EV Digest 5344
Topics covered in this issue include:
1) RE: the $5000 car - could use some expert help
by Cor van de Water <[EMAIL PROTECTED]>
2) Re: Porsche 911 Was: How many amps driving my EV?
by David Dymaxion <[EMAIL PROTECTED]>
3) RE: Orb Carnage....
by Cor van de Water <[EMAIL PROTECTED]>
4) Re: Crazy DC regen idea, thoughts, comments (test)
by Jeff Shanab <[EMAIL PROTECTED]>
5) Re: Thermal measurements
by "Mike Phillips" <[EMAIL PROTECTED]>
6) Re: A cleaner EV genset.
by "David (Battery Boy) Hawkins" <[EMAIL PROTECTED]>
7) Greetings
by "Jonathan \"Sheer\" Pullen" <[EMAIL PROTECTED]>
8) frontal area
by Neon John <[EMAIL PROTECTED]>
9) NiCads (was: Greetings)
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
10) Amp Draw and Voltage Drop Questions
by "Tom" <[EMAIL PROTECTED]>
11) Re: CURRENT ELIMINATOR NEWS BOTL
by Rush <[EMAIL PROTECTED]>
12) Re: Porsche 911 Was: How many amps driving my EV?
by Stefan Peters <[EMAIL PROTECTED]>
13) RE: Amp Draw and Voltage Drop Questions
by Cor van de Water <[EMAIL PROTECTED]>
14) RE: adventures in electronics [maybe OT]
by Cor van de Water <[EMAIL PROTECTED]>
15) Re: Choosing the right career (was RE: Low efficiency with light loads)
by "damon henry" <[EMAIL PROTECTED]>
16) Re: adventures in electronics [maybe OT]
by Danny Miller <[EMAIL PROTECTED]>
17) Re: CURRENT ELIMINATOR NEWS BOTL
by [EMAIL PROTECTED]
18) Variable brush position for DC motor
by "David Sharpe" <[EMAIL PROTECTED]>
19) Re: Thermal measurements
by "Mike Phillips" <[EMAIL PROTECTED]>
20) Re: Thermal measurements
by James Massey <[EMAIL PROTECTED]>
21) RE: Crazy DC regen idea, thoughts, comments
by "David Sharpe" <[EMAIL PROTECTED]>
22) Charging Dead Flat AGMs
by "David Sharpe" <[EMAIL PROTECTED]>
--- Begin Message ---
Timm,
An EV would be interesting, but I read in your charter on this
Yahoo group that you want to use a 2-stroke Diesel.
To me that sounds like the wrong direction - you will increase
pollution and be far worse than most new cars on the road today,
so I urge you to re-think this path.
Besides efficiency, there is a lot to gain in a clean car engine
because a moped is efficient but nobody wants to run it indoors
and even outdoors it can be bad.
We have just been through this discussion in relation to use
of a generator as range-extender for an EV.
Incidental use may be beneficial, but the consensus is that
if you need it every trip, then you have the wrong solution.
The generator on an EV is not different than electric driven
wheels powered by a generator in your concepts.
If you want to innovate and save the environment, then the
generator should be comparable to a modern car (Hybrid) or
better. (Just giving you a challenge here ;-)
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of multi-Timm
Sent: Sunday, April 09, 2006 8:59 AM
To: [email protected]
Subject: the $5000 car - could use some expert help
We are well into the development of our $5000 kit car that pretty much
anyone can afford. It can be assembled as an EV or a hybrid, depending on
whether the owner prefers a generator or more batteries in it's place.
We're well covered on mechanical and design, but we do lack some
EXPERIENCED experts in electrical. Currently there are only one or two guys
who are expert and doing all the pulling in electrical, so the group could
use an extra person or two on the team. If anyone is interested, you are
most welcome to join us.
Hope to see you there:
autos.groups.yahoo.com/group/SmallEfficientVehicles/members
Timm
http://autos.groups.yahoo.com/group/SmallEfficientVehicles/members
T!MM! §
http://www.nrdc.org/wildlife/marine/nlfa.asp
http://groups.yahoo.com/group/Inventors-World/
http://groups.yahoo.com/group/CADoutsourcing/
http://autos.groups.yahoo.com/group/SmallEfficientVehicles/
"We don't see things as they are, we see them as we are" (Anaïs Nin)
---------------------------------
Enrich your life at Yahoo! Canada Finance
--- End Message ---
--- Begin Message ---
You do have to be careful. Some manufacturers want to make the Cd
sound as good as possible, so they'll just use the height*width of
the care for the area. I think one of the best sources for aero info
is <http://www.epa.gov/otaq/tcldata.htm>.
Unfortunately the fields are not well documented. In the earlier
years there is a column for effective frontal area, typical car
numbers run from about 7 to 11. In the later years there is a column
for coastdown time, but I haven't been able to find for what speed
range -- anyone know what that is?
About the effectiveness of a belly pan: I'm sure it would help,
especially on an electric. Electrics don't need to worry about hot
exhaust or radiator cooling. It would be nice if someone could do
some before-and-after coastdowns to see how much a bellypan would
help (I'm planning to do this). Just anecdotally, I've heard a
Corvette picked up 10 mph on the Salt Flats just by switching to
narrower tires, and about another car that picked up 7 mph just with
headlight covers.
If anyone would like to do coastdowns with their car, I have a
program that will calculate the rolling resistance and effective
area, I'd be happy to run the numbers.
--- Peter VanDerWal <[EMAIL PROTECTED]> wrote:
> I'd meant to mention that CdA was a more important measurement, but
> I
> couldn't find any good info on the frontal area of the vehicles in
> question (and using posted hight & width is highly misleading)
>
> I was kind of wondering about the Camry. I still think a Saab
> might make
> a better candidate since it seems to me they have a better load
> handling
> capacity than the Porsches, and close to the same CdA.
>
> I wonder what the CdA would be for a Porsche 914? As I recall the
> Cd
> wasn't all that great, but it seems to me that it has even less
> frontal
> area than a 911.
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
--- End Message ---
--- Begin Message ---
Lee,
Keep It Simple: let the car be without power for this split second,
even though it means switching under load.
It will be hard to find reliable 200+ Amp diodes that can take
the peak amps during switching (usually under the max load) and
be affordable enough to parallel every battery.
Besides, they do not add any functionality, only avoid burning
the relay contacts during closing (bouncing).
As a safety measure (not a daily operation practice) it sounds
unnecessary to add a diode.
Regards,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Lee Hart
Sent: Sunday, April 09, 2006 10:01 AM
To: [email protected]
Subject: Re: Orb Carnage....
Seppo wrote:
> What would happen if you simply connected a (very sturdy) diode in
> parallel with each battery? If the battery cannot keep in pace with
> the others and starts to go negative, the diode would start
> conducting the load current past the battery when the battery voltage
> is down to -0.7 V.
You can do this. But by the time a +12v battery drops to -1v (so the
diode conducts), that battery is in VERY bad shape!
However, the parallel diode trick has been used in packs of nicad cells.
A nicad cell taken down to -0.5v is *very* dead, but will survive.
But rather than a lot of big diodes (and their associated big
heatsinks), all to achieve a marginal solution, I think it would be
better to include a relay or contactor that switches the dead
battery/cell out of the series string. This requires a SPDT contact; one
to open the battery, and one to short around it. Probably also a diode
to carry the load current during the split second it takes the relay to
switch states.
--
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 ---
I think I found the setting that was messing up my ascii art to the list
here is that diagram again
B+______________________________________________
| __|__
| /_\ D1 ____
| | / \
| _______ o____|________A1__[ ]__A2______B-
|__B+_| zilla |M+___S1-field--S2___o==== K1 \____/ |
|_______|________________________o_________________________________|
||
__||____
|hairball|
|________|
| |
|-----|-----------|
/\/\/\/------------/\/\/\/-
PB6 throttle PB6 brake
12V----NO----------------NC-------------------K1coil-----gnd
D1 - SD1053C18S20L $127 at digikey 1000A 1800V diode
K1 - SPDT SW201 $175 evparts (would this be lrg enough?
Intended theory of operation:
During motoring K1 is in the NC position connected to A1 and current
flows from the zilla thru the field then the armature to pack neg.
D1 is reverse biased so it doesn't allow battery to feed arnmature.
When the throttle is released the NO switch on the throttle pot-box
closes and when the user presses on the brake pedal, a second potbox is
used. The NC closed switch is allowed to close as the braking throttle
is applied. K1 is pulled in and current begins to flow from zilla thru
the field to pack negative.
This fixed field is crossed by the armature coils and voltage is
producted and mechanically rectified byt the existing commutator.
This voltage, if high enough will cause D1 to conduct and push DC into
the Pack. since k1 has isolated A1 from the ground or the field.
How do I now make a DC-DC converter that can handle this or do I use a
second low voltage pack(cap bank?) that feeds a dc-dc slowly to recharge
the pack.
--- End Message ---
--- Begin Message ---
Thanks for the info Rich.
I have already made a schematic of your great hardware :)
Mike
--- In [EMAIL PROTECTED], "Rich Rudman" <[EMAIL PROTECTED]> wrote:
>
> The Manzanita Micro Mark 2 Regs use a NTC thermistor and a analog
set point
>
> The Mk3 Regs use a Lm34 Temps sensor.
>
> No I am not handing out schematics...
>
> Madman
>
> ----- Original Message -----
> From: "Mike Phillips" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Sunday, April 09, 2006 10:30 AM
> Subject: Thermal measurements
>
>
> > Has anyone measured their battery temperatures? Just curious what you
> > used and what numbers you got in various conditions.
> >
> > I'm secretly hoping for proven schematic with part numbers cause I'm
> > buried right now.
> >
> > But even meat thermometers qualify to answer the question.
> >
> > 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 ---
Peter and All,
You have a valid point about propane conversions that aren't done
correctly, but the conversion kit I mentioned in my original post comes
with an oversized regulator that has an idle mixture adjustment, and a load
block (needle and seat) assembly to adjust the mixture under load (url
below). I should have mentioned this, but I sometimes forget that not all
the people on this list are recovering gear-heads and could easily do a
conversion themselves! So, in addition to my comment about "if you can't
afford a diesel engine...", if you don't feel comfortable doing a propane
conversion, then you could pay a certified company to do the conversion or
buy a propane genny, if that's the route you want to take.
BB
>Date: Sat, 8 Apr 2006 10:11:30 -0700 (MST)
>From: "Peter VanDerWal" <[EMAIL PROTECTED]>
>
>Actually, propane /can/ burn cleaner than gasoline, but it's not a given.
>Propane conversions can, and often do, pollute MORE than gasoline engines.
>
>In fact most home conversions of automobiles ended up polluting MORE than
>they did as gasoline burners which is why it is currently ILLEGAL to
>convert a car to propane (in the USA) unless you are a certified converter
>AND you have to get certification for every vehicle you convert.
<snippage>
>Date: Fri, 7 Apr 2006 18:17:06 -0600
>From: "David (Battery Boy) Hawkins" <[EMAIL PROTECTED]>
>Subject: Re: 3kw genset for $315
>Date: Fri, 7 Apr 2006 18:17:06 -0600
>
>Bruce,
>I would suggest that if you MUST run a genny and can't afford a diesel
>engine (running bio-diesel), that you pick a model that has a propane
>conversion kit available. As I've posted before, I converted my 10kw Y2K
>special and use it as a range extender for the S10 EV. Since my genny has
>a big 20hp engine, I use two 20lb BBQ bottles Teed together. I'm assuming
>you use propane in your RV, so you probably already have BBQ tanks that
>you swap or have filled. You could also use the genny for RV backup power.
>No toxic stinking gasoline (which gets stale) or stinking exhaust, blah,
>blah, blah... Anyway, I bought a kit for my Honda engine at:
>http://www.uscarb.com/
>
>After writing the above, I read your follow-up post below. I would argue
>with your comment that LP isn't much cleaner than gasoline. I don't have
>the numbers handy, but having put an exhaust analyzer on my genny before
>and after conversion, the emissions were lower by something like a factor
>of four. I hated to be around the exhaust when it was powered by gasoline,
>but now with propane, I don't mind it. Now the noise is another story!
>Also, my FrankenLesters (transformer) and Soneils/Zivan (switcher) run
>fine on the genny.
>Hope this helps,
>BB
--- End Message ---
--- Begin Message ---
As many of you know, I kind of slipped out of the EV world (and arguably
out of any world) for the past two years. However, I'm back, and I'm
determined to install a NiCad or NiMH battery pack in quantum mechanic.
(alter ego sez: He just doesn't give up, does he folks)
I'm currently in negotiations with SAFT, but if anyone has any other
suggestions for NiMH/NiCad, please let me know.
My NiZn b
Minimum requirements:
55Ah
capable of sustained 100A/2C, bursting to 250A/5C
I'm willing to install a water cooling system if that turns out to be
advisable.
I will attempt to read this list regularly again. Sorry that I went
away.. bad things happened in my personal life.
Sheer
--- End Message ---
--- Begin Message ---
On Sun, 9 Apr 2006 14:12:57 -0700 (PDT), David Dymaxion
<[EMAIL PROTECTED]> wrote:
>You do have to be careful. Some manufacturers want to make the Cd
>sound as good as possible, so they'll just use the height*width of
>the care for the area. I think one of the best sources for aero info
>is <http://www.epa.gov/otaq/tcldata.htm>.
Here's a very accurate method of measuring the frontal area of your
car. It is a variation of the old scientist's trick called graphical
integration, updated for the digital world.
First, get 4 yard sticks or other known length objects and make a
square. Position this square upright in front of the car.
Take your digital camera, zoom it to maximum optical power and get
back from the front of the car ever how far it takes to make the car
fill most of the frame. Squat down or put the camera on a tripod so
it is looking straight at the car at the level of its centerline.
Snap the photo. Make two prints on as heavy a paper or cardboard as
your printer will feed. Resolution or quality does not matter.
You'll need some sort of small scale or balance. An electronic
postage scale will work, as will a jeweler's scale (go to the jewelry
store if you have to), as will those little scales sold in head shops
for cutting dope :-)
Take one print and very carefully cut out the square. If you used
yard sticks, that square represents 9 sq feet. Weight the square.
Divide the weight by the area (9 sq ft) to get the weight per square
foot.
Next, very carefully cut out the outline of the front of your car.
Weight that cut-out. Divide the weight by the weight per square foot
that you computed above. Viola! The result is the area of the
frontal area in square feet.
This is a very easy procedure and is amazingly accurate.
Oh, the old scientist's trick? To integrate a curve, plot your data
on graph paper. Weigh the graph paper with the border removed, if
appropriate. Then cut out the curve along the X-axis and weight it.
Some simple ratio math and you have your area under the curve.
There is some freeware software out there that can compute the area of
a designated data plot or image. I have it but I don't recall where
it came from. Frankly, it's easier and faster to just cut out the
shape and weigh it.
John
>If anyone would like to do coastdowns with their car, I have a
>program that will calculate the rolling resistance and effective
>area, I'd be happy to run the numbers.
Why don't you make that program available to list members? I have one
that I wrote a LONG time ago. It won't run under winders or else I'd
make it available.
It would be nice to have a program out there for everyone to use so
that our computations would be identical.
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 ---
I have the SAFT MRE-100's in my Wabbit. So far, so good.
Water cooling is the way to go, but a pain to implement.
If I had it to do all over again, I think I would buy super high
quality rubber hose and drill just the right size holes in the side
of it to push onto the barbs on the batteries. Maybe lube up the
holes with RTV to be sure of a good seal.
I may actually do it this way when I get tired of fixing
leaky connections. :-)
I bought these when the Euro was about equal to the dollar.
That is no longer the case now. :-(
Bill Dube'
At 03:21 PM 4/9/2006, you wrote:
As many of you know, I kind of slipped out of the EV world (and
arguably out of any world) for the past two years. However, I'm
back, and I'm determined to install a NiCad or NiMH battery pack in
quantum mechanic.
(alter ego sez: He just doesn't give up, does he folks)
I'm currently in negotiations with SAFT, but if anyone has any other
suggestions for NiMH/NiCad, please let me know.
My NiZn b
Minimum requirements:
55Ah
capable of sustained 100A/2C, bursting to 250A/5C
I'm willing to install a water cooling system if that turns out to
be advisable.
I will attempt to read this list regularly again. Sorry that I went
away.. bad things happened in my personal life.
Sheer
--- End Message ---
--- Begin Message ---
A few questions on power,
I would like to know what the amp gage should show under full
acceleration with a full battery pack, 144VDC, 12 Dynasty 134 amp hr
batteries, and a Curtis 1231c 8601 Controller (max current 500 amps). I
am running a 9.1 motor. I have the amp gage before the controller. And
what would the amp gage show if it were placed between the controller
and motor?
What is the voltage sag on a set of AGMs, this case Dynasty, under full
load, full charge, above controller and motor? And what would the
voltage sag with 8V lead acid be?
Thanks ahead of time to anyone who can reply.
Tom Shjarback
--- End Message ---
--- Begin Message ---
Congratulations!
When are you coming to Tucson?
Rush
Tucson AZ
www.ironandwood.org
----- Original Message -----
From: <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Saturday, April 08, 2006 4:40 PM
Subject: Re: CURRENT ELIMINATOR NEWS BOTL
> We ran in the super pro adra series race today and for the 2nd time in 2
> weeks went to the final round.Worst reaction of the day .011.In the final I
> ran
> the # 1 Arizona racer and points leader Mike Zimerman.I lost by .001 seconds
> in
> a breakout. Dennis Berube BEST OF THE LOSERS
>
>
>
--- End Message ---
--- Begin Message ---
Robert Baertsch wrote:
The Saab weighs 3200 lbs and I would like to stay under 2500 for my
starting vehicle.
I'm leaning toward the Toyota Pickup with Phil Knox's aerodynamic mods
that reduce the Cd from 0.44 to 0.25. Which would bring the CdA to
7.0. Smoother than the Saab and less weight.
Are there other candidates?
Well... call me nuts but there *is* the toyota supra. If you want to
pack in lots of batteries, pick the early ones:
1980 -> 2700lbs stock (with a 2.6 6 cylinder), 7.03 Cd*ft2 drag, RWD
with a beefy transmission, sturdy rear-end and a stretched frame for
plenty of space.
Picture: http://www.evforge.net/pub/index.php?code=1144623780EFYJVUJ2XT
--- End Message ---
--- Begin Message ---
Tom,
Assuming that this is your battery:
http://www.powerfactorinc.com/Batteries/ups12-475.htm
It specifies 2.3 milliOhm per battery, so a string of 12
should have at least 12 x 2.3 = 28 milli-Ohm.
Unfortunately we also have cable resistance and contact
resistance - even if you really try will it be hard to
have a resistance that is lower than the battery's internal
resistance, also dependent on the wire size.
Count anywhere between 50 - 100 milliOhm resistance
after the cabling, breakers, fuses, contactors and the
cable run to your controller.
So a 500A draw should bring you down between 500 x 0.05 = 25V
and 500 x 0.1 = 50V.
Since a 144V AGM pack will sit around 150V (160V after charging)
you should see it sag to between 125V and 100V, dependent on the
actual internal resistance of all components in your battery system.
Resulting power into your controller is between 62.5 and 50 kW.
Hope this clarifies,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Tom
Sent: Sunday, April 09, 2006 1:30 PM
To: [email protected]
Subject: Amp Draw and Voltage Drop Questions
A few questions on power,
I would like to know what the amp gage should show under full
acceleration with a full battery pack, 144VDC, 12 Dynasty 134 amp hr
batteries, and a Curtis 1231c 8601 Controller (max current 500 amps). I
am running a 9.1 motor. I have the amp gage before the controller. And
what would the amp gage show if it were placed between the controller
and motor?
What is the voltage sag on a set of AGMs, this case Dynasty, under full
load, full charge, above controller and motor? And what would the
voltage sag with 8V lead acid be?
Thanks ahead of time to anyone who can reply.
Tom Shjarback
--- End Message ---
--- Begin Message ---
One suggestion:
The 4-wire heatsinked "switch" nex to a big capacitor
is most likely the rectifier.
I would not worry about the capacitor.
It takes a long time to destroy it with reversed
polarity and you said you saw instantaneous smoke.
Most likely a transistor burned, but you can's see
from the outside unless it is real bad.
If you smoked something, it is likely going to be
near or connected to one of the 2N3055 as they are
the power outputs.
You should be able to check these two transistors
with the 'diode' measurement setting and each should
have one pin that acts as a diode (conducts in one
direction) to the second pin and to the metal case.
This pin is the "Base" and is used to drive the transistor
(connecting the other pin to case) with a small current.
If there is no pin that acts as diode or if it conducts
in two directions (swapping meter leads and you know)
then the transistor is bad >or< the current is conducted
outside the transistor: make sure you disconnect the
wires to the pins when measuring.
Hope this helps,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]
Behalf Of Arthur W. Matteson
Sent: Saturday, April 08, 2006 11:37 AM
To: [email protected]
Subject: Re: adventures in electronics [maybe OT]
Hi Fortunat,
We may want to move this to EVTech. I am a member.
I recently repaired a laptop that I burnt out from giving it 40V instead
of 20V by replacing three surface-mount parts. I also repaired a
soda-covered LCD computer screen that my friend found in the dumpster,
by means of acetone and actually permanently removing a circuit board.
There is much value in restoring electronic products, especially
large/expensive ones!
My power supply, which is almost identical but possibly older, recently
lost a capacitor to slight overvoltage. I believe it failed short. It
was easily replaced. (A short can be tested by putting the meter on
something of a "1k-ohms" scale and applying it in both directions to the
capacitor. At least one direction should show a resistance increasing
to almost infinity.)
Do you mean "relay," by "switch"? A relay probably wouldn't fail in
this case. Rule out the transistors first and the capacitor second.
The smaller solid state switch (TO-220 package?) could be either a BJT
or a MOSFET. See if you can read the part number.
Your TO-3s are these transistors:
http://www.onsemi.com/pub/Collateral/2N3055-D.PDF
In both of these packages (TO-3 and presumably TO-220), the tab or case
is the collector/drain. On the TO-220, the center pin is always
connected to the metal tab. This can be verified with a meter. Looking
at the part number so you can read it, the TO-220's left pin is usually
the base/gate and its right pin is usually the emitter/source. A
diagram is shown from the bottom for the TO-3 on the PDF file above
(last page).
Bipolar junction transistors should read about 600mV of drop when one
meter probe is on the base, and the other is on either the emitter or
collector. For my meter, NPNs use the meter's red wire on the base and
PNPs use the meter's black wire on the base. Placed the wrong way, they
should read open with a standard multimeter. Refer to your meter's
manual on how to perform a voltage-drop measurement, or a resistance in
the k-ohms (which may show around 6k ohms).
MOSFETs (which are probably N-type in the power supply) should read
about the same when the black lead goes to the drain and the red lead
goes to the source. The gate should be open to either. When it fails,
you'll almost always see a gate-to-drain short (resistance < 10 ohms).
This toasts gate-drive circuitry! If this is the problem, whatever
connects to the gate might be blown too (but can be replaced).
Note that these measurements have been taken with the parts out of
circuit. A MOSFET should show a gate-to-source resistance of around 5k
to 50k ohms in-circuit, as long as the red meter lead is on the gate.
Give us an update after you make those measurements, and note the
TO-220's part number. On EVTech is preferable (it can be signed up for
immediately).
Just one more note - if you come across something that looks like a part
number, do a Google search for it! You might be amazed at how easily is
it to find the datasheet. Anything that starts with "1N" is generally a
diode, and with "2N" is generally a bipolar junction transistor.
- Arthur
> Hi all,
> ...
> when the supply fried, i saw just a tiny wisp of smoke
> come out of the supply. It seemed like it came from an
> area in the case where there are not a lot of
> components, so I thought I would start there to see if
> I could find a bad part. There are two main parts in
> that area. One is a capacitor (labeled 63 V, 3300uF),
> the other is a solid state switch (fet?) that is about
> 1/2 in squared and is heat sinked to the base of the
> supply. Neither looks obviously burned.
>
> so my question, how can i test those individual
> devices ? Is there something I can do with a
> multimeter to see if the Cap is ok ? My DMM has a
> setting for CAP, but i have never used it. what is the
> failure mode for a cap anyway ? shorted ? loss of
> capacitance ?
>
> what about the 'switch' ? It has four leads coming off
> it and two of them appear to be tied to together by a
> resistor (R-Y-Br-R; is that 240 ohm?). Should I assume
> those two are the 'coil' and the others are the
> contacts ?
> anyway to check to operation of this device ?
>
> Finally, at the back of the supply there are two
> circular discs mounted on a big heat sink. They look
> like thermal snap discs or something, and have part
> number " Greaves Limited 2N3055HV" printed on them ?
> What is the function of these ? They both read 'open'
> between the pins, which seems odd if they are over
> temperature protection (since it is about 40 degrees
> in my garage today).
> ...
> ~fortunat
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--- Begin Message ---
Hi Seth,
Sounds like we are in similar fields. It was actually exposure to computers
that made the grind of finishing my EE seem so bad. I spent my first two
years at a community college working on an Electrical Engineering Technology
track with plans to transfer to a 4 year school. During my first two years
of course work I was required to take some computer classes and found that
this line of work was my true calling.
After earning my Associates Degree I transferred to the 4 year school, but
the engineering became "tedious" especially since much of what I was being
asked to do I knew could be handled by computers. I dropped out and went to
work in the computer industry. I have spent much of my time administering
different types of systems. I get my biggest kicks out of automating tasks,
so I have a similiar mix of programming, administration and thinking outside
the box. It's coming up with simple elagant solutions to what seem to be
complex problems that really toots my horn.
Over the years I have evaluated tons of different software and tools. I
have to force myself to be thorough and complete. It does not come
naturally too me, but when I slip into this mode, I feel like I am working
like a real engineer, and I am glad that I don't have to force myself to
work this way fulltime. I think if I would have stuck with electronics I
would have been more suited to be a technician than an engineer.
When I built my motorcycle, I did not do any engineering up front. I simply
sought the advice of people who had come before me, and started building.
As soon as I could, I was tooling around with a battery, a motor, and a pair
of jumper cables.
BTW - I was recently looking through some employment adds and found a firm
that had a pitch that totally sucked me in. It was for some type of
computer firm for which I would have good credentials, and their whole theme
had to do with the fact, that "You're not just a computer geek, your are
really an artist." That totally appealed to me. I think that if you find a
niche where you can consider your work to be art, you are probably in the
right spot.
damon
From: Seth Rothenberg <[EMAIL PROTECTED]>
To: damon henry <[EMAIL PROTECTED]>
Subject: Re: Choosing the right career (was RE: Low efficiency with light
loads)
Date: Sun, 09 Apr 2006 16:43:18 -0400 (EDT)
So, Damon,
>>> I'm very happy in my current career...
after you say that, you simply must tell us
what you do...
I started out in Mech engineering but was in outer space
for a couple of semesters, so I switched to a computer
field, and now I am a Systems Integrator
(that means light programming, heavy sys adm, and
thinking far outside the box :-)
(...and now trying to figure out if building EV's
can be called Systems Integration and if a person
can make a livelihood....doing it in New Jersey... :-)
I bought a motor in a donor vehicle with wiring
(and dead batteries), and now I need to choose all
the other components (and then see if it works....and
then see if I can do it for others and make money :-)
Seth, (tired of commuting, traffic, and certainty
that an EV can't make the round trip :-)
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--- Begin Message ---
It's really hard to say. A cap can certainly be damaged in moments by
reverse voltage. But then a lot of components are vulnerable.
The analog circuitry that was used to make the voltage readout is quite
vulnerable- applying reverse voltage can toast an op amp in a flash.
But again it's hard to say, I don't know what kind of circuit they might
have used.
I'd certainly start with power transistors and such though, primarily
because they're easiest to diagnose and find replacements for. In
short, start with the easy parts.
Danny
Cor van de Water wrote:
One suggestion:
The 4-wire heatsinked "switch" nex to a big capacitor
is most likely the rectifier.
I would not worry about the capacitor.
It takes a long time to destroy it with reversed
polarity and you said you saw instantaneous smoke.
Most likely a transistor burned, but you can's see
from the outside unless it is real bad.
If you smoked something, it is likely going to be
near or connected to one of the 2N3055 as they are
the power outputs.
You should be able to check these two transistors
with the 'diode' measurement setting and each should
have one pin that acts as a diode (conducts in one
direction) to the second pin and to the metal case.
This pin is the "Base" and is used to drive the transistor
(connecting the other pin to case) with a small current.
If there is no pin that acts as diode or if it conducts
in two directions (swapping meter leads and you know)
then the transistor is bad >or< the current is conducted
outside the transistor: make sure you disconnect the
wires to the pins when measuring.
Hope this helps,
Cor van de Water
Systems Architect
Email: [EMAIL PROTECTED] Private: http://www.cvandewater.com
Skype: cor_van_de_water IM: [EMAIL PROTECTED]
Tel: +1 408 542 5225 VoIP: +31 20 3987567 FWD# 25925
Fax: +1 408 731 3675 eFAX: +31-87-784-1130
Proxim Wireless Networks eFAX: +1-610-423-5743
Take your network further http://www.proxim.com
--- End Message ---
--- Begin Message ---
In a message dated 4/9/06 3:56:11 PM Pacific Daylight Time,
[EMAIL PROTECTED] writes:
<< Congratulations!
When are you coming to Tucson?
Rush
Tucson AZ
www.ironandwood.org >>
Not till the fal when there are a couple $5000 days. Dennis Berube
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--- Begin Message ---
With regards to thread on regeneration lately another idea might be a brush
set whose position can be altered by some sort of servo driven by a feedback
control system using an auxiliary brush set that looks for a position of
minimum voltage drop. The brushes would be parked in a neutral position but
the "polarity" of the auxiliary brush pair would tell the control system
which way to send the brush set.
David Sharpe
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--- Begin Message ---
Roland,
Thanks so much for your information. I had forgotten that the Emeter
has that capability. I'm not sure if it's optional or not. I'll see if
mine can measure temperatures as well. Do you remember how long the
temp probe cable was? Mine would have to route something like 10 feet
or more to reach a battery. If it's a solid state device, the wires
could be lengthened. If it's a thermocouple, then it can't.
But in the mean time the Acurite stuff would work just fine for
nailing down the thermal behavior of the pack. I wish the dolphin had
a thermal measurement as well for the pack, then I could log it while
driving/charging.
I wish I had room for insulation. I will also have to look closely at
ventilation as well for excess heat. I've got some serious research to do.
Thanks again!
Mike
--- In [EMAIL PROTECTED], "Roland Wiench" <[EMAIL PROTECTED]> wrote:
>
> Hello Mike,
>
> To read my battery pack temperature on the go, I'm using a temperature
> sensor that is design for the Link-10 E-meter.
>
> It is a two wire temperature sensor that connects to the No. 6 and
No. 8
> terminal strip on the back of the Link-10. The part No. for this
sensor is
> 1N2535.
>
> The sensor is bolted on any one of the battery post. The
temperature prod
> is imbedded in side a wire lug and isolated from any metal of the
wire lug.
> The wire lug is than either bolted to a extended battery post clamp
or a
> battery stud.
>
> This morning, in Great Falls, Montana, it was 40 degrees F. Inside my
> garage the on wall temperature is 65 degrees F. I turn off the heating
> system for the winter, but I have a super high R-factor insulation
that is
> 80 R's for the wall and 140 R's ceiling and a garage door of 20 R's,
so it
> maintains this temperature for a long time and even into the summer.
>
> The battery pack is also in a super insulated battery box, so even
after
> driving the EV, it will hold the battery temperature range from 62
to 65
> degrees.
>
> This morning when, the battery temperature was at 17 degrees C. or
62.6 F.
> Driving for one mile at 50 battery amp, the temperature rose to 18
degrees
> C. or 64.4 F. After letting the EV set one hour in a outside ambient
> temperature of 40 F. the Link 10 still had a read out of 18 C. It
may be
> between 17.5 and 18 C.
>
> This is with a 260 AH battery pack that weighs more than a ton. A
smaller
> pack at a lower AH will increase in temperature faster and lose the
> temperature quicker.
>
> Driving home for another mile at 50 battery amp the battery temperature
> still read 18 C. Letting the EV set for 20 hours, the temperature
will be
> down in the 17 C. range or about 62+ F.
>
> If you battery pack is un-insulated, then the battery post will be
the same
> temperature as the ambient air very quickly.
>
> To read the temperature on a Link-10, press F3 for a read out.
>
> Before I had a Link-10, I used a small battery operate temperature
gage made
> by ACURITE which you can get from WalMart. It has a 10 foot cable and
> sensor, normally for reading outside temperature from inside you
house. I
> used many of these sensors, when I was building my high R-Factor
house, for
> testing the floor to ceiling and inside wall to outside ambient
temperature.
>
> I normally keep my battery pack in about the 65 degree range all winter
> long. In summer, the battery back temperature is between 70 and 75
F. I do
> not drive that far, so I do not have to squeeze every AH out it. I get
> about 2000 cycles out of my batteries, because I at 80% capacity
about 95%
> of the time. For me this is about 100 cycles per year or would be
20 years.
> I normally get 10 to 12 years out of a battery pack.
>
> Roland
>
>
> ----- Original Message -----
> From: "Mike Phillips" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Sunday, April 09, 2006 11:30 AM
> Subject: Thermal measurements
>
>
> > Has anyone measured their battery temperatures? Just curious what you
> > used and what numbers you got in various conditions.
> >
> > I'm secretly hoping for proven schematic with part numbers cause I'm
> > buried right now.
> >
> > But even meat thermometers qualify to answer the question.
> >
> > 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
> >
> >
>
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At 02:14 AM 10/04/06 +0000, Mike wrote:
<snip>I'll see if
mine can measure temperatures as well. Do you remember how long the
temp probe cable was? Mine would have to route something like 10 feet
or more to reach a battery. If it's a solid state device, the wires
could be lengthened. If it's a thermocouple, then it can't.
G'day Mike, and all
This is probably just a mis-use of terminology (you probably know what you
mean), but a thermocouple can be lengthened, no problem, as it is made from
wire. You just need to use thermocouple wire to do it with. Other types of
electronic-signal sensor usually can be lengthened with ordinary copper
wire (I can't actually think of any that can't).
Since you're talking about an electronic meter the sensor will not be a
capillary tube - which are the type you can't lengthen as they are a sealed
system.
Regards
James
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-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Lee Hart
Sent: Monday, 10 April 2006 3:26 AM
To: [email protected]
Subject: Re: Crazy DC regen idea, thoughts, comments
To comment on Lee's suggestion
With the blower now needed because of the fan removal you have an
opportunity to recover some heated air (complete with graphite & commutator
copper dust) for cabin heating in winter. The extra set of brushes due to
the slip rings will cause an extra frictional load on the armature. This
made me think is there anything else we can do? Why not now turn the motor
into an AC synchronous machine? You will still need the high amperage field
of the series motor -this can come from the "line" current but if you also
feed the armature with a variable frequency 3 ph AC source will we not now
have a hybrid AC machine? This is a different approach from the normal AC
machines which are higher voltage. I think the low frequency AC at start off
will need to be lower voltage as well to avoid saturating the armature but
maybe the required 3 ph inverter can piggy back onto the DC controller.
Regeneration will be as discussed by Lee. You could lift the commutator
brushes so that they are not in contact so that if your hybrid controller
failed you might get home on the normal DC controller by lowering the
brushes and altering links. This should enable a much cheaper AC design
using the relatively cheap low voltage Mosfets & IGBTs that could be used on
the more usual pack voltages that go to about 160V. Conversion work could
keep Jim busy for years.
David Sharpe
Melbourne Australia
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Has anyone been able to charge flat AGMs. I have tried charging using about
50V DC in series with a 100W light bulb. 2V appears on the terminals but the
trial cell will not charge. Any suggestions?
David Sharpe
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