---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 12/22/14: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:49 AM - Power stabilizer wiring (Weaver, Erich) 2. 07:28 AM - Re: How does the Ducatti rectifier/regulator work? (Robert L. Nuckolls, III) 3. 10:50 AM - SD8 output at 28V? (digidocs) 4. 01:15 PM - Re: Power stabilizer wiring (Robert L. Nuckolls, III) 5. 01:37 PM - Re: SD8 output at 28V? (Robert L. Nuckolls, III) 6. 01:53 PM - Re: SD8 output at 28V? (digidocs) 7. 04:59 PM - Power stabilizer wiring (Weaver, Erich) 8. 05:55 PM - N811HB analysis files (Bower, Bob) 9. 06:17 PM - Re: Power stabilizer wiring (Jeff Luckey) ________________________________ Message 1 _____________________________________ Time: 06:49:53 AM PST US From: "Weaver, Erich" Subject: AeroElectric-List: Power stabilizer wiring I should have stated previously that the manufacturer has indicated that failure of the IPS results in pass through of the bus voltage. Assuming that's true, operation of the EFIS should continue unless I was in a brownout situation. This e-mail and any attachments contain URS Corporation confidential information that may be proprietary or privileged. If you receive this message in error or are not the intended recipient, you should not retain, distribute, disclose or use any of this information and you should destroy the e-mail and any attachments or copies. ________________________________ Message 2 _____________________________________ Time: 07:28:02 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: How does the Ducatti rectifier/regulator work? Yes but not immediately. I did a one off many years ago for the positive side of a wound field alternator with a commercial IC that has worked out well. I'd like to regulate the charging on some small equipment that is hard on batteries and I also told myself that I'd roll my own if I ever need another John Deere unit for the airplane. I like more temperature compensation than commercial regulators incorporate (and my batteries seem to agree...) Ken Understand. If that project bubbles to the top of your to-do list, lets talk. If you like, I could perhaps contribute to your project with an etched circuit board layout. Keep an eye on developments in the rectifier/regulator world for PM alternators. The Ducati design is now probably pushing 40 years old and there's been a lot of new ideas and products added to the mix in the interim. I'm exploring some of the COTS options for a client and may have some recommendations to share in the not too distant future. Then there's those lithium thingys getting a toe hold in the marketplace. They're here to stay. They're not the ticking time- bomb we've been let to imagine. BUT . . . they are NOT lead-acid drop-ins. Every kid and his dog wanted to get into the SVLA business wayyyyy back when and those unable to perform were a brief flash on the horizon. I suspect the lithium products will bubble up and be filtered in the marketplace as well. I'm working the 4th installment to the lithium saga for Kitplanes. I love this business . . . tomorrow . . . you can do more for $less$ with better performance, lower weight, smaller space than you can today. It's exciting. But just because the Ducati style is dated does not mean that it's unserviceable or unworthy of consideration for improvements. It's your kitchen chef . . . variations on a theme may be just what's needed to fit your design goals. Bob . . . ________________________________ Message 3 _____________________________________ Time: 10:50:26 AM PST US Subject: AeroElectric-List: SD8 output at 28V? From: "digidocs" Hello Aeroelectric, Does anyone have information about the SD8 output performance at 28V? B&C are advertising a 28V version, but were unable to provide any data when I asked. I also took Bob's 12.5V/13.8V output ratings at 3100 alternator RPM and built a Thevenin equivalent circuit. That shows open circuit voltage of only ~20V. Hopefully that's not an accurate way to model this device. David Read this topic online here: http://forums.matronics.com/viewtopic.php?p=436011#436011 ________________________________ Message 4 _____________________________________ Time: 01:15:34 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Power stabilizer wiring At 18:33 2014-12-21, you wrote: Rather than a standby battery I am installing a 4 amp rated 'Intelligent Power Stabilizer' on my z-13/8 wired RV for brownout protection to one of my two EFIS screens during startup. The EFIS draws 1 amp. The manual says to install a 12 amp fuse on the power inlet to the IPS unit and a second 5 amp inline fuse on the wire providing power from the IPS to the secondary power inlet on the EFIS. First question: the 12 amp fuse can just be on my main bus so no hassle there but i would rather not have the 5 amp inline fuse buried behind the subpanel with the IPS if its not absolutely necessary. Do I definitely need both fuses for adequate protection? Fuses should be part of your system for one reason only . . . to protect wires and to prevent a failure on one feeder from propagating into other systems. Hence the common-bus/multiple-feeder architectures with individual protection on each feeder. If the manufacturer calls for a fuse in the output lead, then it's very much worth your time and effort to inquire as to the circumstances under which that fuse might operate. Not being familiar with the design of his product, we're in a poor position to conduct an FMEA. I hope that his reply would state that the output fuse is unnecessary. If the device is rated at 4A output (56 watts) and assuming at LEAST 80% efficiency then input demand would be on the order of 75 watts. Under brown out conditions (8 volts or so) the current TRANSIENT would be on the order of 10A . . .so the 12A protection call-out seems reasonable for a FULLY loaded system. Your system loads as installed will be approximately 1/4 rated max values so you have plenty of headroom in terms of wire protection. 12A call-out is a bit funky . . . go for 10A . . . a fuse you can actually buy. Second question: Any reason the IPS can't be used as the sole source of power to the EFIS rather than as backup? If I wired the IPS to the ebus I have the backup alternator I can use should the primary fail. Maybe the IPS is not intended for full time operation or perhaps it draws more current than practical for the ebus? Energy is energy is energy. These switchmode power supplies are constant power systems meaning that as bus voltage falls, INPUT current will rise to maintain a constant power at the output terminals. Your 1A EFIS demand (14W) means normal bus (14.5v) draw is about 1.3A, at end of life on battery only ops (11v) the draw rises to about 1.5A. During brown out transient of say 8v, the draw rises to 2.2A. So 10A circuit protection from the bus seems quite adequate. Bob . . . ________________________________ Message 5 _____________________________________ Time: 01:37:06 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: SD8 output at 28V? At 12:49 2014-12-22, you wrote: > >Hello Aeroelectric, > >Does anyone have information about the SD8 output performance at 28V? > >B&C are advertising a 28V version, but were unable to provide any >data when I asked. > >I also took Bob's 12.5V/13.8V output ratings at 3100 alternator RPM >and built a Thevenin equivalent circuit. That shows open circuit >voltage of only ~20V. Hopefully that's not an accurate way to model >this device. > >David Both 14 and 28v versions are wound by B&C. The 28v version would have more turns on it than the 14v. The alternator's output is roughly limited by the magnetics. This is a 100W alternator frame so I would imagine that the 28v performance for current is 1/2 that of the 14v version. I'll be at B&C in then next few weeks . . .I'll check for sure. Bob . . . ________________________________ Message 6 _____________________________________ Time: 01:53:38 PM PST US Subject: AeroElectric-List: Re: SD8 output at 28V? From: "digidocs" Bob, That's really helpful information. I currently have the 14V version and B&C told me that I could switch it to 28V by simply changing the regulator. It sounds like that may not be the case. (no pun intended) David Read this topic online here: http://forums.matronics.com/viewtopic.php?p=436018#436018 ________________________________ Message 7 _____________________________________ Time: 04:59:04 PM PST US From: "Weaver, Erich" Subject: AeroElectric-List: Power stabilizer wiring I had a conversation with the manufacturer today. Given the low amp draw for my specific use, he was comfortable with reducing the 12 amp fuse to 7.5 amp and eliminating the downstream 5 amp fuse. Not sure a 7.5 amp fuse is readily available, but will go with 10 if not. There is also no reason why the IPS can't be used as the sole source of power to the EFIS. There are multiple redundant paths built into the unit so that the power stabilizing capability could essentially vaporize and the unit would default to passing through available buss voltage, so there is very little risk of losing power to my EFIS. I do like the fact that this unit is small and maintenance free, unlike a backup battery that is more often used for this anti brownout purpose. This e-mail and any attachments contain URS Corporation confidential information that may be proprietary or privileged. If you receive this message in error or are not the intended recipient, you should not retain, distribute, disclose or use any of this information and you should destroy the e-mail and any attachments or copies. ________________________________ Message 8 _____________________________________ Time: 05:55:20 PM PST US From: "Bower, Bob" Subject: AeroElectric-List: N811HB analysis files Bob N. - In a recent post you referred us to http://www.aeroelectric.com/Re ference_Docs/Accidents/N811HB_Feb2008_LA-IVp/ for study. Many of the files in this folder are .wmv files, i.e. video files. Should t hese files be PDF files? Thanks. Bob Bower RV-6A builder ________________________________ Message 9 _____________________________________ Time: 06:17:18 PM PST US From: Jeff Luckey Subject: Re: AeroElectric-List: Power stabilizer wiring Erich, You appear to be interested in design and analysis so you may be interested in the attached document. It's a design where redundancy & brown-out prevention were initial design criteria and baked-in from the beginning - therefore it does not require bolting-on additional widgets. In addition it's surprisingly straight-forward. -Jeff On Monday, December 22, 2014 5:14 PM, "Weaver, Erich" wrote: I had a conversation with the manufacturer today. Given the low amp draw for my specific use, he was comfortable with reducing the 12 amp fuse to 7.5 amp and eliminating the downstream 5 amp fuse. Not sure a 7.5 amp fuse is readily available, but will go with 10 if not. There is also no reason why the IPS can't be used as the sole source of power to the EFIS. There are multiple redundant paths built into the unit so that the power stabilizing capability could essentially vaporize and the unit would default to passing through available buss voltage, so there is very little risk of losing power to my EFIS. I do like the fact that this unit is small and maintenance free, unlike a backup battery that is more often used for this anti brownout purpose. This e-mail and any attachments contain URS Corporation confidential information that may be proprietary or privileged. If you receive this message in error or are not the intended recipient, you should not retain, distribute, disclose or use any of this information and you should destroy the e-mail and any attachments or copies. ------------------------------------------------------------------------------------- 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.