---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 04/08/03: 32 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:38 AM - Re: Must strobe feed wires be shielded? (Cy Galley) 2. 05:07 AM - Re: Must strobe feed wires be shielded? (Jon Finley) 3. 05:37 AM - Re: Must strobe feed wires be shielded? (rondefly) 4. 06:46 AM - Re: Z-14 Interface with FADEC (Robert L. Nuckolls, III) 5. 06:46 AM - Re: Must strobe feed wires be shielded? (Shannon Knoepflein) 6. 06:49 AM - AutoE-bus'Witch (Eric M. Jones) 7. 06:52 AM - Re: Must strobe feed wires be shielded? (Robert L. Nuckolls, III) 8. 06:55 AM - Crowbar OVM (Eric M. Jones) 9. 07:10 AM - Re: Must strobe feed wires be shielded? (BobsV35B@aol.com) 10. 07:48 AM - Re: Must strobe feed wires be shielded? (Shannon Knoepflein) 11. 09:56 AM - Re: DRE-244e Intercom wiring (James E. Clark) 12. 10:02 AM - Instrument Panel Lights (Julia) 13. 10:28 AM - Fluxuating Amp meter (Terry Lamp) 14. 11:04 AM - Re: Fluxuating Amp meter (Rhett Westerman) 15. 02:08 PM - Re: Instrument Panel Lights (Julia) 16. 02:17 PM - Re: Instrument Panel Lights (Julia) 17. 03:47 PM - Harware locations versus noise. (Robert L. Nuckolls, III) 18. 04:37 PM - Re: Re: E.I. instruments need pampering? (Rino) 19. 05:00 PM - Re: Re: E.I. instruments need pampering? (Paul Messinger) 20. 05:53 PM - Re: Re: E.I. instruments need pampering? (Matt Prather) 21. 07:28 PM - Re: Re: E.I. instruments need pampering? (Cy Galley) 22. 07:52 PM - Re: Re: E.I. instruments need pampering? (Robert L. Nuckolls, III) 23. 07:54 PM - Re: Re: E.I. instruments need pampering? (Robert L. Nuckolls, III) 24. 08:26 PM - Approach-Systems Avionics Wiring System (DeWitt (Dee) Whittington) 25. 08:34 PM - Re: Must strobe feed wires be shielded? (BobsV35B@aol.com) 26. 08:58 PM - Re: Re: E.I. instruments need pampering? (Paul Messinger) 27. 08:58 PM - Re: Re: E.I. instruments need pampering? (Paul Messinger) 28. 08:58 PM - Re: Re: E.I. instruments need pampering? (Paul Messinger) 29. 09:05 PM - THANK YOU BOB! YOU ARE PROVIDING A GREAT SERVICE (Paul Messinger) 30. 09:22 PM - Re: Must strobe feed wires be shielded? (Richard E. Tasker) 31. 09:23 PM - Re: Re: E.I. instruments need pampering? (Robert McCallum) 32. 10:37 PM - FS: MX20 (richard@riley.net) ________________________________ Message 1 _____________________________________ Time: 01:38:34 AM PST US From: "Cy Galley" Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: "Cy Galley" Go to an electrician and get some wire pulling lube. Chamfer the tube opening and have a go at it with all the wires at once. You can use the tube as the ground wire if cleaned, using Aluminum wire connection compound and appropriate clamps. Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh Editor, EAA Safety Programs cgalley@qcbc.org or experimenter@eaa.org Always looking for articles for the Experimenter ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 11:14 PM 4/7/2003 -0500, you wrote: > >--> AeroElectric-List message posted by: "Sam Hoskins" > > > > > >Thanks for the prompt reply, Bob. > > > >The problem is, I'm running wire for the strobe and the position lights > >through a narrow (3/8" I.D.?) piece of tubing that runs down through my > >composite wing. I installed this tube 15 years ago when I built the wing > >and there is no practical way to enlarge it. I hope to squeeze all the > >wires through this opening. My reasoning is that I could run 5 pieces of > >18AWG more easily than a cable and the two for the position lights. > > > >Sam > > Understand . . . no magic wands I can wave here > and make it okay and I've never had the chance > to try it myself. You're charting new territory. > Hope it works okay. > > Bob . . . > > ________________________________ Message 2 _____________________________________ Time: 05:07:01 AM PST US From: "Jon Finley" Subject: RE: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: "Jon Finley" Is it possible for Sam to use one wire for each strobe using the center conductor for positive current and the shield for the negative (Instead of two wires - one for positive and one for ground)?? Could the same thing be done for the position light? Jon Finley N90MG Q2 - Subaru EJ-22 DD - 440 Hrs. TT - 0 Hrs Engine Apple Valley, Minnesota http://www.FinleyWeb.net/default.asp?id=96 > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On > Behalf Of Sam Hoskins > Sent: Monday, April 07, 2003 11:15 PM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? > > > --> AeroElectric-List message posted by: "Sam Hoskins" > --> > > Thanks for the prompt reply, Bob. > > The problem is, I'm running wire for the strobe and the > position lights through a narrow (3/8" I.D.?) piece of tubing > that runs down through my composite wing. I installed this > tube 15 years ago when I built the wing and there is no > practical way to enlarge it. I hope to squeeze all the wires > through this opening. My reasoning is that I could run 5 > pieces of 18AWG more easily than a cable and the two for the > position lights. > > Sam > > ----- Original Message ----- > From: "Robert L. Nuckolls, III" > To: > Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? > > > > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > > > At 09:11 PM 4/7/2003 -0500, you wrote: > > >--> AeroElectric-List message posted by: "Sam Hoskins" > > > > > > > > >Must strobe feed wires be shielded? I am cobbling > together a strobe > system, > > >using Whelen lights and I intend to buy one of those power > supplies > > >from strobes-r-us.com. I wish to mount the PS somewhere in the > > >center > section. > > > > > >Can I just run regular 18AWG wire from the PS to the wing tips? > > > > > > These wired DO carry fast-risetime voltage and current pulses > > that are worthy of shields and the twisted-trio configuration > > supplied with a contemporary strobe installation kit. > > > > Why would you NOT want to shield it? The wire isn't expensive. > > But then, you could give it a try. The outcome cannot > be anything > > worse than having to replace the wire later. > > > > > > Bob . . . > > ________________________________ Message 3 _____________________________________ Time: 05:37:21 AM PST US From: "rondefly" Subject: RE: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: "rondefly" My question to Jon's suggestion would be, If you go that way why use shielded at all. Wouldn't you be taking away the shield by having it be part of the conductor? You can get shelding by itself and just put it where it will interfere with other circuits and use 18AWG to fit in the tubing. Ron Triano Quicker one Q-200, 90% Done with 90% to go -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Jon Finley Subject: RE: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: "Jon Finley" Is it possible for Sam to use one wire for each strobe using the center conductor for positive current and the shield for the negative (Instead of two wires - one for positive and one for ground)?? Could the same thing be done for the position light? Jon Finley N90MG Q2 - Subaru EJ-22 DD - 440 Hrs. TT - 0 Hrs Engine Apple Valley, Minnesota http://www.FinleyWeb.net/default.asp?id=96 > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On > Behalf Of Sam Hoskins > Sent: Monday, April 07, 2003 11:15 PM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? > > > --> AeroElectric-List message posted by: "Sam Hoskins" > --> > > Thanks for the prompt reply, Bob. > > The problem is, I'm running wire for the strobe and the > position lights through a narrow (3/8" I.D.?) piece of tubing > that runs down through my composite wing. I installed this > tube 15 years ago when I built the wing and there is no > practical way to enlarge it. I hope to squeeze all the wires > through this opening. My reasoning is that I could run 5 > pieces of 18AWG more easily than a cable and the two for the > position lights. > > Sam > > ----- Original Message ----- > From: "Robert L. Nuckolls, III" > To: > Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? > > > > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > > > At 09:11 PM 4/7/2003 -0500, you wrote: > > >--> AeroElectric-List message posted by: "Sam Hoskins" > > > > > > > > >Must strobe feed wires be shielded? I am cobbling > together a strobe > system, > > >using Whelen lights and I intend to buy one of those power > supplies > > >from strobes-r-us.com. I wish to mount the PS somewhere in the > > >center > section. > > > > > >Can I just run regular 18AWG wire from the PS to the wing tips? > > > > > > These wired DO carry fast-risetime voltage and current pulses > > that are worthy of shields and the twisted-trio configuration > > supplied with a contemporary strobe installation kit. > > > > Why would you NOT want to shield it? The wire isn't expensive. > > But then, you could give it a try. The outcome cannot > be anything > > worse than having to replace the wire later. > > > > > > Bob . . . > > ________________________________ Message 4 _____________________________________ Time: 06:46:33 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Z-14 Interface with FADEC --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:49 PM 4/7/2003 -0700, you wrote: >--> AeroElectric-List message posted by: "Tom Schiff" > >I recently read a article in a Motorcycle magazine that related the >troubleshooting of a Honda Gold Wing 1800 (a recent model). The owner >was on a long cross country trip and stopped for lunch. When he returned >the starter would spin the motor but it wouldn't start. Two Honda >dealerships, much conferring with Honda, and many thousands of dollars >of troubleshooting later the bike would still not start. The editor of >the magazine was called in to see if he could help. I brought a new >battery with him and a volt meter. He determined that when the starter >was cranking the original battery voltage would drop below 10 volts. He >installed the new battery and the bike roared to life. Is this what the >FADEC's are going to bring to the aviation world? Only when the designers don't understand the world in which they propose to sell product. When consumers buy their products anyhow and quietly work around the shortcomings, there will be no pressure to change . . . Folks who make the "rules" don't understand the world they make rules about either so we can't look for help there. It's up to the knowledgeable consumer to vote with their checkbook and communicate good critical review by means of their choice. Bob . . . ________________________________ Message 5 _____________________________________ Time: 06:46:33 AM PST US From: "Shannon Knoepflein" Subject: RE: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: "Shannon Knoepflein" Since we are on the strobe kick again, I never have convinced myself that 18 gauge is necasarry with the Whelen strobes. 22 certainly would be easier for Sam to run in his small tube. It seems Old Bob has run 22 with success. If they have 21J of energy, which with the Cometflash is spread out in 4 pulses over 200ms, each pulse is 5.25J in 2ms. At 500 volts, 5.25J, 2ms, that equates to 5.25A peak. Over the duration of the 21J Cometflash, 500V, 200ms, that works out to be an average current of .21A. Over an entire minute which is 45 pulses according to Whelen, 945J, 500V, 60s, figures out at 0.03A average. At 5.25A, the I 2R losses are 11W based on 22 gauge, 16 ohm/1000, 25' run. Over the duration of the 21J Cometflash, 0.08W. Over the entire minute, 0.0004W. None of this seems to concern me so I don't see the need for anything over 22 gauge. I know there must be something, so WHAT AM I MISSING? --- Shannon Knoepflein <---> kycshann@kyol.net ________________________________ Message 6 _____________________________________ Time: 06:49:57 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: AutoE-bus'Witch --> AeroElectric-List message posted by: "Eric M. Jones" I am designing a switch module called the "AutoE-bus'Witch" that does the following: It contains the E-bus switch, the bus isolating diode, and a low voltage warning light. Exactly how this device will function is still in doubt, and suggestions would be appreciated. Here's what I think so far: (ON-ON-ON toggle switch): General notes--Isolator Diode always active, LED on switch is red/green and red LED on panel have bright/dim jumper. Device is for 14.5 VDC (key parts are not available in higher voltage for now but will be later). Led color always indicates status of main bus volts. Up Position-ON; Aux power selected ON. LED red if Main Bus Volts Low, otherwise green. Center Position-- AUTO; LED normally green, automatic switch aux power to E-bus if needed. LED then red Down Position-- OFF; E-bus switch open (OFF), LED normally OFF but LED red if Main Bus Volts Low. Questions: What max sustained current is expected through the E-bus switch? Is the control logic here okay? What other features might be desirable in this "Single-Switch Solution". Thanks for all your help. Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones@charter.net When trouble arises and things look bad, there is always one individual who perceives a solution and is willing to take command. Very often, that individual is crazy. --Dave Barry ________________________________ Message 7 _____________________________________ Time: 06:52:03 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:06 AM 4/8/2003 -0500, you wrote: >--> AeroElectric-List message posted by: "Jon Finley" > >Is it possible for Sam to use one wire for each strobe using the center >conductor for positive current and the shield for the negative (Instead >of two wires - one for positive and one for ground)?? Could the same >thing be done for the position light? Sharing ground between the two systems would couple strobe tube noises right into the 14v distribution system any time the nav lights are on. Shields can be used for effective ground returns and a single shielded wire might go into a tight tube easier than two separate strands. Sam, you might see if you can get a shielded trio and a shielded single to share the tube you have. If push comes to shove, you might consider dropping your strobe wires down to a 22AWG trio . . . that was discussed earlier on the list. Bob . . . ________________________________ Message 8 _____________________________________ Time: 06:55:04 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: Crowbar OVM --> AeroElectric-List message posted by: "Eric M. Jones" In my little non-crowbar OVM (doesn't blow a fuse or trip a breaker...just disconnects the line), There is a glitch filter to take care of nuisance trips. I haven't yet sold one of these because I can't get any test feedback. (Sitting in the shell of my Glastar going Vroom Vroom doesn't do it.) Anyone interested in testing it? Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones@charter.net "Nothing is too wonderful to be true." - James Clerk Maxwell, discoverer of electromagnetism "Too much of a good thing can be wonderful." - Mae West, discoverer of personal magnetism ________________________________ Message 9 _____________________________________ Time: 07:10:30 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 4/8/2003 8:47:03 AM Central Standard Time, kycshann@kyol.net writes: > Since we are on the strobe kick again, I never have convinced myself > that 18 gauge is necessary with the Whelen strobes. 22 certainly would > be easier for Sam to run in his small tube. It seems Old Bob has run 22 > with success. > Good Morning Shannon, Just for what it's worth, my tip tanks came from the manufacturer with a one quarter inch OD aluminum tube glassed in place to serve as a conduit to the running lights. I don't recall the dimensions just now, but I think that tubing has an ID around .185 inch. I measured #22 Tefzel wire and found that it measured something under .060. That allowed seven wires to fit through the tubing comfortably. I had planned on using wire lube (as suggested by Cy) and pulling it through with a one wire snake. However, I bundled the seven wires together, taped the end tightly and, using another old house wiring technique, just shoved the bundle through the conduit. It worked even better than I had anticipated. I have had no noise in the audio system and the strobes seem to flash quite brightly. As I mentioned before, I did check with Whelen before I decided on that course of action. They thought it should be OK. It was, and still IS! Happy Skies, Old Bob ________________________________ Message 10 ____________________________________ Time: 07:48:31 AM PST US From: "Shannon Knoepflein" Subject: RE: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: "Shannon Knoepflein" Thanks Bob, appreciate the reply. One more question if you don't mind. Which power supply do you have and do you know the amount of energy it puts out per flash? Thanks for the help. --- Shannon Knoepflein <---> kycshann@kyol.net -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of BobsV35B@aol.com Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 4/8/2003 8:47:03 AM Central Standard Time, kycshann@kyol.net writes: > Since we are on the strobe kick again, I never have convinced myself > that 18 gauge is necessary with the Whelen strobes. 22 certainly would > be easier for Sam to run in his small tube. It seems Old Bob has run 22 > with success. > Good Morning Shannon, Just for what it's worth, my tip tanks came from the manufacturer with a one quarter inch OD aluminum tube glassed in place to serve as a conduit to the running lights. I don't recall the dimensions just now, but I think that tubing has an around .185 inch. I measured #22 Tefzel wire and found that it measured something under .060. That allowed seven wires to fit through the tubing comfortably. I had planned on using wire lube (as suggested by Cy) and pulling it through with a one wire snake. However, I bundled the seven wires together, taped the end tightly and, using another old house wiring technique, just shoved the bundle through the conduit. It worked even better than I had anticipated. I have had no noise in the audio system and the strobes seem to flash quite brightly. As I mentioned before, I did check with Whelen before I decided on that course of action. They thought it should be OK. It was, and still IS! Happy Skies, Old Bob ________________________________ Message 11 ____________________________________ Time: 09:56:11 AM PST US From: "James E. Clark" Subject: RE: AeroElectric-List: DRE-244e Intercom wiring --> AeroElectric-List message posted by: "James E. Clark" When I go to the airport I will see if I can get a copy of it for you as well. Great intercom. Great people too. James > -----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, April 07, 2003 7:00 PM > To: aeroelectric-list@matronics.com > Subject: Re: AeroElectric-List: DRE-244e Intercom wiring > > > --> AeroElectric-List message posted by: "Robert L. Nuckolls, > III" > > At 03:12 PM 4/7/2003 -0500, you wrote: > >--> AeroElectric-List message posted by: "Phil Birkelbach" > > > > > >I bought a DRE-244e Intercom off of Ebay and it came without any wiring > >diagrams. If anybody has one of these units could I get wiring > diagram or a > >pinout description? Thanks. > > That one's not in my list of installation drawings. > Try contacting the manufacturer. The webpage for > your intercom is at: > http://www.drecomm.com/244eproduct.htm > Their customer service department can be > e-mailed at: > > mailto:cs@drecomm.com > > > Bob . . . > > -------------------------------------------- > ( Knowing about a thing is different than ) > ( understanding it. One can know a lot ) > ( and still understand nothing. ) > ( C.F. Kettering ) > -------------------------------------------- > > ________________________________ Message 12 ____________________________________ Time: 10:02:59 AM PST US From: Julia Subject: AeroElectric-List: Instrument Panel Lights RV7 Matronics List --> AeroElectric-List message posted by: Julia I bought a bunch of different panel lights and LED's from various companies - I need one for low oil pressure, one for low fuel pressure, and one for low voltage warning lights. Hands down the B&C Electrical - # S-888-1-2 - light is best I have seen. You can get it in different colors and it's $12.00 - save yourself the trouble and get one of these first - just get one and you'll see what i mean. Many of the LED's were not bright enough and some you could not see very well if it was mounted on the right side of the panel and you were on the left side. my 2 cents for the day. Sun'N Fun was a blast - the RV is the right thing to be building. In the lower price range the Zenith 601 was a hot ticket. --------------------------------- ________________________________ Message 13 ____________________________________ Time: 10:28:20 AM PST US Subject: AeroElectric-List: Fluxuating Amp meter From: "Terry Lamp" 04/08/2003 01:29:54 PM --> AeroElectric-List message posted by: "Terry Lamp" I just started flying my new Long EZ and noticed that the VM 1000 amp meter fluxuates from 11 to 8 to 6 to 4 tahn recycles. This is about a 30 sec cycle. While flying, about 2400 RPM. Inductive pickup is around the cable from the Nipindenso alternator to the battery. Wired pretty much as per Z-9 and run the LAR3 from B&C. Is this a normal reading? Running strobes, one elec. ign., Garmin 150XL and and intercomm. Thanks, Terry Long EZ Ohio ************************************************************************* *****************Confidentiality Notice:****************************** ************************************************************************* The information contained in this e-mail message, including any attachments, is intended only for use of the individual or entity named above (addressee). This e-mail may contain information that is privileged, confidential and/or otherwise exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, any disclosure, dissemination, distribution, copying or other use of the communication or its substance is prohibited. If you have received this e-mail in error, please reply to this e-mail indicating you are not the intended recipient and immediately destroy all copies of this e-mail. Receipt by anyone other than the intended recipient is not a waiver of any privileged information. ********************************************************************************** *eSafe scanned this email for viruses, vandals and malicious content* ********************************************************************************** ________________________________ Message 14 ____________________________________ Time: 11:04:57 AM PST US From: "Rhett Westerman" Subject: RE: AeroElectric-List: Fluxuating Amp meter --> AeroElectric-List message posted by: "Rhett Westerman" I would say that fluctuation is extreme. Mine fluxuates too but between 0 and 6. I have adjusted the zero output per vision but have not replaced the unit as vision says that it is likely not bad. It is just annoying as I have to keep some current draw on to stop the low amp beeps. I've tried e/t with grounding etc and no joy. best, Rhett -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Terry Lamp Subject: AeroElectric-List: Fluxuating Amp meter --> AeroElectric-List message posted by: "Terry Lamp" I just started flying my new Long EZ and noticed that the VM 1000 amp meter fluxuates from 11 to 8 to 6 to 4 tahn recycles. This is about a 30 sec cycle. While flying, about 2400 RPM. Inductive pickup is around the cable from the Nipindenso alternator to the battery. Wired pretty much as per Z-9 and run the LAR3 from B&C. Is this a normal reading? Running strobes, one elec. ign., Garmin 150XL and and intercomm. Thanks, Terry Long EZ Ohio ************************************************************************* *****************Confidentiality Notice:****************************** ************************************************************************* The information contained in this e-mail message, including any attachments, is intended only for use of the individual or entity named above (addressee). This e-mail may contain information that is privileged, confidential and/or otherwise exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, any disclosure, dissemination, distribution, copying or other use of the communication or its substance is prohibited. If you have received this e-mail in error, please reply to this e-mail indicating you are not the intended recipient and immediately destroy all copies of this e-mail. Receipt by anyone other than the intended recipient is not a waiver of any privileged information. **************************************************************************** ****** *eSafe scanned this email for viruses, vandals and malicious content* **************************************************************************** ****** ________________________________ Message 15 ____________________________________ Time: 02:08:43 PM PST US From: Julia Subject: Re: AeroElectric-List: Instrument Panel Lights --> AeroElectric-List message posted by: Julia http://www.bandc.biz/ above is the link to the site with the light for sale Julia wrote:--> AeroElectric-List message posted by: Julia I bought a bunch of different panel lights and LED's from various companies - I need one for low oil pressure, one for low fuel pressure, and one for low voltage warning lights. Hands down the B&C Electrical - # S-888-1-2 - light is best I have seen. You can get it in different colors and it's $12.00 - save yourself the trouble and get one of these first - just get one and you'll see what i mean. Many of the LED's were not bright enough and some you could not see very well if it was mounted on the right side of the panel and you were on the left side. my 2 cents for the day. Sun'N Fun was a blast - the RV is the right thing to be building. In the lower price range the Zenith 601 was a hot ticket. --------------------------------- --------------------------------- ________________________________ Message 16 ____________________________________ Time: 02:17:54 PM PST US From: Julia Subject: Re: AeroElectric-List: Instrument Panel Lights --> AeroElectric-List message posted by: Julia And on the site the part # is WLA - not what I previously mentioned - sorry about that Julia wrote:--> AeroElectric-List message posted by: Julia http://www.bandc.biz/ above is the link to the site with the light for sale Julia wrote:--> AeroElectric-List message posted by: Julia I bought a bunch of different panel lights and LED's from various companies - I need one for low oil pressure, one for low fuel pressure, and one for low voltage warning lights. Hands down the B&C Electrical - # S-888-1-2 - light is best I have seen. You can get it in different colors and it's $12.00 - save yourself the trouble and get one of these first - just get one and you'll see what i mean. Many of the LED's were not bright enough and some you could not see very well if it was mounted on the right side of the panel and you were on the left side. my 2 cents for the day. Sun'N Fun was a blast - the RV is the right thing to be building. In the lower price range the Zenith 601 was a hot ticket. --------------------------------- --------------------------------- --------------------------------- ________________________________ Message 17 ____________________________________ Time: 03:47:03 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Harware locations versus noise. --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >Comments/Questions: Alternator Voltage Regulators are these considered >"noisy" items that sould be on the hot side of the firewall away from >radios or are they benign and canbe located on the cabin side without any >noise problems? You can mount them where-ever . . . if there are any noise issues, they will involve CONDUCTED noise that travels over wiring as opposed to RADIATED noise that jumps from antagonist to victim. Mount them where it makes the most sense for ease of maintenance. Practice good system architecture as described in appendix Z drawings and the likelihood of any noise problems is low and easy to fix if they do show up. Bob . . . -------------------------------------------- ( Knowing about a thing is different than ) ( understanding it. One can know a lot ) ( and still understand nothing. ) ( C.F. Kettering ) -------------------------------------------- ________________________________ Message 18 ____________________________________ Time: 04:37:46 PM PST US From: Rino Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: Rino > > Where am I going wrong? Where did the hundreds > who have participated in the crafting and maintenance > of DO-160 over the past two decades go astray? > > Bob . . What about the billions of cars on the road today WITHOUT an avionics SWITCH ? Do they not have any electronics on board? Rino ________________________________ Message 19 ____________________________________ Time: 05:00:35 PM PST US From: "Paul Messinger" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: "Paul Messinger" Snipped from Bob's comments in reply to the EI discussion See My comments following yours below > Perhaps I can suggest this. Take a scope and go look > at the output from the cigar lighter on a car. Set up to > + slope trigger at say, 20 volts and then crank the engine. > My Tektronix 220 could not capture a single transient at > ANY horizontal resolution. Tried triggering on - slope > at zero volts. Same result. I'd say my GMC van is roughly > equal to C-150 for cranking currents and DC system impedance. > > This is typical of what I've captured on a number of > airplanes ranging from C-150 to Beechjets over the past > 25 years measured with all manner of scopes, chart > recorders and high speed (8,000 samples/second) > data acquisition systems. > > Where am I going wrong? Where did the hundreds > who have participated in the crafting and maintenance > of DO-160 over the past two decades go astray? > > Bob . . . Bob; I cannot find any info on your Tek 220 but I assume its similar to the Tek 221, a 5 mHz scope. Also 8,000 samples per sec is also extremely slow. It takes more like 200,000,000 SPS. That scope is way too slow to see transients that I have observed during starting and stopping of a bare bones auto setup with all the normal built in suppression removed. Sure it will display a huge very slow transient but not the fast ones or the ringing multiple transients usually following the major event. This takes a scope of triggering on a 50Mhz (nominal) or higher frequency pulse (rise times of a few nanoseconds), having a horizontal single sweep speed set to at least 10 nanoseconds per division and either very high speed storage or a camera. Most of the available analog storage scopes are too slow in the storage mode. A single sweep is too faint for normal single shot vu and only the higher speed horizontal triggering modules will even trigger. As the transient is a single shot event there must be some way to hole it for human display. Thus either a fast storage scope or scope camera. The best way to see if there is a transient is with a good Transient Voltmeter but they are expensive and special purpose. Yet these sharp fast high voltage transients will pass thru a 10-100 mfd electrolytic cap on the input of an electronic instrument and damage internal CMOS etc IC's. The cap's reactance (in ohms) increases to a large number at the frequencies of interest. I have demonstrated this years ago and thus I install transorbs in all my designs. This is the design choice of the auto industry and we should learn from their experience. For the last 20 or more years autos have Transorbs built into most (if not all) electronic modules, including the IGN system. Not usually a discrete item but part of one or more IC's. These Transorbs are special super fast response Zener diodes, in fact normal Zener diodes are not fast enough to stop the transient from getting past. Thus if you try to find transients on most any modern automobile you will not find them even with the proper equipment. The many internal Transorbs are clipping them on the way to the Lighter so there are none left to detect. On the other hand it would appear that even modern aircraft electrical designs (consider the FADEC low V issues) fail to address the "lessens learned" in the auto industry regarding starting and shutdown voltages and transients (which in many cases cannot even be seen with the normally used test equipment). While the transients I am addressing are not always present, they sometimes do damage equipment and unless special test procedures are used they are simply not seen and thus do not exist in the minds of many design engineers. In conclusion: I am saying I do not think your test methods ( I know it, if your Tek scope is as I believe it is regarding frequency response etc.) are capable of seeing potentially damaging transients and your test article (an auto) has already designed in transient suppressors so any transients you are looking for are already clipped and thus even with proper test setup would not be found. The auto industry learned the hard way and as near as I can find, many in the aircraft industry are not considering the lessens learned in the auto industry. As aircraft electrical systems move from mags and generators to alternators and solid state electronics, and avionics become more complex, the auto and aircraft electrical design needs will continue to converge. This is not to say the aircraft instruments/avionics should not be designed to withstand the fast transients and low voltage starting issues, but knowing how to protect for fast transients (for under a dollar) is a simple fix for homebuilders and the low voltage issues with FADEC, RMI and EI among others is up to the individual designer to consider. Properly selected and connected transorbs and a backup battery are simple solutions IF your decision is to use an instrument that is not fully internally protected. The key to me is knowing what is needed. Paul ________________________________ Message 20 ____________________________________ Time: 05:53:44 PM PST US Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" > --> AeroElectric-List message posted by: "Paul Messinger" > > > Snipped from Bob's comments in reply to the EI discussion > > See My comments following yours below > >> Perhaps I can suggest this. Take a scope and go look snip > > This takes a scope of triggering on a 50Mhz (nominal) or higher > frequency pulse (rise times of a few nanoseconds), having a horizontal > single sweep speed set to at least 10 nanoseconds per division and > either very high speed storage or a camera. Most of the available analog > storage scopes are too slow in the storage mode. A single sweep is too > faint for normal single shot vu and only the higher speed horizontal > triggering modules will even trigger. As the transient is a single shot > event there must be some way to hole it for human display. Thus either a > fast storage scope or scope camera. Do you know what is causing these high frequency/energy transients on the power bus? I am guess it could be arcing of relay contacts. I also wonder how far from the transient source is the energy carried before being rolled-off in the uncontrolled impedance environment that is the powerbus. Interesting discussion. Regards, Matt- N34RD ________________________________ Message 21 ____________________________________ Time: 07:28:48 PM PST US From: "Cy Galley" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: "Cy Galley" So why not install a transorb in the electronic supply line and be done with the problem. Are they that expensive? Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh Editor, EAA Safety Programs cgalley@qcbc.org or experimenter@eaa.org Always looking for articles for the Experimenter ----- Original Message ----- From: "Paul Messinger" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? > --> AeroElectric-List message posted by: "Paul Messinger" > > Snipped from Bob's comments in reply to the EI discussion > > See My comments following yours below > > > Perhaps I can suggest this. Take a scope and go look > > at the output from the cigar lighter on a car. Set up to > > + slope trigger at say, 20 volts and then crank the engine. > > My Tektronix 220 could not capture a single transient at > > ANY horizontal resolution. Tried triggering on - slope > > at zero volts. Same result. I'd say my GMC van is roughly > > equal to C-150 for cranking currents and DC system impedance. > > > > This is typical of what I've captured on a number of > > airplanes ranging from C-150 to Beechjets over the past > > 25 years measured with all manner of scopes, chart > > recorders and high speed (8,000 samples/second) > > data acquisition systems. > > > > Where am I going wrong? Where did the hundreds > > who have participated in the crafting and maintenance > > of DO-160 over the past two decades go astray? > > > > Bob . . . > > Bob; > > I cannot find any info on your Tek 220 but I assume its similar to the Tek > 221, a 5 mHz scope. Also 8,000 samples per sec is also extremely slow. It > takes more like 200,000,000 SPS. > > That scope is way too slow to see transients that I have observed during > starting and stopping of a bare bones auto setup with all the normal built > in suppression removed. > > Sure it will display a huge very slow transient but not the fast ones or the > ringing multiple transients usually following the major event. > > This takes a scope of triggering on a 50Mhz (nominal) or higher frequency > pulse (rise times of a few nanoseconds), having a horizontal single sweep > speed set to at least 10 nanoseconds per division and either very high speed > storage or a camera. Most of the available analog storage scopes are too > slow in the storage mode. A single sweep is too faint for normal single shot > vu and only the higher speed horizontal triggering modules will even > trigger. As the transient is a single shot event there must be some way to > hole it for human display. Thus either a fast storage scope or scope camera. > > The best way to see if there is a transient is with a good Transient > Voltmeter but they are expensive and special purpose. > > Yet these sharp fast high voltage transients will pass thru a 10-100 mfd > electrolytic cap on the input of an electronic instrument and damage > internal CMOS etc IC's. The cap's reactance (in ohms) increases to a large > number at the frequencies of interest. I have demonstrated this years ago > and thus I install transorbs in all my designs. This is the design choice of > the auto industry and we should learn from their experience. > > For the last 20 or more years autos have Transorbs built into most (if not > all) electronic modules, including the IGN system. Not usually a discrete > item but part of one or more IC's. These Transorbs are special super fast > response Zener diodes, in fact normal Zener diodes are not fast enough to > stop the transient from getting past. > > Thus if you try to find transients on most any modern automobile you will > not find them even with the proper equipment. The many internal Transorbs > are clipping them on the way to the Lighter so there are none left to > detect. > > On the other hand it would appear that even modern aircraft electrical > designs (consider the FADEC low V issues) fail to address the "lessens > learned" in the auto industry regarding starting and shutdown voltages and > transients (which in many cases cannot even be seen with the normally used > test equipment). > > While the transients I am addressing are not always present, they sometimes > do damage equipment and unless special test procedures are used they are > simply not seen and thus do not exist in the minds of many design engineers. > > In conclusion: > I am saying I do not think your test methods ( I know it, if your Tek scope > is as I believe it is regarding frequency response etc.) are capable of > seeing potentially damaging transients and your test article (an auto) has > already designed in transient suppressors so any transients you are looking > for are already clipped and thus even with proper test setup would not be > found. > > The auto industry learned the hard way and as near as I can find, many in > the aircraft industry are not considering the lessens learned in the auto > industry. As aircraft electrical systems move from mags and generators to > alternators and solid state electronics, and avionics become more complex, > the auto and aircraft electrical design needs will continue to converge. > > This is not to say the aircraft instruments/avionics should not be designed > to withstand the fast transients and low voltage starting issues, but > knowing how to protect for fast transients (for under a dollar) is a simple > fix for homebuilders and the low voltage issues with FADEC, RMI and EI among > others is up to the individual designer to consider. > > Properly selected and connected transorbs and a backup battery are simple > solutions IF your decision is to use an instrument that is not fully > internally protected. The key to me is knowing what is needed. > > Paul > > ________________________________ Message 22 ____________________________________ Time: 07:52:36 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 04:57 PM 4/8/2003 -0700, you wrote: >--> AeroElectric-List message posted by: "Paul Messinger" > > >Snipped from Bob's comments in reply to the EI discussion > >See My comments following yours below > > > Perhaps I can suggest this. Take a scope and go look > > at the output from the cigar lighter on a car. Set up to > > + slope trigger at say, 20 volts and then crank the engine. > > My Tektronix 220 could not capture a single transient at > > ANY horizontal resolution. Tried triggering on - slope > > at zero volts. Same result. I'd say my GMC van is roughly > > equal to C-150 for cranking currents and DC system impedance. > > > > This is typical of what I've captured on a number of > > airplanes ranging from C-150 to Beechjets over the past > > 25 years measured with all manner of scopes, chart > > recorders and high speed (8,000 samples/second) > > data acquisition systems. > > > > Where am I going wrong? Where did the hundreds > > who have participated in the crafting and maintenance > > of DO-160 over the past two decades go astray? > > > > Bob . . . > >Bob; > >I cannot find any info on your Tek 220 but I assume its similar to the Tek >221, a 5 mHz scope. Also 8,000 samples per sec is also extremely slow. It >takes more like 200,000,000 SPS. It's a 1 GigaSamples/second digital storage scope. See http://www.metricsales.com/c_tektronix/40W_10992_4.pdf It's specified as capable of capturing a 10 nS pulse. >That scope is way too slow to see transients that I have observed during >starting and stopping of a bare bones auto setup with all the normal built >in suppression removed. >Sure it will display a huge very slow transient but not the fast ones or the >ringing multiple transients usually following the major event. > >This takes a scope of triggering on a 50Mhz (nominal) or higher frequency >pulse (rise times of a few nanoseconds), having a horizontal single sweep >speed set to at least 10 nanoseconds per division and either very high speed >storage or a camera. Most of the available analog storage scopes are too >slow in the storage mode. A single sweep is too faint for normal single shot >vu and only the higher speed horizontal triggering modules will even >trigger. As the transient is a single shot event there must be some way to >hole it for human display. Thus either a fast storage scope or scope camera. > >The best way to see if there is a transient is with a good Transient >Voltmeter but they are expensive and special purpose. I've built them with fast peak-hold circuits . . . not difficult. >Yet these sharp fast high voltage transients will pass thru a 10-100 mfd >electrolytic cap on the input of an electronic instrument and damage >internal CMOS etc IC's. The cap's reactance (in ohms) increases to a large >number at the frequencies of interest. I have demonstrated this years ago >and thus I install transorbs in all my designs. This is the design choice of >the auto industry and we should learn from their experience. Sure . . . Transorbs are fine devices, we use them by the fist-full in lots of products. We also apply the usual high quality capacitors and series devices to raise the apparent source impedance of the stress . . . this is all jelly-bean technology. The stuff we bolt to airplanes is now routinely tested for the effects of lighting strike to the airframe and while it raises complexity of i/o in terms of parts count, none of the parts are expensive or exotic. >For the last 20 or more years autos have Transorbs built into most (if not >all) electronic modules, including the IGN system. Not usually a discrete >item but part of one or more IC's. These Transorbs are special super fast >response Zener diodes, in fact normal Zener diodes are not fast enough to >stop the transient from getting past. > >Thus if you try to find transients on most any modern automobile you will >not find them even with the proper equipment. The many internal Transorbs >are clipping them on the way to the Lighter so there are none left to >detect. > >On the other hand it would appear that even modern aircraft electrical >designs (consider the FADEC low V issues) . . . Yup, another big name company found that the boot in their rear was their own . . . happens all the time. > . . . fail to address the "lessens >learned" in the auto industry regarding starting and shutdown voltages and >transients (which in many cases cannot even be seen with the normally used >test equipment). Your stretching it a tad here my friend . . . define "normally used" . . . The folks who crafted DO-160 comprise the talents of hundreds of engineers from virtually every company in the US with an interest in aviation including manufacturers, consumer groups and government. If you think you and I are the only ones to ever have discussed transients, either real or imagined, you are mistaken. The equipment and test methods used to define DO-160 recommendations for testing are the best available. Experiments are repeated and/or reviewed by multiple investigators and confirmed before being pronounced valid. I can quote from my own experience but much of my success has to give credit for many lessons learned as exemplified by the contents of DO-160 and the experience-base that was tapped to create the document. And "we're" still learning. DO-160 chapters are constantly being re-evaluated and revised as new threats arise or better techniques for meeting them are devised. >While the transients I am addressing are not always present, they sometimes >do damage equipment and unless special test procedures are used they are >simply not seen and thus do not exist in the minds of many design engineers. If you believe my head is in the sand somewhere, please cite an experiment I can go duplicate that supports your assertion. Let's turn the engineering community on to a hazard heretofore unknown to the standing committee on DO-160. We can co-author a paper and become famous. >In conclusion: > I am saying I do not think your test methods ( I know it, if your Tek scope >is as I believe it is regarding frequency response etc.) are capable of >seeing potentially damaging transients and your test article (an auto) has >already designed in transient suppressors so any transients you are looking >for are already clipped and thus even with proper test setup would not be >found. Fair enough. The first time I did the automotive experiment was on my '72 or '73 Vega . . . don't think it had any transorb protected systems in it. That was when I was working at Electro-Mech and the 'scope would have been a Tek 465. My wife's uncle has an older Chevy pickup he's really proud of. I'll see if he'll let me hook my 'scope to it. But the fellow from E.I. was alluding to the existence of killer spikes far outside the range of stresses his own products could survive in spite of the fact his products could take on DO-160 without breaking a sweat. Although not stated directly, the implication is that DO-160 has badly missed the mark with respect to spikes that spark in the dark. >The auto industry learned the hard way and as near as I can find, many in >the aircraft industry are not considering the lessens learned in the auto >industry. As aircraft electrical systems move from mags and generators to >alternators and solid state electronics, and avionics become more complex, >the auto and aircraft electrical design needs will continue to converge. > >This is not to say the aircraft instruments/avionics should not be designed >to withstand the fast transients and low voltage starting issues, but >knowing how to protect for fast transients (for under a dollar) is a simple >fix for homebuilders and the low voltage issues with FADEC, RMI and EI among >others is up to the individual designer to consider. I think they HAVE taken capitalized on many lessons learned - else DO-160 would not have come into existence. Now, whether or not folks who supply product to the industry know how to take advantage of these lessons is another matter. I'm aware of discussions with folks from a REALLY BIG name company who have stepped into a $millions$ pothole for not taking time to study and use lessons learned. It's now getting down to debating the definition of "is" . . . >Properly selected and connected transorbs and a backup battery are simple >solutions IF your decision is to use an instrument that is not fully >internally protected. The key to me is knowing what is needed. Don't disagree with much of what you've written. But none of this addresses the issue with respect to E.I. To date, the writer had given no data and only regurgitated 40 year old mantras. I've asked no more of him than I would of any fellow engineer. Cite the reviewed and repeatable experiments either of his own work or that of others to support his position that explains why his customers need to pamper his products. Could he be overlooking the $1 solution? Spikes of the nature you've cited have no energy in them. Self inductance of just power lead wires significantly raises source impedance of any such spike as to render it nearly toothless. When I've watched the bus with slower equipment, my interest was in transients that carried some real energy. Those tens-of-nanosecond wide events are like cap pistols at a good July 4th celebration. They're easy to filter and/or clamp off with ordinary techniques. Whether they exist or not I can deduce no reason for a credible designer to hide behind an avionics master switch protected bus. I've designed dozens of black boxes, some that include microprocessors that run have run the DO-160 test gauntlet including lightning stroke. They all run happily tied right to the main bus of the airframe . . . I wouldn't THINK of offering a product that couldn't handle ANYTHING a normally operating airplane throws at it. As you and I have both noted, it's EASY. All I expect from E.I. is to be good engineers and back up their expectations and claims with good data from repeatable experiments, spread the word on good information, debunk bad information and make Carl Sagan proud of us all. Bob . . . ________________________________ Message 23 ____________________________________ Time: 07:54:31 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:38 PM 4/8/2003 -0300, you wrote: >--> AeroElectric-List message posted by: Rino > > > > > Where am I going wrong? Where did the hundreds > > who have participated in the crafting and maintenance > > of DO-160 over the past two decades go astray? > > > > Bob . . > > >What about the billions of cars on the road today WITHOUT an avionics >SWITCH ? Do they not have any electronics on board? sho'nuf do . . . and they all benefit from a plethora of components and techniques designed to deal comfortably with anything the car (or any other vehicle) can throw at it. It's all tinker-toy technology. See my other post. Bob . . . ________________________________ Message 24 ____________________________________ Time: 08:26:11 PM PST US From: "DeWitt (Dee) Whittington" Subject: AeroElectric-List: Approach-Systems Avionics Wiring System --> AeroElectric-List message posted by: "DeWitt (Dee) Whittington" Just got back from Sun 'n Fun. There I attended a forum presented by Approach Systems who claim to have a product that will let you "Wire an avionics stack in LESS THAN 3 hours with Fast Stack.". The packed tent heard about a system that's been on the market since Oshkosh 2002. This company makes a "hub" consisting of 8 layers of PC boards and custom built connecting cables to provide all the interconnect wiring for your avionics stack. You tell them what particular avionics items you have in your panel and how long the cables must be. However, they leave it up to you to connect buss power, ground, lighting and antennas as well as mount the avionics boxes in the panel. They suggest that it will save hours of build time and debugging, especially for the segment of the homebuilding public who dread wiring their avionics stack. Approach Systems also claims that their system makes it easy to change or add boxes in the future to your stack. Some of their systems have been put in certified aircraft with 337s. On initial hearing, seemed like these folks may have something. If you haven't heard about them, check out their web site, www.approach-systems.com Any comments from someone who has bought one of their systems or have heard their presentation? DeWitt Whittington A&P 406 N Mulberry St Richmond, VA 23220 (804) 358-4333 phone and fax dewittw@earthlink.net ________________________________ Message 25 ____________________________________ Time: 08:34:58 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 4/8/03 9:49:11 AM Central Daylight Time, kycshann@kyol.net writes: > Which power supply do you have and do you know the amount of energy it > puts out per flash? Thanks for the help. > Good Evening Shannon, I have the Whelen A490A power supplies. One on the tail and one in each wing tip. They are connected with a trigger wire so that they flash together. The ad in the Aircraft Spruce catalog says that it produces an accumulated 34 joules of energy. Any idea what that means? Happy Skies, Old Bob ________________________________ Message 26 ____________________________________ Time: 08:58:47 PM PST US From: "Paul Messinger" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: "Paul Messinger" Well under $1.00 for the larger powered ones. As far as I am concerned that would be the solution however I would put one on the unit side of the (fuse or CB) as failure of the device could produce a hard short to ground (along with perhaps dozens of other components. However they are very hard to damage. I have yet to find an auto designed device with out such protection. Not sure about items designed to be on the auto acc buss as that buss is off during engine start and or is 3 rd party designed for the acc buss. In any event the main components of the auto electic system have supression and that supression stops things before getting to the ass buss. At least that is what I have found in limited investigation of auto systems etc. Paul ----- Original Message ----- From: "Cy Galley" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? > --> AeroElectric-List message posted by: "Cy Galley" > > So why not install a transorb in the electronic supply line and be done with > the problem. Are they that expensive? > > Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh > > Editor, EAA Safety Programs > cgalley@qcbc.org or experimenter@eaa.org ________________________________ Message 27 ____________________________________ Time: 08:58:47 PM PST US From: "Paul Messinger" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: "Paul Messinger" ----- Original Message ----- From: "Rino" > > What about the billions of cars on the road today WITHOUT an avionics > SWITCH ? Do they not have any electronics on board? > > Rino In a way as the ign switch turns off the radios etc during the starting process. Paul ________________________________ Message 28 ____________________________________ Time: 08:58:47 PM PST US From: "Paul Messinger" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: "Paul Messinger" Sorry about your scope but I stand by my commenst that there is nothing to see as modern autos are already supressed. As for aircraft I do not know about the latest designs and production models. However to think that we experimental builders will always spend the big bucks for the latest state of the art in avionics is as you say head in the sand. Most of us cannot afford the latest for a $20-50K panel and need to put up with either older designs still in production and whle new not new designs. The fix is so simple. $5 worth of transorbs and the worry is gone. The transients I have seen will travel all over your system and while I agree the energi is tiny its huge to a CMOS gate in an IC. As for the experts hopefully the ones who designed the FADEC that will not work at 8V were not part of your team that came up with your new specs. I do not waht to start another time consuming discussion as again we see the same issue in a different light. Paul ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 04:57 PM 4/8/2003 -0700, you wrote: > >--> AeroElectric-List message posted by: "Paul Messinger" > > > > > >Snipped from Bob's comments in reply to the EI discussion > > > >See My comments following yours below > > > > > Perhaps I can suggest this. Take a scope and go look > > > at the output from the cigar lighter on a car. Set up to > > > + slope trigger at say, 20 volts and then crank the engine. > > > My Tektronix 220 could not capture a single transient at > > > ANY horizontal resolution. Tried triggering on - slope > > > at zero volts. Same result. I'd say my GMC van is roughly > > > equal to C-150 for cranking currents and DC system impedance. > > > > > > This is typical of what I've captured on a number of > > > airplanes ranging from C-150 to Beechjets over the past > > > 25 years measured with all manner of scopes, chart > > > recorders and high speed (8,000 samples/second) > > > data acquisition systems. > > > > > > Where am I going wrong? Where did the hundreds > > > who have participated in the crafting and maintenance > > > of DO-160 over the past two decades go astray? > > > > > > Bob . . . > > > >Bob; > > > >I cannot find any info on your Tek 220 but I assume its similar to the Tek > >221, a 5 mHz scope. Also 8,000 samples per sec is also extremely slow. It > >takes more like 200,000,000 SPS. > > It's a 1 GigaSamples/second digital storage scope. > See http://www.metricsales.com/c_tektronix/40W_10992_4.pdf > It's specified as capable of capturing a 10 nS pulse. > > >That scope is way too slow to see transients that I have observed during > >starting and stopping of a bare bones auto setup with all the normal built > >in suppression removed. > > > >Sure it will display a huge very slow transient but not the fast ones or the > >ringing multiple transients usually following the major event. > > > >This takes a scope of triggering on a 50Mhz (nominal) or higher frequency > >pulse (rise times of a few nanoseconds), having a horizontal single sweep > >speed set to at least 10 nanoseconds per division and either very high speed > >storage or a camera. Most of the available analog storage scopes are too > >slow in the storage mode. A single sweep is too faint for normal single shot > >vu and only the higher speed horizontal triggering modules will even > >trigger. As the transient is a single shot event there must be some way to > >hole it for human display. Thus either a fast storage scope or scope camera. > > > >The best way to see if there is a transient is with a good Transient > >Voltmeter but they are expensive and special purpose. > > I've built them with fast peak-hold circuits . . . not difficult. > > > >Yet these sharp fast high voltage transients will pass thru a 10-100 mfd > >electrolytic cap on the input of an electronic instrument and damage > >internal CMOS etc IC's. The cap's reactance (in ohms) increases to a large > >number at the frequencies of interest. I have demonstrated this years ago > >and thus I install transorbs in all my designs. This is the design choice of > >the auto industry and we should learn from their experience. > > Sure . . . Transorbs are fine devices, we use them by the fist-full > in lots of products. We also apply the usual high quality capacitors > and series devices to raise the apparent source impedance of the > stress . . . this is all jelly-bean technology. The stuff we bolt > to airplanes is now routinely tested for the effects of lighting > strike to the airframe and while it raises complexity of i/o in > terms of parts count, none of the parts are expensive or exotic. > > > >For the last 20 or more years autos have Transorbs built into most (if not > >all) electronic modules, including the IGN system. Not usually a discrete > >item but part of one or more IC's. These Transorbs are special super fast > >response Zener diodes, in fact normal Zener diodes are not fast enough to > >stop the transient from getting past. > > > >Thus if you try to find transients on most any modern automobile you will > >not find them even with the proper equipment. The many internal Transorbs > >are clipping them on the way to the Lighter so there are none left to > >detect. > > > >On the other hand it would appear that even modern aircraft electrical > >designs (consider the FADEC low V issues) . . . > > Yup, another big name company found that the boot > in their rear was their own . . . happens all the time. > > > > . . . fail to address the "lessens > >learned" in the auto industry regarding starting and shutdown voltages and > >transients (which in many cases cannot even be seen with the normally used > >test equipment). > > Your stretching it a tad here my friend . . . define "normally used" . . . > The folks who crafted DO-160 comprise the talents of hundreds of > engineers from virtually every company in the US with an interest > in aviation including manufacturers, consumer groups and government. > > If you think you and I are the only ones to ever have discussed > transients, either real or imagined, you are mistaken. The equipment > and test methods used to define DO-160 recommendations for testing > are the best available. Experiments are repeated and/or reviewed > by multiple investigators and confirmed before being pronounced valid. > > I can quote from my own experience but much of my success has > to give credit for many lessons learned as exemplified by > the contents of DO-160 and the experience-base that was tapped > to create the document. And "we're" still learning. DO-160 > chapters are constantly being re-evaluated and revised as > new threats arise or better techniques for meeting them are > devised. > > > >While the transients I am addressing are not always present, they sometimes > >do damage equipment and unless special test procedures are used they are > >simply not seen and thus do not exist in the minds of many design engineers. > > If you believe my head is in the sand somewhere, please cite > an experiment I can go duplicate that supports your assertion. > Let's turn the engineering community on to a hazard heretofore > unknown to the standing committee on DO-160. We can co-author > a paper and become famous. > > > >In conclusion: > > I am saying I do not think your test methods ( I know it, if your Tek scope > >is as I believe it is regarding frequency response etc.) are capable of > >seeing potentially damaging transients and your test article (an auto) has > >already designed in transient suppressors so any transients you are looking > >for are already clipped and thus even with proper test setup would not be > >found. > > Fair enough. The first time I did the automotive experiment > was on my '72 or '73 Vega . . . don't think it had any transorb > protected systems in it. That was when I was working at Electro-Mech > and the 'scope would have been a Tek 465. > > My wife's uncle has an older Chevy pickup he's really proud of. > I'll see if he'll let me hook my 'scope to it. But the fellow > from E.I. was alluding to the existence of killer spikes far > outside the range of stresses his own products could survive > in spite of the fact his products could take on DO-160 without > breaking a sweat. Although not stated directly, the implication > is that DO-160 has badly missed the mark with respect to spikes > that spark in the dark. > > > >The auto industry learned the hard way and as near as I can find, many in > >the aircraft industry are not considering the lessens learned in the auto > >industry. As aircraft electrical systems move from mags and generators to > >alternators and solid state electronics, and avionics become more complex, > >the auto and aircraft electrical design needs will continue to converge. > > > >This is not to say the aircraft instruments/avionics should not be designed > >to withstand the fast transients and low voltage starting issues, but > >knowing how to protect for fast transients (for under a dollar) is a simple > >fix for homebuilders and the low voltage issues with FADEC, RMI and EI among > >others is up to the individual designer to consider. > > I think they HAVE taken capitalized on many lessons learned - else DO-160 > would not have come into existence. Now, whether or not folks who > supply product to the industry know how to take advantage of these > lessons is another matter. I'm aware of discussions with folks from > a REALLY BIG name company who have stepped into a $millions$ pothole > for not taking time to study and use lessons learned. It's now > getting down to debating the definition of "is" . . . > > >Properly selected and connected transorbs and a backup battery are simple > >solutions IF your decision is to use an instrument that is not fully > >internally protected. The key to me is knowing what is needed. > > Don't disagree with much of what you've written. But none > of this addresses the issue with respect to E.I. To date, the > writer had given no data and only regurgitated 40 year old > mantras. I've asked no more of him than I would of any fellow > engineer. Cite the reviewed and repeatable experiments either > of his own work or that of others to support his position that > explains why his customers need to pamper his products. Could > he be overlooking the $1 solution? > > Spikes of the nature you've cited have no energy in them. > Self inductance of just power lead wires significantly > raises source impedance of any such spike as to render > it nearly toothless. When I've watched the bus with slower > equipment, my interest was in transients that carried > some real energy. Those tens-of-nanosecond wide events > are like cap pistols at a good July 4th celebration. > > They're easy to filter and/or clamp off with ordinary > techniques. Whether they exist or not I can deduce > no reason for a credible designer to hide behind an > avionics master switch protected bus. > > I've designed dozens of black boxes, some that include > microprocessors that run have run the DO-160 test > gauntlet including lightning stroke. They all run happily tied > right to the main bus of the airframe . . . I wouldn't THINK > of offering a product that couldn't handle ANYTHING a normally > operating airplane throws at it. As you and I have both noted, > it's EASY. > > All I expect from E.I. is to be good engineers and > back up their expectations and claims with good data > from repeatable experiments, spread the word on good > information, debunk bad information and make Carl > Sagan proud of us all. > > Bob . . . > > ________________________________ Message 29 ____________________________________ Time: 09:05:15 PM PST US From: "Paul Messinger" Subject: AeroElectric-List: THANK YOU BOB! YOU ARE PROVIDING A GREAT SERVICE --> AeroElectric-List message posted by: "Paul Messinger" I do not want anyone to think I am picking on Bob. He is the only one who has taken the time and interest to help the experimental aviation community build safe electrical systems. Copying SPAM Can's is not the way to go. I know of NO WHERE else where one can get good reliable info in any form much less clearly written for the masses. I have many feet of manuals, info, etc. on my shelf and find that IF I could only have one it would be Bob's bible. Yes, its on my shelf and has been for years! For anyone not a true expert (real not self proclaimed) its best to follow ALL of the info in the book. Selective use is not a good idea. Bob has developed a total safe solution to an electrical system. Its a total system and should be used as such unless Bob approves otherwise. While I disagree with Bob from time to time its perhaps only 1% of the total. Paul EAA 55789, TC, FA ________________________________ Message 30 ____________________________________ Time: 09:22:55 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Must strobe feed wires be shielded? --> AeroElectric-List message posted by: "Richard E. Tasker" > > >The ad in the Aircraft Spruce catalog says that it produces an accumulated 34 >joules of energy. Any idea what that means? > Not exactly sure what you are expecting for an answer. I'm an electrical engineer so forgive me if I tell you more than you want to know. A joule is a measurement of energy. Your 34 joules is 34 watt-seconds or 34 watts for one second. The power supply stores this amount of energy in an internal storage capacitor. When the strobe is triggered, the flash is approximately 2 milliseconds (2/1000 seconds) long, so the 34 watt-seconds is used up in the flash tube in this 2mS with the flash tube turning this electrical energy into light energy. To dissipate this 34 joules of energy the strobe tube is using the equivalent of 17,000 watts for the 2 mS duration of the flash. So your 34 joules is 34 watts for one-second or 17,000 watts for 0.002 seconds. During the time between flashes, the power supply is recharging the capacitor to get ready for the next flash. Dick Tasker ________________________________ Message 31 ____________________________________ Time: 09:23:15 PM PST US From: Robert McCallum Subject: Re: AeroElectric-List: RE: E.I. instruments need pampering? --> AeroElectric-List message posted by: Robert McCallum Paul Messinger wrote: > > > > What about the billions of cars on the road today WITHOUT an avionics > > SWITCH ? Do they not have any electronics on board? > > > > Rino > > In a way as the ign switch turns off the radios etc. during the starting > process. > > Paul The vast majority of electronics in modern cars have nothing to do with radios or anything else on the accessory buss. The electronics for the most part reside in the plethora of computers which control everything from engine management, to door locks, to air bags, NONE of which are off during engine start. (And ALL of which presumably continue working quitehappily) -- Bob McC DO NOT ARCHIVE ________________________________ Message 32 ____________________________________ Time: 10:37:31 PM PST US From: richard@riley.net Subject: AeroElectric-List: FS: MX20 --> AeroElectric-List message posted by: richard@riley.net I have a brand new, never unpacked, fully factory warranteed UPSAT MX20 that I'm selling for under dealer cost. Retail $7300, my price, $5100. I can also do a deep discount on a new GX 60 to drive it.