---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sun 08/31/14: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:13 PM - Re: Microphone Question (Robert L. Nuckolls, III) 2. 02:05 PM - Battery Cable Fitting (N38CW) 3. 02:16 PM - Re: Battery Cable Fitting (Robert L. Nuckolls, III) 4. 04:41 PM - Re: RV10-List: Shunt - Location (Justin Jones) 5. 05:50 PM - Re: Re: RV10-List: Shunt - Location (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 12:13:00 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Microphone Question At 08:12 PM 8/29/2014, you wrote: >Hello Bob, > >Haven't heard from you in a while, so I thought I'd check in. Have >you had an opportunity to look at the mic? > >Kevin I'm about ready to order an etched circuit board Emacs! with a schematic patterned after D.L. Josephson's suggestion earlier this year. Emacs! Should have boards by end of next week. The finished amplifier will be 0.48" wide by 0.83" long Bob . . . ________________________________ Message 2 _____________________________________ Time: 02:05:24 PM PST US Subject: AeroElectric-List: Battery Cable Fitting From: "N38CW" I am building an RV-8 with the battery installed in the forward baggage compartment. The battery contactor is mounted about 4" from the positive terminal. The simplest and shortest route for the cable would be a straight 4" length between the two. Is this acceptable, or should I take a somewhat indirect route to the contactor so that the cable has a bit of a loop in it? -------- Bill Settle RV-8 Fuselage Read this topic online here: http://forums.matronics.com/viewtopic.php?p=429707#429707 ________________________________ Message 3 _____________________________________ Time: 02:16:05 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Battery Cable Fitting At 04:03 PM 8/31/2014, you wrote: > >I am building an RV-8 with the battery installed in the forward >baggage compartment. The battery contactor is mounted about 4" from >the positive terminal. The simplest and shortest route for the >cable would be a straight 4" length between the two. Is this >acceptable, or should I take a somewhat indirect route to the >contactor so that the cable has a bit of a loop in it? Use a ~8" length of 4AWG welding cable with sufficient wire dress to avoid putting any stress on terminals on either end of the jumper wire. Use heavy-wall heat-shrink to provide vibration support at the terminals but let the stuff in the middle wave in the breeze. http://tinyurl.com/kfqjphg The above article illustrates M22759 'fat wire' but if it were my airplane, welding cable is the material of first choice. Bob . . . ________________________________ Message 4 _____________________________________ Time: 04:41:28 PM PST US From: Justin Jones Subject: AeroElectric-List: Re: RV10-List: Shunt - Location This is a perfect discussion for the aeroelectric list I'm sure Bob has some insight. I have CC'd the aeroelectric list email address Justin On Aug 30, 2014, at 6:47, Phillip Perry wrote: > Last night I was thinking about shunt locations and it seems like there ar e 3 different electrical locations for it. > > 1) Connected in the B-Lead (to measure the output of the ALT). > > 2) Connected to the battery (to measure the load on the battery; but it mi sses the contributions of electrons coming from the ALT to the main buss.) > > Location 3 seems to be the most logical spot for me. > > 3) Immediately before the main buss. So the ALT and Battery can be sendin g electrons to the buss and I'll be measuring them before they enter the bus s as they're consumed. Then I'm getting a measurement of true load (minus t he start). > > > Where have most of you installed yours? I really like option 3 but want t o make sure I'm not missing something. I'm also curious to know where yours is installed? I'm thinking of putting it on the aft side of the sub panel, s o I can yank a G3X screen and access it. > > Thanks, > Phil > > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 5 _____________________________________ Time: 05:50:00 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: RV10-List: Shunt - Location On Aug 30, 2014, at 6:47, Phillip Perry wrote: Last night I was thinking about shunt locations and it seems like there are 3 different electrical locations for it. 1) Connected in the B-Lead (to measure the output of the ALT). If you're going to measure current anywhere, this is the FIRST choice . . . I will elaborate later . . . 2) Connected to the battery (to measure the load on the battery; but it misses the contributions of electrons coming from the ALT to the main buss.) This is how it was done on cars and some airplanes for decades. Useful ONLY to the individual who KNOWS about how a battery behaves with a lot of electro-whizzies wrapped around it. Good diagnostic tool but it requires attention, memory (monitoring of trends) and an understanding of battery physics. I don't recommend it. 3) Immediately before the main buss. So the ALT and Battery can be sending electrons to the buss and I'll be measuring them before they enter the buss as they're consumed. Then I'm getting a measurement of true load (minus the start). But you KNOW what that number is . . . right? This is the FIRST task for crafting an electrical system is to list everything that needs power, separate to appropriate bus, tabulate the total bus energy needed under various flight configurations. It's called a Load Analysis and EVERY TC aircraft is blessed with one. You won't find an ammeter in series with any bus structure on a biz jet . . . ammeters monitor generator loads. The PRIMARY electrical system monitor is active notification of LOW VOLTS. When the light comes on, you look to see if the alternator is putting out ANYTHING . . . MAYBE it has popped a diode and is still putting out some energy but at a reduced rate. You have the option of reducing load until the light goes out. Are we talking actual SHUNTS or Hall-Effect Current Sensors. If the latter, one sensor can be used to monitor the output of both alternators in a dual system like Z-12 or Z-13/8 http://tinyurl.com/kgg8nva http://tinyurl.com/ag46m2f Check out any of the architecture figures at http://tinyurl.com/5wxzn7 You will not find an ammeter shunt anywhere except on the alternator B-leads . . . Your NUMBER ONE tool for dealing with electrical system malfunction is active notification of low voltage. Your response to that event should be . . . at most . . . the repositioning of a couple of switches whereupon you assume Plan-B for getting comfortably on the ground. If your Plan-B calls for reading displays, flipping switches, pushing/pulling breakers, fiddling with fuses and/or WONDERING how long the battery is going to last . . . then you blew it before your airplane's first flight. For the most part, an ammeter is useful for figuring things out AFTER you get back on the ground. Not having one available in flight should NOT be a matter of concern. Bob . . . ------------------------------------------------------------------------------------- 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.