---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 06/12/08: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:46 AM - Re: Drilling Switch holes in aluminum? (n801bh@netzero.com) 2. 08:12 AM - Re: Re: Bridge Diodes use (Ernest Christley) 3. 09:00 AM - Re: Creation Of Wiring Diagram (tsts4) 4. 09:31 AM - Re: Re: Bridge Diodes use (Richard Dudley) 5. 03:39 PM - Re: Loran to VHF (Robert L. Nuckolls, III) 6. 04:18 PM - Re: Re: Bridge Diodes use (Robert L. Nuckolls, III) 7. 04:25 PM - Re: Re: Bridge Diodes use (Robert L. Nuckolls, III) 8. 04:36 PM - Re: Problem with Turbo CAD (Robert L. Nuckolls, III) 9. 04:54 PM - Re: Re: Bridge Diodes use (Matt Prather) 10. 06:23 PM - Re: Boost pumps (Joe) 11. 07:10 PM - DB25 tap adapter (Alan Adamson) 12. 07:42 PM - Re: Loran to VHF (B Tomm) 13. 08:12 PM - Re: Boost pumps (Dennis Jones) ________________________________ Message 1 _____________________________________ Time: 06:46:36 AM PST US From: "n801bh@netzero.com" Subject: Re: AeroElectric-List: Drilling Switch holes in aluminum? I also used a unibit.. Worked perfect for me. do not archive Ben Haas N801BH www.haaspowerair.com -- Kevin Horton wrote: On 11 Jun 2008, at 14:38, Ron Shannon wrote:On Wed, Jun 11, 2008 at 10:0 0 AM, Robert Feldtman wrote: wouldn't the 1/2 inch do? 15/32 is only slightly smaller, I bet it would work fine. .... Actually, the S700 series switches are already a bit loose in the mfgr.' s recommended 15/32" hole. Consequently, I would prefer to follow the ve ndor's recommendation and not mount them even more loosely. I used a Unibit step drill that had a 15/32 step. It did an excellent j ob - the switches fit very well. --Kevin HortonRV-8 (FInal Assembly)Ottawa, Canadahttp://www.kilohotel.co m/rv8 ======================== ======================== ======================== ======================== ======================== ======================== ======= ____________________________________________________________ Click now and invest wisely with these mutual fund resources! http://thirdpartyoffers.netzero.net/TGL2241/fc/Ioyw6i4ujza1iQQNV1n6oUjE5 deQtqoqDvjAfNa0rd05n3Qkv7H0jX/ ________________________________ Message 2 _____________________________________ Time: 08:12:39 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Re: Bridge Diodes use ptrotter@optonline.net wrote: > Yes, you can parallel the diode with a switch as a direct E-bus feed, but I don't want that voltage drop in normal operations either. > Why? I can understand you being bothered by the idea that something is just wasting power. Great. Fix that. That's what's beautiful about getting away from the FAA that would dictate what you can do. But after swapping out the FWB, don't bother giving a big sigh of relief and proclaiming that you just saved someone's life. All you did was scratch and itch, not cure world hunger. > Just because something has worked well for years does not mean that newer products that perform better are not available today. While the FWB is a nice package for mounting and wiring, it is no longer the best product for the application. If we were to continue to think this way, there would be no innovation and we would all be running steam gauges rather than EFIS systems. In all these discussions, I have never seen anybody make a statement that a plain diode is the best solution, only that it is adequate. Adequate in not good enough for me if a better solution is available. It is somewhat contradictory to install a 21st centrury flight instument system connected to a 1950's technology power system. > You'll need to define "best". The BEST I know how to do would be to save up $10K to have someone else paint my airplane. That would be the BEST. But it ain't gonna happen. I'll be painting it in my garage, with my $50 Harbor Freight HVLP gun, and with chemicals that are not guaranteed to kill my family and neighbors. That is adequate. Sufficient. Gets the job done. Then I'll go flying. (The $50 gun did an excellent job with the Polyfiber chemicals on my airplanes belly and control surfaces, BTW. The only problem was the MEK destroyed the can's seal.) The requirement for change isn't to prove the old method inadequate. The requirement is to prove the new method superior. "Superior" includes not just minor esoteric operating benefits, but acquisition, build complexity, cost, and whatever else someone might be concerned about. I say the EFIS is better because it is lighter, more reliable, easier to build into the plane, easier to source (one piece vs several) and cheaper. I'll be buying a Dynon very soon now (I've installed their mounting fixture, but I've been waiting till the last minute to buy the actual unit). Whether you agree with my analysis or not, I have defined what I consider to be "better". OTOH, I see no measurable benefit to the Schottky diode for this application. The argument is that it conserves power in use, but that power consumption doesn't rank worthy of merit. I also see having to purchase from a seperate source being an additional headache. I see the more complex build requirements being more of a headache. While the extra expense is marginal, it is also pointless. The Schottky diode does not meet my criteria for being better. If the Schottky were widely available in a package like the FWB it might be different, but with the information I have I declare the FWB is most definitely the best product for the application. If you feel the arguments presented for Schottky diodes make it a better solution, GREAT!! Go buy you a bagful if it suits you. But realize that many of us don't see it that way, and declaring that we should consider doubling our life insurance is fearmongering, disingenuous bull. There are NO safety issues with the FWB solution. ________________________________ Message 3 _____________________________________ Time: 09:00:53 AM PST US Subject: AeroElectric-List: Re: Creation Of Wiring Diagram From: "tsts4" I used Excel. -------- Todd Stovall 728TT (reserved) RV-10 Empacone Read this topic online here: http://forums.matronics.com/viewtopic.php?p=187601#187601 Attachments: http://forums.matronics.com//files/wiring_diagram_205.xls ________________________________ Message 4 _____________________________________ Time: 09:31:37 AM PST US From: "Richard Dudley" Subject: Re: AeroElectric-List: Re: Bridge Diodes use Hear Hear!! Ernest. There is an old expression: "Perfection is the enemy of good enough". Though one man's perfection is another's absurd extravagance. Regards, Richard Dudley RV-6A flying with Z-11 ----- Original Message ----- From: "Ernest Christley" Sent: Thursday, June 12, 2008 11:08 AM Subject: Re: AeroElectric-List: Re: Bridge Diodes use > > > ptrotter@optonline.net wrote: >> Yes, you can parallel the diode with a switch as a direct E-bus feed, >> but I don't want that voltage drop in normal operations either. >> > Why? I can understand you being bothered by the idea that something is > just wasting power. Great. Fix that. That's what's beautiful about > getting away from the FAA that would dictate what you can do. But after > swapping out the FWB, don't bother giving a big sigh of relief and > proclaiming that you just saved someone's life. All you did was scratch > and itch, not cure world hunger. >> Just because something has worked well for years does not mean that newer >> products that perform better are not available today. While the FWB is a >> nice package for mounting and wiring, it is no longer the best product >> for the application. If we were to continue to think this way, there >> would be no innovation and we would all be running steam gauges rather >> than EFIS systems. In all these discussions, I have never seen anybody >> make a statement that a plain diode is the best solution, only that it is >> adequate. Adequate in not good enough for me if a better solution is >> available. It is somewhat contradictory to install a 21st centrury >> flight instument system connected to a 1950's technology power system. >> > You'll need to define "best". The BEST I know how to do would be to save > up $10K to have someone else paint my airplane. That would be the BEST. > But it ain't gonna happen. I'll be painting it in my garage, with my $50 > Harbor Freight HVLP gun, and with chemicals that are not guaranteed to > kill my family and neighbors. That is adequate. Sufficient. Gets the > job done. Then I'll go flying. (The $50 gun did an excellent job with > the Polyfiber chemicals on my airplanes belly and control surfaces, BTW. > The only problem was the MEK destroyed the can's seal.) > > The requirement for change isn't to prove the old method inadequate. The > requirement is to prove the new method superior. "Superior" includes not > just minor esoteric operating benefits, but acquisition, build complexity, > cost, and whatever else someone might be concerned about. I say the EFIS > is better because it is lighter, more reliable, easier to build into the > plane, easier to source (one piece vs several) and cheaper. I'll be > buying a Dynon very soon now (I've installed their mounting fixture, but > I've been waiting till the last minute to buy the actual unit). Whether > you agree with my analysis or not, I have defined what I consider to be > "better". > > OTOH, I see no measurable benefit to the Schottky diode for this > application. The argument is that it conserves power in use, but that > power consumption doesn't rank worthy of merit. I also see having to > purchase from a seperate source being an additional headache. I see the > more complex build requirements being more of a headache. While the extra > expense is marginal, it is also pointless. The Schottky diode does not > meet my criteria for being better. If the Schottky were widely available > in a package like the FWB it might be different, but with the information > I have I declare the FWB is most definitely the best product for the > application. > > If you feel the arguments presented for Schottky diodes make it a better > solution, GREAT!! Go buy you a bagful if it suits you. But realize that > many of us don't see it that way, and declaring that we should consider > doubling our life insurance is fearmongering, disingenuous bull. There > are NO safety issues with the FWB solution. > > > ________________________________ Message 5 _____________________________________ Time: 03:39:17 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Loran to VHF At 09:12 AM 6/11/2008 -0700, you wrote: > > >Bob, > >Can a Loran antenna (CI 121 SP) be converted/trimmed into a VHF Comm. >antenna? > >Thanks Probably not. LORAN is a low frequency (100 KHz) facility that could NEVER benefit from a tuned antenna on a vehicle. Just too long. So these antennas tend to be like those used on another low frequency (550 to 1700 KHz) system, AM entertainment radio. The "coaxial" cable is really a very low capacitance, shielded cable designed to minimially load a short, e-field antenna that delivers a relatively weak signal due to it's Lilliputian dimensions. Certainly you can adjust the length of the LORAN antenna to make it resonant at VHF comm frequencies but the coaxial cable associated with the antenna may very well be the low-capacity wire I described. My sense is that you'll spend so much time modifying the antenna and then proving that you did a good thing that you're $time$ ahead just to put a real VHF antenna in from the get-go. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 6 _____________________________________ Time: 04:18:08 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Bridge Diodes use At 06:28 PM 6/10/2008 +0200, you wrote: >> >On B & C Diode Installation sheet they state that "Heatsink must >> dissipate 0.6 X Amps = Watts. Example For 20 Amp Essential Bus, 0.6 X 20 >> = 12 Watt Heatsink". > >In my experience, I have never come across a 12W heatsink. Nor a 1W or >1000W heatsink. > >A heatsink is chosen appropriate to the temperature rise above ambient the >casing of the device can tolerate, or what the spec-sheet says. A single >machined-bolt head can dissipate 12W without any additional cooling, >however only when it reaches 200 degrees C (thumbsuck). If you can only >tolerate a 1degC increase in temperature, the heatsink required to >dissipate 12W will be the size of a large desk. > >So, a specsheet specifies the heatsinking requirements in [degrees above >ambient]/[Watt], or specifies the maximum allowable temperature. So >consider an ambient of 23degC, a maximum of 100degC, and we have >calculated that the device will need to dissipate 10W. That gives us a >requirement for a 7.7deg/Watt heatsink, which can be ordered accordingly. > >I understand the calculations relating to dissipation of heat, and IIRC a >Schottky diode, with a forward bias voltage of 0.2V rather than the >0.6~0.7V of a regular diode, dissipates 1/3 the energy for a given >current. However, there are always other considerations that have not been >touched in this discussion (such as thermal robustness, vibration >tolerance, ease of mounting), some of which are the same for both Schottky >diodes and for normal ones, and others which will draw very clear lines in >the sand precluding one or both from certain applications. Very good! You have nailed the physics of heat-sink sizing. Any size heatsink will dissipate the energies of ANY size heat source . . . the question to be asked and answered is "hot hot does it get" over and above ambient while being stoked at that energy level -AND- environmental temperature. B&C's advice was ill worded but I don't work for them any more. At the same time, I was hoping someone to rise to the task of illuminating the physics of the matter. As I write these words, there's a Schottky device in the chamber getting it's thermal portrait taken on the same heatsink that gave us a portrait of a common power rectifier earlier this week. I'll have comparable DATA to share in the not too distant future. My hat's off to you sir. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 7 _____________________________________ Time: 04:25:03 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Bridge Diodes use At 06:05 PM 6/10/2008 -0600, you wrote: > >Eric, > >Am loath to get between you and Bob when discussing electrons but don't >understand what you said about bridge diode heat dissipation. If one >diode is running 20 amps with a forward voltage of 0.6 then it generates >0.6 x 20 = 12 watts of heat. >If two diodes in parallel are carrying the same 20 amps then the current >is split between the two diodes, with each having more or less half the >load with a total of 20 amps between them. So each diode is generating >about half of 12 watts with a total generation of still only 12 watts not 24. > >What am I missing? You'll never be 'stuck' between us my friend. Your question is very much on point because until a posting pointed out a little detail about "thermal resistance" ratings of heat dissipation systems, there was no way that anyone should be expected understand what was correct and/or incorrect about any of the advice. Know that a Bob's Shop Notes is being crafted with real data that will make the physics clear and give you the tools with which to make a design decision about your system. There is nothing inherently evil or good about either device. Both technologies have and are producing satisfactory performance when used in a manner that does not violate their performance envelopes. The smoke and mirrors will be dealt with. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 8 _____________________________________ Time: 04:36:45 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Problem with Turbo CAD At 07:07 PM 6/10/2008 -0500, you wrote: > >Bob, > >I bought one of the "cheap" copies of Turbo CAD 10.2 and it opens the Zxx >files just fine. Problem is, I can't seem to find any of the tutorials on >their web site. I suspect they pull them after some number of newer >versions are released. I'm sure a policy designed to sell more upgrades. > >I recently took a little intro CAD course at the local junior college but >they were using AutoCAD 2008. Little similarity I am afraid (no command >line in TC) so was looking for some way to learn TC without printing out the >400 plus page pdf document on the CDROM. > >Amy suggestions on learning TC 10.2 other than to just tough it out? > >At any rate, thanks for all the wonderful information and drawings. >Couldn't do this wiring thing without it. Go to a Borders or similar bookstore and look through the technical how-to books. It will be a "Turbo-CAD for Dummies" by a third party author. Then search for instructions on the use of these commands: AR, *ARRAY B, *BLOCK WB, *WRITEBLOCK BR, *BREAK CI, *CIRCLE C, *CHANGE CH, *CHAMFER CO, *COPY D, *DIMSTYLE DI, *DIST DO, *DONUT DT, *DTEXT E, *ERASE ED, *DDEDIT EL, *ELLIPSE XT, *EXTEND EXIT, *QUIT F, *FILLET H, *HATCH I, *INSERT IP, *ISOPLANE L, *LINE LA, *LAYER LI, *LIST LT, *LINETYPE M, *MOVE MI, *MIRROR OF, *OFFSET OS, *OSNAP P, *PAN PE, *PEDIT PL, *PLINE PG, *POLYGON P, *PAN R, *REDRAW RG, *REGEN RT, *RECTANGLE REN *RENAME RO, *ROTATE S, *STRETCH SC, *SCALE SCR, *SCRIPT T, *TRIM V, *VIEW XP, *EXPLODE Z, *ZOOM This is a list of my one and two-stroke command contractions for AutoCAD. This list covers 95% of everything I ask AutoCAD to do in my almost daily use for 20+ years. AutoCAD (and TurboCAD) will do MUCH more but these activities let me produce all of the illustrations for the 'Connection (and for my clients). Get up to speed on the same functions in TurboCAD and you can do just about everything I do. Some TurboCAD packages come with tutorials. See: http://www.cadandgraphics.com/tcdlx15.html?gclid=CP6Bm7iI8JMCFQabnAodTgNIWQ Here are some turbocad tutorials. Perhaps not "up to date" with your version but the list I gave you above is the most rudimenatry of CAD functions . . . probably good for any version mix of books and software. http://tinyurl.com/4lssx3 http://tinyurl.com/3ueqet Bob . . . ________________________________ Message 9 _____________________________________ Time: 04:54:25 PM PST US Subject: Re: AeroElectric-List: Re: Bridge Diodes use From: "Matt Prather" One final thought about this.. If we keep our E-buses on a diet, the Vf will be lower, and the heat loss through whatever diode you choose will be less. These obese E-buses are killing us!! Hah. :) Matt- > > > >> I think this is the point that nobody was making.. Vf is not the knee >> voltage. Bob White sent me a link to a Fairchild datasheet that showed >> the I-V curve for one of their devices. Forward biasing conduction got >> going around 0.6V - 0.7V, but at the rated current the voltage drop was >> up around 1.0V - 1.1V. Eric, had you mentioned this early in the >> discussion, I think we could have avoided a bunch of this churning... >> http://www.fairchildsemi.com/ds/1N/1N4007.pdf >> I still haven't seen where B&C stated that the voltage drop would be >> half >> by running in parallel.. Certainly the voltage drop is reduced by >> running >> the diode lower on the I-V curve for a given buss current.. But not by >> half obviously. Maybe an estimate would be halfway between the published >> Vf and the knee voltage. >> Regards, Matt > > > Matt, et al. > > See: http://www.bandc.biz/Diode_Installation.pdf > > I don't claim that B & C ever stated that diodes' Vf could be summed like > parallel mosfets (etc.). But I saw the 0.6 Vf on their schematic as a very > suspicious indicator that somebody thought so, and that this should be > attended to. > > Yes, Matt, maybe I should have clarified some points earlier. But it was > 100 degrees yesterday, fer chis'sakes. Thanks for your sage input. > (Ahem...which you should have said earlier....) > > -------- > 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=187390#187390 > > ________________________________ Message 10 ____________________________________ Time: 06:23:52 PM PST US From: "Joe" Subject: Re: AeroElectric-List: Boost pumps Jonsey, How many fuel pumps do you have and where are they located? Are there two batteries with alternate feed paths to the fuel pump(s)? Is there an engine driven fuel pump? Or is it gravity fed with an electric boost pump? Joe G. ________________________________ Message 11 ____________________________________ Time: 07:10:42 PM PST US From: "Alan Adamson" Subject: AeroElectric-List: DB25 tap adapter All, I had the need to create a simple Tap for a DB25 connector. I decided to try out a new board house and have lots available. These make a great way to Y into anything that uses a DB25 connector. E.g.GPS, or other signals. They are very simple to use, you just unconnect your existing db25 and plug this in-between. Screws and nuts can be picked up easily at Frys or RS. I will supply them with connectors - either 2 males, 2 females or 1 of each - your choice. The board presses between the solder cups and then you solder the connectors to the little board. The board has a tap point for each pin number and it's only .5 inches wide. The entire connector is only 1.5" wide when assembled. The via's will take up to 20ga wire and should support anything that we might need. I'll sell these for $5 each or $8 for a pair (2 full sets) + $2 S/H (usps) to anywhere in the US (international if needed will be actual postage or a negotiated rate). If interested, drop me a note with qty, gender, and I'll provide paypal information for purchase and get them shipped right out. I've attached pictures for your reference, if those don't go thru, you can see them here. http://www.highrf.com/Rockets/db25/DSCN2109_edited-2.jpg http://www.highrf.com/Rockets/db25/DSCN2111_edited-2.jpg http://www.highrf.com/Rockets/db25/DSCN2114_edited-1.jpg my email is adamson (underscore) alan at hotmail dot com As a side note, I'm tempted to do the same for db9 and db15 connectors... we'll see, I suppose if there is enough demand, I could do the big db connectors too (37 pin is it?). Alan ________________________________ Message 12 ____________________________________ Time: 07:42:01 PM PST US From: "B Tomm" Subject: RE: AeroElectric-List: Loran to VHF Thanks Bob, I was considering shortening (tuning) a used Loran antenna for use with a VHF aircraft radio as a base station for a local airshow coming up. The regular 50 ohm coax would be used to feed it. Bevan -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, June 12, 2008 3:35 PM Subject: Re: AeroElectric-List: Loran to VHF --> At 09:12 AM 6/11/2008 -0700, you wrote: >--> > > >Bob, > >Can a Loran antenna (CI 121 SP) be converted/trimmed into a VHF Comm. >antenna? > >Thanks Probably not. LORAN is a low frequency (100 KHz) facility that could NEVER benefit from a tuned antenna on a vehicle. Just too long. So these antennas tend to be like those used on another low frequency (550 to 1700 KHz) system, AM entertainment radio. The "coaxial" cable is really a very low capacitance, shielded cable designed to minimially load a short, e-field antenna that delivers a relatively weak signal due to it's Lilliputian dimensions. Certainly you can adjust the length of the LORAN antenna to make it resonant at VHF comm frequencies but the coaxial cable associated with the antenna may very well be the low-capacity wire I described. My sense is that you'll spend so much time modifying the antenna and then proving that you did a good thing that you're $time$ ahead just to put a real VHF antenna in from the get-go. Bob . . . ----------------------------------------) ( . . . a long habit of not thinking ) ( a thing wrong, gives it a superficial ) ( appearance of being right . . . ) ( ) ( -Thomas Paine 1776- ) ---------------------------------------- ________________________________ Message 13 ____________________________________ Time: 08:12:54 PM PST US From: "Dennis Jones" Subject: Re: AeroElectric-List: Boost pumps One electric backup pump, one battery with one feed. Pump on pump off no solenoid. Jonsey ----- Original Message ----- From: Joe To: aeroelectric-list@matronics.com Sent: Thursday, June 12, 2008 8:17 PM Subject: Re: AeroElectric-List: Boost pumps Jonsey, How many fuel pumps do you have and where are they located? Are there two batteries with alternate feed paths to the fuel pump(s)? Is there an engine driven fuel pump? Or is it gravity fed with an electric boost pump? Joe G. ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.