a series resistance of a few milli-Ohm,
mine have 4 mOhm for a 12V battery.
When I dead-short then with capacitors, the initial burst
will start at 12V/4mOhm = 3000 Amp.
Usually a contactor is not closing its contacts completely
when first pulled it, they first "bounce" a little due to the
speed and mass with which they hit each other. After many
milliseconds they stop bouncing, like a steel ball dropped
on the floor when you push it down stops bouncing quickly,
but the contacts will be damaged if they are required to
bounce while carrying 3000 Amps.
Soon they will either weld shut (you can't turn the car off)
or they will not "make" reliably due to crud built up
between the contacts and they may burn up or flake, so
you won't be able to drive.
The precharge uses a resistor to control the current flowing
into the capacitors to usually just a few amps.
Within a second usually the capacitors are charged to a high
enough voltage that closing the main contactor will not
cause a large current flow, because the voltage difference
has become small.
Hope this clarifies,
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
--- End Message ---
--- Begin Message ---
I asked this question last year, and the answer was that the Curtis can
handle around 172V - 180V peak. So it sounds like you should be okay.
Bill Dennis
[EMAIL PROTECTED] wrote:
Does anyone know if it is possible to drive a Curtis 1231C at 158V nominal?
I am looking at using Lithium Ion batteries with my Zivan NG3 charger which
would mean that after the peak charging voltage of 172.8V the pack would settle
back to 158.4V float.
>From experience with my PbAcid pack the voltage actually goes much higher than
that when charging and first starting up. There have been times when I have
forgotten to switch the car off before charging and the pack voltage rose to
198V without cooking the Curtis.
I am just wondering if the Curtis could handle higher than 144V continuously
while driving.
Regards, Rod Dilkes
www.dilkesmotors.com
--- End Message ---
--- Begin Message ---
David wrote:
> "Since the supply is being used on pure DC, could the filters be
> safely removed or disconnected?"
You could significantly reduce their capacitance (say, 100:1) but not
eliminate them entirely. The capacitors are a necessary part of a DC/DC
converter. Every DC/DC needs at least 1 transistor, 1 diode, 1 inductor,
and 1 capacitor.
If you change the capacitor, use film capacitors instead of
electrolytics. Film capacitors have a much lower internal resistance,
and are much better at suppressing noise. For example, replace a 470uF
200vdc electrolytic with a 4.7uF 600v polypropylene film capacitor.
--
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:
I have a couple of radio shack data logging meters. I just hooked
them up to monitor voltage and current (through a shunt), recorded
it on the computer, then plotted the results.
Mike Sandman wrote:
Cool. I have a instrumentation/controller project in the works using
the *Make Controller* board, so I should be able to add some charging
monitoring (data logging) to this.
You don't need fancy equipment to check a charger's charging algorithm.
Just an ammeter and voltmeter and clock. Things happen so slowly that
you can just measure the voltage and current every hour or so, and plot
them on a piece of paper yourself.
In 90% of the chargers, you'll find that they are just a taper charger
(equivalent to a transformer-rectifier), no matter what the marketing
claims. In other words, they only deliver their advertised current into
a totally dead battery, and it tapers down throughout the charge cycle
(i.e. there is no "constant current" mode). And, it either chargers
blindly forever, or shuts off at some arbitrary and rather poorly
controlled voltage or current (i.e. there is no "constant voltage"
finishing mode).
--
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 ---
Seth Myers wrote:
1. Curtis squealing:
- mounting the controller on a non-conductive MDO or MDF board
(form of plywood), 4 bolts, resulted in minimal squeal (0-3 mph)
Roger Stockton wrote:
the vast majority of the noise comes from the motor, not the controller
also seems like a particularly poor design decision as MDO/MDF provides
absolutely no heatsinking for the poor Curtis...
I agree. The controller is your "amplifier", and the motor is your
"speaker". It's the motor you want to muffle, not the controller.
Roger's heatsink advice is also right on; mount the controller to metal,
not wood!
The Curtis has a particularly poor thermal design, so I would expect
these hopped-up controllers to offer little if any benefit in the
real world... there isn't space to add much more bus caps...
Again, I agree. Just sticking bigger MOSFETs in the case isn't really a
good fix. To properly beef it up, you'd have to replace the whole power
section, and I doubt they do that. It would be cheaper to start over
from scratch.
We do not use the precharge resistor because it would always
energize the controller.
I start to question the credibility of this converter ;^>
Same here! Going without a precharge resistor is murder on the main
contactor, and will kill the controller's capacitors in the long run.
--
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 ---
Dave Wilker wrote:
What about using Inductors to delay the current, and Caps to delay Voltage?
The controller needs the lowest possible impedance on its input. The
lower the impedance, the less ripple current the batteries see, and the
lower the voltage spikes on the MOSFETs or IGBTs.
If you add series inductance to the batteries, it helps the batteries
but the capacitors are forced to do the whole job themselves. Thus, you
need more/bigger/more expensive capacitors.
--
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 ---
> Thanks to all that offered help but it looks like it was some kind of
glitch.
Hardly a glitch---it was systemic: all you who noted you weren't getting
email from the list had YAHOO email addresses.
That's not a glitch.
-MT
--- End Message ---
--- Begin Message ---
Danny,
I have not used the product myself, but did visit a company using the Power
Battery TL series (telecom) batteries in high quality UPS products. They
thought it was a good battery and $, but they were buying bunches.
I have used some other brand telecom SLA batteries in smaller vehicles with
good results so far (1 to 2 years of occasional use). They seem to be a lot
less expensive than Optimas and Hawkers and the like, although not rated for
vehicle use. I have no idea if they would stand up to highway vibration or
cycle life. My applications were in the 10 to 20 mph range.
Jeff
Danny Miller <[EMAIL PROTECTED]> wrote:
Say, anybody know about Power Battery?
http://www.powerbattery.com/products/Solar%20Series.htm
I actually just need a deep cycle for my regular van's accessories, and
the "Solar" series has some pretty good ratings as far as cycle life and
Peukert's coefficient. They do have a "marine" line which seems
designed for high starting current, but they didn't describe the cycle life.
Danny
---------------------------------
Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates
starting at 1¢/min.
--- End Message ---
--- Begin Message ---
Do you have a source for affordable, EV size, SepEX motors?
The controller is not much good without them.
>
> --- Matthew Milliron <[EMAIL PROTECTED]> wrote:
>
>> On Sun, 22 Oct 2006 02:16:13 -0400, you wrote:
>>
>> >Curtis controllers are more like Ford Escorts than BMWs.
>>
>> Hay! There is nothing wrong with Ford Escorts! <GRIN>
>
> Especially when they are electric! ;) or EVCorts!
>
> Speaking of EVCorts and DC EV Controllers, a list member was able to
> supply me
> a copy of the schematics for the motor controller for my EVCort (which
> unfortunately went south for the winter).
>
> It is a Sep Ex controller 108V/400A. It has up to 200A regen, slow on fast
> off,
> limits the current on low voltage, limits the max current, adjustable
> regen
> voltage and current, adjustable 'exhaust brake' feature. It uses a GE 40kw
> motor with separate field windings. And of course it is DC.
>
> In all of this discussion of open DC Controllers and how also the desire
> for
> regen and so on, I was thinking, Well, it has been done, I have it right
> here
> in my garage and the design is actually about 15 - 20 years old.
>
> If it was redesigned to use modern components it could probably be alot
> smaller
> and lighter. (It is about 1'x1'x3' with the huge heat sink and must weigh
> close
> to 100lbs.) And could even have higher voltage/amperage levels.
>
> It does have 4 chopper circuits though, besides the other controll
> circuitry,
> and banks and banks of paralleled power transistors. I suppose it really
> is
> tens of thousands of dollars of engineering as these vehicles were
> provided as
> EV studies, especially for the batteries, and built as part of a DOE
> program.
>
> But now that the company that built them no longer exists (Soleq) and the
> chief
> engineer has passed away, could anything be done with the designs?
>
> Regards,
> Chet
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>
>
--
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 ---
I have been contacted by a woman in Cleveland, New Mexico interested in
purchasing an EV. If you are knowledgeable about EVs and wish to help her
and you are in the area please contact me off list and I'll give you contact
info.
Roderick Wilde
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.408 / Virus Database: 268.13.11/496 - Release Date: 10/24/2006
--- End Message ---
--- Begin Message ---
Just wanted to point out, seems like all the folks who were in
withdrawal have yahoo addresses
tks
Lock
Toronto
Human/Electric Hybrid
--- Dave Cover <[EMAIL PROTECTED]> wrote:
> Me either. Non-EVlist emails were coming through. And other Yahoo
> group emails. But nothing from
> the SJSU list. They are jsut starting to come through this morning
> (Wednesday.)
>
> Dave Cover
>
> --- Storm Connors <[EMAIL PROTECTED]> wrote:
>
> > I got no posts either.
> >
> > ----- Original Message ----
> > From: Cor van de Water <[EMAIL PROTECTED]>
> > To: [email protected]; Jim Husted <[EMAIL PROTECTED]>
> > Sent: Tuesday, October 24, 2006 1:39:25 AM
> > Subject: RE: Not getting any evdl posts
> >
> > Jim,
> >
> > your post was nr 53 today, by my count.
> > If your email program or service provider has an
> > issue so the posts cannot be delivered to you, then
> > you will receive all the posts 2 days later
> > is my experience.
> >
> > Regards,
> >
> > 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 Jim Husted
> > Sent: Monday, October 23, 2006 10:16 PM
> > To: EVDL
> > Subject: Not getting any evdl posts
> >
> >
> > Hey all
> >
> > Not sure whats going on now but I didn't recieve a
> > single EVDL post today. I know there were some by
> > going to the archieves. Yahoo's been slower than
> > normal today but I've gotten privates and test mails.
> >
> > Anyway is there a way to check to see if it's Yahoo or
> > a glitch toward me getting it from the list??
> >
> > Meanwhile I'll surf the stuff manually untill I figuer
> > out what the heck is going on.
> >
> > Anyone else having, seeing anything like this??
> >
> > It's been several days since I changed to text only so
> > it can't be related, being everything was working
> > fine.
> > Thanks
> > Jim
> >
> > __________________________________________________
> > Do You Yahoo!?
> > Tired of spam? Yahoo! Mail has the best spam protection around
> > http://mail.yahoo.com
> >
> >
> >
> >
> >
>
>
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Normally when the listserver sees a couple of bounces from an address, it
will put that address on the "hold" list for 36-48 hours, so as not to
create too much bounce traffic. My guess is that Yahoo had a major server
outage that lasted long enough for the SJSU listserver to notice. List
traffic has been high, so it wouldn't even have to be very long.
Do we have anyone on Yahoo who continued to receive list email over the last
2-3 days, or were all Yahoo accounts affected?
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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--- End Message ---
--- Begin Message ---
Cor van de Water wrote:
> Make that thousands of amps.
> Most batteries have a series resistance of a few milli-Ohm,
> mine have 4 mOhm for a 12V battery.
> When I dead-short then with capacitors, the initial burst
> will start at 12V/4mOhm = 3000 Amp.
No, hundreds. You are neglecting the capacitor's own ESR, and the
small, but still significant resistance of the cables and connections
between the caps and the battery.
If you dead short a discharged cap across the terminals of a fully
charged battery, perhaps you could get an inrush current on the order of
perhaps 1/2 the magnitude you describe (since the capacitor's ESR and
the resistance of the leads connecting it to the battery must also be
considered). However, when you string a bunch of batteries together in
an EV the resistance of all the connections and cables becomes a
significant factor in reducing the magnitude of the inrush current.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
I suffered the outage like the other Yahoos out there. But, I didn't see any
problems with another
Yahoo list I'm on, albeit a lower volume list.
--- David Roden <[EMAIL PROTECTED]> wrote:
> Normally when the listserver sees a couple of bounces from an address, it
> will put that address on the "hold" list for 36-48 hours, so as not to
> create too much bounce traffic. My guess is that Yahoo had a major server
> outage that lasted long enough for the SJSU listserver to notice. List
> traffic has been high, so it wouldn't even have to be very long.
>
> Do we have anyone on Yahoo who continued to receive list email over the last
> 2-3 days, or were all Yahoo accounts affected?
>
>
> David Roden - Akron, Ohio, USA
> EV List Assistant Administrator
>
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So far only 2 motors have been discovered that meet the criteria of an under
$450 EV motor that has a plain, non-splined shaft:
1) General Electric 5BT-1344B133, Surplus Center's part # 10-2120 - $200
9" diameter, compound wound, 149 lbs.
http://www.surpluscenter.com/item.asp?UID=2006102212332689&item=10-2120&catname=electric
2) Advanced DC AC4-4002 from ThunderStruck Motors - $425
6.7" diameter x 10" long, series wound, 72 volts, 47 lbs.
http://www.thunderstruck-ev.com/adc.htm
Motor 1 is heavy and motor 2 might be a tad small for powering a car. What
is needed is something in between. Has anyone else found any suitable
(under $450) motors? If so, could you post the URL?
Another good suggestion was fork lift salvage. Are there forklift motors
that use a plain, non-splined shaft?
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Hartsell, Fred wrote:
> 1. On page 9, figure 8 of the Curtis manual, it shows a pre-charge
> resistor in place on the Main contactor but on page 150,
> figure 10-7, of the Build your own EV book, it does not show the
> pre-charge resistor. Which is the preferred method?
Neither. You want the precharge resistor shown by the Curtis manual,
but you also want some sort of switch or relay in series with it so that
you can positively disconnect power from the controller when the vehicle
is supposed to be off.
> 2. Also both diagrams show different ways of activating the Main
> contactor; the Curtis manual uses the n.c. switch on the
> Throttle pot to activate the main contactor using the 12vdc key
> switch then the pack voltage is sent through a KSI relay to the
> controller. The book uses the key switch 12 vdc supply to activate
> the main contactor and then the pack voltage is fed to the n.c.
> switch on the throttle pot and then to the controller. Which is
> the preferred method?
This is more a matter of personal preference. If you don't include the
precharge resistor, then you want to wire it so the contactor remains
closed continuously. Wiring the main contactor so it opens each time
the throttle is released provides a greater measure of safety because in
the event of a controller failure/runawy, one of the first things you
will automaticaly do is release the throttle (thus cutting power to the
controller). The alternative switches the KSI input to the controller
to enable/disable it each time the throttle is released. This may work
reasonably well in most conditions, but if the controller fails
sufficiently catastrophically, it may not respond to the KSI input and
could remain powered up and running away even when the throttle is
released. The downside of having the contactor drop out each time the
throttle is released is that some people find the sound of the contactor
opening and closing objectionable. I have my EV wired this way, using
Kilovac contactors, and find that I have to consciously listen to try
and hear if the contactor has opened or closed, so I definitely think
the noise issue is manageable with proper contactor mounting, etc.
Cheers,
Roger.
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I asked this before, and didn't get any takers, but snce it fits into the "4th
option" thread discussing "Curtis killer" controllers I'll ask again. The
situation: I've got a Tropica which should weight about 2000 - 2400 pounds
when finished, with dual 6.7 inch ADCs - one per rear wheel, belt driven, and
designed to run at 72 volts. GThe question is this: With a 144 volt
Logisystems "hopped up Curtis" 1209, should I run the motors in series or
parallel most of the time?
Roger Stockton said:
I would stay far, far away from the hopped up Curtii until they have
been proven in *on-road* applications. The Curtis has a particularly
poor thermal design, so I would expect these hopped up controllers to
offer little if any benefit in the real world since the controller will
go into thermal cutback to protect itself when it gets hot. There also
isn't a huge amount of space in the Curtis case to add much more bus
cap, which really leaves only the option of replacing the stock caps
with better quality units (lower ESR, higher temp, etc.) A hopped up
Curtis may do just fine in a lightweight vehicle like a golf cart,
where it is unlikely to see peak amps for more than a second or two at a
time, but life in a 3000-4000lb+ on-road EV is much more demanding.
(By the way, Jim at Logisystems discourages the use of their "hopped up
Curtii" in heavier vehicles as well.)
Steve Clunn said: Keep the thing cool , alot of time my old curtis would get
so hot you couldn't put your hand on it . Don't drive in you hi a gear , steep
hills use 1st but still keep you rpm's up by driving somewhat fast . With a
120v system you can have your foot to the floor and be crusing in 2nd without
blowing up the motor , the controller is full on and is not working hard , if
your cursing in 4th the controller is working harder as the motor voltage will
be lower and the motor amparge will be much higher ( to get some power ) this
means more amps flowing through the controller and so more heat, wear and tear,
motor is also working harder.
I don't have a transmission, but I have the option of wiring the motors in
series or parallel (or switching between the two.) figure with the motors in
series, all else being equal, the controller will be dishing out half the amps
and twice the volts as it will at the same speed with the motors in parallel.
That should make the controller cooler and happier, no? So what's the
unintended consequence I'm overlooking?
---------------------------------
How low will we go? Check out Yahoo! Messengers low PC-to-Phone call rates.
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I know this is directly against the grain of your question, but why the
"no spline" rule? Spline adapters / shafts are available. Machinists
can cut splines. Failing that, splines can be machined off.
I picked up a 14T splined motor from Surplus Center. One of the other
list members (Roger Stockton, in fact. Thanks again!) here found a
splined adapter at a local (to him) auto parts store, and sent it to me.
I don't think the spline "problem" is quite so bad as you might think.
Bruce wrote:
It seems like most surplus / inexpensive motors have splined shafts but there must exist some that don't.
What DC motors are there that might be suitable for a large motorcycle or small car that cost less than say $400 and have a non splined shaft with a keyway?
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There are also plenty of splined motors on ebay right now for around
$50-200, search for EV motor or forklift motor.
-Peter
On 10/25/06, Eric Poulsen <[EMAIL PROTECTED]> wrote:
I know this is directly against the grain of your question, but why the
"no spline" rule? Spline adapters / shafts are available. Machinists
can cut splines. Failing that, splines can be machined off.
I picked up a 14T splined motor from Surplus Center. One of the other
list members (Roger Stockton, in fact. Thanks again!) here found a
splined adapter at a local (to him) auto parts store, and sent it to me.
I don't think the spline "problem" is quite so bad as you might think.
Bruce wrote:
> It seems like most surplus / inexpensive motors have splined shafts but there
must exist some that don't.
>
> What DC motors are there that might be suitable for a large motorcycle or
small car that cost less than say $400 and have a non splined shaft with a keyway?
>
>
>
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Another good suggestion was fork lift salvage. Are there forklift motors
that use a plain, non-splined shaft?
I got a Hyster forklift motor on ebay, it has a keyed shaft. More info
can be found on www.electric-lemon.com
-Peter
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Thanks Eric! The splined adapters from auto parts stores sound like a good
way to go. Can you say what they are used for in ICE cars? How would
someone find out what sizes and spline numbers are available?
Which Surplus Center motor did you get? Was it their part # 10-1422? How
did it work out?
----- Original Message -----
From: "Eric Poulsen"
> ... Spline adapters / shafts are available...
> I picked up a 14T splined motor from Surplus Center. One of the other
> list members (Roger Stockton, in fact. Thanks again!) here found a
> splined adapter at a local (to him) auto parts store, and sent it to me.
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On 25 Oct 2006 at 9:55, Dave Cover wrote:
> I didn't see any
> problems with another Yahoo list I'm on, albeit a lower volume list.
This is not a Yahoo list or group. Just to be clear, Yahoo groups and the
SJSU listserver which runs this list have nothing to do with each other.
I don't think it was Yahoo blocking the mail. It's more likely that it was
the SJSU listserver. My guess is that Yahoo bounced some mail for some or
all of its users for a short while. The SJSU listserver saw that and put at
least some of the Yahoo accounts "on hold" to prevent further bounce
traffic.
David Roden - Akron, Ohio, USA
EV List Assistant Administrator
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the webpage http://www.evdl.org/help/ .
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Roger,
Whether you use one battery or a string of many should
not matter for Isc (short circuit current) as with each
extra wire and internal battery resistance, you also
increase the voltage sufficient to give the same current
as with one battery. Ohms law simply says this:
V/R = I
so also
12V/12R = I
See - increasing the series resistance by a factor 12
because you sting 12 batteries in series will still give the
same current (luckily) because you also increase the voltage
by the same factor.
The ESR of the cap does not change though, so the effect of
the cap's ESR becomes less significant with higher pack
voltage.
So the inrush current will seriously be in the order of
a few thousand amps from a healthy high-performance pack.
I deliberately neglected the ESR, contactor resistance, fuse
resistance, breaker resistance and wire resistance, because
all that should be small compared to the pack internal resistance.
It also makes the picture harder to understand, without adding
much value - the point is that the inrush can weld, smelt and
arc and cause very nasty breakdowns real fast, due to the
uncontrolled release of several hundreds of kiloWatts for a
fraction of a second.
Regards,
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 Roger Stockton
Sent: Wednesday, October 25, 2006 9:55 AM
To: [email protected]
Subject: RE: Cursit controllers revisited (squealing); precharge
'circuit' again (please)
Cor van de Water wrote:
> Make that thousands of amps.
> Most batteries have a series resistance of a few milli-Ohm,
> mine have 4 mOhm for a 12V battery.
> When I dead-short then with capacitors, the initial burst
> will start at 12V/4mOhm = 3000 Amp.
No, hundreds. You are neglecting the capacitor's own ESR, and the
small, but still significant resistance of the cables and connections
between the caps and the battery.
If you dead short a discharged cap across the terminals of a fully
charged battery, perhaps you could get an inrush current on the order of
perhaps 1/2 the magnitude you describe (since the capacitor's ESR and
the resistance of the leads connecting it to the battery must also be
considered). However, when you string a bunch of batteries together in
an EV the resistance of all the connections and cables becomes a
significant factor in reducing the magnitude of the inrush current.
Cheers,
Roger.
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