EV digest 6515

Mon, 05 Mar 2007 19:57:38 -0800 

                            EV Digest 6515

Topics covered in this issue include:

  1) Re: My next EV project, or Paul goes Datsun
        by "Paul G." <[EMAIL PROTECTED]>
  2) Simple electronics component question
        by Dave Cover <[EMAIL PROTECTED]>
  3) Phoenix EAA EV EXPO 2007
        by DM3 <[EMAIL PROTECTED]>
  4) Re: wheel hub motor
        by James Massey <[EMAIL PROTECTED]>
  5) Re: wheel hub motor
        by "Peter VanDerWal" <[EMAIL PROTECTED]>
  6) RE: [Evtech] SCR's last orders
        by Cor van de Water <[EMAIL PROTECTED]>
  7) RE: PIC help
        by Cor van de Water <[EMAIL PROTECTED]>
  8) Re: electric power newbie
        by "garyH" <[EMAIL PROTECTED]>
  9) Re: Processor Lockup Failsafe
        by Jack Murray <[EMAIL PROTECTED]>
 10) RE: Simple electronics component question
        by Cor van de Water <[EMAIL PROTECTED]>
 11) Re: wheel hub motor
        by Ian Hooper <[EMAIL PROTECTED]>
 12) Re: Motor mods
        by Jim Husted <[EMAIL PROTECTED]>
 13) RE: Prius OEM Tires
        by Cor van de Water <[EMAIL PROTECTED]>
 14) RE: Mick's answer to Lee Hart about BattEQ test
        by Cor van de Water <[EMAIL PROTECTED]>
--- Begin Message --- 
On Mar 5, 2007, at 8:46 AM, [EMAIL PROTECTED] wrote:
Sorry for the dumb question. I'm new here. I wasn't aware the Prius used 
special tires.  How do they differ from tires on other cars?
Different passenger car tires have different rolling resistance, even in the same size. Many new cars are equipped with tires designed for reduced rolling resistance from the factory as part of their effort to improve the Corporate Average Fuel Economy (CAFE.) Auto makers have to meet overall mileage targets or pay fines, this gives them the incentive to find creative ways to boost fuel mileage, even if only a little. Of course, the Prius sells on fuel mileage so Toyota chooses the tire extra carefully. They have used low rolling resistance (LLR) tires made by various manufactures (and available as replacements.) I will point out that the Prius specific Potenza is only a 30,000 mile tire (though mine lasted 40,000 miles with 3/32 tread left on my 2002 Prius.)
Its worth noting that LLR tires can be more important on an electric vehicle than most ICE vehicles. Generally, the gas engine is slightly more efficient at power levels above what is required to go freeway speeds. So the effect of lowering power requirements is partly countered by a reduction in engine efficiency. Since most electric cars have a wide range near peak motor efficiency the full effect of reduced drag is seen in power consumption (range.) 

Paul "neon" G.

--- End Message ---
--- Begin Message --- 
I read an article about a simple circuit to drive LEDs and am thinking of using 
it for some
running lights in my car. The circuit specifies LM317L as a constant current 
source. Perfect
project for my skill level. But I kept running into LM317T modules. Is there a 
difference between
an LM317L and an LM317T?

Thanks

Dave Cover

--- End Message ---
--- Begin Message --- 
Just an FYI, 
The Phoenix EAA will have a display set up at one of the local Auto swap
meets to show our EVs and supply info to the general public.  It will be
at Glendale Community College and in conjunction with a popular auto swap
meet.  We hope this will attract people that would not normally be exposed
to our cause and give them an opportunity see and discuss Electric
Vehicles.  It will be held on March 17 and 18 and we will have several EVs
on display - see attached link to the flyer we are circulating.  Everyone
is welcome! 

http://www.phoenixeaa.com/documents/ev_expo_07.pdf

We hope for it to be successful and the first of an annual EVent.

Thanks,
Mario

--- End Message ---
--- Begin Message --- 
At 03:18 PM 5/03/07 -0800, Karsten wrote:
Hello my name is Karsten and I am researching building my first electric vehicle. I am interested in using an electric in wheel motor. I wanted to build an offroad (but street legal) vehicle to start with, because I know my range and speed will be limited by my budget. I was thinking of taking an old ford bronco rolling chassis and converting it to electric. The ford Bronco with a fiberglass body is a pretty light vehicle if I could take out the transfer case, transmission, etc... Having 4 independent electric motors as wheels would be incredible for 4wdriving. Are there any other manufacturers for in wheel electric motors? Are there any other options that I can convert to make an electric wheel? Any info regarding electric motors in wheels would be greatly appreciated. Thank You. 

G'day Karsten
Unfortunately wheel motors for full-size vehicles seem to only be available at a sort-of-experimental stage and about $20k each, $80k for 4WD.
Anything you could convert to be a psudo-hub motor will be heavy (forklift wheel-motors, etc) making your unsprung mass horrible, and front-wheel mounting probably impossible.
Sorry, but "on a budget" means you are keeping the diffs at least. Have you looked for ideas at 1) ProEV where they have done an imprezza conversion with AC drive systems and just the diffs (no gearbox/es) and 2) IIRC it was Wilde EVolutions who fid a landrover conversion.
If you are seriously on a buget, then a small 2WD sedan/wagon/pickup is probably cheapest. Someone elses' conversion that needs batteries can be picked up in many areas of the USA for less than the price of the components, if you are prepared to wait and search. A big old electric forklift can be a cheap source for a motor and contactors, possibly a controller for a low-voltage conversion. 

Hope this helps

Regards

[Technik] James

--- End Message ---
--- Begin Message --- 
Are there any other manufacturers than who?  For the hub motor that is.

The only one I'm aware of for full size EVs is the NGM motor and they co$t
big buck$ for each one.  They aren't all that powerful, relatively low
torque.
Using four of them is definitely NOT a budget conversion.  In fact the
cost of just one is about twice what most people spend on their entire
conversion.
Well, there was the company that made the motors they used in the hybrid
Humvee, but they cost even more than the NGM motors, and I've never seen
they advertised as available.

Also, have you actually weighed a bronco with a fiberglass body?  Unless
you custom build the body by hand, I don't think you're going to save more
than one or two hundred pounds at most.
Plus they are expensive, even if you build them yourself.

Doesn't sound like much of a budget vehicle.

You might want to rethink the basic concept.  If you want to build an off
road EV, great.  But if you want to do it on a budget, I'd consider
converting a quad ATV.

> Hello my name is Karsten and I am researching building my first
> electric vehicle. I am interested in using an electric in wheel motor.
> I wanted to build an offroad (but street legal) vehicle to start with,
> because I know my range and speed will be limited by my budget. I was
> thinking of taking an old ford bronco rolling chassis and converting it
> to electric. The ford Bronco with a fiberglass body is a pretty light
> vehicle if I could take out the transfer case, transmission, etc...
> Having 4 independent electric motors as wheels would be incredible for
> 4wdriving. Are there any other manufacturers for in wheel electric
> motors? Are there any other options that I can convert to make an
> electric wheel? Any info regarding electric motors in wheels would be
> greatly appreciated. Thank You.
>
>


-- 
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 --- 
Chris,

<Space> is an illegal character in an email address. I guess it is an
underscore "_"?


Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
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
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb

-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED]
Sent: Monday, March 05, 2007 3:57 PM
To: ev@listproc.sjsu.edu
Cc: [EMAIL PROTECTED]
Subject: [Evtech] SCR's last orders

Just to give a closing update about the SCR's I mentioned a short while ago
which were going cheap.
 
I have finally heard back from the seller, who says he can let me have any
number for £4 each, he has over 100.
 
The specs are in the last of my blog messages, here
_http://journals.aol.co.uk/fixitsan/electric-car-building/_
(http://journals.aol.co.uk/fixitsan/electric-car-building/)  
 
I appreciate I didn't contact anyone who wrote back to me about this, but I
needed to wait to be told the final unit cost.
 
I may be buying a few more myself, but should anyone want any for
themselves the seller has allowed me to disclose his details which are as
follows His name is Dave, and his email address is [EMAIL PROTECTED]
(mailto:[EMAIL PROTECTED])
(reimann<space>AThotmailDOTcom)
 
He will sell them for £4 plus the actual postage cost, bear in mind the
weight of the bases/mounts,  I haven't asked him but he may be willing to
take the SCR capsules out of the mounts and ship them on their own to save
shipping costs.
 
Chris
 
   
_______________________________________________
Evtech mailing list
[EMAIL PROTECTED]
http://mailman.evtech.org/mailman/listinfo/evtech

--- End Message ---
--- Begin Message --- 
Usually if a pin has multiple functions, then is also has a configuratoin
register which needs to be written to tell which of the functions is enabled
(it may be that the pin by default has the program function enabled, so you
need to tell it to change it to the I/O function.
Sometimes a second config register needs to be written to tell if the I/O
pin acts as input or output.
 
Success,

Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
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
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of FRED JEANETTE MERTENS
Sent: Monday, March 05, 2007 3:12 PM
To: ev@listproc.sjsu.edu
Subject: Re: PIC help

brain what are you doing for a speedometer ?  are you mounting a display of
some sort ? I wanted to use a touch screen for my gt2 e   but have not found
anything that will work and be powered by dc voltage  . I wanted to display
speed / motor volts / motor amps and maybe rpm  or pack voltage . are you
using a pc ? 
  ----- Original Message -----
  From: brian baumel<mailto:[EMAIL PROTECTED]>
  To: ev@listproc.sjsu.edu<mailto:ev@listproc.sjsu.edu>
  Sent: Monday, March 05, 2007 10:09 AM
  Subject: PIC help


  greetings everyone,
  I am almost done with building a custom speedometer
  for my EV. I am have a small problem with it thought,
  one pin to be exact. I am using a PIC16F872 portA is
  all inputs, port B and C are directly coupled to some
  7447 display drivers(3 digits, 3 display drivers). my
  problem is in portB.3 this pin will just not toggle!!!
  I have tried 2 different PIC16F872 and a PIC16F876A
  none will toggle PORTB.3. 
  I have programmed it so that ports B and C blink, but
  that one pin just will not toggle on any occassion. am
  I forgetting to disable/enable something, like what is
  done to turn off the ADC on portA (ADCON1=7)??
  the data sheet says something about PORTB.3 is a I/O
  or a PGM...some type of medium voltage programming
  mode.
  some one please help. right now I'm using a bike
  speedometer and it sucks.

  thank you,

  Brian B.
  81' Bradley GTII



   
 
____________________________________________________________________________
________
  Food fight? Enjoy some healthy debate
  in the Yahoo! Answers Food & Drink Q&A.
 
http://answers.yahoo.com/dir/?link=list&sid=396545367<http://answers.yahoo.c
om/dir/?link=list&sid=396545367>

--- End Message ---
--- Begin Message --- 
Hi Peter,
Thanks for the explanation.I have a basic understanding but it still needs to be hammered home. 
<Since your motor has separate shunt field terminals, I'm going to assume
it has separate terminals for both the series field and the armature
(connected to the brushes).
On the terminal block are 4 terninals,2 large and 2 small,one of the small terminals is unused,the other small terminal goes to the negative side of the brush holder (8 brushes).The positive terminal connects via a large wire to the positive side of the brush holder.The negative terminal has a large wire which disappears into the field windings.Coming off of the field windings are 2 medium sized wires which go to the negative side of the brush holder.Of note is what appears to be a smaller winding which seems to snake around the field coils,but hard to tell without taking it all apart.I don't know where the other end of the generator field connects, somewhere internally.I'm not sure if this is what you envisioned. The terminals are labeled B,which I believe is the positive because it goes to the insulated side of brush holder, E and A which is the small terminal. What I'm not sure about is if there enough external terminals to run as a shunt motor or will I have to bring some wires out of the motor. thanks......gary
----- Original Message ----- From: "Peter VanDerWal" <[EMAIL PROTECTED]> 
To: <ev@listproc.sjsu.edu>
Sent: Monday, March 05, 2007 3:52 PM
Subject: Re: electric power newbie



Hmm, ok.  I'll try to keep this simple.

Let's start with a little physics lesson/refresher.

If you pass a wire through a magnetic field in such a way that it cuts
across the lines of force, you will induce a current in the wire.

Likewise if you have the same setup, but don't move the wire, and you pass
a current through the wire, it will generate a magnetic field which will
push against the existing field and try to move the wire.

The first principle is what generators are based on, the second is what
motors are based on.

The important thing to keep in mind is that basically all motors are
generators, and vice versa.
The REALLY important thing to keep in mind is that basically every
motor/generator performs BOTH fuctions AT THE SAME TIME.

So while your motor is motoring, it is also generating electricity
internally.  This generated voltage apposses the applied voltage and is
what stops the motor from continuously accelerating.  This is normally
called a "Back ElectroMotive Force" or BEMF.
The BEMF appears from the outside to be a variable resistance that
increases as the RPMs go up, and it limits how much current the motor will
draw.
Basically the applied voltage minus the BEMF equals the voltage the motor
"sees" internally.  Divide this voltage by the internal resistance of the
motor and you can determine how much current the motor will draw.

The amount of BEMF produced depends on the RPM of the motor and the
strength of the magnetic field surrounding the spinning armature.

Anyway, the important thing to remember is that the BEMF determines the
speed to motor spins at.  Reduce the BEMF and the motor draws more current
(larger difference between applied Voltage and BEMF), and because of the
extra current the motor has more torque and it speeds up.  Which increases
BEMF and at some point (normally) ballances out and the motor stops
accelerating.

Oh well, so much for keeping it simple.

Ok now let's talk about shunt motors.  These work kind of backwards to
what most people would expect, but if you understand the above, you'll
understand why they work like they do.

Since your motor has separate shunt field terminals, I'm going to assume
it has separate terminals for both the series field and the armature
(connected to the brushes).

Power up the shunt field FIRST with 24V (I'm guessing that's the right
voltage for the shunt).  Then apply voltage to the armature (brushes).
Now here's the cool thing, if you apply a load to the motor it will try to
spin at just about the same RPM as it does without a load.  This is
because with a shunt motor the BEMF is independent of the load and/or
applied current.  It depends solely on the RPM.  It will slow down
slightly under load, enough to draw more current and ballance the input
power to the output power.

Now to adjust the speed of the motor you reduce the voltage across the
field, this will cause the motor to speed UP.  Yup, that's right, reduce
the voltage on the field and the motor goes FASTER.  That's because
reducing the field voltage reduces the magnetic field which reduces the
BEMF so the motor draws more current and spins faster to build the BEMF
back up and ballance the equation.

So basically, as long as the speed the motor turns at, with full field
voltage, is slow enough for you, then you don't need to adjust the
armature voltage (it can be full pack voltage).  This means you only have
to control the armature voltage/current and this is MUCH lower current
than the armature draws.  You can probably even control it using a high
power rheostat (like a big wire wound variable resistor).
However, electric bike controllers are dirt cheap these days and one of
those would probably work to control the field.  Just make sure you turn
it on and then go to FULL voltage (what would normally be MAX speed on a
bicycle) before you turn on the armature, in order to keep the motor at
minimum RPM.

So all you'd need is the low power controller for the field and a
contactor for the armature.

Using it as a shunt motor is probably your best option since you won't
over spin the motor if it starts to cavitate.  This is because it will
want to spin at about the same RPM without a load as it was under load.
It will spin a bit faster without a load, but it WON'T try for infinity
like a series wound motor.

Oh yeah, you can also reverse it easier as a shunt motor because you can
simply reverse the armture current or the field current.  Even though it's
easier to reverse the field, I'd probably do the armature to make sure you
don't have the armature powered up with no field current.  If you do this
(no field current) it will try to operate similar to a series wound motor
and will shoot for infinity and beyond.  At the very least it will draw
HUGE ammounts of current through the armature.  With little to no BEMF the
current is only limited by the internal resistance of the motor (way less
than 1 ohm)
So don't EVER have power on the armature without current running through
the field.  You will probably need to add some safeguards on the
controller to make sure that it always goes to FULL voltage BEFORE you
turn on the armature.

That's not the clearest explanation I've seen, but hopefully you
understood it.

Cheers, Pete.


Thank you Peter for your reply you have made things a lot clearer.
<So running the motor at under it's rated current is no problem,
running at OVER it's rated current can get you in trouble.>
I have tested the motor with 12V and then 24V being aware of its desire to 
self destruct.I also had an ammeter connected to it which went to 110A
when
I put load on the motor.Freewheeling it was 60A.So I'm figuring current is 
related to load which is almost constant for my application.(no hills to
climb).
That is very interesting running it as a shunt motor.There is a smaller
wire
coming out of the field coils for generator field excitement.Could you
explain how I would rewire for shunt use.
Cavitation is a concern for me because it would cause the motor to speed
up
causing more cavitation etc.
Name Plate Details:
Westinghouse Elec and Manufacturing Co. (I guess that kinda dates
it.1950's
I figure)
Mfr.serial no. AF44-945490
Type P-1
"for use with 24V systems"
also,drawing no.,and acceptance no.
thanks..........gary
----- Original Message -----
From: "Peter VanDerWal" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Monday, March 05, 2007 7:13 AM
Subject: Re: electric power newbie





The motor does have a intake for
external fan but being a starter generator I am a little worried that
continuous use as a motor may not be something it is capable of doing.


They are generally under continuous use when operating as a generator.
The difference between a motor and a generator is simply which direction
the energy is going.

However, from what I've read Air Craft starter/generators are typically
not very efficient.  It's going to be turning a lot of your energy into
heat, so you need to get rid of the heat.

The guys that used to race E-boats would often dunk the whole motor in
the
water after a race.  You might want to keep that in mind as a method to
quickly cool down the motor if you do over heat it.

I

am
not well versed on controllers but my understanding is that they switch
off
and on to reduce voltage to motor as required.What happens to a motor
that
is too powerful for its application and is always being used at say 60%
load. If this were a 100V motor would it be continuously running on 60V
and
would this damage the motor ...Gary


Nope.  Actually you can probably run your motor at MORE than the name
plate rating.  The voltage rating on a motor is just one point on the
spectrum of voltages & currents that the motor can operate at.
Often motor manufacturers will take the EXACT same motor and put two
different rated voltages on it for two different customers.

There are basically two things that can damage a motor: getting it too
hot, and spinning too fast.

The current through a motor causes heat.  As long as you can get rid of
the heat, no problem.  The higher the current through the motor, the
more
heat it generates.  At some point the motor gets hotter than you can
cool
it off.  When this happens the motor starts to get hotter, and hotter.
Once it gets hot enough the insulation starts to melt/fry and then you
get
shorts in the motor, and then the windings, etc. start to melt.

Now here's the bad news, the ammount of heat generated goes up as the
SQUARE of the current.  Double the current and you get four times as
much
heat.  So running the motor at under it's rated current is no problem,
running at OVER it's rated current can get you in trouble.  You can
generally do if for a short time (The motor has a lot of mass and takes
a
while to heat up), but the higher the current, the less time you can do
this.
It's best to play it safe and stay under the rated current.

Now for the RPM.  I'm not sure what kind of RPM these motors can take,
perhaps Lee will step in and give his opinion.  But at a guess I'd say
it's probably 5,000 to 6,000 RPM.
Keep it under that, and you have no problem.  Let it go over that and
the
motor goes into self-disassembly mode.  Not pretty.  Motors aren't very
smart and I haven't seen one yet that can take itself apart in a manner
where it's easy to put it back together.

I believe your motor operates as a series wound motor in the starter
mode,
and a shunt wound motor/generator in the generator mode.

If this is the case, then I'd run your motor as a shunt wound motor.
It's
a lot easier to control (and the controllers are cheaper) plus you don't
have to worry about over-revving it so much.  In fact you could probably
get away with using a cheap E-bike controller for controlling the field
voltage.

Can you post the manufacturer and part number from the motor?  It would
make it a lot easier to suggest a method for controlling the motor.
Post
everything that's on the name plate.

*******************
Series wound motors
*******************
For most motors the RPM is related to the voltage.  Double the voltage
and
you double the RPM.  Series wound motors are a little different.  The
voltage/RPM relationship is only true for a given load.  Reduce (or
remove) the load and the RPMs go up.   Power the motor up with it's
rated
voltage and no load and it will happily try to spin up to near infinite
RPMs.  Unfortunately, long before it gets to infinity, parts of the
motor
will decide to relocate.


The moral here is not to power the motor up without a load unless you
are
using very low voltage.  With a low enough voltage the friction in the
motor is enough of a load to keep it from overspinning.
Of course the problem is: how low is "low" voltage.  In your case I'd
probably start with 6 volts and see if it sounds like the motor is going
to spin too fast.  With only 6 volts it will take the motor a bit to get
up to speed.
If it turns REALLY slowly, then you can probably get away with 12V.
If it starts to pick up speed and sounds like it's going to keep picking
up speed, then disconnect and try a lower voltage.

The above is just for testing.  Once you have a prop connected, you
shouldn't have to worry about it as long as the prop is in the water.
Hmm, unless you start to cavitate.  If that happens, and your voltage is
high enough, you might get into over-rev territory.  I can't say for
sure
since I'm not even close to playing a boating expert on TV.


----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Sunday, March 04, 2007 9:38 AM
Subject: Re: electric power newbie



[EMAIL PROTECTED] wrote:

I'm starting to build a small electric propulsion system . I
have a 24V Westinghouse aircraft starter-generator which were sold
by Princess Auto of Winnipeg at one time. It is 8 pole series
wound, around 3 Kw I believe, so should be ample power for my
application. I haven't been able to get any specs on this machine
so I'm not sure if its rated for continuous use or not. Does
anyone have any info for this motor?


You'll have to provide more information for us to be able to tell what
you
have. What does the nameplate on it say? What is its size and weight?

3kw is only about 3 horsepower; that's not much. OK for a golf cart or
small motorcycle, but not a car.

Most of these units are designed for continuous duty at high rpm, with
a
very strong airflow for cooling.


I'm also not sure if drive will slow the motor down to the 900 or so
RPM it would like to run at. Maybe the controller will take care of
this.


A controller can make it run slower, but you also decrease power. If
it
produces 3kw at full speed, it will only produce 1.5kw at half speed,
etc.


Is it possible to reverse this motor?


Yes, but they usually require some disassembly and internal wiring
changes.

--
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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--- End Message ---
--- Begin Message --- well the RPM is displayed to the driver on the tach, they can decide to heed it or ignore it. If the motor explodes that might be more trouble than an unannounced killing of the power. 
Jack

Cor van de Water wrote:

Note that RPM monitoring is good to avoid over-revving and 'sploding a
motor.
You could make a difference between the official redline, where you'd want
to
turn a warning on for the driver (Idiot engine light or so) and possibly
kill
throttle input, and a (higher) level where you drop contactors, killing the
entire car's HV power.

As long as brakes and possible regen braking are not affected by this safety
then you are OK, but your solution of unannounced dropping contactor can
lead to sudden loss of control in a quick long descent, if any of the
systems
depends on the presence of HV.
Just a thought,

Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
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
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Jack Murray
Sent: Sunday, March 04, 2007 10:06 AM
To: ev@listproc.sjsu.edu
Subject: Re: Processor Lockup Failsafe

I use MSP430 processors, and they (many most? others) have what is called
watchdog timer.  It can be configured to reboot the processor if the
watchdog doesn't get reset periodically by the software.
Of course if the processor itself burns up it won't be rebooting, but you
can do the circuit such that passive components will have the normal state
OFF, so the MPU must run to turn them on.  There are also external
supervisor chips you can use to do monitoring and turn on/off things when
fail conditions occur.  I find it easier to just us another MPU.

This is what I have made for a "pre-charge" controller, before it turns on
the main contactor it turns on the pre-charge and makes sure the current
stops flowing before allowing the main to turn on.  It also monitors the RPM
and will shut off the main contactor if it goes too high. And checks the
throttle and turns off the contactor if the throttle is closed and battery
current is still flowing.
And it monitors the current drain to give a fuel-gauge output.

Jack

Bill Dennis wrote:
If you're using a microprocessor to control charging, what's a good way to have the system fail to a safe state, should the processor freeze up--for example, turn off the charger. One possibility that came to mind was some type of circuit or chip that expects its input to be flip-flopped every few seconds, and if it isn't, opens a relay. Is there a simple circuit or chip that already does this? Or is there a better way? 

Thanks.

Bill Dennis

--- End Message ---
--- Begin Message --- 
The -T has a TO-220 package and delivers max 1.5A
the -L has a TO-92 or SO-8 package and delivers max 0.1A


Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
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
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Dave Cover
Sent: Monday, March 05, 2007 5:42 PM
To: ev@listproc.sjsu.edu
Subject: Simple electronics component question

I read an article about a simple circuit to drive LEDs and am thinking of
using it for some running lights in my car. The circuit specifies LM317L as
a constant current source. Perfect project for my skill level. But I kept
running into LM317T modules. Is there a difference between an LM317L and an
LM317T?

Thanks

Dave Cover

--- End Message ---
--- Begin Message --- Yeah I looked into doing the wheel hub motor thing once. It does seem like the "holy grail" of electric drive, but I have to agree with James - it's not really feasible right now. The motors have to be so light yet powerful (and you need four of them!) = expensive. The next best thing is to have individual motors driving the inside end of each CV joint, less engineering involved and motor weight isn't such a concern. That said, it's only possible on vehicles with CV joints (independent suspension)..
For something like a Bronco, I'd go with a Warp11 in place of the engine: http://www.go-ev.com/motors-warp.html 

-Ian

On 06/03/2007, at 11:17 AM, James Massey wrote:


At 03:18 PM 5/03/07 -0800, Karsten wrote:
Hello my name is Karsten and I am researching building my first electric vehicle. I am interested in using an electric in wheel motor. I wanted to build an offroad (but street legal) vehicle to start with, because I know my range and speed will be limited by my budget. I was thinking of taking an old ford bronco rolling chassis and converting it to electric. The ford Bronco with a fiberglass body is a pretty light vehicle if I could take out the transfer case, transmission, etc... Having 4 independent electric motors as wheels would be incredible for 4wdriving. Are there any other manufacturers for in wheel electric motors? Are there any other options that I can convert to make an electric wheel? Any info regarding electric motors in wheels would be greatly appreciated. Thank You. 

G'day Karsten
Unfortunately wheel motors for full-size vehicles seem to only be available at a sort-of-experimental stage and about $20k each, $80k for 4WD.
Anything you could convert to be a psudo-hub motor will be heavy (forklift wheel-motors, etc) making your unsprung mass horrible, and front-wheel mounting probably impossible.
Sorry, but "on a budget" means you are keeping the diffs at least. Have you looked for ideas at 1) ProEV where they have done an imprezza conversion with AC drive systems and just the diffs (no gearbox/es) and 2) IIRC it was Wilde EVolutions who fid a landrover conversion.
If you are seriously on a buget, then a small 2WD sedan/wagon/ pickup is probably cheapest. Someone elses' conversion that needs batteries can be picked up in many areas of the USA for less than the price of the components, if you are prepared to wait and search. A big old electric forklift can be a cheap source for a motor and contactors, possibly a controller for a low-voltage conversion. 

Hope this helps

Regards

[Technik] James

--- End Message ---
--- Begin Message --- 
Hey Jeff, Mini, all
--- James Massey <[EMAIL PROTECTED]> wrote:

> G'day Jeff, Jim and All
> 
> At 09:01 AM 5/03/07 -0800, Jeff wrote:
> >Hi Jim,
> >   I had inquired of James if these were MKZ type
> >   motors.  Never got a reply.
> 
> Sorry Jeff, missed that message. MKZ-4003S motors.

I seem to have the opposite problem, he writes me but
doesn't wait for my reply 8^o

> >  The MKZ was a problem child design.  It was field
> swamped.  Way, way too 
> > much.  So the field coils tended to fry.  Too high
> I squared R.  The 
> > motor was really not too small for that lift
> truck.  Replacement design, 
> > MKN type did just fine.  MKN was same motor design
> as MKZ except a lot 
> > less effective field strength (turns) and lower I
> squared R.  Also has a 
> > 13 tooth gear in place of 16 (on MKZ) to
> compenstate for higher 
> > RPM.  Glad to hear he put field in S/P
> (series-parallel) from all in 
> > series.  That cuts amp-turns in half and I squared
> R (field heat) by 
> > factor of 4.  He probably has no need to bring out
> 4 field 
> > terminals.  Just leave in S/P.

You know I had a nice, easy to type, resonable
explaination leading to the fact the motor was known
to burn up field coils, BUT NOoooo you have to get all
technical and stuff, LMAO!

I used to do a lot of these MKZ's way back when.  They
were fine for a shop like mine, use them an hour a
day, but put them in a distribution outlet and they'd
cook them in weeks.  I can't remember which it was but
the MKZ were used in two different brands, Clarks and
Crowns, one burnt the fields much harder than the
other.  Now the MSU has the same armature but corser
wound fields and faired a lot better, but then tended
to burn the armature up over the fields.

Comparing the dual 50 to 60 lbs ea. Prestolites
against the older 200 to 300 lbs single drive Ottis,
GE's, and Allis Chalmers (that had been driving
forklift before them) is another reason I used
undersized.  Again as memory serves that was a good
sized sitdown forklift the MKZ's were used in?

Thanks for the info,  It's nice to here that someone
else knew there was an issue  with that motor and for
comfirmation that it wasn't my crappy rebuilds causing
the problem (I got that a few times with that motor
from customers, hehe).

> >   Also a thought on the brush cross connectors
> where you have clearance 
> > issues.  Why not bring out 4 "A" terminals?  Two
> A1's and two A2's.  

Rod Wilde did this on his 9" for Gone Postal.  He
didn't run them through the face but instead added two
more holes on the two remaining window supports.
It's a nice upgrade actually and one that a higher
percentage of people could do "in house" so to speak.

In the end James did it this way because the two
motors will be spinning different directions
requirering different advancements and he didn't want
to have to make two different lead sets.  Being the
windows are formed in the housing it'd been tough to
have left the leads in the housing.

The biggest downside is that there are more electrical
connections outside the motor.  

> I'll glue the spacer ring to the brush ring with
> epoxy adhesive on assembly 
> for extra strength - there are small cracks
> alongside each brush holder, on 
> the side of the holders away from the rivets, i.e.,
> right where the new 
> terminal holes are going!

It seems you've done a few Prestolite motors using
that MCP-164 base plate for the holders.  Might have
to throw a couple in the next box out after you get
done misering through the last of that Fusa Fab I sent
you.

> Will have the first motor finished tonight
> (hopefully, doing it out of 
> working hours). Second motor won't take so long as I
> don't need to figure 
> out what I'm doing and I'll have some parts already
> made.

I hear what your saying about working the bugs out and
the next one being easier.  Having finished just one
though there is that, Ohh crud, I'm only half done
kind of after taste when building dual motors 8^P
 
> Jim, you asked how much time. Not including the time
> lost making the cross 
> bars I'm up to about 8 hours so far, I guess the
> mods will be about 20 
> hours for the two motors. If I had top-hat
> insulators available I would 
> probably save 3 hours (by the time I've turned up 8
> of them).

You know that's not bad Mini-me.  I was just wondering
because I know how fast my hours click past.  BTW if
it's not top-hats it's something else you wish you had
that would save 3 hours!

>All in all, nothing particularly difficult or
>requiring exotic skills or materials, <snip>

Hey, hey, hey now, what you try to say here?!?
So easy a cave man could do it??? LMAO

> but experience >would save a lot of trial fitting
>and would 
>make the job look much better. 

Alright that's better 8^P

>With Jims' advice and >Fusa-Fab supply it has been
>quite achievable - but >I'm not sure I would have
>tackled it otherwise!
Regards
Mini Me (..[Technik] James) 

Hey James I hope I help as much as heckle!  Sorry but
last night I couldn't help but keep picturing you
running over to check that plate after reading my
email.  You may have found it before I wrote but it's
funnier the way I saw it!  I still can't help
chuckling when thinking about it but!  That's because
I've been there, done that, (redone that), LMAO!

All kidding aside I see you putting a lot of your time
in helping others on the list and then repeating it as
needed when new people join and re-ask.  Projects like
this allow me to offer that same help in the area I
know.  Sometimes a little moral support and a little
insight is all it takes to get someone started.  Kinda
what the EVDL is all about isn't it?

Had fun
Jim Husted
Hi-Trque Electric

 



 
____________________________________________________________________________________
Do you Yahoo!?
Everyone is raving about the all-new Yahoo! Mail beta.
http://new.mail.yahoo.com

--- End Message ---
--- Begin Message --- 
As far as I know the OEM tires on the "Classic" Prius (2001 - 2003)
are the Bridgestone Potenza RE92 XL P175/65R14
so a different load rating than the normal (non-XL) and a different
size than Jerry gave you. The XL is required for the Prius weight.
You can find the differences here:
http://www.tirerack.com/tires/Sizes.jsp?make=Bridgestone&model=Potenza+RE92


I think all US Prius from 2004 onward came with the same GY Integrity,
the UK version had a different 'tyre' IIRC, which goes with the 
upgraded brakes (disk brakes all around in the UK)

Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
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
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mark Brueggemann
Sent: Monday, March 05, 2007 11:47 AM
To: ev@listproc.sjsu.edu
Subject: RE: Prius OEM Tires

"jerryd" <[EMAIL PROTECTED]> wrote:

The Prius and now Insight are Bridgestone RE92 165-65's


"Shawn Waggoner, FLEAA" <[EMAIL PROTECTED]> wrote:

> My '07 Prius has Goodyear Integrity P185/65R15 tires on it


Thanks guys, that helped add a data point to my "tire collection".


Mark "EV Basher" Brueggemann
Albuquerque, NM
S-10 EV

--- End Message ---
--- Begin Message --- 
This is *only* true if a whole list of other parameters all have the same
values as well,
but two batteries wired to each other can just as well sit at very different
charge levels.

For example, if the temp of one battery is higher than the other battery,
then it will go to a different voltage.
This means that when they have the same voltage, they are at a different
state of charge.

There are many more parameters that affect the voltage and thus, the
difference between the state of charge on two connected batteries.
Simple example is the process for a NiMH battery, which cannot be paralleled
with several other identical batteries, as one may get into thermal runaway
and self-destruct from over-charging by the current the other batteries are
supplying to it.

This even happens on Lead packs.
Paralleled strings have failed to show good life, as is evident on US
Electricars.
Someone with 4 parallel strings measured charging current and found 2A into
one (the strongest string), 0.5A into the second and about 1/4A into the
last two strings. No wonder his range was down the tubes, while his pack was
relatively fresh.

The only good way to have batteries at the same charge level is to measure
(and control) their current in/out.

Putting regulators on them will allow them to float to the same "end" stop
(full charge), which is better than no regulation at all.

Cor van de Water
Systems Architect
Proxim Wireless Corporation http://www.proxim.com
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
Second Life: www.secondlife.com/?u=3b42cb3f4ae249319edb487991c30acb

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mick Abraham
Sent: Monday, March 05, 2007 9:54 AM
To: ev@listproc.sjsu.edu
Subject: Mick's answer to Lee Hart about BattEQ test

Lee Hart said:

"Start with two batteries at different states of charge. Connect them
directly in parallel -- they instantly go to the same voltage!"

Mick says: Check. The paralleled batteries instantly display an average
voltage. There is still a subtle delta-v, however, and that drives energy
movement until the batteries match. The current drops, the delta-v drops and
the battery differences approach zero. This does take time but eventually
results in near perfect equalization. The battery differences cannot vanish
unless the amperage transfer and the delta-v also vanish.

Once the batteries "settle out at the same state of charge" (to use Lee's
phrase), one battery is no longer trying to finish charge the other one.
Lee's hypothetical paralleled batteries would then share any
charge/discharge energy evenly, and there will never be a need to move x
number of amp-hours from one paralleled battery to the other.

If you clip a load onto the terminals of one battery which is parallel with
another, its voltage drops slightly compared to the other one, but the
difference can never become very great. As soon as the delta-v increases
energy moves through the parallel cables so that a state of charge
difference does not develop and no subsequent amp hour restoration is
needed. A BattEQ equipped series string behaves much the same as if the
batteries were in parallel, provided that the balancer is properly sized for
the application.
  
Lee said: "It only takes a small amount of force to keep something balanced
that is already almost perfectly balanced."

Mick says: The word "force" is very appropriate. Instead of waiting until
big "state of charge" differences have developed, BattEQ applies continual
force which scales up as needed to prevent SOC differences from occurring.
The PowerCheq(TM) product is similar in this regard, but the biggest
PowerCheq can only pump in the same power range as the smallest BattEQ
devices. Two amps of balancing current is fine for relatively small
batteries, but drive packs for golf carts or bigger would require the bigger
BattEQ units.

Lee said:
"For batteries that are well matched, or that aren't used much, you'll have
enough time for a low balance current to work." He later said: "...when
there are extenuating circumstances...the number of amphours needed to
restore balance gets larger. That's where higher power balancers like my
battery balancer come into play."

Mick says: Please do not equate BattEQ with "low balance current" and please
do not categorically state that other solutions are "higher power". I have
BattEQ units in stock which can pump 16 amps out from each channel
continuously. This can be verified by those who take the trouble. If that's
not enough, additional units could be added in parallel. Even with a big
balancer, the current goes no higher than that required to maintain balance.
As soon as one monobloc tries to outperform or under perform, the group will
receive "energy discipline" which scales up or down with the delta-v. With
unruly batteries, the balance current will ramp up until things realign or
until the design limit of the balancer is reached.

Even when the battery is being recharged, BattEQ does not burn off excess
energy through heat dissipation. Instead it pumps that into the monoblocs
that need it. With BattEQ one cannot detect high power in the form of hot
dissipaters atop a battery bank, because instead the power is going into the
weak monoblocs to improve the balancing process. 

Lee said: "For an EV, your "daily drive" will produce some degree of
imbalance. This can be expressed by how many amphours difference is required
to bring each battery back to the same state of charge. Then, you need a
balancing system that can produce this much charge differential per day."

Mick says: Lee's description above would be correct only if the balancing
system is deployed after the daily drive is complete. However, because
BattEQ works 24/7 the battery doesn't develop imbalances to be corrected
later with "10's of amp hours". Since BattEQ pumps energy in real time to
maintain alignment, the balancing game becomes one of instantaneous energy
transfer instead of amp-hour restoration after the fact. So long as the
instantaneous energy transfer is sufficient, there's never a need to correct
an accumulated state of charge deficit.

Mick Abraham
www.abrahamsolar.com

--- End Message ---

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