EV Digest 5346
Topics covered in this issue include:
1) Re: Thermal measurements
by "Mike Phillips" <[EMAIL PROTECTED]>
2) Re: Thermal measurements
by "Mike Phillips" <[EMAIL PROTECTED]>
3) Re: Orb Carnage....
by DM3 <[EMAIL PROTECTED]>
4) Re: how to : determine weight from photo .. weight of images for 3 square
yards ( 9 square feet) .. and car cutout .. same ratio as AREA's ratio
by "peekay" <[EMAIL PROTECTED]>
5) RE: Prius plug in over in England
by Cor van de Water <[EMAIL PROTECTED]>
6) Re: AC vs DC; Newbie Question
by "Osmo S." <[EMAIL PROTECTED]>
7) DC-AC Upgrade Solarvan Website Updated.
by "Peter Perkins" <[EMAIL PROTECTED]>
8) Re: Thermal measurements
by James Massey <[EMAIL PROTECTED]>
9) Re: TS Internal Resistance Testing
by Victor Tikhonov <[EMAIL PROTECTED]>
10) RE: Charging Dead Flat AGMs
by "David Sharpe" <[EMAIL PROTECTED]>
11) Re: DC safety circuit
by "Evan Tuer" <[EMAIL PROTECTED]>
12) Re: how to : determine weight from photo
by jerry halstead <[EMAIL PROTECTED]>
13) Misbehaving Variac
by Mark Hastings <[EMAIL PROTECTED]>
14) Re: Misbehaving Variac
by "Evan Tuer" <[EMAIL PROTECTED]>
15) RE: Misbehaving Variac
by "David Sharpe" <[EMAIL PROTECTED]>
16) Re: Thermal measurements
by "Roland Wiench" <[EMAIL PROTECTED]>
17) Re: Porsche 911 Was: How many amps driving my EV?
by "Peter VanDerWal" <[EMAIL PROTECTED]>
18) Re: AC vs DC; Newbie Question
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
19) 300zx for sale
by "steve clunn" <[EMAIL PROTECTED]>
20) RE: Greetings)
by Bob Bath <[EMAIL PROTECTED]>
21) Re: AC vs DC; Newbie Question
by John Wayland <[EMAIL PROTECTED]>
--- Begin Message ---
James,
Good point. I should have said cannot be lengthened easily. Ordering
TC wire just is not as cheap and easy as I need it to be for testing.
In fact you reminded me that I had a tumbleweed of TC's that I don't
know what I did with. Hmmm.
Mike
--- In [EMAIL PROTECTED], James Massey <[EMAIL PROTECTED]> wrote:
>
> At 02:14 AM 10/04/06 +0000, Mike wrote:
> ><snip>I'll see if
> >mine can measure temperatures as well. Do you remember how long the
> >temp probe cable was? Mine would have to route something like 10 feet
> >or more to reach a battery. If it's a solid state device, the wires
> >could be lengthened. If it's a thermocouple, then it can't.
>
> G'day Mike, and all
>
> This is probably just a mis-use of terminology (you probably know
what you
> mean), but a thermocouple can be lengthened, no problem, as it is
made from
> wire. You just need to use thermocouple wire to do it with. Other
types of
> electronic-signal sensor usually can be lengthened with ordinary copper
> wire (I can't actually think of any that can't).
>
> Since you're talking about an electronic meter the sensor will not be a
> capillary tube - which are the type you can't lengthen as they are a
sealed
> system.
>
> Regards
>
> James
>
--- End Message ---
--- Begin Message ---
Excellent! So that implies it's a solid state part of sorts. Have you
compared it to a reliable source?
Thanks,
Mike
--- In [EMAIL PROTECTED], "Roland Wiench" <[EMAIL PROTECTED]> wrote:
>
> Mike,
>
> The Link-10 wire length in my EV is a 25 foot of double shield No.
16 gage 5
> pair (10 wires) stranded wire that each wire has a aluminum tape
shield and
> than a over all expanded aluminum shield under a plastic cable jacket.
> This wire is design-for the Link-10 where each pair that twisted one
turn
> per foot through out its length.
>
> My total length from the E-meter to a setscrew terminal block that
is in the
> equipment compartment next to the battery charger is 25 feet. The
sensor
> unit which I pick up from EV Parts has a 6 foot length of two wires
that is
> also jacket. This makes a total length of 30 feet for me.
>
> Roland
>
>
>
>
> ----- Original Message -----
> From: "Mike Phillips" <[EMAIL PROTECTED]>
> To: "Roland Wiench" <[EMAIL PROTECTED]>
> Sent: Sunday, April 09, 2006 8:14 PM
> Subject: Re: Thermal measurements
>
>
> > Roland,
> >
> > Thanks so much for your information. I had forgotten that the Emeter
> > has that capability. I'm not sure if it's optional or not. I'll see if
> > mine can measure temperatures as well. Do you remember how long the
> > temp probe cable was? Mine would have to route something like 10 feet
> > or more to reach a battery. If it's a solid state device, the wires
> > could be lengthened. If it's a thermocouple, then it can't.
> >
> > But in the mean time the Acurite stuff would work just fine for
> > nailing down the thermal behavior of the pack. I wish the dolphin had
> > a thermal measurement as well for the pack, then I could log it while
> > driving/charging.
> >
> > I wish I had room for insulation. I will also have to look closely at
> > ventilation as well for excess heat. I've got some serious
research to do.
> >
> > Thanks again!
> >
> > Mike
> >
> >
> >
> >
> > --- In [EMAIL PROTECTED], "Roland Wiench" <ev@> wrote:
> > >
> > > Hello Mike,
> > >
> > > To read my battery pack temperature on the go, I'm using a
temperature
> > > sensor that is design for the Link-10 E-meter.
> > >
> > > It is a two wire temperature sensor that connects to the No. 6 and
> > No. 8
> > > terminal strip on the back of the Link-10. The part No. for this
> > sensor is
> > > 1N2535.
> > >
> > > The sensor is bolted on any one of the battery post. The
> > temperature prod
> > > is imbedded in side a wire lug and isolated from any metal of the
> > wire lug.
> > > The wire lug is than either bolted to a extended battery post clamp
> > or a
> > > battery stud.
> > >
> > > This morning, in Great Falls, Montana, it was 40 degrees F.
Inside my
> > > garage the on wall temperature is 65 degrees F. I turn off the
heating
> > > system for the winter, but I have a super high R-factor insulation
> > that is
> > > 80 R's for the wall and 140 R's ceiling and a garage door of 20 R's,
> > so it
> > > maintains this temperature for a long time and even into the summer.
> > >
> > > The battery pack is also in a super insulated battery box, so even
> > after
> > > driving the EV, it will hold the battery temperature range from 62
> > to 65
> > > degrees.
> > >
> > > This morning when, the battery temperature was at 17 degrees C. or
> > 62.6 F.
> > > Driving for one mile at 50 battery amp, the temperature rose to 18
> > degrees
> > > C. or 64.4 F. After letting the EV set one hour in a outside
ambient
> > > temperature of 40 F. the Link 10 still had a read out of 18 C. It
> > may be
> > > between 17.5 and 18 C.
> > >
> > > This is with a 260 AH battery pack that weighs more than a ton. A
> > smaller
> > > pack at a lower AH will increase in temperature faster and lose the
> > > temperature quicker.
> > >
> > > Driving home for another mile at 50 battery amp the battery
temperature
> > > still read 18 C. Letting the EV set for 20 hours, the temperature
> > will be
> > > down in the 17 C. range or about 62+ F.
> > >
> > > If you battery pack is un-insulated, then the battery post will be
> > the same
> > > temperature as the ambient air very quickly.
> > >
> > > To read the temperature on a Link-10, press F3 for a read out.
> > >
> > > Before I had a Link-10, I used a small battery operate temperature
> > gage made
> > > by ACURITE which you can get from WalMart. It has a 10 foot
cable and
> > > sensor, normally for reading outside temperature from inside you
> > house. I
> > > used many of these sensors, when I was building my high R-Factor
> > house, for
> > > testing the floor to ceiling and inside wall to outside ambient
> > temperature.
> > >
> > > I normally keep my battery pack in about the 65 degree range all
winter
> > > long. In summer, the battery back temperature is between 70 and 75
> > F. I do
> > > not drive that far, so I do not have to squeeze every AH out it.
I get
> > > about 2000 cycles out of my batteries, because I at 80% capacity
> > about 95%
> > > of the time. For me this is about 100 cycles per year or would be
> > 20 years.
> > > I normally get 10 to 12 years out of a battery pack.
> > >
> > > Roland
> > >
> > >
> > > ----- Original Message -----
> > > From: "Mike Phillips" <mikep_95133@>
> > > To: <ev@>
> > > Sent: Sunday, April 09, 2006 11:30 AM
> > > Subject: Thermal measurements
> > >
> > >
> > > > Has anyone measured their battery temperatures? Just curious
what you
> > > > used and what numbers you got in various conditions.
> > > >
> > > > I'm secretly hoping for proven schematic with part numbers
cause I'm
> > > > buried right now.
> > > >
> > > > But even meat thermometers qualify to answer the question.
> > > >
> > > > Mike
> > > >
> > > >
> > > >
> > > > Here's to the crazy ones.
> > > > The misfits.
> > > > The rebels.
> > > > The troublemakers.
> > > > The round pegs in the square holes.
> > > > The ones who see things differently
> > > > The ones that change the world!!
> > > >
> > > > www.RotorDesign.com
> > > >
> > > >
> > >
> >
> >
> >
> >
> >
> >
>
--- End Message ---
--- Begin Message ---
Seppo,
I guess this is as good a time as any to reveal an old (formerly secret)
strategy, I have been using diodes in this manner since 1993. Back when I
started racing in the Solar Electric 500 in Phoenix one of my first
concerns was to finish every race I started. Most of the races from 1993
thru 1999 were for 45 miles! I think only one race was 25 miles. These
races were quite a challenge and the strategy was to run out of energy
just as you crossed the finish line at mile 45.
As we all know one dead battery can bring down the string in just a few
minutes, so I wanted to switch out or bypass each battery as it died -
thereby prolonging the use of energy from the "good" batteries. I soon
found out from a good power supply designer (Jerry T.) I could do this
with a bypass diode.
At the end of some of the races my pack would die about one or two laps
before the lead car passed the finish line. The diodes would bypass the
dead batteries and I was able to limp over the finish line with a pack
voltage of around 40 volts, as a result no DNFs! The first year I was the
only one using diodes and by the end of the 90s there were about 4 teams,
we all kept it secret and never discussed it. It was known to spy on each
other for these tricks and larger teams had individuals that did only
that. Trying to keep your advantage is one of the things that makes
racing fun.
Us independants were racing against cars built by power companies like APS
and SRP, these cars cost from several hundred thousand to 1 million
dollars, their cars in the open wheel division (where I raced the
voltbuggy) swapped battery packs every 2 or 3 laps.
Every year I would have people come up after the race asking what kind of
batteries I used because the car never completely died. The surprise is
that as the (Trojan T125) batteries die, the first batteries bounce back
and it seems to limp for a long time. Of course, I know some of you are
gasping or imaginining how the batteries are dead meat at this point but I
charge the batteries immidiately after one of these discarges. I used my
first pack for 6 years befor selling them (load tested GOOD)in useable
condition.
I use the Magnificent INTERNATIONAL RECTIFIER DIODE PN 409CNQ150. These
are 150 volt, 400 amp schottky diodes. Only one out of 50 has failed in
13 years! The Voltbuggy was the first vehicle I implemented them, you can
see them in Episode 12 of "Cool Fuel Roadtrip" as the camera quickly pans
the battery pack.
I use no heatsink except the battery post and strapped terminals 1 and 2
together with a homemade cable end. I think this beats the clap trap of
relays monitors or switches I originally imagined hooking up before using
these diodes.
I also implemented some TO220 schottkys on my sons RC car. When he raced
and his pack died, he always had enough energy to limp at least 1 or 2
more laps while the other cars stopped dead in thier tracks.
I am sure there are some disadvantages but there is nothing worse than a
stone dead string.
Going for one more lap,
Jimmy
PS: I think it also helps avoid battery post meltdown but can't prove it.
http://www.dm3electrics.com/
> Seppo wrote:
> > What would happen if you simply connected a (very sturdy) diode in
> > parallel with each battery? If the battery cannot keep in pace with
> > the others and starts to go negative, the diode would start
> > conducting the load current past the battery when the battery voltage
> > is down to -0.7 V.
--- End Message ---
--- Begin Message ---
hello neon john
absolutely right on every count ..
we are not teaching that way anymore .. bad .. but fact
about 'scanning' your thousands of book .. don't
it is a very painful and slow process
we now use high re digital cameras to take images
once setup .. you can do several books a day
if you get two digital cameras .. well the time becomes half
three doesn't make a big difference .. time becomes only one third
get your girlfriend, wife, daughter to help (sons never help dads )
..peekay
(make dvd's .. maybe you can even sell them to friends .. on
cost sharing plus something to cover the effort)
----- Original Message -----
From: "Neon John" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, April 10, 2006 10:33 AM
Subject: Re: how to : determine weight from photo .. weight of images for 3
square yards ( 9 square feet) .. and car cutout .. same ratio as AREA's
ratio
> On Mon, 10 Apr 2006 10:02:32 +0530, "peekay"
> <[EMAIL PROTECTED]> wrote:
>
> >this is a very novel idea .. the only issue is getting a jeweller's scale
>
> This is a very old idea, going back at least a couple centuries.
> Especially before calculators, scientists had to come up with all
> sorts of nifty tricks in order to get work done instead of grinding
> out endless calculations.
> >
> >may i humble suggest :
> >
> >cut a plywood sheet to match the paper size, paste the printout..
> >cut the car image out .. weighing is easier .. kitchen scale can be used.
>
> Yes, that will work well but only if the plywood is very uniform - no
> internal voids or glue pockets. Particle board or OSB would probably
> be better than plywood. Adding weight to the paper is why I suggested
> printing on the heaviest stuff that would feed through the printer.
>
> I mentioned the jewelers because most jewelers have some sort of
> sensitive scales. Just haul your two pieces of paper to the store and
> ask to weigh them. The novelty of the request almost always meets
> with success. That was my standard method before I acquired a
> suitable balance of my own.
>
> As an aside, I've had a life-long hobby/avocation (since about the age
> of 6, anyway) of collecting old technical, scientific and mathematical
> books. My library now numbers in the thousands of volumes and is one
> of the most valuable resources I have, right behind the net.
>
> It is quite unfortunate in this day of computers and calculators and
> new math that the old methods of computation, measurement and other
> shortcuts aren't taught anymore. These methods are frequently as fast
> or faster than computational methods with adequate accuracy for the
> job at hand. These methods also can usually be used without a
> Pentagon budget to buy test equipment and computers.
>
> I'm reminded of Enrico Fermi's estimation of the yield of the first
> atomic bomb to better than 10% by merely dropping scraps of paper into
> the blast wave as it went by, measuring the distance they were
> deflected and using some approximations that he could do in his head
> with the aid of his ever-present slide-rule, came up with about the
> same number as the instrument guys did, only they took weeks to crunch
> the numbers.
>
> I only wish I had the time and money to scan these old books and put
> them on the net. Meanwhile, the used book stores are the engineer's
> best friends.
>
> Probably the most useful lesson I learned in school was taught to me
> by my 9th grade chemistry teacher. He taught that most problems can
> be reduced to simple ratios. Many of the more complex parts of
> problems reduce to either constants, 0 or 1 and can be ignored. He
> was absolutely correct. I extend the notion by adding an occasional
> exponent, root or log to the simple ratio.
>
> John
> ---
> John De Armond
> See my website for my current email address
> http://www.johngsbbq.com
> Cleveland, Occupied TN
> A foolish consistency is the hobgoblin of little minds.-Ralph Waldo
Emerson
>
>
>
> --
> No virus found in this incoming message.
> Checked by AVG Free Edition.
> Version: 7.1.385 / Virus Database: 268.4.0/306 - Release Date: 09/04/2006
>
>
___________________________________________________________
NEW Yahoo! Cars - sell your car and browse thousands of new and used cars
online! http://uk.cars.yahoo.com/
--- End Message ---
--- Begin Message ---
IIRC they replaced the entire Battery ECU with the battery and
it's BMS and they also had an issue with CAN bus noise, which
was solved by isolation in the powering to avoid ground loops
via the supply:
>In the configuration of my last update of 11/24, my PRIUS+ has been
>running CAN-bus-error free. I bought a small 12V-to-115VAC inverter
>which I'm powering from the 12V supply to the VT board. The VT board is
>now running from the output of an AC adapter plugged into the inverter,
>creating an isolated power supply. This works O.K, though it
>occasionally powers up too slowly and the vehicle's READY light doesn't
>come on. I just try again.
>
>Eventually we will have to address the CAN bus noise again, but in the
>meantime the problem has been successfully swept under the rug.
(From the 11/24 post:)
>Now the even better news -- and this is unexpectedly great! If I jack
>the SOC the CDU (our replacement for Toyota's Battery ECU) reports to
>the CAN bus up to e.g. 90%, the THS tries to lower the perceived
>excessive battery charge by running partially on electrical power all
>the time. This provides for a continuous discharge rate of 30-50A and
>gave me a mostly-freeway mileage last night of 83 mpg!
So, this tells me that they had to reverse-engineer the Battery BMS
functionality and implement that (again) with modifications for the
larger pack PLUS tricks to dynamically increase and reduce SOC reports,
so the vehicle would still regen during braking (lower SOC reporting
during braking) and use electric assist on the freeway (higher SOC).
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 Lee Hart
Sent: Sunday, April 09, 2006 8:53 PM
To: ev@listproc.sjsu.edu
Subject: Re: Prius plug in over in England
Mike Phillips wrote:
> The guys at CalCars.org did just that. 20ah AGM's. It worked pretty
> well. Now They are moving to Lithium I believe.
That's an example of what I meant; everyone I know of is going high-cost
lithiums.
> At the Maker Faire this month they are going to convert a Prius to a
> Plug in Prius right in front of everyone, then the owner drives it
> back to Washington/Oregon.
I wish I could see this. In particular, I'd like to know how they are
defeating the Prius's built-in battery state of charge controls and
alarms.
--
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 ---
DC vs AC ... what about sepex, PM, BLDC and whatnot. Do they all belong
in the category of DC? Or does DC stand for a brushed series wound
motor only. If so, why aren´t the others hardly ever discussed in this
group?
Thanks,
Osmo
--- End Message ---
--- Begin Message ---
I have now updated my website with details of my completed DC to AC upgrade.
It contains lots of pictures and various downloadable files.
A few minor glitches to sort.
I hope you approve.
Regards
Peter Perkins UK
www.solarvan.co.uk
--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.1.385 / Virus Database: 268.4.0/305 - Release Date: 08/04/2006
--- End Message ---
--- Begin Message ---
At 05:34 AM 10/04/06 +0000, you wrote:
Excellent! So that implies it's a solid state part of sorts. Have you
compared it to a reliable source?
Thanks,
Mike
> > > terminal strip on the back of the Link-10. The part No. for this
> > sensor is 1N2535.
Hi Mike, Roland and all
The implication is that they have used a normal part number, that part is a
silicon diode, something like 50V 1A (IIRC, without getting out the
databook). If that is so, pretty much any silicon diode of this sort of
size should substitute, i.e. a 20 cent part (if that), the rest is the
housing. No problems with cold junction compensation or wire resistance,
but a very small signal that is easy to interfere with - hence the twisted,
shielded instrument grade (expensive) cable. Roland, does this sound like
what you have?
Regards
James
--- End Message ---
--- Begin Message ---
Bill, you don't use OCV for this.
R_int = delta_V/delta_I
I suppose you're interested to know discharge R_int (see below).
Load the cell with the current close to one it will mostly be
used at, say 40A and at the temp you'll be using it, and note the
voltage V1. It will keep dropping, but that's OK.
Increase the load to 50A (by connecting extra
something in parallel to the main load) and immediately check the
voltage again - V2. Remove extra load and check it third time - V3.
Try to do all 3 measurements quickly, say within 2 sec each.
Average voltage 1 and 3, this will be your voltage for 40A load,
call it V12. R_int is (V12-V2)/10A. In general case it is divided
by the currents delta, in this case 50A-40A=10A.
Hypothetical example:
40A load = 3.35V
50A load = 3.14V
back to 40A load = 3.33V now (because the cell has depleted a bit).
Average voltage for 40A is 3.34V.
R_int = (3.34V-3.14V)/10A = 0.2V/10A=0.02 Ohm.
1. Result is very dependent on SOC. As you discharge,
R_int for discharge increase as well as rate of it's increase.
2. Charge R_int is different from discharge R_int at the
same SOC. Charge R_int would be if you charge cell with 40A,
measure voltage, increase charging current to 50A, measure
voltage, drop charging current back to 40A and measure again.
3. R_int is very temp dependent, the lower temp the more R_int,
and below 0'C it is sharply increased.
4. R_int is not linear - at light loads it will be different
vs. heavy loads. How different - interestingly depends on duration
of testing - for light loads R_int will appear lower, but for heavy
ones it is higher in the beginning but only if you won't allow
measurement to raise the cell temp so that this heating effect,
lowering R_int outweigh increased R_int because the load itself is
heavy. Outcome of such test may get confusing, so just measure it
quickly at one point typical for your driving - that's what is
relevant.
Hope this helps.
Victor
Bill Dennis wrote:
How do I test for the internal resistance of a ThunderSky cell? My first
attempt was to hook three cells in series, then connect them to the motor.
The OCV was 12V, and about 35A was being drawn when the circuit was
connected. I thought I would compare the voltage at 35A to the open circuit
voltage. But the voltage never stayed the same. It just kept dropping all
the time (about 1/100 volt every 10 seconds).
Do I need to test with a lower current, or is there some other method for
testing the resistance?
Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
I have tried this. The cells are not defective. They have been neglected for
about 5 years. There are 12 300 Ahr cells in total. I suspect they are
massively sulphated. Procedures for wet cells don't seem to work on AGMs.
Any other ideas?
David
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: Monday, 10 April 2006 3:15 PM
To: ev@listproc.sjsu.edu
Subject: Re: Charging Dead Flat AGMs
David Sharpe wrote:
>
> Has anyone been able to charge flat AGMs. I have tried charging using
about
> 50V DC in series with a 100W light bulb. 2V appears on the terminals but
the
> trial cell will not charge. Any suggestions?
> David Sharpe
If they were allowed to run very dead, their internal resistance can be
so high that no current will flow. No current means they don't charge;
thus they STAY dead.
If there is nothing else wrong with the AGM (it's just deeply
discharged, not defective), then leave a moderately high voltage on it
(about double its rated voltage, i.e. 24v for a 12v battery), with a
resistor or light bulb or something to limit the current to about 1-2%
of its rated amphour capacity.
--- End Message ---
--- Begin Message ---
On 4/10/06, Michaela Merz <[EMAIL PROTECTED]> wrote:
>
> Since I read about how bad DC controllers might fail (well, I kind of knew
> that before but .. ) I was driving down the road with my foot on the
> clutch. And I was thinking: It can't be too complicated to have some sort
> of fail safe that would 'kick in' if a controller breaks down.
>
> A micro switch on the potbox would have to be combined with a voltage
> sensing circuit at the motor. If the foot is off the gas pedal and there's
> still voltage supplied to the motor: Throw the contactor.
I've tried this, and it works, but you have to be careful to avoid
"false alarms". The motor voltage does not vanish immediately, so I
disovered that if you let your foot off the pedal very quickly while
moving fast, it would drop out the contactor. But, if you set the
voltage triggering too high (or add a delay) it might not be sensitive
or fast enough to prevent some damage if the controller really did
fail on, and it's hard to test. So, a circuit that senses current
might be a better idea.
> If a circuit
> would be able to distinguish between a PCM signal and a 'flat' DC (which
> would be the case if the controller fails?) it would be able to kill main
> power without any need to sense the gas- or brake pedals.
Remember that the motor will get "flat" DC once the duty cycle of the
controller reaches 100%. On my old car this was about 40mph so quite
regularly :)
--- End Message ---
--- Begin Message ---
On Apr 10, 2006, at 1:03 AM, Neon John wrote:
I only wish I had the time and money to scan these old books and put
them on the net. Meanwhile, the used book stores are the engineer's
best friends.
Hi John,
Maybe you can work something out with Google? They are scanning
libraries:
http://print.google.com/googleprint/library.html
-Jerry
http://www.evconvert.com/
--- End Message ---
--- Begin Message ---
I have been using what is listed to be a 10 amp isolated variac for about 6
months either on my truck or my electric tractor. Recently It is very finicky
about where it will turn on and not turn on when I adjust the dial. The
indicator on the front always stays lit and the voltage displays on the analog
gauge but it doesn't put out any amps and when I use my DMM their is no voltage
on the outputs. Yesterday it actually would only work if if I pushed down on
the dial. I only used it for a few minutes like this and then unplugged it.
I don't use it for more than 5-6 amps A/C with a 35amp full bridge. Is there
anything I can do to revive it or is it a loss? Can I use it with say a rock on
it until that part of the coil burns out too?
Thanks,
Mark Hastings
--- End Message ---
--- Begin Message ---
Check the brush, and its connections. If it's working at all then the
winding must be intact, but the track where the brush makes contact
may be burnt or dirty. Simply cleaning it up and replacing the brush
if necessary should fix it.
On 4/10/06, Mark Hastings <[EMAIL PROTECTED]> wrote:
> I have been using what is listed to be a 10 amp isolated variac for about 6
> months either on my truck or my electric tractor. Recently It is very finicky
> about where it will turn on and not turn on when I adjust the dial. The
> indicator on the front always stays lit and the voltage displays on the
> analog gauge but it doesn't put out any amps and when I use my DMM their is
> no voltage on the outputs. Yesterday it actually would only work if if I
> pushed down on the dial. I only used it for a few minutes like this and then
> unplugged it.
> I don't use it for more than 5-6 amps A/C with a 35amp full bridge. Is
> there anything I can do to revive it or is it a loss? Can I use it with say a
> rock on it until that part of the coil burns out too?
> Thanks,
> Mark Hastings
>
>
--- End Message ---
--- Begin Message ---
Sounds like you have burnt out or worn out the brush
David
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mark Hastings
Sent: Monday, 10 April 2006 10:33 PM
To: ev@listproc.sjsu.edu
Subject: Misbehaving Variac
I have been using what is listed to be a 10 amp isolated variac for about 6
months either on my truck or my electric tractor. Recently It is very
finicky about where it will turn on and not turn on when I adjust the dial.
The indicator on the front always stays lit and the voltage displays on the
analog gauge but it doesn't put out any amps and when I use my DMM their is
no voltage on the outputs. Yesterday it actually would only work if if I
pushed down on the dial. I only used it for a few minutes like this and then
unplugged it.
I don't use it for more than 5-6 amps A/C with a 35amp full bridge. Is
there anything I can do to revive it or is it a loss? Can I use it with say
a rock on it until that part of the coil burns out too?
Thanks,
Mark Hastings
--- End Message ---
--- Begin Message ---
----- Original Message -----
From: "James Massey" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, April 10, 2006 2:41 AM
Subject: Re: Thermal measurements
> At 05:34 AM 10/04/06 +0000, you wrote:
> >Excellent! So that implies it's a solid state part of sorts. Have you
> >compared it to a reliable source?
> >
> >Thanks,
> >
> >Mike
> >
> > > > > terminal strip on the back of the Link-10. The part No. for this
> > > > sensor is 1N2535.
>
> Hi Mike, Roland and all
>
> The implication is that they have used a normal part number, that part is
> a
> silicon diode, something like 50V 1A (IIRC, without getting out the
> databook). If that is so, pretty much any silicon diode of this sort of
> size should substitute, i.e. a 20 cent part (if that), the rest is the
> housing. No problems with cold junction compensation or wire resistance,
> but a very small signal that is easy to interfere with - hence the
> twisted,
> shielded instrument grade (expensive) cable. Roland, does this sound like
> what you have?
Yes, I pick it up from EV Parts when I was there. Roland
>
> Regards
>
> James
>
>
--- End Message ---
--- Begin Message ---
> I'm leaning toward the Toyota Pickup with Phil Knox's aerodynamic mods
> that reduce the Cd from 0.44 to 0.25. Which would bring the CdA to
> 7.0. Smoother than the Saab and less weight.
>
That actually sounds like the best idea. The mid-80s Toyota pickups were
very small (frontal area, etc.), relatviely light, and could hual a LOT.
I do wonder about how they came up with the 0.25 Cd figure. Did they
actually measure it, or just guess?
It's a pretty impressive number, but then that's an impressive looking truck.
--
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 ---
But an AC motor with a shorted controller doesn't lock up. It just
gives max torque with saturated rotor. The tires may, or may not,
slip. The tires will certainly continue to turn. If they stop
turning, the motor torque goes to zero.
Bill Dube'
At 10:08 PM 4/8/2006, you wrote:
On Sat, 08 Apr 2006 14:53:26 -0600, "[EMAIL PROTECTED]"
<[EMAIL PROTECTED]> wrote:
>Here are the possible situations:
<snippity>
> In noneof these situations would you be better off with the
>DC motor directly connected to the battery pack compared with an AC
>motor with shorted windings. In many of these situations, an AC motor
>with shorted windings would not be dangerous, but a DC motor
>connected directly to the pack would be likely fatal.
With whatever respect is due, Bill, no.
Have you ever been in a car or on a motorcycle and had an instant
lockup? Not a seizure where you have a fraction of a second warning
but a stick-in-the-spokes type lockup? I have. 3 times.
First time: 250 Ossa Pioneer enduro bike, returning from the finish
line of an enduro on a paved, flat and level forest service road.
Raining. Water spray from the front wheel is chilling the front of
the cylinder, distorting it. I'm running a little low on gas and the
engine is pinging a little (it's spanish, that's what it does!) I
approach a large sweeping turn at about 45 mph, lift throttle slightly
and start to lean in. The piston seizes and because of that fine
spanish metallurgy (NOT), the rod yanks the pin out of the piston and
and as the rod heads out through the bottom of the crankcase, it
promptly locks the crankshaft.
I've suffered more piston seizures than I care to count and had
trained myself to fan the clutch at the first sign of tightness. Not
a wisp of a chance this time. One instant I'm starting to turn and
the next I'm sliding on my *ss down the highway, leaving a nice streak
of butt-cheek on the pavement. I still have a couple of hunks of
keyring embedded in my butt from that one. Yeah, I was in blue jeans
and no, nobody wore leathers on enduros back then.
Incident two. I'm tuning a Suzuki 125cc roadracer that we were
preparing for Daytona. I hadn't noticed the nut caught behind the
brake shoe on the rear brake when I put the rear wheel back on. I
lean into a 60 mph turn and apply just a little brake to set it up.
That nut comes loose and instantly locks the wheel. Again, I'm on my
*ss before I could even process what was happening. Fortunately I was
in leathers and boots so no harm done, at least to me.
Incident 3. Porsche Club of Atlanta track days, Road Atlanta. I'm in
a customer's 280Z track car doing some hot laps to check out some
tuning changes, probably running 70% of full race speed. I braked for
the turn under the bridge, then eased back on the throttle. I'm not
sure what happened, whether a tooth in the third member broke or
something was left inside or something else came loose. In any event,
with zero warning the rear instantly locked up.
It was just like on the bike but without the road rash. I was
spinning before the engine quit turning. All the way down the hill in
the dirt. Fortunately, nothing broken except my pride. If that had
been on the street with a wall or tree or telephone pole on the edge
of the road then I might not be typing right now.
I'll take a stuck throttle ANY DAY UNDER ANY ROAD CONDITIONS over an
instant lock-up such as a shorted AC controller phase would cause. I
can either stall or come close to stalling a motor with a stuck
throttle/shorted controller using the brakes, at least enough to hit
the kill switch or if I crash, not hit very hard.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
--- End Message ---
--- Begin Message ---
I have a 300 zx , conversion with 25 golfcart batteries , 1k zilla , 9 " net
gain , power steering , power brakes . . The owner has moved and I have it
up for sale at www.grassrootsev.com . I'm looking for somebody to be
partners on this car while I keep it up for sale ( or buy it ) . It has
almost new batteries , and sitting not the best for them . There are a few
ods and ends that need attition , wiper motor , door handle , power window .
I'm ready to make almost any deal , but will pick the best offer that comes
along . I'd like to see this car in the Fort Pierce rally , diving in the
distance comatition . steve clunn 772-971-0533
--- End Message ---
--- Begin Message ---
Sorry to hear life hasn't been the proverbial bowl of
cherries. Welcome back!
The fact that you've been willing to stick your
neck out and test exotic battieries, and have the
software and engineering support to make them work
makes you my (our) new best friend!
In your absence, Bill MacFarland retired from
Saddleback's Mech Tech dept. so there is no more Alt.
Propulsion program there. I haven't heard from Leo
Galcher in ages. And if I ever got ahold of that
guy-- John ----, I'd ask for a couple of his cool
E-meter power supply boards. He had a great product
that I'm sure we'd pay a little bit extra for to get
the fuse and LED support around the chip for.
My CivicWithACord is now 4,500 mi. Would be more
if my commute was a bit longer. Medford is a 70+ mi.
round trip; a bit far for 18 floodies, I'm afraid.
Anyway, the next time you do the I-5 corridor, feel
free to drop by for a coffee/soda/beer and a look!
Good luck on the next phase of Quantum!
> > At 03:21 PM 4/9/2006, you wrote:
> > >As many of you know, I kind of slipped out of the
> EV world (and
> > >arguably out of any world) for the past two
> years. However, I'm
> > >back, and I'm determined to install a NiCad or
> NiMH battery pack in
> > >quantum mechanic.
> > >
> > >(alter ego sez: He just doesn't give up, does he
> folks)
> > >
> > >I'm currently in negotiations with SAFT, but if
> anyone has any other
> > >suggestions for NiMH/NiCad, please let me know.
> > >
> > >My NiZn b
> > >
> > >Minimum requirements:
> > >
> > >55Ah
> > >capable of sustained 100A/2C, bursting to 250A/5C
> > >
> > >I'm willing to install a water cooling system if
> that turns out to
> > >be advisable.
> > >
> > >I will attempt to read this list regularly again.
> Sorry that I went
> > >away.. bad things happened in my personal life.
> > >
> > >Sheer
> > >
> >
> >
> >
> > --
> > No virus found in this incoming message.
> > Checked by AVG Free Edition.
> > Version: 7.1.385 / Virus Database: 268.4.0/305 -
> Release Date: 08/04/2006
> >
> >
>
>
>
>
___________________________________________________________
>
> To help you stay safe and secure online, we've
> developed the all new Yahoo! Security Centre.
> http://uk.security.yahoo.com
>
>
>
'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?
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Hello Osmo and All,
Osmo S. wrote:
DC vs AC ... what about sepex, PM, BLDC and whatnot. Do they all
belong in the category of DC? Or does DC stand for a brushed series
wound motor only. If so, why aren´t the others hardly ever discussed
in this group?
When talking EV sized brushed wound field type motors, it is generally
assumed that they are series-wound types. They don't have to be, they
could also be shunt wound, sepex, or PM types.
BLDC (brushless DC) motors are as complicated to control as AC motors
are, in that they require an inverter or they cannot run. A BLDC is
really an AC motor who's inverter is generally built into the motor
case. It's an AC motor that has no brushes but you feed it raw DC
power...hence brushless DC. Once the power gets into the motor it's
routed through an inverter that converts it to three phase AC. Most are
synchronous types where the rotor is a permanent magnet, so they have
different characteristics compared to induction type AC motors. Today's
BLDC motors have changed and many now have three feed wires that get
power from an external inverter. To me, I call this an AC motor, but the
companies that build these still insist on calling them BLDC....go
figure! In a nutshell, a BLDC motor is essentially an AC motor, thus an
EV BLDC system with EV levels of power have the same high cost as the
induction type AC systems. Unique Mobility makes EV sized BLDC systems,
but I think they're priced in the $20k range. I rode in a Humvee powered
by four Unique Mobility 100 hp BLDC motors, it was incredible! At $20k,
you can see why we don't talk much about them or use them often.
On a much, much smaller scale, I do own an EV that's powered by a BLDC
motor, it's my very early model Curie board scooter. When other scooters
of the period (pre-2000) were still stuck in 12V land, had a PM motor
that ran at 57% efficiency with a binary controller (an on-off switch)
and used a friction drive or belt drive, this one ran at 24V, had a
chain drive, and employed Curie's own design BLDC motor at about 95%
efficiency with variable throttle control due to the built-in
inverter-controller on the backside of the motor. Scooters back then
were rated at 15 miles range per charge, but in reality got about 6-7
miles before needing a recharge. My Curie was rated at 12 miles per
charge and easily did it. It was also way faster on top end, and off
throttle it coasts forever so you only need to blip the throttle once in
a while to cruise along. After a few mile son a regular PM 12V scooter,
the motor got very hot to the touch, but the Curie BLDC feels barely
warm. Today, I have five board type scooters, but my favorite is still
my original Curie with its BLDC motor. I just bought a new 36V Curie
that has a real disc brake, and full suspension and all, but the
disappointing factor is its PM brushed motor. It even has the warning
'Caution, motor gets hot!' I assumed when I ordered this scooter, it
would be an upgraded version of my trusty Curie ...not!
As to sepex and PM, yes, these are considered to be good 'ol DC motors.
There aren't many large PM motors readily available in road going EV
sizes, and a PM of this size would not have the ultimate low end torque
of a series wound type, thus, they are not popular. Sepex are also, not
readily available and they require more complicated controllers. Randy
Holmquist of Canadian EV has rewound Kostovs that are turned into sepex
types. Jim Husted could also turn any motor into a sepex type. Sepex
have really taken over in the forklift industry and with gear ratios
changed to improve low end torque making them on par with series wound
types, they work very well, with the added plus of very controllable regen.
Hope this helps...
See Ya....John Wayland
--- End Message ---
