---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 10/02/06: 38 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:14 AM - Re: battery cables & Relays - Now G's (FLYaDIVE@aol.com) 2. 05:14 AM - Re: battery cables & Relays - Now G's (FLYaDIVE@aol.com) 3. 05:25 AM - Re: Now G's (FLYaDIVE@aol.com) 4. 05:31 AM - Re: battery cables & Relays - Now G's (FLYaDIVE@aol.com) 5. 05:39 AM - Re: battery cables & Relays - Now G's (FLYaDIVE@aol.com) 6. 05:41 AM - Re: battery cables & Relays - Now G's (Bill Denton) 7. 05:46 AM - Alternator test lead (Bill Bradburry) 8. 06:09 AM - Re: battery cables & Relays - Now G's (FLYaDIVE@aol.com) 9. 06:16 AM - Re: battery cables & Relays - Now G's (FLYaDIVE@aol.com) 10. 06:18 AM - Re: Now G's (bob noffs) 11. 06:47 AM - Re: Now G's (Dan Brown) 12. 06:58 AM - Re: Brass bolt for firewall ground. (Eric M. Jones) 13. 07:15 AM - Re: Alternator test lead (Robert L. Nuckolls, III) 14. 07:20 AM - Re: battery cables & Relays - Now G's (Robert L. Nuckolls, III) 15. 07:23 AM - Re: Now G's (Robert L. Nuckolls, III) 16. 07:26 AM - Re: Re: Brass bolt for firewall ground. (Dave N6030X) 17. 07:47 AM - Strange Electrical failure in flight (Ron Patterson) 18. 08:10 AM - Re: battery cables & Relays 'G's" skunk stink (Eric M. Jones) 19. 08:33 AM - Re: Now G's (Bill Denton) 20. 08:34 AM - Connectors vs. Straight Wire (Dennis Johnson) 21. 09:02 AM - Re: Re: battery cables & Relays 'G's" skunk stink (Dave N6030X) 22. 09:15 AM - Glowing LED Warning Lights, Too Dark Now-LM317 (CardinalNSB@aol.com) 23. 09:33 AM - fat wire - skinny wires (Ernest Christley) 24. 10:11 AM - Re: Re: battery cables & Relays 'G's" skunk stink () 25. 10:58 AM - Re: Now G's (Gilles Thesee) 26. 01:39 PM - Garmin 396/496 Connections (Mark Chamberlain) 27. 02:09 PM - Re: Re: Mogas versus 100LL (Mostly Off Topic) (Hinde, Frank George (Corvallis)) 28. 02:09 PM - Re: Connectors vs. Straight Wire (Alan K. Adamson) 29. 03:14 PM - Re: Garmin 396/496 Connections (James Redmon) 30. 05:27 PM - Re: Connectors vs. Straight Wire (Dennis Johnson) 31. 06:05 PM - Re: Re: Connectors vs. Straight Wire (Alan K. Adamson) 32. 06:26 PM - Re: Connectors vs. Straight Wire (SteinAir, Inc.) 33. 06:57 PM - Re: Connectors vs. Straight Wire (Jim Baker) 34. 07:36 PM - Re: Glowing LED Warning Lights, Too Dark Now-LM317 (Ken) 35. 08:03 PM - Re: fat wire - skinny wires (Robert L. Nuckolls, III) 36. 09:07 PM - Re: Connectors vs. Straight Wire (Robert L. Nuckolls, III) 37. 09:08 PM - Re: Re: battery cables & Relays 'G's" skunk stink (Robert L. Nuckolls, III) 38. 09:14 PM - Re: Re: battery cables & Relays 'G's" skunk stink (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 05:14:00 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 10/1/06 11:58:27 AM Eastern Daylight Time, robert.mccallum2@sympatico.ca writes: > Barry; > > I don't know, but it's going to be pretty high as the deceleration distance > is extremely small, and you have to provide enough force to overcome > distorting the plastic past the detents. The weight of the cap is tiny, the > force required a few ounces, so the G's will be extreme. (now there's a > quantified term for you ) > > Bob McC =============================== EXCELLENT Bob, EXCELLENT! Now I know this is going to sound really crazy but ... It averaged 200 g's g's can be measure in either acceleration or deceleration and as the joke goes ... It is not the fall that kills you, it is the sudden stop. Barry "Chop'd Liver" ________________________________ Message 2 _____________________________________ Time: 05:14:00 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: FLYaDIVE@aol.com Hi Bill: - Bill's thoughts - Interesting test, but not really valid here... You "Bic pen" test measured essentially two things: Friction Sealing These are the two factor that determine the ease (or lack thereof) with which the cap can be seated on the pen. Gravity would have been a negligible factor in this type of test. [Barry] - Friction - YES Sealing - NO The test does not care if the cap seals, all it cares about is overcoming friction and moving the cap to is closed position. Other factors is the weight of the pen, weight of the cap and distance dropped, velocity of the objects before stopping and force absorption on the objects and impact surface. KE = 1/2 M x V2 But, take a guess on how many 'g's' were developed? - - - - - - - - - - - - - - - - - - - - - - Bill's thoughts - Assume that, if operated vertically, the solenoid can lift a 15 lb weight. Also assume that the movable contactor portion of the device weighs 1 lb. Obviously, it would take a gravitational force of greater than 15 g's to open the contactor. [Barry] - Good analogy, but what happened to the FRICTION, if it is part of the pen it is part of the solenoid. And there is also the constant opposite pull of the coil/solenoid for as long as power is applied. - - - - - - - - - - - - - - - - - - - - - - - Bill's thoughts - In an aircraft flying aerobatics, such factors as acceleration would also play a part in the equation... [Barry] - And when would acceleration be encountered? Especially at Max acceleration? NOT in straight and level flight! For the only acceleration then would be Rearward. Not pulling down on the plunger of the solenoid. (Vertically mounted relay) If you consider the acceleration {But it really isn't, it is the g force you are feeling} when you pull out of a dive ... That is a change in velocity which equates to g forces. When you pull out of a dive the plane slows down, it does not increase in speed. It is only the g force you feel that gives that impression. There is a difference between Velocity and Speed. ;-) Questions: If you point the nose of the plane down, say 3 degrees and the prop RPM is fixed will the plane increase in speed until it hits something? If you feel the g force (greater than 1 g) only during acceleration why can you feel the g force in a centrifuge at a constant speed? If you point the nose of the plane down, say 3 degrees and the prop RPM is fixed will there be an increase in g force until it hits something? Ain't physics grand? An Exlax a day keeps everybody away. Barry "Chop'd Liver" "Show them the first time, correct them the second time, kick them the third time." Yamashiada ________________________________ Message 3 _____________________________________ Time: 05:25:26 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: Now G's --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 10/1/06 12:37:36 PM Eastern Daylight Time, Gilles.Thesee@ac-grenoble.fr writes: > Those clear Bic pens are still around in my area. > What I'do is weigh the cap with a precision scale, then push the cap on > against a larger scale. And then do the math to get the gs... > > > Regards, > Gilles Thesee > Grenoble, France > http://contrails.free.fr =========================== Gilles: What you would be measuring there would be FORCE, not g's. It is the force to overcome the friction of the pen's closing mechanism. Don't use your hand in the test. It will adsorb some of the force in the opposite direction and give you a lower reading. You should hook up something like a screw / c-clamp fixture. Also, there is basically no acceleration in this test. But, you can work out the Mass of the entire pen use acceleration of 32 ft per second squared (sorry I do not recall the metric conversion) and apply it to the test. The number will not match the 200 g's I mentioned but it will be quite interesting, quite high. Barry "Chop'd Liver" ________________________________ Message 4 _____________________________________ Time: 05:31:16 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 10/1/06 12:58:53 PM Eastern Daylight Time, N6030X@DaveMorris.com writes: > Barry, I think when I worked in a government lab I must have had more > fun than you. We were shooting down missiles using an airborne laser > in a KC-135. You should see what a gigawatt pulsed CO2 laser does to > a BIC cap, or a chunk of asbestos concrete. > > :) > > Dave Morris ===================== Dave: You are a sick puppy ... But I like the way you think! (Punch line taken from a joke) I don't know who had more fun, but it sure was interesting. So, do we use LASER cannons today? Where can I get one? Are they small enough to mount on my car? Probably too expensive ... Just send me the schematic, I'll build one. Barry "Chop'd Liver" ________________________________ Message 5 _____________________________________ Time: 05:39:16 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 10/1/06 11:37:26 AM Eastern Daylight Time, khorton01@rogers.com writes: > How did you determine the relationship between the reading on > accelerometer when the pen landed on it and the acceleration that the > pen cap was subjected to? > > If the accelerometer wasn't mounted on the pen cap, I'm not really > sure what you were measuring. > > Kevin Horton > Ottawa, Canada Hi Kevin: By starting off in low increments of height and dropping the pen; at some height the cap would snap onto the barrel. Since all parts were falling as one unit the acceleration was the same for both the cap and the barrel. The accelerometer just read of the force of the impact in g's. Sort of like the egg drop experiment but in reverse. We did not want to preserve the egg ;-) We were making egg salad ;-). Barry "Chop'd Liver" ________________________________ Message 6 _____________________________________ Time: 05:41:58 AM PST US From: "Bill Denton" Subject: RE: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: "Bill Denton" Just for fun, a couple of points... I threw in "sealing" in the Bic pen discussion to deal with the air trapped in the cap. Given sufficient sealing, you would never be able to get the cap farther down than the compressibility of air would permit. I ignored friction in the solenoid as it would actually increase the force required to open the contacts. Interesting discussion... -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of FLYaDIVE@aol.com Sent: Monday, October 2, 2006 7:13 AM Subject: Re: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: FLYaDIVE@aol.com Hi Bill: - Bill's thoughts - Interesting test, but not really valid here... You "Bic pen" test measured essentially two things: Friction Sealing These are the two factor that determine the ease (or lack thereof) with which the cap can be seated on the pen. Gravity would have been a negligible factor in this type of test. [Barry] - Friction - YES Sealing - NO The test does not care if the cap seals, all it cares about is overcoming friction and moving the cap to is closed position. Other factors is the weight of the pen, weight of the cap and distance dropped, velocity of the objects before stopping and force absorption on the objects and impact surface. KE = 1/2 M x V2 But, take a guess on how many 'g's' were developed? - - - - - - - - - - - - - - - - - - - - - - Bill's thoughts - Assume that, if operated vertically, the solenoid can lift a 15 lb weight. Also assume that the movable contactor portion of the device weighs 1 lb. Obviously, it would take a gravitational force of greater than 15 g's to open the contactor. [Barry] - Good analogy, but what happened to the FRICTION, if it is part of the pen it is part of the solenoid. And there is also the constant opposite pull of the coil/solenoid for as long as power is applied. - - - - - - - - - - - - - - - - - - - - - - - Bill's thoughts - In an aircraft flying aerobatics, such factors as acceleration would also play a part in the equation... [Barry] - And when would acceleration be encountered? Especially at Max acceleration? NOT in straight and level flight! For the only acceleration then would be Rearward. Not pulling down on the plunger of the solenoid. (Vertically mounted relay) If you consider the acceleration {But it really isn't, it is the g force you are feeling} when you pull out of a dive ... That is a change in velocity which equates to g forces. When you pull out of a dive the plane slows down, it does not increase in speed. It is only the g force you feel that gives that impression. There is a difference between Velocity and Speed. ;-) Questions: If you point the nose of the plane down, say 3 degrees and the prop RPM is fixed will the plane increase in speed until it hits something? If you feel the g force (greater than 1 g) only during acceleration why can you feel the g force in a centrifuge at a constant speed? If you point the nose of the plane down, say 3 degrees and the prop RPM is fixed will there be an increase in g force until it hits something? Ain't physics grand? An Exlax a day keeps everybody away. Barry "Chop'd Liver" "Show them the first time, correct them the second time, kick them the third time." Yamashiada ________________________________ Message 7 _____________________________________ Time: 05:46:45 AM PST US From: "Bill Bradburry" Subject: AeroElectric-List: Alternator test lead --> AeroElectric-List message posted by: "Bill Bradburry" A couple of days ago, Bob referred to a method to attach a test lead to the alternator field wire to do easy troubleshooting of the alternator. A 1K ohm, 1/2 watt resistor was specified to isolate the test lead from the field. Would this same resistor work for a 28V system, or would a different resistor be required? Thanks, Bill Bradburry ________________________________ Message 8 _____________________________________ Time: 06:09:01 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 10/1/06 11:19:07 PM Eastern Daylight Time, Fiveonepw@aol.com writes: > Man, you sure can tell it's the weekend... ============= And a RAINY one here in the Mid Atlantic - NJ ________________________________ Message 9 _____________________________________ Time: 06:16:27 AM PST US From: FLYaDIVE@aol.com Subject: Re: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: FLYaDIVE@aol.com In a message dated 10/1/06 4:41:52 PM Eastern Daylight Time, nuckollsr@cox.net writes: > I suspect the > accelerometer was used as a timing device . . . I.e, > measurement of the force interval for stopping the > pen's fall, not as a direct measurement of acceleration. > > In any case, numbers in the hundreds of g's would not > surprise me. > > Bob . . . ======================= Righty O! Bob ... Averaged 200 g's The accelerometer read out in g's and the output was also shown on an O'scope. There was also other numbers, I don't recall, probably Newtons. Barry "Chop'd Liver" ________________________________ Message 10 ____________________________________ Time: 06:18:33 AM PST US From: "bob noffs" Subject: Re: AeroElectric-List: Now G's --> AeroElectric-List message posted by: "bob noffs" what am i missing? i dont see how acceleration enters in this equation? i was thinking the weight of the pen body divided into the force needed would give the g's. the 32 fps fps would be used to tell you how fast the pen was traveling when it hit the floor. bob noffs ----- Original Message ----- From: Sent: Monday, October 02, 2006 7:24 AM Subject: Re: AeroElectric-List: Now G's > --> AeroElectric-List message posted by: FLYaDIVE@aol.com > > In a message dated 10/1/06 12:37:36 PM Eastern Daylight Time, > Gilles.Thesee@ac-grenoble.fr writes: > >> Those clear Bic pens are still around in my area. >> What I'do is weigh the cap with a precision scale, then push the cap on >> against a larger scale. And then do the math to get the gs... >> >> >> Regards, >> Gilles Thesee >> Grenoble, France >> http://contrails.free.fr > =========================== > Gilles: > > What you would be measuring there would be FORCE, not g's. It is the > force > to overcome the friction of the pen's closing mechanism. Don't use your > hand > in the test. It will adsorb some of the force in the opposite direction > and > give you a lower reading. You should hook up something like a screw / > c-clamp > fixture. Also, there is basically no acceleration in this test. But, you > can > work out the Mass of the entire pen use acceleration of 32 ft per second > squared > (sorry I do not recall the metric conversion) and apply it to the test. > The > number will not match the 200 g's I mentioned but it will be quite > interesting, quite high. > > Barry > "Chop'd Liver" > > > ________________________________ Message 11 ____________________________________ Time: 06:47:23 AM PST US From: Dan Brown Subject: Re: AeroElectric-List: Now G's --> AeroElectric-List message posted by: Dan Brown -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 bob noffs wrote: > what am i missing? i dont see how acceleration enters in this equation? > i was thinking the weight of the pen body divided into the force needed > would give the g's. the 32 fps fps would be used to tell you how fast > the pen was traveling when it hit the floor. Gs are a measurement of acceleration, and you're correct that they can be determined from the weight of the pen body (or cap, depending on orientation) and the force required to seat the cap. The equation is F = m * a, where F is force, m is mass, and a is acceleration. If you want to solve for a, you just rearrange the equation to a = F / m. - -- Dan Brown, KE6MKS, dan@familybrown.org "Since all the world is but a story, it were well for thee to buy the more enduring story rather than the story that is less enduring." -- The Judgment of St. Colum Cille -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFIRkRyQGUivXxtkERAvq5AKDeGRnPMk2UAYiP4QAp8XI+NdPKNwCfWJdL bLJVFHzm1dqYohgrcErp9X0 =M3H8 -----END PGP SIGNATURE----- ________________________________ Message 12 ____________________________________ Time: 06:58:24 AM PST US Subject: AeroElectric-List: Re: Brass bolt for firewall ground. From: "Eric M. Jones" --> AeroElectric-List message posted by: "Eric M. Jones" Instead of using a brass or copper bolt, consider using a U-shaped bar of copper that is slipped in like a paper clip or bobby-pin. That way the fixturing and current conducting functions are separated. If this were on the edge of the firewall, no hole through the firewall might need to be made. "The man who carries a cat by the tail learns something that can be learned in no other way." - Mark Twain -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=65176#65176 ________________________________ Message 13 ____________________________________ Time: 07:15:03 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Alternator test lead --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:47 AM 10/2/2006 -0400, you wrote: >--> AeroElectric-List message posted by: "Bill Bradburry" > > >A couple of days ago, Bob referred to a method to attach a test lead to >the alternator field wire to do easy troubleshooting of the alternator. >A 1K ohm, 1/2 watt resistor was specified to isolate the test lead from >the field. Would this same resistor work for a 28V system, or would a >different resistor be required? ANY 1/2 watt resistor of 200 to 2000 ohms would do at any voltage. It's a protective measure to prevent a shorted test line from taking the alternator system down. You could put an in-line 1A fuse there too. The resistor is smaller and less 'lumpy' when inserted under heatshrink in the test line. With the resistor (or fuse) in place, a short downstream on the test wire won't upset the alternator system. Adding the resistor has a negligible effect on readings needed to diagnose the system. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 14 ____________________________________ Time: 07:20:15 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: battery cables & Relays - Now G's --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:38 AM 10/2/2006 -0400, you wrote: >--> AeroElectric-List message posted by: FLYaDIVE@aol.com > >In a message dated 10/1/06 11:37:26 AM Eastern Daylight Time, >khorton01@rogers.com writes: > > > How did you determine the relationship between the reading on > > accelerometer when the pen landed on it and the acceleration that the > > pen cap was subjected to? > > > > If the accelerometer wasn't mounted on the pen cap, I'm not really > > sure what you were measuring. > > > > Kevin Horton > > Ottawa, Canada > > >Hi Kevin: > >By starting off in low increments of height and dropping the pen; at some >height the cap would snap onto the barrel. Since all parts were falling >as one >unit the acceleration was the same for both the cap and the barrel. The >accelerometer just read of the force of the impact in g's. > >Sort of like the egg drop experiment but in reverse. We did not want to >preserve the egg ;-) Yeah, but if the accelerometer were stationary on the 'floor' then it's already at-rest when the pen hits it. The only data one might expect from the accelerometer is duration of the deceleration event, not its magnitude but I've not convinced myself that would work either. Accelerometers are sensitive to delta-v. If the critter is stuck to a relatively rigid surface like a concrete floor, whacking it with a falling pen would impart no motion. I think Gilles' suggestion for calculating the ratio of seating force to cap mass would yield the most meaningful result. Bob . . . ________________________________ Message 15 ____________________________________ Time: 07:23:58 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Now G's --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" Those clear Bic pens are still around in my area. What I'do is weigh the cap with a precision scale, then push the cap on against a larger scale. And then do the math to get the gs... Regards, Gilles Thesee Grenoble, France http://contrails.free.fr =========================== Gilles: What you would be measuring there would be FORCE, not g's. It is the force to overcome the friction of the pen's closing mechanism. Don't use your hand in the test. It will adsorb some of the force in the opposite direction and give you a lower reading. You should hook up something like a screw / c-clamp fixture. Also, there is basically no acceleration in this test. But, you can work out the Mass of the entire pen use acceleration of 32 ft per second squared (sorry I do not recall the metric conversion) and apply it to the test. The number will not match the 200 g's I mentioned but it will be quite interesting, quite high. Force is force is force . . . whether it's applied with the hand or any other device is not material to the measurement . . . except that to measure PEAK force as the cap moves over detent might me easier to observe if the force is applied in very small, smooth increments like with the clamp. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 16 ____________________________________ Time: 07:26:00 AM PST US From: Dave N6030X Subject: Re: AeroElectric-List: Re: Brass bolt for firewall ground. --> AeroElectric-List message posted by: Dave N6030X Eric, I can always identify your posts without even looking at the signature line, because they are so refreshingly outside the box. But I can't picture what you mean here. Can you explain further where the U is slipped into? Dave Morris At 08:57 AM 10/2/2006, you wrote: >--> AeroElectric-List message posted by: "Eric M. Jones" > >Instead of using a brass or copper bolt, consider using a U-shaped >bar of copper that is slipped in like a paper clip or bobby-pin. >That way the fixturing and current conducting functions are >separated. If this were on the edge of the firewall, no hole through >the firewall might need to be made. > > "The man who carries a cat by the tail learns something that can > be learned in no other way." - Mark Twain > >-------- >Eric M. Jones >www.PerihelionDesign.com >113 Brentwood Drive >Southbridge, MA 01550 >(508) 764-2072 >emjones@charter.net > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=65176#65176 > > ________________________________ Message 17 ____________________________________ Time: 07:47:04 AM PST US From: Ron Patterson Subject: AeroElectric-List: Strange Electrical failure in flight Just a note to let those of you who reponded to my question that I found the problem(s). I did, in fact, have a loose B lead and to some extent a loose main ground to the firewall. Once I tightened these connections up, no more problems. Thanks for all the help. Ron RV-4 N8ZD ________________________________ Message 18 ____________________________________ Time: 08:10:22 AM PST US Subject: AeroElectric-List: Re: battery cables & Relays 'G's" skunk stink From: "Eric M. Jones" --> AeroElectric-List message posted by: "Eric M. Jones" I think it is time for someone with a little authority to clear this up. My authority is so little that I have hidden it under one of the periods in this posting. A prize awaits the one who finds it. 1) Relay mounting. Type 70 Stancor Rodgers White Emerson Tyco. See: http://www.alliedelec.com/Images/Products/Datasheets/BM/STANCOR/Stancor_Industrial-Control_5760005.pdf So the manufacturer says, "mount plunger vertical, cap down". I checked into the engineering data on this part and of course the corporate conglomeratization has destroyed the engineering knowledge that built the part. The manufacturer PROMISED they'd get back to me.....It's not DO-160 bubela. And it's only 122 deg F max operating temp. Etc. etc. Use the Kilovac EV200 part if you can. (Yes, I am selling my Powerlink Jr. III now and I am MONTHS late.) 2) G-forces: [CAUTION-Head May Explode] Jacob Rabinow's Law (not that he called it that...). Gracefulness is "when the first, second, and third derivatives of the equation of motion monotonically and simultaneously go to zero." Which is to say--when the velocity, acceleration and impulse (the change in acceleration) smoothly and simultaneously go to zero. So many mysteries--a gyro will be ruined if placed on a workbench hard enough to be audible, but will do fine in an airplane doing aerobatics or combat. A pencil held horizontal and dropped 12 inches experiences G-forces that will destroy an airplane and kill a pilot. Curtis mercury-type elapsed-time meters were 12G-rated but failed if dropped on a workbench. Motion is composed of displacement, velocity, acceleration and impulse elements. The stiffness of a system determines which of these can be ignored in any practical application. Designers and engineers have the job of measuring some of these elements and constraining the system to prevent the others from becoming critical. This has other physical science analogues too. The exercise is left for the student. "Everything you've learned in school as "obvious" becomes less and less obvious as you begin to study the universe. For example, there are no solids in the universe. There's not even a suggestion of a solid. There are no absolute continuums. There are no surfaces. There are no straight lines." - R. Buckminster Fuller -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=65198#65198 ________________________________ Message 19 ____________________________________ Time: 08:33:35 AM PST US From: "Bill Denton" Subject: RE: AeroElectric-List: Now G's --> AeroElectric-List message posted by: "Bill Denton" "the cap moves over detent" JFTR: There is no detent, the cap is held in place by friction... -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Robert L. Nuckolls, III Sent: Monday, October 2, 2006 9:23 AM Subject: Re: AeroElectric-List: Now G's --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" Those clear Bic pens are still around in my area. What I'do is weigh the cap with a precision scale, then push the cap on against a larger scale. And then do the math to get the gs... Regards, Gilles Thesee Grenoble, France http://contrails.free.fr =========================== Gilles: What you would be measuring there would be FORCE, not g's. It is the force to overcome the friction of the pen's closing mechanism. Don't use your hand in the test. It will adsorb some of the force in the opposite direction and give you a lower reading. You should hook up something like a screw / c-clamp fixture. Also, there is basically no acceleration in this test. But, you can work out the Mass of the entire pen use acceleration of 32 ft per second squared (sorry I do not recall the metric conversion) and apply it to the test. The number will not match the 200 g's I mentioned but it will be quite interesting, quite high. Force is force is force . . . whether it's applied with the hand or any other device is not material to the measurement . . . except that to measure PEAK force as the cap moves over detent might me easier to observe if the force is applied in very small, smooth increments like with the clamp. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 20 ____________________________________ Time: 08:34:26 AM PST US From: "Dennis Johnson" Subject: AeroElectric-List: Connectors vs. Straight Wire Greetings, The entire instrument panel on my Lancair Legacy I'm building is attached to the airframe with only four bolts and is therefore relatively easy to remove in one large piece. That is, mechanically easy to remove, if it weren't for a bazillion wires connecting it to the airframe. On the other hand, the Legacy has a front hinged canopy and a removable glare shield, which provide reasonably good access to the rear of the instrument panel while it is in place. I can either run the wires from the airframe directly to the various components on the panel or I can insert D-Sub connectors between all the wires and the instrument panel. If I use connectors, it will make removing the instrument panel easier for repairs or upgrades. Running the wires directly to the panel, without connectors, will reduce the parts count but make future service more difficult. I'm torn between the two alternatives. My first thought was to add connectors to every wire in the expectation that I'll almost certainly want to remove the instrument panel at some point in the future for troubleshooting, repairs, or upgrades. Working on the panel while it's on my workbench is soooooo convenient. But there are tons of wires, many of them shielded, and running every single one of them through a connector is a big project. Considering that I have reasonable access to the rear of the panel with the canopy open and the glareshield removed, should I just plan to service the panel with it in place? Anybody who's "been there, done that" have any advice? Thanks, Dennis Johnson Lancair Legacy; painting done, still wiring the panel ________________________________ Message 21 ____________________________________ Time: 09:02:06 AM PST US From: Dave N6030X Subject: Re: AeroElectric-List: Re: battery cables & Relays 'G's" skunk stink --> AeroElectric-List message posted by: Dave N6030X Anybody have a centrifuge with accelerometer and want to conduct a little experiment? Dave Morris At 10:07 AM 10/2/2006, you wrote: >--> AeroElectric-List message posted by: "Eric M. Jones" > >I think it is time for someone with a little authority to clear this >up. My authority is so little that I have hidden it under one of the >periods in this posting. A prize awaits the one who finds it. > >1) Relay mounting. Type 70 Stancor Rodgers White Emerson Tyco. See: > >http://www.alliedelec.com/Images/Products/Datasheets/BM/STANCOR/Stancor_Industrial-Control_5760005.pdf > >So the manufacturer says, "mount plunger vertical, cap down". I >checked into the engineering data on this part and of course the >corporate conglomeratization has destroyed the engineering knowledge >that built the part. The manufacturer PROMISED they'd get back to >me.....It's not DO-160 bubela. And it's only 122 deg F max operating >temp. Etc. etc. Use the Kilovac EV200 part if you can. > >(Yes, I am selling my Powerlink Jr. III now and I am MONTHS late.) > >2) G-forces: [CAUTION-Head May Explode] Jacob Rabinow's Law (not >that he called it that...). Gracefulness is "when the first, second, >and third derivatives of the equation of motion monotonically and >simultaneously go to zero." Which is to say--when the velocity, >acceleration and impulse (the change in acceleration) smoothly and >simultaneously go to zero. > >So many mysteries--a gyro will be ruined if placed on a workbench >hard enough to be audible, but will do fine in an airplane doing >aerobatics or combat. A pencil held horizontal and dropped 12 inches >experiences G-forces that will destroy an airplane and kill a pilot. >Curtis mercury-type elapsed-time meters were 12G-rated but failed if >dropped on a workbench. > >Motion is composed of displacement, velocity, acceleration and >impulse elements. The stiffness of a system determines which of >these can be ignored in any practical application. Designers and >engineers have the job of measuring some of these elements and >constraining the system to prevent the others from becoming >critical. This has other physical science analogues too. > >The exercise is left for the student. > >"Everything you've learned in school as "obvious" becomes less and >less obvious as you begin to study the universe. For example, there >are no solids in the universe. There's not even a suggestion of a >solid. There are no absolute continuums. There are no surfaces. >There are no straight lines." > - R. Buckminster Fuller > >-------- >Eric M. Jones >www.PerihelionDesign.com >113 Brentwood Drive >Southbridge, MA 01550 >(508) 764-2072 >emjones@charter.net > > >Read this topic online here: > >http://forums.matronics.com/viewtopic.php?p=65198#65198 > > ________________________________ Message 22 ____________________________________ Time: 09:15:34 AM PST US From: CardinalNSB@aol.com Subject: AeroElectric-List: Glowing LED Warning Lights, Too Dark Now-LM317 MikeEasley wrote: My LED voltage warning lights are now too dark to see in daylight after adding the resistors in the drawing. Smaller resistors? I have been "playing" with leds on a breadboard, controlling them with a LM317. The LM317 supplies constant voltage, determined by a resistance to (the control leg, I don't know the real term). I have used a rheostat and been able to control multiple or single leds, from very bright to very dim/off. I am planning to make an annunciator for a 300xl gps, which always has 2 leds on, sometimes 3, sometimes 4. I have the LM317 between the battery positive and the leds, the leds taking power from the LM317 with their other leg grounded. The leds are in parallel. A value to me of the LM317 is to be able to maintain constant brightness of multiple leds (I plan to use all the same white leds with colored lenses for colors). The LM317 is from Radio Shack and I have only used the circuit on the back of the box-LM317, a resistor, and a rheostat, 3 parts. Could I wire a backup with a zener diode for a constant brightness? However, I have been told this LM317 won't work, that I need Pulse Width Modulation. I'm not sure why, the LM317 seems to do what I want at least on my desk at home, is cheap and low parts count. I would appreciate any reasons this would not be a proper way to control multiple identical leds-rf production? Skip Simpson ________________________________ Message 23 ____________________________________ Time: 09:33:53 AM PST US From: Ernest Christley Subject: AeroElectric-List: fat wire - skinny wires --> AeroElectric-List message posted by: Ernest Christley I seem to remember there being some rationale for not running fat wires in the same bundle with skinny wires, but I can find a specific reference to it in the "Aero-electric Connenction". Does such a rationale exist, or am I suffering from delusions of toxic aircraft chemical fumes? My #2 battery cable currently follows a rather tortuous path from the tailpost to the front of the plane, and I could be a lot simple (and a few pounds lighter), if it just ran down the side with a bunch of wires that include microphone/headphone leads, taillight, tail strobe, fuel pump powere, and a linear actuator control leads. -- ,|"|"|, Ernest Christley | ----===<{{(oQo)}}>===---- Dyke Delta Builder | o| d |o http://ernest.isa-geek.org | ________________________________ Message 24 ____________________________________ Time: 10:11:07 AM PST US Subject: Re: AeroElectric-List: Re: battery cables & Relays 'G's" skunk stink From: --> AeroElectric-List message posted by: Hello Eric You wrote: "So the manufacturer says, "mount plunger vertical, cap down" I have never taken apart or looked very close at the relay that is being talked about. I can tell you that on old Savin 220 copiers had a lamp relay they called a K-5. It had a plunger that rode inside a brown phenolic guide. It was mounted horizontal. After some time, the phenolic would wear, and make a quite useful plunger movement limiting pocket in the phenolic. It was useful in demonstrating to customers just how a high resistance connection could cause so much smoke and not trip the main circuit breaker, that is until flames were a happening and the insulation complete gave way and then tripped. It was the contacts wearing out, and the pocket limiting motion. On machines under contract I modified to a vertical plunger. Could happen in some cases 10,000 copies. It was a 115V AC 15 amp relay, the plunger was perhaps 3/16" or 1/4" in diameter. all that was needed was a .005" pocket. Ron Parigoris ________________________________ Message 25 ____________________________________ Time: 10:58:52 AM PST US From: Gilles Thesee Subject: Re: AeroElectric-List: Now G's --> AeroElectric-List message posted by: Gilles Thesee Hi all, > > JFTR: There is no detent, the cap is held in place by friction... > That's right, the clear Bic has no detent. For those interested, I've just done the Bic experiment. I'll take some pictures tomorrow, and craft a preliminary report on this major contribution to the advancement of Bic science. Regards, Gilles Thesee Grenoble, France http://contrails.free.fr ________________________________ Message 26 ____________________________________ Time: 01:39:37 PM PST US From: "Mark Chamberlain" Subject: AeroElectric-List: Garmin 396/496 Connections --> AeroElectric-List message posted by: "Mark Chamberlain" Hi folks, I just purchased a bare wire data lead for the Garmin 396/496. It has several wires coming out of it, there are a couple labeled: Voice (-), Voice (+), alarm etc. Unfortunately there are no instructions as to where they are supposed to go. For example is the "alarm" wire for an audio alarm and therefore needs to be routed to a unswitched audio hook up? Or should it go to a light on the panel? What are the "Voice" wires for? Some sort of voice audio warnings or voice in to the unit? Not sure what they would be for as the audio out of the unit is stereo and therefor requires 3 wires, not just 2. If any of you guys have used this data cable to hard wire you GPS could you throw some light on this? Thanks, Mark - RV-7 finishing up last 5% ________________________________ Message 27 ____________________________________ Time: 02:09:07 PM PST US Subject: RE: AeroElectric-List: Re: Mogas versus 100LL (Mostly Off Topic) From: "Hinde, Frank George (Corvallis)" Don Rivera told me directly by email. Frank ________________________________ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of 6440 Auto Parts Sent: Thursday, September 28, 2006 3:46 PM Subject: Re: AeroElectric-List: Re: Mogas versus 100LL (Mostly Off Topic) Frank did you go to an AFS seminar ? If so was it worth it ? If not where did you get the info that their system will run 100% ethanol ? I have'nt found much real info on their website. Randy ----- Original Message ----- From: Hinde, Frank George (Corvallis) To: aeroelectric-list@matronics.com Sent: Thursday, September 28, 2006 4:48 PM Subject: RE: AeroElectric-List: Re: Mogas versus 100LL (Mostly Off Topic) When i spoke to Superior they stated Vapour lock as the issue with ethanol mix...But when i asked if they really meant vapour lock or simply boiling of fuel in the injector lines ...Which is not vapour lock I did not get an answer. Secondly with my Airflow Performance system it can run on 100% ethanol if you so desire. I have high regard for Superior, don't get me wrong but there are MANY OWTs out there that one is forced to question. ECI states lead being a lubricant for valve seats as Gospel for example...I don't buy it because, 1 it sounds ridiculous and 2 there is more and more evidence to the contrary. Now in order to preserve the warranty (if there really is one) ECI demand that you use 100LL duting break in...OK for sure i will only start feeding in mogas after 25 hours or so...Not worth the risk. Soo..if you have a properly designed fuel system (my pumps are in the wingroots) I'm having a hard time understanding the objection to ethanol mixes...Apart from the fact we're getting short changed (lower grade fuel)to support our totally excessive farm production of course...:) Now it maybe the injector line boiling is so bad it s difficult to get the engine to run smooth...Definatly a possibility. I will phone Todd Peterson next week who has offered to fill me in (metaphorically speaking) on why ehtanol in mogas is a really bad thing....Not saying that he will be incorrect, just I don't understand why not at the moment. Frank Another 5 hours and i start filling gas cans...Non ethanol...for now..:) ________________________________ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jerry2DT@aol.com Sent: Thursday, September 28, 2006 2:05 PM To: aeroelectric-list@matronics.com Subject: AeroElectric-List: Re: Mogas versus 100LL (Mostly Off Topic) Excellent article on Ethanol in current Consumer Reports. A couple things for sure are that Ethanol has 30% less BTU's than Gasoline 125k btu/gal vs. 84.4), thereby translating to 32% less mileage per gal. Ethanol is cleaner, which I guess is why it is mandated in some parts. I track my car gas mileage very closely and get 8% less mpg when using a mix. The math doesn't come out quite right with the btu's, but it is a fact, at least for my car. It is alleged that Ethanol rots some seals, gaskets. My 1996 Honda motorcycle specifically disallows it's use. There is no way I'll ever use a mix of gas/ethanol in my aircraft. Superior also bans Ethanol btw, although encourages use of premium mogas for their XP360's... FWIW, .02, etc. Jerry Cochran From: "Hinde, Frank George (Corvallis)" --> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" Indeed yes are...but do you measure the RVP before you use it?...Even if the RVP is a little high you can ajust your flying to suit. As a bit of an aside I probably wouldn't store mogas for 6 months before using it. More of a question is wat if ethanol appears in the mix...i have an invite to phone Todd at Peterson for the low down on why not to use Ethanol...I'm not convinced on that one...at least not yet. More to come matronics.com/Navigator?AeroElectric-List matronics.com/Navigator?AeroElectric-List ________________________________ Message 28 ____________________________________ Time: 02:09:08 PM PST US From: "Alan K. Adamson" Subject: RE: AeroElectric-List: Connectors vs. Straight Wire Dennis. I might be late with this comment.... But Cannon Plugs, Cannon Plugs, Cannon Plugs..... Did I say Cannon Plugs? You can get them in various densities. I'd try to keep it to 3 or 4 and group things together in logical sense. I know you can get them Lancair, or there are probably other sources as well. I've not gone there yet, but when I do, it will be Deutch connectors and Cannon plugs you can be assured. Also, heat-shrink labelers are pretty cheap and are available on ebay to help keep things grouped and sorted and labeled. Alan _____ From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dennis Johnson Sent: Monday, October 02, 2006 11:34 AM Subject: AeroElectric-List: Connectors vs. Straight Wire Greetings, The entire instrument panel on my Lancair Legacy I'm building is attached to the airframe with only four bolts and is therefore relatively easy to remove in one large piece. That is, mechanically easy to remove, if it weren't for a bazillion wires connecting it to the airframe. On the other hand, the Legacy has a front hinged canopy and a removable glare shield, which provide reasonably good access to the rear of the instrument panel while it is in place. I can either run the wires from the airframe directly to the various components on the panel or I can insert D-Sub connectors between all the wires and the instrument panel. If I use connectors, it will make removing the instrument panel easier for repairs or upgrades. Running the wires directly to the panel, without connectors, will reduce the parts count but make future service more difficult. I'm torn between the two alternatives. My first thought was to add connectors to every wire in the expectation that I'll almost certainly want to remove the instrument panel at some point in the future for troubleshooting, repairs, or upgrades. Working on the panel while it's on my workbench is soooooo convenient. But there are tons of wires, many of them shielded, and running every single one of them through a connector is a big project. Considering that I have reasonable access to the rear of the panel with the canopy open and the glareshield removed, should I just plan to service the panel with it in place? Anybody who's "been there, done that" have any advice? Thanks, Dennis Johnson Lancair Legacy; painting done, still wiring the panel ________________________________ Message 29 ____________________________________ Time: 03:14:49 PM PST US From: "James Redmon" Subject: Re: AeroElectric-List: Garmin 396/496 Connections --> AeroElectric-List message posted by: "James Redmon" Actually, you do have instructions - they are in the GPS unit's Pilot's Guide toward the back. Even has a diagram to show you how it all hooks up. The "Voice" lines are external speaker lines for the auto-navigation speak output - "turn right in 100 feet", etc. Has nothing to do with "aviation" related features as all of those warnings and XM music all come out the audio plug. Hope that helps. James Redmon Berkut #013 N97TX http://www.berkut13.com ----- Original Message ----- From: "Mark Chamberlain" Sent: Monday, October 02, 2006 3:37 PM Subject: AeroElectric-List: Garmin 396/496 Connections > --> AeroElectric-List message posted by: "Mark Chamberlain" > > > Hi folks, > > I just purchased a bare wire data lead for the Garmin 396/496. It has > several wires coming out of it, there are a couple labeled: Voice (-), > Voice (+), alarm etc. Unfortunately there are no instructions as to where > they are supposed to go. For example is the "alarm" wire for an audio > alarm and therefore needs to be routed to a unswitched audio hook up? Or > should it go to a light on the panel? What are the "Voice" wires for? Some > sort of voice audio warnings or voice in to the unit? Not sure what they > would be for as the audio out of the unit is stereo and therefor requires > 3 wires, not just 2. > > If any of you guys have used this data cable to hard wire you GPS could > you throw some light on this? > > Thanks, > > Mark - RV-7 finishing up last 5% ________________________________ Message 30 ____________________________________ Time: 05:27:44 PM PST US Subject: AeroElectric-List: Re: Connectors vs. Straight Wire From: "Dennis Johnson" --> AeroElectric-List message posted by: "Dennis Johnson" Hi Alan, Thanks for the reply to my question about connectors to allow removing the instrument panel. You suggested Cannon plugs. It seems to me that Cannon plugs are more expensive and less convenient to install than D-Sub connectors. I hope there's not a fundamental problem with D-Subs because nearly every electronic component I installed came with D-Subs on the back. Best, Dennis Read this topic online here: http://forums.matronics.com/viewtopic.php?p=65345#65345 ________________________________ Message 31 ____________________________________ Time: 06:05:54 PM PST US From: "Alan K. Adamson" Subject: RE: AeroElectric-List: Re: Connectors vs. Straight Wire --> AeroElectric-List message posted by: "Alan K. Adamson" Oh, I think they would work ok... Except, I had one bad experience. I had a monitor with a 15pin D-Sub on it. It worked for a couple of years and then all of a sudden it started to flake out... I found that the "tension" on the female pins started to fail. I would have to "cock" the connector in order that the colors on the monitor appeared correct. Finally, it just wouldn't take any jiggling to get the colors right and I had to buy a new monitor. YMMV, but there are lots of kinds of Cannon plugs, and it's a one time investment. For something like interconnects that have to survive in "hostile" environments, its just my preference, but I'll use cannon plugs. Good luck btw, can't wait to see yours sometime :)... Alan -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dennis Johnson Sent: Monday, October 02, 2006 8:26 PM Subject: AeroElectric-List: Re: Connectors vs. Straight Wire --> AeroElectric-List message posted by: "Dennis Johnson" --> Hi Alan, Thanks for the reply to my question about connectors to allow removing the instrument panel. You suggested Cannon plugs. It seems to me that Cannon plugs are more expensive and less convenient to install than D-Sub connectors. I hope there's not a fundamental problem with D-Subs because nearly every electronic component I installed came with D-Subs on the back. Best, Dennis Read this topic online here: http://forums.matronics.com/viewtopic.php?p=65345#65345 ________________________________ Message 32 ____________________________________ Time: 06:26:26 PM PST US From: "SteinAir, Inc." Subject: RE: AeroElectric-List: Connectors vs. Straight Wire My comment will probably be a little different from the typical..but, I'd push you to do as much straight wiring as possible. On my 1st plane I did the Canon Plug thing all over the place.....have you ever tried to troubleshoot an electrical gremlin through a bunch of canon plugs or D-Subs? It's a pain in the rear. Once you add hundreds of pins, that's hundreds of new joints that are potential future problem areas. Next, why do you really need them? Sure, it sounds like a great idea, but really....how many times do you actually take a panel in and out of plane? As far as individual components, it only takes a couple screws to drop out any of the EFIS's out there, radios slide out of trays, etc..., so you don't get much advantage there. Next, even if you wanted you shouldn't run everything through canon plugs. Audio Wires specifically can get really touchy running them through connectors...all the headset, mic, aux leads are/should be shielded and breaking that shield just creates another area for noise and more gremlins to move in. You can't shouldn't split EGT/CHT wires, nor some other sensor wires along with the heavy wires. Basically, it looks good at airshows and in magazines, but the truth of the matter is it's almost impossible to get by NOT hooking some things directly to your panel anyway and then there you are with a bunch of nice looking canon plugs, then you Still have to remove things from the panel anyway....point is no matter what your intentions you'll still probably have a bunch of stuff hooked directly to the panel anyway (pitot tubing, static tubing, maybe some antennas, fat battery wires, 02 lines if you have them, "P" leads which shouldn't be broke, air vents lines, push/pull cables, so on and so forth). I guess I'm trying to say that anytime you added un-needed connections to a particular system you are just asking for longer term troubles and an overall reduction in reliability. Keep It Simple! Most of today's major components come out of the panels so easily that I can't see a huge benefit of just adding connectors in case someday you might want to yank the whole panel out? The point is you should wire and build your airplane for the 99th percentile of it's functionality and reliability, not the 1% "whatifs". I don't know if this all makes sense or not, but if it were me (and it is dozens of times we discuss panels with customers), I really try to put function ahead of form and convince people to do what makes sense from a functional, reliable and simplicity standpoint. You can't beat it! Cheers, Stein. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Dennis Johnson Sent: Monday, October 02, 2006 10:34 AM To: aeroelectric-list@matronics.com Subject: AeroElectric-List: Connectors vs. Straight Wire Greetings, The entire instrument panel on my Lancair Legacy I'm building is attached to the airframe with only four bolts and is therefore relatively easy to remove in one large piece. That is, mechanically easy to remove, if it weren't for a bazillion wires connecting it to the airframe. On the other hand, the Legacy has a front hinged canopy and a removable glare shield, which provide reasonably good access to the rear of the instrument panel while it is in place. I can either run the wires from the airframe directly to the various components on the panel or I can insert D-Sub connectors between all the wires and the instrument panel. If I use connectors, it will make removing the instrument panel easier for repairs or upgrades. Running the wires directly to the panel, without connectors, will reduce the parts count but make future service more difficult. I'm torn between the two alternatives. My first thought was to add connectors to every wire in the expectation that I'll almost certainly want to remove the instrument panel at some point in the future for troubleshooting, repairs, or upgrades. Working on the panel while it's on my workbench is soooooo convenient. But there are tons of wires, many of them shielded, and running every single one of them through a connector is a big project. Considering that I have reasonable access to the rear of the panel with the canopy open and the glareshield removed, should I just plan to service the panel with it in place? Anybody who's "been there, done that" have any advice? Thanks, Dennis Johnson Lancair Legacy; painting done, still wiring the panel ________________________________ Message 33 ____________________________________ Time: 06:57:45 PM PST US From: "Jim Baker" Subject: RE: AeroElectric-List: Connectors vs. Straight Wire X-mailer: Pegasus Mail for Windows (4.41) --> AeroElectric-List message posted by: "Jim Baker" > I guess I'm trying to say that anytime you added un-needed connections to a particular system > you are just asking for longer term troubles and an overall reduction in reliability. ____________________________________________ Spot on! Besides, you'll have a lot of the panel terminated in connectors of one sort or another anyway....how hard to remove those..... Tho I kinda wish the D-sub folks would go back to the old Centronics wire bail form of shell attachment. No trying to get the screw driver on the screw head in a spot you can't easily see. Jim Baker 580.788.2779 Elmore City, OK ________________________________ Message 34 ____________________________________ Time: 07:36:39 PM PST US From: Ken Subject: Re: AeroElectric-List: Glowing LED Warning Lights, Too Dark Now-LM317 --> AeroElectric-List message posted by: Ken The brightness of an LED is proportional to the current going through it. You need a resistor in series with each LED to limit the max current and max brightness. Connecting all those resistors to the output of your LM317 should do what you want. When you dim (lower the voltage ouput of the LED) there will be less voltage drop through each resistor and the brightness will reduce. That brightness should not change regardless of how many LED's are on because each LED has its own resistor. I think that is your answer - a separate resistor for each LED. Of course with this description, it is assumed that individual LED's are turned on by connecting its negative lead to ground. Ken L. CardinalNSB@aol.com wrote: > MikeEasley wrote: > > My LED voltage warning lights are now too dark to see in daylight > after > adding the resistors in the drawing. > > Smaller resistors? > > I have been "playing" with leds on a breadboard, controlling them with > a LM317. The LM317 supplies constant voltage, determined by a > resistance to (the control leg, I don't know the real term). I have > used a rheostat and been able to control multiple or single leds, from > very bright to very dim/off. I am planning to make an annunciator for > a 300xl gps, which always has 2 leds on, sometimes 3, sometimes 4. I > have the LM317 between the battery positive and the leds, the leds > taking power from the LM317 with their other leg grounded. The leds > are in parallel. > > A value to me of the LM317 is to be able to maintain constant > brightness of multiple leds (I plan to use all the same white > leds with colored lenses for colors). The LM317 is from Radio Shack > and I have only used the circuit on the back of the box-LM317, a > resistor, and a rheostat, 3 parts. Could I wire a backup with a zener > diode for a constant brightness? > > However, I have been told this LM317 won't work, that I need Pulse > Width Modulation. I'm not sure why, the LM317 seems to do what I want > at least on my desk at home, is cheap and low parts count. I would > appreciate any reasons this would not be a proper way to control > multiple identical leds-rf production? Skip Simpson > >================ > > ________________________________ Message 35 ____________________________________ Time: 08:03:20 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: fat wire - skinny wires --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 12:32 PM 10/2/2006 -0400, you wrote: >--> AeroElectric-List message posted by: Ernest Christley > > >I seem to remember there being some rationale for not running fat wires in >the same bundle with skinny wires, but I can find a specific reference to >it in the "Aero-electric Connenction". Does such a rationale exist, or am >I suffering from delusions of toxic aircraft chemical fumes? That was a tongue-in-cheek reference to the fact that the FAT wires are those that carry largest system currents, generate the largest local magnetic fields and TEND to be ranked on the antagonistic side for noise. Audio, signal and small control wires are SKINNY types that TEND to be potential victims. Having said all that, it's easy to design systems having a mix of antagonistic and victim wires in very close proximity to each other in same bundles. But it does take some time, attention and experience to do this with consistent success. >My #2 battery cable currently follows a rather tortuous path from the >tailpost to the front of the plane, and I could be a lot simple (and a few >pounds lighter), if it just ran down the side with a bunch of wires that >include microphone/headphone leads, taillight, tail strobe, fuel pump >powere, and a linear actuator control leads. As long as you've followed the guidelines for avoiding multiple grounds (ground loops) within single systems, the noise risk for bundling the wires you've listed is very low. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 36 ____________________________________ Time: 09:07:19 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Connectors vs. Straight Wire --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:56 PM 10/2/2006 -0500, you wrote: >--> AeroElectric-List message posted by: "Jim Baker" > > > I guess I'm trying to say that anytime you added un-needed connections > to a particular system > > you are just asking for longer term troubles and an overall reduction > in reliability. >____________________________________________ > >Spot on! Besides, you'll have a lot of the panel terminated in >connectors of one sort or another anyway....how hard to remove >those..... > >Tho I kinda wish the D-sub folks would go back to the old >Centronics wire bail form of shell attachment. No trying to get >the screw driver on the screw head in a spot you can't easily see. There ARE wire bails for keeping d-subs together. My favorite for cable-to-cable d-subs is remove the jack-screw hardware and use tye-wraps to keep them together. Also, I'd ALWAYS use the machined d-sub pins. They're of the same pedigree as the older and larger 'Cannon' plugs, etc. I'm REALLY disappointed that folks who sell really expensive avionics ship those sheet-metal, b-crimp pins with their radios. Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 37 ____________________________________ Time: 09:08:39 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: battery cables & Relays 'G's" skunk stink --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 05:09 PM 10/2/2006 +0000, you wrote: >--> AeroElectric-List message posted by: > >Hello Eric > >You wrote: > >"So the manufacturer says, "mount plunger vertical, cap down" > >I have never taken apart or looked very close at the relay that is being >talked about. See: http://www.aeroelectric.com/Pictures/Contactors/S701-1a.jpg http://www.aeroelectric.com/Pictures/Contactors/S701-1b.jpg http://www.aeroelectric.com/Pictures/Contactors/S701-1c.jpg http://www.aeroelectric.com/Pictures/Contactors/S701-1e.jpg http://www.aeroelectric.com/Pictures/Contactors/S701-1f.jpg Bob . . . --------------------------------------------------------- < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > --------------------------------------------------------- ________________________________ Message 38 ____________________________________ Time: 09:14:01 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: battery cables & Relays 'G's" skunk stink --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:59 AM 10/2/2006 -0500, you wrote: >--> AeroElectric-List message posted by: Dave N6030X > >Anybody have a centrifuge with accelerometer and want to conduct a little >experiment? > >Dave Morris I've done this already . . . but the rationale for mounting the contactor in any particular orientation has yet to be supported by the underlying simple-ideas. Yes, that's what the data sheet says but fails to explain why. An there's a famous Tyco white paper that makes some perfectly good measurements from which the authors then infer but never demonstrate deleterious effects that are not driven by the same science. There IS a reason why mounting the contactor under discussion cap down is a good idea and we've already hat-danced around it . . . and it's for consideration of g-forces. Bob . . .