---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 11/25/05: 16 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:13 AM - gps displays (bob noffs) 2. 05:14 AM - gps install under AC 20 138A () 3. 10:22 AM - Re: Aviation headset substitute for testing (Robert L. Nuckolls, III) 4. 01:10 PM - Re:gps install under AC 20 138A (CardinalNSB@aol.com) 5. 01:34 PM - Re: Dual Alternator single battery question (Robert L. Nuckolls, III) 6. 01:40 PM - Re: Low Temps (was gps display) (Eric M. Jones) 7. 03:55 PM - Re: Re:gps install under AC 20 138A (BobsV35B@aol.com) 8. 06:13 PM - Re: Re:gps install under AC 20 138A (G McNutt) 9. 07:04 PM - Re: Re:gps install under AC 20 138A (BobsV35B@aol.com) 10. 07:35 PM - Re: RF Radiation (Robert L. Nuckolls, III) 11. 08:03 PM - high brightness LEDs (Carlos Sa) 12. 08:36 PM - Re: high brightness LEDs (Scott) 13. 10:13 PM - Cellphone-aviation Headset Interface (Joe Dubner) 14. 10:13 PM - P-mag Which Bus? (Pete Howell) 15. 10:15 PM - Re: Latching power relays? (Bob how about NO relays?) () 16. 10:20 PM - Re: Latching power relays? (Bob how about NO relays?) () ________________________________ Message 1 _____________________________________ Time: 04:13:17 AM PST US From: "bob noffs" Subject: AeroElectric-List: gps displays --> AeroElectric-List message posted by: "bob noffs" Hi Bob, Here is a good one. A friend was told by garmin that the cold could permanently damage the display on his gps. He bought a lowrance this summer and checked into this with lowrance. After a lot of evasion and double talk it finally came out that their display could be damaged too. I think below about 0 deg. f. How do automobiles get away with it? Every airplane with a glass panal cant be kept in a heated hanger . I see 25deg F below zero every year where I live. Any thoughts? Bob Noffs ________________________________ Message 2 _____________________________________ Time: 05:14:35 AM PST US From: Subject: AeroElectric-List: gps install under AC 20 138A --> AeroElectric-List message posted by: Responding to AeroElectric-List message previously posted by: CardinalNSB@aol.com <> 11/25/2005 Hello Skip, We need to know whether this is a type certificated airplane or an amateur built experimental. Makes a huge difference in what you do and how you do it. OC ________________________________ Message 3 _____________________________________ Time: 10:22:52 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Re: Aviation headset substitute for testing --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:29 AM 11/25/2005 -0500, you wrote: >--> AeroElectric-List message posted by: CardinalNSB@aol.com > >Hi, I am ready to install the intercom/wiring but I don't want to buy >headphones until I am ready to fly. Can I simply use a small >speaker with an >inline resister to total 150 ohms per side? Any tricks? thanks, skip >simpson The problem is not "impedance" but POWER. Power to your headphones is on the order of tens of milliwatts. Power to a speaker may be as much as a watt to be heard over cabin noise. If you're talking about a test environment in your shop, you MIGHT hear enough out of a small speaker to show that the system works . . . but you'd be better off using a pair of el-cheeso entertainment headsets that are already configured for low-power, tight-to-the-ear coupling. They're generally on the order of 30 ohm devices and won't hurt your intercom. You can get a pair at RS for a few dollars. If you wanted to make these "look" like aviation headsets, put 100 ohms in series with each side . . . you'll need to turn up the volume a little. Bob . . . ________________________________ Message 4 _____________________________________ Time: 01:10:38 PM PST US From: CardinalNSB@aol.com Subject: AeroElectric-List: Re:gps install under AC 20 138A --> AeroElectric-List message posted by: CardinalNSB@aol.com Thanks for the replies. I should have been clear, I am working on a certificated aircraft. It was my understanding that experimentals did not need FAA approval. I want to wire a ki202 cdi directly to a Garmin 300xl, and use either Elecro Mech switch/lights or some generic switches and lights. The Garmin manual says that lights and switches are required but does not specify the required part numbers (they do list their annunciators and the Mid-Continent part numbers as "Optional"). I read AC 20 138A as making this a minor modification. Of course the local radio shop says all gps installs are major, that there are no minor installs, my ap said he is willing to sign off as a minor install but I want to be on safe ground. Thanks, Skip ________________________________ Message 5 _____________________________________ Time: 01:34:49 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Dual Alternator single battery question --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:39 PM 11/19/2005 -0600, you wrote: >--> AeroElectric-List message posted by: "Tammy Goff" > >I have a dual alternator (40 amp and a 20 amp from B&C) Z-12 schematic. I >have the OV protective voltage regulators from B&C installed. The fellow >that I am working with would like to wire the system where the silicone >diode is left out and there is no essential bus. There would be a on off >switch for each alternator. My question is what would happen if both >alternators were "on" at the same time? They would both be feeding into >the avionics and the regular bus at the same time. Would those expensive >voltage regulators or other part go up in smoke or would things run >without difficulty? Thanks, George Have your "helper" give me a call (316) 685-8617. I find it mildly irritating that participants on this list find themselves cast in the role of mediator between partners and hangar mates (dispensing lots of knowledge but little understanding) and folks on this list (who make it their business to figure these things out and share the deductions). You have purchased some hardware from a reputable company who's installation instructions are pretty explicit. You've selected one of the architectures from a book that has been undisputed and in-print for over 10 years. Finally, you've participated on this list and have properly identified it as a source of well considered data and processes. Now you find yourself the victim of another "cook" in the kitchen who wants to dink with the recipe. Don't let this individual cause you to loose any sleep over his desire to insert his own originality or assuage his own lack of understanding at your expense. I'll suggest that he read the instructions and operating descriptions for the hardware you purchased. He should also review chapter 17 of the 'Connection. Finally, if his grasp of the underlying simple-ideas is incomplete, he's most welcome to join us here and lots of folks will gladly assist. For your benefit, know that the B&C regulators are specifically designed to work in concert and if set up per instructions, both alternators are never delivering power at the same time when wired per B&C instructions. The 20A regulator is set to 0.5 to 1.0 volts BELOW the main alternator. While both alternator switches may be ON, the aux alternator is in automatic standby until the main alternator shuts down and the aux alternator picks up the slack. At this time, circuits unique to the SB-1 alternator regulator will sense that the aux alternator has picked up ship's electrical loads and will also monitor the b-lead current demand from the aux alternator via the hall-sensor illustrated in . . . http://bandc.biz/14-SB1B.pdf If the loads are excessive (greater than 20A) the AUX ALTERNATOR LOADED light will flash. You reduce system loads until the light stops flashing and you're good to go for the duration of flight having held 100% of battery capacity in reserve. I appreciate your note on this topic . . . . it reminded me that I need to update Z-12 to show the hall-effect current sensor. I've updated the AutoCAD drawing at: http://www.aeroelectric.com/PPS/ACAD_Architecture_Dwgs/Z12L.dwg Appendix Z has been updated at: http://aeroelectric.com/articles/Rev11/AppZ_R11D.pdf The updated .pdf file is at: http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdf/Z12L.pdf Bob . . . ________________________________ Message 6 _____________________________________ Time: 01:40:01 PM PST US From: "Eric M. Jones" Subject: AeroElectric-List: Re: Low Temps (was gps display) --> AeroElectric-List message posted by: "Eric M. Jones" --> AeroElectric-List message posted by: "bob noffs" icubob@newnorth.net > Here is a good one. A friend was told by garmin that the cold could > permanently >damage the display on his gps. He bought a lowrance this summer and checked >into this with lowrance. After a lot of evasion and double talk it finally >came >out that their display could be damaged too. I think below about 0 deg. f. >How >do automobiles get away with it? Every airplane with a glass panal cant be >kept in a heated hanger. I see 25deg F below zero every year where I live. >Any >thoughts? Now here's a question I ponder every time I set fire to a wad of paper stuffed into my air cleaner trying to start my Lycoming.... A friend of mine pointed out that one of my designs used an LM311 which was not rated for military low temps. I called National Semi and they explained that ONLY the marking and testing was changed for the LM111 and LM211 parts (the mil spec parts). The parts were the same but they will charge an-arm-and-a-leg to test and mark them differently. The COTS initiative (Commercial Off The Shelf) pretty much eliminated the gold plated, ceramic sandwich, mil-spec parts. Hi-Rad space parts are a different story. So what changes at low temps? Crystals, Liquids--including liquid crystals... Lubricants, Plastics--including your acrylic windshield Bubela... Metal strength--including your propeller and crankshaft almost everything.... I am using NKK (Series TL) switches with a low temperature rating of -10 C (14 F)! Common guys... my ex-wife's heart is colder than that! Any ideas? Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 (508) 764-2072 "...Beans for supper tonight, six o'clock. Navy beans cooked in Oklahoma ham... Got to eat 'em with a spoon, raw onions and cornbread; nothing else...." --Will Rogers ________________________________ Message 7 _____________________________________ Time: 03:55:52 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re:gps install under AC 20 138A --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 11/25/2005 3:13:11 P.M. Central Standard Time, CardinalNSB@aol.com writes: I want to wire a ki202 cdi directly to a Garmin 300xl, and use either Elecro Mech switch/lights or some generic switches and lights. The Garmin manual says that lights and switches are required but does not specify the required part numbers (they do list their annunciators and the Mid-Continent part numbers as "Optional"). Good Evening Skip, Are you absolutely certain that you need any annunciators or switches at all? I have no experience with the 300XL, but I do have experience with many other GPSs including the Garmin 430. As long as the various functions are available within the Panel Control Unit, and the PCU is placed within the normal view of the pilot, there is no reason to have any external annunciators or switches. Why don't you take another look at just exactly what Garmin is telling you. I find it difficult to believe that the 300XL would need annunciators when the 430 does not. If you are going to place the PCU away from the primary panel, all that is required is that there be appropriate indicators repeating what is shown on the face of the PCU. I firmly believe you are making a problem where none exists! In what part of the country are you located? Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Air Park LL22 Downers Grove, IL 60516 630 985-8503 ________________________________ Message 8 _____________________________________ Time: 06:13:37 PM PST US From: G McNutt Subject: Re: AeroElectric-List: Re:gps install under AC 20 138A --> AeroElectric-List message posted by: G McNutt Hi Skip I used Electro Mech switch lights on my present SL-60 installation and will do same with the Garmin 300XL install in next aircraft. Question, does the KI 202 have an "analog resolver", in other words, will it talk to the 300XL to input a desired track or hold radial? Bob is correct that the 430 has all this neat stuff built right in however it is required with the 300XL. > >I want to wire a ki202 cdi directly to a Garmin 300xl, and use either >Elecro Mech switch/lights or some generic switches and lights. The Garmin manual >says that lights and switches are required. > > > ________________________________ Message 9 _____________________________________ Time: 07:04:04 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Re:gps install under AC 20 138A --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 11/25/2005 8:15:41 P.M. Central Standard Time, gmcnutt@shaw.ca writes: Bob is correct that the 430 has all this neat stuff built right in however it is required with the 300XL. Thank You George, That is good information to know. I had no idea the 300XL was that far behind times. My 1994 Trimble has everything needed within the PDU and I knew the 430 was OK. Goes to show I should not assume anything!. Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Air Park LL22 Downers Grove, IL 60516 630 985-8503 ________________________________ Message 10 ____________________________________ Time: 07:35:11 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RF Radiation --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 01:03 PM 11/24/2005 -0500, you wrote: >--> AeroElectric-List message posted by: > > Avionics-List message previously posted by: "Paul McAllister" > > ><having problems >with RF getting into systems and causing problems. > >The first area is headsets, I couldn't get my Lightspeeds to work properly. >Lightspeed >acknowledged that there can be problems and offered to modify the battery >box. That improved things, but from time to time I still have problems. > >The next on the list is my Navaid. Despite following Navaids suggestion of >disabling >the Navaid whenever the PTT is pressed I still have issues, if I transmit >for long enough it will still swing over to a 30 degree bank which is a real >pain if I am flying in IFR conditions. > >The latest trick is my intercom. Occasionally when I transmit I will get a >stuck >mike. I called the manufacturer and managed to speak to the design >engineer. >He acknowledged that is there is enough RF present then this could happen. >The company are currently working with me to resolve the issue. > >So..... does anyone have any ideas. I have a GX60 as my nav / com and the >antenna >(which is a Bob Archer) is buried in the tail. I have a single point ground >on the firewall.>> Your ground system is probably not a participant in the problems you're experiencing. Given that you have so many different systems being adversely affected, it appears that your cockpit space may be subject to an extra- ordinarily high RF field. First, I would make SURE that the radiation is coming from the normally working antenna as-installed. Can you put a temporary dummy load on the end of the coax before it goes into the vertical fin? If the problems go away, then it's normally radiated energy directly from the antenna. If the problem is still there, you have a coax joint open at a shield somewhere. When the inside of an airplane is this 'hot', it's a strong suggester of a compromised feed line. If the problems go away when the antenna is disconnected, try a belly mounted antenna with ground plane. This could reduce energy in the cockpit by 10db or more. The alternatives are to modify your affected systems to include the kind of filtering we generally design into vulnerable systems as a matter of course. I spent 7 days in Little Rock adding filters to a 1960's product that couldn't stand the 50-100 v/m interference present in some current production airplanes. 16 little capacitors were added to the backshell of the connector and potted. See: http://www.aeroelectric.com/Pictures/Filters/filter_caps.jpg http://www.aeroelectric.com/Pictures/Filters/potted_filter.jpg This is a crummy way to run an airplane accessories business. These SHOULD have been built into the device in the first place. Your task is similar. Deduce which wires are vulnerable (you need schematics of the accessories). Built test filters to see what works. See: http://www.aeroelectric.com/Pictures/Filters/breakout_filter_1.jpg http://www.aeroelectric.com/Pictures/Filters/breakout_filter_2.jpg These are filters required in the 2-30 MHz world. Since your problem is VHF (118-135 MHz) you might get by with ferrite beads. But even the ferrite bead doesn't work well if there is no downstream, shunt reactance (capacitor) to take advantage of the ferrite bead's series inductance. Then figure out how to get the necessary filtering either inside the victim accessory or right at the connector outside the accessory. In the OBAM aircraft world, you're ALLOWED to do anything you need to to to fix a problem. In the certified world, getting those caps installed was agonizingly difficult for non-technical reasons. Your best first step is to see if a different antenna style and location will work. Then go after the filters . . . Bob . . . ________________________________ Message 11 ____________________________________ Time: 08:03:26 PM PST US From: Carlos Sa Subject: AeroElectric-List: high brightness LEDs --> AeroElectric-List message posted by: Carlos Sa Can someone recommend some high brightness LEDs (and a source)? I ordered three or four types from the superbrightleds, but they don't seem that bright ( http://www.superbrightleds.com/index.html ) I'm looking for something like the ones being used in wingtip positioning lights - powerfull, but not in the Luxeon range ($)... Thanks in advance Carlos do not archive --------------------------------- ________________________________ Message 12 ____________________________________ Time: 08:36:00 PM PST US Subject: Re: AeroElectric-List: high brightness LEDs From: Scott --> AeroElectric-List message posted by: Scott You need to look at the Luxeons. They are the best brightness for the money, size and power I've found. If you are looking for an inexpensive wingtip light solution, try: http://www.eaa724.org/TechnicalStuff%20.html The only update from this article is that it might be wise to use a higher wattage resistor to help with heat dissipation. Scott Gettings On Friday, November 25, 2005, at 11:02 PM, Carlos Sa wrote: > --> AeroElectric-List message posted by: Carlos Sa > > > Can someone recommend some high brightness LEDs (and a source)? > > I ordered three or four types from the superbrightleds, but they > don't seem that bright ( http://www.superbrightleds.com/index.html ) > > I'm looking for something like the ones being used in wingtip > positioning lights - powerfull, but not in the Luxeon range ($)... > > Thanks in advance > > Carlos > do not archive > > > --------------------------------- > > ________________________________ Message 13 ____________________________________ Time: 10:13:23 PM PST US From: Joe Dubner Subject: AeroElectric-List: Cellphone-aviation Headset Interface --> AeroElectric-List message posted by: Joe Dubner Has anyone seen a schematic diagram of or taken apart a cell phone-aviation headset interface? Specifically, what are they composed of (active circuits, isolation resistors, transformers, etc.)? How do they work? Reference: http://store.yahoo.com/pilotsupport/2000s.html or: http://www.anrheadsets.com/CellUpgrade.asp Thanks, Joe Joe Dubner 523 Cedar Avenue Lewiston, ID 83501 cell: (208) 305-2688 ________________________________ Message 14 ____________________________________ Time: 10:13:55 PM PST US From: "Pete Howell" Subject: AeroElectric-List: P-mag Which Bus? --> AeroElectric-List message posted by: "Pete Howell" Hello, I am setting up my electric system for P-mags and in the Z-diagrams I see Bob has them set up on the main bus, but in other cases, the EI is set up on the battery bus. Understanding they can power themselves, which is the best Buss to power the P-mags? Thanks, Pete ________________________________ Message 15 ____________________________________ Time: 10:15:15 PM PST US From: Subject: AeroElectric-List: Re: Latching power relays? (Bob how about NO relays?) --> AeroElectric-List message posted by: Bob: You are right and good point, it does weigh .15 lbs more. You also point out the return on investment. I was originally told when they came out they where about $70 (2x's the price of a typical relay). They apparently cost more like $120. I understand you don't understand, but people just want the best, regardless of the nickels and dimes or logical. There are many other things people spend money on that cost 6 times more but do the same thing, but I agree with you here. It does not seem to pay for itself. To be honest since it is not lighter and cost significantly more I am re-evaluating if I will use it. Actually I may use no relays (see below). As far as power not every one has a large alternator and 25 amps of avionics. My VFR/Day/Night/IFR lite is less than 10 amps and nominal 7 amps. With a 40-amp alternator saving 8-10 watts about 3/4 th AMP, 0.70 amps could be considered significant. As far as heat I realize that is not a factor to anything but an illustration of the electrical energy being wasted and turned into heat. NOW THE QUESTION WHY HAVE A MASTER RELAY AT ALL? WHY HAVE A FIREWALL STARTER RELAY AT ALL? http://img377.imageshack.us/img377/1554/norelays9sp.jpg Run the positive battery cable direct to the starter's own solenoid, as in a car. For the master BUSS you could now use a little relay of say 40-80 amp capacity just for cockpit power. Since the starter current is not going thru a Master/ BAT relay, than all you need is a little relay. You could even use a solid state relay. With this wiring there are no large relays/contactors/solenoids except the one on the starter. This is like a car. That would save 1.6 lbs several large connections and about 0.80 amps. Also it would be less expensive. What do you think Bob? I know that people don't like the big wire going to the starter being HOT all the time but is there any real reason we need a MASTER relay with 500-700 AMP intermediate capacity. You could always keep the firewall starter relay so the big starter wire in not hot all the time.. Cheers George >Date: Nov 23, 2005 >From: "Robert L. Nuckolls, III" >Subject: Re: Latching power relays? >>How is the latching feature attractive to you? Where >> would you use it? >> >> Bob: >> You use it for a master. It is attractive because it uses less >>power than the inefficient old heavy . . . >These look like the Tyco/Kilovac EV200. [snip] spec'd at >0.95 pounds. An S702-1 (White-Rogers/Stancor) weighs 0.80 >pounds. >>metal cased relay that gets too hot to touch after a minute. >There are lots of things on the airplane that get too >hot to touch. If I never have a desire or need to touch them, >why is operating temperature a concern as long as it doesn't >significantly impact service life or load analysis? >>A "latching"(?) relay like suggested is a good alternative, >> >>http://www.bluesea.com/dept.asp?d_id=6619&l1=7958&l2=6 607 >> >>also as Eric suggested. I hate the idea of a little heat bomb >>wasting power. >"Wasting power" is a good thing to minimize. But let's carry > this to the ultimate exercise.. [snip] >Bob . . . --------------------------------- ________________________________ Message 16 ____________________________________ Time: 10:20:40 PM PST US From: Subject: AeroElectric-List: Re: Latching power relays? (Bob how about NO relays?) --> AeroElectric-List message posted by: Fixed the LINK below Bob: You are right and good point, it does weigh .15 lbs more. You also point out the return on investment. I was originally told when they came out they where about $70 (2x's the price of a typical relay). They apparently cost more like $120. I understand you don't understand, but people just want the best, regardless of the nickels and dimes or logical. There are many other things people spend money on that cost 6 times more but do the same thing, but I agree with you here. It does not seem to pay for itself. To be honest since it is not lighter and cost significantly more I am re-evaluating if I will use it. Actually I may use no relays (see below). As far as power not every one has a large alternator and 25 amps of avionics. My VFR/Day/Night/IFR lite is less than 10 amps and nominal 7 amps. With a 40-amp alternator saving 8-10 watts about 3/4 th AMP, 0.70 amps could be considered significant. As far as heat I realize that is not a factor to anything but an illustration of the electrical energy being wasted and turned into heat. NOW THE QUESTION WHY HAVE A MASTER RELAY AT ALL? WHY HAVE A FIREWALL STARTER RELAY AT ALL? http://img465.imageshack.us/img465/2636/norelays4zr.jpg Run the positive battery cable direct to the starter's own solenoid, as in a car. For the master BUSS you could now use a little relays of say 40-80 amp capacity just for cockpit power. Since the starter current is not going thru a Master/ BAT relay, than all you need is a little relay. You could even use a solid state relay. With this wiring there are no large relays/contactors/solenoids except the one on the starter. This is like a car. That would save 1.6 lbs several large connections and about 0.80 amps. Also it would be less expensive. What do you think Bob? I know that people don't like the big wire going to the starter being HOT all the time but is there any real reason we need a MASTER relay with 500-700 AMP intermediate capacity. You could always keep the firewall starter relay so the big starter wire in not hot all the time.. Cheers George >Date: Nov 23, 2005 >From: "Robert L. Nuckolls, III" >Subject: Re: Latching power relays? >>How is the latching feature attractive to you? Where >> would you use it? >> >> Bob: >> You use it for a master. It is attractive because it uses less >>power than the inefficient old heavy . . . >These look like the Tyco/Kilovac EV200. [snip] spec'd at >0.95 pounds. An S702-1 (White-Rogers/Stancor) weighs 0.80 >pounds. >>metal cased relay that gets too hot to touch after a minute. >There are lots of things on the airplane that get too >hot to touch. If I never have a desire or need to touch them, >why is operating temperature a concern as long as it doesn't >significantly impact service life or load analysis? >>A "latching"(?) relay like suggested is a good alternative, >> >>http://www.bluesea.com/dept.asp?d_id=6619&l1=7958&l2=6 607 >> >>also as Eric suggested. I hate the idea of a little heat bomb >>wasting power. >"Wasting power" is a good thing to minimize. But let's carry > this to the ultimate exercise.. [snip] >Bob . . . ---------------------------------