X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail03.syd.optusnet.com.au ([211.29.132.184] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTPS id 3554613 for flyrotary@lancaironline.net; Sat, 21 Mar 2009 05:08:03 -0400 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.184; envelope-from=lendich@optusnet.com.au Received: from ownerf1fc517b8 (d220-237-226-129.dsl.nsw.optusnet.com.au [220.237.226.129]) by mail03.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id n2L97IIa027563 for ; Sat, 21 Mar 2009 20:07:19 +1100 Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Alternator (Off topic) Date: Sat, 21 Mar 2009 19:07:18 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0020_01C9AA58.414BA410" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 0617-3, 04/28/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0020_01C9AA58.414BA410 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Jim, To my way of thinking, the alternator is running with the engine RPM = so the power generated is relative to the RPM. This can't be changed = unless you disconnect the alternator. The alternator charges the battery - which in turn runs the = accessories. So no savings can be made unless you disconnect the alternator. So turning off things does little - it only saves the battery charge = which is being recharged whether you like it or not. Unless you put a clutch on the alternator. So no savings of HP or fuel. In some cases, systems like to have a continuous drain on the battery, = like the Harleys. That's why they run around with their lights on - so = they don't overheat the battery. The chaps who select 'lights on' = rather than the hard wired factory systems, always have battery = problems.=20 George ( down under) 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 = efficiency 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 form to another=20 (mechanical,electrical,chemical etc.), and always with losses in = the conversion process. So turning off electrical devices will reduce the load on the = engine by whatever amount they draw plus what ever losses are required = in the conversion. Jim --- On Thu, 3/19/09, Ben Baltrusaitis = wrote: From: Ben Baltrusaitis Subject: [FlyRotary] Alternator (Off topic) To: "Rotary motors in aircraft" Date: Thursday, March 19, 2009, 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 careful not to run lights, radio, heater = fan, or other non-essentials when he 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 mechanical load? Or, does keeping headlights on during the day decrease gas = mileage? Thanks! Ben=20 ------=_NextPart_000_0020_01C9AA58.414BA410 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 
 Jim,
To my way of thinking, the alternator = is running=20 with the engine RPM so the power generated is relative to the RPM. = This can't=20 be changed unless you disconnect the alternator.
 
The alternator charges the battery - = which in=20 turn runs the accessories.
 
So no savings can be made unless you = disconnect=20 the alternator.
 
So turning off things does little - it = only=20 saves the battery charge which is being recharged whether you like it = or=20 not.
Unless you put a clutch on the = alternator.
 
So no savings of HP or fuel.
 
In some cases, systems like to have a = continuous=20 drain on the battery, like the Harleys. That's why they run around = with their=20 lights on - so they don't overheat the battery.  The chaps=20 who select 'lights on' rather than the hard wired factory = systems,=20 always have battery problems. 
George ( down under)
 
It doesn't matter what is generating the electricity, a = generator,=20 alternator or battery it takes at least 1 HP to make 746 watts = of=20 electricity.
That is the conversion factor under ideal conditions with = an=20 efficiency of 1.
Of course in the real world there are losses that reduce = the amount=20 of electricity or increase the horsepower necessary.
Alternators are probably more efficient than generators but = then=20 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=20 form to another
(mechanical,electrical,chemical etc.), and always with = losses in=20 the conversion process.
So turning off electrical devices will reduce the load on = the=20 engine by whatever amount they draw plus what ever losses are = required=20 in the conversion.
Jim

--- On Thu, 3/19/09, Ben = Baltrusaitis=20 <expressben@verizon.net> wrote:
From:=20 Ben Baltrusaitis <expressben@verizon.net>
Subject:=20 [FlyRotary] Alternator (Off topic)
To: "Rotary motors in = aircraft"=20 <flyrotary@lancaironline.net>
Date: Thursday, March = 19, 2009,=20 9:08 AM

Since it's=20 quiet:
 
When I was a kid=20 a guy at the parts store demonstrated to my Dad that when = electrical=20 power was needed, a generator put a load on the engine. After = that, my=20 Dad was careful not to run lights, radio, heater fan, or other = non-essentials when he was trying to get good gas=20 mileage.
 
I = have continued=20 that tradition, however, I have seen it stated that electrical = draw on=20 an alternator doesn't increase the mechanical = load.
 
When low on fuel=20 will it help to turn off electrical components not needed for=20 flight?
 
Is = it true of an=20 alternator; an electrical power demand doesn't cause an = increased=20 mechanical load?
 
Or, = does keeping=20 headlights on during the day decrease gas = mileage?
 
Thanks!
Ben
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