EV Digest 4470
Topics covered in this issue include:
1) Re: Rolling Resistance
by Victor Tikhonov <[EMAIL PROTECTED]>
2) Re: PCF-20 Design Flaw
by "Rich Rudman" <[EMAIL PROTECTED]>
3) Re: Another PFC Caution? (was: PDF-20 design flaw) (long)
by "Rich Rudman" <[EMAIL PROTECTED]>
4) Re: Letting the smoke out , DCP
by "Rich Rudman" <[EMAIL PROTECTED]>
5) Re: Letting the smoke out , DCP
by Bob Bath <[EMAIL PROTECTED]>
6) Re: Another PFC Caution? (was: PDF-20 design flaw) (long)
by Victor Tikhonov <[EMAIL PROTECTED]>
7) Re: 9" Motor questions
by "Paul G." <[EMAIL PROTECTED]>
8) Re: Another PFC Caution?
by Victor Tikhonov <[EMAIL PROTECTED]>
9) RE: Another PFC Caution? (was: PDF-20 design flaw) (long)
by "Chris Tromley" <[EMAIL PROTECTED]>
10) Re: Another PFC Caution? (was: PDF-20 design flaw) (long)
by "Rich Rudman" <[EMAIL PROTECTED]>
11) RE: Another PFC Caution? comments .
by "Chris Tromley" <[EMAIL PROTECTED]>
12) Re: Vas: Re: discontinued Siemens motors
by Victor Tikhonov <[EMAIL PROTECTED]>
13) How much weight might this support?
by Ryan Stotts <[EMAIL PROTECTED]>
14) adapting MES motor (was: discontinued Siemens motors)
by "Charles Whalen" <[EMAIL PROTECTED]>
15) Re: BRUSA NLG5xx max voltage
by Michael Hurley <[EMAIL PROTECTED]>
--- Begin Message ---
Yes and no
That is correct as far as tires go (tranny disengaged),
but if you spin the oil in the gear box, of course higher speeds
result in higher drag from it.
Your simulator must take into account all major sources of drag
(unless it is very primitive, which is still OK for guestimations,
or other unknowns mask off this inaccuracy anyway).
I usually set it to fixed 0.01 value
--
Victor
'91 ACRX - something different
Don Cameron wrote:
A few friends and I were reviewing the performance simulations and noticed
that in a number of models that rolling resistance did not vary with speed -
is this correct?
thanks
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
--- End Message ---
--- Begin Message ---
Bill I am Glad you think I am taking this seriously...
I wish you did last fall when you started using your PFC20 charger on your
NiCds.
The total time on charge does what you want it to. But needs about 5x the
time frame.
You will note that the SAFT booklet DOES give a constant current time
limited curve.
You did not ask how to implement this. I found that a bit funny at the
time.
And now we have a real problem in how you think Lead Acid really charges.
Keep in mind I have a few years of charging AGM lead acid.... Just a few
like 15 years.
PbLas CAN go into thermal runaway.... But Very unlikely with a properly set
voltage limit. I have NEVER had or let my Optimas go into runaway, With
hours of 14.8 volts on them. READ days and no dropping voltages and run away
currents. The only folks that have had runaways are Flooded and Gell users.
They had the finish voltage set very high, like 15.6, had 100 plus Deg
ambient and had run them very hard on the last cycle. Well what do you
expect???
Lead acids basically don't go into thermal run a way unless you abuse them.
NiCads on the other hand will, And the manufacture clearly tells you this.
They tell you to limit the over charge and give specific percentages of
amphours over that which has been taken out. They also lay down a
temperature limit and a maximum current and time.
My gear limits a time at the set peak voltage. Nothing more. If the battery
does not stay at that voltage the charger keeps on doing it's thing. This
clearly is inadequate for hands off NiCad charging.
As you have shown with a deft hand you can get it to work %99.9 percent of
the time. How many safe charge cycles did you get for two "Events"? A few
hundred??? More???
Don't tell me and the List that Lead Acids make excessive amounts of heat
when charging...Most of us know exactly how hot our packs get when doing a
correct charge. Packs I have used and tested have about a 10 to 20 Deg F
rise. This is not a cause for alarm unless the Lead is already at 110 Deg F
or higher. So.. the lead acid pack thermal runaway potential cal be almost
ignored unless you have a 100 Deg Battery to start with.
I have purposely driven a Optima Red top into thermal runaway for racing
purposes, it took 17 plus volts and 20 amps and about 2 hours in the
Phoenix sun with a air temp of over 90 deg F to get this to happen. So... it
takes some effort to get a AGM to take off. Dave Cloud and I did this for
the APS race in '96, You were there also.
Ni cads on the other hand.... are totally different, you can accurately use
the rise in case temp to determine when to end the constant voltage phase.
The rule of Thumb is a 5 Deg rise in 15 minutes or faster is
the cut off. So on Every cycle they go into some form of thermal run away.
If they don't you are not charging them hard enough or long enough.
So Bill in addition to your AC line timer you really should have a Delta
Temp detector....Or just terminate the charge if the NiCads get over 110 Deg
F.
Are we finally getting to the details that I assumed your level of training
prepared you for??
Rich Rudman
Manzanita Micro
--- End Message ---
--- Begin Message ---
No load power up.
It's a switcher... If it cycles ... and there's no place for the juice to
go. BANG! We have just enough caps on the DC side to keep it alive.
Clearly at times this is not enough.
It was most likely damaged while doing your Dc/DC testing.. and then died at
a later date.
The quick breaker trip was a sure sign that something really Bad was taking
place. Like your ouput was grounded to the case of the charger. You got a
shoot through from the charger's output to the AC grid. In effect it was
shorted out to AC grid.
Then once things are hurt it's just a matter of time before the damage
really causes a fail.
Yes it's protected... about 3 ways from Sunday. And this is not enough.
The Iso units will have a much greater safety margin with this kind of
inadvertant damage.
We hope. Well it's supposed to work that way...
So for all swticher power supplies... always set the current to Zero before
turning them on, and always have some kind of load attached to the output.
Even a light builb helps.
Or just don't power them up until you have them installed and wired to the
pack.
The first sheet on the shipped manual has all the don't and DO NOTs on it.
Reading might help.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Chris Tromley" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, July 01, 2005 7:24 AM
Subject: Another PFC Caution? (was: PDF-20 design flaw) (long)
> Stuff like this makes an electrical idiot like me just go freakin' nuts.
> Most on the list are pretty savvy regarding this stuff. Electrical
> understanding allows them to cope with the non-"consumer-grade" hardware
we
> must necessarily use sometimes. But people like me can run into some
> expensive surprises. I have my own story to add (below). (I need to
> apologize in advance for posting this just before a long weekend.
Responses
> will have to wait until my return.)
>
> Let me state clearly that I am very grateful that Rich makes the PFC
> chargers. He and Joe have created an extremely flexible, compact and
> powerful product at a good price. Rich takes the quality of his product
> very personally. This is all a Very Good Thing.
>
> It is also true that his is a small operation that is (almost by
definition)
> short on resources. That means the product offering could be better in
some
> ways, but that is certainly not meant to disparage anyone's efforts. Just
a
> statement of fact that should be understood. The key to making it work is
> letting people know the problems and work-arounds.
>
> A good example is isolation. As has been discussed frequently, the PFC
> series chargers (except for an as-yet-unreleased model?) are not isolated.
> Some see that as a problem, some don't. The important thing is that it is
> *known*, so those who see it as a problem can deal with it accordingly. I
> have an off-board isolation transformer for use at home. Others deal with
> it, or don't, as they see fit.
>
> Bill Dube' wrote:
>
> > >I assumed you knew this [possibility of thermal runaway] about Ni Cads
I
> do and So does Joe. It was a
> > matter
> > >of asking.
> >
> > Lead-acid does exactly the same thing. (Only worse.) During the
> > constant-voltage stage, the batteries really get warm. As they warm up,
> > the
> > voltage goes down. As the voltage goes down, the current goes up. As the
> > current goes up, the batteries get REALLY warm. Then, if they get hot
> > enough, the voltage dips below the trigger voltage and the timer resets.
A
> > few hours later, the plastic on the cases will start to melt.
>
> Whether or not Bill "should" have dealt with his NiCds in a certain way is
> immaterial to me. I see the very real potential here for a thermal
runaway
> in my flooded lead-acid pack. Sure, it's a rare occurrence in general,
but
> *it happens*. And apparently the current PFC chargers will *allow* it to
> happen. Sorry Rich, this sounds like an "oops". I have to agree that it
is
> a design flaw. (I'm a development engineer myself. Trust me, I've
> committed my share. It's unavoidable - some will slip through.) Thanks
for
> recognizing that it needs to be fixed and letting us know it will be.
>
> I happen to like the timer-start-on-constant-voltage feature, so I will
> continue to use it and add an external timer to the power cord. That's a
> bit of a kludge, but I feel it's necessary to provide the level of
> investment protection that's acceptable to me. Make no mistake - if I
> toasted a $1500 pack with a thermal runaway when the charger *could* have
> easily stopped it and *didn't*, I'd be Very Angry. I can only imagine how
> Bill feels about his $10k pack. I have no idea what should have been
> assumed or not in his case. Now that I know the issue exists, I can deal
> with it.
>
> Now for my personal experience. Since I'm unqualified, I present this
here
> to let those more knowledgeable than me decide whether it's a flaw. To
me,
> it at least needs to be made known so others can deal with it.
>
> I (naively) attempted to make a DC/DC converter out of a Vicor BatMod.
> Probably a piece of cake for most, but I had problems. (The Vicor modules
> are quite good, but need external circuitry to make them a
fully-functional
> DC/DC converter.) My attempt failed on my car, so I brought it into work
to
> test and fix. We didn't have a 120 VDC source at work, so I brought in my
> PFC-20. The EE who was helping me said it should work fine. (I should
> state here that he is quite capable but specializes in instrumentation,
not
> power electronics.)
>
> We hook it all up and flip the breaker on the PFC, the breaker immediately
> snaps off hard. Try again, same thing. EE scratches his head. Work on
my
> DC/DC stops.
>
> Some time later, I'm charging my pack and the voltage falls back to its
> uncharged level. No twiddling of dials or pots will get it to put
anything
> out, even to a 12V battery. The power stage is dead. A $200 rebuild,
plus
> $100 for two-way shipping.
>
> My understanding, which may not be clear, is that the PFC chargers are
quite
> sensitive to being powered with no load. That is not something that is
> mentioned in the manuals, and apparently is not something that even an EE
> would expect. As one EVDL member mentioned, a disconnected wire or any
> fault that blows the output fuse could cause an expensive 2 week repair.
> (That was mostly shipping time - Rich turned it around quickly).
>
> Rich and others, for the sake of all please verify that my take on this is
> fair, or correct me if necessary. We are all in a sense early-adopters
> simply by virtue of being involved with home-built EVs, and must accept
the
> occasional glitch. The flip side is that we all *need* any information
that
> is available to avoid unnecessary problems.
>
> I have tremendous respect for Rich, Joe, Otmar and all the others who ride
> the bleeding edge of product development. It can be a rough ride. They
are
> doing a tremendous amount with surprisingly little. Having written my
share
> of manuals I know how much time good documentation can suck up. I also
> think it's absolutely critical that known issues be made known *to all* in
> some way, this list being a good start. That's the only way we can turn
> this hobby into a transportation paradigm instead of continually tripping
> over ourselves.
>
> I think there are few here who would see a discussion of a problem and
> work-around as an indication of poor quality. I think it would more
likely
> be seen as commendably pro-active customer support. So what's the story
on
> no-load power up?
>
> Chris
>
>
--- End Message ---
--- Begin Message ---
Unfortunatley... I can back this story up.....
Rich Rudman
Manzanita Micro
EX VP and founder of DCP.
I can't say good enough things about My Zilla 2K.
Or the early hand built DCPs that I was proud to be a part of.
Back to building chargers Ever tougher ever stronger...
----- Original Message -----
From: "Brian D.Hall" <[EMAIL PROTECTED]>
To: "ev post" <[email protected]>
Sent: Friday, July 01, 2005 9:29 AM
Subject: Letting the smoke out , DCP
> Just a short note of Warning to folks that are working with the new owner
of
> DCP, He gives no warranty for his work. I sent him a working t-rex
belonging
> to a customer that had a ground fault through the precharge circuit,
> returning the unit for over double the quoted price it still had the same
> problem. He then stated that it was normal and Okay to use. It only lasted
> about 5 miles , glad no one was hurt , I have had these go full on when
they
> blow. Customer now has his EV grin back with a Zilla 1K.
>
> Brian D. Hall
> [EMAIL PROTECTED]
>
--- End Message ---
--- Begin Message ---
Clarification:
--- "Brian D.Hall" <[EMAIL PROTECTED]>
wrote:
> Just a short note of Warning to folks that are
> working with the new owner of
> DCP,
Let's be specific. There is no "new owner" that I
know of. Peter Senkowski has DCP/AllTrax run a new
version of the on-road controllers, and has updated
the circuitry. He provides the new and refurb'd units
with a 1-year warranty. Or perhaps there has been
some other arrangement that I'm not privy to, and
that's what you're referring to...
He gives no warranty for his work. I sent him a
> working t-rex belonging
> to a customer that had a ground fault through the
> precharge circuit,
> returning the unit for over double the quoted price
> it still had the same
> problem. He then stated that it was normal and Okay
> to use. It only lasted
> about 5 miles , glad no one was hurt , I have had
> these go full on when they
> blow.
For the record, all DC controllers have the ability to
fail in a full-on mode. That's why we are supposed to
be building them with fuses and circuit breakers; the
latter accessible from the cabin of the vehicle.
Just my 0.02 (;-p
'92 Honda Civic sedan, 144V
____
__/__|__\ __
=D-------/ - - \
'O'-----'O'-'
Would you still drive your car if the tailpipe came out of the steering wheel?
Are you saving any gas for your kids?
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
I must say if I see the manual where known issues are listed
and work arounds (if exist) are offered, the vendor earns
extra respect as being honest. Hiding *known* shortcomings so
the product looks perfect and flawless is always suspicios.
Most respected IC manufacturers always issua errata
sheets. IT is public admittion of the error, but the
customer's benefit of knowing about it outweigh somewhat
bad taste that the resourceful manufacturer could not get
it right in the first place.
Of course, unknown problems are different, they have to
be recognized and listened to with interest to fix it.
Even if it ain't broken, it has to be explained, then
everyone is prepared, means happy.
--
Victor
'91 ACRX - something different
Victor
Chris Tromley wrote:
Stuff like this makes an electrical idiot like me just go freakin' nuts.
Most on the list are pretty savvy regarding this stuff. Electrical
understanding allows them to cope with the non-"consumer-grade" hardware we
must necessarily use sometimes. But people like me can run into some
expensive surprises. I have my own story to add (below). (I need to
apologize in advance for posting this just before a long weekend. Responses
will have to wait until my return.)
Let me state clearly that I am very grateful that Rich makes the PFC
chargers. He and Joe have created an extremely flexible, compact and
powerful product at a good price. Rich takes the quality of his product
very personally. This is all a Very Good Thing.
It is also true that his is a small operation that is (almost by definition)
short on resources. That means the product offering could be better in some
ways, but that is certainly not meant to disparage anyone's efforts. Just a
statement of fact that should be understood. The key to making it work is
letting people know the problems and work-arounds.
A good example is isolation. As has been discussed frequently, the PFC
series chargers (except for an as-yet-unreleased model?) are not isolated.
Some see that as a problem, some don't. The important thing is that it is
*known*, so those who see it as a problem can deal with it accordingly. I
have an off-board isolation transformer for use at home. Others deal with
it, or don't, as they see fit.
Bill Dube' wrote:
I assumed you knew this [possibility of thermal runaway] about Ni Cads I
do and So does Joe. It was a
matter
of asking.
Lead-acid does exactly the same thing. (Only worse.) During the
constant-voltage stage, the batteries really get warm. As they warm up,
the
voltage goes down. As the voltage goes down, the current goes up. As the
current goes up, the batteries get REALLY warm. Then, if they get hot
enough, the voltage dips below the trigger voltage and the timer resets. A
few hours later, the plastic on the cases will start to melt.
Whether or not Bill "should" have dealt with his NiCds in a certain way is
immaterial to me. I see the very real potential here for a thermal runaway
in my flooded lead-acid pack. Sure, it's a rare occurrence in general, but
*it happens*. And apparently the current PFC chargers will *allow* it to
happen. Sorry Rich, this sounds like an "oops". I have to agree that it is
a design flaw. (I'm a development engineer myself. Trust me, I've
committed my share. It's unavoidable - some will slip through.) Thanks for
recognizing that it needs to be fixed and letting us know it will be.
I happen to like the timer-start-on-constant-voltage feature, so I will
continue to use it and add an external timer to the power cord. That's a
bit of a kludge, but I feel it's necessary to provide the level of
investment protection that's acceptable to me. Make no mistake - if I
toasted a $1500 pack with a thermal runaway when the charger *could* have
easily stopped it and *didn't*, I'd be Very Angry. I can only imagine how
Bill feels about his $10k pack. I have no idea what should have been
assumed or not in his case. Now that I know the issue exists, I can deal
with it.
Now for my personal experience. Since I'm unqualified, I present this here
to let those more knowledgeable than me decide whether it's a flaw. To me,
it at least needs to be made known so others can deal with it.
I (naively) attempted to make a DC/DC converter out of a Vicor BatMod.
Probably a piece of cake for most, but I had problems. (The Vicor modules
are quite good, but need external circuitry to make them a fully-functional
DC/DC converter.) My attempt failed on my car, so I brought it into work to
test and fix. We didn't have a 120 VDC source at work, so I brought in my
PFC-20. The EE who was helping me said it should work fine. (I should
state here that he is quite capable but specializes in instrumentation, not
power electronics.)
We hook it all up and flip the breaker on the PFC, the breaker immediately
snaps off hard. Try again, same thing. EE scratches his head. Work on my
DC/DC stops.
Some time later, I'm charging my pack and the voltage falls back to its
uncharged level. No twiddling of dials or pots will get it to put anything
out, even to a 12V battery. The power stage is dead. A $200 rebuild, plus
$100 for two-way shipping.
My understanding, which may not be clear, is that the PFC chargers are quite
sensitive to being powered with no load. That is not something that is
mentioned in the manuals, and apparently is not something that even an EE
would expect. As one EVDL member mentioned, a disconnected wire or any
fault that blows the output fuse could cause an expensive 2 week repair.
(That was mostly shipping time - Rich turned it around quickly).
Rich and others, for the sake of all please verify that my take on this is
fair, or correct me if necessary. We are all in a sense early-adopters
simply by virtue of being involved with home-built EVs, and must accept the
occasional glitch. The flip side is that we all *need* any information that
is available to avoid unnecessary problems.
I have tremendous respect for Rich, Joe, Otmar and all the others who ride
the bleeding edge of product development. It can be a rough ride. They are
doing a tremendous amount with surprisingly little. Having written my share
of manuals I know how much time good documentation can suck up. I also
think it's absolutely critical that known issues be made known *to all* in
some way, this list being a good start. That's the only way we can turn
this hobby into a transportation paradigm instead of continually tripping
over ourselves.
I think there are few here who would see a discussion of a problem and
work-around as an indication of poor quality. I think it would more likely
be seen as commendably pro-active customer support. So what's the story on
no-load power up?
Chris
--- End Message ---
--- Begin Message ---
On Jun 30, 2005, at 12:44 PM, Rush wrote:
1) If I rotate the motor clamp so that the flat plate is on the
bottom, fabricate an adapter mount plate that the flat plate sits on
and attaches to, can I then attach the adapter mount plate directly to
the holes of the existing motor mounts or do I have to use the rubber
bushings as shock absorbers?
I recommend that you do. If you have a rubber mounted tranny and a
solid mounted motor the motor mount will take the torque reaction
first. Its a good way to twist the clamshell motor mount on the motor.
Paul "neon" G.
--- End Message ---
--- Begin Message ---
Usually equipment not tolerating no load very well has minimum
load built into them to keep them from blowing up in such
situations. It wastes power all the time (say, power resistor
or 5-10W light bulb as "on" indicator), but the solution
still may worth it. Some DC-DCs have min load a customer
cannot disconnect
Ryan Stotts wrote:
Chris Tromley wrote:
My understanding, which may not be clear, is that the PFC chargers are quite
sensitive to being powered with no load.
Are you saying if I plug in the charger and turn it on without it
being connected to anything, it will blow the power stage?
That is not something that is mentioned in the manuals, and
apparently is not >something that even an EE would expect.
It needs to be for at least two reasons: Someone might plug it in and
turn it on just to see if the charger works.. Someone might power it
up without it being connected to the battery pack to adjust the
settings beforehand..
--
Victor
'91 ACRX - something different
--- End Message ---
--- Begin Message ---
Ryan Stotts wrote:
> Chris Tromley wrote:
>
> > My understanding, which may not be clear, is that the PFC chargers are
> quite
> > sensitive to being powered with no load.
>
> Are you saying if I plug in the charger and turn it on without it
> being connected to anything, it will blow the power stage?
>
> >That is not something that is mentioned in the manuals, and
> apparently is not >something that even an EE would expect.
>
> It needs to be for at least two reasons: Someone might plug it in and
> turn it on just to see if the charger works.. Someone might power it
> up without it being connected to the battery pack to adjust the
> settings beforehand..
Hi Ryan,
That was my understanding after some correspondence with Rich. Not
necessarily that it *will* blow the power stage, but that you're really
begging for trouble by doing this. Again, I'm no expert and this is from
memory. Rich or Joe need to answer this.
Chris
--- End Message ---
--- Begin Message ---
Both of which you should not do.
Your risk of it coming unglued depends on a LOT of things.
If the Amps knob is all the way counter clockwise, your risk is almost nill.
If you have it dialed full amps and you do a few hundred on off cycles, Good
chance you will be giving me a phone call.
If it is running at full power and you trip over the DC cable, you have a
50/50 chance of hurting it.
If it's running and it's at 435 volts at full current, You don't have a
chance at all.
Or you read the first page warnings that come will all the chargers... and
heed the warnings.
DO NOT operate this charger unloaded. This is a line item on the Warnings/
Scare page.
Then you won't be calling me with a problem.
I see this "unknown high side fail" about every other month. If it arrives
with a blown output fuse also... it's a "polarity reversal test" that
failed.
A true high side fail is a unfortunate result of having a Boost capable
power topology. It can boost until the 600 volt silicon flies apart, We have
2 shut down circuits and ouput storage caps to buy us more reaction time.
Still it happens... But more and more rarely. We are hoping the Iso may be
immune to this.
Keep in mind that I can't remember the last time I killed a power stage with
this happening. And I do unloaded tests all the time...So it's not that
common...
The RED led is the indicator that the unit has been over voltaged. If it
lights up at any other time but power up, you have just Zinged the power
stage over 450 volts. This can cause me much "pucker".
The monster charger's software would to this about every hour of operation.
The software would glitch and open the output contactor, the Chargers on
line would all light up all the LEDs Green for power on Red flashing for
over voltage yellow for over votlage peak and Blue for timer enable at
voltage peak... The dreaded blinking Christmas tree warning!!! Wanna see
Rich Run for the main breaker???
Over V $12,000 worth of PFC50s.....
So yea we are continuing to hunt this possible fail mode. It's getting
elusive. But not extinct ....yet.
Rich Rudman
Manzanita Micro
----- Original Message -----
From: "Ryan Stotts" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Friday, July 01, 2005 9:59 AM
Subject: Re: Another PFC Caution? (was: PDF-20 design flaw) (long)
> Chris Tromley wrote:
>
> > My understanding, which may not be clear, is that the PFC chargers are
quite
> > sensitive to being powered with no load.
>
> Are you saying if I plug in the charger and turn it on without it
> being connected to anything, it will blow the power stage?
>
> >That is not something that is mentioned in the manuals, and
> apparently is not >something that even an EE would expect.
>
> It needs to be for at least two reasons: Someone might plug it in and
> turn it on just to see if the charger works.. Someone might power it
> up without it being connected to the battery pack to adjust the
> settings beforehand..
>
--- End Message ---
--- Begin Message ---
Bob Rice wrote:
> EAAAH! I regulary unplug my pfc20 while turned on AFTER car is
> charged.
> Am I doing a serious BAD? Have plugged it back into the car after a quick,
> I'll -be- right- back store run, without turning it off. I'm using it as a
> Bench charger for now, not built in yet.
Hi Bob,
AFIK, plugging in and unplugging at the wall is not the issue here. Only
being powered with the DC load side open. It would seem to me though, that
using it as a bench charger is riskier than using it in your car - you'd be
more likely to disconnect the battery being charged or power up without
being connected to the battery. That's the danger, not the AC side. Still
need the official word from the experts.
Chris
--- End Message ---
--- Begin Message ---
Seppo,
IF you also want very zippy performance, you're better off staying
with at least 2 speed transmission. This means you wouldn't want to
use MES gear box. Single gear is OK for up to about 60-70 km/h
common in Europe.
My mathematics gives for MES motor (9000 rpm max) and Carraro gear
box: 115 km/h = 71 mph top speed (depends on tire size, as you said).
That is mathematics where everything works.
When you practically built it, you will see that the
whine of the first gear at 9000 RPM is intolerable,
the gear box too hot, the torque at 9k RPM very small and
no further acceleration is possible.
I can use single (2nd) gear only in ACRX, but find using first in
some situations is preferred(see faq on my site).
There is no need to limit the motor to 5600 RPM, but using it at
9000 RPM and only first gear is not a good idea either, because of
very high losses in the gear box - it will get real hot (aside the
flywheel problem which are solvable with small aluminum one).
I take it that it is ACRX specific, or ICE gearbox-related. I drive
a Peugeot Partner Electrique (you have certainly driven Jukka's similar
Berlingo).
It has a single-speed gearbox. I think the EV gearboxes have different
design
parameters so it is OK to drive continuously at high speed.
No, it is not ACRX specific.
Yes, I drove Jukka's Berlingo (it has SepEx DC motor BTW) and
I doubt I'd take it on the freeway here in the USA.
Peugeot has top speed of appr 100 km/h and accelerates OK in town
speeds,
With top sped 100 km/h you will bw run over quite quickly
in many places here. It is below leagal maximum on a freeway,
not to mention that this maximum is routinely exceeded by
15-20 km/h.
...
like a normal ICE car. No rocket but adequate for daily commuting. And
single-speed gearbox does not exclude even sports car performance, Tzero
has a single-speed gearbox.
Seppo
Tzero is no a car, not to mention not for every day commuting.
It is a money-no-object demo project where *everything* is
compromised just for the sake of acceleration, including the gear
box efficiency, bearings lifetime, etc. Their special motor does
12.5k RPM if I remember. It has to jave ~400V battery to do it,
far ftom Berlingo's pack either.
--
Victor
'91 ACRX - something different
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--- Begin Message ---
With all the talk about converting one of those Cobra kit cars...
The way it's constructed(the Factory Five model anyways), the frame
rails only go back as far as they need to go, and no more. The rear
structure looks to be built to facilitate the weight of the fuel tank
and nothing more.
If fuel weighs ~6lb/gal and it's a 14 gallon tank.. ~84 lbs hanging
off the support structure.
Now how many lbs of lead might this trunk support?
http://www.multier.com/picposter/FordGuy/IM001530.jpg
http://parts.factoryfive.com/roadster/chassis/frame1lg.jpg
---
Interestingly enough, the fiberglass body weighs 110 lbs and the frame
weighs 275 lbs..
http://parts.factoryfive.com/roadster/compparts/compparts.html
http://parts.factoryfive.com/roadster/chassis/chassis.html
A big go-cart..
--- End Message ---
--- Begin Message ---
Don and Victor,
Thanks for the advice and feedback, which is helping me to work through all
of these issues myself as well. Based on all of this and upon further
reflection and analysis, I can see that I really do want to keep (and use)
the gearshift, clutch, and transmission in the 914 for all of the
flexibility, advantages, and efficiency that will provide in my particular
application (which includes long-range highway driving).
After reviewing Victor's well documented account of his own conversion
process, I went and checked out Fidanza's and ClutchNet's websites.
Strangely enough, Fidanza offers lighweight aluminum flywheels only for
'70-'72 model year 914s but not for '73-'76 (mine is a '76). But it looks
like I can get everything I need for my '76 914 in one-stop shopping at
ClutchNet, namely a lightweight aluminum flywheel and high-performance
pressure plate and friction disc.
However, I don't think Steve and I are going to solve our other problem
(unrelated to motor/tranny issues but which nevertheless is holding up the
entire project) in time for me to get that last Siemens 5133 motor before
someone else grabs it. Therefore, I am changing gears (so to speak, no pun
intended) and starting to focus on the MES motor and reorient my plans
towards it rather than the Siemens. Aside from the fact that MES only
offers a measly one-year warranty (which seems strange for a Swiss company)
in contrast to Siemens' 10-year warranty, I would think it might actually be
better to buy from a company that has a continuous production line going
rather than one that only does a batch production run once every 5 years or
so depending on if and when it gets a sufficiently large order (> ~100
units) from an OEM. Not that there are very many parts that can wear out or
fail in these relatively bulletproof AC induction motors and
inverter/controllers, but with MES at least there is the peace-of-mind
factor of knowing that the motor & controller I bought are still in active
production. I mean, you know, well sure, Siemens has a 10-year warranty,
but one has to wonder how they're going to honor, service, and support that
warranty (if any customer ever needs it) when their surplus over-stock is
all used up, as is apparently now the case with the 5133 motor.
The big question I've got with the MES motor is regarding its lack of a
shaft, having that female internal spline, and whether there would be any
issues or problems in adapting that to my tranny. Anyone have any thoughts
on that? Victor, Don? Shari, Mike?
I assume that I would need to have machined a small custom shaft which would
be splined on one end (the end that goes into the motor) and smooth keyed on
the other end (the end that sticks out of the motor), and then Shari and
Mike could take it from there and do their thing. Is that right?
Of course the 18 kW Siemens 5105 (the surplus over-stock of which is
apparently now also depleted) is also shaftless with a female internal
spline, and I gather that there have been a few conversions with it, so I
guess people must have dealt with this particular issue, right?
Thanks,
Charles
Victor Tikhonov wrote:
Charles Whalen wrote:
Victor (and all),
...
But my application
is quite different. I am designing a long-range (220+ miles) highway
cruiser, so my preference is to optimize more towards higher speed
highway
driving.
IF you also want very zippy performance, you're better off
staying with at least 2 speed transmission.
This means you wouldn't want to use MES gear box. Single gear
is OK for up to about 60-70 km/h common in Europe.
I can use single (2nd) gear only in ACRX, but find using first
in some situations is preferred(see faq on my site).
There is no need to limit the motor to 5600 RPM, but using it
at 9000 RPM and only first gear is not a good idea either, because
of very high losses in the gear box - it will get real hot (aside
the flywheel problem which are solvable with small aluminum one).
I am planning to write MES in Switzerland and/or Carraro (not sure where
they're located)
Comex/Carraro boxes are made in Italy for MES-DEA. they deal with
OEMs only; there is no direct contact I know of. You're certainly
welcome to try.
to ask if there are other gear options with different
ratios that they can put into that Carraro single-gear reduction gearbox
that mates to the MES motor.
The options are listed on my site, also see downloadable PDF docs.
Don't forget, to some degree you can vary overall ratio by selecting
a tire size.
--
Victor
'91 ACRX - something different
Don Cameron wrote:
Charles, I am working through the same issues with my new project. You
will
find that without a transaxle, or a custom gearbox you will be hard
pressed
to find anything in the 5:1 to 7:1 range. One thing you may consider is
getting a lightweight flywheel (which can handle higher RPMs), or getting
rid of the flywheel and the clutch all together. That is what I did with
my
New Beetle project. I only shift it when it is stopped (although bold
people will shift on the fly). Most of the time it is in second gear for
around town use. Occasionally when I go on the highway, I just start off
in
third. Not having a clutch has negative sides as well, but since you are
looking at fixed gear anyways...
I noticed on Rod's Discovery channel program he is using belts to drive
the
motors, and this can give you the ratio you want with some fabrication.
I know Victor has a line on some 2:1 reducers and a two speed transaxle,
it
may work for your application.
Good luck, keep us informed.
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Charles Whalen
Sent: June 29, 2005 7:50 PM
To: EV Discussion List
Subject: Re: discontinued Siemens motors
Victor (and all),
Thanks for the update and clarification on the last 5133 currently
available
and the possibility that there might be more available again at some point
in the future at some price yet to be determined.
Steve and I are currently grappling with a particularly gnarly and nasty
engineering challenge (unrelated to the issue of motor selection) that has
slowed us up and is holding up further progress on the project until we're
able to solve it, so I wouldn't be surprised if someone else grabs that
last
5133 before I do.
But on the issue of motor selection and what had been my plans to go with
the Siemens 5133 (that is, until I just read on your website a few days
ago
about it no longer being available), with the advice and input of a few
other EVers, I had been looking into and discussing some of the challenges
of adapting the 5133 with its long splined shaft to my 914's existing
transmission. These discussions included things like possibly machining
an
additional bearing to support the 5133's long shaft as well as programming
the Simovert to limit the 5133's RPM to a maximum of 5600 (which is my
existing redline on the tach) so as to keep the tranny within its original
design specs and try to avoid the unfortunate fate that has befallen
others
where a heavy flywheel spinning at 7-9000 RPM ends up bending that long
shaft. I had deemed this to be an acceptable solution since the maximum
operating efficiency point of the Siemens motors appears to in the 5-6000
RPM range (at around 88% efficiency). So using a 5500 RPM shift point
would
let me drive in 2nd gear in town up to 46 mph and then shift up to 3rd
above
that for highway driving up to 69 mph, and for those rare occasions where
I
might need or want to briefly exceed 69 mph, I'd go up to 4th gear.
That's all well and good, although it does involve a bit of complexity.
However, in just the last two days that I have started to explore the MES
options (after finding out about the lack of availability of the Siemens
5133), I have started to realize and focus on the advantages of weight and
simplicity of going with the MES drive. The MES motor and inverter are a
fair bit lighter than comparable Siemens of the same power rating, and
with
the MES I can get rid of the 914's heavy tranny and use the lightweight
Carraro single-gear reduction gearbox, plus there are none of those
aforementioned adaptor challenges or having to think about shifting gears
and all of that. The simplicity is very appealing (KISS) and would seem
to
present a fairly robust drivetrain. Some have advocated going in this
direction by pointing out to me that almost every single OEM EV ever made
has used a single-gear reduction gearbox.
The only problem here is the inevitable trade-off and choice that must be
made between optimizing more for city driving or alternatively for
high-speed highway driving. When I run the numbers for my 914, it appears
to me that the 8.64:1 gear in the Carraro reduction gearbox has been
optimized more towards lower speed city driving. I guess that probably
makes sense for the primary application for this MES drivetrain over in
Europe, where I believe it is mostly being used in (OEM) tiny little
city-cars for urban driving, like the Smart EV, I think. But my
application
is quite different. I am designing a long-range (220+ miles) highway
cruiser, so my preference is to optimize more towards higher speed highway
driving. Just doing a rough, quick-and-dirty calculation, it looks like
maybe a 7:1 gear ratio would probably work better for me in that regard.
So
I am planning to write MES in Switzerland and/or Carraro (not sure where
they're located) to ask if there are other gear options with different
ratios that they can put into that Carraro single-gear reduction gearbox
that mates to the MES motor.
Any thoughts on that, Victor or anyone else?
Thanks,
Charles
Victor Tikhonov wrote:
Charles (and all),
One last 5133 motor will be available with either short Simovert 6-SV1 or
Simotion inverter. Whom ever grabs it first. They probably will be
available in some future, but the cost is unknown. This one still goes at
surplus price (brand new motor and inverter of course).
Charles Whalen wrote:
Just checking Victor's website (http://www.metricmind.com/motor.htm), I
noticed that some of the Siemens motors at the lower end of the power
scale have been discontinued, including the 18kW (cont.) 5105 and the
30kW
(cont.)
5133, the latter of which is apparently no longer available for
individual purchase in single quantities. It seems that Siemens must
not have been getting enough orders for the 5133 to keep up their
production line on it, as they will now only make a special order
production run of the 5133 motor for large quantity bulk purchases of
50-200 units. That's a bummer for me as the 5133 was my preferred
choice for my 914 conversion. The 45kW
(cont.)
Siemens 5135 (which apparently *is* still available) is a bit
overpowered and heavy for my particular application.
Does Victor or anyone over there in Europe know what's going on with
Siemens? Are they getting out of the motor business at the lower end of
the power scale (as it doesn't look like they are replacing these
discontinued motors with any newer models, from what I can tell from
Victor's website)?
I guess I'll have to look into the MES motors, although I don't believe
anyone over here in the States has done a conversion with them, at least
not that I can see on the EV Album. So that's a pretty big unknown as
far as the lack of any empirical record; no one to ask about their
experience with MES motors, although I heard that they are being used in
some limited production OEM EVs in Europe.
Charles
--- End Message ---
--- Begin Message ---
At 11:27 AM -0700 on 7/1/05, Victor Tikhonov wrote:
NG or NLG stands for "charging equipment" in German, it is generic
for this type of gear, not the model. I don't speak German so cannot
quote you.
Interesting. I wonder what it's actually short
for. "Charging Equipment" is "Ladeeinrichtung"
and "Battery Charger" is "Ladegerät" Probably
short for some technical jargon I don't know.
--
Auf wiedersehen!
______________________________________________________
"..Um..Something strange happened to me this morning."
"Was it a dream where you see yourself standing in
sort of Sun God robes on a pyramid with a thousand
naked women screaming and throwing little pickles
at you?"
"..No."
"Why am I the only person that has that dream?"
- Real Genius
--- End Message ---
