EV Digest 4359
Topics covered in this issue include:
1) Re: Heat and Charge (Cogeneration?)
by Lee Hart <[EMAIL PROTECTED]>
2) TdS Report #31: Western Washington University Team Members, Michael Seal
by [EMAIL PROTECTED]
3) RE: PFC50 for sale
by "prime" <[EMAIL PROTECTED]>
4) Re: Energy to store/make energy source, was Re: 2005 HONDA FCX
by Fortunat Mueller <[EMAIL PROTECTED]>
5) RE: Heat and Charge (Cogeneration?)
by "Bill Dennis" <[EMAIL PROTECTED]>
6) Very Arcane auto. Aluminium
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
7) Re: Electravan charge connector fix
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
8) RE: Heat and Charge (Cogeneration?)
by "Bill Dennis" <[EMAIL PROTECTED]>
9) Re: Heat and Charge (Cogeneration?)
by "Philip Marino" <[EMAIL PROTECTED]>
10) RE: Rear wheel idea for fully enclosed MC
by "Mark Fowler" <[EMAIL PROTECTED]>
11) Re: Motor horsepower estimations and questions (Rich, I could use your
insight)
by Ryan Stotts <[EMAIL PROTECTED]>
12) Re: Inexpensive DC/DC converters
by Neon John <[EMAIL PROTECTED]>
13) RE: Motor horsepower estimations and questions - some comments
by "John Westlund" <[EMAIL PROTECTED]>
14) Saft BB600s - disappointing results?
by "Christopher Robison" <[EMAIL PROTECTED]>
15) Re: Heat and Charge (Cogeneration?)
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Inexpensive DC/DC converters
by Rod Hower <[EMAIL PROTECTED]>
17) BC-20 Question
by "Bill Dennis" <[EMAIL PROTECTED]>
18) RE: Vicor DC-DC VI-N(B)52-EM (from Halted)
by "Myles Twete" <[EMAIL PROTECTED]>
19) Re: Heat and Charge (Cogeneration?)
by Lee Hart <[EMAIL PROTECTED]>
20) Little LiIon cells again
by "John G. Lussmyer" <[EMAIL PROTECTED]>
21) EV Transmissions
by "John G. Lussmyer" <[EMAIL PROTECTED]>
--- Begin Message ---
Bill Dennis wrote:
> I'm thinking about giving this a try. Conceptually, it would look
> like this:
>
> 220V AC --> 120V Heating Element(s) --> Rectifier/Filter --> 150V
> (Peak) Battery Pack --> Ground
>
> By changing the number of heating elements that are paralleled,
> different charging amps can be chosen.
I think I'd keep the water heater's stock 220v heating elements. When
you are NOT charging your EV, these elements are wired and work
normally, to provide hot water.
When you want to charge your EV, these elements are wired in series or
parallel to give you three different charging current steps
(low-medium-high).
The bridge rectifier is AFTER the water heater elements and their
thermostats and series/parallel contactors. This way, all these parts
are switching AC as they normally would. Basically, this means you cut
one of the "hot" wires to the water heater and connect the ends to the
AC inputs of the bridge rectifier.
The output of the bridge rectifier is of course non-isolated DC. Treat
it accordingly! It could charge pretty much anything from a single 6v
battery to a pack totalling almost 240v. The charging current would of
course be limited by the heating element's resistance.
This charger should only be used for "bulk" charging (0% to 80% SOC). It
is too crude and uncontrollable for the finesse needed to reach full
charge. Finish the job with a smaller, lower-current, well regulated
charger.
> Is there a good rectifier/filter I can buy that can handle up to
> 150V and 60A, with minimal DC ripple?
Prepackaged bridges are generally only good for up to 30amps. They may
advertise them as 40amp or 50amp, but in reality you can't cool them
enough to actually survive at these currents.
If you really think you'll get 60 amps (depends on the size of the
heating elements you use), you'll need to use four separate diodes.
Mount them on a big heatsink, or perhaps to the copper water pipe going
into the water heater (to recover the heat from the diodes, too :-)
The diodes should be rated to at least 600 volts to survive on 240vac
line. The additional cost for 800 or 1000 volt diodes is trivial, so I'd
use them.
You won't need any filtering. As I said, this should only be used as a
bulk charger, where ripple doesn't matter.
Sounds like an interesting idea! Let us know how it turns out!
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
TdS Report #31: Western Washington University Team Members, Michael Seal
After the press conference on Thursday, I got a chance to talk with Emily
Morris, Brian White, Matt Willson, Ryan Cruse, Kate Stenson, Calvin Liu and
Sean Aylward who are some (all?) of the team members for Viking 23 and 32.
Ryan: "I'm a huge car dork and I've recently become concerned about our
environment. This allows me to be a car dork and a responsible car dork."
They said they were all pretty much responsible car dorks. There are two
different aspects to the technology program at WWU. One is the CAD/CAM
(Computer Aided Design / Computer Aided Manufacturing) programs that
concentrate on design. The other is the VRI (Vehicle Research Institute)
that involves people in the actual construction, tuning and competing.
The other two teams are Formula which builds race cars and Mini-Baja which
builds off-road vehicles. "They are not responsible dorks."
I first saw a hybrid vehicle when WWU's Viking 21 competed in the Tour de Sol
in 1993. Few of us really understood what it was all about back then. (I know
it took me a long time to see the point of two different drive systems in one
vehicle.) Now I can buy six different hybrids from three different
manufacturers. Where does a program like VRI go from here?
"We need to improve all the systems that are out there right now; pioneer some
new ones, more efficient ones." There is a need to fight the stereotypes of
hybrids being slow. "We can show that a hybrid can save fuel, still go fast
and be fun to drive."
Will there be hybrids at NASCAR and other races?
The electric motor in a hybrid gives lots of torque which will definitely be
appreciated in a race car.
VRI is starting to look into different fuels. Viking 32 is sometimes run on
bio-methane from cow manure, which is another facet of the program.
Viking 32 was pretty new the last time it was at the Tour. It has about 9000
miles on it now. "We've had some fun going on some curvy roads. It handles
very well. It is very stable at high speeds." The electric motor on the front
wheels helps pull it out of tricky situations. A two-speed transmission on the
front is shifted by an electric solinoid driven by a computer that also
balances power between the front (electric) and rear (combustion engine)
drives.
They have considered driving the Vikings to the Tour, but being fueled by CNG
(Compressed Natural Gas) makes finding fuel tricky. They have considered
driving up to Canada where they have many more CNG stations and then coming
back down, but it makes the trip much longer.
Later, I had some time to talk with Michael Seal, retired advisor to the
Viking teams. I asked why Viking 32's doors were hinged at the back.
"The were called couch doors. The reason for it was that you don't have to
open the door very far and you can get in quite nicely. If you are parked near
another car, you can still get in the front seat quite easily." Viking 32 has
four seats. "With the hinge in the front and a long door, you can only get in
the back in tight situations. But they fell out of favor because they flew
open and caught the wind. Then the door was gone. They became known as
suicide doors. "With modern technology there is no reason for a door ever to
open accidentally, because of the modern latching systems. Some of the
Japanese show cars are starting to have doors hinged at the rear."
Viking 32 can run at two heights. With the suspension at the elevated position
it can run in deep snow, and you have a bit better vision in traffic. The
low position is 4 inches lower. That gives a lower center of gravity, less air
going under the car, and the front wing (built into the front bumper) and the
rear wings provide additional down force for stability. The car automatically
lowers when moving more than 30 miles per hour, or it can be set in the low
position manually. "The geometry is correct when up or down, but during the
transition the wheels have a slightly negative camber." A hydraulic cylinder
above the suspension connects to a tiny link wishbone and controls the
elevation. The spring, shock absorber and inner wishbone pivot all move as
one. "It is quite light, with a very small weight penalty. The power steering
pump is used to power the transistion."
"Because the whole thing is made of carbon fiber, the body, chassis,
everything, it weighs just over 2000 pounds; about what a Triumph TR2 or TR3
weighed. So we have the weight of a light weight, 2-seat, squeeky sports car
in a stiff, monocoque 4-seat car." It has 100 electric horsepower in front and
100 CNG horsepower in the rear.
- - - -
The complete set of Tour de Sol Reports for 2005 can be found at:
http://www.AutoAuditorium.com/TdS_Reports_2005
The complete set of past Tour de Sol Reports can be found at:
http://www.FovealSystems.com/Tour_de_Sol_Reports.html
- - - -
The above is Copyright 2005 by Michael H. Bianchi.
Permission to copy is granted provided the entire article is presented
without modification and this notice remains attached.
For other arrangements, contact me at +1-973-822-2085 .
- - - -
For more on the NESEA Tour de Sol, see the web page at
http://www.TourdeSol.org
- - - -
Official NESEA Tour de Sol information is available from the sponsor,
the Northeast Sustainable Energy Association (NESEA) at
413 774-6051 , and 50 Miles Street, Greenfield, MA 01301 , and
[EMAIL PROTECTED] . All media enquiries should be addressed to ...
Jack Groh
Tour de Sol Communications Director
P.O. Box 6044
Warwick, RI 02887-6044
401 732-1551
401 732-0547 fax
[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
I am very much interested in the PFC50 on ebay. I have 2 early 90's G vans
that need a charger. The configuration is 216v nominal and 30 amps would
probably do. Before I get into a bidding war :>} with someone else on the
list. I have an idea. Perhaps someone that wants the PFC50 or someone else
has a charger that will do what I want. If so it could save both of us some
$$$.
Bill Sibner
--- End Message ---
--- Begin Message ---
--- [EMAIL PROTECTED] wrote:
> Other than PV=nRT, I don't know how to figure the
> energy it takes to compress H2
> down to 360atm's - is there a constant value per
> 3.8kg of hydrogen at room temp
> (25 C)? That probably also has to assume 100%
> efficient compressor, etc.
yeah, this isn't that easy to calculate. I guess you
can calculate the lower limit (isentropic
compression).
I don't usually trust myself to do math, but I get
something like :
18000 kJ/kg (or about 5 kW-hr per kg). Seems like the
right order of magnitude anyway. Obviously the real
energy input will be higher since this is a lower
bound.
> And along the same lines of inquiry, does anyone
> know how much electricity the
> average gallon of gasoline takes from crude oil to
> finished product?
I am not an expert in the refining process, but
according to the GREET well to wheels model,
California RFG has a well to pump efficiency of about
81 %. I don't know how much of the 19% is electricity
and how much is fuel energy lost along the way. But
that 19% would be about :
33,000 kJ/gal or about 9 kW-hr/gal (if it were all
electrical input, which i am sure it isn't).
disclaimer : these numbers are worth what you paid for
them.
~fortunat
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Thanks, Lee. I will be using this to bulk charge my TS and Nicad cells, and
I didn't know how the TS cells would take to the 60Hz pulses that would
occur without filtering.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: Saturday, May 14, 2005 10:30 AM
To: [email protected]
Subject: Re: Heat and Charge (Cogeneration?)
Bill Dennis wrote:
> I'm thinking about giving this a try. Conceptually, it would look
> like this:
>
> 220V AC --> 120V Heating Element(s) --> Rectifier/Filter --> 150V
> (Peak) Battery Pack --> Ground
>
> By changing the number of heating elements that are paralleled,
> different charging amps can be chosen.
I think I'd keep the water heater's stock 220v heating elements. When
you are NOT charging your EV, these elements are wired and work
normally, to provide hot water.
When you want to charge your EV, these elements are wired in series or
parallel to give you three different charging current steps
(low-medium-high).
The bridge rectifier is AFTER the water heater elements and their
thermostats and series/parallel contactors. This way, all these parts
are switching AC as they normally would. Basically, this means you cut
one of the "hot" wires to the water heater and connect the ends to the
AC inputs of the bridge rectifier.
The output of the bridge rectifier is of course non-isolated DC. Treat
it accordingly! It could charge pretty much anything from a single 6v
battery to a pack totalling almost 240v. The charging current would of
course be limited by the heating element's resistance.
This charger should only be used for "bulk" charging (0% to 80% SOC). It
is too crude and uncontrollable for the finesse needed to reach full
charge. Finish the job with a smaller, lower-current, well regulated
charger.
> Is there a good rectifier/filter I can buy that can handle up to
> 150V and 60A, with minimal DC ripple?
Prepackaged bridges are generally only good for up to 30amps. They may
advertise them as 40amp or 50amp, but in reality you can't cool them
enough to actually survive at these currents.
If you really think you'll get 60 amps (depends on the size of the
heating elements you use), you'll need to use four separate diodes.
Mount them on a big heatsink, or perhaps to the copper water pipe going
into the water heater (to recover the heat from the diodes, too :-)
The diodes should be rated to at least 600 volts to survive on 240vac
line. The additional cost for 800 or 1000 volt diodes is trivial, so I'd
use them.
You won't need any filtering. As I said, this should only be used as a
bulk charger, where ripple doesn't matter.
Sounds like an interesting idea! Let us know how it turns out!
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
This design is still fresh today. It would make a great EV. When I first
saw it I thought it was an EV1. Just shows that the U. S. had some great
autos in mid century that are to this day EV candidates.
http://www.suarezweb.com/davis/ Check the links for some great photos.
Lawrence Rhodes
Bassoon/Contrabassoon
Reedmaker
Book 4/5 doubler
Electric Vehicle & Solar Power Advocate
[EMAIL PROTECTED]
415-821-3519
--- End Message ---
--- Begin Message ---
That is a great simple solution. How close does the switch have to be to
the magnet to activate? I'd like to hide the switch. I'd still have to
drill out the sheet metal from behind the cover and the reed switch would
have to fit under the cover. Maybe super gluing the magnet to the cover
lid. But too late now. Another option it to put the reed switch next to
the recessed male connector. It's just plastic. Glue a magnet on a stick
to the cover and have it just miss the pins and activate the reed switch
that way. No drilling needed. Are magnets ferous? The ones commercially
made seem to have a lot of mineral content. Not sure what the base metal
is. Aren't there plastic coated magnets? Yes magnet on the cover and reed
switch next to the recessed male connector. Should work great. I love this
list. LR.........
----- Original Message -----
From: "Lee Hart" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, May 13, 2005 9:51 PM
Subject: Re: Electravan charge connector fix
Lawrence Rhodes wrote:
OK I think I found a solution for the 4 prong connector and safety
for shock. I replaced the Hubbel with a Bryant 71530NC and
associated flanged recessed male. ($130 for both yikes) The safety
switch was a little harder...
Sounds like you have a workable solution, Lawrence.
Here's another approach that is fairly easy to implement. If the housing
is mostly non-ferrous (not steel), you can drill a hole and epoxy in a
magnet into the cord-mounted connector. Then put a reed switch on the
outside of the receptacle, next to where the magnet is when mated. Now
the reed switch will close when the magnet is present. The reed switch
can control power to the coil of a relay or contactor, whose contacts
can prevent "drive-aways" or connect the pack to the connector, etc.
--
"The two most common elements in the universe
are hydrogen and stupidity." -- Harlan Ellison
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Lee Hart wrote:
>Basically, this means you cut one of the "hot" wires
>to the water heater and connect the ends to the
>AC inputs of the bridge rectifier.
Like this, I think, right?
+-----------+
+-------+ | |
()-- Black --| | | +--|>-+-|>--+ +---------+
| Water | | | | | |
()-- White --|Heaters| | +--+ Bridge +----O Cells O---+
| | | | | | | | |
+- Red ----| | | | | | | | |
| +-------+ | | +--|>-+-|>--+ +---------+ |
| | | | |
+---------------------+ +--------|----------------------+
|
()--- Back to AC (Also Red) --------+
Thanks again.
Bill Dennis
--- End Message ---
--- Begin Message ---
If you really need only 150V DC maximum, you may be able to use a different
configuration (similar to a full-wave center-tap supply) where you only two
two discrete diodes. One diode is connected to each side of the 220 line.
The other ends of the diode ( same polarities) are connected to each other.
The battery goes between the junction of these two diodes and the neutral
power conductor.
Here your max voltage would be limited to 220/2 * 1.4 - one diode drop, or
about 153 volts. Since "220" lines are usually closer to 230 volts, you
may end up with about 160 V max.
The main advantage is that you won't have to dissipate huge amounts of power
in your heating elements, so your total power out of the wall would be less
- exactly half the power used by the 220, full wave bridge configuration
for the same charging current.
If you can make good use of all of that extra power ( in the full-wave
configuration) then it might not make much difference, but I would be
concerned about overheating the water in your water heater with all of that
power for several hours.
You can still add resistance ( preferably, 2 elements with the same
resistance) between each of the 220 connections and your diodes ( to control
the current) , but, since these would only have to drop a few (10 to 20?)
volts, and not 120 V or more, the power in the resistance elements would be
much less.
You could do a similar thing with a single 110 outlet if it had enough
current capability. In that case you would just use a full wave bridge. (
and you would only need a single resistance element, although the power
dissipation of that one element would be the same as for both elemtents in
the 220V center-tap design.)
Any comments, Lee?? Would this make sense?
Phil Marino
By the way, the power factor on each of the 220 legs would be pretty poo
with a center-tap bridge, but there would still be less average ( and RMS)
current on each of the 220 legs than with the full-wave bridge you are
considering. So, if the full-wave bridge setup will work with your 220 line
( without tripping a breaker) , this setup will also work, and at higher
charging currents than the full-wave setup.
From: Lee Hart <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: [email protected]
Subject: Re: Heat and Charge (Cogeneration?)
Date: Sat, 14 May 2005 10:29:46 -0700
Bill Dennis wrote:
> I'm thinking about giving this a try. Conceptually, it would look
> like this:
>
> 220V AC --> 120V Heating Element(s) --> Rectifier/Filter --> 150V
> (Peak) Battery Pack --> Ground
>
> By changing the number of heating elements that are paralleled,
> different charging amps can be chosen.
I think I'd keep the water heater's stock 220v heating elements. When
you are NOT charging your EV, these elements are wired and work
normally, to provide hot water.
When you want to charge your EV, these elements are wired in series or
parallel to give you three different charging current steps
(low-medium-high).
The bridge rectifier is AFTER the water heater elements and their
thermostats and series/parallel contactors. This way, all these parts
are switching AC as they normally would. Basically, this means you cut
one of the "hot" wires to the water heater and connect the ends to the
AC inputs of the bridge rectifier.
The output of the bridge rectifier is of course non-isolated DC. Treat
it accordingly! It could charge pretty much anything from a single 6v
battery to a pack totalling almost 240v. The charging current would of
course be limited by the heating element's resistance.
This charger should only be used for "bulk" charging (0% to 80% SOC). It
is too crude and uncontrollable for the finesse needed to reach full
charge. Finish the job with a smaller, lower-current, well regulated
charger.
> Is there a good rectifier/filter I can buy that can handle up to
> 150V and 60A, with minimal DC ripple?
Prepackaged bridges are generally only good for up to 30amps. They may
advertise them as 40amp or 50amp, but in reality you can't cool them
enough to actually survive at these currents.
If you really think you'll get 60 amps (depends on the size of the
heating elements you use), you'll need to use four separate diodes.
Mount them on a big heatsink, or perhaps to the copper water pipe going
into the water heater (to recover the heat from the diodes, too :-)
The diodes should be rated to at least 600 volts to survive on 240vac
line. The additional cost for 800 or 1000 volt diodes is trivial, so I'd
use them.
You won't need any filtering. As I said, this should only be used as a
bulk charger, where ripple doesn't matter.
Sounds like an interesting idea! Let us know how it turns out!
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
_________________________________________________________________
Express yourself instantly with MSN Messenger! Download today - it's FREE!
http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/
--- End Message ---
--- Begin Message ---
I think the tilting rear wheel concept is a good idea.
Yes, the spoked wheels are ridiculous, and could easily be changed.
The concept that the bike changes its balance characteristic from a
three wheeler at low speed to a two wheeler at high speed is brilliant.
As a parent who has taught a couple of kids to ride bikes over the last
few years, the biggest hurdle is to get the kids to "unlearn" how to
ride a trainer wheel bike.
A trainer wheel bike teaches kids to rely on the trainer wheels to keep
them upright in turns - and so they learn to lean out. If they try to
lean in, they come up against the inside trainer wheel, sometime lifting
the main wheel off the ground.
Anyway, for an enclosed MC, this idea gives stability when stopped or
moving very slowly, would allow low speed reversing, and gives the
ability to lean steer at higher speeds.
Yes, there is a lot more engineering involved to make a concept like
this into a suitable practical motorcycle - many hurdles to be overcome
(as Lee has listed) but I think the idea has a lot of merit.
As for the mechanism that tilts the wheels depending on speed, I can
imagine they used something similar to the centrifugal governor on a
steam engine to do the tilting.
The faster it spins, the more it brings the wheels in.
Mark
--- End Message ---
--- Begin Message ---
John Westlund wrote:
> I'd prefer my peak horsepower at higher rpm if it meant
> sacrificing torque, as I'm not going to be able to use more
> than 250 lb-ft anyway, as that will pose a risk of breaking
> tranny/diff, and I want those portions of the car to stay
> Triumph components.
What kind of tires are you planning on running?
--- End Message ---
--- Begin Message ---
On Sat, 14 May 2005 06:56:40 -0700, "Chris Brune"
<[EMAIL PROTECTED]> wrote:
>Hi John,
>The datasheet for the SD350 family indicates that it come in one of 3 input
>voltage variants:
>B: 19-36, C: 36-72, D: 72-144. Each of these three input ranges covering
>the 2:1 input range they quote.
>If you have a 72V system you might expect that your actual battery pack
>voltage would vary from around 60 volts to about 90V.
>Thus I don't see where one of the specified input ranges would cover your
>needs.
I discussed this with an application engineer. The voltage range is
nominal. If the absolute voltage rating is exceeded the unit shuts
down to protect the FETs, according to him. This is expected
behavior, I think, since it's hard to imagine a high voltage DC/DC
application NOT involving some sort of battery system. Since I plan
to interlock the control system with the charger so that none of the
controls are energized during charging, that problem will be solved
anyway.
>I would also comment that you need to be careful about these types of power
>supplies. They aren't designed to be mounted on a vehicle. They won't be
>protected against water intrusion.
Mine goes in the passenger compartment so that's not an issue.
>If you leave your converter connected
>all the time does the fan run all the time?
I forgot to ask the apps guy but I bet that it has a smart fan that
only runs when necessary. Heck, even my cheapie $29 inverters have
that feature. This converter will not be energized during charging so
that's not a problem anyway.
With my Citi I can take a bit different approach for accessory power
than for larger and more accessorized cars. The total electrical load
is <300 watts. The converter can supply all the loads. The 17ah
Hawker Genesis battery that I use for accessories is just for surges.
It should remain charged most all the time. If not then there is a
small smart charger already installed to keep the accessory battery
topped off. I'm currently running a Group 24 wet deep cycle battery
sitting in the floorboard until I get the converter installed. The
small charger gets the job done with that battery so it should work
well with the other.
In my design the pack is completely insolated (DP contactor) during
charging. I don't want to have to worry about voltage excursions,
line conducted transients and other rot affecting any of the
electronics while the charger is connected.
>
>There are companies out there that make converters designed for 72V on
>vehicle operation.
Yeah, I know but IMHO, they are grossly overpriced. Seems like EV
parts are like medical parts. Throw on the "EV" label and the price
explodes. Oh I know the usual arguments about low volume,
yadayadayada, but that's not for me.
First off, I'm an engineer and as such, the journey is half the fun.
What fun is there in just bolting on purpose-made parts? Adapting
parts to the application is part of the fun.
Second, I'm a cheap b*stard. I learned years ago that if I pay a LOT
of attention on the buying end then I don't have to work so hard on
the earning end to get the things I want.
Anyway, we'll see how this unit works when I get it. If the blue
smoke leaks out, well not that much lost.
John
---
John De Armond
[EMAIL PROTECTED]
http://www.johngsbbq.com
Cleveland, Occupied TN
--- End Message ---
--- Begin Message ---
Philip Marino wrote:
>I chose the 8" because the significantly lower
>efficiency of
>the 6.7" ( at the typical currents I expected to use)
>meant that I would
>have reduced power and range. The higher efficiency of
>the larger motor more
>than made up for the extra weight. You may also find
>that the larger motor
>is a better choice in your case, for the same reason.
I'm keeping weight in mind not for efficiency, but mostly
for handling and not going too far over GVWR. This car is
1,793 pounds stock, and can be stripped down to about an
1,150-1,200 pound glider. The engine alone is just over 400
pounds, not counting its accessories. I have to fit as large
a battery pack as possible to get about 40% of total weight
in batteries, and GVWR is 2,350 pounds. I figure 2,600
pounds is the max limit I should go to given the comments I
recieved from others on various British Car forums. But I'll
likely keep it around GVWR, with use of fiberglass
components and a drastic diet on this car.
>BUT, the benefit of the larger motor may only become
>apparent
>if you look at real data at high currents. It may not
>show up if you just
>use the manufacturers' data at 400 amps and below.
Still hunting for the data at higher currents. I'm sure many
are, which is why so many want John Wayland to get his
dynoed.
>To get a better current torque relationship, you need
>some real data at the
>high current levels you expect to use. (Rich - or
>other high-power guys -
>may be good sources for this data). Then , you could
>try to fit the wider
>-range curve with a more complex curve.
Indeed. But I went with the straight line relationship since
if I use the equation T = k*i^n and take the constants for
the ADC9'' from Uve's EV page, I get nearly 400 pound feet
of torque with 1,000 motor amps. This is completely
incorrect from what I've gathered on these forums, because
at that RPM, motor efficiency is only about 55% or so.
>Sag might not be a factor, but the pack voltage is.
>The maximum torque is
>controller ( current) limited. But, the higher the
>available (battery)
>voltage, the higher the motor RPM at which you can
>supply this
>current-limited maximum torque, so the higher the peak
>horsepower.
But the Zilla allows the user to set a max motor voltage
limit, unlike DCP controllers or the Curtis. I've heard
bringing an ADC motor above 160 volts or so with 1,000 amps
or more going through it is a BIG no no. The WarP 9'' is
rated at 192V, and I'm uncertain whether is would be wise to
go higher than that, hence my selected limit of 192V. If it
could handle, say, 240V with 1,000 amps going through it,
I'd be making a huge amount of power for an EV, almost near
the level of California Poppy.
Thanks for your advice. I know my equations are inaccurate,
as they're estimations. It would be nice if I had a reliable
method to model these motors, but above 500 amps or so, I'd
have to resort to making numbers up, or in the case I use
certain constants provided from certain web pages, I get
numbers that are way too good to be true.
But as they say, information is worth what you pay for it.
Ryan Stotts wrote:
>What kind of tires are you planning on running?
I'm planning some 14 inch aluminum LeMans style rims, and
fitting some Nokian NRT2s onto them. According to
greenseal.org, they have a .0085 coefficient rolling
resistance. Size 185/70R14. Apparantly they have excellent
traction, especially for such a low Cr.
Stock, my GT6 came with 13 inch rims, so the 14 inchers will
have slightly greater interia losses, but the change in
overall gearing would give me more top speed.
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--- Begin Message ---
I've been testing a few of my designated "sacrificial" Saft BB600 cells
this afternoon, with results I'm not sure how to interpret. Hoping to get
current capacities similar to what I've heard about the legendary Marathon
BB600s, I have been running them through a length of 4/0 cable with a
3000A shunt and matching meter. Terminating the cable are heavy copper
lugs with 1/4" holes for fastening to the cells and the shunt, and the
800A solid copper clamps from Waytek, which I have "augmented" by
inserting the 4/0 copper strands through the handle all the way to the jaw
where I welded them in place.
I tried clamping on to various lengths of wire, getting shorter and more
in parallel until I finally just clamped the two clamps together. With a
single cell shorted through a total of about 5 feet of 4/0 and that
massive 3000A shunt, I got about 750A.
Two cells in series through a sandwich of two flattened 3/4" pipes as an
intercell connector made about 1100A. Three cells connected the same way
made about 1400A. Though I don't have many data points yet, the current
gained with additional cells seems to be falling significantly. Also, at
1400A, cell voltage fell to around 0.4V. The copper bus bars were getting
very hot, and the cells were warming noticeably.
Questions: How low of a voltage sag is "too low" with these cells? Also,
should I expect a "breaking in" period similar to lead acid? Are there
ways I could improve my testing methods? Should I just keep adding cells
to see how many amps I can get? I assume per-cell voltages will drop lower
as I do this; is this correct?
--chris
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--- Begin Message ---
Bill Dennis wrote:
>
> Lee Hart wrote:
>
> >Basically, this means you cut one of the "hot" wires
> >to the water heater and connect the ends to the
> >AC inputs of the bridge rectifier.
>
> Like this, I think, right?
>
> +-----------+
> +-------+ | |
> ()-- Black --| | | +--|>-+-|>--+ +---------+
> | Water | | | | | |
> ()-- White --|Heaters| | +--+ Bridge +----O Cells O---+
> | | | | | | | | |
> +- Red ----| | | | | | | | |
> | +-------+ | | +--|>-+-|>--+ +---------+ |
> | | | | |
> +---------------------+ +--------|----------------------+
> |
> ()--- Back to AC (Also Red) --------+
Yes, that it!
--
*BE* the change that you wish to see in the world.
-- Mahatma Ghandi
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
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--- Begin Message ---
Most of the DC/DC converters will go below the
nameplate rating but are derated in current (unless
they have an undervoltage lockout, but most likely not
until you reach 60Vdc). I say go with it! John's
willing to experiment and maybe we can all benifit.
Rod
--- Neon John <[EMAIL PROTECTED]> wrote:
> On Sat, 14 May 2005 06:56:40 -0700, "Chris Brune"
> <[EMAIL PROTECTED]> wrote:
>
> >Hi John,
> >The datasheet for the SD350 family indicates that
> it come in one of 3 input
> >voltage variants:
> >B: 19-36, C: 36-72, D: 72-144. Each of these
> three input ranges covering
> >the 2:1 input range they quote.
> >If you have a 72V system you might expect that your
> actual battery pack
> >voltage would vary from around 60 volts to about
> 90V.
> >Thus I don't see where one of the specified input
> ranges would cover your
> >needs.
>
> I discussed this with an application engineer. The
> voltage range is
> nominal. If the absolute voltage rating is exceeded
> the unit shuts
> down to protect the FETs, according to him. This is
> expected
> behavior, I think, since it's hard to imagine a high
> voltage DC/DC
> application NOT involving some sort of battery
> system. Since I plan
> to interlock the control system with the charger so
> that none of the
> controls are energized during charging, that problem
> will be solved
> anyway.
>
> >I would also comment that you need to be careful
> about these types of power
> >supplies. They aren't designed to be mounted on a
> vehicle. They won't be
> >protected against water intrusion.
>
> Mine goes in the passenger compartment so that's not
> an issue.
>
> >If you leave your converter connected
> >all the time does the fan run all the time?
>
> I forgot to ask the apps guy but I bet that it has a
> smart fan that
> only runs when necessary. Heck, even my cheapie $29
> inverters have
> that feature. This converter will not be energized
> during charging so
> that's not a problem anyway.
>
> With my Citi I can take a bit different approach for
> accessory power
> than for larger and more accessorized cars. The
> total electrical load
> is <300 watts. The converter can supply all the
> loads. The 17ah
> Hawker Genesis battery that I use for accessories is
> just for surges.
> It should remain charged most all the time. If not
> then there is a
> small smart charger already installed to keep the
> accessory battery
> topped off. I'm currently running a Group 24 wet
> deep cycle battery
> sitting in the floorboard until I get the converter
> installed. The
> small charger gets the job done with that battery so
> it should work
> well with the other.
>
> In my design the pack is completely insolated (DP
> contactor) during
> charging. I don't want to have to worry about
> voltage excursions,
> line conducted transients and other rot affecting
> any of the
> electronics while the charger is connected.
>
> >
> >There are companies out there that make converters
> designed for 72V on
> >vehicle operation.
>
> Yeah, I know but IMHO, they are grossly overpriced.
> Seems like EV
> parts are like medical parts. Throw on the "EV"
> label and the price
> explodes. Oh I know the usual arguments about low
> volume,
> yadayadayada, but that's not for me.
>
> First off, I'm an engineer and as such, the journey
> is half the fun.
> What fun is there in just bolting on purpose-made
> parts? Adapting
> parts to the application is part of the fun.
>
> Second, I'm a cheap b*stard. I learned years ago
> that if I pay a LOT
> of attention on the buying end then I don't have to
> work so hard on
> the earning end to get the things I want.
>
> Anyway, we'll see how this unit works when I get it.
> If the blue
> smoke leaks out, well not that much lost.
>
> John
> ---
> John De Armond
> [EMAIL PROTECTED]
> http://www.johngsbbq.com
> Cleveland, Occupied TN
>
>
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--- Begin Message ---
I bought an old BC-20 charger to play around with. Without the LB-20
transformer, the BC-20 is rated for a 108V battery pack, max. In reading
the documentation, though, I noticed that the unit had built-in temperature
compensation. If the temperature is cold enough, the KB-20 will charge to
2.8V per cell. So for a 108V system, that would be: 54 * 2.8 = 151.2V. As
we've been discussing with the water heater idea, my pack needs only around
148.75V.
So, I was wondering if it would work to fool the BC-20 into thinking that
the temperature is -30C. And if so, is there anyone on the list familiar
enough with a BC-20 to tell me how to do it? If it were possible, then I
wouldn't need to LB-20, saving weight in the EV.
Thanks.
Bill Dennis
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--- Begin Message ---
Joe Smalley indicated:
> The B modules have no control circuitry, they need to be
> clocked by a driver module.
Anyone got inside information on the detailed differences between Vicor
Booster and Driver modules? I've got a boatload of 48v 150w modules, but
they're all drivers. I want to make the drivers act as boosters, i.e.
receive var. freq. pulses from adjacent driver or booster as command, then
pass on var. freq. pulses to next booster. I confirmed that the drivers
will accept, use and pass on the freq. pulses correctly, but whenever the
pseudo-booster kicks in, it screams loudly. With all the output sense wire
combinations I've tried I can't get rid of the noise/oscillation. There's
still lots of things I haven't tried (including changing sense loop gains),
but just wondering if anyone out there has either successfully gotten a
driver module to work just like a booster, or if anyone has internal
functional diagrams showing the differences. You'd think that if the
boosters are just like drivers (but minus the sense circuitry) that you
could simply pass the gate signals through it and disconnect the output
sense wires....while this works, the beast sings like a banshee...
I realize I'm probably pioneering this.
Once successful making a driver act as a booster, I'll load up 3 Vicor PFC
Megapac units with 8 150w modules each (7 pseudo-booster w/1 driver module),
for 3.6kw of charging possible. Later I'll add 3-stage charge capability.
-Myles Twete, Portland, or.
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--- Begin Message ---
Philip Marino wrote:
> If you really need only 150V DC maximum, you may be able to use
> a different configuration (similar to a full-wave center-tap
> supply) where you only use two discrete diodes. One diode is
> connected to each side of the 220 line. The other ends of the
> diodes (same polarities) are connected to each other. The battery
> goes between the junction of these two diodes and the neutral
> power conductor.
This works, but draws halfwave DC current pulses on each half of the
220v line. In general, this is a bad idea. The power factor is poor,
efficiency is lower, and any transformers supplying these two half-wave
phases will run hotter and have less power capability.
If this is what you want, it is better to just connect a bridge
rectifier to single phase 120vac. Then the AC line current is
symmetrical, its power factor is better, so efficiency is better and
transformers won't overheat.
--
*BE* the change that you wish to see in the world.
-- Mahatma Ghandi
--
Lee A. Hart, 814 8th Ave N, Sartell MN 56377, leeahart_at_earthlink.net
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--- Begin Message ---
I don't know if anyone wants to experiment some more (I remember somebody
was...), but Electronic Goldmine has some 1.2AH, 3.7v cells for 99c each,
part # G14948.
I don't know how useful they are since they don't have solder tabs.
http://www.goldmine-elec.com
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream.... http://www.CasaDelGato.com
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--- Begin Message ---
I was just wondering...
Has anyone tried finding a planetary or (umm, whatever the configuration of
the gears in a differential is) transmission that could be used in an EV?
We really don't need a lot of speed choices.
A differential type transmission with 2 band brakes, and 2 clutches could
give 1:1, 2:1, and -1:1 choices - which look like a pretty good set of
choices for an EV.
It seems like there must be SOMETHING out there with this kind of
transmission, used in the power range we need.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream.... http://www.CasaDelGato.com
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