<sending in 2 parts>
False (again, the Law of Conservation of Energy: there are no freebies).
This is expressed in the concept of 'load.' The load on the alternator
increases or decreases depending on the electrical demands placed on it. At
cruise, the load on the alternator--this applies to generators, too--is more or
less stable. Turn on the lights, and the load, or power demand on the
alternator increases by the power needed by the lights. The alternator needs to
produce more power, measured in watts, to power the engine plus the lights (the
voltage regulator, which controls power to the rotor of an alternator--or to
the field coils of a generator--will supply the extra 'feed' current). This
additional power, measured (usually) in HP, comes from the engine. There are
conversion factors that convert HP to watts, to BTUs and any other measure of
energy and back. If you track it carefully, you will find that your mileage is
less at night with the lights on than during the day (not much, but measurable,
esp. in a low-powered auto).
<continued>
----- Original Message -----
From: "Bob Johnson" <bjsbj8@gmail.com>
To: "Oudesluys" <coudesluijs@chello.nl>
Cc: "Bob Spidell" <bspidell@comcast.net>, "healeys" <healeys@autox.team.net>
Sent: Thursday, February 5, 2009 8:24:29 AM GMT -08:00 US/Canada Pacific
Subject: Re: [Healeys] electrc fan vs. belt drive
There is an implication here, I believe, that the greater the power
requirement, the harder it is to spin the generator/ alternator. Isn't the
relationship between the engine and the gen/alt a fixed relationship between
the pulleys? And following that, the the regulator controls the amount of
electrical output as required to run whatever you are trying to run on your
vehicle? I don't know, but it just seems logical to me that the motor turns,
the gen/alt turns and the horsepower to do this work would be essentially
constant regardless of electrical power requirements. If you take the
mechanical water pump out of the system you would save hp requirement for the
engine, IOW the engine would spin more easily. Then the electrical water pump,
while requiring hp to run the pump motor would be "free" because more
electricity would be released by the regulating system. It was always being
produced, just not being used. Is this true or false?
Bob Johnson
BJ8
_______________________________________________
Support Team.Net http://www.team.net/donate.html
Healeys@autox.team.net
http://autox.team.net/mailman/listinfo/healeys
http://www.team.net/archive
|