EV Digest 4888
Topics covered in this issue include:
1) Dark & stormy night in OR; successful repair
by Bob Bath <[EMAIL PROTECTED]>
2) Re: Front End
by "Joe Strubhar" <[EMAIL PROTECTED]>
3) unsubscribe
by "Thomas Niccum" <[EMAIL PROTECTED]>
4) RE: OT: Is this nonsense?/moon power
by "Andre' Blanchard" <[EMAIL PROTECTED]>
5) Re: multimeter
by "John G. Lussmyer" <[EMAIL PROTECTED]>
6) Re: multimeter newbie question
by Carmen <[EMAIL PROTECTED]>
7) Re: multimeter
by Eric Poulsen <[EMAIL PROTECTED]>
8) Re: Bits and Pieces - air vs water cooling
by Fortunat Mueller <[EMAIL PROTECTED]>
9) =?iso-8859-1?Q?Re:_multimeter?=
by "[EMAIL PROTECTED]" <[EMAIL PROTECTED]>
10) Re: multimeter
by "Lawrence Rhodes" <[EMAIL PROTECTED]>
11) Re: multimeter
by [EMAIL PROTECTED]
12) Re: multimeter
by "STEVE CLUNN" <[EMAIL PROTECTED]>
13) Re: Dark & stormy night in OR; successful repair
by Lee Hart <[EMAIL PROTECTED]>
14) Re: multimeter
by Lee Hart <[EMAIL PROTECTED]>
15) Re: DCP DC/DC Converter
by "Rich Rudman" <[EMAIL PROTECTED]>
16) RE: multimeter
by "Don Cameron" <[EMAIL PROTECTED]>
17) RE: EVs on Globe Trekker
by "damon henry" <[EMAIL PROTECTED]>
18) Re: Front End
by "Paul G." <[EMAIL PROTECTED]>
19) Re: multimeter
by Eric Poulsen <[EMAIL PROTECTED]>
20) Re: EVs on Globe Trekker
by Travis Raybold <[EMAIL PROTECTED]>
21) Power Management
by "Stefan T. Peters" <[EMAIL PROTECTED]>
22) Re: Bits and Pieces - air vs water cooling
by Lee Hart <[EMAIL PROTECTED]>
23) Re: Honda FCX goes for a test drive
by Fortunat Mueller <[EMAIL PROTECTED]>
24) Re: Dark & stormy night in OR; successful repair
by Ryan Stotts <[EMAIL PROTECTED]>
25) Re: Solectria controller connecting w/PC (Hyperterminal)
by "David" <[EMAIL PROTECTED]>
26) Re: multimeter
by Neon John <[EMAIL PROTECTED]>
--- Begin Message ---
Last night I headed back into our town from 9 miles on
the outskirts at my parent's house. Light rain.
Hmmm, that's funny, my wipers are going pretty slow.
5 miles later... Hmmm, that's funny; headlights seem
dim. Okay, something's not right. When I let off the
accelerator, I should have a DCDC pumping at least
6.0A to charge the aux battery, and the E-meter reads
0.0 when I let off it. Either I've got a fried DCDC,
or a dead fuse.
Thank heavens for a flashlight in the glove box and
spare fuses. Sure enough, I'd lost the DCP DCDC fuse.
Popped in another, and there's my 6.0A going back to
a very thirsty aux. batt.
So the way I see it, DCP is a 300W unit. That's 25A
or so on the 12V line. Headlights, wipers, radio,
defroster blower. How did it blow a 30A fuse?
Must've been the jarring over bumps, is all I can
figure...
At least a very happy ending.
Now to write an owners manual for someone, in case
someone else eventually owns this, so that they know
how to do these types of things...
C-ya,
'92 Honda Civic sedan, 144V (video or DVD available)!
www.budget.net/~bbath/CivicWithACord.html
____
__/__|__\ __
=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?
__________________________________
Yahoo! FareChase: Search multiple travel sites in one click.
http://farechase.yahoo.com
--- End Message ---
--- Begin Message ---
Longer ago, all vehicles had kingpins - my very first vehicle, a 1964 Ford
F150 I bought used, someone had tried to replace the kingpins themselves and
they were so tight that it took all my strength to turn the steering wheel!!
I had a professional mechanic redo them, and they had to practically destroy
the one steering arm to get the old ones out.
Joseph H. Strubhar
E-Mail: [EMAIL PROTECTED]
Web: www.gremcoinc.com
----- Original Message -----
From: "Mark Hanson" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, November 07, 2005 5:42 AM
Subject: Front End
> Hi,
>
> I have King Pins on this Bombardier 99' EV and was curious if anyone is
familiar with putting another vehicle ball joint type front end or modifying
king pins to remove the slop. Apparently the small king pins used introduce
steering instability. Do any normal vehicles use king pins? I thought all
were ball joints with upper & lower control arms.
>
> I added an anti-sway bar from a Mazda B2000 pickup to help the cheesey
wishbone suspension. Peacockltd, the distributor said 10K bomb's were made
but now I think it's more like 10 since I havn't heard any others on the
list with one. I got all the electrical stuff working now since I replaced
everything.
>
> Thanks, Mark
>
>
--- End Message ---
--- Begin Message ---
--- End Message ---
--- Begin Message ---
At 05:05 AM 11/6/2005, you wrote:
See Wikipedia for a good illustrated description of the physics behind
earth's tides.
http://en.wikipedia.org/wiki/Tides
While the mass of the moon makes the oceans slosh into tide shapes (high
at 0 and 180 degs from the moon, low at 90 and 270 degs) it is the
earth's rotation relative to the moon that makes the tides go up and
down.
(If the earth rotated once every 28 days or so, so that the moon was
always above the same point on the earth, the tides would be stuck.)
Anyway, it is the tides going up and down that allows us to extract
energy from them, so it is really the earth's rotation providing the
energy.
As we remove this energy, the earth slows down a tiny little bit.
Scary huh? :-) (After a couple of billion years it might make a
measurable difference.)
Mark
It hardly takes a billion years to be measurable it is about 1.5 to 2
milliseconds every 100 years.
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980421b.html
__________
Andre' B. Clear Lake, Wi.
--- End Message ---
--- Begin Message ---
At 03:52 AM 11/7/2005, Dale Curren wrote:
I just checked out Flukes. Wow!
Is there nothing that doesn't cost a weeks pay?
Ebay.
--
John G. Lussmyer mailto:[EMAIL PROTECTED]
Dragons soar and Tigers prowl while I dream....
http://www.CasaDelGato.com
--- End Message ---
--- Begin Message ---
When testing my voltmeter with a multimeter (Mastech, hope it's an OK one).
Do I put the black wire to the car body and the red to test leads or what?
My voltemeter stoped working but my ampmeter still works.
Carmine in Sacramento
--- End Message ---
--- Begin Message ---
I didn't know that ...
Joe Strubhar wrote:
Those Fluke 77's are lifetime warrantied - if it's gone belly-up. you should
be able to get it repaired for free!
Joseph H. Strubhar
E-Mail: [EMAIL PROTECTED]
Web: www.gremcoinc.com
----- Original Message -----
From: "Eric Poulsen" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, November 06, 2005 10:44 PM
Subject: Re: multimeter
Neon John wrote:
On Sat, 5 Nov 2005 11:58:40 -0800 (PST), Ken Albright
<[EMAIL PROTECTED]> wrote:
I beginning to collect tools for my conversion project
(the whole reason for any project, right?). One is the
multimeter. Besides DCV to 2 or 3 decimal places, what
else do I need? Any recommended brands/models?
There is basically Fluke and the rest of the random data generators.
yeah, they're expensive but worth every penny.
I have to agree with John. I'm in the market for a new multimeter, as
half the functions on my (15-year-old-was-used-when-I-got-it) Fluke 77
don't work, including the Amps and the 300mV (fuses are good -- thing is
just borked).
I spent years repairing test equipment. Most of it was Fluke,
Tektronics and HP. Guess what I own now? Fluke multimeter, Tektronics
scope. Haven't (yet) had a need for a counter, wave gen, but when I do,
it will be one of those brands. Don't bother with the $20 meter you see
at Sears -- get good equipment.
--- End Message ---
--- Begin Message ---
Lee,
As usual, an excellent post. But i take exception to
one thing:
--- Lee Hart <[EMAIL PROTECTED]> wrote:
>
> Let's step back for a moment. Your EV is *always*
> air-cooled, regardless
> of whether your cooling system uses water or not.
>
> To transfer a lot of heat to air, you need a large
> surface area and/or a
> large volume of airflow. The surface area and
> airflow needed are *not
> affected* by whether you use water or not!
i don't think the above statement is absolutely true.
If you fix the quantity of heat to be rejected, the
temperature of the source, and the temperature of the
sink, then adding an additional heat transfer step
(water cooling) will increase either the size or
airflow required for the final radiator.
Each heat transfer step will reduce the grade of the
heat (ever so slightly) so having an additional heat
transfer step will reduce the LMTD of the final
radiator (assuming fixed ambient air conditions). So
the final radiator either needs to grow, or needs to
have more air to move the same heat.
while this effect can be small depending on the
efficiency of your various heat exchange steps, it
does exist.
sorry this post is late to the party. I was out of
town for a week and it seems to take about 2 weeks to
catch up with the EVDL.
~fortunat
__________________________________
Yahoo! FareChase: Search multiple travel sites in one click.
http://farechase.yahoo.com
--- End Message ---
--- Begin Message ---
Lifetime warranty is sign of quality :^)
When looking for Fluke, Ebay is your friend, i import mine from USA and though
i'm still looking for IR-RS232 interface/software for it i really LOVE my 189
(data logger)
I paid 325$ for a new one, other the pond delivered, when french price is
500euros which is near 600$...
I purchase too a new complete fluke 123 scopmeter, with adequate shunt it make
an always ready Volt and AMP batterie data logger...and can make lots of other
things too :^)
fluke 77 is a very good handy model too, best price/quality you can have i
think.
Philippe
---------- Initial Header -----------
>From : [EMAIL PROTECTED]
To : <[email protected]>
Cc :
Date : Mon, 7 Nov 2005 06:25:08 -0800
Subject : Re: multimeter
Those Fluke 77's are lifetime warrantied - if it's gone belly-up. you should
be able to get it repaired for free!
Joseph H. Strubhar
E-Mail: [EMAIL PROTECTED]
Web: www.gremcoinc.com
----- Original Message -----
From: "Eric Poulsen" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, November 06, 2005 10:44 PM
Subject: Re: multimeter
> Neon John wrote:
>
> >On Sat, 5 Nov 2005 11:58:40 -0800 (PST), Ken Albright
> ><[EMAIL PROTECTED]> wrote:
> >
> >
> >
> >>I beginning to collect tools for my conversion project
> >>(the whole reason for any project, right?). One is the
> >>multimeter. Besides DCV to 2 or 3 decimal places, what
> >>else do I need? Any recommended brands/models?
> >>
> >>
> >
> >There is basically Fluke and the rest of the random data generators.
> >yeah, they're expensive but worth every penny.
> >
> >
> >
> I have to agree with John. I'm in the market for a new multimeter, as
> half the functions on my (15-year-old-was-used-when-I-got-it) Fluke 77
> don't work, including the Amps and the 300mV (fuses are good -- thing is
> just borked).
>
> I spent years repairing test equipment. Most of it was Fluke,
> Tektronics and HP. Guess what I own now? Fluke multimeter, Tektronics
> scope. Haven't (yet) had a need for a counter, wave gen, but when I do,
> it will be one of those brands. Don't bother with the $20 meter you see
> at Sears -- get good equipment.
>
>
------------ ALICE HAUT DEBIT A 29,95 EUR/MOIS ------------
ALICEBOX, l'offre Internet tout en 1 : ADSL, téléphonie, modem Wi-Fi et en
exclusivité
la hotline gratuite 24h/24 ! Soumis à conditions. Pour en profiter cliquez ici
http://abonnement.aliceadsl.fr
--- End Message ---
--- Begin Message ---
Jameco has a Fluke knockoff for under 70 dollars.
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=215589
I bought a 14 dollar cheapie with temp sensor which is within .05 volts.
Cheap is relative. I've had Radio Shack voltmeters which were perfectly
good for testing. What you might do (if you are worried about accuracy)is
get a friend with a fluke or other good multimeter to measure a few
resistors and a battery down to the hundredths. Copy down the readings.&
tape the resistors and battery to the paper and use that for reference. The
battery must be measured imediately. Most batteries lose capacity after
time. (use a aaa battery) Lawrence Rhodes....
--- End Message ---
--- Begin Message ---
In a message dated 11/7/05 7:13:06 AM Pacific Standard Time, [EMAIL PROTECTED]
writes:
<<
Joe Strubhar wrote:
> Those Fluke 77's are lifetime warrantied - if it's gone belly-up. you
should
> be able to get it repaired for free!
>
>
> Joseph H. Strubhar
>
> E-Mail: >>
**I have had my fluke repaired twice in 4 years no questions asked ! Dennis
Berube
--- End Message ---
--- Begin Message ---
Hi haven't seen anybody post the "other " side . I have a fair collection of
meters , the best or most expensive plug's into a computer and can data log
, I almost never use this one , to good to have out working on cars ( got it
from radio shack when they first came out with there data log port ) . The
meter (s) I use almost all the time are the cheep o harror freight which
sometimes go for as little a 3.99 on sale. I bought 10 when they where on
sale and am still learning how to take care of one:-) . I use them to
1 look over a pack voltage , just looking for all batteries to be close to
same voltage , don't need exacta voltage just 2 dismal places 12.34 , 12 40
ohhh 12.12 ,
2 quick check to see if current is flowing . set on millia volt scale and
take voltage down on cable between batteries .
3 set charger , this could be argued , but as there are allot of factors to
this the meter being off a few ten's of a volt don't seem that important .
I'm looking for the nee when the volts starts going up fast .
4 seeing if I have 12 volts to power some aux in the car . here an old
analog meter or light bulb might be better as a dmm doesn't put enough of a
load to tell if you have a good connection .
My be I'm just not careful enough but I seem to go through these meter one
way or another . I don't feel to bad when one gets lost, left in the rain ,
dropped and then run over or when I measure the volts on a battery while the
meter is set on amps .
I have yet to run over one with my electric lawn mower , but the day is not
over :-)
Steve Clunn
I just checked out Flukes. Wow!
Is there nothing that doesn't cost a weeks pay?
Dale Curren
--- End Message ---
--- Begin Message ---
On Monday 07 November 2005 09:29 am, Bob Bath wrote:
> So the way I see it, DCP is a 300W unit. That's 25A
> or so on the 12V line. Headlights, wipers, radio,
> defroster blower. How did it blow a 30A fuse?
25amps in a 30amp fuse will blow it sooner or later. Under ideal conditions, a
fuse must be rated for at least 25% more than the actual current; that means
at least a 31.25amp fuse for a 25amp load.
But this doesn't account for heat, vibration, or currents other than pure DC.
When any of these conditions are present, you need to size the fuse even
bigger or it will still blow. In practice, size a fuse for about twice the
load current; i.e. use a 50amp fuse for a 25amp load to last "forever" (no
nuisance tripping).
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
John wrote:
> What is the benefit of having multiple lesser DVMs in addition to a
> good DVM?
Confucius say: Man with one clock knows what time it is. Man with TWO clocks
isn't sure.
If all you have is one meter, you assume it is accurate. But as soon as you
have two meters, you will realize that they read different values in the same
circuit! They change with temperature, battery condition, when dropped, and
drift over time. Their readings are affected by noise and waveforms in the
circuit.
I have at least a dozen meters around here, and have used a hundred or more in
my life. The ones I can count on to be consistently accurate and "honest" are
my Fluke 8020A, Alfa 2360, and an ancient Simpson 260. All of these happen to
be moderately priced meters; not cheapies, nor are the top-of-the-line
models.
The cheap meters work; they just aren't consistently accurate and reliable.
Use them if you wan't to know *about* what your battery voltage is, not
*exactly* what it is.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
What???
The pots on the front set the float voltage and the "Key On" voltages.
Umm Manual..????
Adjust the darn pots!!! They are labled.
Rich Rudman
----- Original Message -----
From: "OhNoJoe" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Sunday, November 06, 2005 7:30 PM
Subject: DCP DC/DC Converter
> Does any one know how to set the LV and HV limits on a DCP DC/DC
Converter.
> Or does any one have a manual they can email me?
>
> Thanks in advance
>
> Joe
>
--- End Message ---
--- Begin Message ---
Another good alternative is to get a $5 precision voltage reference. Always
perform calibration at a standardized temp.
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 Lawrence Rhodes
Sent: November 7, 2005 7:44 AM
To: [email protected]
Subject: Re: multimeter
Jameco has a Fluke knockoff for under 70 dollars.
http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&sto
reId=10001&catalogId=10001&productId=215589
I bought a 14 dollar cheapie with temp sensor which is within .05 volts.
Cheap is relative. I've had Radio Shack voltmeters which were perfectly
good for testing. What you might do (if you are worried about accuracy)is
get a friend with a fluke or other good multimeter to measure a few
resistors and a battery down to the hundredths. Copy down the readings.&
tape the resistors and battery to the paper and use that for reference. The
battery must be measured imediately. Most batteries lose capacity after
time. (use a aaa battery) Lawrence Rhodes....
--- End Message ---
--- Begin Message ---
If that was the Pacific Northwest Globe Trekker, then that was Travis
Raybold's EV. He is a Portland area EV'r, and he was parked in front of the
one Public Charging station in Portland.
He has been on the list in the past, but I don't know what his current
status is.
damon
From: John David <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: evlist <[email protected]>
Subject: EVs on Globe Trekker
Date: Sun, 6 Nov 2005 18:52:54 -0500
I just saw a show called Globe Trekker and they driefly spotlighted EVs.
Was
that EV guy someone from the list? As they were segueing to the story, just
before the narrator started talking about EVs I saw that the Ford Escort
they were filming had a cord coming out out of it, then they started
talking
about the cool EV parked there, what looked to be a Fiat. Pretty decent
coverage if too brief for me ;-)
John David
www.maxmpg.org <http://www.maxmpg.org>
--- End Message ---
--- Begin Message ---
On Nov 7, 2005, at 5:42 AM, Mark Hanson wrote:
Do any normal vehicles use king pins? I thought all were ball joints
with upper & lower control arms.
The only other common car I'm aware of that uses king pins is the older
VW Beetle (1965 and earlier.) They work well, though the old Beetles
have a pretty antiquated suspension design.
Paul "neon" G.
--- End Message ---
--- Begin Message ---
I've known people who swear by the Simpson 260 -- they're generally
considered to be very very good meters. I think people are kind of down
on them because they're analog.
Lee Hart wrote:
John wrote:
What is the benefit of having multiple lesser DVMs in addition to a
good DVM?
Confucius say: Man with one clock knows what time it is. Man with TWO clocks
isn't sure.
If all you have is one meter, you assume it is accurate. But as soon as you
have two meters, you will realize that they read different values in the same
circuit! They change with temperature, battery condition, when dropped, and
drift over time. Their readings are affected by noise and waveforms in the
circuit.
I have at least a dozen meters around here, and have used a hundred or more in
my life. The ones I can count on to be consistently accurate and "honest" are
my Fluke 8020A, Alfa 2360, and an ancient Simpson 260. All of these happen to
be moderately priced meters; not cheapies, nor are the top-of-the-line
models.
The cheap meters work; they just aren't consistently accurate and reliable.
Use them if you wan't to know *about* what your battery voltage is, not
*exactly* what it is.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
I'm still on the list, though i don't always get to read (or even skim) it.
I park my fiat convertible in front of the world trade center here in
portland, in a very visible spot, with it plugged in. Every other week
or so I get a card or note on it from someone who wants more
information, and I forward them to the oeva.org website. One of those
cards was from the producer of globe trekker, asking if they could film
me with my car. not one to pass up a chance to talk about EVs, I agreed.
They set it up so that the traveller, whose name I forget, would happen
by as I was plugging in, and we chatted for a few minutes. They culled
that down, but still, I think it was pretty good exposure. I've had
people stop me in the streets who recognized me from the show, and a few
friends I haven't seen in years email me.
Someday I'll get organized and have a handout with information about the
car and put it on the side of the car like those real estate flyers at
houses. The parking/charging spots here are great, not just because I
get free parking and charging while at work, but they are very
prominent, so lot's of people notice. I'm sure Rick, who parks in the
other spot here (with that Ford Escort you saw) gets lots of exposure
for us too.
--Travis
damon henry wrote:
If that was the Pacific Northwest Globe Trekker, then that was Travis
Raybold's EV. He is a Portland area EV'r, and he was parked in front
of the one Public Charging station in Portland.
He has been on the list in the past, but I don't know what his current
status is.
damon
From: John David <[EMAIL PROTECTED]>
Reply-To: [email protected]
To: evlist <[email protected]>
Subject: EVs on Globe Trekker
Date: Sun, 6 Nov 2005 18:52:54 -0500
I just saw a show called Globe Trekker and they driefly spotlighted
EVs. Was
that EV guy someone from the list? As they were segueing to the
story, just
before the narrator started talking about EVs I saw that the Ford Escort
they were filming had a cord coming out out of it, then they started
talking
about the cool EV parked there, what looked to be a Fiat. Pretty decent
coverage if too brief for me ;-)
John David
www.maxmpg.org <http://www.maxmpg.org>
.
smime.p7s
Description: S/MIME Cryptographic Signature
--- End Message ---
--- Begin Message ---
Just a heads up to any of you looking to build a better charger or
battery management setup... or just for those who like to understand the
principles behind what they are using :)
There are still a few dates for the $99 (you get to keep the prototyping
hardware!) hands-on seminars on Portable Power Management Solutions from
MicroChip. The description is:
Register for this session if:
You are currently using battery management applications and
are looking for new solutions and feature sets
You are thinking about incorporating battery charging designs
into your applications or want more background in battery
chemistries
What you will learn:
Battery chemistry performance trade-offs
Efficient energy removal techniques
How to effectively restore energy to rechargeable batteries
Agenda:
Battery Basics
Efficiently Transferring Battery Energy to the System Load
Systematic Approach to Designing a Charging System
This is the afternoon class; the morning class, which is free, (Beginner
- Introductory Embedded Control Solutions) would help with understanding
the background stuff for the non-engineers with a bit of electronics
experience.
The announcement with dates is in the current newsletter, page 6:
http://techtrain.microchip.com/seminars/LHC/HCApp.aspx?ID=335
Have fun!
~ Proud owner of a 1968 Datsun 2000 Roadster EV, still in the early stages ~
--- End Message ---
--- Begin Message ---
On Monday 07 November 2005 10:29 am, you wrote:
Lee Hart wrote:
>> To transfer a lot of heat to air, you need a large
>> surface area and/or a large volume of airflow. The
>> surface area and airflow needed are *not affected*
>> by whether you use water or not!
Fortunat Mueller replied:
> I don't think the above statement is absolutely true.
>
> If you fix the quantity of heat to be rejected, the
> temperature of the source, and the temperature of the
> sink, then adding an additional heat transfer step
> (water cooling) will increase either the size or
> airflow required for the final radiator.
This illustrates the problem that people had before Ohm's Law. Their
instruments (voltmeters, ammeters) drew significant power, and so affected
the circuit they were trying to measure. So the apparent resistance of a
circuit appeared to change in an unpredictable matter.
We have the same problem with heat. We don't have accurate heat "voltmeters"
or "ammeters", so our measurements of thermal "resistance" are often
inaccurate and lead us to false conclusions.
But ideally, we do have an Ohm's Law for heat;
deltaT = Q x R
where deltaT = temperature difference between heat source and ambient air
(in degrees C)
Q = the amount of heat you need to dump (in watts)
R = the thermal resistance between the heat source and ambient air
(in degrees C per watt)
The challenge is to measure any of these parameters accurately!
Q isn't too bad, because we can measure it electrically. For example, we can
tell that a transistor has 3 volts across it and is carrying 100 amps;
therefore it is producing 3v x 100a = 300 watts of heat.
deltaT is tough because we can't get a thermometer right on the transistor
junction itself; it's hidden inside the case. We can measure our ambient air
temperature, except that the air temperature around our heatsink will
necessarily increase as a consequence of dumping heat into it. So at best we
can approximate these two number; we might say the transistor junction
temperature is 100 deg.C and our air temperature is 25 deg.C, so deltaT =
100-25 = 75 deg.C.
R is really messy! It's actually a whole series of smaller resistors,
connected in an awkward series-parallel network. There's one from transistor
junction to its case; another from case to heatsink, another within the
heatsink from the transistor mounting surface to the fins, and yet another
from the fins to the air. In addition, there are "sideways" resistances
directly to the air from the transistor case, heatsink mounting surface, and
every other piece to the air. You have to total up this whole mess to
estimate the total equivalent thermal resistance.
When you add water cooling, you're just adding more thermal resistors to this
mess. Just like with electrical resistors, adding thermal resistors in series
increases the total resistance (makes things worse); adding them in parallel
decreases the total resistance (makes it better).
Now for my key point. If you have a fixed amount of heat to move (Q), and a
fixed temperature difference (deltaT), then all that matters is the value of
R. It doesn't make any difference *how* you get that value R; with or without
water.
Your comment acutally agrees with this. If water cooling *adds* a thermal
resistance between transistor and heatsink/radiator, you've made the total R
bigger. To get it back down, you have to make the heatsink/radiator bigger,
or blow more air through it, or both.
But if water cooling creates a parallel path for the heatflow, so you're
*decreasing* the total R, then you can let the R of the heatsink/radiator
increase a bit; it can be smaller, or needs less air.
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 [EMAIL PROTECTED]
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--- Begin Message ---
Ryan,
most, if not all, or the PEM fuel cells used in
automotive applications have some platinum or other
precious metal catalyst. However the cost of the PT in
these fuel cells is a tiny fraction of the cost of
these power plants. Today's typical automotive fuel
cell powerplant has probably about 2 oz of pt (down
from about 20 oz 10 years ago and heading towards a
target of 0.2 oz for a production unit). While that
isn't cheap, the material cost is on the order of
hundreds of dollars, not tens or hundreds of thousands
of dollars.
> What else is them that can cost so much?
speaking generically for PEM fuel cells, the highest
cost portions are:
labor - most fuel cells are still assembled by hand
polymer membranes : made in small qty by only a couple
companies.
Machined flow fields: made in relatively small qty
with extremely high machining cost and scrap rates
Balance of plant : mostly custom welded assemblies
made of expensive metals like 316L SS along with
custom components made in low quantities with strange
(by automotive standards) requirements.
and design : high initial design costs amortized over
a small number of units.
in short, everything costs a lot because it is new and
the volumes are low. Anyone who says fuel cells are
expensive mostly because of the cost of PT, doesn't
really know what they are talking about.
~fortunat
--- Ryan Stotts <[EMAIL PROTECTED]> wrote:
> gail donaldson lucas wrote:
>
> > When the fuel cells become available at a lower
> cost
>
> Are they still using platinum in the hydrogen fuel
> cells? I don't see
> how the price will come down as long as they are
> using platinum. What
> else is them that can cost so much?
>
>
__________________________________
Start your day with Yahoo! - Make it your home page!
http://www.yahoo.com/r/hs
--- End Message ---
--- Begin Message ---
Bob Bath wrote:
> the 12V line. Headlights, wipers, radio,
> How did it blow a 30A fuse?
defroster blower.
Put a meter on that blower and see how many amps it pulls at various
speeds. Also, how many amps do your headlights pull? What about that
wiper motor? Radio? Brake lights and turn signals?
It would be interesting to know just for reference how much total all
that stuff pulls.
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--- Begin Message ---
Jacob,
Remove the 9 pin plug from the controller and short pins 2 and 3
together on your RS 232 plug. Then, type some stuff on your keyboard.
It should appear on your screen. This will prove that your rec connection
is good and that your program is ok. I used ansi emulation on hyperterminal
and I think that this is the default, but you might want to check this also.
----- Original Message -----
From: "Evan Tuer" <[EMAIL PROTECTED]>
To: <[email protected]>
Sent: Monday, October 31, 2005 10:57 AM
Subject: Re: Solectria controller connecting w/PC (Hyperterminal)
> Have you set your terminal program to "no handshaking". Otherwise, if
> the solectria interface is 3 wire (or your cable is), you might not
> actually be transmitting.
>
> Worth a try maybe!
>
> Regards
> Evan
>
> On 10/31/05, Jacob <[EMAIL PROTECTED]> wrote:
> > I'm having trouble connecting my UMOC controller to my PC. I'm trying to
> > access the parameters. I've gotten to the "banner" where it shows
"Solectria
> > UMOC 340, (the production date), and config # (v.1.2 is default and not
> > written). But then you're supposed to press 'enter' twice, type in
password,
> > if any (and I was told by some one else who's done this that a password
> > wasn't needed), and press 'enter' again, and the main screen should
appear.
> > But nothing happens after the banner. Anyone have any clues?
> >
> > Jacob Harris
> > Solectria E-10
> >
> >
>
>
--- End Message ---
--- Begin Message ---
On Mon, 7 Nov 2005 08:50:57 -0500, "STEVE CLUNN"
<[EMAIL PROTECTED]> wrote:
>
>
>Hi haven't seen anybody post the "other " side . I have a fair collection of
>meters , the best or most expensive plug's into a computer and can data log
>, I almost never use this one , to good to have out working on cars ( got it
>from radio shack when they first came out with there data log port ) . The
>meter (s) I use almost all the time are the cheep o harror freight which
>sometimes go for as little a 3.99 on sale. I bought 10 when they where on
>sale and am still learning how to take care of one:-) . I use them to
>1 look over a pack voltage , just looking for all batteries to be close to
>same voltage , don't need exacta voltage just 2 dismal places 12.34 , 12 40
>ohhh 12.12 ,
>2 quick check to see if current is flowing . set on millia volt scale and
>take voltage down on cable between batteries .
A little story about that. I bought a bunch of those chicom meters at
oh, $5 apiece, I think. My thinking was that I could trim them in
against my Fluke calibrator to read correctly on volts and then toss
one in each of my vehicles for roadside emergencies.
Fast-forward a bit. I head out in my MH for my Christmas vacation. I
made the mistake of not fully charging my house batteries before
leaving and the combined load of charging them and running the
headlights smoked my alternator (now replaced with a truck
alternator). I cranked the genny and let the house 12 volt converter
supply the engine and lights for the through-the-night drive.
On Christmas Eve I stopped at a NAPA and got a new alternator. I was
planning on touring the museum at NAS Norfolk so I pulled into the
base parking and took the tour and the museum. Then, with it spitting
snow, I changed the alternator in the parking lot, freezing my butt
off. I cranked the engine and saw only about 11.5 volts on the
battery.
Bitch!!! Another bad reman. I got the security outfit to let me
spend the night in the museum parking lot, spent Christmas day in the
parking lot and also that night. Great Christmas, eh. I drove back
to the NAPA the day after and changed the alternator. I changed it
out in the NAPA parking lot, again freezing my butt off.
Again, 11.5 volts with the engine running. Not believing I could get
two bad alternators in a row, I started looking at this ChiCom meter.
I went back in and talked to the counter dude. Turns out he had a low
end Fluke in his personal tool box. He got it out and we checked the
battery. 14.0 volts with the engine running. ChiCom meter - 11.5.
I'd checked the meter before I put it in the rig and it was correct
within a tenth of a volt.
Resisting the urge to hurl the meter, I thanked the NAPA dude and took
the meter inside, thinking I'd look at it to see what was wrong. That
night when we got to the Outer Banks and stopped, I got the meter out
and checked the voltage on a cig lighter outlet in the rig. 13.8
volts, exactly what it should read with the generator on and the
converter supplying power. After thinking about it for a moment, I
put the meter in the RV freezer and left it for an hour. 11.3 volts.
This time I hurled the damned thing and was satisfied to see it
spontaneously disassemble into a meter kit :-)
I've never seen an instrument suffer that much thermal effect but this
one did. It could have been a temperature sensitive component or it
could be battery voltage sensitive and responded to the battery's
lower voltage when cold. I don't know since it had been rendered back
into kit form :-)
The other meters showed similar but smaller tempco's when I checked
them after returning home. They ALL went in the garbage. It's taken
me awhile to accumulate enough used Flukes from hamfests and the like
to fit out all my vehicles but I finally have.
By saving a very few dollars, I bought myself a screwed up Christmas,
two alternator changes under miserable conditions and several busted
knuckles.
It's just not worth the uncertainty to buy cheap when used Flukes are
so affordable.
I should comment about one other thing. Since Fluke and Philips
instruments became incestuous (detect a little contempt there for
Philips stuff?) Fluke has IMHO sullied their reputation by labeling
some low end Philips stuff with the Fluke name. The low end stuff
sold at MRO, HVAC parts outfits and the like come to mind. Sears
carries some of the low end Flukes. While VASTLY better than the
ChiCom junk, these instruments aren't the DVMs-for-life that the
better ones are.
I still have the first Fluke LCD display meter I ever bought back in
the 70s. 8060 I think is the model. It looks like it's been through
a garbage disposal and I've had to replace the LCD once after it baked
off in my car in south Texas one summer but it still exceeds its
specs. My primary bench meter is an 8800, a 5.5 digit meter of 70s
vintage that also meets its specs. I can't calibrate this one, as its
specs are about equal to my calibrator but I can make sure they agree
down to the LSD and I do send it off every so often for a calibration
check. I see these 8800s at hamfests all the time for under $40. It
was about $2000 when new.
Other than the price, the thing I like about these old meters is that
they're through the drift that comes with new components. Fluke
aged-in the zener reference, op-amp and resistors that make up the
reference section but everything still drifts a little when new. With
20 years under its belt, an 8800 or something similar has all that
drift behind it. It will remain rock-solid until something like an
electrolytic cap in the power supply has to be changed. That can be
changed out without affecting the calibration.
I've acquired more than one 8800 as junk because of a power supply
problem. Ripple in the PX makes the display scramble and the
auto-range relays chatter, making one think the blue smoke is about to
leak out :-) Change out one or two electrolytics and the unit is good
as new.
John
---
John De Armond
See my website for my current email address
http://www.johngsbbq.com
Cleveland, Occupied TN
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