---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 02/14/20: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:58 AM - Re: Charge Pump (Earl Schroeder) 2. 10:52 AM - Always hot power for fuel injectors and ignition coils (cofford) 3. 11:35 AM - Re: Always hot power for fuel injectors and ignition coils (Charlie England) 4. 12:56 PM - Re: Always hot power for fuel injectors and ignition coils (Robert L. Nuckolls, III) 5. 06:47 PM - Alternator, battery and bus question (Krea Ellis) ________________________________ Message 1 _____________________________________ Time: 07:58:26 AM PST US From: Earl Schroeder Subject: Re: AeroElectric-List: Charge Pump This might work for me: WRB1224YMD-6W. https://www.ebay.com/itm/3-pcs-5- 12-15-24-48V-6W-Isolated-Regulated-Dual-Single-Output-DC-DC-Converter/222767 551092?hash=item33ddfb1274:m:m7JLZJsEF2VDrfRwBcZHJsg I am supplying 24V to a dozen or so 4-20 mA instruments Four CH, EG, 2 fue l tank levels etc. This is for a back up in case the existing 12-24 unit fa ils. I have discovered that it is no longer available. Thanks for your help, Earl Schroeder P.S. I have four or so 12 V battery chargers that have failed over the years . Most are =98Shusmackers=99.. anyway that is what I call them. Let me know if you want to =98look=99 at them before they hit t he trash. (I live near Evansville, IN). 7ii3 on St Louis sec. > On Feb 13, 2020, at 10:18 AM, Robert L. Nuckolls, III wrote: > > =EF=BB At 08:22 AM 2/13/2020, you wrote: >> Is the input ground isolated from the output? > > Probably not. It's difficult to find > such devices with 'isolated' or 'floating' > outputs. They exist and generally in > low power (couple watts) versions. > > Examples: https://tinyurl.com/rplxlsk > > > Bob . . . ________________________________ Message 2 _____________________________________ Time: 10:52:23 AM PST US Subject: AeroElectric-List: Always hot power for fuel injectors and ignition coils From: "cofford" Hi everyone, I'm currently planning the electrical architecture for my RV-8 with EFII and I've been following the recent discussions of fuel injector power with great interest. Does anyone connect the positive side of the injectors and coils to the always-hot battery bus and leave them powered all the time, or are they generally always switched? I'm leaning towards a dual-feed bus with diode-protected feeds from the main contactor and a relay on an aux battery. I'll post a schematic when I get done drawing it. Thanks, Casey Read this topic online here: http://forums.matronics.com/viewtopic.php?p=494804#494804 ________________________________ Message 3 _____________________________________ Time: 11:35:52 AM PST US Subject: Re: AeroElectric-List: Always hot power for fuel injectors and ignition coils From: Charlie England On 2/14/2020 12:49 PM, cofford wrote: > > Hi everyone, > > I'm currently planning the electrical architecture for my RV-8 with EFII and I've been following the recent discussions of fuel injector power with great interest. Does anyone connect the positive side of the injectors and coils to the always-hot battery bus and leave them powered all the time, or are they generally always switched? > > I'm leaning towards a dual-feed bus with diode-protected feeds from the main contactor and a relay on an aux battery. I'll post a schematic when I get done drawing it. > > Thanks, > Casey > My opinion is that there's a difference between powering engine components directly from a (unfortunately named) 'battery bus' and leaving them always hot. My *engine bus* is fed from the battery, by a fusible link-protected feeder, *through a high current switch*. It also has a secondary (backup) switched feed from the main a/c bus. All the engine components are fed from this engine bus. This is *not* my always-hot battery bus. If you start feeding multiple components with always-hot feeds, it's likely to get very difficult to keep track of what's hot & what's not when working on the plane. It also makes it impossible to make everything 'cold' for an emergency landing. As has been discussed here recently, with proper installation, the only way (at least at the type of odds of a wing failure) an entire bus can go down is a failure of the switching mechanism, which is why there are two feeds to the bus. FWIW, Charlie ________________________________ Message 4 _____________________________________ Time: 12:56:50 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Always hot power for fuel injectors and ignition coils >I'm currently planning the electrical architecture for my RV-8 with >EFII and I've been following the recent discussions of fuel injector >power with great interest. Does anyone connect the positive side of >the injectors and coils to the always-hot battery bus and leave them >powered all the time, or are they generally always switched? What manufacture of EFII system and what are the recommendations of the manufacturer? >I'm leaning towards a dual-feed bus with diode-protected feeds from >the main contactor and a relay on an aux battery. I'll post a >schematic when I get done drawing it. What powers the rest of the airplane? What kind of engine. What architecture? Bob . . . ________________________________ Message 5 _____________________________________ Time: 06:47:27 PM PST US From: Krea Ellis Subject: AeroElectric-List: Alternator, battery and bus question What happens if an alternator is temporarily overloaded (lets say its rated at 40 amps) and you draw 45 amps. Assume the battery is well maintained and fully charged. A current limiter (ANL/AML) is installed as well. You intend to load shed, but dont do so immediately. What are the consequences? My assumption is the voltage will drop and the battery will supplement the alternator for some period of time until you can load shed and then the alternator will carry the entire load? I assume the current limiter will not blow with a short duration small overload. Thanks in advance for educating me. Krea Ellis ------------------------------------------------------------------------------------- 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.