I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing about
this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

Thanks guys,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

jeff_wisnia wrote:

I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The only issue should be the cooling fan. If it spins the wrong way, it
won't cool anything.

On May 4, 3:09 pm, Cydrome Leader wrote:
jeff_wisnia wrote:

I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The only issue should be the cooling fan. If it spins the wrong way, it
won't cool anything.

I built an inboard boat. Chev 283. The alternator hung off one
side too far, interfering with the sidewalls of the compartment, so I
made a new bracket and turned the alternator around, facing the engine
and closer to centerline. The angled-blade fan I replaced with a
straight-blade fan (blades directly radiating from shaft) from the
junkyard, some cars had them and it doesn't matter which way they
turn. That alternator ran for hundreds of hours before I sold the
boat. The brushes in all the alternators I've had apart point straight
at the shaft and they don't care about rotation unless they're badly
worn and the holder has let them cock and wear at an angle. The output
will be the same in either direction.

If the battery is totally dead the alternator won't pick it up.
Its rotor won't hold enough magnetism to generate enough voltage to
overcome the diode drops, especially if there's any load present, as
there always is. Leaned this the hard way, towing a dead truck to try
to start it. Engine turned merrily but would not fire. Had to jump it.
Generators, on the other hand, have field pole shoes that will carry
enough flux to bootstrap the system. No diodes there.

In about 1977 I bought, for $27.95, a black box that, once wired
into my pickup, would generate 110VDC for series-wound power tools and
the like. Before I put it in I took it apart to see what I had paid
$28 for. It was: One plastic box; one 110VAC household duplex outlet;
one DPDT toggle switch, one neon lamp assembly (NE-2H, IIRC), and one
resistor of something like 33K. Total cost in those days of about $4.
The outlet was wired through one pole of the DPDT switch to the
alternator output. The other throw of the same pole went to the
battery +. The other pole of that switch simply switched the
alternator's field between the regulator and the battery +. The neon
assembly, with its suitable resistor to make it fire at 110V, was
across the duplex outlet's terminals. So with the switch "off,
everything worked normally. With it "on," the field got full battery
voltage and the alternator's output, freed of the battery via the
switch, generated increasing voltage as the throttle was opened until
the light lit up and you wnt to work for ten of 15 minutes, then
switched back to normal for a minute or so to recharge the battery.
The diodes in the alternator took this for as long as I had the truck.
My only peeve with it was being hosed so badly for a handful of
cheap parts. No magic in that box at all. Disappointing. $28 in 1978
was worth something. I could rent an airplane for an hour for not much
more than that.

Dan

jeff_wisnia writes:


I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The wear on the slip ring brushes may be different.

And I agree with your thinking as to the Puzzler.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

jeff_wisnia writes:

I'm thinking that all else left alone, it probably doesn't matter
which way the shaft of an automobile alternator is rotated since the
machine produces ac which is then rectified to create a polarized dc
output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing
about this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

My drill is reversible, so it doesn't really matter anyway...

Joe Pfeiffer wrote:
jeff_wisnia writes:


I'm thinking that all else left alone, it probably doesn't matter
which way the shaft of an automobile alternator is rotated since the
machine produces ac which is then rectified to create a polarized dc
output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing
about this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html


My drill is reversible, so it doesn't really matter anyway...


And all my 120 volt drills turn only CW. (That tells ya
how olde they (and I) am. G

Son just pinged me to say that if you ran the alternator belt over the
alternator pulley and then over the drill chuck you could point the
drill in the appropriate direction. That may be the answer the Car Talk
guys are looking for, as it's not likely there'd be enough room under
the hood to connect the drill through a socket directly to the
alternator shaft nut.

But, you could always unmount the alternator and.......

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

"jeff_wisnia" wrote in message
eonecommunications...
Joe Pfeiffer wrote:
jeff_wisnia writes:


I'm thinking that all else left alone, it probably doesn't matter
which way the shaft of an automobile alternator is rotated since the
machine produces ac which is then rectified to create a polarized dc
output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing
about this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html


My drill is reversible, so it doesn't really matter anyway...


And all my 120 volt drills turn only CW. (That tells ya
how olde they (and I) am. G

Son just pinged me to say that if you ran the alternator belt over the
alternator pulley and then over the drill chuck you could point the drill
in the appropriate direction. That may be the answer the Car Talk guys are
looking for, as it's not likely there'd be enough room under the hood to
connect the drill through a socket directly to the alternator shaft nut.

But, you could always unmount the alternator and.......

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

I may be splitting hairs here, doesn't the battery have to have a little bit
of charge in order for the alsternator to be excited enought to generate?

"Nutz" writes:


I may be splitting hairs here, doesn't the battery have to have a little bit
of charge in order for the alsternator to be excited enought to generate?

Maybe. But often the soft iron contains enough flux to self-excite. And a
""dead"" battery isn't usually. Turn off the headlights, wait 10 minutes,
and you'll likely get several volts out...

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"Nutz" writes:

I may be splitting hairs here, doesn't the battery have to have a little bit
of charge in order for the alsternator to be excited enought to generate?

You don't have enough power to turn the engine over (and will refer to
the battery as "dead") a long, long time before the juice is too low to
run the alternator.

The part of the problem I'm wondering about is getting the belt back on,
and tight enough to turn the alternator, with the engine running. Or
else you better live pretty close..

Joe Pfeiffer writes:


The part of the problem I'm wondering about is getting the belt back on,
and tight enough to turn the alternator, with the engine running. Or
else you better live pretty close..

Never happen.... Charge battery; replace belt, and hope it will start.
If not, yank belt, and charge 3x as long, try again.

I've tried to think up a belt-unloading scheme using the extra-virgin
olive oil, to no success....

I might UNPLUG the alternator while cranking; to remove that load from
the system...





--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

On 2009-05-05, Joe Pfeiffer wrote:
"Nutz" writes:

I may be splitting hairs here, doesn't the battery have to have a little bit
of charge in order for the alsternator to be excited enought to generate?

You don't have enough power to turn the engine over (and will refer to
the battery as "dead") a long, long time before the juice is too low to
run the alternator.

The part of the problem I'm wondering about is getting the belt back on,
and tight enough to turn the alternator, with the engine running. Or
else you better live pretty close..

You could also disassemble the alternator and wire the AC from
the gas powered generator to two of the phases of the three phase bridge
in the alternator and use that to charge the battery. The alternator
with no load can produce 120 VAC 3 phase, so the diode bridge should be
rated to handle that much voltage.

Or perhaps the generator may even have a battery start in which
case it will have DC to charge its own battery and that could be wired
to the car's battery as well -- assuming that both are 12V batteries.

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On Tue, 5 May 2009 10:03:41 +0800, the infamous "Nutz"
scrawled the following:

I may be splitting hairs here, doesn't the battery have to have a little bit
of charge in order for the alsternator to be excited enought to generate?

It would. Lead acids tend to rebuild naturally after the load is
removed, and lights left on would probably only pulled it down to 8v
or so, plenty for excitation of the silicon bits.

--
The scientific theory I like best is that the rings of Saturn
are composed entirely of lost airline luggage.
--Mark Russell

jeff_wisnia wrote:

Joe Pfeiffer wrote:
jeff_wisnia writes:


I'm thinking that all else left alone, it probably doesn't matter
which way the shaft of an automobile alternator is rotated since the
machine produces ac which is then rectified to create a polarized dc
output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing
about this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html


My drill is reversible, so it doesn't really matter anyway...

And all my 120 volt drills turn only CW. (That tells ya
how olde they (and I) am. G

Son just pinged me to say that if you ran the alternator belt over the
alternator pulley and then over the drill chuck you could point the
drill in the appropriate direction. That may be the answer the Car Talk
guys are looking for, as it's not likely there'd be enough room under
the hood to connect the drill through a socket directly to the
alternator shaft nut.

But, you could always unmount the alternator and.......

I wonder if hat's the correct approach. In my cars, the alternator
pulley ratio apears to be at least 3:1. So at idle, the alternator is
spinning at around 2400 RPM. My drill won't do anywhere near that speed.
And running the belt over the chuck will turn the alternator pulley
slower than the drill.

I'd just take the extension cord and/or jumper cables and wire the
generator in series with the alternator output. The alternator diodes
will rectify the AC. Then, throttle the generator up slowly. At a low
RPM, its voltage output will be low enough to charge the battery.

--
Paul Hovnanian
------------------------------------------------------------------
Porsche 928: 0 to c in 2.125 years, 2.435 light-years per mile^3 of gas

Paul Hovnanian P.E. wrote:
jeff_wisnia wrote:

Joe Pfeiffer wrote:

jeff_wisnia writes:



I'm thinking that all else left alone, it probably doesn't matter
which way the shaft of an automobile alternator is rotated since the
machine produces ac which is then rectified to create a polarized dc
output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing
about this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html


My drill is reversible, so it doesn't really matter anyway...

And all my 120 volt drills turn only CW. (That tells ya
how olde they (and I) am. G

Son just pinged me to say that if you ran the alternator belt over the
alternator pulley and then over the drill chuck you could point the
drill in the appropriate direction. That may be the answer the Car Talk
guys are looking for, as it's not likely there'd be enough room under
the hood to connect the drill through a socket directly to the
alternator shaft nut.

But, you could always unmount the alternator and.......


I wonder if hat's the correct approach. In my cars, the alternator
pulley ratio apears to be at least 3:1. So at idle, the alternator is
spinning at around 2400 RPM. My drill won't do anywhere near that speed.
And running the belt over the chuck will turn the alternator pulley
slower than the drill.

That's what I said to my son, but his immediate reply was, "So...wrap
that whole roll of duct tape around the drill chuck to increase its
diameter."

I'd just take the extension cord and/or jumper cables and wire the
generator in series with the alternator output. The alternator diodes
will rectify the AC. Then, throttle the generator up slowly. At a low
RPM, its voltage output will be low enough to charge the battery.


Yeah, that should work too, and I'd expect the alternator diodes would
have a high enough reverse breakdown rating to be able to stand someone
doing that, but what if I'm wrong??? G

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

jeff_wisnia writes:

My drill is reversible, so it doesn't really matter anyway...


And all my 120 volt drills turn only CW. (That tells ya
how olde they (and I) am. G

Son just pinged me to say that if you ran the alternator belt over the
alternator pulley and then over the drill chuck you could point the
drill in the appropriate direction. That may be the answer the Car Talk
guys are looking for, as it's not likely there'd be enough room under
the hood to connect the drill through a socket directly to the
alternator shaft nut.

But, you could always unmount the alternator and.......


My answer is first look for a DC output from the generator. Many
have them.

Either direction will do; with the hood open and the engine
off the generator will be in a far cooler enviroment.

I wonder how hard you can push it anyhow. A 100A car alternator
is outputting ~1.5KW. [15v*100A] It needs say 2KW in to deliver
that. That means the drill would need to produce 2KW. It would
draw say 2600 watts. Can YOUR drill produce that? For how long?
(I think it more likely you can get 600 watts ergo 20A out.)

So I think it fair to say that while you can spin the alternator
and get some charge out of it; it's going to take you a while.

The other question is how to connect it up. Given we have a roll of
duct tape... wrap the pulley and the chuck in same; and use friction
drive? If it's a flat belt, you could drive it from the chuck...maybe.



--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

jeff_wisnia wrote:

Joe Pfeiffer wrote:

jeff_wisnia writes:


I'm thinking that all else left alone, it probably doesn't matter
which way the shaft of an automobile alternator is rotated since the
machine produces ac which is then rectified to create a polarized dc
output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing
about this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html



My drill is reversible, so it doesn't really matter anyway...



And all my 120 volt drills turn only CW. (That tells ya
how olde they (and I) am. G

Son just pinged me to say that if you ran the alternator belt over the
alternator pulley and then over the drill chuck you could point the
drill in the appropriate direction. That may be the answer the Car Talk
guys are looking for, as it's not likely there'd be enough room under
the hood to connect the drill through a socket directly to the
alternator shaft nut.

But, you could always unmount the alternator and.......

Jeff



The "official answer" from the Car Talk boys is:

http://www.cartalk.com/content/puzzl...18/answer.html

But I do have trouble buying it, there just can't be very many vehicles
around with enough physical space in front of the alternator pulley to
cram a typical 120 volt electric drill into.

But maybe I don't know where the "chock" is on a drill. G

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

On Mon, 11 May 2009 18:05:09 -0400, jeff_wisnia
wrote:

jeff_wisnia wrote:

Joe Pfeiffer wrote:

jeff_wisnia writes:


I'm thinking that all else left alone, it probably doesn't matter
which way the shaft of an automobile alternator is rotated since the
machine produces ac which is then rectified to create a polarized dc
output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing
about this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html



My drill is reversible, so it doesn't really matter anyway...



And all my 120 volt drills turn only CW. (That tells ya
how olde they (and I) am. G

Son just pinged me to say that if you ran the alternator belt over the
alternator pulley and then over the drill chuck you could point the
drill in the appropriate direction. That may be the answer the Car Talk
guys are looking for, as it's not likely there'd be enough room under
the hood to connect the drill through a socket directly to the
alternator shaft nut.

But, you could always unmount the alternator and.......

Jeff



The "official answer" from the Car Talk boys is:

http://www.cartalk.com/content/puzzl...18/answer.html

But I do have trouble buying it, there just can't be very many vehicles
around with enough physical space in front of the alternator pulley to
cram a typical 120 volt electric drill into.

But maybe I don't know where the "chock" is on a drill. G

Jeff
Click and Clack are idiots anyway.

wrote:
On Mon, 11 May 2009 18:05:09 -0400, jeff_wisnia
wrote:


jeff_wisnia wrote:


Joe Pfeiffer wrote:


jeff_wisnia writes:



I'm thinking that all else left alone, it probably doesn't matter
which way the shaft of an automobile alternator is rotated since the
machine produces ac which is then rectified to create a polarized dc
output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing
about this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html



My drill is reversible, so it doesn't really matter anyway...



And all my 120 volt drills turn only CW. (That tells ya
how olde they (and I) am. G

Son just pinged me to say that if you ran the alternator belt over the
alternator pulley and then over the drill chuck you could point the
drill in the appropriate direction. That may be the answer the Car Talk
guys are looking for, as it's not likely there'd be enough room under
the hood to connect the drill through a socket directly to the
alternator shaft nut.

But, you could always unmount the alternator and.......

Jeff



The "official answer" from the Car Talk boys is:

http://www.cartalk.com/content/puzzl...18/answer.html

But I do have trouble buying it, there just can't be very many vehicles
around with enough physical space in front of the alternator pulley to
cram a typical 120 volt electric drill into.

But maybe I don't know where the "chock" is on a drill. G

Jeff

Click and Clack are idiots anyway.


I can't agree with that statement, Claire.

They are merely playing to the level of their current radio audience,
and their show has remained on the air for over 30 years now.

Both of them graduated of my alma mater a few years after I did and in
1999 that school (MIT) honored them by having them as that years's
commencement speakers.

I've met them both a few times in a non-radio show setting and they sure
didn't sound like idiots to me.

And I still get a chuckle if I'm in Harvard Square, Cambridge and see
"Dewey Cheetham and Howe" on that office window

http://image07.webshots.com/7/0/25/8...3kDHlbw_fs.jpg
Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

On Mon, 04 May 2009 16:46:10 -0400, the infamous jeff_wisnia
scrawled the following:


I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

Electrically, you're probably right. But the brushes I've seen during
rebuilds of most brands (in my previous life) were usually situated to
run in one direction only and they'd self-destruct in minutes if run
the opposite direction.


The question came up just now when eldest son and I were kibitzing about
this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

"Some kind of builder" wasn't very bright, was he?

I'd run the genset to power up the drill to turn the alternator to
charge the battery, even if I had to drill a hole through the radiator
support and/or grille to do it with a branch extension and the duct
tape.

--
The scientific theory I like best is that the rings of Saturn
are composed entirely of lost airline luggage.
--Mark Russell

On Mon, 04 May 2009 16:46:10 -0400, jeff_wisnia
wrote:


I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing about
this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

Thanks guys,

Jeff

So he's gonna build a cabin with an electric drill and a socket
wrench? Must be an erector set scaled up, or maybe a metal pole
building. Not what I visualize when I think "cabin", but these are
modern times.

Joe

On Tue, 05 May 2009 09:12:42 -0400, the infamous Joe
scrawled the following:

On Mon, 04 May 2009 16:46:10 -0400, jeff_wisnia
wrote:


I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing about
this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

Thanks guys,

Jeff

So he's gonna build a cabin with an electric drill and a socket
wrench?

They forgot to mention his hammah, nailbag, and handsaw.


Must be an erector set scaled up, or maybe a metal pole
building. Not what I visualize when I think "cabin", but these are
modern times.

Look what they refer to as cabins he
http://www.precisioncraft.com/loghom...k/Caribou.html
http://www.precisioncraft.com/loghom...n/Targhee.html
http://imaginactive.typepad.com/phot...log_home_2.jpg
http://www.cedar-log-homes.com/log-home-pictures.htm

Disgusting, isn't it?

--
The scientific theory I like best is that the rings of Saturn
are composed entirely of lost airline luggage.
--Mark Russell

On Tue, 05 May 2009 07:07:14 -0700, Larry Jaques
wrote:

On Tue, 05 May 2009 09:12:42 -0400, the infamous Joe
scrawled the following:


So he's gonna build a cabin with an electric drill and a socket
wrench?

They forgot to mention his hammah, nailbag, and handsaw.


Must be an erector set scaled up, or maybe a metal pole
building. Not what I visualize when I think "cabin", but these are
modern times.

Look what they refer to as cabins he
http://www.precisioncraft.com/loghom...k/Caribou.html
http://www.precisioncraft.com/loghom...n/Targhee.html
http://imaginactive.typepad.com/phot...log_home_2.jpg
http://www.cedar-log-homes.com/log-home-pictures.htm

Disgusting, isn't it?

Umm, "rustic", "cozy", "quaint", "charming"... Oh hell, you're right -
"disgusting".

Joe

Joe wrote:

On Tue, 05 May 2009 07:07:14 -0700, Larry Jaques
wrote:

On Tue, 05 May 2009 09:12:42 -0400, the infamous Joe
scrawled the following:


So he's gonna build a cabin with an electric drill and a socket
wrench?

They forgot to mention his hammah, nailbag, and handsaw.


Must be an erector set scaled up, or maybe a metal pole
building. Not what I visualize when I think "cabin", but these are
modern times.

Look what they refer to as cabins he
http://www.precisioncraft.com/loghom...k/Caribou.html
http://www.precisioncraft.com/loghom...n/Targhee.html
http://imaginactive.typepad.com/phot...log_home_2.jpg
http://www.cedar-log-homes.com/log-home-pictures.htm

Disgusting, isn't it?

Umm, "rustic", "cozy", "quaint", "charming"... Oh hell, you're right -
"disgusting".

Joe


http://www.loghome.com/hunting_cabin/articles/2536 How do you like
this cabin?


--
You can't have a sense of humor, if you have no sense!

On Mon, 04 May 2009 16:46:10 -0400, jeff_wisnia
wrote:


I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing about
this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

Thanks guys,

Jeff

If that is the current puzzler it has been recycled (not
like Ray would do something like that

The answer as I remember it was to use the generator to run
the drill to turn the alternator. I think they slipped the
belt off and looped it over the drill chuck.

As normal, I doubt if anyone actually tried to do this, but
in theory it should work, eventually...

--
Leon Fisk
Grand Rapids MI/Zone 5b
Remove no.spam for email

1.I don't think the drill would get you any significant output. The
diameter of the drill chuck is only 1 1/2" or so. The vehicle's
crankshast pulley is a LOT bigger and the car engine would have to be
running at 400 or 500 rpms or so to do the job.
Maybe the use for the duct tape is to wrap around the chuck until it
gets big enough to do the job. But I think that would take several rolls.

2. If I was in that situation, I'd consider taking the alternator (or
something else in the vacinity) apart to get a diode. Then I'd slow the
generator down a lot and use it to directly, (now outputing a much lower
voltage, half wave rectified) charge the battery. The duct tape could
be used to keep me from getting zapped. I think.

3.On the other hand, depending on the weather and the voltage the of
battery pack in the "radio" one might be able to use its batteries to
trickle charge the car for one start. If the "radio" was one of those
contractors models, it might take a 12, 18 or even higher voltage plug
in battery pack.

4.Okay---- Here it is: The "radio" has a built in charger for it's own
battery. Just plug the thing in to the generator, and with a little
judicious rewiring, use that charger to bring the car's battery back to
life. Pour the olive oil out around the car, so wild animals will slip
and fall down before they can attack you while you are getting things going.

Pete Stanaitis

spaco wrote:

[snip]

2. If I was in that situation, I'd consider taking the alternator (or
something else in the vacinity) apart to get a diode. Then I'd slow the
generator down a lot and use it to directly, (now outputing a much lower
voltage, half wave rectified) charge the battery. The duct tape could
be used to keep me from getting zapped. I think.

You don't actually have to take the alternator apart to use its diodes.
Just remove the alternator output terminal and connect the generator AC
output in series with the alternator positive output stud and the wire
leading to the battery. Then, as you suggested, throttle the generator
down to reduce its output voltage.

--
Paul Hovnanian
------------------------------------------------------------------
Why are so many towns named after water towers?

"Paul Hovnanian P.E." writes:


You don't actually have to take the alternator apart to use its diodes.
Just remove the alternator output terminal and connect the generator AC
output in series with the alternator positive output stud and the wire
leading to the battery. Then, as you suggested, throttle the generator
down to reduce its output voltage.

I think you'll kill the alternator diodes very quickly with this
stunt. What do you think their PIV rating is?

And then WTH will you do?

If you insist; then disconnect the battery from the car, and run a wire
to the positive terminal from the generator. The battery can withstand
short overvoltages far better than anything else in the car. Watch out
for ground loops.

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

On Wed, 6 May 2009 17:07:15 +0000 (UTC), David Lesher
wrote:

"Paul Hovnanian P.E." writes:


You don't actually have to take the alternator apart to use its diodes.
Just remove the alternator output terminal and connect the generator AC
output in series with the alternator positive output stud and the wire
leading to the battery. Then, as you suggested, throttle the generator
down to reduce its output voltage.

I think you'll kill the alternator diodes very quickly with this
stunt. What do you think their PIV rating is?


Older Delcotron alternator diodes were 250PIV
And then WTH will you do?

If you insist; then disconnect the battery from the car, and run a wire
to the positive terminal from the generator. The battery can withstand
short overvoltages far better than anything else in the car. Watch out
for ground loops.

writes:

I think you'll kill the alternator diodes very quickly with this
stunt. What do you think their PIV rating is?


Older Delcotron alternator diodes were 250PIV

And 120RMS has a peak-to-peak of........


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

David Lesher wrote:

"Paul Hovnanian P.E." writes:

You don't actually have to take the alternator apart to use its diodes.
Just remove the alternator output terminal and connect the generator AC
output in series with the alternator positive output stud and the wire
leading to the battery. Then, as you suggested, throttle the generator
down to reduce its output voltage.

I think you'll kill the alternator diodes very quickly with this
stunt. What do you think their PIV rating is?

And then WTH will you do?

You run the throttle up slowly until the alternator warning light goes
out, then stop.

If you insist; then disconnect the battery from the car, and run a wire
to the positive terminal from the generator. The battery can withstand
short overvoltages far better than anything else in the car. Watch out
for ground loops.

What positive terminal? We're assuming that its a 120 VAC only unit (or
the answer would be trivial).

--
Paul Hovnanian
------------------------------------------------------------------
The only tools one needs in life:
WD-40 to make things go and duct tape to make them stop.

"Paul Hovnanian P.E." writes:

If you insist; then disconnect the battery from the car, and run a wire
to the positive terminal from the generator. The battery can withstand
short overvoltages far better than anything else in the car. Watch out
for ground loops.

What positive terminal? We're assuming that its a 120 VAC only unit (or
the answer would be trivial).

The BATTERY positive.....


ALT+ ------Gen "Neutral" Gen "Hot"----------------------+ BAT term.



--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"Paul Hovnanian P.E." writes:


You run the throttle up slowly until the alternator warning light goes
out, then stop.

I can't picture how putting any voltage on the ALT terminal will do that.
It normally has 13.8 from the battery any time.

Plus, as I said, if I was risking what you propose; I'd isolate the
system from the car by a) disconnecting the battery terminal and feeding
the battery directly. b) Disconnecting the Alt field connections.

I might put one of the headlamps in series with the battery. That gives
you a current limit and monitor.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

On May 4, 3:46*pm, jeff_wisnia wrote:
I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing about
this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

Thanks guys,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

A former poster on this group....
Told a tale of parking his car Many miles into the wilderness, and
leaving on foot for several months.
Upon his return, the battery would be dead, and a few ( 50?) miles
from any passing help.
What he used was an old propane tank, and AIR (80's style smog) pump,
and some lines.

He'd fill the old propane tank with water, throw it on the fire, and
the line ran to the old AIR pump, which was rigged to run backwards
and act as a "turbine" spinning the alternaor and charging the battery
to allow his escape in the fall.

That was his story. It was Just crazy enough to work.. Maybe.

On Tue, 5 May 2009 19:38:34 -0700 (PDT), Half-Nutz
wrote:

On May 4, 3:46*pm, jeff_wisnia wrote:
I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing about
this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

Thanks guys,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

A former poster on this group....
Told a tale of parking his car Many miles into the wilderness, and
leaving on foot for several months.
Upon his return, the battery would be dead, and a few ( 50?) miles
from any passing help.
What he used was an old propane tank, and AIR (80's style smog) pump,
and some lines.

He'd fill the old propane tank with water, throw it on the fire, and
the line ran to the old AIR pump, which was rigged to run backwards
and act as a "turbine" spinning the alternator and charging the battery
to allow his escape in the fall.

That was his story. It was Just crazy enough to work.. Maybe.

Agreed - Just crazy enough that it might work.

But the efficiency would be abysmnal, AFAICT those were carbon-vane
pumps and weren't very efficient going forward, reverse would probably
be worse.

Now an air drill motor, that has far better possibilities...

And as has been brought up, there has to be enough power left in the
battery to excite the field windings on the rotor. Or the alternator
won't start alternating - chancing enough residualk magnetism after
several months of sitting is asking a lot.

If he thought far enough head to disconnect the battery when he left
the car, and the battery was in good shape, it's possible.

If he left in a hurry, he's screwed - "several months" and the
battery will be dead just from the clock and memory drains. Even 5 to
10 milliamps will kill a battery if you let the car sit over two
months - one month is about the limit without a trickle charger or
disconnecting the battery.

-- Bruce --

On Wed, 06 May 2009 00:30:06 -0700, Bruce L. Bergman
wrote:

On Tue, 5 May 2009 19:38:34 -0700 (PDT), Half-Nutz
wrote:

On May 4, 3:46Â*pm, jeff_wisnia wrote:
I'm thinking that all else left alone, it probably doesn't matter which
way the shaft of an automobile alternator is rotated since the machine
produces ac which is then rectified to create a polarized dc output.

Am I right about that?

The question came up just now when eldest son and I were kibitzing about
this week's "Car Talk" puzzler:

http://www.cartalk.com/content/puzzl...918/index.html

Thanks guys,

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

A former poster on this group....
Told a tale of parking his car Many miles into the wilderness, and
leaving on foot for several months.
Upon his return, the battery would be dead, and a few ( 50?) miles
from any passing help.
What he used was an old propane tank, and AIR (80's style smog) pump,
and some lines.

He'd fill the old propane tank with water, throw it on the fire, and
the line ran to the old AIR pump, which was rigged to run backwards
and act as a "turbine" spinning the alternator and charging the battery
to allow his escape in the fall.

That was his story. It was Just crazy enough to work.. Maybe.

Agreed - Just crazy enough that it might work.

But the efficiency would be abysmnal, AFAICT those were carbon-vane
pumps and weren't very efficient going forward, reverse would probably
be worse.

Now an air drill motor, that has far better possibilities...

And as has been brought up, there has to be enough power left in the
battery to excite the field windings on the rotor. Or the alternator
won't start alternating - chancing enough residualk magnetism after
several months of sitting is asking a lot.

If he thought far enough head to disconnect the battery when he left
the car, and the battery was in good shape, it's possible.

If he left in a hurry, he's screwed - "several months" and the
battery will be dead just from the clock and memory drains. Even 5 to
10 milliamps will kill a battery if you let the car sit over two
months - one month is about the limit without a trickle charger or
disconnecting the battery.

-- Bruce --
Funny, I've left vehicles sit all winter and they start in the
spring. Left them sit all summer and started them in the fall too.
No trickle charger connected.

On Thu, 07 May 2009 14:29:00 -0400, wrote:
On Wed, 06 May 2009 00:30:06 -0700, Bruce L. Bergman
wrote:

And as has been brought up, there has to be enough power left in the
battery to excite the field windings on the rotor. Or the alternator
won't start alternating - chancing enough residualk magnetism after
several months of sitting is asking a lot.

If he thought far enough head to disconnect the battery when he left
the car, and the battery was in good shape, it's possible.

If he left in a hurry, he's screwed - "several months" and the
battery will be dead just from the clock and memory drains. Even 5 to
10 milliamps will kill a battery if you let the car sit over two
months - one month is about the limit without a trickle charger or
disconnecting the battery.

Funny, I've left vehicles sit all winter and they start in the
spring. Left them sit all summer and started them in the fall too.
No trickle charger connected.

What make year and model were the vehicles in question?

I could do that with my 1961 Corvair or my 1945 Signal Corps
generator - no clock, no computer, no alarm, no battery drain. A new
battery could go six months easy, 1 year with your fingers crossed.

But try that with any car from about 1975 on, and the clock alone is
drawing 2 or 3 milliamperes (ma) to run. Add in the memory circuits
from the ECU, the radio station memory, and the alarm system, and now
you have a 10ma to 15ma draw that will kill the battery over time.

-- Bruce --

On Fri, 08 May 2009 01:34:11 -0700, Bruce L. Bergman
wrote:

On Thu, 07 May 2009 14:29:00 -0400, wrote:
On Wed, 06 May 2009 00:30:06 -0700, Bruce L. Bergman
wrote:

And as has been brought up, there has to be enough power left in the
battery to excite the field windings on the rotor. Or the alternator
won't start alternating - chancing enough residualk magnetism after
several months of sitting is asking a lot.

If he thought far enough head to disconnect the battery when he left
the car, and the battery was in good shape, it's possible.

If he left in a hurry, he's screwed - "several months" and the
battery will be dead just from the clock and memory drains. Even 5 to
10 milliamps will kill a battery if you let the car sit over two
months - one month is about the limit without a trickle charger or
disconnecting the battery.

Funny, I've left vehicles sit all winter and they start in the
spring. Left them sit all summer and started them in the fall too.
No trickle charger connected.

What make year and model were the vehicles in question?

I could do that with my 1961 Corvair or my 1945 Signal Corps
generator - no clock, no computer, no alarm, no battery drain. A new
battery could go six months easy, 1 year with your fingers crossed.

But try that with any car from about 1975 on, and the clock alone is
drawing 2 or 3 milliamperes (ma) to run. Add in the memory circuits
from the ECU, the radio station memory, and the alarm system, and now
you have a 10ma to 15ma draw that will kill the battery over time.

-- Bruce --
Before I bought my landlady's 85 Skylark, I used to warm it up about
every second month (it was driven 3000 kilometers in eight years) no
clock, mechanical pushbutton AM radio. I did have to put in a new
battery in '96, along with new tires.
Gerry :-)}
London, Canada