X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from tomcat.al.noaa.gov ([140.172.240.2] verified) by logan.com (CommuniGate Pro SMTP 4.3.4) with ESMTP id 1009027 for flyrotary@lancaironline.net; Tue, 21 Jun 2005 12:43:26 -0400 Received-SPF: none receiver=logan.com; client-ip=140.172.240.2; envelope-from=bdube@al.noaa.gov Received: from mungo.al.noaa.gov (mungo.al.noaa.gov [140.172.241.126]) by tomcat.al.noaa.gov (8.12.11/8.12.0) with ESMTP id j5LGgfMG027548 for ; Tue, 21 Jun 2005 10:42:41 -0600 (MDT) Message-Id: <6.2.1.2.0.20050621100924.03cf0c10@mailsrvr.al.noaa.gov> X-Mailer: QUALCOMM Windows Eudora Version 6.2.1.2 Date: Tue, 21 Jun 2005 10:41:34 -0600 To: "Rotary motors in aircraft" From: Bill Dube Subject: Dc-DC regulator (was: Racemate Alternator) In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed > > It is also within the realm of possibilities that you could >replace the regulator with a much more elaborate DC to DC converter type. >This could "buck convert" the high voltage (at high RPM) to low voltage >with greater amperage. > > Bill Dube' > > Are the parts for this circuitry available reasonably? Yes. Not terribly cheap, however. Probably a couple hundred for a 500 Watt regulator. Price would roughly scale with wattage. Keep in mind these costs are for one-off, not large scale production. In larger scale production, 500 watts would cost $80 or so. >Are they dead bang reliable? Can be. Vicor makes mil-spec parts, for a price. > Both items are vital if several of us start using them. Also while we > shunted into talking about the Harley alternator in the thread, I believe > the racemate alternator is designed to a higher rpm use. You need not get too concerned about the RPM. Only the magnets spin. >IE doesn't produce full voltage and amprage until higher RPM normally. The minimum RPM is not much of an issue for this application. I'm not sure what sort of regulator comes stock with these units. I suspect that they are using some sort of simplistic PWM voltage regulator, but they could be using a buck conversion switcher (DC-DC converter.) The development cost of the switcher would be significantly higher, but production costs would not much different. I am "officially" a mechanical engineer too, by the way. Bill Dube'