EV Digest 6523
Topics covered in this issue include:
1) Re: [EV] RE: [EV] RE: Kilovac EV-200 as safety disconnect?
by Eduardo Kaftanski <[EMAIL PROTECTED]>
2) Re: Motor blower
by Lee Hart <[EMAIL PROTECTED]>
3) Re: Need advice on Lee Hart's batt-bridge circuit
by Lee Hart <[EMAIL PROTECTED]>
4) Re: Safety Disconnect
by Lee Hart <[EMAIL PROTECTED]>
5) Re: 300V EV Questions
by Lee Hart <[EMAIL PROTECTED]>
6) Re: FWD friction
by Lee Hart <[EMAIL PROTECTED]>
7) Re: Curtis 1231C squealing solution
by Lee Hart <[EMAIL PROTECTED]>
8) Re: Manual Transmission Rebuild
by "Roland Wiench" <[EMAIL PROTECTED]>
9) Re: Regenerative suspension
by "Michael" <[EMAIL PROTECTED]>
10) Re: Curtis 1231C squealing solution
by James Massey <[EMAIL PROTECTED]>
11) Choosing diodes for a rectactor circuit.
by "damon henry" <[EMAIL PROTECTED]>
12) Heatsinking a Curtis
by "Phil Marino" <[EMAIL PROTECTED]>
13) RE: subaru
by "Michael" <[EMAIL PROTECTED]>
14) Re: subaru
by john fisher <[EMAIL PROTECTED]>
15) Re: Precharge Resistor Primer
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Economics of balancing amps
by Lee Hart <[EMAIL PROTECTED]>
17) Re: Manual Transmission Rebuild
by "Death to All Spammers" <[EMAIL PROTECTED]>
18) Re: Electric Ford Ranger on E-bay
by "Death to All Spammers" <[EMAIL PROTECTED]>
19) Re: Need advice on Lee Hart's batt-bridge circuit
by Lee Hart <[EMAIL PROTECTED]>
20) Re: Electric Ford Ranger on E-bay
by "Matt Kenigson" <[EMAIL PROTECTED]>
21) Re: Manual Transmission Rebuild
by Mark Farver <[EMAIL PROTECTED]>
22) Re: Need advice on Lee Hart's batt-bridge circuit
by Nick <[EMAIL PROTECTED]>
23) RE: FWD friction
by "Claudio Natoli" <[EMAIL PROTECTED]>
24) RE: FWD friction
by "Claudio Natoli" <[EMAIL PROTECTED]>
25) RE: FWD friction
by "Claudio Natoli" <[EMAIL PROTECTED]>
26) Re: Curtis 1231C squealing solution
by Lee Hart <[EMAIL PROTECTED]>
27) Re: Regenerative suspension
by Danny Miller <[EMAIL PROTECTED]>
28) Re: Curtis 1231C squealing solution
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
29) Re: Curtis 1231C squealing solution
by "Ev Performance (Robert Chew)" <[EMAIL PROTECTED]>
30) Reading Material
by KARSTEN GOPINATH <[EMAIL PROTECTED]>
31) Re: Kilovac EV-200 as safety disconnect?
by David Brandt <[EMAIL PROTECTED]>
--- Begin Message ---
>
> Normal... What's that? ;^>
not me :)
>
> Another approach used by some is to use a lightbulb or hairdryer as the
> precharge resistor so that there is a visible (lightbulb goes dim) or
> audible (fan motor slows) signal that precharge has completed normally
> (and audible/visible signs if it doesn't ;^).
that should work. a resistor plus one of the spare lightbulbs on the
dash. I even have one shaped just like a condenser --||--
30 seconds to precharge?
--
Eduardo K. | Some say it's forgive and forget.
http://www.carfun.cl | I say forget about forgiving just accept.
http://e.nn.cl | And get the hell out of town.
http://ev.nn.cl | Minnie Driver, Grosse Point Blank
--- End Message ---
--- Begin Message ---
Chris Tromley wrote:
My LeSled EV (Lectric Leopard based on Renault LeCar, but using 120V
of floodeds) is inching toward full-time use. After my close-to-home
trials the motor is usually too hot to leave my hand on it.
First thought; what gear are you driving in? You need to run at higher
rpms for the internal fan to work effectively. I have the same car, with
a 144v pack and ADC 6.7" L91 motor. I drive in 2nd gear unless I go over
45-50 mph, and the motor is not getting too hot to touch.
I'd like to hook up a blower to extend its life. I have little space,
either for a blower or a larger DC/DC to power it. Questions:
1) I understand a blower is needed rather than a fan (centrifugal or
radial, not axial) in order to generate enough pressure to cram air
through the tight gaps inside a motor. Does anyone know what is an
appropriate flow rate to be effective?
Well, the more the better! But we can't analyze it without data. You
would need to know how many watts of heat the motor is making, and what
temperature rise you want between air intake and exhaust. From that
data, you can determine the needed airflow.
As a practical matter, get a blower and try it. I used a marine bilge
blower on my ComutaVan; it drew about 5 amps at 12v. Your car is bigger
and heavier; but it also has an internal fan in the motor to help -- so
this might work for you as well.
2) I'd prefer that it run from pack voltage to keep the load off my
DC/DC. The descriptions of these motors is generally brief.
If it is a 115 VAC brushed motor, does that mean it's a universal
motor that I can run off DC (with proper DC-rated switching)?
Yes; if it has brushes and a commutator, it's a DC motor. A "universal"
motor (runs on AC or DC) is just a DC motor with a wound field (no
permanent magnets).
If it has a starting cap, does that mean AC only?
Yes; any capacitors on the motor are a good indication that it is an
AC-only induction motor.
So far I've found a few possible candidates. This one is listed as
50/60 Hz with one speed (3400 rpm), so I thought it might be
universal. But that looks like a cap on the side of the motor:
http://www.candhsales.biz/cgi-bin/shop991/shop.pl/SID=1089914489/page=60CB.htm#ACB2300
Yes, that's a cap; it's an AC motor.
Here's one that looks promising, except the flow rate is probably a typo:
http://www.herbach.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=HAR&Product_Code=TM00BLR4428&Category_Code=FAN
That one looks like an AC motor, too.
The search continues. Does anyone have any advice that might narrow
the search?
Look for motors for things like hair dryers, leaf blowers, and vacuum
cleaners, or treadmills. They almost always use brushed DC motors. But
be aware that these consumer products often have noisy, short-lived
motors. Also, many are too big for your application -- you're unlikely
to need more than 1/10th HP.
If you want to power it from the pack, I'd look for a Bodine brushed
motor, and use it to replace the AC motor in one of these squirrel cage
blowers. Bodine makes very high quality, quiet, long-lived motors. For
example, I have a Bodine NSH-34 in my junk box; this is a DC shunt
motor, 4.25" diameter, 5" long, 115vdc, 0.75amps, 1/15hp, continuous
duty, 1725 rpm. Note that since it is a shunt motor, you can control its
speed via the resistance in the field winding.
--
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 ---
Nick wrote:
I just constructed the circuit shown in the email below...
When I fired it up, all three lights come on... if I disconnected
my DC-DC converter, the two red lights would turn off...
I also discovered that when I drive it (without the DC-DC) both
red lights would come on faintly whenever I accelerated (even
slightly). Any recommendations, anyone?
Pack+______________
|
>
red > R1
LED >
___|/|___|
| |\| _|_
Center___| _\_/_ green
tap | | LED
|___|\|___|
|/| |
red >
LED > R2
>
Pack-______________|
There are several things to check.
First, are you tapping your pack to power something? If one part of the
pack has a load that the other part doesn't, it creates and imbalance
which lights the red LEDs.
For example, if you tap the pack at 24v to power the E-meter: The
E-meter has a 1000uF capacitor across its input; that holds the 24v
tap's voltage more stable than the rest of the pack; current spikes from
the DC/DC or controller will shift it less than the part of the pack
without that 1000uF capacitive load, which lights the red "unbalanced" LEDs.
Second, exactly where did you connect the batt-bridge circuit? If the +
or - ends aren't connected directly at the battery terminals, then
voltage drops in the wiring, fuses, shunt, connectors, etc. will shift
the voltage as a function of load current.
For example, if the + wire to the batt-bridge connects at the + input to
the DC/DC converter, then the current spikes drawn by the DC/DC cause
voltage drops in all the wiring between pack + and this point.
Third, the resistors you used for R1 and R2 might be too low a
resistance, making the batt-bridge too sensitive. Try increasing their
value.
Fourth, you might have an unusually noisy DC/DC or controller that
doesn't have filter capacitors on their inputs. You can make the
batt-bridge less sensitive to AC noise by adding a small electrolytic
capacitor across each red LED (10-100 uf is good).
Finally, you may in fact have a weak battery in the pack with excessive
internal resistance. If none of the above helps, look for this!
--
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 ---
Bruce wrote:
Where might one find "conductive grease"?
The grease isn't conductive. It's just supposed to keep water, dirt, and
corrosion out of the connection. Most of the additives and claims are
marketing BS.
--
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 ---
Adrian DeLeon wrote:
EV #2 is going to be a Toyota pickup conversion. 15-20 mile typical
range at 30-45MPH, relatively hilly terrain.
Is that how far you plan to drive it a day, or the limits of the pack
itself (100% DOD at 20 miles)?
1) 9" vs 11" motor. I'm thinking 11" because of the hills. The 11"
should deliver higher torque (at lower RPM) for chugging uphill
and have more power for (occasionally) hauling stuff.
That's not quite how it works. The WarP 9" and WarP 11" have about the
same torque-per-amp (300a vs 260a at 60 ft.lbs, for example). It's your
controller's current that sets your torque limit.
What the bigger motor does for you is lets you run *longer* at higher
currents before the motor overheats.
2) 156V vs 300V battery pack. 156V = 26 x 6V floodies. 300V = 25
x Group 31 AGM, possibly Deka GELs. I know AGMs=$$$, but low
maintenance and higher power are tempting. This will be my
wife's truck, so the closer it matches the original ICE "feel"
the better.
You probably already know this, but...
- The floodeds will be cheaper, last longer, and allow a cheaper
charging system. But they will limit speed and acceleration,
and require maintenance.
- The AGMs will cost more and not last long, and need a more expensive
charging system. But the truck will be fast and powerful, and
the batteries won't require any maintenance.
- The gels will be expensive, but can last as long as the floodeds
if you limit speed and acceleration, and have a more expensive
charging system to avoid overcharging.
--
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 ---
Claudio Natoli wrote:
Hi all,
at the Sydney AEVA workshop last night, I mentioned the EVDL's "1-finger push
test", which our vehicle (Daihatsu Charade) certainly fails.
One thing I've noticed is that, with the front wheels elevated and with the
gearbox in neutral, hand spinning the front (drive) wheels takes considerable
effort. It is difficult to get them up to any sort of speed (ie. 1 rev / sec),
and they stop in a quarter turn or so. By comparison, I recently had
opportunity to try the same thing with an original ICE variant owned by a
friend, and it was considerably easier, and the drive wheel would spin for a
few seconds from a similar speed.
This of course sparked a great deal of curiosity at the workshop, so we jacked
up the front (drive) wheels of our EV, and everyone had a go at turning the
front wheels with a view to seeing whether they thought the friction was high
or normal for a FWD. Typically, opinions varied considerably.
I was therefore wondering whether other owners of FWD EVs, or those with
similar experience, could chip in their 0.2 kh.hrs worth? Does this sound
normal for a FWD? Should the drive wheels spin more freely? Could choice of
gearbox oil, which is the simplest thing for me to change, have a dramatic
impact?
Mine is usually stiff because the disk brakes are always dragging.
When they aren't (for five minutes after cleaning and adjusting them)
you can turn the front wheel with one finger in neutral (and the
opposite side wheel revolves in the opposite direction). If I leave the
opposite wheel down, and with the manual transmission in gear so the
motor is turning, it is stiffer but you can still spin it by hand at a
couple revolutions per second, and it will stop within a revolution or so.
A better way to get an idea how much drag you have, and to gauge whether
changes have helped any is to run the wheels with the motor, and measure
the current it draws. Any change in load is immediately recognizable by
the change in current. As an example, my ADC L91 draws 20 amps just
spinning the flywheel (clutch depressed), 30 amps in neutral (spinning
the transmission input shaft), and 50 amps with both wheels in the air
spinning in 2nd gear and the usual brake drag.
--
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 ---
rod wrote:
Does anyone on the list know how to disable the classic Curtis "Squeal"?
My controller works fine but the squeal is starting to get to me.
The Curtis -C version controllers start off at 1.5 KHz instead of 15
KHz. It makes the motor squeal, but it also starts off smoother. The
circuit change could be removed if you feel up to opening the
controller, but then you may get a starting "lurch" if you have a high
pack voltage and a big motor (like a 144v pack and ADC 9" motor).
--
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 ---
Hello Mark,
A manual transmission is easy to work on. All I needed was a bearing
installer tool that comes in a kit for different sizes of bearings and
seals. The only thing I had to torque was the outside case bolts.
Also a brass hammer with bearing collars for installing the bearings and a
assortment of brass punches.
You should have a inch lb torque wrench for your battery connections anyway.
After I open the cover and remove the tail shaft, sometimes the whole gear
section will slide right out. The shafts that held all the gears were
floating type, which did not need any driving out with a brass punch. I
make my own exploded view blue print of how the parts go together. I also
mark each component with a mark or install a string tag on them and label
them on a blue print.
You will find that the syncro gears are on a separate shaft and you do not
have to remove the main shaft. The syncro shaft was floating which all I
had to do was push the shaft out by hand.
Roland
----- Original Message -----
From: "Mark Farver" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, March 07, 2007 11:42 AM
Subject: Manual Transmission Rebuild
> So I pulled the MR2 transmission last weekend and set it off to a
> transmission shop up here in Austin. They do not even have the tools to
> open it, and they don't have the time to haul it to a shop that
> specializes in manual transmissions. They asked me to come get it, and
> gave me the name of the company (Pistole, in South Austin) that they
> would usually sub the work out to.
>
> The transmission has two problems, a bad 3rd gear syncro (much needed)
> and a metallic rattle that sounds like some loose piece is falling to
> the bottom of the transmission whenever the vehicle comes to a halt.
>
> So now I have a choice, do I haul the tranny to the South end of town
> and pay for a rebuild, or do I do the rebuild myself.
>
> 1. I never even opened a transmission before, and the diagrams make it
> look tremendously complex inside.
> 2. I lack all of the tools required, (including a inch/lb accurate
> torque wrench and a bearing press) as well as several special service
> tools.
>
> OTOH,
> 1. I may save a little money now, and certainly will save money if I
> ever have to do this again
> 2. I can modify the transmission for a electronic speed sensor, and
> maybe even remove unneeded gears like first.
> 3. The factory manual I have covers the entire process, and is very
> complete.
>
> Thoughts? Anyone ever done this before?
>
> Mark Farver
>
>
--- End Message ---
--- Begin Message ---
> I had a friend who saw I think a Honda hybrid car prototype being called
> "Impact".
> She said she joked to the guy doing the demo about that name and he said
> other people had said the same thing, but he didn't understand the
> problem. It was meant to make an impact on the market or something.
>
> Danny
Hmm... sort of like a Korean car named KIA? Not a great name for those old
timers who associate Korea with a war.
Of course I had a similar reaction to an electric named BugE (buggy). <g>
--- End Message ---
--- Begin Message ---
At 02:01 PM 7/03/07 -0600, you wrote:
rod wrote:
Does anyone on the list know how to disable the classic Curtis "Squeal"?
My controller works fine but the squeal is starting to get to me.
The Curtis -C version controllers start off at 1.5 KHz instead of 15 KHz.
It makes the motor squeal, but it also starts off smoother. The circuit
change could be removed if you feel up to opening the controller, but then
you may get a starting "lurch" if you have a high pack voltage and a big
motor (like a 144v pack and ADC 9" motor).
G'day Lee, and All
Would adding an inductor in series fix the lurch?
Regards
[Technik] James
--- End Message ---
--- Begin Message ---
How does one go about choosing the right diodes for a rectactor circuit. I
have a saved copy of a circuit that Lee Hart posted and some big new
surpluss conatactors I bought off of Ebay. I want to build the circuit and
watch it work, probably with a coat hanger and a bucket of water to start
off with, but I have not worked with big diodes before and I don't know what
specs are important to look at. I have been up on mouser.com looking around
and seen several that look like good candidates to me, but it is a somewhat
uneducated guess on my part.
Here is one that looked reasonable. Am I in the ballpark? Mouser part
#RHRG75120.
damon
_________________________________________________________________
Mortgage rates as low as 4.625% - Refinance $150,000 loan for $579 a month.
Intro*Terms
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--- End Message ---
--- Begin Message ---
I'm mounting my Curtis ( 1221C) to a flat aluminum plate ( 3/16 x 14 x 16
inches) as a heatsink, but I also have a smaller, finned heatsink ( about 5
x 7 x 2 inches) that I want to mount to the back side of the plate.
(opposite side as the controller) for a bit of extra cooling.
I may as well put it close to where the heat is generated on the Curtis"
base - it would probably be a bit more effective. My guess is that the heat
generating components are close to the end with the large power terminals.
Is that right?
Does anyone know where the internal heat-generating components are? Or, have
a picture of the guts of a 1221C that would show that?
Thanks
Phil
_________________________________________________________________
Mortgage rates as low as 4.625% - Refinance $150,000 loan for $579 a month.
Intro*Terms
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--- End Message ---
--- Begin Message ---
> I think the problem with the subaru, correct me if I'm wrong, is that they
> are all either all wheel drive vehicles or 4WD. EVERY Subaru is like
> that.
> Thus you have a greater drain on the batteries. Of course you could just
> replace the transmission.
>
> Bill
The older models have a 2nd lever to engage 4WD.
--- End Message ---
--- Begin Message ---
my '86 and I think others of that era, used a 5th gear in the tranny for a
takeoff for the rear wheels IIRC.
This means that in 2wd its a FWD car. You could just remove that rear wheel
drive hardware.
if this helps at all- maybe the 80's ones were sold in salt&snow country and
are all rusted out.
Michael wrote:
The older models have a 2nd lever to engage 4WD.
--- End Message ---
--- Begin Message ---
Frank John wrote:
I *think* I understand the purpose/need for precharging but would
appreciate an experts overview, especially as it relates to use of
the Curtis potbox switch. This would be with the SW series contactor.
Most controllers have a *huge* bank of capacitors with very low
equivalent series resistance on their input. Most batteries likewise
have a very low equivalent series resistance. If you switch the
controller directly to the battery with nothing but a contactor, a
*huge* inrush current will flow, trying to charge those capacitors
instantly. The contacts are overstressed, and will wear out and fail early.
A precharge circuit is any circuit that allows the controller's
capacitors to be charged up to pack voltage *before* the contactor
closes. Usually, it is nothing but a resistor and a small switch or
relay, closed for a second or so to charge up the 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 ---
Bill Dube wrote:
It is "penny wise and pound foolish" to implement a continuous
balancing system that pushes around a large number of amps. Once you
do the accounting, you discover that it costs you more than you save
if you push around much more than an amp with a continuous type BMS.
I've found that there *are* cases where you want to move a significant
number of amps for a significant time.
It is quite common to have a set of perfectly good batteries whose
amphour capacities differ by +/-10%. For example, they might average
50ah, but the best is 55 ah and the worst is 45ah at the 1-hour rate.
Let's say your commute takes an hour. Without balancing, you only have
45ah; you're limited by the weakest battery. It gets more deeply
discharged than the rest, so (all things being equal) it will fail sooner.
Now suppose you have a balancer that can move 5 amps for 1 hour. At the
start of your drive, it can be pulling 5 amps from the best battery and
using it to charge the worst one. At the end of your 1-hour commute,
both batteries are at the same depth of discharge, so you aren't
hammering the weak link to an early demise. Your range has been extended
10% because you are no longer limited by the weakest link.
That's good! The tradeoff is economic. You have to look at what the
balancing system costs, and how much it adds to your range and life. I
can't say how it will work out for everyone, but in my own case, I
figure my balancer cost $1000, but doubled the life of a $1500 pack; so
I'm money ahead.
and about Cor van de Water's reply, Bill wrote:
Your reply makes no sense to me. I don't think you understand what
is commonly meant when we speak of a "BMS."
His reply made sense to me, Bill. You may want to reread it before being
so dismissive. Both of you basically said the same things; I didn't see
any points of disagreement except semantics. For instance:
Cor: Most BMS systems address this by applying a slight over charge
to all the batteries.
Bill: The charger provides the current for charging (and purposeful
overcharging) not the BMS.
Cor is just including the charger in his definition of a "BMS System" --
like a Rudman PFC charger with Mk3 regulators.
A continuous system has all day and all night to transfer the
expected amp-hr imbalance. Thus, a fraction of an amp is all that
is typically needed.
It depends on the batteries, and how far out of balance they are. Little
AGMs are one thing; big floodeds are another. There can also be
temperature differences, or a new battery in an older pack, or just
differences in each battery's basic capacity as in the example above.
--
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 ---
> A manual transmission is easy to work on. All I needed was a bearing
> installer tool that comes in a kit for different sizes of bearings and
> seals. The only thing I had to torque was the outside case bolts.
>
> Also a brass hammer with bearing collars for installing the bearings
and a
> assortment of brass punches.
>
>
Is it still that easy with a mid-engine car like an MR2?
--- End Message ---
--- Begin Message ---
> I've seen these before but I just noticed for the first time some of the
> interesting instrumentation they have. Did anyone else notice the
"distance
> to empty" gauge on it? That's really cool. Is there anything like it
> available that I could put in my truck? If not, does anyone have
any good
> ideas on how to make one?
>
The DTE gauge may take up as much space as the speedometer, but I go
by the "fuel tank" type meter for the true capacity level. That
"Distance to Empty" will vary based on previous trip range and current
driving conditions, so it is more like an analog equivalent to the
EV1's digital range reading - there's nothing on the market like it
for a generic EV installation. A Link-10/e-meter is as close as
converters get.
--- End Message ---
--- Begin Message ---
Nick wrote:
Do you think I could achieve the same effect by putting a single
capacitor across the green LED?
No. If you're just getting momentary lighting of the red LEDs, then the
capacitors have to go across them.
--
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 ---
Well, I've been wanting an e-meter anyway, but the DTE gauge would make my
wife feel better, I think. :)
On 3/7/07, Death to All Spammers <[EMAIL PROTECTED]> wrote:
> I've seen these before but I just noticed for the first time some of the
> interesting instrumentation they have. Did anyone else notice the
"distance
> to empty" gauge on it? That's really cool. Is there anything like it
> available that I could put in my truck? If not, does anyone have
any good
> ideas on how to make one?
>
The DTE gauge may take up as much space as the speedometer, but I go
by the "fuel tank" type meter for the true capacity level. That
"Distance to Empty" will vary based on previous trip range and current
driving conditions, so it is more like an analog equivalent to the
EV1's digital range reading - there's nothing on the market like it
for a generic EV installation. A Link-10/e-meter is as close as
converters get.
--- End Message ---
--- Begin Message ---
Death to All Spammers wrote:
Is it still that easy with a mid-engine car like an MR2?
The driveline of the mid-engined MR2 is essentially that of a FWD
Corolla from the same time period except the entire suspension and
transmission has been moved to the rear of the vehicle. Even the wheel
hubs are identical with rigid tie rods replacing the steering box.
(I've always thought it would be a great car to retrofit rear wheel
steering onto. The transmission is a stock Toyota FWD transaxle with a
minor change to move the shift cables to the front side.
Mark
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Hi all,
I tried Cor's recommendation of a small electrolytic capacitor (1 uF)
across the red LEDs and it brought them down to a barely perceptible
glow. I haven't wired it into the circuit permanently yet (waiting for
the rain to stop outside!), but I think that has done the trick. I
checked everything Lee mentioned, but I guess I just have a noisy DC-DC
converter. It is a Lambda module that I mounted on a home-made circuit
board - I don't remember adding any input capacitors to it, I guess I
should have.
Thanks,
Nick
Lee Hart wrote:
Nick wrote:
I just constructed the circuit shown in the email below...
When I fired it up, all three lights come on... if I disconnected
my DC-DC converter, the two red lights would turn off...
I also discovered that when I drive it (without the DC-DC) both
red lights would come on faintly whenever I accelerated (even
slightly). Any recommendations, anyone?
Pack+______________
|
>
red > R1
LED >
___|/|___|
| |\| _|_
Center___| _\_/_ green
tap | | LED
|___|\|___|
|/| |
red >
LED > R2
>
Pack-______________|
There are several things to check.
First, are you tapping your pack to power something? If one part of the
pack has a load that the other part doesn't, it creates and imbalance
which lights the red LEDs.
For example, if you tap the pack at 24v to power the E-meter: The
E-meter has a 1000uF capacitor across its input; that holds the 24v
tap's voltage more stable than the rest of the pack; current spikes from
the DC/DC or controller will shift it less than the part of the pack
without that 1000uF capacitive load, which lights the red "unbalanced"
LEDs.
Second, exactly where did you connect the batt-bridge circuit? If the +
or - ends aren't connected directly at the battery terminals, then
voltage drops in the wiring, fuses, shunt, connectors, etc. will shift
the voltage as a function of load current.
For example, if the + wire to the batt-bridge connects at the + input to
the DC/DC converter, then the current spikes drawn by the DC/DC cause
voltage drops in all the wiring between pack + and this point.
Third, the resistors you used for R1 and R2 might be too low a
resistance, making the batt-bridge too sensitive. Try increasing their
value.
Fourth, you might have an unusually noisy DC/DC or controller that
doesn't have filter capacitors on their inputs. You can make the
batt-bridge less sensitive to AC noise by adding a small electrolytic
capacitor across each red LED (10-100 uf is good).
Finally, you may in fact have a weak battery in the pack with excessive
internal resistance. If none of the above helps, look for this!
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Peter VanDerWal writes:
> If it stops within 1/4 revolution, then I think you have a
> problem with drag and I don't think it's the oil (or at
> least not mainly).
That matches my intuition; however, after a full trip the gearbox gets warmer
than I would have expected, and since it is an easy change I'll make it
regardless.
> Have you tried prying the brake pads back from the disc to
> see if they are dragging? Perhaps you have a warped
> disc, does the wheel stop in about the same position each time?
I will try this, and also mark the wheel to see if there is any repeated
behaviour.
> Have you tried it with the clutch disconnected? If it spins
> much easier with the clutch disengaged, that might indicate a
> misalignment between the motor and the transmission.
Sorry, should have mentioned that we're running clutchless.
Thanks for the input,
Claudio
Sydney AEVA - for Electric Vehicle enthusiasts in Sydney, Australia
http://sydneyaeva.googlepages.com/
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Roger Stockton writes:
> > Could choice of gearbox oil, which is the simplest thing for
> > me to change, have a dramatic impact?
>
> If you are running stock oil in the EV and ICE vehicles that you
> compared, then while better/lighter oil might make a difference, it
> doesn't explain the difference between the two.
Right.
> If you don't spend a great deal of your driving time running
> in neutral, there may be little benefit to addressing the amount of
> energy it takes to spin things in neutral. ;^>
Not for very long or far :-) But it is indicative.
> It might be more productive to see how difficult it is to
> spin the wheel with the tranny in gear and the clutch
> disengaged, and compare this to the ICE version.
I did try this also with the ICE, and found a similar disparity.
> Brakes are the easiest to check, since you can simply pry the
> pads away from the rotors (if disk brakes),
Will do.
> If you've got instrumentation you can quantify the difference
> in power easily, otherwise using a torque wrench or spring scale,
> etc. to apply the force required to turn the wheel will let you
> get a feel for the qunatitative improvement.
I will be sure to make quantitative measurements before I start, and between
each step. Thanks for the reminder.
> An IR thermometer seems like a great way to find out where the losses
> are; jack up the drive wheels and spin them for awhile, then check to
> see what's getting warm.
That's an interesting idea too. I'll try that if/when I track one down.
Thanks again,
Claudio
Sydney AEVA - for Electric Vehicle enthusiasts in Sydney, Australia
http://sydneyaeva.googlepages.com/
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Lee Hart writes:
> > I was therefore wondering whether other owners of FWD EVs, or
> > those with similar experience, could chip in their 0.2 kh.hrs
> > worth? Does this sound normal for a FWD? Should the drive wheels
> > spin more freely? Could choice of gearbox oil, which is the
> > simplest thing for me to change, have a dramatic impact?
>
> Mine is usually stiff because the disk brakes are always dragging.
>
> When they aren't (for five minutes after cleaning and adjusting them)
> you can turn the front wheel with one finger in neutral (and the
> opposite side wheel revolves in the opposite direction). If I
> leave the opposite wheel down, and with the manual transmission
> in gear so the motor is turning, it is stiffer but you can still
> spin it by hand at a couple revolutions per second, and it will
> stop within a revolution or so.
That sounds a good deal better than mine. It also sounds like I'll need to
recheck some time after adjustment to see how the changes hold up. Would
changing brake hoses help prevent yours from unduly dragging after adjustment?
> A better way to get an idea how much drag you have, and to
> gauge whether changes have helped any is to run the wheels
> with the motor, and measure the current it draws. Any change
> in load is immediately recognizable by the change in current.
> As an example, my ADC L91 draws 20 amps just spinning the
> flywheel (clutch depressed), 30 amps in neutral (spinning
> the transmission input shaft), and 50 amps with both wheels
> in the air spinning in 2nd gear and the usual brake drag.
Will do Lee. Suspecting you have a problem from a qualitative observation is
one thing, but I've found that doesn't work so well when trying to judge if
you're fixing things. "Is it a little better? I think so... am I fooling
myself?" I'll take measurements along the way.
Thanks again,
Claudio
Sydney AEVA - for Electric Vehicle enthusiasts in Sydney, Australia
http://sydneyaeva.googlepages.com/
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--- Begin Message ---
James Massey wrote:
Would adding an inductor in series fix the lurch?
Inductance alone won't fix it; the lurch occurs because at 15 KHz, the
minimum on-time of a Curtis controller results in about a 5% duty cycle.
5% of a 144v pack is 7.2v at the motor. A 9" motor doens't turn very
fast at 7.2v, but it can easily draw 500 amps. *That's* what makes the
lurch!
So, a quick and dirty way to kill the whistle is to insert some
resistance in series with the motor when first starting out. Once the
motor starts to turn a bit, you can short this resistance with a contactor.
--
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
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--- Begin Message ---
Well the Chevy Nova was a joke in Spanish-speaking countries, since "no
va" would be "doesn't go".
If I remember my Spanish, an implied subject is normal, so this is even
a complete sentence- "(it) doesn't go (run/move)".
Danny
Michael wrote:
I had a friend who saw I think a Honda hybrid car prototype being called
"Impact".
She said she joked to the guy doing the demo about that name and he said
other people had said the same thing, but he didn't understand the
problem. It was meant to make an impact on the market or something.
Danny
Hmm... sort of like a Korean car named KIA? Not a great name for those old
timers who associate Korea with a war.
Of course I had a similar reaction to an electric named BugE (buggy). <g>
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You could join the ranks of the John Waylands of the world or get used to
it. As long as you have that setup it will squeel and there is little you
can do about it. Lawrence Rhodes.......
----- Original Message -----
From: "rod" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, March 07, 2007 6:37 AM
Subject: Curtis 1231C squealing solution
> Does anyone on the list know how to disable the classic Curtis "Squeal"?
> My controller works fine but the squeal is starting to get to me.
>
> Regards, Rod Dilkes
> www.dilkesmotors.com
>
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Earplugs??
On 08/03/07, Lawrence Rhodes <[EMAIL PROTECTED]> wrote:
You could join the ranks of the John Waylands of the world or get used to
it. As long as you have that setup it will squeel and there is little you
can do about it. Lawrence Rhodes.......
----- Original Message -----
From: "rod" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Wednesday, March 07, 2007 6:37 AM
Subject: Curtis 1231C squealing solution
> Does anyone on the list know how to disable the classic Curtis "Squeal"?
> My controller works fine but the squeal is starting to get to me.
>
> Regards, Rod Dilkes
> www.dilkesmotors.com
>
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--- Begin Message ---
Hello I am researching building my electric car and I was wondering
whether anyone could recommend some reading material for me. I have
Convert It, Electric Vehicle Technology Explained, and Building your
own Electric Car. I am specifically interested in AC motors and Lithium
Ion tech. Thanks.
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--- Begin Message ---
Roger wrote:
"Is there any possibility that you had one of the contactors wired in
reverse polarity? Not the coil, but the main contacts; they are
polarised, and the switch life is *dramatically* reduced if connected in
reverse polarity. According to the datasheet, life is about 12 cycles @
200A if connected in reverse polarity vs 50,000 at about 350A when used
in the correct orientation, according to the 90% precharge capacitive
inrush spec."
Nope. I observed the polarity markings.
"Are you sure your precharge circuit was working the way you intended?
This failure is also what one would expect if, for example, the
contactor with the precharge relay were closing immediately, and the one
without was then closing afterwards."
Nope, they closed in the proper sequence, with about a 2 second delay.
"In a nutshell, the contactor with the precharge resistor across it
couldn't possibly precharge anything unless the other contactor was
closed first, and if the first one closes while the other is open, then
it could not see much of an inrush at all."
Yes. The one without closed first. A relay then closed to apply power to the
second when the controller voltage rose to a set level. I don't remember where
I had it set, but it was at least 90%.
"Many precharge systems actually use a small 10A (P&B KUEP, etc) relay in
series with the precharge resistor so that when the ignition is off the
controller is completely disconnected from the traction battery, and if
these little relays can handle the inrush that your first EV200 would be
switching, then there is no way the EV200 can't."
Unless the EV200 was bad to begin with.
"If the EV200s were closing in the proper sequence, then the contactor
that should see the most stress is actually the second one to close..."
Agreed. However, it shouldn't have been under too much stress either.
> The newer EV-200 model (I forget the model designation - You
> can probably find it on the tyco electronics website) is
> twice as tall. I suspect they had minimal gaps and realized
> that to market the new model for aircraft, as they do, that
> they had to have better reliability, so they increased the
> travel of the contacts.
"Actually, the newer LEV200 is only 3" tall vs 2.04-2.2" for the older
EV200, and carries identical ratings. It is grouped under "Aerospace,
Ground Power and Industrial High Performance Contactors", but is
identified as an "Industrial DC Contactor"."
That's the one I was thinking of. So it has about a 30% increase in height.
That's significant.
"The CAP200 appears to be the aerospace counterpart and MAP200 is the
MIL/aerospace counterpart. Both of these parts appear to have similar
dimensions as the smaller EV200 rather than the larger LEV200 part..."
I wonder what aerospace companies have used it and if they have had good
reliability.
____________________________________________________________________________________
Get your own web address.
Have a HUGE year through Yahoo! Small Business.
http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
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