EV Digest 6811
Topics covered in this issue include:
1) Split pack DC/DC balancing
by "Adrian DeLeon" <[EMAIL PROTECTED]>
2) Re: Electric motor for air conditioning or power steering
by "Roland Wiench" <[EMAIL PROTECTED]>
3) Re: Raptor 600 problem
by [EMAIL PROTECTED]
4) Re: Split pack DC/DC balancing
by "Roland Wiench" <[EMAIL PROTECTED]>
5) Re: Thanks a lot Monster Garbage. I'll bet someone is happy.
by Lee Hart <[EMAIL PROTECTED]>
6) Re: Boost converter motor controllers
by Lee Hart <[EMAIL PROTECTED]>
7) Re: How regen works
by Lee Hart <[EMAIL PROTECTED]>
8) Re: Victor How regen works
by Lee Hart <[EMAIL PROTECTED]>
9) Re: Main Contactor Ebay Search Criteria
by Lee Hart <[EMAIL PROTECTED]>
10) Re: How regen works
by Lee Hart <[EMAIL PROTECTED]>
11) Re: Electric motor for air conditioning or power steering
by Lee Hart <[EMAIL PROTECTED]>
12) (no subject)
by Michael Haseltine <[EMAIL PROTECTED]>
13) Re: Ground and neutral connections for isolation transformer
by "Roland Wiench" <[EMAIL PROTECTED]>
14) 'EVs for Sale' on the web
by Jerry McIntire <[EMAIL PROTECTED]>
15) Re: Victor How regen works
by Victor Tikhonov <[EMAIL PROTECTED]>
16) Re:Go kart drag race safety vs mini-bike
by Bill Dube <[EMAIL PROTECTED]>
17) Re: How regen works
by Victor Tikhonov <[EMAIL PROTECTED]>
18) Fast and Eff!!! Re: White Zombie gets to 'test' drive Lithium!
by "jerryd" <[EMAIL PROTECTED]>
19) Re: Ni-Cad Final Taper
by "jerryd" <[EMAIL PROTECTED]>
20) Electric conversions in Austin receive recognition, rebate
by Christopher Robison <[EMAIL PROTECTED]>
21) RE: How regen works
by "Dale Ulan" <[EMAIL PROTECTED]>
22) Re: White Zombie gets to 'test' drive Lithium!
by "Andrew Kane" <[EMAIL PROTECTED]>
23) New EV - Thorr roadster
by Victor Tikhonov <[EMAIL PROTECTED]>
--- Begin Message ---
Before I plunk down $500+ on a DC/DC that can handle 450W at 110V nominal,
I was wondering:
If I paralleled two DC/DC converters, each connected to (almost) 1/2 the
pack, how bad would it alter the balance of my pack? I'm running 19
T-105s, so it's a 9/10 split on the batteries.
450W = 225W from each converter (assuming they share equally). That's
about 4.2A and 3.75A from each "half" of the pack. A difference of 0.42A.
At 100W output the difference drops to 0.19A.
Any ideas on keeping the current draws balanced? Would the 0.2 to 1 AHr
difference on a typical drive significantly unbalance my pack in the first
place?
-Adrian
.
--- End Message ---
--- Begin Message ---
Hello Guy,
You can see the top half of the accessory drive unit in
http://www.austinev.org/evalbum/470.html
Latter this summer, I am going to replace the 9 in Warp with the original
GE-11.5 inch that I had remanufacture. I will have to remove must of the
equipment you see, and will take exploded view pictures of the accessory
drive and how a GE traction motor is design for direct replacement of a
engine, that requires no additional adapter plates and motor mounts.
To gang these thread motors together, use a U-mount type. Weld the U mount
to the frame of the next motor. The U-mount has a adjustment slot, a bolt
hole for a long bolt which is about the same mounting system a alternator
has. I come off the top U-mount with a additional slotted mount bar, so I
now have a three fastener points.
The thread mill motor drive shaft is a metric 17 MM size, so I turn them
down to fit a 5/8 inch pulley. The pulley I use is a triple grove 2.5 inch
diameter taper lock type. I use a double industrial belt that goes around
both pulleys on each motor to turn the accessories unit, and one 3/8
diameter O-Ring belt that connects the two pulleys together for additional
power.
Roland
----- Original Message -----
From: "Guy Stockwell" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, May 24, 2007 8:55 AM
Subject: RE: Electric motor for air conditioning or power steering
> Roland,
>
> Do you have any pictures of your setup?
>
> Guy
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Roland Wiench
> Sent: Thursday, May 24, 2007 10:00 AM
> To: ev@listproc.sjsu.edu
> Subject: Re: Electric motor for air conditioning or power steering
>
> www.surplussales.com has 1000's of these thread mill motors in stock for
> about $20.00 each. They only problem is that you will have to reinforce
> the
>
> front sheet metal bearing holder. The bearing holder collapses in the
> direction of the belt pull. I use two 1/4 inch thick aluminum plates on
> both side of this flange.
>
> You can get these type of motors that have been improve and modified with
> enclose large brush holders from the Thread Mill Doctor for about $160.00
> each which are about 3 HP continuous.
>
> Also, these are about 8000 rpm at 100 volts at 1.75 hp and has a peak hp
> of
> 3 hp. I am using about 48 volts from four DC DC Iota converter in series
> which slows down these motors to about 4000 rpm and than using a 2:1
> pulley,
>
> it bring the rpm down to about 2000 rpm. Also I have gang two of these
> motor in parallel off the same belt which gives me 3.5 hp continuous or 6
> hp
>
> peak.
>
> I am running a alternator, A/C and vacuum pump which draws a peak ampere
> of
> 40 amps or about 20 amps per motor. Normally I am running at 13 amps per
> motor.
>
> I also running these accessories with the pilot shaft of the main motor
> using a electric clutch made from a clutch of a A/C unit as a back up and
> to
>
> assist the start up of these units, because the start up load may be at a
> greater rating of these motors.
>
> The motor is about 3-1/8 inch in diameter. I made a external fan holder
> and
>
> brush cover by slipping on a 3 inch I.D. PVC pipe which I increase the
> I.D.
> diameter to 3-1/8 and JB Weld on a plastic flange to hold a 12 volt box
> fan.
>
> Roland
>
>
> ----- Original Message -----
> From: "Tim Humphrey" <[EMAIL PROTECTED]>
> To: "EV" <ev@listproc.sjsu.edu>
> Sent: Thursday, May 24, 2007 7:06 AM
> Subject: RE: Electric motor for air conditioning or power steering
>
>
> >
> >
> >
> > There are 90vdc 1.5+hp PM treadmill motors on EBay all the time. Usually
> > less than 50 bucks. Why wouldn't one of those work?
> >
> > I was on my tread for 1.5hrs the other day, when I got off it my wife
> > got
> > on for another 30mins. I don't think duty-cycle will be a problem.
> >
> > --
> > Stay Charged!
> > Hump
> > I-5, Blossvale NY
> > >
> > > -----Original Message-----
> > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
> > > On
> > > Behalf Of Dustin Stern
> > > Sent: Wednesday, May 23, 2007 3:09 PM
> > > To: ev@listproc.sjsu.edu
> > > Subject: Re: Electric motor for air conditioning or power steering
> > >
> > >
> > > That's cheaper and lighter than the one offer by ElectroAutomotive -
> > > or
> > > that I've found anywhere else, as I've also been looking.
> > >
> > > By the way have you seen the electric compressor units at
> > > http://www.masterflux.com/ ?
> > > Although I can't seem to get an email reply, they have some ideal
> > > units.
> > >
> > > Dustin
> > >
> > > On May 23, 2007, Dewey, Jody R ATC COMNAVAIRLANT, N422G5G wrote:
> > >
> > >> Does anyone think that this motor will work to drive a power steering
> > >> pump or an AC pump?
> > >>
> > >>
> > >>
> > > http://www.e-motorsonline.com/emotors/viewproduct_dcm.php?catid=2&Pid=DC
> > >> M00116
> >
> >
>
>
--- End Message ---
--- Begin Message ---
Drive in the night time.
I have only seen faint flickers of the yellow light at full throttle. It
has never been solid on.
I don't know if this is an issue with my hall effect device or with the
Raptor.
I tend to think the problem is with the device, because my pedal travels
further than the full throttle point
--- End Message ---
--- Begin Message ---
Hello Adrain,
I am using Iota DC-DC converters, where the input can be either 120 VAC or
up to and over 180 VDC input.
All my units are connected across the 180 volts pack. Two contactors are
use to disconnected them from the pack and isolates them from the charger
circuit. The contactors also shuts down the power to the accessory drives
motors. This also prevents battery charger currents to appear on these
units.
The outputs are 13.5 to 14.5 volts. The output can be series together for
any voltage of 13.5 to 52 volts at 40 to 60 amps. You can also parallel
them together for more ampere.
I am adding 4 units where I can have a combination of any voltage and ampere
with a 5 wire output leads.
Roland
----- Original Message -----
From: "Adrian DeLeon" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, May 24, 2007 11:28 AM
Subject: Split pack DC/DC balancing
> Before I plunk down $500+ on a DC/DC that can handle 450W at 110V nominal,
> I was wondering:
>
> If I paralleled two DC/DC converters, each connected to (almost) 1/2 the
> pack, how bad would it alter the balance of my pack? I'm running 19
> T-105s, so it's a 9/10 split on the batteries.
>
> 450W = 225W from each converter (assuming they share equally). That's
> about 4.2A and 3.75A from each "half" of the pack. A difference of 0.42A.
> At 100W output the difference drops to 0.19A.
>
> Any ideas on keeping the current draws balanced? Would the 0.2 to 1 AHr
> difference on a typical drive significantly unbalance my pack in the first
> place?
>
> -Adrian
>
> .
>
>
--- End Message ---
--- Begin Message ---
Jorg Brown wrote:
I thought women would be as good as men at building things, assuming
that's where their interests were, but now that I've seen two (out of
two) all-women teams on monster garage go down into defeat, I know
better.
On the other hand, I've learned that it should be possible to turn a
car into an airplane in under a week! Man, I've been working on my
EV way too long; that would be sooooo much cooler!
ps Is there any one of us who wouldn't fire Jesse in his first week,
if we were stuck working with him?
Absolutely! I'd replace him with any of my BEST teams of students. They
really *are* talented and energetic, and get things done!
We just had this year's 10th annual BEST races last Saturday. The EVs
these 4th-6th graders invent, build, and race are truly amazing. (PS:
The girls typically build better cars than the boys!)
--
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 ---
Jeff Major wrote:
Hi Lee,
Interesting approach. Using the motor field as the
boost inductor. But you may find some issues. Look
at the example. If it was a 12 amp rated 72 volt
series motor, then the fields would have about 50
times the loss, not to mention saturation. If it was
a 100 amp rated 72 volt motor, then at 12 amps
armature current it would be derated by a factor of 8.
The field was wound for the application, so the motor losses were no
different than usual. It had the armature from a 100v motor and the
series field from a 12v motor. This is the main reason why the motor's
torque-speed curves were basically unchanged.
I don't know the IR intended application, but on the
face of it, maybe not well suited for propulsion.
This was an application note to demonstrate an SCR boost converter; they
didn't mention the final application. They say the principle advantage
(from the motor's point of view) is that you can use a higher voltage
armature, which is easier to make and has lower brush losses. Also, the
motor torque at high rpm is no longer limited by the supply voltage,
because you can boost it at least 10:1. The circuit is suitable (with a
12v supply) for motors of 10hp or less.
The bidirectional buck-boost converter with separate input
inductor might be the ideal way to go.
This could be done, too. But as I posted, the problem with the
buck-boost converter is high input and output ripple (requiring more
capacitors), and high stress levels on the semiconductors.
--
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 ---
Dale Ulan wrote:
a lot of ACIM controllers do not have a separate regen circuit - the
boost function is only done via software control of the 6-pack in the
right manner...?
For motor-only operation, there are 6 switches (transistors, SCRs,
MOSFETs, IGBTs, or whatever) in the traditional 3-phase bridge inverter.
There is no path for current to flow back into the battery (so no regen).
But most implementations add 6 more power semiconductors; 6 diodes
across each switch. These allow you to do regen.
These diodes are "free" if you use MOSFETs -- MOSFETs have an
unavoidable reverse diode in them as part of their nature. However, they
aren't very good diodes, so if a controller uses them, the maximum regen
current won't be as high as the maximum motoring current.
All other switch technologies require that these diodes be added
somehow. IGBTs usually include them inside the same package. SCRs and
bipolar transistors require separate chips/packages to add them.
Finally, it should be noted that you need extra control system functions
to get regen. This may be easy or hard, depending on you you implemented it.
--
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 ---
An AC motor's back EMF (generated voltage) is proportional to speed,
just like a DC motor's. As the speed approaches zero, the generated
voltage approaches zero. Since the pack voltage is fixed, the controller
has to boost the voltage by a larger and larger percentage as the speed
drops. For example, at 10 mph it might be generating 10 volts, so you
have to boost the voltage 30:1 to charge a 300v pack. At 1 mph its
generating 1v, requiring a 300:1 boost.
For various design reasons, it gets expensive and complicated to try to
boost the voltage too much. The engineers have to give up on regen below
some speed, or the controller gets too expensive to sell.
One alternative is to switch to plug braking below some speed. The
inverter can also be programmed to *short* the motor, or apply straight
DC to it. This isn't regen (it *consumes* power from the batteries); but
it still brakes the motor. I believe this is what Solectria does.
--
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 ---
England Nathan-r25543 wrote:
Just curious what a capacitor across the main contacts would do as arc
suppression.
"Snubber" circuits work no matter what the size of the contacts or load.
For a little 120v 1amp switch, a 0.1uF capacitor and 100 ohm resistor
is about right (that's what you'll find in all sorts of consumer products).
For the main contactor in my ComutaVan (72v, 200amps), I used a 2000uF
capacitor with 24" of #18 wire as the resistor. This considerably
reduced arcing.
You'll still have to deal with the insulation strength and open contact
spacing -- they have to good for the voltage you are trying to switch.
For example, a single contact will need 1/2" or more spacing at 120vdc.
You might be able to adjust the open contact spacing this large, but
then the solenoid probably can't pull it in without a considerably
higher coil voltage.
--
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 ---
(-Phil-) wrote:
Yes, I'm assuming that whatever controller design is in the loop is
going to limit at it's max rating. If you built a controller without
any kind of current limiting, obviously.... BOOM!
Yes; but the controller's maximum regen current rating is far higher
than an 80% SOC battery's max rating!
If you pull out of your driveway every morning at the top of a steep
hill, you will not want to regen for the reasons you state, (or just
never fully charge before you shove off!
As it happens, I *do* live at the top of a steep hill. If I let my EV
roll down the driveway to the street (50 feet), it will be going about 5
mph. If I allow full regen, the motor will generate over 400 amps; you
get a violent lurch that's enough to skid the tires, and push the fully
charged 12v batteries up to 16-18 volts. This is bad news; likely to
break things!
for most EV driving, it isn't going to be a problem to regen at high
levels (controller limiting).
I'm afraid it is. You can't apply high charging currents (100s of amps)
to batteries over 80% SOC. You don't want your daily driving to
discharge them deeper than 50% SOC (or you'll shorten their life). So
you can only allow high regen currents during 3/5th of your daily
driving (when the pack is between 50% and 80% SOC).
Low-level regen (to simulate ICE engine braking) is much less of a
problem. The batteries can withstand brief 20-50 amp surges even when
fully charged.
The Prius isn't a fair comparison, as it's going to be charging while
you drive, rather than only once before you start off on your trip.
As it happens, I have a Prius, too. When you park, it tries to leave the
pack at about 80% SOC. When we drive down that big hill next morning, we
have to use the friction brakes; there's no room in the batteries for
the regen energy.
So, we use an alternate strategy. We drive up the big hill, but halfway
up, we let up slightly on the accelerator so the ICE shuts off, and let
it motor up the rest of the hill electrically, so the pack is partially
discharged when we get to our garage. Next morning, going back down that
hill, the pack *does* have room for high regen current (about 40-50 amps
into the 274v pack of 6.5ah batteries). The hill will put about 100
watthours into the pack.
Obviously you need some way for the driver to control regen current,
either through a brake pedal pot/encoder, or just by letting off the
main throttle (my favorite).
The Prius gives you "engine braking" if you release the accelerator
pedal, and stronger regenerative braking when you step on the brake
pedal. They made it work to exactly copy the feel of a normal car with
automatic transmission. Without instruments, regen is invisible.
My old Datsun pickup EV had the second kind of regen you mentioned (let
up the accelerator to control regen). With an aircraft generator as its
motor, I had *huge* amounts of regen; release the accelerator too much,
and you'd bang your head on the windshield and skid the tires,
generating 500+ amps back into the pack! The accelerator behaved a lot
like a cruise control; hold it in a steady position, and it tried to
hold a steady speed, up hills and down, doing strong motoring or strong
regen as needed. Once I got used to it, it was OK; but it was a big
problem for guest drivers!
For a commercial EV, you wouldn't want this kind of regen, it would
probably scare/confuse the drivers.
Exactly!
--
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 ---
Tim Humphrey wrote:
There are 90vdc 1.5+hp PM treadmill motors on EBay all the time.
Usually less than 50 bucks. Why wouldn't one of those work?
I was on my tread for 1.5hrs the other day, when I got off it my wife
got on for another 30mins. I don't think duty-cycle will be a
problem.
Measure the actual AC power consumption; you'll find it isn't even
remotely close to enough to support that advertised 1.5 hp.
Some of these treadmill motors are built pretty well; others are near
junk. But all of them are incapable of delivering their advertised
horsepower for more than a brief time.
--
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 ---
All this excitement over the AGNS minibike reminded me of the gokart
that was in the same league (12.102 sec. at 102.71mph) a few years
back that blew my mind, and in tracking it down found that the NEDRA
website says the gokart class has been dropped for safety reasons.
Can it be any different than for minibikes? BTW, I'm certainly not
thinking that the minibike class should also be dropped!! Rather the
other way round.
--
Michael Haseltine
--- End Message ---
--- Begin Message ---
Hello Chris,
In installation of a isolation transformer, you can have a 240 volt 3 wire
primary and a 120/240 volt secondary. The 120 volt is the center tap or
call the neutral point between the two line leads in the secondary.
The 240 volt 3 wire primary is two line wires going to the transformer and a
ground wire to the electrical enclosures the transformer is house in.
The 120 volt 3 wire secondary ground is not connected the same transformer
electrical enclosures but is connected to all the secondary electrical
enclosures which must be isolated from any metal connections that can back
feed to the building ground system.
You develop a ground at this neutral connection. Meaning you connect a
neutral (white wire) and a ground (green wire) at the transformer center
neutral connection.
This ground is now call a isolated ground. If you happen to ground this to
a steel building or building electrical chassis, then it becomes
non-isolated, because you connected the secondary ground to the building
grounding system.
To prevent these grounding systems to become connected, you must use a
isolated 120 vac 3 wire receptacle or a isolated 240 vac 4 wire receptacle.
Isolated receptacles are normally color code orange and you will notice that
the grounding strap in these receptacles are not self grounding to the
outlet box.
For isolated ground circuits, we use a green wire with a yellow tracer. You
can also mark this ground wire with yellow tape.
A GFCI does not need a ground wire, for these receptacles to work. It
measures the unbalance between the two power carrying lines. The only thing
you will not be able to do is to test the GFCI receptacle. The test button,
shorts out the neutral and ground inside the receptacle.
All new installations of GFCI or receptacles require a grounding wire, with
exception of rewiring of 2 wire old receptacles circuits, which we can
install a GFCI on the first receptacle that's comes from the circuit breaker
panel on the existing 2 wire circuits.
We must then install a receptacle plate this is states: GFCI RECEPTACLE -
NO GROUND CONNECTION.
Go ahead and develop a ground circuit at the neutral at the secondary of the
transformer. They only thing is that you do not ground the secondary ground
at the electrical enclosures, other wise you are connecting the primary
ground with the secondary ground.
My battery charger in my EV is grounded with the standard building ground
system, but the battery charger enclosure is install inside a 1/4 thick
epoxy coated fiberglass enclosure which isolates from the steel of the EV.
It like having a off-board charger not touching the EV.
A onboard GFI 50 amp circuit breakers is use. The power plug and connector
to my EV and a isolated connector and plug, where the receptacle ground
strap is not self grounding to the vehicle.
In a complete isolation system, there should be no voltage conductance
between any battery post and the frame of the vehicle while you are
charging.
If you do show some current, than install additional contactors between the
battery and main contactor and controller. Another place where a conductive
path will developed is from the motor commentator down the face of the
commentator to the motor shaft which is cause by brush dust. If you do not
have two isolation contactors in the circuit, this is where the frame will
pick up the charging circuits.
This is what causes the GFCI devices to trip. The only time for the GFCI
devices should trip, is you are touching a battery terminal, while the
batteries are being charge and you are standing bare footed in a puddle of
water.
Roland
----- Original Message -----
From: "Chris Tromley" <[EMAIL PROTECTED]>
To: <ev@listproc.sjsu.edu>
Sent: Thursday, May 24, 2007 9:33 AM
Subject: Ground and neutral connections for isolation transformer
> Still (slowly) working on getting my charging setup complete. (Boy
> will it be nice to charge at more than the 9 amps my one shaky 120V
> breaker can provide.)
>
> Here's my layout. My power meter is mounted on my garage wall.
> There's a separate box for a Time Of Use meter. (I think those were
> for running your dryer at night at a lower off-peak rate.) The TOU
> meter isn't installed, but a cable comes from that box into the garage
> to a separate service entrance box. This is the line I'm using to
> charge. I'll run some NM-B cable to a rainproof outside box with a
> NEMA 14-50 outlet and a 50 amp GFCI breaker.
>
> I also have a big isolation transformer that I'd like to put on this
> circuit, preferably between the service entrance panel and the outside
> box. It's 5 kVA, can take up to 480 VAC and has center taps, so it
> should be up to the task. I know my PFC20 doesn't need a neutral, but
> I'd like to wire this up as properly as possible.
>
> I may be an electrical dummy, but I know enough to realize that
> grounds and neutrals can confuse even the pros. Throwing isolation
> and GFCI into the picture doesn't help.
>
> Here's what (I think) I know. The two hots from the service entrance
> panel go to the primary of the transformer, no connection to the
> primary center tap. Ground from the outside box goes direct to the
> service entrance box and is bonded to the enclosure. The hots of the
> receptacle are connected to the ends of the transformer secondary.
> Here are my questions:
>
> 1. Should the receptacle neutral be connected to the center tap of the
> transformer secondary? I know that will give the 120VAC you'd expect,
> but this isolated neutral won't be connected to ground at the service
> entrance panel.
>
> 2. Will the GFCI work properly this way? My thinking is that the
> isolated voltage has no reference to ground, so you could
> theoretically grab a hot in one hand, a ground in the other and never
> feel a tingle - the GFCI would do nothing, nor would it need to.
> Unless of course you have an isolation failure. Then you would have a
> path to ground and the GFCI would trip as expected, correct?
>
> Any advice would be greatly appreciated. I'd really like to get this
> right. Just a thought, do the codes regarding "isolated ground"
> circuits (those orange outlets you see in office buildings) have any
> relevance here? If not, let's not even bring them up - that's a whole
> 'nuther subject that confuses the pros. ;^)
>
> Thanks,
> Chris
>
>
--- End Message ---
--- Begin Message ---
Bruce,
The 1986 Toyota MR2 for sale in Sunnyvale is now priced at $11,800.
Jerry
SF, CA
http://sfbay.craigslist.org/sby/car/336398709.html
Toyota MR2 Electric Vehicle - Plug In Vehicle - $15800 (sunnyvale)
--- End Message ---
--- Begin Message ---
Don,
More often than not I see this in your responses:
[EMAIL PROTECTED] wrote:
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I could read your question by viewing source, so here is reply:
Victor you there?
This made me curious about what is being said about AC regeneration. I
had a
Solectria Force and it would bring the vehicle to a complete stop. The
factory Ranger and S-10 EVs do not have any adjustments and they roll
off the
regeneration as you slow down. I know when we talked about the Siemens
AC system
it sounded great that you could adjust it to ones personal needs. Does
an AC
system lose regeneration at slow speeds as being bought up here? The
Solectria Force would bring you to a complete stop on a hill so it
seems odd to me
this is being brought up that AC regeneration will not work at slow speeds?
Don,
In ACRX, just like in your Solectria you can practically stop using
regen. I start loosing regen at below 3-4 mph, but if the car is on
first gear, it drops to well below 1mph. I have steep drive way and
if I roll down on first gear you can slowly walk next to the car.
All depends on how fast the motor spin, inverter works as boost
converter, so as long as it generated enough voltage (for it's given
fixed inductance) inverter will be able to boost it to the required
battery voltage. In my case ~1mph is enough to get ~up to 380VDC out
so you'd feel max braking force down to 1mph. Below 3-4mph you loose
regen. I only use brakes to hold the car still if I stop in traffic
on non-flat street.
Of course, I use regen pot to gradually control degree of regen.
Victor
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The safety issues of go karts on the drag strip are not obvious, but
quite serious.
It is all about traction, polar moment, and wheelbase. Karts spin and
flip easily on the drag strip.
The traction on the drag strip is three times what it is on the
street or a go kart track. When one rear tire loses traction, (hits a
greasy spot) the other pushes the kart into a spin. The polar moment
of a kart is tiny, and the sticky track gives huge force to the wheel
with traction, so the spin is almost instantaneous. There is no time
for the driver to react, lift the throttle, and steer the kart straight.
The kart is wide and short, so the rear wheel that has
traction has too much leverage on the CG and can easily overpower the
steering traction of the front wheels. Even if you steer quickly
enough, the rear tire with traction has enough force to make the
front tires skid sideways, so steering has no effect.
On the kart track, if the kart gets sideways, it just slides
sideways. On the drag strip, the traction is so good that the tires
dig in and the kart flips instead of sliding.
Thus, a small greasy section on the track is all it takes to
spin and flip the kart because it happens so fast. A car with more
polar moment, longer wheelbase, and narrower track might just weave a
bit over the same greasy spot.
With a motorcycle, there is only one back tire. If it loses
traction briefly, the bike still goes straight down the track. Losing
traction briefly does not cause a bike to instantly spin and flip,
like it will a kart on the drag strip.
It isn't at all simple, is it? That is why NEDRA originally
allowed karts, because we didn't know any better in the beginning.
Bill Dube'
At 11:13 AM 5/24/2007, you wrote:
All this excitement over the AGNS minibike reminded me of the gokart
that was in the same league (12.102 sec. at 102.71mph) a few years
back that blew my mind, and in tracking it down found that the NEDRA
website says the gokart class has been dropped for safety reasons.
Can it be any different than for minibikes? BTW, I'm certainly not
thinking that the minibike class should also be dropped!! Rather the
other way round.
--
Michael Haseltine
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Dale Ulan wrote:
At low speeds the regen might go away, maybe Victor or other AC
users can chime in?
It will go away at so low speeds that it may be considered full
stop as far as traffic is concerned. I can tune it in software
to be at about 2 mph.
About loosing regen going off-hill when fully charged.
This is actually my situation. First, you don't completely
loose regen, system reduces battery current to stay below
max voltage, but there is some current flowing into the
battery to maintain that voltage (if current would be zero,
no regen, voltage would drop to about nominal allowing full
regen again).
If my off-hill run would be steeper/longer, I just would
purposely undercharge by the amount I will gain going down.
So I never loose regen and I'm full by the time I'm at the
bottom of the hill, and it's easy to measure. But this is
hypothetical situation. I just use disk brakes near bottom,
got to clean rust off of them anyway. No big deal.
Victor
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Hi John and All,
----- Original Message Follows -----
From: John Wayland <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Subject: White Zombie gets to 'test' drive Lithium!
Date: Wed, 23 May 2007 23:09:04 -0700
>Hello to All,
>
>With our first runs of the year in the 12.1 range again,
>Killacycle's flirting with the 7s, and now 'Lawless Shawn'
>tearing up the track, 2007 is fulfilling the prophesy of
>being of being the best drag racing EV performance year
>yet! How cool is all this, that it's timed perfectly for
>the celebration of NEDRA's 10 year anniversary?
It has been a great yr, let's not forget ProEV, SCCA
SE Fla Champion winner too!! While I'm not that into drag
racing, it's a great tool of your, Bill Dube's websites,
vids, really impress many who I've turned on to them and
really help turn EV atitudes around to much more positive
ones in the public. Thanks to all you racers!!
>
>Before pulling White Zombie's injured motor last Saturday
>(now in Jim's loving hands), I had the fun of driving it
>about 14 miles to and from the Albertson Distribution
>Center's digital weigh scales a few days ago. The Enersys
>(Hawker) batteries (360V nominal) laughed at this trip and
>were sitting at 379V right after turning off the key when I
>got back home. Moments later they were at 383V before I
>put it on charge. It took 5.3 ahrs to replenish what 14
>miles took from the pack. The 360V twin pack is rated at
>32 ahr C10, and at the reduced cruise current a 360V car
>has at the 35-45 mph speed limits of this trip there's
>probably 20 ahr of usable EV capacity...that works out to
>52 miles range. Not too bad for a 12 second drag car!
You forgot an important number, it took only 140-150
wthr/mile for it's trip!! Not bad for an EV breathing down
the 11sec 14 mile bracket!! This is an important item for
you to mention as it's the equivilent of 300mpg cost wise or
between 100-300mpg energy wise depending on your electric
costs hile putting muscle cars to shame at the track ;^D.
Assuming they consider hydro 100% eff and you probably
charge by hydro, you can say you get 300mpg or so.
Sadly cool, light cars like Datsun 1200's for eV
conversions are rare and getting more so.
>
>The bad news, White Zombie at present, weighs nearly 2600
>lbs. Yes, I said nearly 2600 lbs.! I was pretty disgusted
>to see that the '07 version of White Zombie with all of
>its 840 lbs. of lead in it, even with the new 30+ lbs.
>lighter battery compartments, weighs in at a porky 2580
>lbs.! With me in it (speaking of porky) the scales
>accurately jumped up to an even 2800 lbs....yikes! Still,
>in March this 2580 lb. car ran a 12.161 at close to 107
>mph, that, with the still-new and un-broken-in battery
>pack restricted to just 1000 amps. It can make up to 1500
>amps.
>Now...doing all the above, then pulling out 840 lbs. of
>lead and replacing it with a 175 lb. lithium pack (Dube's
>spare bike pack will be on loan for the day at the Wayland
>Invitational III) makes an 1831 lb., ~ 300 hp machine!!!
That's going to be wicked!! Bet your wthr/mile drops
to under 120wthr/mile if you can keep your foot off the
floor ;^D
Keep up the great work guys, you are inspirng many!!
Jerry Dycus
>
>Before the exciting July races though, the mighty Enersys
>pack will be called on to deliver more power than it did
>in March, as we will turning up the screws and will be
>running at a higher 1200 battery pack amps as we again,
>reach for the 11s.
>
>
>See Ya.....John Wayland
>
>11 in 07!
>
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Hi Mark and All,
----- Original Message Follows -----
From: "Mark Hanson" <[EMAIL PROTECTED]>
To: ev@listproc.sjsu.edu
Subject: Ni-Cad Final Taper
Date: Wed, 23 May 2007 07:12:10 -0500
>Howdy Folk's,
>
>I was curious on my STM5-180's the manual says they will
>taper off charge above 8V per battery (block is the French
>term). I'm trying to decide whether or not to put more
>turns on the secondary of my ferro-resonant transformer.
>It's tapering off at 1.66V per cell or 8.28V per battery
>which may be a bit low.
That sounds just right to me though to cut watering,
longer life, I only did that every 5 cycles or so, charging
to 80-90% other times.
I think the TE-Van's were around
>1.73V per cell or 8.65V but that could be a bit high, not
>sure. The manual says to final taper current at 7.5A but
>I think that's a bit much, I'm at C/40 4.5A and they gas
>quite a bit. The new guy at Saft didn't know. Does anyone
>know what the final taper voltage is typically on these
>flooded ni-cads?
I did C-1 charge to the end without problems though
mine are high power cells!! I'd stick to around
1.60-1.65/cell, maybe 1.70/cell if they seem to be out of
balance though mine always got better balanced as I used
them. Mine were SAFT 14amphr versions of the BB600 style and
seriously abused and live still over rated capacity, power,
over 33 yrs old now ;^D
Jerry Dycus
>
>See you at the June 3-7 Wind Expo in LA,
>Have a renewable energy day,
>Mark
>
>
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Hey folks,
Wanted to spread some good news, on a local level but perhaps as an
example that other communities could follow and expand.
Austin Energy and Central Texas Clean Cities had previously created a
rebate program under which purchasers of electric vehicles (bikes,
scooters, cars) could receive a rebate from $50 to $250. A modest
amount, but an important showing of support from the city:
http://www.ci.austin.tx.us/cleancities/electricvehiclerebate.htm
Today, it's been announced that the rebate now applies to converted
electric cars as well. Many thanks go to Mark Kapner who championed this
decision within Austin Energy. I think this represents one of the few
examples currently out there, of official recognition of the benefits of
converted electric vehicles.
The announcement is included below.
-----------------
AustinEV and Austin Energy are pleased to announce the Electric Vehicle
Conversion Rebate program.
As of May 23, 2007, any Austin Energy customer who has purchased a newly
converted electric vehicle or who has completed a conversion themselves
may apply to receive up to a $250.00 rebate from Austin Energy. This
groundbreaking move matches the efforts that Central Texas Clean Cities
and Austin Energy have made in supporting production, neighborhood and
low speed electric vehicles, scooters and bicycles, indicating that the
EV conversion specialist and EV enthusiast can also be a part of this
clean air and alternative fuel transportation solution. Progress towards
a sustainable future for our Austin, TX communities is the priority.
To apply for your rebate, please download and submit the rebate
application and submit it to Austin Energy upon the completion of your
vehicle.
http://www.austinev.org/evinfo/local/austin-energy-rebate.html
The rebate program begins May 23, 2007 and covers conversions that are
completed after that date. Applicants must be Austin Energy customers.
Austin Energy will certify that the vehicle has been converted to run on
electric power before issuing the rebate.
--
Christopher Robison
[EMAIL PROTECTED]
http://ohmbre.org <-- 1999 Isuzu Hombre + Z2K + Warp13!
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But most implementations add 6 more power semiconductors; 6 diodes
across each switch. These allow you to do regen.
You need those diodes anyways, so that the inductance of the
motor creates an averaged current (the low-frequency AC component)
out of the 5-20kHz PWM signal applied. Without those diodes it'd
blow up even when motoring. Well, a MOSFET would survive because
of its intrinsic diode but the IGBT wouldn't.
..aren't very good diodes, so if a controller uses them, the maximum regen
current won't be as high as the maximum motoring current.
Unless you use synchronous rectification - which uses the MOSFET in
reverse. You probably want to do that anyways to lower the losses.
-Dale
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Yep, that was me... I'm looking forward to the Invitational even
though y'all will be tardy. Hey now- Killacycle in the 7's and WZ in
the 11's on 7-11-07 would be too perfect even for a numerologist.
But that's what I'll be thinking of when I'm blowing out the
candles on my birthday keg.
On 5/24/07, Jim Husted <[EMAIL PROTECTED]> wrote:
--- John Wayland <[EMAIL PROTECTED]> wrote:
> With
> Killacycle shooting for the 7s and our quest for the
> 11s, I like the
> ring of it...Oh thank heaven, for 7 - 11! (credit
> Jim Husted for making
> the 7 - 11 connection)
Hey John, credit where credits due, it wasn't I who
chimed this first. Can't remember who it was but I
believe it was EVen their birthday. To bad the race
will fall 2 days late of the date 7/11/7 8^)
For me on top of the awesome things people are doing
this year has been the feeling that as a group we are
growing and that the comrodery is also growing.
Anyway just wanted to set the facts straight, I
already take more credit than is due 8^P
Cya
Jim Husted
Hi-Torque Electric
____________________________________________________________________________________Pinpoint
customers who are looking for what you sell.
http://searchmarketing.yahoo.com/
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All,
Here is short introductory video of Thorr - roadster EV
which will be marketed (with sufficient demand in USA too) by
EVISOL - Metric Mind's European partner:
http://pub.tv2.no/nettavisen/bil/article1062524.ece
Sorry, interviews are only in North Germanic (or is it Danish?)
The vehicle has been successfully introduced in Norway already.
On this video Thorr has lead acid test pack. Production version
of course is lithium. Granted, AC drive; this version on the
video is standard 100 kW system.
I had privilege to drive Thorr while in Netherlands. Terrific and
fun vehicle, based on Lotus chassy.
I have to coordinate with EVISOL any additional info I can release.
Will keep EVDL posted.
Victor
--
'91 ACRX - something different
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