EV Digest 5073
Topics covered in this issue include:
1) Re: Fw: Geo Metro EV on a budget
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
2) Re: I want to build a PWM DC motor controller
by Nick Viera <[EMAIL PROTECTED]>
3) Re: I want to build a PWM DC motor controller
by Lee Hart <[EMAIL PROTECTED]>
4) Re: I want to build a PWM DC motor controller
by Lee Hart <[EMAIL PROTECTED]>
5) Re: EMeter quirks
by "John G. Lussmyer" <[EMAIL PROTECTED]>
6) 9" ADC motor mount
by Ken Albright <[EMAIL PROTECTED]>
7) Initial NiCd test run on my Sparrow
by "John G. Lussmyer" <[EMAIL PROTECTED]>
8) Re: honda hub adapters - any vendor done these?
by Bob Bath <[EMAIL PROTECTED]>
9) Re: I want to build a PWM DC motor controller
by Stefan Peters <[EMAIL PROTECTED]>
10) Re: I want to build a PWM DC motor controller
by Stefan Peters <[EMAIL PROTECTED]>
11) Tire Ignition Sequence Photos of White Zombie???
by John Wayland <[EMAIL PROTECTED]>
12) float voltage...and emeter and questions...
by Dave <[EMAIL PROTECTED]>
13) Re: I want to build a PWM DC motor controller
by Lee Hart <[EMAIL PROTECTED]>
14) Re: Federal EV tax credit
by Lee Hart <[EMAIL PROTECTED]>
15) Re: 9" ADC motor mount
by Jim Husted <[EMAIL PROTECTED]>
16) Re: 9" ADC motor mount
by [EMAIL PROTECTED]
17) Re: EMeter quirks
by James Massey <[EMAIL PROTECTED]>
18) Re: EMeter quirks
by Christopher Zach <[EMAIL PROTECTED]>
19) Re: Federal EV tax credit
by paul wiley <[EMAIL PROTECTED]>
20) Re: Fw: Geo Metro EV on a budget
by "Joe Strubhar" <[EMAIL PROTECTED]>
21) Re: I want to build a PWM DC motor controller
by Stefan Peters <[EMAIL PROTECTED]>
22) Re: I want to build a PWM DC motor controller
by Cory Cross <[EMAIL PROTECTED]>
23) Re: Motor Shafts
by Ryan Stotts <[EMAIL PROTECTED]>
24) Re: Motor Shafts
by Jim Husted <[EMAIL PROTECTED]>
25) Re: float voltage...and emeter and questions...
by Bob Bath <[EMAIL PROTECTED]>
--- Begin Message ---
That's very good. I run 70 to 80 amps going 45mph in third gear with a
120vdc system. Note my car weighs 1000 pounds more than Bill's VW.
----- Original Message -----
From: "Bill & Nancy" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, January 08, 2006 11:39 AM
Subject: Re: Fw: Geo Metro EV on a budget
I'm running 72 volts, 40mph in 2nd and 45 mph in 3rd @100 amps.
Bill
jmygann wrote:
How fast can you go @ 100 amps ? How many volts ?
--- In [EMAIL PROTECTED], Bill & Nancy <[EMAIL PROTECTED]> wrote:
1 hr rating @ 200 amps. I hadn't even considered the controller
specs.
It is best for pack longevity to keep running amps below 100? Just
learning as much as I can about driving the vw and the most efficiant
operating range.
--- End Message ---
--- Begin Message ---
Stefan Peters wrote:
I'm still figuring that out with these posts ;)
Stefan, it looks like you're also figuring out time travel... as you're
posts are now being dated about a month in the future. ;-)
For people with a date-sorted E-mail Inbox, that puts (and keeps) every
one of your e-mails at the top of the list...
--
-Nick
1988 Jeep Cherokee 4x4 EV
http://go.DriveEV.com/
http://www.ACEAA.org/
--------------------------
--- End Message ---
--- Begin Message ---
Danny Miller wrote:
> Can't parallel diodes, not without an additional series resistance in
> front of each one. Voltage vs temp coefficient will make the warmest
> one end up taking all the current and overheat it.
You'll notice that they do it anyway. They match the diodes to all have the
same forward drop at current, and mount them all on a common heatsink to hold
them at the same temperature. This is one of the little details that a home
builder is likely to miss.
The correct approach for a home builder is to use a single big diode to avoid
this problem.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Danny Miller wrote:
> It doesn't seem very accurate to me to describe Peukert's this way.
> I have been trying for a long time to find an authoritative description
> of Peukert's. I don't dispute the equation but I have never seen a
> thorough explanation that fully answers my questions. It stops short of
> explaining variable loads for one.
Peukert's equation is subjective; it's based on test data, not on theory. That
is why it is just an equation, not a law (like Ohm's Law).
Peukert just measured actual battery amphour capacity at various load
currents, then plotted the data (capacity vs load current), and calculated
the coefficients for an equation to fit the curve. His equation can then be
used to estimate capacity at other load currents.
The same thing works when you have pulsed loads. For instance, discharge the
battery at various average currents, but using a pulsed load (like a GE EV1
controller and motor instead of a fixed resistor). Now your battery current
is in pulses, not pure DC.
Compare the capacity vs. load current curves for DC loads, and for pulsed
loads. What you will find is that the higher the peak current, the lower the
amphour capacity even if the average current is the same. Peukert's equation
works best when you use the peak current rather than the average current.
To use Peukert's equation with pulsed loads, measure the battery current
periodically (like once every second). Each second, use Peukert's equation to
compute the corrected number of amphours removed during that second. Total up
these amphours to get the cumulative capacity.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
At 12:28 PM 1/8/2006, John G. Lussmyer wrote:
I've just finished re-connecting everything and am working on
charging my NiCd pack in my Sparrow.
One thing I've noticed is that the EMeter current reading is about
15-20% higher than my Analog ammeter I have on the charger
shows. (Analog meter was showing 21A, EMeter was 24.4A). Checking
mv across the
Well, on closer examination, I may have found the problem.
The charger connection to the negative line is at the shunt. The
charger wire doesn't have a large enough lug to fit the big honkin
bolt on the shunt, so it is mounted on the sense bolt. I think this
is causing the problem. I'm going to find a big lug and mount the
charger to the main connection bolt.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
I just got the motor attached to the transaxle and stuffed into the '86 VW
Scirocco I'm converting (Hooray!). I'm reusing the three mounts that attach to
the tranny. For the motor end I'm still scratching my head.
The brush end of the motor has two 3/8" holes that look like they could be
used to attach a mount similar to the EA mount for the 8" motor. However, due
to the orientation, reusing the ICE motor mount location may cause sheer
stress on the bolts/holes. That is to say, when looking at the brush end of
the motor, the holes are at 2 and 4 o'clock and the existing mount location on
the body is over the 9 o'clock position. Anyone know how strong these holes
and the end plate are and how much stress would be placed on them?
Alternatively, is anyone making an end mount for the 9" motor?
I have the big belly band strap as supplied by KTA which I may end up using
by welding a connection between it and the ICE motor mount. However, that
seems like an inelegant solution.
Thanks
Ken
---------------------------------
Yahoo! Photos
Got holiday prints? See all the ways to get quality prints in your hands ASAP.
--- End Message ---
--- Begin Message ---
I just put about 10 miles on the bird with the NiCd pack. Here are
the results.
(Note that the Sparrow has been sitting unmoving for most of a year...)
I had the EMeter set for 40AH (which seems to be pretty close to the
actual capacity of these BB600 cells.)
Charged to 205V (PFC-20). 20 minutes after the charger was
disconnected the voltage was 195V. (I have to stay under 200V before
turning on the DCP Raptor controller!)
137 cells for a 164V nominal pack.
Drove up and down a side street here - since my license tabs are expired.
10.2 miles of up/down gentle hills, no real level area.
EMeter said 46% remaining (of what?), Used 2.35KWH. (NOT AH)
My low-cell monitor would complain when I pulled over about 150A. A
total 6 cells had gone low out of the 72 in the front pack. I
couldn't hook up the monitor to the 65 cell under-seat pack due to a
wiring problem.
They didn't stay low (< 1.0v), just went low during acceleration.
Pack was at 174V resting afterward.
Does 230 WH/Mile sound reasonable for a Sparrow?
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
Hmmm. My former engine was a B16 (92 Civvy), but it
was an s20 transmission. Maybe I need more
information. Nels Strandberg made mine and Lynn Adams
(also a LISTer), but ElectroAutomotive is also a good
source-- they contract out for adapter plates,
including Honda models. Are you sure it's an SC4?
--- Monty McGraw <[EMAIL PROTECTED]> wrote:
> I've got a Honda B16 SC4 5-speed manual
> transmission. I'd like to get an
> adapter made for an Advanced DC Motor, I think the
> 8" motor is the best fit.
>
> Is there any vendor that has done Honda transmission
> adapters?
>
> Thanks,
>
> Monty McGraw
> Spring, TX
>
>
'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?
__________________________________________
Yahoo! DSL Something to write home about.
Just $16.99/mo. or less.
dsl.yahoo.com
--- End Message ---
--- Begin Message ---
Roger Stockton wrote:
I think you have to consider the BMS functionality as a side
benefit/feature and assume that those who consider your system will do
so because they can build your *controller* cheaper than they can
build/buy a conventional controller. After all, their EV is useless
without a controller, but is perfectly usable without a BMS.
Unfortunately, I think that looking just at cost it would be cheaper for
a hobbiest to build a basic PWM controller (and easier too).
You have a good point. You did see where I said you don't have to use
any Power Modules at all?
I'm actually quite in favor of a good, simple analog PWM DIY controller.
I actually have linked to a few good well-tested robotics ones from
EVForge.net that could be scaled up (with some paralleling and such). I
just go where my passion is, and I personally like having alternatives.
I am hoping that others can use parts of this project to create PWM
controllers. If someone took a Power Module and removed the bypass
diode, added some smoothing caps with precharging, they should have a
perfect usable PWM controller (for lower voltages).
The names you have assigned your blocks ("Power Modules", "Subnet
switch", etc.) sound impressive, but really don't tell me anything about
what they do or how my EV traction wiring would look with them vs a
conventional PWM controller or a conventional contactor controller, etc.
I have linked the system diagram in this thread before. The names are
just for my own thought processes, I find that using pronouns is very
helpful when designing systems that have interrelated pieces. The "Speed
Controller" is a simple micro-controller motherboard with a bus driver.
The "Data Bus" is a four-wire type with 5V supply (for the micros in the
other modules). The "Subnet Switch" is anything capable of performing
series/parallel switching (currently a set of SPDT contactors run from a
PIC with driving transistors). The "Power Modules" are taken from the
BatPack prototype setup at RedRock EV (MOSFET switch with bypass diode),
with isolation and a small PIC added. I have linked in a schematic of
the power stage of those before as well.
There is a long rambling with various explanations, diagrams, and
testing schematics at EVForge.net:
http://www.evforge.net/forum/viewthread.php?forum_id=13&thread_id=10
My main concern is that I *think* you envision being able to switch each
battery individually into or out of the traction pack,
That is what the BatPack style Power Modules do. But only in series.
and doing so in
such a way that each battery may be placed in series or in parallel with
the other batteries in the string. This ability is required since you
must be able to place the batteries in series to achieve the higher
voltages required for higher speed operation, and you must be able to
place the batteries in parallel if you are to achieve the lower-per
battery current draw that a PWM controller provides at low motor
voltage/high motor current operation.
The "Subnet Switch", or micro-supervised contactor controller, does what
contactor controllers always do: switch a couple strings in
series/parallel configurations. It also is were the motor
voltage/current and other such sensors would be installed.
This suggests to me a nightmare of high current wiring and fairly
complicated switching capability at each battery, with all the losses
that the switches and extra connections entail. And, don't forget that
the 2/0 cable and terminals typically used to interconnect our traction
batteries are neither particularly light or cheap.
See the diagram. It is the same HV wiring that many are familiar with.
If you wish to use the Power Modules, just mount them to each battery
(they are the size of a smaller hardbound book, getting ready to start
testing various mounting options). There is a BAT- and a BAT+ input, a
OUT- and OUT+ output (treat them just like the battery terminals when
connecting in a string), and two modular plugs for the data bus. You
daisy-chain the data bus from module to module.
So a two string setup of 4 batteries each would have the same amount of
HV wiring (plus the couple of inches to the modules from the battery) as
any dual string EV. Just some shielded 4 wire (shielded CAT5 is actually
easier to get these days, that is what I'm using) cable from module to
module added.
It also suggests to me that each battery must be charged individually;
i.e. the "rest" state of the system is with all batteries disconnected
from one another. Certainly, if one took advantage of your system to
mix and match batteries of different types or size they could not charge
them in a series string even if the controller was willing to connect
them in such a way for charging.
That came up earlier in the thread. Using the Power Modules does present
difficulties with string charging. But why is charging each battery
individually so bad?
Finally, the use of switches at each battery implies to me much higher
losses than a conventional system. Consider the specs for a Curtis
1231C (a common PWM controller, but hardly state-of-the-art): 0.30V drop
per 100A, 550A maximum (72-120V model). This would be 1.65V drop @
550A. Let's assume the 120V pack sags to 117V at this load, so 1.65V
corresponds to about 1.4% loss.
What sort of loss would your system have at 550A if the pack were
composed of 10 12V batteries? How about if it were composed of 20 6V
batteries (the battery of choice for cost-conscious EVers)?
This has also been traveled over (in much detail) earlier in the thread.
I won't post all the numbers again, just wasted bandwidth. One of the
reason why RedRock EV started playing with the BatPack idea was to lower
those darn switching losses for racing applications. The Rds of a 500A
module that is switched on will be 1.2 milliOhms. The forward voltage
drop of a module when it is switched off (bypassing the battery) would
be 1.35V. If you arrange the 6V batteries in threes for 18V each (the
current max recommended for the silicon in the Power Modules), you would
have six in a two string 54/108V or eight in a four string 74/144V pack.
Obviously, you would want to run as many Power Modules in the on state
as possible.
Of course; it is not an "electronic" task to flash a micro. It is not a
matter of what is harder to do, but rather what one is comfortable with.
I think a lot of EV hobbiests are far more comfortable soldering and
bolting things together according to provided instructions than using PC
to flash a micro, even if flashing the micro is actually a simple task.
Hmmm... I will have to focus on making that part as simple as possible
in any future documentation. That is a good thing to keep in mind.
I'd really like to see schematics for your system (don't bother with the
details of the micros or exact FET configuration even, just show a
little box for each of your modules and include standard switch symbols
with appropriate connections to the traction wiring in place of each
FET/contactor, etc.). I have this feeling that it will make the Curtis
schematic look like child's play, but perhaps you will set me straight.
I'm doing an detailed diagram right now (showing each part of the system
diagram like that). I will be posting it at the above mentioned forum.
Each Module only has a couple of boxes ;)
Unless you start by populating your traction pack with random mismatched
batteries scaveged from here or there, you always start off with a
pretty matched set of batteries. If the controller discharges them
equally and they are recharged equally then they tend to remain fairly
well matched over most of their usable life.
I've heard some horror stories, as well as many that run just as you
say. Then there are batteries that plain go "bad" early (location issues
with temperature, bad manufacturing), and what about upgrading the pack
with more batteries part-way through it's lifetime? Guess that is what
long-term on-road testing will help show.
Sounds good to me. I don't mean to sound like I'm trying to discourage
you; I just want to understand what it is you are building and to try to
understand how it compares to the alternatives. Only then can I
appreciate what sort of advantages it might offer.
I would strongly recommend going through the forum as well as reviewing
this thread on EVDL.
The beauty of computers is that you can approximate the effects of very
complicated discrete circuitry with hardly any hardware. The algorithms
you use are the key to this ability. The downside (as Lee and others
have pointed out) is that you have to be very careful with all this
flexibility and "power", as the more things you can potentially do, the
more things there are to potentially go wrong. Which is why I suppose
the software side of this "open-source" project will hopefully only be
fiddled with by those with some professional experience. The hardware on
the other hand is pretty darn simple, even for a casual electronics
newbie like me ;)
--- End Message ---
--- Begin Message ---
Nick Viera wrote:
Stefan Peters wrote:
I'm still figuring that out with these posts ;)
Stefan, it looks like you're also figuring out time travel... as
you're posts are now being dated about a month in the future. ;-)
For people with a date-sorted E-mail Inbox, that puts (and keeps)
every one of your e-mails at the top of the list...
LOL, sorry about that. Seems to be a running gag with me :(
I have gone and setup NTP clients on all of my computers at home,
pointed to pool.ntp.org.
--- End Message ---
--- Begin Message ---
Hello to All,
Concerning the DragTimes.com web page for White Zombie, in late December
I had written:
>If any list members have a good photo of WZ they'd like to see there
instead, send it to me, and I'll pick my favorite of what I receive and
>resend it to the site.
I've just received a very nice email from Brooks again, this time about
his feelings that WZ will indeed, be the February Timeslip car of the
month. He's made a generous offer to make up a nice combination collage
type photo for the car to properly introduce the gasser crowd to fast
electrics. He's going to take a smoking tires type picture of my choice
as the main photo and will add in my photos of the motor bay, battery
pack, and perhaps a few side shots of the car as well. Which brings me
to the point of this email....
Each year I've had White Zombie at the Woodburn drags, there's been at
least 10 different folks with digital cameras snapping pictures of the
car, especially whenever I would do my signature burnouts. And yet, now
about two weeks after asking for photos from those who were there,
there's been nothing but tumble weeds blowing by.....I received exactly
one picture, but it wasn't a real action type photo.
Come on everyone, here's your chance to have your photo up for all to
see for a long, long time at the DragTime.com web page.
So.....I'll ask again. Anyone out there with a clean digital photo of WZ
baking its tires? In particular, the most recent 2005 Woodburn EVent
where Tim lit 'em pretty good on many occasions. The last run, the one
where we did the little arcy-sparky thing was quite the tire ignition
sequence! Surely, someone got that on camera from the front or a
side-view shot???? I'd really prefer photos from this race, as it has
the car be-stickered with my battery sponsor's logo 'Hawker
AeroBatteries' and it would be great for them.
Hopefully, someone who missed my last request will remember they have a
few shots of the car for me :-)
See Ya....John Wayland
--- End Message ---
--- Begin Message ---
What's the optimal float voltage for new batteries? I've read where
float voltage should be set between 13.0 and 13.8/batt. since my pack
is new should I set the float voltage on my KW bc-20 at the high end of
that range? So far I've had it set at 13.4 right in the middle. My
pack is 8 12v batts
and then this morning my emeter said I had a fully charged pack which I
believed and expected having charged overnight, but the SG of all cells
was in the 1.225 -1.250 range?!! What could explain that? My charger
was running, had not tripped a breaker or the GFI. I have it set to
pull 10amps, and float voltage was set at 107. the emeter voltage is
set to 106. The current draw was less than 2amps.
I decided to reset the bc-20 following the current/voltage setting
instructions I turned the voltage to max and set the current to draw
10amps now 6 hours later the current draw is down to 3amps and the
voltage reading has been 124 volts and gassing slightly for the last 2
hours. The SG ranges from 1.280- 1.3 across the 48 cells. I figured
it's fully charged and turned down the voltage to 110 (up from 107).
Good? Bad?
Now it occurs to me that I've been assuming that "float voltage" as
pertains to the charger-manual is the same as "finish voltage" that
e-meter manual talks about. Is that a correct assumption?
comments appreciated, answers greatly appreciated!
thanks,
dave
96v '72 Honda-600
GE motor, 1221B
--- End Message ---
--- Begin Message ---
Stefan T. Peters wrote:
> Then a single diode it will be. At $10, it can handle much more current
> then 4 together anyways.
This is a 60hz power rectifier diode; not a switching diode. It will have a
"slow" turn-off time somewhere in the 1-100 microsecond range. A "fast"
switching diode will have a turnoff time of something less than 100
nanosecond range.
When a diode is conducting (+1v or so at rated current) and you reverse the
voltage across it, there is a time delay (called the reverse recovery time)
during which it still conducts full current. In a controller, this means when
that when the transistor turns on, there will be a DEAD SHORT thru the
still-conducting freewheel diode and the transistor for the reverse recovery
time! So, if you use a slow diode, you have to turn the transistor on equally
slowly, to allow time for the diode to turn off.
This is practical; indeed, it's what the Curtis controllers do. However, the
transistor and diode are dissipating a lot of power during this reverse
recovery time. Thus, it lowers the efficiency of the controller, and makes
the diode and transistor run hotter.
You can ignore reverse recovery time at 60 Hz. At 1 KHz it is beginning to
become troublesome with "slow" diodes. At 10 KHz and above, you must use a
"fast" diode or your switching losses will exceed your conduction losses.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Eric Poulsen wrote:
>> To be eligible for the tax credit, a vehicle must meet the following
>> requirements [snip]
>> * It has never been used as a nonelectric vehicle.
Dave wrote:
> So where does that leave coversions?
Out in the cold. Of course, the lobbyists and bureaucrats that wrote the rules
didn't intend that there be any conversions.
However, you can still play by their rules and "win" the tax credit. I've done
this three times. You need to re-title your EV as a "new vehicle". Thus, it
has never been used as a non-electric vehicle, and you are the first owner.
You will have to get a copy of your state's rules for titling a vehicle. They
aren't too bad for an individual; the assumption is that someone is building
a one-of-a-kind dune buggy, hot rod, antique reproduction, or other unusual
car for hobby use. The states where I've done this (NY, MI, and MN) only
required the normal equipment needed on any car; lights, horn, wipers, safety
glass, etc. No crash testing, air bags, emissions controls, or other
federally mandated equipment that would apply to a manufacturer.
Build your vehicle to meet your state's requirement. Then, you take it
somewhere and have it inspected for compliance. If it passes, you get your
title!
As a bonus, you get to pick the vehicle's make and model. My scratch-built EV
was titled as a "1978 Microvan". My 1980 Renault LeCar was titled as a
"Lectric Leopard" by U.S. Electricar. And my ComutaVan became a "1992
Assembled Electric".
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Hey Ken
I'm not sure if this would help, but what if you rotated the CE plate so that
the mount holes were at the 8 and 10 spots. The terminal position would rotate
also so you'd have to look at that. Just a thought I had on your mounting
issue, it would be real easy to rotate it 180 to more orientate the holes to
the existing mount area. The motor would run the same.
Cya
Jim Husted
Hi-Torque Electric
Ken Albright <[EMAIL PROTECTED]> wrote:
I just got the motor attached to the transaxle and stuffed into the '86 VW
Scirocco I'm converting (Hooray!). I'm reusing the three mounts that attach to
the tranny. For the motor end I'm still scratching my head.
The brush end of the motor has two 3/8" holes that look like they could be used
to attach a mount similar to the EA mount for the 8" motor. However, due to the
orientation, reusing the ICE motor mount location may cause sheer stress on the
bolts/holes. That is to say, when looking at the brush end of the motor, the
holes are at 2 and 4 o'clock and the existing mount location on the body is
over the 9 o'clock position. Anyone know how strong these holes and the end
plate are and how much stress would be placed on them?
Alternatively, is anyone making an end mount for the 9" motor?
I have the big belly band strap as supplied by KTA which I may end up using by
welding a connection between it and the ICE motor mount. However, that seems
like an inelegant solution.
Thanks
Ken
---------------------------------
Yahoo! Photos
Got holiday prints? See all the ways to get quality prints in your hands ASAP.
---------------------------------
Yahoo! Photos
Got holiday prints? See all the ways to get quality prints in your hands ASAP.
--- End Message ---
--- Begin Message ---
Hi Ken.
The backplate of the 9" motor has three lands or depressions that are 3/8"
deep. You could cut a 3/8" thick aluminum spacer to the same diameter of the
motor and cut out for the raised areas of the motor backplate. I think you have
to cut a center hole and three wedges out of the spacer plate. When you fit the
spacer on the back plate, the entire back of the motor is flush.
Bolt the spacer to whatever you are running up to the original motor mount.
The 3/8" spacer plate will be sandwiched in there and transmits the load to the
plate running up to the mount. The 3/8" bolts running into the back of the
motor just secures it and don't feel any load. For a typical sidewinder, that
mount mostly stabilizes the transaxle.
You can do the whole thing on a wood cutting bandsaw. Cut the wedges out, run a
cut into the center, cut the hole and then run the blade back out. Radius the
edges so it fits in the backplate nice. Use 6061 aluminum though.
I hope that gives you some ideas.
Dana
-------------- Original message ----------------------
From: Ken Albright <[EMAIL PROTECTED]>
> I just got the motor attached to the transaxle and stuffed into the '86 VW
> Scirocco I'm converting (Hooray!). I'm reusing the three mounts that attach
> to
> the tranny. For the motor end I'm still scratching my head.
>
> The brush end of the motor has two 3/8" holes that look like they could be
> used to attach a mount similar to the EA mount for the 8" motor. However,
> due
> to the orientation, reusing the ICE motor mount location may cause sheer
> stress
> on the bolts/holes. That is to say, when looking at the brush end of the
> motor,
> the holes are at 2 and 4 o'clock and the existing mount location on the body
> is
> over the 9 o'clock position. Anyone know how strong these holes and the end
> plate are and how much stress would be placed on them?
>
> Alternatively, is anyone making an end mount for the 9" motor?
>
> I have the big belly band strap as supplied by KTA which I may end up
> using
> by welding a connection between it and the ICE motor mount. However, that
> seems
> like an inelegant solution.
>
> Thanks
>
> Ken
>
>
>
> ---------------------------------
> Yahoo! Photos
> Got holiday prints? See all the ways to get quality prints in your hands
> ASAP.
>
--- End Message ---
--- Begin Message ---
At 12:28 PM 8/01/06 -0800, John G. Lussmyer wrote:
One thing I've noticed is that the EMeter current reading is about 15-20%
higher than my Analog ammeter I have on the charger shows. (Analog meter
was showing 21A, EMeter was 24.4A). Checking mv across the Ammeter shunt
with my Fluke meter, showed the Ammeter was quite correct.
Checking mv across the 500A shunt for the Emeter gave some odd readings.
Across the 2 big bolts for the power lines, it was 2.0mv (which is correct).
Across the 2 small sense line bolts I was getting 2.4mv.
Hi John - and all
(puts instrument technician hat on)
Sounds like one of:
1) dissimilar metals generating "extra" millivolts by thermocouple action
(most likely),
2) the shunt is designed to be used with a meter that 'burdens' the shunt
to a corrected reading, and the E-meter isn't burdening it (and dissimilar
metals makes your Fluke reading unreliable) but on a 500A shunt that would
be unlikely to be noticable (this shows up on low-amp shunts).
or
3) another connection on a sense wire causing extraneous signals (or a
combination of 1 & 3)
I'd disassemble the sense wires and wire-brush or emery (sand paper) clean
the surfaces, crimp or solder new terminals onto the sense wires and make a
nice clean corrosion-free connection to the shunt blocks, then see if the
problem has gone away. Make sure the sense wires are the only wires on
their bolts (yes, it does make a handy connection point for the voltmeter,
if need be drill and tap another hole in the block).
I'll take my instrument technician hat off again now.
Regards
James
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--- Begin Message ---
Checking mv across the 500A shunt for the Emeter gave some odd readings.
Across the 2 big bolts for the power lines, it was 2.0mv (which is
correct).
1) dissimilar metals generating "extra" millivolts by thermocouple
action (most likely),
There is another possibility: John is using this shunt in a Sparrow
powered by flooded NiCDs. I have noticed in my Elec-trak that my dual
shunts do show a slight charge all the time (.1a rate) and I think this
is because the KaOH around the batteries is reacting to the shunt. Clean
the connections, reconnect goes away for about 2 weeks. Copper and KaOH
don't seem to like each other much at all.
Question: Is it possible to get a nickel plated shunt? Or for John
perhaps he can put his shunt somewhere else out of the battery
vent-flow. Maybe in the tail by the controller or something. I'm
planning on moving my shunt to the Elec-trak's front compartment where I
have a pair of AGM batteries for the 24 volt loads.
Chris
2) the shunt is designed to be used with a meter that 'burdens' the
shunt to a corrected reading, and the E-meter isn't burdening it (and
dissimilar metals makes your Fluke reading unreliable) but on a 500A
shunt that would be unlikely to be noticable (this shows up on low-amp
shunts).
or
3) another connection on a sense wire causing extraneous signals (or a
combination of 1 & 3)
I'd disassemble the sense wires and wire-brush or emery (sand paper)
clean the surfaces, crimp or solder new terminals onto the sense wires
and make a nice clean corrosion-free connection to the shunt blocks,
then see if the problem has gone away. Make sure the sense wires are the
only wires on their bolts (yes, it does make a handy connection point
for the voltmeter, if need be drill and tap another hole in the block).
I'll take my instrument technician hat off again now.
Regards
James
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--- Begin Message ---
Lee Hart <[EMAIL PROTECTED]> wrote:
As a bonus, you get to pick the vehicle's make and model. My scratch-built EV
was titled as a "1978 Microvan". My 1980 Renault LeCar was titled as a
"Lectric Leopard" by U.S. Electricar. And my ComutaVan became a "1992
Assembled Electric".
--
Lee,
How does this effect insurance and, should i ever want to, resale?
---------------------------------
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--- End Message ---
--- Begin Message ---
That's about all you can get from 72 volts - it can get to 55 maybe but the
amperage goes way up, so you lose range.
Joseph H. Strubhar
E-Mail: [EMAIL PROTECTED]
Web: www.gremcoinc.com
----- Original Message -----
From: "Bill & Nancy" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, January 08, 2006 11:39 AM
Subject: Re: Fw: Geo Metro EV on a budget
> I'm running 72 volts, 40mph in 2nd and 45 mph in 3rd @100 amps.
> Bill
>
> jmygann wrote:
> > How fast can you go @ 100 amps ? How many volts ?
> >
> > --- In [EMAIL PROTECTED], Bill & Nancy <[EMAIL PROTECTED]> wrote:
> >
> >>1 hr rating @ 200 amps. I hadn't even considered the controller
> >
> > specs.
> >
> >>It is best for pack longevity to keep running amps below 100? Just
> >>learning as much as I can about driving the vw and the most efficiant
> >>operating range.
> >
> >
> >
> >
> >
> >
>
>
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
This is a 60hz power rectifier diode; not a switching diode. It will have a
"slow" turn-off time somewhere in the 1-100 microsecond range. A "fast"
switching diode will have a turnoff time of something less than 100
nanosecond range.
I was wondering about that. They have a "fast recovery" and a "very fast
recovery" version of it. The MOSFET package specifies a "time to final
Rds" of 15uS given the recommended 1uS rise time on the gate. Ruttonsha
doesn't seem to list actual recovery times of their power diodes, so I'm
left guessing for now. If I smoke the MOSFETs, I'll move up to the
faster one.
When a diode is conducting (+1v or so at rated current) and you reverse the
voltage across it, there is a time delay (called the reverse recovery time)
during which it still conducts full current. In a controller, this means when
that when the transistor turns on, there will be a DEAD SHORT thru the
still-conducting freewheel diode and the transistor for the reverse recovery
time! So, if you use a slow diode, you have to turn the transistor on equally
slowly, to allow time for the diode to turn off.
That would be a battery short with this setup, so I'll want to avoid
that. I can raise the rise time on the gate of the MOSFET, but the power
rating will go down.
I wonder how much I can get away with? What would be some symptoms of a
to-fast MOSFET turn on time for a particular diode (besides the smoke
thing)?
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
Cory Cross wrote:
When the controller turns on, the current ramps up (because current
cannot change instantly in an inductor -- the wiring). When it turns
off, the current keeps coming, boosting up the voltage on the
capacitors, which is then drawn down next time the controller turns on.
You have the right general idea, but the details are wrong.
I was just trying to describe the battery portion of the problem
here, and the motor problem later. I should have explicitly said that is
a very small effect.
...
It's the BATTERY ripple current that we are more worried about. In a PWM buck
converter with no input capacitors, the battery current iz ZERO during the
controller "off" time. During the controller "on" time, it follows the motor
current; 90 to 110 amps for the above example. So at a 50% duty cycle, the
battery current is 0,0,90,110 amps; the average is 50 amps battery current.
The controller is converting full pack voltage at 50 amps average into half
pack voltage at 100 amps average for the motor.
If we want lots of torque at low duty cycles, the power source may
need to provide, say, 50C in bursts. The only thing I can see to smooth
this (in a standard "buck" controller) is adding more inductance or
capacitance before the controller or boosting the frequency, right?
Since inductance is hard on the controller, and we were talking about
lower frequencies, the only solution I saw was more capacitance (as
stated below).
Is the standard capacitance and frequency on Curtis or Alltrax
controllers enough?
I suppose you could use enough capacitance to solve the problem on the
battery end, but you'll need to add more inductance or resistance to the
motor. Being that more resistance is bad, you'll have to add quite an
inductor that can take full motor current -- probably will be larger
than the motor itself!
These are separate problems, as described above. If you want to add motor
inductance, the easiest way is to use a motor with more iron in its outer
casing; that's what fork lift motors do. The motor is heavier, but not as
heavy as adding a separate inductor.
I guessed wrong on the inductor size, apparently.
In Roger's case, they may not be completely seperated. If, at 300Hz,
his motor current is dropping significantly, his current peak must be
higher, which the battery must provide. This may or may not be significant.
Cory Cross
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--- Begin Message ---
Jim Husted wrote:
>mod'ed it to go into one of those 15" Prestolite motors
Hmmm... Would that be 15" long or 15" in diameter?
--- End Message ---
--- Begin Message ---
Hey Ryan
That was length. One of the pump motor type that come up on Ebay quiet
often. Used by the daily guys.
Cya
Jim Husted
Hi-Torque Electric
Ryan Stotts <[EMAIL PROTECTED]> wrote:
Jim Husted wrote:
>mod'ed it to go into one of those 15" Prestolite motors
Hmmm... Would that be 15" long or 15" in diameter?
---------------------------------
Yahoo! Photos
Ring in the New Year with Photo Calendars. Add photos, events, holidays,
whatever.
--- End Message ---
--- Begin Message ---
Dear Dave,
I was expecting some of the real battery gurus to
have answered you by now, so here's the deal:
a) Float voltage is generally around 2.1 volts per
cell. Looks like you have 12 volters, so that's 6
cells, or 12.6V. Finish voltage is a bit higher, and
truly depends on your manufacturer. And, if you've
followed my thread lately, that's a real sore spot
with me, so I'm going to pass on that.
b) Your e-meter will re-set based on the charged
parameters. That means that both a voltage, _and_ a
finish current have to be met. My hunch is that
either you have not set your charged parameters
correctly, or, the charger never met those charged
parameters. The fact that you said it re-set itself,
indicates that it is the former, not the latter.
Sincerely,
--- Dave <[EMAIL PROTECTED]> wrote:
>
> What's the optimal float voltage for new batteries?
> I've read where
> float voltage should be set between 13.0 and
> 13.8/batt. since my pack
> is new should I set the float voltage on my KW bc-20
> at the high end of
> that range? So far I've had it set at 13.4 right in
> the middle. My
> pack is 8 12v batts
>
> and then this morning my emeter said I had a fully
> charged pack which I
> believed and expected having charged overnight, but
> the SG of all cells
> was in the 1.225 -1.250 range?!! What could explain
> that? My charger
> was running, had not tripped a breaker or the GFI.
> I have it set to
> pull 10amps, and float voltage was set at 107. the
> emeter voltage is
> set to 106. The current draw was less than 2amps.
>
> I decided to reset the bc-20 following the
> current/voltage setting
> instructions I turned the voltage to max and set the
> current to draw
> 10amps now 6 hours later the current draw is down
> to 3amps and the
> voltage reading has been 124 volts and gassing
> slightly for the last 2
> hours. The SG ranges from 1.280- 1.3 across the 48
> cells. I figured
> it's fully charged and turned down the voltage to
> 110 (up from 107).
> Good? Bad?
>
> Now it occurs to me that I've been assuming that
> "float voltage" as
> pertains to the charger-manual is the same as
> "finish voltage" that
> e-meter manual talks about. Is that a correct
> assumption?
>
> comments appreciated, answers greatly appreciated!
> thanks,
> dave
> 96v '72 Honda-600
> GE motor, 1221B
>
>
'92 Honda Civic sedan, 144V (video or DVD available)!
www.budget.net/~bbath/CivicWithACord.html
____
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'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering wheel?
Are you saving any gas for your kids?
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