---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 11/20/09: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 0. 12:19 AM - Just A Few Days Left; Still Trailing Last Year... (Matt Dralle) 1. 05:25 AM - Re: Crowbar Circuit (Robert L. Nuckolls, III) 2. 03:15 PM - Dan's Switches (messydeer) 3. 03:20 PM - Re: Dan's Switches (messydeer) 4. 03:28 PM - Re: Dan's Switches (messydeer) 5. 03:33 PM - Re: Dan's Switches (messydeer) 6. 03:49 PM - Re: Dan's Switches (messydeer) ________________________________ Message 0 _____________________________________ Time: 12:19:17 AM PST US From: Matt Dralle Subject: AeroElectric-List: Just A Few Days Left; Still Trailing Last Year... Dear Listers, There are just a few more days left of this year's List Fund Raiser! Response has been very good, but still well behind last year. If you've been waiting until the last minute to make your contribution and maybe even pick up a great gift, now might be good time to show your support! Please remember that there isn't any sort of commercial advertising on the Lists and the *only* means of keeping these Lists running is through your Contributions during this Fund Raiser. Please make a Contribution today! http://www.matronics.com/contribution Thank you! Matt Dralle Matronics Email List Administrator ________________________________ Message 1 _____________________________________ Time: 05:25:00 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Crowbar Circuit At 12:35 PM 11/19/2009, you wrote: > >If anyone is interested I've posted a circuit and veroboard layout >for a tested and working crowbar circuit based on the MC3423 chip on >the blog for my Wittman Tailwind build. Total parts cost around $5. > >http://tailwindbuild.blogspot.com/2009/11/15th-november-2009-overvoltage-crowbar.html > >Click on the pics/diagrams to enlarge > >The variable resistor allows the crowbar voltage to be set as >required and compensates for differences in the internal reference >voltage on the MC3423. Some thoughts based on lessons-learned: You need to select the trip time delay capacitor for something on the order of 50-100 milliseconds. Further, depending on how "twitchy" the SCR is, you may experience nuisance triggers of the SCR due to very low energy but fast rise-time noises on the bus. These are effectively dealt with by tying a 10 ohm resistor from SCR gate to ground (which may mean a commensurate increase in gate drive requirements from the MC3423). Bob . . . --------------------------------------- ( It's MATRONICS FUND RAISER MONTH! ) ( Do your part to keep this marvelous ) ( tool sharp and available to all our ) ( brothers in the OBAM aviation ) ( community. ) --------------------------------------- ________________________________ Message 2 _____________________________________ Time: 03:15:01 PM PST US Subject: AeroElectric-List: Dan's Switches From: "messydeer" Hello! I've done a fair amount of crimping and a little soldering while wiring my instrument panel mockup, and have a few questions. Maybe posting one or two pics per post will work. This is for my Jabiru 3300 Sonex with a standard ~30 degree tilted panel. I've put a piano hinge along the bottom and top with a few nutplates to go on the side. The tank and glareshield are removed. Tank has roughly the same cross section as the panel face, starts about a foot in front of the panel to the firewall. -------- Dan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=274009#274009 Attachments: http://forums.matronics.com//files/panel_front_112.jpg ________________________________ Message 3 _____________________________________ Time: 03:20:37 PM PST US Subject: AeroElectric-List: Re: Dan's Switches From: "messydeer" This pic is from the left side looking right, with the panel tilted forward. Some have had interference problems with the top of the Enigma hitting the glare shield, but mine just fits. At the top of the pic you can see the cover for the main buss. It's mocked up to fit on the underside of the glare shield. Taking out the top hinge pin will let it swing down for easier access. On the bottom side of the cover I've mounted a section of ground tabs. -------- Dan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=274011#274011 Attachments: http://forums.matronics.com//files/panel_pivoted_119.jpg ________________________________ Message 4 _____________________________________ Time: 03:28:55 PM PST US Subject: AeroElectric-List: Re: Dan's Switches From: "messydeer" This is with the panel in the closed position. The channel that the lower piano hinge attaches to is 025 with either 1/2" or 3/4" flanges. Some of the longer wires, like the blue one in the foreground, can be tucked away from the flange. There are a few shorter wires that need to have a zip tie pull them up and away, or maybe ben up the switch terminals. The 3rd switch back is a good example. It has a white and red wire resting on the flange. In the foreground is my security switch for the starter button, mentioned in earlier posts. -------- Dan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=274017#274017 Attachments: http://forums.matronics.com//files/switch_gang_200.jpg ________________________________ Message 5 _____________________________________ Time: 03:33:40 PM PST US Subject: AeroElectric-List: Re: Dan's Switches From: "messydeer" Since a DPDT switch is the same size and almost the same price as a SPST, I thought I could increase switch reliability by putting in 2-3 instead of 1-3 switches. The pic shows one for a magneto lead. I separated the shield and put blue heatshrink on the braid and covered the junction with a piece of clear heatshrink. -------- Dan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=274018#274018 Attachments: http://forums.matronics.com//files/shielded_mag_wire_to_2_3_switch_191.jpg ________________________________ Message 6 _____________________________________ Time: 03:49:29 PM PST US Subject: AeroElectric-List: Re: Dan's Switches From: "messydeer" Last week I crimped connections betwen my regulator and alternator relay. The Jabiru regulator comes with a harness or whatever you call the plastic thing with 6 male faston blades inside. Besides being a bit cramped in there, one of the blades is a bit loose. I think it just got pushed or pulled out of its socket, since I can't budge the female-male faston connection. For this reason I'm thinking of cutting off the plastic harness (and tabs, if needed) to free up the individual wires. I also realize the fastons to the relay aren't in all the way. And it needs a diode. -------- Dan Read this topic online here: http://forums.matronics.com/viewtopic.php?p=274020#274020 Attachments: http://forums.matronics.com//files/regulator_fastons_118.jpg ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.