EV Digest 5295
Topics covered in this issue include:
1) RE: Recommendations on Relays
by "Bill Dennis" <[EMAIL PROTECTED]>
2) Oozing Joints
by "Bill Dennis" <[EMAIL PROTECTED]>
3) Ovonics licences and limitations featured on WIRED's Autopia - see last
paragraph
by "Mike Ellis" <[EMAIL PROTECTED]>
4) Re: Congratulations to Matt Graham and Lowell Simmons!
by "Mike Ellis" <[EMAIL PROTECTED]>
5) Re: Oozing Joints
by Ricky Suiter <[EMAIL PROTECTED]>
6) RE: Oozing Joints
by "Roger Stockton" <[EMAIL PROTECTED]>
7) Re: Oozing Joints
by Dave Cover <[EMAIL PROTECTED]>
8) 28 guage wire & crimps
by Mike Phillips <[EMAIL PROTECTED]>
9) Re: Testing Contactors - Results
by Lee Hart <[EMAIL PROTECTED]>
10) RE: Oozing Joints
by "Bill Dennis" <[EMAIL PROTECTED]>
11) RE: Oozing Joints
by "Bill Dennis" <[EMAIL PROTECTED]>
12) Re: Fast Street Car with Twin DC Motors
by James Massey <[EMAIL PROTECTED]>
13) Re: Testing Contactors - Results
by Rod Hower <[EMAIL PROTECTED]>
14) Re: Testing Contactors - Results
by Rod Hower <[EMAIL PROTECTED]>
15) Re: Trippy breaker
by Lee Hart <[EMAIL PROTECTED]>
16) Re: Peak Detector
by Lee Hart <[EMAIL PROTECTED]>
17) Re: Oozing Joints
by Neon John <[EMAIL PROTECTED]>
18) RE: Fast Street Car with Twin DC Motors
by "Roger Stockton" <[EMAIL PROTECTED]>
19) Re: DC-DC converter: How to select?
by Neon John <[EMAIL PROTECTED]>
20) Re: STM5-100
by "John Luck Home" <[EMAIL PROTECTED]>
21) Re: DC Motors for Racing (and Matt's Nissan 200SX)
by "Rich Rudman" <[EMAIL PROTECTED]>
22) RE: DC Motors for Racing (and Matt's Nissan 200SX)
by "Roger Stockton" <[EMAIL PROTECTED]>
23) RE: Fast Street Car with Twin DC Motors
by "Jay Brown" <[EMAIL PROTECTED]>
24) Re: Single Transistor Battery Charger
by Lee Hart <[EMAIL PROTECTED]>
--- Begin Message ---
Thanks, Roland. I'll take a look at those parts. I haven't had much luck
with the electrical supply companies here in Salt Lake City, but there's
always hope.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Roland Wiench
Sent: Tuesday, March 28, 2006 5:21 PM
To: [email protected]
Subject: Re: Recommendations on Relays
Hello Bill,
Try wholesale electrical supply houses, that sell General Electric,
Westinghouse, Cutler Hammer, Square D and etc.
If you cannot purchase direct from them, then go to a electrical company and
have them get them for you. Sometimes they will give you a purchase order
and you can get them yourself.
I am using glass plug in relay with spade terminals that plug into a surface
mounted relay sockets that have set screw wire connections.
The relay type is Square D Class 8501 - Type R. There is a range of coils
voltage and contacts ratings of 6 to 120 VDC and 6 to 240 VAC.
The relay socket is Class 8501 - type N
The relay fits so tight in the socket, that I not using any relay retainer
clips, but they are only $0.66 each.
I am using a 240 VAC - 10 amp rating for switching 180 volts DC of only 1
amp to a set of safety contactors with 180 vdc coils, and another one for
switching 12 volt DC of 4 amp to the main contactor with a 12 volt coil.
I using a three pole type, so I have 2 spares contacts in place. This relay
has been running since 1975 and I still have a spare relay that I have not
used yet.
Across the coils of these contactors, I using a NTE4999 Zenar Overvoltage
Transient Suppressor-Bidirection to suppress the arcing on the relays.
The web site is: http://www.squared.com
Roland
----- Original Message -----
From: "Bill Dennis" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Tuesday, March 28, 2006 3:56 PM
Subject: Recommendations on Relays
> I'm having trouble finding a couple of relays that I need for my EV. Both
> should have 12V coils. One needs to switch 150V max. The other needs to
> switch 48V max. Both will carry less than one amp. Couldn't find them on
> Digi-key or any of the EV sites. Anyone know where I can purchase them?
>
> Thanks.
>
> Bill Dennis
>
>
--- End Message ---
--- Begin Message ---
Thanks to the good advice I received here, I've been able to use a long cord
and break in my motor at 12V. The car is up on jack stands, and I've been
running for about 8 hours now. I've noticed quite a bit of brown grease
leaking out of the CV joints. Is this normal, or does it indicate a
problem?
Thanks.
Bill Dennis
--- End Message ---
--- Begin Message ---
http://wiredblogs.tripod.com/cars/
Plug-In Hybrids Get More Clout
*Now Playing:* Ludwig van Beethoven
*Topic:* Hybrids
Add a few significant names to the roster of folks that want to make plug-in
hybrids a commercial reality. Quantum <http://www.qtww.com/<br>> Fuel
Systems Technologies and a former GM exec are the latest members of the Plug-In
Hybrid Development Consortium <http://www.hybridconsortium.org/>.
Quantum has done powertrain and prototyping work for the Big 3 in Detroit as
well as the U.S. Army and Toyota, so they provide valuable technical
expertise. Alan Perriton is a former senior executive of General Motors
Asia/Pacific, so he could help with industry pull.
So far the leading hybrid vehicle companies have said they aren't working on
plug-in hybrids due to the technical limitations of the batteries, but I've
heard rumors that they may be hamstrung by licensing issues.
Some industry insiders have told me on background that battery makers and
auto companies that have licenses from ECD
Ovonics<http://www.wired.com/news/technology/0,70346-0.html>,
which invented the nickel metal hydride battery, are contractually
prohibited from developing batteries that are powerful enough to meet the
plug-in demands. I haven't been able to get a confirmation of this on the
record, but it adds an interesting twist as to why plug-ins aren't getting
industry support despite consumers excitement.
--- End Message ---
--- Begin Message ---
Direct link to the forum discussion:
http://forums.nicoclub.com/zerothread?id=165513
-Mike
On 3/27/06, Matthew D. Graham <[EMAIL PROTECTED]> wrote:
>
> I heard one guy say, "I can't believe there's an electric car at the
> track!"
> I said, "Well sure. . .and there's another electric car right there--the
> Porsche. In fact, we just held an all-electric race here in January!" It
> was
> perfect! Another guy that I was talking with for a while brought up the
> Nissan Infiniti Car Owners club (nicoclub.com) and I mentioned that yes,
> I'd
> been on there before. In fact, I'm still waiting for my five-lug
> conversion
> hubs I heard about there so I can put the 16" wheels up front, too. He was
> saying how I should post something about the car, and I said I definitely
> would. Of course, he beat me to the punch and posted about Joule Injected
> later that same night, and there's been a raging thread going on since
> then!
>
--- End Message ---
--- Begin Message ---
If the CV joints are oozing that means there's a rip in the rubber boot, and
this is not good. Dirt will get in there and eventually wear out the joints to
the point that you will have clicking when you turn a corner, and if it gets
that bad it will have to be rebuilt or replaced.
Your best bet it to get that fixed sooner than later.
Bill Dennis <[EMAIL PROTECTED]> wrote:
Thanks to the good advice I received here, I've been able to use a long cord
and break in my motor at 12V. The car is up on jack stands, and I've been
running for about 8 hours now. I've noticed quite a bit of brown grease
leaking out of the CV joints. Is this normal, or does it indicate a
problem?
Thanks.
Bill Dennis
Later,
Ricky
02 Insight
92 Saturn SC2 EV 144 Volt
Glendale, AZ USA
---------------------------------
Talk is cheap. Use Yahoo! Messenger to make PC-to-Phone calls. Great rates
starting at 1¢/min.
--- End Message ---
--- Begin Message ---
Bill Dennis [mailto:[EMAIL PROTECTED] wrote:
> Thanks to the good advice I received here, I've been able to
> use a long cord and break in my motor at 12V. The car is up
> on jack stands, and I've been running for about 8 hours now.
> I've noticed quite a bit of brown grease leaking out of the
> CV joints. Is this normal, or does it indicate a problem?
Are the axles (& CV joints) rotating as the motor is spinning?
If the jack stands are under the chassis, then the suspension will droop
and the CV joints may be operating at extreme angles and/or may be
extended outside of their normal operating range.
The axles really shouldn't be rotating in the first place, but if you
move the jack stands so that they are supporting the vehicle from the
lower control arms instead of the chassis, at least the suspension will
be in normal operating alignment.
You don't want grease leaking out of the CV joints because you need the
grease in there! ;^>
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
CV joints shouldn't leak. It's not uncommon for the boots to get old and crack.
It's usually a
simple job to regrease the joint and replace the boot. The only other reason
I've seen for leaking
is loose clamps. Whatever the cause, I would fix it. Do the joints make any
noise now? In
particular, do they make a clicking noise when you take off with the wheel
turned to one side?
Dave Cover
--- Bill Dennis <[EMAIL PROTECTED]> wrote:
> Thanks to the good advice I received here, I've been able to use a long cord
> and break in my motor at 12V. The car is up on jack stands, and I've been
> running for about 8 hours now. I've noticed quite a bit of brown grease
> leaking out of the CV joints. Is this normal, or does it indicate a
> problem?
>
> Thanks.
>
> Bill Dennis
>
>
--- End Message ---
--- Begin Message ---
Someone asked me about connecting 28 ga wire to ring terminals. Sorry I
didn't reply, I was just getting around to it and could not find the
post.
I use 1/4" ring terminals on my Hawkers. I always solder the wire after
crimping because copper oxidizes so badly in a battery box, making the
connection worse with time. If your crimp is too big then just solder
it.
Mike
Here's to the crazy ones.
The misfits.
The rebels.
The troublemakers.
The round pegs in the square holes.
The ones who see things differently
The ones that change the world!!
www.RotorDesign.com
--- End Message ---
--- Begin Message ---
ProEV wrote:
> The Li-Poly will never hit 5 volts (I hope). The range will be 2.8-4.2
> volts. Is that a problem?
No. I was just describing the circuit in terms of a 12v battery since
that voltage is of more general interest to the EV list as a whole.
> So with the Li-poly and 3.7 volts:
> I = 3.7v/max of 3.7 ohms to = > 1 amp.
Right!
>> Note that a tiny cheap 100uF capacitor probably has an intrinsic
>> ESR of a few ohms all by itself
> So just try a 100 uF capacitor and set the Fluke for inrush current
> and see what I get seems like a good plan.
Right again!
>> PS: The T9A is a really cheap, low-grade relay. Are you sure that's
>> what you want to use? They have versions that are mechanically
>> identical but with better contacts for your application.
> That is what we chose 2 years ago when we designed the relay boards.
> The T9A was priced reasonable and their pretty data sheet did not
> mention anywhere that they were 'low grade'. I wonder why not <G>?
It's about the cheapest relay you can get in this power range. That
should give you a hint :-)
> We have had four relays fail on us. Two from the 12 volt coil
> resistance going to infinity. Two from the contacts failing.
If these failures don't bother you, fine. If they do, look at the sealed
T90 series instead. They are mechanically interchangeable. Also, there
are close to a dozen brands of these relays; I've found that the Potter
& Brumfield (aka Siemens, aka Tyco) and American Zettler brands are more
reliable, and clones like the Hasco or Grigsby Barton are poor.
--
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 ---
Dave and Roger,
I don't have an RPM counter on my motor yet, so I was afraid that if I ran
the motor with the car in neutral, it might over-rev the motor. But I just
did it now, and I guess the load of the transmission itself is enough to
keep the RPMs down, since it doesn't sound like it's over-revving. I'll
continue with the rest of the break-in period with the transmission in
neutral. Then, as soon as I get the EV running, I'll take it to a shop
first thing so that they can regrease the joint. I was indeed hearing a
slight clicking sound with the transmission was in gear, so maybe I was
doing a little damage to the CV joint. I'll make sure I have it checked
once the vehicle is on the road.
Thanks for the help.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Dave Cover
Sent: Wednesday, March 29, 2006 1:45 PM
To: [email protected]
Subject: Re: Oozing Joints
CV joints shouldn't leak. It's not uncommon for the boots to get old and
crack. It's usually a
simple job to regrease the joint and replace the boot. The only other reason
I've seen for leaking
is loose clamps. Whatever the cause, I would fix it. Do the joints make any
noise now? In
particular, do they make a clicking noise when you take off with the wheel
turned to one side?
Dave Cover
--- Bill Dennis <[EMAIL PROTECTED]> wrote:
> Thanks to the good advice I received here, I've been able to use a long
cord
> and break in my motor at 12V. The car is up on jack stands, and I've been
> running for about 8 hours now. I've noticed quite a bit of brown grease
> leaking out of the CV joints. Is this normal, or does it indicate a
> problem?
>
> Thanks.
>
> Bill Dennis
>
>
--- End Message ---
--- Begin Message ---
Yes, the axels are rotating. The jack stands are under the chassis, and
that was my concern, that the angle was too sharp. I guess I should stop
the motor break-in for now.
Thanks.
Bill Dennis
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Roger Stockton
Sent: Wednesday, March 29, 2006 1:41 PM
To: [email protected]
Subject: RE: Oozing Joints
Bill Dennis [mailto:[EMAIL PROTECTED] wrote:
> Thanks to the good advice I received here, I've been able to
> use a long cord and break in my motor at 12V. The car is up
> on jack stands, and I've been running for about 8 hours now.
> I've noticed quite a bit of brown grease leaking out of the
> CV joints. Is this normal, or does it indicate a problem?
Are the axles (& CV joints) rotating as the motor is spinning?
If the jack stands are under the chassis, then the suspension will droop
and the CV joints may be operating at extreme angles and/or may be
extended outside of their normal operating range.
The axles really shouldn't be rotating in the first place, but if you
move the jack stands so that they are supporting the vehicle from the
lower control arms instead of the chassis, at least the suspension will
be in normal operating alignment.
You don't want grease leaking out of the CV joints because you need the
grease in there! ;^>
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
At 11:07 AM 29/03/06 -0600, Andre' B wrote:
Need to make a rotary switch like below, the * are contacts in a fireproof
insulating board, the O is a center pivot point. The contacts have cables
connected to them going to the indicated parts.
FIELD 1
*
FROM CONTROLLER * O * TO ARMATURE
*
FIELD 2 <etc, snipped>
Hi Andre, and all
Johns' problem is not just the 'how to' of making reverse contactors
happen, but when the motors are running in paralell at 1000A+, the motor
that (had) the reversing contact set would loaf along, whilst the other
took most of the current. Even a few mill-ohms of resistance would cause this.
If John had two controllers, one per motor, this would not be an issue,
although that would expose the motors to 300V+ pulses on startup, possibly
causing flashovers.
The 'trick' in Johns' case, is to get reverse, without adding contactors in
the main current path and unbalancing the pair of motors. The only way I
can see is to add a NiMh cell or paralell block of cells to reverse power
one field whilst powering the armature from the controller. But there must
be another way, all it takes is that "eureka" moment...
Regards
James
--- End Message ---
--- Begin Message ---
> T90 series instead. They are mechanically
> interchangeable. Also, there
> are close to a dozen brands of these relays; I've
> found that the Potter
> & Brumfield (aka Siemens, aka Tyco) and American
> Zettler brands are more
> reliable, and clones like the Hasco or Grigsby
> Barton are poor.
http://www.songchuan.com/detail1.cfm?item=30
Song Chuan makes relays for most of the vendors listed
above. (not all of their relays, just some of the
more common type like the T90, which is a SS 832A.
Rod
--- End Message ---
--- Begin Message ---
> T90 series instead. They are mechanically
> interchangeable. Also, there
> are close to a dozen brands of these relays; I've
> found that the Potter
> & Brumfield (aka Siemens, aka Tyco) and American
> Zettler brands are more
> reliable, and clones like the Hasco or Grigsby
> Barton are poor.
http://www.songchuan.com/detail1.cfm?item=30
Song Chuan makes relays for most of the vendors listed
above. (not all of their relays, just some of the
more common type like the T90, which is a SS 832A.
Typically these are lower cost than paying the extra
mark-up of the well known vendors above.
Rod
--- End Message ---
--- Begin Message ---
Mike Phillips wrote:
> My USE truck has the factory 240 to 208 step down transformer
> installed. Whenever I plug it into the 240vac outlet, the breaker
> trips. I added switches in series with each phase. When the 240 is
> turned on one phase at a time the breaker does not trip.
A large transformer draws a huge "inrush" current pulse when first
powered up; that is probably what is tripping your breaker. Household
breakers normally have a delay curve that allows a high inrush, but
perhaps your transformer is unusually large and so needs more.
> Would a series inductor keep the breaker from tripping?
Yes, if it is in series with the primary of the transformer. However,
the inrush current may be so large that it saturates the iron core of
the inductor. If this happens, its inductance goes away until the
current falls back below the point where it saturated. This is one
reason why inductors almost always have a gap in their core; it reduces
saturation.
There are other solutions. I have this inrush problem on a charger with
a big 2kw isolation transformer. Plugging this transformer directly into
a 120vac outlet trips the 15amp breaker. So, I switch the transformer to
the line with a 30amp relay. The relay's NC contact has a 10-ohm power
resistor across it, so when the relay is off, the transformer primary is
powered thru the 10-ohm resistor. This limits the peak current so the
breaker won't trip.
The 12vdc coil of this relay is powered with a little 12vdc 500ma "wall
wart" power supply. The wall wart has some large capacitor (probably
around 1000uF) inside. It takes a couple cycles of the AC line for the
wimpy transformer to charge that capacitor enough to pull in the relay.
This plus the pull-in time of the relay provides 30 msec or so for the
big transformer to precharge, so you don't get the high inrush current.
--
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 ---
Mike Phillips wrote:
> Why are wet nicad's not good with peak detecting? Isn't that a
> characteristic off all nicad/nimh? I have seen peak detectors with
> thermal sensing as well.
All nicad and nimh cells have this peaking effect (when charging at a
constant current, the cell voltage peaks at full charge, and then
falls). However, it is most pronounced with sealed nicads. The effect is
larger for nicads, and also larger for sealed cells where the internal
pressure can rise.
Flooded cells don't pressurize the cells, so there's less of a peak.
Nimh cells have less of a peak to begin with. So, detecting peak voltage
is harder, and not a reliable way to end charging. It is too easy to
miss the peak due to increasing cell temperature, or having multiple
cells in series that are all peaking at different times and so masking
the effect.
--
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 ---
On Wed, 29 Mar 2006 13:22:19 -0700, "Bill Dennis" <[EMAIL PROTECTED]>
wrote:
>Thanks to the good advice I received here, I've been able to use a long cord
>and break in my motor at 12V. The car is up on jack stands, and I've been
>running for about 8 hours now. I've noticed quite a bit of brown grease
>leaking out of the CV joints. Is this normal, or does it indicate a
>problem?
Where on the CV? Most CV joints are more or less sealed, although
I've seen some with small vent holes in the boots. From my relatively
limited experience, CVs should not ooze.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
--- End Message ---
--- Begin Message ---
James Massey [mailto:[EMAIL PROTECTED] wrote:
> Johns' problem is not just the 'how to' of making reverse
> contactors happen, but when the motors are running in paralell
> at 1000A+, the motor that (had) the reversing contact set
> would loaf along, whilst the other took most of the current.
> Even a few mill-ohms of resistance would cause this.
I think John's concern is with adding *any* additional contacts and
wires into the motor loop due to their associated losses.
As soon as the motors start spinning, the back EMF is going to make
their effective resistance great enough to make a few milliohms
difference in wiring resistance unimportant. At low RPM, where the
effective motor resistance is lowest, the motors are in series, so the
current through both motors is forced to be equal anyway. A few
additional milliohms in series with the motors is simply going to cause
the series/parallel shift to occur slightly earlier (1V per milliohm
earlier at 1000A motor loop current).
If a 170V motor limit is enforced in series mode (ie. 170V total,
assuming the 'Zilla doesn't differentiate between series and parallel
when enforcing this limit), then the effective motor resistance is about
170 milliohms when the current has dropped to 1000A and the shift to
parallel occurs. This means each motor represents about 85 milliohms,
so a few milliohms additional resistance in series with one of them
would result in a few % difference in the current through the two
motors. If the 'Zilla actually doubles the motor voltage limit in
series mode to account for the voltage being divided across 2 motors,
then the effective motor resistance is actually 2x this at the shift
point.
Look at it this way; Matt's car is running the same controller as
John's, and a pair of 9" motors, and he is getting *very* respectable
performance (perhaps even better than John's when you factor in vehicle
weight) even though he does have a reversing contactor in the motor
loop.
My concern would be that a reversing contactor relies on current flowing
though the NC and NO contacts depending on the direction selected, and
usually NC contacts are rated for less current than the NO set. I would
think that wiring the reversing contactor so that it must be energised
for forward "gear" so that the NO contacts carry the heavy race current
would be a good thing to do.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
On Wed, 29 Mar 2006 12:01:35 -0600, Lee Hart <[EMAIL PROTECTED]>
wrote:
>My ComutaVan never topped 25 amps on the 12v system, though I didn't
>have a radio and replaced the stock gasoline heater.
>
>If you're going to power the DC/DC with its own 12v battery, all you
>really need is a DC/DC with about a 3v high-current isolated output.
>Connect this output in series with the 12v battery, and adjust it to get
>the desired system voltage. For instance, if you want 14v, adjust the
>DC/DC output to 20; 12v + 2v = 14v. This way, your DC/DC is far smaller,
>cheaper, and more efficient.
>
>But, it's more normal to run the DC off the main propulsion pack, and
>then downsize or even eliminate the 12v accessory battery.
I chose a little different approach on my CitiCar based on cost and
convenience. I've converted mine to electronic controller and 72
volts so I didn't have to worry about the split pack.
My Citi peaks at about 25 amps with all the lights and accessories on.
I did not want to spend the big bux on a 25 amp converter so I
installed a smaller 12 volt battery (two 17ah Hawker Genesis in
parallel - what I had on hand) and a lower current (10 amp) converter.
My rational is that since the car can only operate a little under an
hour per main pack charge, the 34ah of Hawkers supplemented by the
converter will do the job.
Also entering into this equation is the cost of a 12 volt charger if
one is used. I decided to use the DC/DC converter to charge the
Hawkers. Since the full 25 amp load is rarely seen and the more
normal daylight load is under 10 amps, the DC/DC does that job fine.
I used an Astrodyne SD-100, suffix C converter. This converter is
rated at 100 watts nom (it easily does 140 watts, 14 volts at 10 amps)
with a 72 volt nom input. This is a semi-open frame converter so it
has to be located in the dry.
It is connected directly to the pack through the appropriate
switch/breaker and operates all the time including main pack charging.
I made a minor modification (reed relay and resistor) to jack the
voltage from 13.2 to 14 volts when the ignition is on. This gives me
brighter lights and keeps the Hawkers more fully charged.
My next step is going to be to add a Progressive Dynamics Charge
Wizard (about $20) to turn the converter into a smart multi-stage
charger. After that mod is done the DC/DC will smart-charge the 12
volt pack whenever needed, either from the main pack or from the main
pack charger.
This has worked out extremely well. My headlights are nice and bright
at night and the Hawkers remain fully charged most of the time.
As Lee noted, for anything higher than 72 volts, it's generally
cheaper to use a pure switchmode power supply (SMPS) operated from the
pack voltage. DC/DC converters are available for higher voltages but
they seem to be VERY expensive.
Most pure SMPS's will operate on DC in. I know that Astrodyne's will
and others have reported that some Lambdas will. A call to the
support line will confirm which models work OK.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
A foolish consistency is the hobgoblin of little minds.-Ralph Waldo Emerson
--- End Message ---
--- Begin Message ---
Oh dear I'm sorry that you feel that this is some sort of fight with winners
and losers.
I only bring my thoughts, feelings and personal experience to the list to
try and help others make their decisions and hope that when I have a
question then others share their experiences and techniques with me and the
rest of our "brotherhood" of EV enthusiasts.
John
----- Original Message -----
From: "Philippe Borges" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, March 29, 2006 7:25 PM
Subject: Re: STM5-100
you win :^)
cordialement,
Philippe
Et si le pot d'échappement sortait au centre du volant ?
quel carburant choisiriez-vous ?
http://vehiculeselectriques.free.fr
Forum de discussion sur les véhicules électriques
http://vehiculeselectriques.free.fr/Forum/index.php
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, March 29, 2006 9:12 AM
Subject: Re: STM5-100
>>> Philippe says the care regime is probably the cause of early failure
in the
Nicads. - So come on Philippe "spill the beans" what should we be doing
that the
manufacturer of the EV is not doing in the service routine and how can us
enthusiastic owners do this properly without wasting our hard earned
dollars.
<<<
I'm only guessing here, but what about watering more often?
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--- End Message ---
--- Begin Message ---
Well that was quick...
But no replys on the EV list.
Jim, John, and other maybe confused EV listers...
This post does not Say John Can't make 772 Ft lbs of torque..
In Fact the purpose of this post was to define where he CAN make that
Monster amount of Twist..
So relax Jim.... I have just said where it can be done....
It only takes 95 volts on the motors to make 772 ft lbs. Or about 48 across
each motor...
This is a far cry from the 348 that a cursory glance Seams to show.
So lets keep in mind that a Quoted... motor performace Spec ...needs to have
the motor Volts and Amps and Torque at a given RPM.
All else is Sales propaganda.
By the way it looks like a the lowest voltage to needed to make 2000 amps
flow in each motor is about 10 volts. So with a Current limited controller,
You can keep the torque at 772 ftlbs across twin motors from about 20 volts
to just over 90 volts.
John Said that the initial launches on hot batteries ...sages to only 220s.
So.. he can pull harder for longer that the first simulation.
Adding taller gears will allow him to pull even longer... but with abit less
acceleration for the same motor Torque.
Did I clear this up at all????
I hope so.
Madman
----- Original Message -----
From: "Rich Rudman" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Wednesday, March 29, 2006 10:56 AM
Subject: Re: DC Motors for Racing (and Matt's Nissan 200SX)
> Hey Jim...
> And other Bench Racing EV Racers...
>
> The Quote of 772 ftlbs of torque and 348 volts is clearly a Bogus
number...
>
> John, Jim and others... It should real with 348 volts of Battery, he made
> 772 Ftlbs of torque.....
> There is NOW way that he had 348 volts on the motor... Can't happen....
> Battery Sag, motor brush arcing...... this can't happen the motor would
> disspear in a ball of Arcing vaporizing copper.
>
> The only Ev Racer that has a chance of living with over 300 volts on the
> motor is Dennis Burbe's modified for racing with his secret Brush
compounds.
>
> Wayland's Warp 8 and my Warp 8 have to be proteced with the Zilla by
> limiting our motor voltage to less than 170 volts in parallel and less
than
> 340 in Series. Our basicly stock Commutations and brush compunds, simpley
> are not up to more voltage. Nice... but we have a LOT to learn about
keeping
> the Arcs down.
>
> What DOES happen on the White Zombie, and Ot's 914 and My Fiero and Matt's
> twin 9s is... the controller lets a programmed motor current fly as long
as
> the motor voltage limts are NOT active.
> So... at the starting line you might have 2000 amps and say 20 to 60
volts,
> This varies from a hand full of volts at maximum amps Where the Max amp
can
> not be supported by the power coming from the batteries, This is the
Current
> limited launch that We need to keep the tires on the ground does. Once the
> Battery amps and volts fall to the point where the motors see what ever
the
> Lead can supply, Then it's time to shift, or wait a long time for the amps
> to fall to 1/2 the peak before lighting off the parallel switch event.
>
> So... you only have 772 Lbs Ft of torque flowing to the rear end.... when
> you have 2000 amps flowing in the motors. And only this can happen in
series
> mode, and only when the motors are not spinning fast enough to have much
> BACK EMF.
>
> The real data point is more like at 1/2 pack voltage you have 174 volts on
> the batteries, making 1100 motor amps... John's self imposed battery limit
> At 174 volts The motors can't pull more than say 2000 amps and at less
than
> 2500 Rpm...in series they can't. I really need a motor chart for this...
> So..The max Torque can only be made from zero Speed to about 40 miles per
> hour.
> There are other factors tha would make this number even lower... But I
don't
> have them.
>
> The Best Guess is the peak motor torque , happens at less than 95.7 motor
> volts. This should be the point where the Zilla comes off of 2000 motor
> amps. Asuming a perfect Buck conversion in the Zilla.
> This is less than the 170 volts self imposed Limit on non modified motors
> and brush rigging and brush compunds.
> Yes Campers... Plasma Boy could use more controller.
>
> Rich Rudman
> Manzanita Micro
>
>
>
> ----- Original Message -----
> From: "Jim Husted" <[EMAIL PROTECTED]>
> To: <[email protected]>
> Sent: Monday, March 27, 2006 3:39 PM
> Subject: RE: DC Motors for Racing (and Matt's Nissan 200SX)
>
>
> Hey Rodger, all
>
> I just called Wayland and he informed me that Joe Smalley did the
> calulations based off his 60 foot times, weight of the car and amperage,
> ect. I'm sure John can add details here. I agree with you in that
> collecting the data is a hard thing to get. Many of my mods are still
> untested and it makes me crazy as I wait for the numbers to be reported.
> BTW remember that it's been a pretty hard winter here this year and
Wayland
> like the rest of us works hard, long hours paying the bills so it takes
time
> to put together a trip to the dyno not to mention other EVents. I'm sure
> John will pipe in here tonight (he's coming over the mountain tonight as a
> matter of fact and I'll be having dinner with him (so I'll get to prod him
> here, hehe)
> Hope this helps
> Jim Husted
> Hi-Torque Electric
>
> Roger Stockton <[EMAIL PROTECTED]> wrote:
> Jim Husted [mailto:[EMAIL PROTECTED] wrote:
>
> > Well I know John Waylands Siamese8 setup runs 772 ft. lbs.
> > @ 348 volts.
>
> Hey Jim, how do you know this? Did John finally get the 'Zombie onto a
> dyno like he's been hoping to on and off for the last year or more? Or,
> did you guys dyno the motor on its own?
>
> Either way, is there any more real data available; torque vs RPM curves,
> etc.? Data like this is hard to come by for racing level voltages and
> currents...
>
> Cheers,
>
> Roger.
>
>
>
>
> ---------------------------------
> Blab-away for as little as 1¢/min. Make PC-to-Phone Calls using Yahoo!
> Messenger with Voice.
>
--- End Message ---
--- Begin Message ---
Rich Rudman [mailto:[EMAIL PROTECTED] wrote:
> Well that was quick...
>
> But no replys on the EV list.
I didn't think any was required; what you wrote seemed clear enough to
me.
Joe has estimated the torque based on physics, not motor ft-lbs/amp
estimates, etc., so he is probably in the ballpark. 350-400 ft-lbs from
each of the 8" motors at 2000A sounds reasonable based on prior
discussions.
If Joe has accelerometer data synchronised to the 'Zilla
voltage/current/rpm data log, then perhaps he can actually derive
estimated curves relative to voltage and current; if not, it seems we'll
just have to wait for John to have a chance to get the 'Zombie on a
dyno.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Forgive me if this winds up being newbie stupidity but it seems like all of
you are over-complicating this whole issue.
The need seems to be:
-having reverse for the occasional time when he will need to back up. These
occasions most likely would need to reverse only slowly for 10-30 feet max
to turn around, etc...
Why do you need to use the Zilla at all? Do you even need to drive both
motors at the same time?
Seems to me it would be much simpler to just put in a completely separate
controller to handle reverse to one motor. You could use the smallest
controller and wiring adequate for the job (Alltrax/Curtis and small wires?)
and it would only need to run in one direction (reverse).
You could tie it in to just part of the HV pack (to get a lower voltage)
because the power requirements to move 30 feet would be so small that I
wouldn't think the Hawkers would even know.
While I'm throwing out crazy ideas why not make it easily removable
(everything attached to a board except the small wiring) that way you could
take it out when you get to the track when the minimal weight of it would
still be important.
I may be completely missing something here of course.
Jay (Non-EE perspective)
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Roger Stockton
Sent: Wednesday, March 29, 2006 4:20 PM
To: [email protected]
Subject: RE: Fast Street Car with Twin DC Motors
James Massey [mailto:[EMAIL PROTECTED] wrote:
> Johns' problem is not just the 'how to' of making reverse
> contactors happen, but when the motors are running in paralell
> at 1000A+, the motor that (had) the reversing contact set
> would loaf along, whilst the other took most of the current.
> Even a few mill-ohms of resistance would cause this.
I think John's concern is with adding *any* additional contacts and
wires into the motor loop due to their associated losses.
As soon as the motors start spinning, the back EMF is going to make
their effective resistance great enough to make a few milliohms
difference in wiring resistance unimportant. At low RPM, where the
effective motor resistance is lowest, the motors are in series, so the
current through both motors is forced to be equal anyway. A few
additional milliohms in series with the motors is simply going to cause
the series/parallel shift to occur slightly earlier (1V per milliohm
earlier at 1000A motor loop current).
If a 170V motor limit is enforced in series mode (ie. 170V total,
assuming the 'Zilla doesn't differentiate between series and parallel
when enforcing this limit), then the effective motor resistance is about
170 milliohms when the current has dropped to 1000A and the shift to
parallel occurs. This means each motor represents about 85 milliohms,
so a few milliohms additional resistance in series with one of them
would result in a few % difference in the current through the two
motors. If the 'Zilla actually doubles the motor voltage limit in
series mode to account for the voltage being divided across 2 motors,
then the effective motor resistance is actually 2x this at the shift
point.
Look at it this way; Matt's car is running the same controller as
John's, and a pair of 9" motors, and he is getting *very* respectable
performance (perhaps even better than John's when you factor in vehicle
weight) even though he does have a reversing contactor in the motor
loop.
My concern would be that a reversing contactor relies on current flowing
though the NC and NO contacts depending on the direction selected, and
usually NC contacts are rated for less current than the NO set. I would
think that wiring the reversing contactor so that it must be energised
for forward "gear" so that the NO contacts carry the heavy race current
would be a good thing to do.
Cheers,
Roger.
--- End Message ---
--- Begin Message ---
Steve Gibbs wrote:
> [Electronic Design] magazine has a schematic for a relatively simple
> battery charger based on high and low voltage thresholds.
This circuit is too crude to bother with. It's just a
transformer-rectifier charger with a relay to switch it on/off at two
poorly-defined voltage thresholds.
There are many equally-simple circuits that work better. One is the
two-SCR circuit that GE published back around 1970 and has been used in
millions of inexpensive chargers. Here's the version used in the CitiCar
48vdc 25amp charger:
__
________________|\|________________/ \___48vdc
| _|_ |/|\ | \__/ pack+
| "full / \ I1 | D2 SCR | ammeter
| charge"\___/ #47 | GE C38A |
D1 bridge | lamp | 6.3v | 100v,35a |
100v,35a __|__ R1 > 0.15a | |
| + | 47 > | R3 |
___ ___|AC | 1w > | 1k |
_| || |_ | | |___|\|___|___/\/\___|
_| || |_ | | | |/| |
_| || |_ | | R2 > D3 1N4004 > R4
___| || |___| | 470 > 400v,1a > 20k
|AC | 5w > >
T1 |__-__| | D4 zener |
pri: 120vac | _|_ 1N4742A > R5
sec: 48vac,25a | _\_/_ 12v,1w / -->> 5000
| D5 SCR | \______|\|_____| >
| C106A | | |/| | |
| 100v,4a | > / C1+_|_ > R6
| | R7 > 47uF ___ > 5600
| | 1k > 25vdc | >
|__________|_____|__________|___|________48vdc
pack-
This circuit uses an SCR instead of a relay; the SCR won't wear out from
switching on/off. It also has a zener diode, which provides a much more
precise voltage threshold than the transistor base-emitter junction.
Otherwise, it works the same; it charges at full power until the battery
reaches a threshold voltage (set by R5). Then it cycles on/off to hold
the battery at this voltage. If R5 is set to a good float voltage, this
charger can be left on indefinitely, but will take well over 24 hours to
reach "full". If set for a higher voltage, it reaches "full" sooner, but
will overcharge if left on.
--
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 ---
