Date: Thursday, March 19, 2009, 9:08 AM Since it's quiet: =A0 When I was a kid a guy at the parts store demonstrated to my Dad that when = electrical power was needed, a generator put a load on the engine. After th= at, my Dad was careful not to run lights, radio, heater fan, or other non-e= ssentials when he was trying to get good gas mileage. =A0 I have continued that tradition, however, I have seen it stated that electr= ical draw on an alternator doesn't increase the mechanical load. =A0 When low on fuel will it help to turn off electrical components not needed = for flight? =A0 Is it true of an alternator; an electrical power demand doesn't cause an in= creased mechanical load? =A0 Or, does keeping headlights on during the day decrease gas mileage? =A0 Thanks! Ben --0-724629452-1237470309=:74011 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable

It doesn't matter what is generating the= electricity, a generator, alternator or battery it takes at least 1 HP to = make 746 watts of electricity.

That is the conversion factor under ideal conditions with an efficienc= y of 1.

Of course in the real world there are losses that reduce the amount of= electricity or increase the horsepower necessary.

Alternators are probably more efficient than generators but then there= are losses in the rectifier and regulator circuits.

The laws of physics dictate that there is no free lunch.

Energy can neither be created or destroyed, only converted from one fo= rm to another

(mechanical,electrical,chemical etc.), and always with losses in the c= onversion process.

So turning off electrical devices will reduce the load on the engine b= y whatever amount they draw plus what ever losses are required in the conve= rsion.

Jim

--- On Thu, 3/19/09, Ben Baltrusaitis &l= t;expressben@verizon.net> wrote:

From: Ben Baltrusaitis <expressben@verizon.net>=
Subject: [FlyRotary] Alternator (Off topic)
To: "Rotary motors in ai= rcraft" <flyrotary@lancaironline.net>
Date: Thursday, March 19, 20= 09, 9:08 AM

Since it's quiet= :

When I was a kid= a guy at the parts store demonstrated to my Dad that when electrical power= was needed, a generator put a load on the engine. After that, my Dad was c= areful not to run lights, radio, heater fan, or other non-essentials when h= e was trying to get good gas mileage.

I have continued= that tradition, however, I have seen it stated that electrical draw on an = alternator doesn't increase the mechanical load.

When low on fuel= will it help to turn off electrical components not needed for flight?

Is it true of an= alternator; an electrical power demand doesn't cause an increased mechanic= al load?

Or, does keeping= headlights on during the day decrease gas mileage?

Thanks!
Ben
=

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