[ExI] puzzler

spike spike66 at att.net
Sun May 10 05:08:54 UTC 2009

Excellent!  David after I saw your post I realized this might work, so there
are two different ways to sleep that night in a warm bed instead of a cold
truck.  Your idea is one: remove the alternator belt and rig the drill to
spin the alternator.  Here's what I thought:
Recall that hand drills are variable speed devices, using a potentiometer in
the trigger.  In my misspent youth, I found an old drill in the trash,
plugged it in, didn't work, took it apart and noticed that it was a DC
motor.  It had a rectifier circuit going to the potentiometer in the trigger
and that output going to brushes in the motor.  So I reasoned I should be
able to run the drill motor off of a car batter by taking out the rectifier
and putting in 12 volts just upstream of the trigger potentiometer.  Works
great.  So store this away: if you are away out in the hootnannies with no
electric power but have the usual tools one carries in a take-along tool
bag, and you need to drill a hole in something, remember you can splice in
ahead of the trigger and run your hand drill off your car battery.
So I reasoned that if a drill can run off of a battery, then a battery can
run off of a drill.  So I would remove the drill motor brushes, attach the
jumper cables to the car battery, take about a 10 amp fuse from something
non-critical, put it in series, then gradually pull the trigger until the
fuse burns out, lock the trigger in place right there, then connect it back
without the fuse and let the rectifier circuit in the drill charge the
battery.  With ten amps, the truck should start within an hour or two.


From: extropy-chat-bounces at lists.extropy.org
[mailto:extropy-chat-bounces at lists.extropy.org] On Behalf Of David C. Harris
Sent: Saturday, May 09, 2009 6:06 PM
To: ExI chat list
Subject: Re: [ExI] puzzler

You know how to challenge us!  

OK, some generators have a 12 volt DC output that could be carried to the
battery directly.  I have such a generator in my back yard storage, thanks
to Enron's fraud that made me think that shortages of 110 juice would be a
frequent occurrence in California.

But assuming this generator was not so equipped, I'd take the generator's
110 AC thru the extension cord to the electric drill with a big drill and
some little ones jammed into the square drive side of a socket so the
drill's rotation would drive the nut that holds the pulley that is bolted to
the CAR's generator or alternator.  Loosen the generator or alternator drive
belt so  you're just turning the pulley that makes 12V for the car battery.
Disconnect the battery positive, temporarily, from devices that might
deplete the stream of entering 12V power.

There is some remote chance that the carboxylic acid(s) in the olive oil
would orient (because carboxylic acids have a positive end and a hydrophobic
oily chain) in contact with the battery acid and act as some sort of diode,
allowing more electrons to move in one direction than the other direction of
the 110 alternating current.  Different numbers of electrons makes a DC
current in one direction.  I'd do the drill method before Googling on the
electrical properties of olive oil and acids.

How'd I do?

  - David Harris, Palo Alto

spike wrote: 

....  I suspect even the monster brains on this forum will not get it.  Here
it is:
"... brought along my generator, radio, etc. I also packed an extension
cord, my electric drill and the bits, and my socket and wrench set. ...
jumper cables, a roll of duct tape and a quart of Fillipo Berio Extra Virgin
Olive Oil....

"If only there was a way to get power from the generator which is making 110
volts AC and get that into my dead battery, which is 12 volts DC. The
question is: how can I do it with only the items at my disposal?"
I nailed it because of something I discovered during my misspent youth.  The
answer will be given on the Car Talk show tomorrow.  I will post the answer
later today.  Any guesses?

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