---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 08/14/03: 28 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:42 AM - Re: soldering iron question (Trampas) 2. 05:06 AM - Re: soldering iron question (KITFOXZ@aol.com) 3. 06:09 AM - The book I wish I'd written . . . (Eric M. Jones) 4. 07:06 AM - Re: The book I wish I'd written . . . (mailbox bob at mail.flyboybob.com) 5. 09:18 AM - Re: OV Module question for Bob (Robert L. Nuckolls, III) 6. 09:37 AM - Re: soldering iron question (drew.schumann@us.army.mil) 7. 09:40 AM - Re: The book I wish I'd written . . . (Robert L. Nuckolls, III) 8. 09:57 AM - Re: soldering iron question (Robert L. Nuckolls, III) 9. 10:14 AM - Re: Light Dimmer (Robert L. Nuckolls, III) 10. 10:28 AM - Re: soldering iron question (Denny) 11. 10:33 AM - Splicing a shielded cable (Charles Brame) 12. 11:07 AM - Re: Splicing a shielded cable (KITFOXZ@aol.com) 13. 12:48 PM - Re: OV Module question for Bob (Trampas) 14. 12:51 PM - Re: Splicing a shielded cable (Trampas) 15. 01:29 PM - Re: Splicing a shielded cable (Robert L. Nuckolls, III) 16. 01:32 PM - PA-20 generator question (Robert L. Nuckolls, III) 17. 02:22 PM - Re: OV Module question for Bob (Dave Grosvenor) 18. 03:13 PM - Analog to digital converter (David.vonLinsowe) 19. 03:35 PM - Re: Splicing a shielded cable (Charlie & Tupper England) 20. 05:15 PM - Re: slick mag tack sensor. (Robert L. Nuckolls, III) 21. 05:48 PM - Re: soldering iron question (drew.schumann@us.army.mil) 22. 06:16 PM - Re: Analog to digital converter (Robert L. Nuckolls, III) 23. 06:24 PM - Re: OV Module question for Bob (Robert L. Nuckolls, III) 24. 06:28 PM - Re: OV Module question for Bob (Robert L. Nuckolls, III) 25. 06:41 PM - New FAA AC On Amateur Built Aircraft (BAKEROCB@aol.com) 26. 06:58 PM - Re: New FAA AC On Amateur Built Aircraft (BobsV35B@aol.com) 27. 08:58 PM - Re: New FAA AC On Amateur Built Aircraft (John Rourke) 28. 09:11 PM - Re: New FAA AC On Amateur Built Aircraft (John Rourke) ________________________________ Message 1 _____________________________________ Time: 04:42:09 AM PST US From: "Trampas" Subject: RE: AeroElectric-List: soldering iron question --> AeroElectric-List message posted by: "Trampas" Drew, They make adjustable temperature modules for soldering irons. Most soldering irons are only 10-50W thus a standard 60W light dimmer should work. However if you want to do it your self look in an electronics book for SCR and Triacs, usually one of the standard examples is an AC light dimmer. http://www.discovercircuits.com/L/lite-dimmer.htm Trampas -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of drew.schumann@us.army.mil Subject: AeroElectric-List: soldering iron question --> AeroElectric-List message posted by: drew.schumann@us.army.mil In my prior post, I expressed the need for a fuse for my voltage converter, when I had an idea. I am using my voltage converter for various things, but one thing I'm using it for is to run a soldering iron. It is a 120V iron and I have 220V supply. Is there a solution that combines voltage conversion and variability of supply? My limited knowledge of electricity leads me to believe that because the iron is a pure resistor, it should be possible to construct a way to both convert voltage and vary the current to provide a way to vary the heat of the iron. Thanks a lot. Drew ________________________________ Message 2 _____________________________________ Time: 05:06:30 AM PST US From: KITFOXZ@aol.com Subject: Re: AeroElectric-List: soldering iron question --> AeroElectric-List message posted by: KITFOXZ@aol.com Hello Drew, Radio Shack makes a soldering iron temperature controller that is essentially a rheostat rated for 120 VAC and up to 150 watts. You could use your existing voltage converter to bring your 220 VAC line down to 120 VAC and then use this little jewel to control the heat at your soldering iron tip. It is Radio Shack Cat. No. 64-2054. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________ Message 3 _____________________________________ Time: 06:09:40 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: The book I wish I'd written . . . --> AeroElectric-List message posted by: "Eric M. Jones" I have Thomas L. Floyd's Digital Fundamentals and it is pretty good. It is easy to see he cares greatly about teaching the subject. Maybe even better--see Horowitz and Hill's The Art of Electronics. I want to strongly recommend Paul G. Hewitt's "Conceptual Physics" (and its many versions) as a good basis for an electronics education. Physics is fundamental to all science. This is one of those books you can't put down. Paul G. Hewitt is online and answers his emails. Bob--write your own electronics book. We know you have a lot of free time! Regards, ________________________________ Message 4 _____________________________________ Time: 07:06:58 AM PST US From: "mailbox bob at mail.flyboybob.com" Subject: RE: AeroElectric-List: The book I wish I'd written . . . --> AeroElectric-List message posted by: "mailbox bob at mail.flyboybob.com" Eric Jones Wrote << Bob--write your own electronics book. We know you have a lot of free time! >> Eric, You've forgotten the age old "buy vs. make" question. As long as we can buy good primers Bob doesn't need to write one. Lectric Bob's time is very well placed mentoring us on the aeroelictric-list. Books are great for general knowledge, but a real live consultant with real world experience is priceless! I greatly appreciate your contribution to the homebuilt aviation arena Bob. Anyway, you've already written a great book, The AeroElectric Connection. Regards, Bob Lee ______________________________ N52BL KR2 Suwanee, GA 30024 91% done only 51% to go! Phone/Fax: 770/844-7501 mailto:bob@flyboybob.com http://flyboybob.com Do not archive ________________________________ Message 5 _____________________________________ Time: 09:18:13 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: OV Module question for Bob --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:29 PM 8/13/2003 +0200, you wrote: >--> AeroElectric-List message posted by: "Dave Grosvenor" > >Bob, I did a couple of tests this evening before going ahead and shipping >this module over to you. I disconnected my starter motor. Now if I hit the >start button the starter relay pulls in and the OV breaker does not trip. >This I assume means that if there is an OV condition it is being caused by >the starter motor itself? Btw, wiring is as per fig 16 for the 912 and my >module is built from the current cct diagram on your web site using the two >transistors and zener. > >Is there anyone else on the list with a Rotax 912, wiring per fig.16 and an >OV module?? It's probably not a true OV condition that's tripping your module. There is a characteristic of silicon controlled rectifiers that makes the device itself sensitive to rapid changes (called dv/dt or change-in-voltage-with- respect-to-time) that can cause the SCR to trigger irrespective of the design intent of the circuit. We had a rash of problems with Bonanzas a couple of years ago that would trigger the OV protection when landing/taxi light switches were operated. In this case, it was the high-inrush current of lamps combined with the bounce characteristics of $high$ switches. The noise wasn't even close to a real OV event in terms of effects . . . it was just the extraordinarily fast rise time of the very low energy switching transient that irritated the SCR. For what is worth, the vast majority of my experience with nuisance tripping of the crowbar SCR has been with Rotax installations and/or EXP-Bus installations. In the EXP-Bus incidents, we added a diode across the coil of their avionics bus disconnect relay. In other cases, the pre-flight procedures were modified to simply not bring the alternator with ov protection on line until after the engine was running. Before you ship me your device, you might consider this alternative . . . It's likely that your project is properly assembled but simply installed in a situation that presses very close to the raggedy-edge of the circuit's capability to ignore certain noises. I'm considering a new design that substitutes a boss-hog MOS-FET for the SCR. Totally free of dv/dt trigger effects. Until a few years ago, FETs that could stand up to the 300A crowbar impulse were expensive. They're getting cheaper all the time. Bob . . . ________________________________ Message 6 _____________________________________ Time: 09:37:35 AM PST US From: drew.schumann@us.army.mil Subject: Re: AeroElectric-List: soldering iron question --> AeroElectric-List message posted by: drew.schumann@us.army.mil Thanks! Drew ----- Original Message ----- From: KITFOXZ@aol.com Subject: Re: AeroElectric-List: soldering iron question > --> AeroElectric-List message posted by: KITFOXZ@aol.com > > Hello Drew, > > Radio Shack makes a soldering iron temperature controller that is > essentially > a rheostat rated for 120 VAC and up to 150 watts. You could use > your > existing voltage converter to bring your 220 VAC line down to 120 > VAC and then use > this little jewel to control the heat at your soldering iron tip. > It is Radio > Shack Cat. No. 64-2054. > > John P. Marzluf > Columbus, Ohio > Kitfox Outback (out back in the garage) > > > _- > _- > _- > _- > ====================================================================== > > > > ________________________________ Message 7 _____________________________________ Time: 09:40:02 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: The book I wish I'd written . . . --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:09 AM 8/14/2003 -0400, you wrote: >--> AeroElectric-List message posted by: "Eric M. Jones" > >I have Thomas L. Floyd's Digital Fundamentals and it is pretty good. It is >easy to see he cares greatly about teaching the subject. Maybe even >better--see Horowitz and Hill's The Art of Electronics. >I want to strongly recommend Paul G. Hewitt's "Conceptual Physics" (and >its many versions) as a good basis for an electronics education. Physics >is fundamental to all science. This is one of those books you can't put >down. Paul G. Hewitt is online and answers his emails. I'll look this on up . . . >Bob--write your own electronics book. We know you have a lot of free time! Unless there's a compelling reason to write, I'd rather teach. Books have a distinct advantage for supplying portable, random access information to lots of folk with a minimum of organization . . . but when we find examples of really fine writing and illustrating, why bother? The only reason the 'Connection came into being is because I couldn't find a single publication in the bookstores at OSH that even began to say what needed to be said. Just put in an order for a couple of Floyd's for the nephews. Bob . . . ________________________________ Message 8 _____________________________________ Time: 09:57:24 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: soldering iron question --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:44 AM 8/14/2003 +0400, you wrote: >--> AeroElectric-List message posted by: drew.schumann@us.army.mil > >In my prior post, I expressed the need for a fuse for my voltage >converter, when I had an idea. I am using my voltage converter for >various things, but one thing I'm using it for is to run a soldering >iron. It is a 120V iron and I have 220V supply. Is there a solution that >combines voltage conversion and variability of supply? My limited >knowledge of electricity leads me to believe that because the iron is a >pure resistor, it should be possible to construct a way to both convert >voltage and vary the current to provide a way to vary the heat of the iron. > >Thanks a lot. Try a 1A, 600 volt diode in series with the iron. This will feed it with 1/2 the energy it would get if plugged directly into a 220v line and just what it needs to believe it's seeing a 120v source. I use diodes in the line cords of some my "killer" irons to put them into a lower temperature "standby" condition. Without the diode, they get too hot between tasks. Bob . . . ________________________________ Message 9 _____________________________________ Time: 10:14:17 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Light Dimmer --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:51 PM 8/13/2003 -0400, you wrote: >--> AeroElectric-List message posted by: John Schroeder > > > >> Been looking at some panel lighting pages from several of your wirebooks > >> and would like to try rolling my own dimmer for a confidence-builder. A > >> few questions about the diagram (SWB0298): > >> > > The LM338K is used on BOSS HOG dimmer (5A). > > Take a look at this data package for > > more details on building a smaller device > > with all the details on purchasing parts and > > assembling. > > I got almost everything I needed from the file you suggested, but would >like to know the brand, model and source for the 1000 ohm pots. Have >decided to build two of the smaller, 3 amp "Boss Hogs". Any 1000 ohm linear pot will work . . . pots of other sizes are fine too. Adjust values of other resistors proportionately like this: Pot Value R1 R2 1K 160 360 2.5K 390 910 5k 750 1.8K Radio Shack sells a 5K p/n 271-1714 http://support.radioshack.com/support_supplies/doc17/17639.htm Digiky has any value you want . . . nice miniatures are the RV6 series at http://dkc3.digikey.com/PDF/T032/0808.pdf > > > >> Would this be suitable for LED's? > > > > Maybe . . . depending on how many LEDs are in series, there > > is a network of resistor that can be incorporated to make > > the LED behave something like the incandescent lamp > > with respect to applied voltage. > I will be using one branch of one of the dimmers to control a string of >about 8 or 10 blue green LED's that will be mounted under the glare shield >for panel flood lights. What would the resistor network look like for that? > >Many thanks, probably one resistor array per lamp . . . colors other than red run at higher voltages than red. If you want these to track incandescent lamps on the same dimmer, you'll have to do some fiddling with resistor values. By adjusting resistors on the dimmer to set the control range from 4-12, you might be able to hook 10 leds into 5 series strings of 2. For this, the adjustment range of the dimmer would need to be 8-12 volts. You wouldn't need a BIG dimmer for just LEDS. A 0.5A dimmer would be fine and much smaller. It will take some work on the bench to work out the most useful combination of lights/resistors. Bob . . . ________________________________ Message 10 ____________________________________ Time: 10:28:04 AM PST US From: "Denny" Subject: RE: AeroElectric-List: soldering iron question --> AeroElectric-List message posted by: "Denny" This may be to simple of a solution but I think if you just place a 120 volt light bulb in (((SERIES)))) with the soldering iron will work and allow you to plug into your 240 volt source. You could vary the wattage by just using different wattage of light bulbs. Denny dennymortensen@cableone.net In my prior post, I expressed the need for a fuse for my voltage converter, when I had an idea. I am using my voltage converter for various things, but one thing I'm using it for is to run a soldering iron. It is a 120V iron and I have 220V supply. Is there a solution that combines voltage conversion and variability of supply? My limited knowledge of electricity leads me to believe that because the iron is a pure resistor, it should be possible to construct a way to both convert voltage and vary the current to provide a way to vary the heat of the iron. Thanks a lot. Drew ________________________________ Message 11 ____________________________________ Time: 10:33:46 AM PST US From: Charles Brame Subject: AeroElectric-List: Splicing a shielded cable --> AeroElectric-List message posted by: Charles Brame I bought a professionally wired harness for my intercom (SL-10M/S.) It has a shielded two wire conductor for an external speaker. Unfortunately, the cable is about four feet too short for my application. My fault, as I didn't specify a cable length when ordering the harness. I'm really not interested in cutting into the harness and opening the sealed multi-pin plug to replace the cable. Is there a simple and effective way to splice a shielded two wire cable and retain the shielding protection? Charlie Brame RV-6A N11CB San Antonio ________________________________ Message 12 ____________________________________ Time: 11:07:57 AM PST US From: KITFOXZ@aol.com Subject: Re: AeroElectric-List: Splicing a shielded cable --> AeroElectric-List message posted by: KITFOXZ@aol.com In a message dated 8/14/2003 1:34:25 PM Eastern Standard Time, charleyb@earthlink.net writes: Is there a simple and effective way to splice a shielded two wire cable and retain the shielding protection? Charlie Brame RV-6A N11CB San Antonio Hello Charlie, As long as this is not a coaxial cable try this method: Cut the cable in the area that you desire to locate your splice. From all ends of wire to be joined remove about 2 inches of the outer jacket (not the shield) and pull the two conductors through the side of the shielding right at the transition of bare shield and outer jacket. Twist the shields of each end into a "thicker third" stranded wire. Cut the ends of the two center conductor wires at odd lengths so that when joined the joints will not be on top of each other. This helps minimize bulk at the splice. Solder the wire ends side by side and don't forget to slip on a piece of heat shrink before soldering. Solder the shield ends together last. You will have a very short section of "unshielded" wire at each joint that will be very negligible in performance considerations. A larger piece of heat shrink over the whole area of each joint makes it neat and not a snag issue. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________ Message 13 ____________________________________ Time: 12:48:52 PM PST US From: "Trampas" Subject: RE: AeroElectric-List: OV Module question for Bob --> AeroElectric-List message posted by: "Trampas" Bob, Could you not just put an inductor inline with the sense pin. The inductor combined with a capacitor should make a nice second order filter which should snub the voltage spikes but not a true overload. I know that radio shack use to sale hum filters for going in line with car radio power line. If your radio shack still sales them it would be an easy thing to put in there to test with. Trampas -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: Re: AeroElectric-List: OV Module question for Bob --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:29 PM 8/13/2003 +0200, you wrote: >--> AeroElectric-List message posted by: "Dave Grosvenor" > >Bob, I did a couple of tests this evening before going ahead and shipping >this module over to you. I disconnected my starter motor. Now if I hit the >start button the starter relay pulls in and the OV breaker does not trip. >This I assume means that if there is an OV condition it is being caused by >the starter motor itself? Btw, wiring is as per fig 16 for the 912 and my >module is built from the current cct diagram on your web site using the two >transistors and zener. > >Is there anyone else on the list with a Rotax 912, wiring per fig.16 and an >OV module?? It's probably not a true OV condition that's tripping your module. There is a characteristic of silicon controlled rectifiers that makes the device itself sensitive to rapid changes (called dv/dt or change-in-voltage-with- respect-to-time) that can cause the SCR to trigger irrespective of the design intent of the circuit. We had a rash of problems with Bonanzas a couple of years ago that would trigger the OV protection when landing/taxi light switches were operated. In this case, it was the high-inrush current of lamps combined with the bounce characteristics of $high$ switches. The noise wasn't even close to a real OV event in terms of effects . . . it was just the extraordinarily fast rise time of the very low energy switching transient that irritated the SCR. For what is worth, the vast majority of my experience with nuisance tripping of the crowbar SCR has been with Rotax installations and/or EXP-Bus installations. In the EXP-Bus incidents, we added a diode across the coil of their avionics bus disconnect relay. In other cases, the pre-flight procedures were modified to simply not bring the alternator with ov protection on line until after the engine was running. Before you ship me your device, you might consider this alternative . . . It's likely that your project is properly assembled but simply installed in a situation that presses very close to the raggedy-edge of the circuit's capability to ignore certain noises. I'm considering a new design that substitutes a boss-hog MOS-FET for the SCR. Totally free of dv/dt trigger effects. Until a few years ago, FETs that could stand up to the 300A crowbar impulse were expensive. They're getting cheaper all the time. Bob . . . ________________________________ Message 14 ____________________________________ Time: 12:51:26 PM PST US From: "Trampas" Subject: RE: AeroElectric-List: Splicing a shielded cable --> AeroElectric-List message posted by: "Trampas" I some times take some aluminum foil and wrap around splice before shrinking the heat shrink. Trampas -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of KITFOXZ@aol.com Subject: Re: AeroElectric-List: Splicing a shielded cable --> AeroElectric-List message posted by: KITFOXZ@aol.com In a message dated 8/14/2003 1:34:25 PM Eastern Standard Time, charleyb@earthlink.net writes: Is there a simple and effective way to splice a shielded two wire cable and retain the shielding protection? Charlie Brame RV-6A N11CB San Antonio Hello Charlie, As long as this is not a coaxial cable try this method: Cut the cable in the area that you desire to locate your splice. From all ends of wire to be joined remove about 2 inches of the outer jacket (not the shield) and pull the two conductors through the side of the shielding right at the transition of bare shield and outer jacket. Twist the shields of each end into a "thicker third" stranded wire. Cut the ends of the two center conductor wires at odd lengths so that when joined the joints will not be on top of each other. This helps minimize bulk at the splice. Solder the wire ends side by side and don't forget to slip on a piece of heat shrink before soldering. Solder the shield ends together last. You will have a very short section of "unshielded" wire at each joint that will be very negligible in performance considerations. A larger piece of heat shrink over the whole area of each joint makes it neat and not a snag issue. John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________ Message 15 ____________________________________ Time: 01:29:53 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Splicing a shielded cable --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:30 PM 8/14/2003 -0500, you wrote: >--> AeroElectric-List message posted by: Charles Brame > > >I bought a professionally wired harness for my intercom (SL-10M/S.) It >has a shielded two wire conductor for an external speaker. >Unfortunately, the cable is about four feet too short for my >application. My fault, as I didn't specify a cable length when ordering >the harness. I'm really not interested in cutting into the harness and >opening the sealed multi-pin plug to replace the cable. > >Is there a simple and effective way to splice a shielded two wire cable >and retain the shielding protection? There's another reply that describes a perfectly acceptable method for splicing shielded wires . . . and I've done a comic book to illustrate the technique at: http://216.55.140.222/articles/Shielded_Wire_Splicing/ . . . . however, there's no good reason to shield speaker wires. Extending with ordinary twisted pair will be fine too. Bob. . . ________________________________ Message 16 ____________________________________ Time: 01:32:19 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: PA-20 generator question --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >Questions: I have Piper PA 20 with a Delco Remey 20amp Generator.It >recently died.I have a 35amp generator on the way and would like to fitt >it in place of the 20amp.The brackets and hardware will fitt.My main >concern is with any wire size changes and voltage regulator changes that >may be required.I would like to fitt a solid state voltage regulator.CDan >you help.Regards Paul. Current from the generator is controlled by the regulator. There is a fair chance that the 35A machine will work but no better than the 20A machine did. You'll have to upgrade power output wires -AND- the regulator if you want to take advantage of the higher output. If it were my airplane, I'd talk to B&C at 316.283.8000 about a field approval for L-40 alternator installation. Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________ Message 17 ____________________________________ Time: 02:22:16 PM PST US From: "Dave Grosvenor" Subject: Re: AeroElectric-List: OV Module question for Bob --> AeroElectric-List message posted by: "Dave Grosvenor" >For what is worth, the vast majority of my experience >with nuisance tripping of the crowbar SCR has been >with Rotax installations and/or EXP-Bus installations. >In the EXP-Bus incidents, we added a diode across the >coil of their avionics bus disconnect relay. In other >cases, the pre-flight procedures were modified to simply >not bring the alternator with ov protection on line until >after the engine was running. Before you ship me your >device, you might consider this alternative . . . Thanks for the help. I have ordered a S700-2-10 from B&C so that I can leave the alternator off for start up. At the moment my master is only an on-on type switch. Dave ________________________________ Message 18 ____________________________________ Time: 03:13:11 PM PST US Subject: AeroElectric-List: Analog to digital converter From: "David.vonLinsowe" --> AeroElectric-List message posted by: "David.vonLinsowe" Bob, It there such a device that will take the analog signal used with a ILS CDI and convert it to the digital output like a GPS outputs? The reason I ask is because Tru Track has setup their Digi Flight II autopilots to be all digital. They're looking to the future when everything will be digital. I would like to be able to use the autopilot with ILS, hence the need/want for the converter. I could upgrade to their unit that handles this, but the extra $3K isn't in my budget... :-) Thank you, and THANKS for sharing the years of electrical wisdom! Dave RV-6 ________________________________ Message 19 ____________________________________ Time: 03:35:19 PM PST US From: Charlie & Tupper England Subject: Re: AeroElectric-List: Splicing a shielded cable --> AeroElectric-List message posted by: Charlie & Tupper England Charles Brame wrote: >--> AeroElectric-List message posted by: Charles Brame > >I bought a professionally wired harness for my intercom (SL-10M/S.) It >has a shielded two wire conductor for an external speaker. >Unfortunately, the cable is about four feet too short for my >application. My fault, as I didn't specify a cable length when ordering >the harness. I'm really not interested in cutting into the harness and >opening the sealed multi-pin plug to replace the cable. > >Is there a simple and effective way to splice a shielded two wire cable >and retain the shielding protection? > >Charlie Brame >RV-6A N11CB >San Antonio > If it's the speaker output, the source & load impedances are so low that it would take a really wicked RF noise source to affect it even without a shield. Anything from simple soldered or crimped splices to your choice from dozens of different style connectors would work fine. If you want shielded, look at switchcraft.com. If you can get your hands on one of their print catalogs, it will be a lot easier to find a suitable connector. (OOPS, no AN numbers on their stuff. Is that a problem?) Charlie ________________________________ Message 20 ____________________________________ Time: 05:15:53 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: slick mag tack sensor. --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:28 AM 8/13/2003 -0400, you wrote: >--> AeroElectric-List message posted by: "Ron Raby" > >My enjine came with slick mags. One of the mags has a tack sensor lead >coming out of it. I have the JPI edm 900. They give you the sensor to go >into the slick mags. The only problem is that you have to remove a mag to >install the sensor. > >My question is does anyone know if the slick sensor will work with the EDM >system? Not a big deal to remove a mag. Just trying to save some time. there's more than one sensor technology for this task. It's quite possible that the sensor in the mag is not compatible with your tach . . . the 100% sure bet is to change it out. Bob . . . ________________________________ Message 21 ____________________________________ Time: 05:48:03 PM PST US From: drew.schumann@us.army.mil Subject: Re: AeroElectric-List: soldering iron question --> AeroElectric-List message posted by: drew.schumann@us.army.mil Thanks, Bob (and Denny) If figured that something like that would work, but seemed almost too simple. But, I guess a soldering iron is basically a pure resistor... Drew ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: soldering iron question > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 10:44 AM 8/14/2003 +0400, you wrote: > >--> AeroElectric-List message posted by: drew.schumann@us.army.mil > > > >In my prior post, I expressed the need for a fuse for my voltage > >converter, when I had an idea. I am using my voltage converter > for > >various things, but one thing I'm using it for is to run a > soldering > >iron. It is a 120V iron and I have 220V supply. Is there a > solution that > >combines voltage conversion and variability of supply? My > limited > >knowledge of electricity leads me to believe that because the > iron is a > >pure resistor, it should be possible to construct a way to both > convert > >voltage and vary the current to provide a way to vary the heat of > the iron. > > > >Thanks a lot. > > Try a 1A, 600 volt diode in series with the iron. This will > feed it with 1/2 the energy it would get if plugged directly into > a 220v line and just what it needs to believe it's seeing a > 120v source. > > I use diodes in the line cords of some my "killer" irons > to put them into a lower temperature "standby" condition. > Without the diode, they get too hot between tasks. > > Bob . . . > > > _- > _- > _- > _- > ====================================================================== > > > > ________________________________ Message 22 ____________________________________ Time: 06:16:51 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Analog to digital converter --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 06:04 PM 8/14/2003 -0400, you wrote: >--> AeroElectric-List message posted by: "David.vonLinsowe" > > >Bob, > >It there such a device that will take the analog signal used with a ILS >CDI and convert it to the digital output like a GPS outputs? > >The reason I ask is because Tru Track has setup their Digi Flight II >autopilots to be all digital. They're looking to the future when >everything will be digital. I would like to be able to use the >autopilot with ILS, hence the need/want for the converter. > >I could upgrade to their unit that handles this, but the extra $3K isn't >in my budget... :-) > >Thank you, >and THANKS for sharing the years of electrical wisdom! > >Dave >RV-6 It seems possible. There's a ton of jelly-bean processors that could be teamed with an analog-to-digital converter and programmed to convert the left-0-right analog into a digital word. The problem is that we need to know exactly what the autopilot expects in the way of a character string format. A study of section 4 of this document http://vancouver-webpages.com/peter/nmeafaq.txt describes various sentences or character strings that can be expected from various items of navigation equipment. A number of sentences have cross-track error . . . but I think most receivers output as a minimum, sentence RMB (which contains the following information: RMB - Recommended minimum navigation information (sent by nav. receiver when a destination waypoint is active) RMB,A,0.66,L,003,004,4917.24,N,12309.57,W,001.3,052.5,000.5,V*0B A Data status A = OK, V = warning 0.66,L Cross-track error (nautical miles, 9.9 max.), steer Left to correct (or R = right) 003 Origin waypoint ID 004 Destination waypoint ID 4917.24,N Destination waypoint latitude 49 deg. 17.24 min. N 12309.57,W Destination waypoint longitude 123 deg. 09.57 min. W 001.3 Range to destination, nautical miles 052.5 True bearing to destination 000.5 Velocity towards destination, knots V Arrival alarm A = arrived, V = not arrived *0B mandatory checksum Assuming the TruTrack uses this sentence to deduce steering actions, our task would be to "spoof" the autopilot into believing that data were coming from a digital device as opposed to a converter tied to an analog device. I would be easy to generate a string formatted as above wherein the 3rd and 4th values between commas was a digital representation of the analog steering data from your ILS indicator. We would need to know how smart the a/p is. Normally, as you get closer to the signal source in an analog (VOR, ILS, LOC) environment, a fixed DC level represents progressively smaller lateral displacement errors. This is why the VOR needle becomes very twitchy as you approach the the station. A digital nav aid will give cross-track error in constant distance of displacement from desired track irrespective of the range to waypoint. The mathematics an a/p has to accomplish to steer with cross-track error is much simpler than if it were steering on an analog (azimuth error). Autopilots designed to be accommodating of an analog system have to treat any displacement as having the same meaning . . . they end up being sloppy 5 miles out so that sensitivity is optimized at decision height (about half mile off the threshold). If we knew range to waypoint, then we could do the math to convert azimuth-error into cross-track error . . . but since your analog ILS receiver isn't privy to that information, we don't have enough data to present the a/p with a true representation of cross-track error. We would need to know if TruTrack uses range to waypoint as part of the control laws for approach to threshold. If he uses only cross-track error, then a simple converter is possible. It would take some experimentation to set conversion gain so that steering performance is optimized right at decision height just as the analog signal was getting "twitchy" . . . this would translate to the usual compromises 5 miles out with lower cost systems. If he uses range to waypoint, we'd just select some number for the "spoofer" to keep the autopilot thinking it's a half mile off the end of the runway. Short answer is that the hardware is easy and cheap. Telling the hardware how to do it's job is the challenging part and would probably need some cooperation on the part of Mr. Younkin. Bob . . . ________________________________ Message 23 ____________________________________ Time: 06:24:12 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: OV Module question for Bob --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 03:45 PM 8/14/2003 -0400, you wrote: >--> AeroElectric-List message posted by: "Trampas" > >Bob, > >Could you not just put an inductor inline with the sense pin. The >inductor combined with a capacitor should make a nice second order >filter which should snub the voltage spikes but not a true overload. > >I know that radio shack use to sale hum filters for going in line with >car radio power line. If your radio shack still sales them it would be >an easy thing to put in there to test with. > >Trampas Understand . . . but this inductor would have to be rated for carrying the crowbar-trip current. It can be as high as 300A (4 milliohms loop resistance) for 5 milliseconds or so. Adding the inductor's resistance to the trip path would lower the fault current but lengthen the trip time. Cutting fault current in half would increase trip time to 20 milliseconds. What you're thinking is certainly true but it's a little more complicated than just filtering a low power or signal line . . . the pathway in question has needs to open a breaker very quickly so that things don't overheat. Anything we do that slows things down has a ripple effect through other features of the design. In this case, half current for 4x the time would make his present SCR selection toast. Bob . . . ________________________________ Message 24 ____________________________________ Time: 06:28:07 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: OV Module question for Bob --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 11:03 PM 8/14/2003 +0200, you wrote: >--> AeroElectric-List message posted by: "Dave Grosvenor" > > >For what is worth, the vast majority of my experience > >with nuisance tripping of the crowbar SCR has been > >with Rotax installations and/or EXP-Bus installations. > >In the EXP-Bus incidents, we added a diode across the > >coil of their avionics bus disconnect relay. In other > >cases, the pre-flight procedures were modified to simply > >not bring the alternator with ov protection on line until > >after the engine was running. Before you ship me your > >device, you might consider this alternative . . . > > >Thanks for the help. I have ordered a S700-2-10 from B&C so that I can >leave the alternator off for start up. At the moment my master is only an >on-on type switch. Reasonable move. If we're lucky, there are no antagonists that will rear their ugly heads during normal ops and after the alternator is turned on. Bob . . . ________________________________ Message 25 ____________________________________ Time: 06:41:33 PM PST US From: BAKEROCB@aol.com Subject: AeroElectric-List: New FAA AC On Amateur Built Aircraft djgeldermann@cox.net, Pulsar-Builders@caseyk.org, aeroelectric-list@matronics.com, kisbuilders@angus.mystery.com, Drshufly@aol.com --> AeroElectric-List message posted by: BAKEROCB@aol.com 8/14/2003 Hello Fellow Builders, The FAA is in the process of updating AC 20-27E, Certification and Operation of Amateur-Built Aircraft, to version AC 20-27F. We have an opportunity to comment on the proposed AC. See the details at the following URL. <> I urge all interested in this subject to pass this information on and to review and contribute as appropriate to the proposed AC. Thanks. 'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? ________________________________ Message 26 ____________________________________ Time: 06:58:27 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: New FAA AC On Amateur Built Aircraft --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 8/14/03 8:42:07 PM Central Daylight Time, BAKEROCB@aol.com writes: > << > http://a257.g.akamaitech.net/7/257/2422/14mar20010800/edocket.access.gpo.gov > /2003/pdf/03-20409.pdf>> > > I urge all interested in this subject to pass this information on and to > review and contribute as appropriate to the proposed AC. > Good Evening OC, All I found at that address was the Federal Register notice. Is there an address where the proposed document can be accessed via the Internet? Happy Skies, Old Bob ________________________________ Message 27 ____________________________________ Time: 08:58:38 PM PST US From: John Rourke Drshufly@aol.com Subject: Re: AeroElectric-List: New FAA AC On Amateur Built Aircraft --> AeroElectric-List message posted by: John Rourke That URL is broken up, kinda hard to paste into a window, so anyone who has that problem, can use this: http://tinyurl.com/k31x -John R. do not archive BAKEROCB@aol.com wrote: >--> AeroElectric-List message posted by: BAKEROCB@aol.com > >8/14/2003 > >Hello Fellow Builders, The FAA is in the process of updating AC 20-27E, >Certification and Operation of Amateur-Built Aircraft, to version AC 20-27F. > >We have an opportunity to comment on the proposed AC. See the details at the >following URL. > ></2003/pdf/03-20409.pdf>> > >I urge all interested in this subject to pass this information on and to >review and contribute as appropriate to the proposed AC. > >Thanks. > >'OC' Baker, Builder of KIS TR-1 #116 4/14/97 - ?/?/? > > > > ________________________________ Message 28 ____________________________________ Time: 09:11:49 PM PST US From: John Rourke Subject: Re: AeroElectric-List: New FAA AC On Amateur Built Aircraft --> AeroElectric-List message posted by: John Rourke I just noticed that too - I think the FAA posting of the Draft Circular lags the news quite often... I believe the following URL will direct you to at as soon as it is posted on the website: http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgDAC.nsf/MainFrame?OpenFrameSet or the tiny URL: http://tinyurl.com/k337 I definitely want to know what's in this proposal! -John R. BobsV35B@aol.com wrote: >--> AeroElectric-List message posted by: BobsV35B@aol.com > >In a message dated 8/14/03 8:42:07 PM Central Daylight Time, BAKEROCB@aol.com >writes: > > > >><< >>http://a257.g.akamaitech.net/7/257/2422/14mar20010800/edocket.access.gpo.gov >>/2003/pdf/03-20409.pdf>> >> >>I urge all interested in this subject to pass this information on and to >>review and contribute as appropriate to the proposed AC. >> >> >> >Good Evening OC, > >All I found at that address was the Federal Register notice. Is there an >address where the proposed document can be accessed via the Internet? > >Happy Skies, > >Old Bob > > > >