---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 06/11/15: 14 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:34 AM - Re: E-bus feed switch rating (Justin Jones) 2. 04:55 AM - Re: E-bus feed switch rating (user9253) 3. 05:11 AM - Re: Switch Confusion (user9253) 4. 06:09 AM - Re: E-bus feed switch rating (Robert L. Nuckolls, III) 5. 06:29 AM - Re: E-bus feed switch rating (Robert L. Nuckolls, III) 6. 06:29 AM - Re: Switch Confusion (Robert L. Nuckolls, III) 7. 06:42 AM - Re: Re: Internal Shorting of Batteries (Jeff Page) 8. 09:11 AM - Re: Data acquisition tools? (Paul A. Fisher) 9. 11:38 AM - Newbie with PM alternator feed question (blues750) 10. 01:40 PM - Re: Newbie with PM alternator feed question (Robert L. Nuckolls, III) 11. 01:50 PM - Re: Data acquisition tools? (Robert L. Nuckolls, III) 12. 02:27 PM - Re: Data acquisition tools? (Paul A. Fisher) 13. 03:27 PM - Re: Newbie with PM alternator feed question (blues750) 14. 04:52 PM - Re: Data acquisition tools? (Charlie England) ________________________________ Message 1 _____________________________________ Time: 03:34:56 AM PST US From: Justin Jones Subject: Re: AeroElectric-List: E-bus feed switch rating I used one of these. http://www.aircraftspruce.com/catalog/elpages/pbcircuitbrkr2.php?clickkey=11597 > On Jun 10, 2015, at 14:15, ChrisJ wrote: > > > I'm using the Z-12 electrical schematic to wire my airplane, and I had a question about the E-bus feed switch rating. My E-bus will draw 22-30 amps depending on transient loads like flaps or boost pump. My diode will handle that just fine, but the toggles I bought from B&C are only rated to 15A. Do I need to hunt down an appropriately rated switch for this application? I searched the archives and didn't really find the answer. I can't be the first guy to put a few too many things on the E-bus can I?? > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=443368#443368 > > > > > > > > > > ________________________________ Message 2 _____________________________________ Time: 04:55:55 AM PST US Subject: AeroElectric-List: Re: E-bus feed switch rating From: "user9253" > What does the arc suppressor do? > Ross Mickey When current though an inductor (coil) is shut off, the collapsing magnetic field induces a high voltage that makes current flow in SAME direction as it was originally flowing. This principle is used to power spark plugs in engines. An analogy is to quickly shut off the flow of water in a pipe. The water tends to keep flowing due to inertia. Without some type of shock absorber, the pipes will hammer and bang. This principle is used to pump water without external power (hydraulic ram pump). Anyway, when current to a relay is shut off, the high induced voltage will arc across the open switch contacts, shortening the life of the switch. A diode connected across the coil will short out induced current and limit the voltage to about 1V. The arrow on the diode should point towards positive. The diode will not conduct while the relay is energized, but it will conduct induced current when the relay is de-energized. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=443391#443391 ________________________________ Message 3 _____________________________________ Time: 05:11:42 AM PST US Subject: AeroElectric-List: Re: Switch Confusion From: "user9253" > as determined by using my voltmeter between the poles Your ohmmeter analysis is correct. The voltmeter analysis is flawed. Voltage between two contacts of a switch indicates that the switch is open. A closed switch will have zero volts across its contacts. Use the circuit common point (ground) as the voltmeter reference point and measure again. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=443392#443392 ________________________________ Message 4 _____________________________________ Time: 06:09:05 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: E-bus feed switch rating At 05:15 PM 6/10/2015, you wrote: > >I'm using the Z-12 electrical schematic to wire my airplane, and I >had a question about the E-bus feed switch rating. My E-bus will >draw 22-30 amps depending on transient loads like flaps or boost >pump. My diode will handle that just fine, but the toggles I bought >from B&C are only rated to 15A. Do I need to hunt down an >appropriately rated switch for this application? I searched the >archives and didn't really find the answer. I can't be the first guy >to put a few too many things on the E-bus can I?? That is NOT an E-BUS . . . E stands for 'endurance'. The e-bus is intended to offer a fast-configuration to Plan-B . . . battery only, alternator-out operations . . .or perhaps reduced capabilities supported by a standby alternator like Z-13/8. The e-bus alternate feed offers a means by which the airplane can be powered-down to the minimum equipment needed for comfortable continuation of flight . . . preferably to the airport of intended destination. It's an energy management tool that must calls for (1) developing the minimalist list of support equipment and (2) planning for the energy needed. If you're battery-only, then your well advised to install and maintain a battery of KNOWN capacity that will support your e-bus loads for the endurance design goals. I like to plan to run out of fuel before I run out of watt-seconds. With no standby alternator, the typical ebus loads are 2-5 amps. With an SD-8 second alternator, e-bus can run 8+ amps . . . perhaps more and still SAVE the battery for descent and approach to landing. With an SD-20, you install Z-12 and don't even need an e-bus. Bob . . . ________________________________ Message 5 _____________________________________ Time: 06:29:10 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: E-bus feed switch rating At 05:33 AM 6/11/2015, you wrote: > > >I used one of these. > >http://www.aircraftspruce.com/catalog/elpages/pbcircuitbrkr2.php?clickkey=11597 Why a breaker/switch? Those are loaded with mechanical monkey motion to combine the functions. Rube Goldburg would be proud . . . if you don't NEED the circuit protection, then a plain vanilla switch is the better choice. Emacs! Bob . . . ________________________________ Message 6 _____________________________________ Time: 06:29:12 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Switch Confusion At 11:29 PM 6/10/2015, you wrote: >Ever since I found out that the 1-2-3 position on a simple 1-3 >switch ( or any other switch) varies in their location ( top to >bottom or bottom to top as referenced by the key hole), I am trying >to determine how the switches I have are configured. I assume that >the center pole is the common pole between the other two. I then >used my ohmmeter on an unconnected switch to check the resistance >between the center and the other two poles. I thought that when >the resistance read zero between two pole that this then indicated >the two were connect and became an ON position. I then attached the >wires and fired up the juice and low and behold the two poles that >showed zero resistance actually represented the OFF position as >determined by using my voltmeter between the poles and the two poles >that read 1.0 on my ohmmeter were actually the ON position. Take one apart and see how it works . . . Emacs! Bob . . . ________________________________ Message 7 _____________________________________ Time: 06:42:07 AM PST US From: Jeff Page Subject: Re: AeroElectric-List: Re: Internal Shorting of Batteries I left two standard automotive batteries connected to a single battery maintainer over the winter. The maintainer didn't have the capability of charging the batteries, but it just needed to maintain the float voltage. At some point during the winter, one of the cells in one of the batteries failed. This held both batteries at 10.5V for an extended period of time, so I ended up with 2 ruined batteries :-( Jeff Page Dream Aircraft Tundra #10 > Time: 02:47:49 PM PST US > From: "Robert L. Nuckolls, III" > Subject: Re: AeroElectric-List: Re: Internal Shorting of Batteries > > At 11:56 AM 6/9/2015, you wrote: >> >> Suppose that the attitude of an aircraft owner towards safety is >> somewhat lax. He knows that one of his two batteries is weak, > > Non-quantified . . . . weak by how much? One passes cap-check > at 80% and the other doesn't? One is new and the other doesn't > pass cap-check. Has the 'weak' battery become compromised due > to service extended beyond practical utilization? I understand > the hypothetical . . . but anyone conducting such experiments > in with daylight under the wheels is . . . well . . . > >> but does not replace it because he still has one good one, >> connected in parallel per Z-19. He goes flying and the weak >> battery develops a shorted cell. What symptoms would the pilot >> observe? Low voltage? High alternator output current? Both? None? > > Assuming a relatively robust alternator, 40+ amps, probably > just a rise in alternator output. The remaining 'good' cells > would be receiving an over-charge voltage . . . something > akin to charging a perfectly good battery at 17 volts or about > 2.88 volts per cell. Nothing earth shaking. Remaining cells are > at risk of venting and loosing water whereupon they stop > accepting a charge . . . and nothing happens. > > Shorted cell will dump all it's remaining energy into > the short. The rate of energy conversion to heat sets > the tone of the symptoms . . . but if the cell is so > badly damaged that it's chemistry has swelled and > produces a short, then there might not be much energy > available to produce spectacular symptoms. > > The fact that the accident airplane DID present with > a shorted cell raises lots of questions about that > battery's history and the quality of preventative > maintenance designed to prevent such occurances in > the first place. And what was the condition of the > 'good' battery. Certainly no shorted cell but was > it flight worthy? And what was the alternator > doing all this time? > > If he was flying without alternator and a single > battery that suffered a shorted cell, then yeah . . . > things could degrade in a hurry. Not necessarily > because of the shorted cell but because the battery > was so badly maintained that it suffered the short > with the remaining cells incapable of serviceable > performance. But a shorted cell battery paralleled with a > truly flight worthy battery and a working alternator > should not be an airplane crippling event. > > > Bob . . . ________________________________ Message 8 _____________________________________ Time: 09:11:13 AM PST US From: "Paul A. Fisher" Subject: Re: AeroElectric-List: Data acquisition tools? Thanks for the pointer. This looks promising! - Paul On 6/10/2015 10:59 AM, C&K wrote: > > http://www.dataq.com/products/di-145/#ordernow > That is about the best deal I've seen. Much cheaper and easier than > what I use. The software for display and analysis is almost more > important than what hardware you select. > Ken > ________________________________ Message 9 _____________________________________ Time: 11:38:59 AM PST US Subject: AeroElectric-List: Newbie with PM alternator feed question From: "blues750" Running a UL Power engine with 30A PM alternator with external R/R. Excess voltage dumped to ground via the thyristors as waste/heat. My question - if the thyristors fail and I have an over voltage condition, what is the recommended design way to disconnect/interrupt alternator output to the batteries or primary and secondary busses? Switch, switch/relay combo, I do need energy to the busses from the battery to run the ECU's and fuel pumps to keep the engine running. Specifics and general discussion appreciated. Thanks Dave Read this topic online here: http://forums.matronics.com/viewtopic.php?p=443406#443406 ________________________________ Message 10 ____________________________________ Time: 01:40:46 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Newbie with PM alternator feed question At 01:37 PM 6/11/2015, you wrote: > >Running a UL Power engine with 30A PM alternator with external >R/R. Excess voltage dumped to ground via the thyristors as waste/heat. This class of rectifier/regulator has never been used in this class of alternator . . . and fell from favor in small engine bikes and scooters years ago. They have been SERIES switched, rectifier/regulators for decades. >My question - if the thyristors fail and I have an over voltage >condition, what is the recommended design way to >disconnect/interrupt alternator output to the batteries or primary >and secondary busses? Switch, switch/relay combo, I do need energy >to the busses from the battery to run the ECU's and fuel pumps to >keep the engine running. Specifics and general discussion appreciated. See: http://tinyurl.com/7vp9g4e . . . for an exemplar methodology for disconnecting the a/c output of the PM alternator from the R/R during normal alternator shut-down and/or forced shutdown after an OV event. Bob . . . ________________________________ Message 11 ____________________________________ Time: 01:50:49 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Data acquisition tools? At 10:25 AM 6/10/2015, you wrote: >Our local EAA chapter is looking to invest in >something that can do data acquisition on a >flying aircraft.=C2 I figured this group would be >a good place to start.=C2 Technology in this area >seems to be moving quickly, so it seems like >there has to be a valid solution that we could try. Take a look at this product . . . http://tinyurl.com/n3roz5z I've used perhaps a dozen different pc base DAS products over the last 20 years. Every year you can do more for less. This particular offering comes with an excellent graphical user interface to boot! The downside is that while it records a LOT of data channels, it is hardware limited to 0-5 volt analog inputs. This means that for most measurements you'll need to craft some signal conditioning. Somewhere in the archives, I have a 6 or 8 channel amplifier board that mounts instrumentation amps and a component 'patch' area to install components that set gain and frequency roll off. The instrumentation amps even let you read 50mv, high-side shunts. I'll see if I can find it . . . I used a similar system to record some strain-gage data on a trim system failure investigation back about 1992. That DAS cost $100 and didn't have a GUI . . . had to massage the data in Excel/AutoCAD In this case, the singing and dancing side of the DAS hardware and software is dirt cheap. There will be some dish washing to take care of before it's a broadly useful system. Bob . . . ________________________________ Message 12 ____________________________________ Time: 02:27:20 PM PST US From: "Paul A. Fisher" Subject: Re: AeroElectric-List: Data acquisition tools? Thanks Bob. I would be interested if you find your amplifier board description. This looks cheap enough to buy just to play with it to see what it can do! - Paul On 6/11/2015 3:49 PM, Robert L. Nuckolls, III wrote: > At 10:25 AM 6/10/2015, you wrote: >> Our local EAA chapter is looking to invest in something that can do >> data acquisition on a flying aircraft. I figured this group would >> be a good place to start. Technology in this area seems to be >> moving quickly, so it seems like there has to be a valid solution >> that we could try. > > > Take a look at this product . . . > > http://tinyurl.com/n3roz5z > > I've used perhaps a dozen different pc base DAS > products over the last 20 years. Every year you > can do more for less. > > This particular offering comes with an excellent > graphical user interface to boot! > > The downside is that while it records a LOT of > data channels, it is hardware limited to 0-5 volt > analog inputs. This means that for most measurements > you'll need to craft some signal conditioning. > > Somewhere in the archives, I have a 6 or 8 channel > amplifier board that mounts instrumentation amps > and a component 'patch' area to install components > that set gain and frequency roll off. The instrumentation > amps even let you read 50mv, high-side shunts. > > I'll see if I can find it . . . > > I used a similar system to record some strain-gage > data on a trim system failure investigation back > about 1992. That DAS cost $100 and didn't have > a GUI . . . had to massage the data in Excel/AutoCAD > In this case, the singing and dancing side of > the DAS hardware and software is dirt cheap. > There will be some dish washing to take care > of before it's a broadly useful system. > > > Bob . . . > > ________________________________ Message 13 ____________________________________ Time: 03:27:27 PM PST US Subject: AeroElectric-List: Re: Newbie with PM alternator feed question From: "blues750" Thanks Bob...more confused and curious now. The system is described as a permanent magnet 3-phase alternator with a simple and reliable shunt type of regulator with fail safe characteristics. They further state "the thyristors in the shunt regulator actually short the generator windings to ground (dump the load) in a pulsating like fashion..." What class of of R/R and Alternator do I have? Or, better yet, what is the accurate way to refer to my system. Not sure what a series switched R/R is with respect to my system. Should I consider changing out my R/R for any reason? Trying to determine how to best (if required) implement a disconnect of some sort in the event an over voltage condition occurs. Trying to sort things out as I proceed and appreciate this forum and your literature! Dave Read this topic online here: http://forums.matronics.com/viewtopic.php?p=443415#443415 ________________________________ Message 14 ____________________________________ Time: 04:52:38 PM PST US From: Charlie England Subject: Re: AeroElectric-List: Data acquisition tools? On 6/11/2015 3:49 PM, Robert L. Nuckolls, III wrote: > At 10:25 AM 6/10/2015, you wrote: >> Our local EAA chapter is looking to invest in something that can do >> data acquisition on a flying aircraft. I figured this group would >> be a good place to start. Technology in this area seems to be >> moving quickly, so it seems like there has to be a valid solution >> that we could try. > > > Take a look at this product . . . > > http://tinyurl.com/n3roz5z > > I've used perhaps a dozen different pc base DAS > products over the last 20 years. Every year you > can do more for less. > > This particular offering comes with an excellent > graphical user interface to boot! > > The downside is that while it records a LOT of > data channels, it is hardware limited to 0-5 volt > analog inputs. This means that for most measurements > you'll need to craft some signal conditioning. > > Somewhere in the archives, I have a 6 or 8 channel > amplifier board that mounts instrumentation amps > and a component 'patch' area to install components > that set gain and frequency roll off. The instrumentation > amps even let you read 50mv, high-side shunts. > > I'll see if I can find it . . . > > I used a similar system to record some strain-gage > data on a trim system failure investigation back > about 1992. That DAS cost $100 and didn't have > a GUI . . . had to massage the data in Excel/AutoCAD > In this case, the singing and dancing side of > the DAS hardware and software is dirt cheap. > There will be some dish washing to take care > of before it's a broadly useful system. > > > Bob . . . > > From down under: http://geoffg.net/tft-maximite.html (lots of variations, too, with/without a screen) and from around there: http://www.ebay.com/itm/280916642088?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT Haven't used either one, but the Maximite is being used as an engine monitor by an Aussie running a rotary engine. I've got one of the ebay usb stick DACs, but haven't had time to actually play with it. Looks pretty easy to use with an android tablet, which is why I went ahead & bought one. 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