Of drills, woods, bears, and PIV...

[1] Click and Clack are MIT graduates...

"CAMBRIDGE, Mass., April 1, 1999 -- Tom and Ray Magliozzi, hosts of the National Public Radio series Car Talk, will be the featured speakers at MIT's Commencement Exercises on June 4.

Known to millions of Americans as "Click and Clack, the Tappet brothers," both Magliozzis are MIT graduates: Thomas L. Magliozzi graduated in 1958 with a degree in Economics, while Raymond F. Magliozzi is a member of the class of 1972 with a Humanities degree."

;-)

[2] Alternator diodes are _usually_ 400PIV.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 Stormy on the East Coast today... due to Bush\'s failed policies.

Indeed; but I trust them anyhow....now that they have a proper flag...

Thanks. I was curious; as in the automotive work they have volumes large enough, and costing tight enough, to design & build special diodes Just For Them.

The thread diverged into power mosfets replacing them. Feel free to chase the References:

--
A host is a host from coast to coast.................wb8foz@nrk.com
& 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

Does the dead battery come with a car? If not, leave the above three items behind as you run away; they're just ballast.

Otherwise, just push-start the car.

[This could be a problem if it has automatic transmission, but unless you're either lacking a (functioning) left leg or are just too stupid to use manual transmission, why would it? Worse fuel economy, lower performance, lower reliability, increased cost; what's the point?]

Much harder to talk on a cell phone, put on makeup, or eat your Big Mac with a manual transmission. :-)

I've read that fuel economy is pretty much a wash these days -- many people don't have enough experience/skill with manuals that they actually end up with worse performance than an automatic.

Clearly manuals are the way to go if you want performance or really enjoy the driving experience itself. For the basic need of getting people from point A to point B comfortably with as little hassle as possible, it should be no surprise that automatics are preferred.

Why not just use the drill as a current limiter, in series with alternator pos terminal, generator, and the alternator positive wire. Cut one lead on the drill (either one) and the alternator pos lead with a sharp rock, strip with your teeth, twist the cut drill wires to the two halves of the alternator lead wires, plug the drill into the generator and turn the drill on. A variant of the old light bulb as a battery charging current limiter trick.

Or if it's a dirt road in the forest, uphill....

--
A host is a host from coast to coast.................wb8foz@nrk.com
& 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

I was, for _many_ years, a "schtick" person, like BC to 1987, but clutches, in traffic, get to be exhausting :-(

There's supposed to be a new "Z" (and a new "Q") in 2010, though who knows with the current economy... I'll buy automatic ;-)

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 Stormy on the East Coast today... due to Bush\'s failed policies.

Esp if you spend a lot of time in traffic jams.

--
Dirk

http://www.transcendence.me.uk/ - Transcendence UK
http://www.theconsensus.org/ - A UK political party
http://www.onetribe.me.uk/wordpress/?cat=5 - Our podcasts on weird stuff

A rolling start works fine in reverse.

Only in America (although automatic transmission seems to be gaining in popularity in East Asia).

In the UK (and most of Europe), automatic transmission is still quite rare.

Often a better gear ratio.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 Stormy on the East Coast today... due to Bush\'s failed policies.

Automatics make a lot of sense in hilly landscapes. Hills are hell on clutches.

John

who drives a manual Rabbit in San Francisco

o

But of course your foresight led you to avoid parking in a hollow.

th

e o

Spinning the alt with the drill might not very effective, just way too slow so I agree, use the drill as a current limiter. I couldn't follow your description of the connections exactly; but I'm sure one would have to open the alternator to get at the rectifiers. Connect the current-limited ac to two of the three rectifier terminals that normally get connected to the stator (after disconnecting the stator). I've hacked alternators before and there's just one thing I remember getting caught by -- threre's actually two sets of rectifiers in the alternators I'm familiar with (Delco). There's an extra set of much less robust rectifiers for tickling the field, and it's easy to burn them up if you do something wrong.

Taller, but worse. 2nd is better than 1st. It's a simple impedance matching problem.

the

A

automatics transmissions have clutches, dunno how long they last.

hills needn't be bad on the clutch in a manual transmission if you match match the engine speed before engaging the clutch.

the

A

Fluid coupling at low RPM's.

Spoken like one who's never had to hold at a San Francisco up-hill traffic light.

I vaguely remember (from my teens) a vehicle where, when the clutch pedal was pushed all the way to the floor, it engaged a brake... I think the feature was called "hill holder".

Of course you have to be careful... I also had a car where the starter button was under the clutch pedal.

Best stick vehicles have a hand brake lever between the seats.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 Stormy on the East Coast today... due to Bush\'s failed policies.

the

point A

And I forgot, since you hardly ever need the feature in AZ, _most_ automatic trannies won't allow roll-back while in Drive. My present vehicle will automatically up the RPM's to hold on a hill.

...Jim Thompson

--
| James E.Thompson, P.E.                           |    mens     |
| Analog Innovations, Inc.                         |     et      |
| Analog/Mixed-Signal ASIC\'s and Discrete Systems  |    manus    |
| Phoenix, Arizona  85048    Skype: Contacts Only  |             |
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  |
| E-mail Icon at http://www.analog-innovations.com |    1962     |
             
 Stormy on the East Coast today... due to Bush\'s failed policies.

No need to open the alternator. When it is not running it is essentially a diode between the output terminal and ground, actually 3 sets of two series diodes. The stator windings connect to the middle of these diodes, and will draw no current when the alternator is being used as a battery charger diode. Likewise the field diodes connect to the stator windings (I think) and would see essentially no voltage.

Having looked at the puzzler now I see tools, the drill, an extension cord and jumper cables are available, so no wire cutting is required. Just lift the output wire from the alternator, plug the extension cord into the generator, plug one side of the drill plug into the hot side of the extension cord socket, one jumper cable from the exposed other drill plug blade to the alternator output stud (your rectifier to frame ground) and the other jumper cable from the generator frame ground (conected to neutral) to the alternator output lead or the battery plus terminal (where the alternator output wire connects). The jumper cable connections to the car can be reversed.

The drill is a universal motor (DC motor with a bridge rectifier), which will run on either polarity DC also, or at reduced power on half wave rectified AC, rectified by the alternator diodes. Leave it running until the battery is charged enough to start (battery could be overcharged with this setup).

If my description is still not clear, try sketching the whole thing including the drill bridge rectifier and the alternator bridge rectifier. Drill current limits and alternator rectifies.