---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 03/25/03: 18 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:11 AM - Re: Fw: Push to Talk Switch Wiring (Tom & Cathy Ervin) 2. 06:16 AM - Re: Fw: Push to Talk Switch Wiring (Robert L. Nuckolls, III) 3. 06:18 AM - Re: Fw: Push to Talk Switch Wiring (Robert L. Nuckolls, III) 4. 06:56 AM - Re: alternator failure modes (Robert L. Nuckolls, III) 5. 07:06 AM - Re: alternator + fire? (Robert L. Nuckolls, III) 6. 08:23 AM - Re: alternator failure modes (MikeM) 7. 10:00 AM - starter brushes and burnt alternators (KahnSG@aol.com) 8. 10:19 AM - Stereo Wirin' (Mark Phillips) 9. 11:53 AM - Re: Motor Glider System Questions (Gerald Giddens) 10. 12:06 PM - Re: Stereo Wirin' (Robert L. Nuckolls, III) 11. 12:08 PM - Re: starter brushes and burnt alternators (Robert L. Nuckolls, III) 12. 12:32 PM - Re: Stereo Wirin' (Mark Phillips) 13. 02:44 PM - Re: Motor Glider System Questions (Robert L. Nuckolls, III) 14. 02:54 PM - starter considerations with EFIS/one and FADEC (TimRhod@aol.com) 15. 03:08 PM - Re: Motor Glider System Questions (Gerald Giddens) 16. 04:35 PM - Re: Fw: Push to Talk Switch Wiring (Tom & Cathy Ervin) 17. 06:49 PM - Hot Little Torch (Julia) 18. 07:49 PM - Is this a "good" battery for the price? (Tom...) ________________________________ Message 1 _____________________________________ Time: 02:11:02 AM PST US From: "Tom & Cathy Ervin" Subject: Re: Fw: AeroElectric-List: Push to Talk Switch Wiring --> AeroElectric-List message posted by: "Tom & Cathy Ervin" Charlie, I have a "Key Wire" from the audio panel to the jack but.........most harness I have seen also have a wire for the push to talk? I believe I can jump off the jack key wire and accomplish the same thing?? Tom in Ohio ----- Original Message ----- From: "Charlie & Tupper England" Subject: Re: Fw: AeroElectric-List: Push to Talk Switch Wiring > --> AeroElectric-List message posted by: Charlie & Tupper England > > Tom & Cathy Ervin wrote: > > >--> AeroElectric-List message posted by: "Tom & Cathy Ervin" > > > >List, I Haven't gotten any help on this problem yet? Has anybody faced > >this one? No help in the archives > > > >Thanks, Tom in Ohio > >----- Original Message ----- > >From: "Tom & Cathy Ervin" > >To: > >Subject: AeroElectric-List: Push to Talk Switch Wiring > > > > > > > > > >>--> AeroElectric-List message posted by: "Tom & Cathy Ervin" > >> > >> > > > > > > > >>List, > >> I have my Audio Panel PS-4000 wiring harness in place but they > >> > >> > >didn't make up separate wires for the Push to Talk Buttons? > > > > > >> One wire I know is the ground but wouldn't the other wire go > >> > >> > >to the "Key Wire" on the Microphone jack that the headset plugs into? > >Thanks for any help as the wiring is just about done. > > > > > >Tom in Ohio > > > Hi Tom, > > Do you mean that the harness has the key wire from the intercom to the > radio but not from the mic jack to the intercom? > > The PTT wire should leave the 'tip' terminal of the mic jack and go to > the 'PTT' or 'key' jack on the intercom. There will likely be a PTT > terminal on the intecom for the pilot's mic & each passenger's mic. The > intercom should have another terminal for a PTT wire leaving the > intercom & going to the radio. > > Does this help? > > Charlie > > ________________________________ Message 2 _____________________________________ Time: 06:16:00 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: Fw: AeroElectric-List: Push to Talk Switch Wiring --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 05:09 AM 3/25/2003 -0500, you wrote: >--> AeroElectric-List message posted by: "Tom & Cathy Ervin" > > >Charlie, I have a "Key Wire" from the audio panel to the jack >but.........most harness I have seen also have a wire for the push to talk? >I believe I can jump off the jack key wire and accomplish the same thing?? This is generally the case. PTT leads to microphones and PTT leads to wheel/stick mounted buttons are one in the same circuit. When only microphone jack PTT wiring is depicted, then additional buttons are wired to the >Tom in Ohio >----- Original Message ----- >From: "Charlie & Tupper England" >To: >Subject: Re: Fw: AeroElectric-List: Push to Talk Switch Wiring > > > > --> AeroElectric-List message posted by: Charlie & Tupper England > > > > > Tom & Cathy Ervin wrote: > > > > >--> AeroElectric-List message posted by: "Tom & Cathy Ervin" > > > > > > >List, I Haven't gotten any help on this problem yet? Has anybody faced > > >this one? No help in the archives > > > > > >Thanks, Tom in Ohio > > >----- Original Message ----- > > >From: "Tom & Cathy Ervin" > > >To: > > >Subject: AeroElectric-List: Push to Talk Switch Wiring > > > > > > > > > > > > > > >>--> AeroElectric-List message posted by: "Tom & Cathy Ervin" > > >> > > >> > > > > > > > > > > > >>List, > > >> I have my Audio Panel PS-4000 wiring harness in place but >they > > >> > > >> > > >didn't make up separate wires for the Push to Talk Buttons? > > > > > > > > >> One wire I know is the ground but wouldn't the other wire go > > >> > > >> > > >to the "Key Wire" on the Microphone jack that the headset plugs into? > > >Thanks for any help as the wiring is just about done. > > > > > > > > >Tom in Ohio > > > > > Hi Tom, > > > > Do you mean that the harness has the key wire from the intercom to the > > radio but not from the mic jack to the intercom? > > > > The PTT wire should leave the 'tip' terminal of the mic jack and go to > > the 'PTT' or 'key' jack on the intercom. There will likely be a PTT > > terminal on the intecom for the pilot's mic & each passenger's mic. The > > intercom should have another terminal for a PTT wire leaving the > > intercom & going to the radio. > > > > Does this help? > > > > Charlie > > > > > > Bob . . . |-------------------------------------------------------| | The man who does not read good books has no advantage | | over the man who cannot read them. | | - Mark Twain | |-------------------------------------------------------| ________________________________ Message 3 _____________________________________ Time: 06:18:11 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: Fw: AeroElectric-List: Push to Talk Switch Wiring --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 05:09 AM 3/25/2003 -0500, you wrote: >--> AeroElectric-List message posted by: "Tom & Cathy Ervin" > > >Charlie, I have a "Key Wire" from the audio panel to the jack >but.........most harness I have seen also have a wire for the push to talk? >I believe I can jump off the jack key wire and accomplish the same thing?? This is generally the case. PTT leads to microphones and PTT leads to wheel/stick mounted buttons are one in the same circuit. When only microphone jack PTT wiring is depicted, then additional buttons are wired to the (. . . oops, too fast on the keys this morning, launched the message before it was finished) to the microphone jack. See page 11 of http://216.55.140.222/Catalog/avionics/760imB.pdf Bob . . . ________________________________ Message 4 _____________________________________ Time: 06:56:29 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: alternator failure modes --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >I have flight checked this condition several times with my internally >regulated alternator, a 40A Denso from Niagra with all brackets etc, for >$225. > >I have a 35A circuit breaker switch in line with the B lead to the main bus. >When opened in flight, the alternator loses no smoke. Same with turning off >the regulator power. It would be interesting to get a voltmeter reading on the alternator side of the breaker when it's opened in cruising flight . . . although this DOES pose the risk of diode failure, I believe it to be low. If you've already done this without taking a voltage reading, then the risk is VERY small. > I have my OV protection hooked up to that fellow, but >probably should also have the contactor that Bob recommends. I say probably >because, I am from Missouri, and haven=B9t been shown the failure mode >wherein the field gets goosed by some internal short from the B. I've seen this happen only once . . . about 35 years ago on a Mooney. It was the by-product of poor mechanical design in a low-cost alternator Mooney was trying . . . they abandoned that device for this and other reasons. Given the manner in which modern alternator are assembled mechanically, this is not a concern. >P. S. Please don=B9t confuse me with any one who is willing to debate this >sort of thing. > >I am delighted with the value of the niagra product, and its functino and >reliability has been great. If I were startign over however, I would have >to very carefully consider the B&C which is a giant step up from the =B3out >of the box=B2 Denso. thank you for sharing this data. BTW, the 35 A breaker concerns me . . . a 40A alternator will put out more than 40A when cold. The 60A breaker on most single engine aircraft is DESIGNED to nuisance trip when the stock, 60A alternator is feeling frisky. You might keep an eye open for a 50A breaker to put in that slot when it becomes convenient. Bob . . . ________________________________ Message 5 _____________________________________ Time: 07:06:33 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: alternator + fire? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:13 AM 3/24/2003 -0800, you wrote: >--> AeroElectric-List message posted by: Scott Bilinski > > > From a previous post. > >" don't have a problem with a failed alternator causing the OVM to trip and >then the alternator self-distructing as long asit doesn't catch fire." > >I know quite a bit aobut cars and have rebuilt numerous Alt's years ago. I >have never ran across and Alt that has caught fire. This is really rare right? Alternators don't catch fire. They DO burn up windings with liberation of some smelly smoke but they could conceivably eject bits of sparking materials if a wire burns open but they do not burst into sustained flames. Given their locations on engines, the risk of propagating burning debris onto other combustibles under the cowl is zip . . . we take pains to NOT have combustibles under the cowl . . . right? Thousands of airplanes have come down in the history of aviation due to failure of an alternator's ability to power critical items for sustained flight in poorly designed and/or maintained systems . . . I'm aware of no accident where the alternator set the airplane on fire. I'll ask the wreckage-wiennies at RAC if they're ever seen it. I'm certain the answer is going to be "no". Bob . . . ________________________________ Message 6 _____________________________________ Time: 08:23:03 AM PST US From: MikeM Subject: Re: AeroElectric-List: alternator failure modes --> AeroElectric-List message posted by: MikeM Bin watchin' the discussion about failure modes of two-terminal (internally regulated) alternators. I use Prestolite DOFxxxx style alternators, which have four external terminals: Field1, Field2, B (output), and case-ground. As such, they are amenable to external control and shutdown. Because they bring out both field slip-rings, you can even use external high-side (Chrysler), or low-side (Ford, Motorola) Voltage Regulators (VR). OverVoltage Protection (OVP) can be accomplished by interupting the field current path either by using a series switch, or a shunt crowbar which "blows" the field breaker... If I were to use one of the modern two-terminal marvels, I would take it apart to disconnect the internal connection between the B terminal (output) and the internal VR. If I wanted to use the internal VR, I would bring the VR input wire out of the alternator's case so that I could connect an external OVP and a pullable Field Breaker between the B terminal and the internal VR. Alternatively, I would disconnect both the input and output from the internal VR, bring out the wire from the field slip-ring, and revert to my own tried and true external VR and OVP. I made a modification similar to this to the internally regulated alternator in my boat. The goal was to be able to use an external "smart", remote-sensing VR, which is capable of "equalizing" the boat batteries by artifically boosting the charge voltage at my will. It was easy to disassemble the alternator to isolate the internal regulator... Mike Mladejovsky ________________________________ Message 7 _____________________________________ Time: 10:00:10 AM PST US From: KahnSG@aol.com Subject: AeroElectric-List: starter brushes and burnt alternators --> AeroElectric-List message posted by: KahnSG@aol.com The starter brush dimensions for a Delco-Remy model #1109657 are: .500 x .750 x .250 in. The part numbers are: Standard RX52 Delco D754 Niehoff DR95E I don't know if they are available. They fit industrial and Nash/American starters up to 1951. We also see many burned alternators from cars. Mostly the the diode assy. and reg. in CS130 and CS144 series Delco. (late 1980's and up GM) The B lead connector burns up on the Ford int. reg. alternators quite often, including enough fire to melt other wiring that is close to the alt. Steve Springfield Auto Parts Co., Inc. ________________________________ Message 8 _____________________________________ Time: 10:19:57 AM PST US From: Mark Phillips Subject: AeroElectric-List: Stereo Wirin' --> AeroElectric-List message posted by: Mark Phillips I've been re-arranging my wiring (again! Ain't ACAD a wonderful thang?) attempting to accommodate both mono and stereo headset jacks for each passenger and think I "may" have a reasonable solution, but I'd like to run it by you A-list audio genius's. (genii? or did I blow the apostrophe on that one?) Here goes: In order to have both channels available to a mono headset, ya gotta tie 'em together, no? I have located a jack in the Mouser inventory that has a double switch on the tip contact- it is referred to as a "transfer circuit". It's the only one I could find that has a NO contact, or a least it looks like it does. It is part# 502-13A, top of page 458 in the current catalog, circuit diagram "CC" or see it here: http://www.mouser.com//index.cfm?handler=fra_pdfset&dir=613&pdffile=458 or go to: http://mouser.com/ and search for part# 502-13A It looks like I could use the NO contacts to short L & R leads (wired from the stereo jack) when the plug is inserted. Voila'- both channels. If you inserted a stereo plug, you'd only get one side, but it wouldn't hurt anything. Using this jack would make both passengers' headsets mono, but hey- what's another stereo headset cost, anyway? Question 1: Is this an appropriate method or is there a more functional way of doing this? The only problem I see it that if you plugged a mono headset into the STEREO jack, it would short the channel wired to the ring to ground. Question 2: Is this a bad thing? Or is the radio protected somehow from having audio out grounded with no load? I'm going to attempt to "roll my own" audio isolation amp as shown in the Connection and there is a 10uF capacitor in the audio out- is this critter there to protect the output from going to ground if it is shorted out? I could placard the stereo jack against mono insertion, but this may make female passengers nervous! A wiring we will go at The PossumWorks in TN Mark - do not archive kindergarden-level 'lectronic questions! ________________________________ Message 9 _____________________________________ Time: 11:53:59 AM PST US Subject: Re: AeroElectric-List: Motor Glider System Questions From: Gerald Giddens --> AeroElectric-List message posted by: Gerald Giddens > From: "Robert L. Nuckolls, III" > Reply-To: aeroelectric-list@matronics.com > Date: Mon, 24 Mar 2003 14:50:50 -0600 > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: Motor Glider System Questions > > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > At 08:21 AM 3/21/2003 -0800, Gerald Giddens wrote: > >> Bob, >> I have entered a subscription to matronics as you suggest. I hope I will be >> able navigate the site - an not be plaged by attempts to access my computer >> system as you lamented on your site. > > . . . not sure what your concerns are . . . there are no > potential risks to your computer to browse the matronics archives > or subscribe to any of their supported lists . . . Enough said > > >> I was able to print Z-13 - This was the schematic that I was first drawn to. >> The nature of a motorglider flight is motored flight then a transition to >> soaring flight - engine off - and the subsequent return for powered flight >> for a return home. This poses some interesting battery power conservation >> situations. Two batteries has been the main focus. Primarily concern is >> the ability to insure adequate power for engine restart. Engine restart is >> the #2 absolute requirement after the structural integrity of the airframe. >> A send alternator/dynamo has not been considered but is now on the table. > > What size engine are we talking about? Do you have any current > draw values for the starter? I have a Lycoming 150 HP(Low Compression 7:1) with a factory supplied Light Weight Starter. Will get starter information info from data plate if available - project is 1+ hour from home. I have a constant speed propeller with unfeathering accumulator - Hope is to be able to unfeather and "dive start", or at least assist battery start, after motorless soaring flight. The 2 battery installation with manual selection is planned. The only automatic function is the placement of a diode to allow charging of the soaring battery when the engine alternator is on line. I have not planned to parallel the batteries, however another parallel position could easily be added to the manual rotary battery selector switch. The thought is that the "soaring" battery will power the instrumention/radio etc buss to be used for soaring without accessing the engine start battery. While the engine is running, the soaring battery will be charged - a diode is planed to allow charging but not allow discharge of the soaring battery while the engine is running. What happens if one battery-(Soaring) is depleted and it is paralleled with a charged (engine) battery? Have no experience but it does not sound like a good idea to me. Also the hope is to be able to "dive start", if necessary after motorless flight with assist from engine battery as available. > >> My immediate need is info about determining the length to use in determining >> voltage drop. I could not find a clear explanation in 43.13. The >> explanation from an on line EAA tech differed from what I believe was on one >> of your web articles. I interpret what you said is that the wire length to >> use is that from the source , circuit breaker or buss connection, to the >> consuming device plus the wire length to a ground connection. 43.13 seems >> to indicate that, in an aluminum structure, the resistance drop from the >> ground connection to the battery ground to airframe is negligable. > > Unless you're building a large composite aircraft or a huge > aluminum airplane, voltage drops are not a driving consideration > for wire size. Table 11-9 in AC43-13 or Figure 8-3 of the > 'Connection can be consulted for recommended wires at the various > current ratings. Fuses/breakers should be the same size or > smaller than the recommended continuous current level. I am not sure if I am huge - it is a 2 place tandem, all aluminum airframe with a high aspect wing - span 63 feet, fuselage spinner to tail cone 33 feet. Gross weight may approach 2400 pounds. Airframe is 95% complete. Depending to ground wire and/or airframe bond answer (see below) some circuit lengths may have a voltage drop problem - however the few circuits involved could be solved by increasing wire size. > > >> Another question is the sizing of the main power feed from the battery (aft >> baggage compartment) to the the main buss, estimated at 16 feet in my case, >> and the power feed to the starter - another 8 feet from the main power buss >> to starter relay and on to the starter. I am wondering about installing a >> ground conductor from the starter back to the additional engine ground >> connection on the firewall and possibly going onto the main ground buss at >> the instrument panel. Are we now at 32 feet for voltage drop? What about >> extending the ground wire another 16 feet to the battery(ies)? > > With the battery that far from the engine, make all cranking > circuit wires at least 2AWG. Welding cable will work fine. > Run braided number from crankcase to firewall ground stud, > bring battery (-) to this same stud via 2AWG wire. Let's > talk some more about how this airplane is used . . . you > may want to consider a dual battery installation. Would it make sense to bond/jumper all consuming devices to the airframe in addition to a ground wire from each device to a ground buss installed in the #2 ground wire return to the battery? In addition to the firewall and front cockpit ground buss, I planned to put a ground buss at the aft passenger panel, in the #2 ground return to the battery location and connect grounds from the aft PAX panel. Electrical items in the wing would ground in this aft buss. A 2 battery installation is definitely being installed. The mission of the Motorglider is to provide a 2 place aircraft capable of "light IFR" cross country powered flight allowing departure from a city metropolis to an area, where soaring flight is practical, and return. The aircraft is designed to have a glide ratio approaching 30:1. Fuel capacity is 40 gallons, however that amount would not normally be carried. The airframe is a conventional tail dragger with a mechanically retractable main (2 wheel) landing gear. The outer 13 feet wing panels fold over the top and rest on top of the inboard wing. There is adequate power to tow sailplanes, if or when a tow hook is installed. > > Bob . . . Thank You for your input Jerry > > > > > ________________________________ Message 10 ____________________________________ Time: 12:06:55 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Stereo Wirin' --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >Question 1: Is this an appropriate method or is there a more functional >way of doing this? Sounds like it ought to work. >The only problem I see it that if you plugged a mono headset into the >STEREO jack, it would short the channel wired to the ring to ground. Even with DC blocking, some folks audio output stages might not like the increased output load. The LM386 will be okay I think. Of course, shorting one headset station's audio output channel to ground would kill them all. >Question 2: Is this a bad thing? Or is the radio protected somehow from >having audio out grounded with no load? I'm going to attempt to "roll >my own" audio isolation amp as shown in the Connection and there is a >10uF capacitor in the audio out- is this critter there to protect the >output from going to ground if it is shorted out? Yes . . . that capacitor is probably undersized . . . don't order parts until I get finished with the prototype. I've got the board stuffed. Will try to get it powered up this evening. . . >I could placard the stereo jack against mono insertion, but this may >make female passengers nervous! I usually put a toggle switch next to the jack to flip between stereo and monaural operation. Bob . . . ________________________________ Message 11 ____________________________________ Time: 12:08:16 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: starter brushes and burnt alternators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > >We also see many burned alternators from cars. >Mostly the the diode assy. and reg. in CS130 and CS144 series Delco. (late >1980's and up GM) >The B lead connector burns up on the Ford int. reg. alternators quite often, >including enough fire to melt other wiring that is close to the alt. Are any of these off-shore manufactured alternators . . . i.e. obviously ND, Mitsubishi, et. als? What's been your experience/observation with ND alternators? Bob . . . ________________________________ Message 12 ____________________________________ Time: 12:32:17 PM PST US From: Mark Phillips Subject: Re: AeroElectric-List: Stereo Wirin' --> AeroElectric-List message posted by: Mark Phillips > . . . don't order parts until I get finished with the prototype. I've > got the board stuffed. Will try to get it powered up this > evening. . . Outstanding- looking forward to it! > I usually put a toggle switch next to the jack to flip > between stereo and monaural operation. That's what I was looking for- the obvious solution! (duh- now publicly obvious why the big bux elude me!!!) Thank you sir... Mark Phillips - do not archive - ________________________________ Message 13 ____________________________________ Time: 02:44:53 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Motor Glider System Questions --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > What size engine are we talking about? Do you have any current > > draw values for the starter? > >I have a Lycoming 150 HP(Low Compression 7:1) with a factory supplied Light >Weight Starter. Will get starter information info from data plate if >available - project is 1+ hour from home. > >I have a constant speed propeller with unfeathering accumulator - Hope is to >be able to unfeather and "dive start", or at least assist battery start, >after motorless soaring flight. The 2 battery installation with manual >selection is planned. The only automatic function is the placement of a >diode to allow charging of the soaring battery when the engine alternator is >on line. No diode is necessary. A figure Z-11 with a second battery sounds like the cleanest system . . . or Z-13 . . . it's really easy to add the second alternator if you think you'd like to have the second engine driven power source. >I have not planned to parallel the batteries, however another parallel >position could easily be added to the manual rotary battery selector switch. >The thought is that the "soaring" battery will power the instrumention/radio >etc buss to be used for soaring without accessing the engine start battery. >While the engine is running, the soaring battery will be charged - a diode >is planed to allow charging but not allow discharge of the soaring battery >while the engine is running. For Z-11/13 with two batteries, each battery has it's own master switch. Both on for cranking and powered flight. Turn e-bus switch ON and both battery masters off for soaring flight . . . run soaring loads from e-bus (main battery only). >What happens if one battery-(Soaring) is depleted and it is paralleled with >a charged (engine) battery? Have no experience but it does not sound like a >good idea to me. Also the hope is to be able to "dive start", if necessary >after motorless flight with assist from engine battery as available. Doesn't hurt a thing. If main battery is depleted before engine start (have you figured what your soaring loads are?) it represents no big load on the cranking battery when it comes time to start the engine. Just close both battery master switches and hit the starter. With dual, well maintained batteries, the likelihood of EVER having to air-start the engine is zip (unless you've got a less than the best lightweight starter . . . then the risk is slightly greater than zip). >I am not sure if I am huge - it is a 2 place tandem, all aluminum airframe >with a high aspect wing - span 63 feet, fuselage spinner to tail cone 33 >feet. Gross weight may approach 2400 pounds. Airframe is 95% complete. >Depending to ground wire and/or airframe bond answer (see below) some >circuit lengths may have a voltage drop problem - however the few circuits >involved could be solved by increasing wire size. Run 2AWG wire from engine to batteries both ways . . . it will be fine. >Would it make sense to bond/jumper all consuming devices to the airframe in >addition to a ground wire from each device to a ground buss installed in the >#2 ground wire return to the battery? In addition to the firewall and front >cockpit ground buss, I planned to put a ground buss at the aft passenger >panel, in the #2 ground return to the battery location and connect grounds >from the aft PAX panel. Electrical items in the wing would ground in this >aft buss. Airframes hold wings and engine together, wires crank engines and run radios. Except for local grounding of certain remote items like nav lights, strobe power supply, landing/taxi lights and pitot heat, all other stuff is best carried on its own wiring sized to the task. 2AWG fat wires and a pair of 17 a.h. batteries is going to give you excellent cranking performance and reliability. >A 2 battery installation is definitely being installed. > >The mission of the Motorglider is to provide a 2 place aircraft capable of >"light IFR" cross country powered flight allowing departure from a city >metropolis to an area, where soaring flight is practical, and return. The >aircraft is designed to have a glide ratio approaching 30:1. Fuel capacity >is 40 gallons, however that amount would not normally be carried. The >airframe is a conventional tail dragger with a mechanically retractable main >(2 wheel) landing gear. The outer 13 feet wing panels fold over the top and >rest on top of the inboard wing. There is adequate power to tow sailplanes, >if or when a tow hook is installed. Figure Z-11/13 with second battery (Z-30 but no aux battery bus) will probably give you reliability and convenience far better than anything else flying. Bob . . . ________________________________ Message 14 ____________________________________ Time: 02:54:27 PM PST US From: TimRhod@aol.com Subject: AeroElectric-List: starter considerations with EFIS/one and FADEC --> AeroElectric-List message posted by: TimRhod@aol.com Bob and others: Ive been thinking of solutions to some of the things=A0 we have been discussing concerning voltage drop when starting FADEC engines. Also concern over voltage spikes=A0 or low voltage problems with the EFIS/ONE=A0 during starting.=A0 Here is what I came up with.=A0 Using Z-14 DBDA=A0 Put all avionics one one=20bus. For me I think this will be a avionics bus with quad feed.=A0 One from main=20bus through diode and avionics master switch. Second from Alternate bus through diode and avionics secondary master switch. Master switches are included in case EFIS systems need isolated as Greg Ricktor seems to think they should be. Third and fourth essential feeds from main batt buss and alternate batt buss on one switch that would choose one or the other.=A0 Cross feed contactor will not have starter switch included. Starter switch will be seperate. Here is how I envision it working.=A0 During start up sequence the avionics bus can be feed through the alternative electrical system. So the Efis/One is powered up from that source. Also the FADEC ignition is powered from the Alternate battery. The main battery is used to start the engine The cross feed is kept open at this point so the two electrical systems never affect each other. If you needed both batteries to start you would not turn on avionics bus until engine started. You wouldnt have you oil pressure immediatly but this shouldnt be a common occurance to need both batteries for starting. It seem to me that this allows the Efis/One and the FADEC ing. to be at 12.5 volts continually during engine start-up.=A0 What do you think? ________________________________ Message 15 ____________________________________ Time: 03:08:30 PM PST US Subject: Re: AeroElectric-List: Motor Glider System Questions From: Gerald Giddens --> AeroElectric-List message posted by: Gerald Giddens > From: Gerald Giddens > Reply-To: aeroelectric-list@matronics.com > Date: Tue, 25 Mar 2003 11:50:18 -0800 > To: > Subject: Re: AeroElectric-List: Motor Glider System Questions > > --> AeroElectric-List message posted by: Gerald Giddens > > > >> From: "Robert L. Nuckolls, III" >> Reply-To: aeroelectric-list@matronics.com >> Date: Mon, 24 Mar 2003 14:50:50 -0600 >> To: aeroelectric-list@matronics.com >> Subject: AeroElectric-List: Motor Glider System Questions >> >> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >> >> >> At 08:21 AM 3/21/2003 -0800, Gerald Giddens wrote: >> >>> Bob, >>> I have entered a subscription to matronics as you suggest. I hope I will be >>> able navigate the site - an not be plaged by attempts to access my computer >>> system as you lamented on your site. >> >> . . . not sure what your concerns are . . . there are no >> potential risks to your computer to browse the matronics archives >> or subscribe to any of their supported lists . . . > > Enough said > >> >> >>> I was able to print Z-13 - This was the schematic that I was first drawn to. >>> The nature of a motorglider flight is motored flight then a transition to >>> soaring flight - engine off - and the subsequent return for powered flight >>> for a return home. This poses some interesting battery power conservation >>> situations. Two batteries has been the main focus. Primarily concern is >>> the ability to insure adequate power for engine restart. Engine restart is >>> the #2 absolute requirement after the structural integrity of the airframe. >>> A send alternator/dynamo has not been considered but is now on the table. >> >> What size engine are we talking about? Do you have any current >> draw values for the starter? > > I have a Lycoming 150 HP(Low Compression 7:1) with a factory supplied Light > Weight Starter. Will get starter information info from data plate if > available - project is 1+ hour from home. > > I have a constant speed propeller with unfeathering accumulator - Hope is to > be able to unfeather and "dive start", or at least assist battery start, > after motorless soaring flight. The 2 battery installation with manual > selection is planned. The only automatic function is the placement of a > diode to allow charging of the soaring battery when the engine alternator is > on line. > > I have not planned to parallel the batteries, however another parallel > position could easily be added to the manual rotary battery selector switch. > The thought is that the "soaring" battery will power the instrumention/radio > etc buss to be used for soaring without accessing the engine start battery. > While the engine is running, the soaring battery will be charged - a diode > is planed to allow charging but not allow discharge of the soaring battery > while the engine is running. > > What happens if one battery-(Soaring) is depleted and it is paralleled with > a charged (engine) battery? Have no experience but it does not sound like a > good idea to me. Also the hope is to be able to "dive start", if necessary > after motorless flight with assist from engine battery as available. >> >>> My immediate need is info about determining the length to use in determining >>> voltage drop. I could not find a clear explanation in 43.13. The >>> explanation from an on line EAA tech differed from what I believe was on one >>> of your web articles. I interpret what you said is that the wire length to >>> use is that from the source , circuit breaker or buss connection, to the >>> consuming device plus the wire length to a ground connection. 43.13 seems >>> to indicate that, in an aluminum structure, the resistance drop from the >>> ground connection to the battery ground to airframe is negligable. >> >> Unless you're building a large composite aircraft or a huge >> aluminum airplane, voltage drops are not a driving consideration >> for wire size. Table 11-9 in AC43-13 or Figure 8-3 of the >> 'Connection can be consulted for recommended wires at the various >> current ratings. Fuses/breakers should be the same size or >> smaller than the recommended continuous current level. > > I am not sure if I am huge - it is a 2 place tandem, all aluminum airframe > with a high aspect wing - span 63 feet, fuselage spinner to tail cone 33 > feet. Gross weight may approach 2400 pounds. Airframe is 95% complete. > Depending to ground wire and/or airframe bond answer (see below) some > circuit lengths may have a voltage drop problem - however the few circuits > involved could be solved by increasing wire size. >> >> >>> Another question is the sizing of the main power feed from the battery (aft >>> baggage compartment) to the the main buss, estimated at 16 feet in my case, >>> and the power feed to the starter - another 8 feet from the main power buss >>> to starter relay and on to the starter. I am wondering about installing a >>> ground conductor from the starter back to the additional engine ground >>> connection on the firewall and possibly going onto the main ground buss at >>> the instrument panel. Are we now at 32 feet for voltage drop? What about >>> extending the ground wire another 16 feet to the battery(ies)? >> >> With the battery that far from the engine, make all cranking >> circuit wires at least 2AWG. Welding cable will work fine. >> Run braided number from crankcase to firewall ground stud, >> bring battery (-) to this same stud via 2AWG wire. Let's >> talk some more about how this airplane is used . . . you >> may want to consider a dual battery installation. > > Would it make sense to bond/jumper all consuming devices to the airframe in > addition to a ground wire from each device to a ground buss installed in the > #2 ground wire return to the battery? In addition to the firewall and front > cockpit ground buss, I planned to put a ground buss at the aft passenger > panel, in the #2 ground return to the battery location and connect grounds > from the aft PAX panel. Electrical items in the wing would ground in this > aft buss. > > A 2 battery installation is definitely being installed. > > The mission of the Motorglider is to provide a 2 place aircraft capable of > "light IFR" cross country powered flight allowing departure from a city > metropolis to an area, where soaring flight is practical, and return. The > aircraft is designed to have a glide ratio approaching 30:1. Fuel capacity > is 40 gallons, however that amount would not normally be carried. The > airframe is a conventional tail dragger with a mechanically retractable main > (2 wheel) landing gear. The outer 13 feet wing panels fold over the top and > rest on top of the inboard wing. There is adequate power to tow sailplanes, > if or when a tow hook is installed. > > >> >> Bob . . . > Thank You for your input > Jerry >> >> >> >> >> > > > > > > ________________________________ Message 16 ____________________________________ Time: 04:35:09 PM PST US From: "Tom & Cathy Ervin" Subject: Re: Fw: AeroElectric-List: Push to Talk Switch Wiring --> AeroElectric-List message posted by: "Tom & Cathy Ervin" Thanks Bob......As always clear, concise information! I have your book also and it has been a great help for this Rookie. Wiring is almost done and the smoke is in the wires so far. Tom in Ohio ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: Fw: AeroElectric-List: Push to Talk Switch Wiring > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 05:09 AM 3/25/2003 -0500, you wrote: > >--> AeroElectric-List message posted by: "Tom & Cathy Ervin" > > > > > >Charlie, I have a "Key Wire" from the audio panel to the jack > >but.........most harness I have seen also have a wire for the push to talk? > >I believe I can jump off the jack key wire and accomplish the same thing?? > > This is generally the case. PTT leads to microphones and > PTT leads to wheel/stick mounted buttons are one in the > same circuit. When only microphone jack PTT wiring is > depicted, then additional buttons are wired to the > > (. . . oops, too fast on the keys this morning, launched > the message before it was finished) > > to the microphone jack. See page 11 of > http://216.55.140.222/Catalog/avionics/760imB.pdf > > Bob . . . > > ________________________________ Message 17 ____________________________________ Time: 06:49:10 PM PST US From: Julia Subject: AeroElectric-List: Hot Little Torch --> AeroElectric-List message posted by: Julia I was in Radio Shack today and picked up one of their Mini Butane-Powered Soldering Irons - #64-2188 - for $19.99. WOW what a neat tool! I highly recommend getting one of these. I have no patience for waiting for a soldering iron to warm up - I was using a full sized plumbers torch. That worked fine for all but small items like the potentiometer on the light dimmer (no longer a potentiometer) - but this torch is really slick. It comes with a blow torch tip (which I plan to use) and then a soldering tip. The flame is very small and has pin point accuracy - i'm impressed - go get one! --------------------------------- ________________________________ Message 18 ____________________________________ Time: 07:49:48 PM PST US From: "Tom..." Subject: AeroElectric-List: Is this a "good" battery for the price? --> AeroElectric-List message posted by: "Tom..." Hiya Mr. Bob, I found these battries what do you think of the last one, the surplus "HAWKER G13EP" they actually weigh 10.8 Lbs. at: http://surplusev.com/ I got two including shipping to me for $60.oo total ! What do ya think for the price. Tom...