X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Sat, 07 Jul 2007 20:36:04 -0400 Message-ID: X-Original-Return-Path: Received: from global.delionsden.com ([66.150.29.112] verified) by logan.com (CommuniGate Pro SMTP 5.1.10) with ESMTPS id 2163112 for lml@lancaironline.net; Sat, 07 Jul 2007 02:52:21 -0400 Received-SPF: none receiver=logan.com; client-ip=66.150.29.112; envelope-from=n103md@yahoo.com Received: from bmackey by global.delionsden.com with local (Exim 4.62) (envelope-from ) id 1I748q-00023C-0M for lml@lancaironline.net; Sat, 07 Jul 2007 02:51:40 -0400 Received: from 69.12.132.145 ([69.12.132.145]) (SquirrelMail authenticated user bmackey) by www.bmackey.com with HTTP; Fri, 6 Jul 2007 23:51:40 -0700 (PDT) X-Original-Message-ID: <6294.69.12.132.145.1183791100.squirrel@www.bmackey.com> X-Original-Date: Fri, 6 Jul 2007 23:51:40 -0700 (PDT) Subject: Flap Switch From: "bob mackey" X-Original-To: lml@lancaironline.net User-Agent: SquirrelMail/1.4.8 MIME-Version: 1.0 Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) Importance: Normal X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - global.delionsden.com X-AntiAbuse: Original Domain - lancaironline.net X-AntiAbuse: Originator/Caller UID/GID - [32015 2012] / [47 12] X-AntiAbuse: Sender Address Domain - yahoo.com X-Source: X-Source-Args: X-Source-Dir: Yesterday I posted a design for a simple solid-state flap motor controller. I didn't know it at the time, but there are many motor controllers available in an integrated form. This general type of reversible motor circuit is called an "H-bridge". Which just goes to show that it is easier to find stuff on the Internet if you know what it is called. A better explanation is here: http://www.ikalogic.com/H_bridge_1.php And circuits designed to do exactly this job are here: http://www.national.com/pf/LM/LMD18200.html http://www.national.com/an/AN/AN-694.pdf http://www.cadvision.com/blanchas/hexfet/np-s.htm And this does much more than we need, but could be controlled by your flight computer or autopilot or whatever.... http://www.robotshop.ca/home/suppliers/dimension-engineering-en/dimension-engineering-syren-10.html http://www.robotshop.ca/PDF/SyRen10-20.pdf With any of those, the switch wiring is extremely simple. An SPDT is connected with center pole to fused +12V. The other two leads are connected via the limit switches to the P1 and P2 (ikalogic) or A and B (Cadvision) pins. With the National chip, the wiring would be slightly different. I'll leave the details to someone who really wants to build it into the airframe.