---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 06/11/08: 23 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:29 AM - Re: Re: Bridge Diodes use (The Kuffels) 2. 07:07 AM - Re: Re: Bridge Diodes use (Bob White) 3. 08:15 AM - Re: Bridge Diodes use (Eric M. Jones) 4. 09:01 AM - Re: Starting the REAL electrical work on my 601XL (Gig Giacona) 5. 09:17 AM - Loran to VHF (B Tomm) 6. 09:32 AM - Re: Re: Starting the REAL electrical work on my 601XL (Hinde, Frank George (Corvallis)) 7. 09:41 AM - Re: Re: Bridge Diodes use (Matt Prather) 8. 10:06 AM - Re: Drilling Switch holes in aluminum? (Robert Feldtman) 9. 10:25 AM - Re: Bridge Diodes use (Eric M. Jones) 10. 10:35 AM - Re: Re: Starting the REAL electrical work on my 601XL (Ken) 11. 10:41 AM - Re: Re: Bridge Diodes use (Ernest Christley) 12. 11:06 AM - Re: Re: Bridge Diodes use (Matt Prather) 13. 11:29 AM - Creation Of Wiring Diagram (Dave VanLanen) 14. 11:42 AM - Re: Drilling Switch holes in aluminum? (Ron Shannon) 15. 11:42 AM - "Dead horse" (Roger & Jean) 16. 11:57 AM - Re: Creation Of Wiring Diagram (Ernest Christley) 17. 12:27 PM - Re: Creation Of Wiring Diagram (LarryMcFarland) 18. 12:39 PM - Re: Creation Of Wiring Diagram (Vernon Little) 19. 12:58 PM - Re: Re: Bridge Diodes use (ptrotter@optonline.net) 20. 01:00 PM - Re: Creation Of Wiring Diagram (Hinde, Frank George (Corvallis)) 21. 02:34 PM - Re: Re: Bridge Diodes use (Richard Tasker) 22. 05:40 PM - Re: Drilling Switch holes in aluminum? (Kevin Horton) 23. 09:06 PM - Boost pumps (Dennis Jones) ________________________________ Message 1 _____________________________________ Time: 01:29:36 AM PST US From: The Kuffels Subject: Re: AeroElectric-List: Re: Bridge Diodes use Eric, Still don't follow you. I said: << 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 .. each diode is generating about half of 12 watts with a total generation of still only 12 watts not 24. >> You said: << If either one or two or a hundred conventional diodes is sharing the load, they still dissipate Vf X A. >> Agreed. But each diode is carrying a smaller fraction of the same total amps so the total example heat generated remains 12 watts. Put algebraically: Let Vf x A = 12 Watts Let 3 diodes in parallel carry the same total current so Vf1 = Vf2 = Vf3 = Vf a1 + a2 + a3 = A Then (Vf1 x a1) + (Vf2 x a2) + (Vf3 x a3) = Vf x (a1 + a2 + a3) = Vf x A = 12 watts << Vf is not reduced by putting parts in parallel. >> Never said it did reduce Vf. (I've always used 0.7V for silicon and 0.3V for germanium in my minimal design work but a Vf of 0.6V is close enough also for this discussion.) I did say it reduced the current carried by each individual part. << but the package is what we bolt to the heat sink. >> But the package in your example is still only generating 12 watts of heat, not 24. See below. << claim that a B & C FWB, when wired so that two diodes are parallel, would have a Vf of 0.6. It does not; the Vf is often 1.2 maybe, and someone incorrectly assumed that the diodes being in parallel made the Vf sum 0.6. The very best conventional FWB diodes are 0.9Vf at 10A for each diode (you can't buy these at Radio Shack), so it dissipates (2X0.9X10A=) 18W VERY BEST CASE., and 24W worst case if the diodes are Vf=1.2. >> As Matt says, a Vf of 1.2 is only true when the FWB is wired up as a full wave rectifier. Then there are indeed two diodes working in *series* for each half cycle with a Vf of about 1.3V. Perhaps, you might be referring to the fact the forward voltage drop across a single diode increases from the turn-on voltage value with increasing current. This can get above 1 volt at high currents. But your use of 0.6V clearly made the discussion at the turn-on voltage point not the Vf at high current. The situation is the same whether we talk about Vf at turn-on current or Vf at high current as long as we remain consistent. And as an aside, putting diodes in parallel brings us lower on the current scale for each device and closer to its turn-on voltage. In other words, putting diodes in parallel lowers (slightly) the total heat generated for the same total current. In parallel, each diode still has it's original Vf and since they are in parallel they don't add voltages. Whether there is 1 or 100 diodes in the package, they are still only carrying the original example 20 amps total with a voltage drop between the input terminal and the output terminal of one Vf since there is only one diode drop between the terminals no matter how many diodes are wired in parallel in between. << FWB ... You could make your own, but it's easier to abandon the concept entirely. >> Not claiming to be a FWB fan for this application. Just don't see how running 20 amps total across one diode drop doubles the heat generated when another diode is added to share the same current. Under this logic, 8 diodes in parallel would generate 96 watts, 16 would generate 192 watts, etc. which is obviously not what you mean to imply. Basically, do not see how wiring diodes in parallel causes their forward voltage drops to add together as you seem to be saying. Tom, AL7AU ________________________________ Message 2 _____________________________________ Time: 07:07:24 AM PST US From: Bob White Subject: Re: AeroElectric-List: Re: Bridge Diodes use If you look up single silicon diodes in the 10 A to 20 A current rating on Mouser or Digikey, you will find the Vf is 1.1 Volts or higher for most of them. For example, a 1N3210 (a 15 A unit) is 1.5 V at 15 amps. Look up a 1N4007 rated at 1 amp. Vf is 1.1V. Eric is right on the money on this. He is just saying you can't use 0.6 Volts for Vf because you have two 1.2 volt devices in parallel. Bob W. On Wed, 11 Jun 2008 02:25:10 -0600 The Kuffels wrote: > > Eric, > > Still don't follow you. > > I said: > << 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 .. each diode is generating about half of > 12 watts with a total generation of still only 12 watts not 24. >> > > You said: > << If either one or two or a hundred conventional diodes is > sharing the load, they still dissipate Vf X A. >> > > Agreed. But each diode is carrying a smaller fraction of the > same total amps so the total example heat generated remains 12 > watts. Put algebraically: > > Let Vf x A = 12 Watts > Let 3 diodes in parallel carry the same total current so > Vf1 = Vf2 = Vf3 = Vf > a1 + a2 + a3 = A > Then > (Vf1 x a1) + (Vf2 x a2) + (Vf3 x a3) = Vf x (a1 + a2 + a3) > = Vf x A = 12 watts > > << Vf is not reduced by putting parts in parallel. >> > > Never said it did reduce Vf. (I've always used 0.7V for silicon > and 0.3V for germanium in my minimal design work but a Vf of 0.6V > is close enough also for this discussion.) I did say it reduced > the current carried by each individual part. > > << but the package is what we bolt to the heat sink. >> > > But the package in your example is still only generating 12 watts > of heat, not 24. See below. > > << claim that a B & C FWB, when wired so that two diodes are > parallel, would have a Vf of 0.6. It does not; the Vf is often > 1.2 maybe, and someone incorrectly assumed that the diodes being > in parallel made the Vf sum 0.6. The very best conventional FWB > diodes are 0.9Vf at 10A for each diode (you can't buy these at > Radio Shack), so it dissipates (2X0.9X10A=) 18W VERY BEST CASE., > and 24W worst case if the diodes are Vf=1.2. >> > > As Matt says, a Vf of 1.2 is only true when the FWB is wired up > as a full wave rectifier. Then there are indeed two diodes > working in *series* for each half cycle with a Vf of about 1.3V. > > Perhaps, you might be referring to the fact the forward voltage > drop across a single diode increases from the turn-on voltage > value with increasing current. This can get above 1 volt at high > currents. But your use of 0.6V clearly made the discussion at > the turn-on voltage point not the Vf at high current. The > situation is the same whether we talk about Vf at turn-on current > or Vf at high current as long as we remain consistent. > > And as an aside, putting diodes in parallel brings us lower on > the current scale for each device and closer to its turn-on > voltage. In other words, putting diodes in parallel lowers > (slightly) the total heat generated for the same total current. > > In parallel, each diode still has it's original Vf and since they > are in parallel they don't add voltages. Whether there is 1 or > 100 diodes in the package, they are still only carrying the > original example 20 amps total with a voltage drop between the > input terminal and the output terminal of one Vf since there is > only one diode drop between the terminals no matter how many > diodes are wired in parallel in between. > > << FWB ... You could make your own, but it's easier to abandon > the concept entirely. >> > > Not claiming to be a FWB fan for this application. Just don't > see how running 20 amps total across one diode drop doubles the > heat generated when another diode is added to share the same > current. Under this logic, 8 diodes in parallel would generate > 96 watts, 16 would generate 192 watts, etc. which is obviously > not what you mean to imply. > > Basically, do not see how wiring diodes in parallel causes their > forward voltage drops to add together as you seem to be saying. > > Tom, AL7AU > -- N93BD - Rotary Powered BD-4 - http://www.bob-white.com 3.8 Hours Total Time and holding Cables for your rotary installation - http://roblinstores.com/cables/ ________________________________ Message 3 _____________________________________ Time: 08:15:08 AM PST US Subject: AeroElectric-List: Re: Bridge Diodes use From: "Eric M. Jones" > If you look up single silicon diodes in the 10 A to 20 A current rating > on Mouser or Digikey, you will find the Vf is 1.1 Volts or higher for > most of them. For example, a 1N3210 (a 15 A unit) is 1.5 V at 15 amps. > Look up a 1N4007 rated at 1 amp. Vf is 1.1V. Eric is right on the > money on this. He is just saying you can't use 0.6 Volts for Vf because > you have two 1.2 volt devices in parallel. > Bob W. Yeah...What HE said...! Thanks, Bob White. I can't in any reasonable time answer some previous posts, but there are a couple issues that seem to confuse some people: The FWB when used as Bob N. and B & C recommends uses two diodes in parallel. The watts dissipated by the part at 20A is WORST CASE 1.2 x 20=24Watts. The Vf of a diode is a strongly influenced by current. A diode can be 0.7 Vf at zero Amps, and 1.0 Vf at 10A and 1.2 Vf at 12.5. For this you have to read the data sheet. What?! Radio Shack doesn't supply one?! Then just guess and hope you're right. Double up on the life insurance, too. "In times of rapid change, experience could be your worst enemy." --Jean Paul Getty -------- 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=187361#187361 ________________________________ Message 4 _____________________________________ Time: 09:01:29 AM PST US Subject: AeroElectric-List: Re: Starting the REAL electrical work on my 601XL From: "Gig Giacona" No, you are right that is a single point of failure and I'm not blowing you off on the issue but is has been discussed to death in other forums and it has become the standard method for the William Wynne Corvair conversion. Very quickly the theory is in the case of an engine failure there is generally going to be only to failure modes you can do anything about in the cockpit. One is the fuel system and one is the ignition system. With the single switch design you put in a fresh fuel pump and a fresh ignition system online. We do try to use the best Mil-Spec switch we can find to at least reduce the chance. The theory goes on that multiple switches introduces multiple single points of failure and while we hate them they are in every plane that ever flew and it also introduces switchology issues that have a greater chance of pilot error than does the single switch. I agree the more equipment fault resistant method would be 4 switches one for each pump and one for each ignition. But in the case of an engine outage the pilot then has to run through multiple switch settings to figure out the problem. It all comes down to the guy that designed the conversion came up with this method and there are a bunch of planes flying with it. I'm not tempted at this point to change it. [quote="mprather(at)spro.net] It's possible I don't clearly understand how you'll be wiring the fuel pumps and ignition system(s).. But it sounds like you are saying that there will be a single switch controlling everything. If so, I believe this switch represents a single point of failure, which is generally undesirable for flight critical electrical items - at least when it comes to switches... If the switch falls apart, the engine could stop running(?). Matt[/quote] -------- W.R. "Gig" Giacona 601XL Under Construction See my progress at www.peoamerica.net/N601WR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=187372#187372 ________________________________ Message 5 _____________________________________ Time: 09:17:11 AM PST US From: "B Tomm" Subject: AeroElectric-List: Loran to VHF Bob, Can a Loran antenna (CI 121 SP) be converted/trimmed into a VHF Comm. antenna? Thanks Bevan ________________________________ Message 6 _____________________________________ Time: 09:32:16 AM PST US From: "Hinde, Frank George (Corvallis)" Subject: RE: AeroElectric-List: Re: Starting the REAL electrical work on my 601XL It also very easy to have 4 swithes in a prominent location as I do on the RV (electric fuel pumps only) and did have on my 601HDS. If the engine quits all 4 get banged upwards regardless... As to adding points of failure this is simply untrue, you have a separate fuse, wiring, switch for each discreet component...Its a fault tolerant design. I understand that you are comfortable with the system and if that your chocie go with it..William is a sharp guy but fuel pumps halfway up on the engine side of the firewall (at least it was that way in the last picture I saw) is a vapour lock prone design and single POF electrical system are two big no-nos for me. Frank 601 HDS 500 hours RV7a (IO360) all electric -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Gig Giacona Sent: Wednesday, June 11, 2008 8:57 AM Subject: AeroElectric-List: Re: Starting the REAL electrical work on my 601XL --> No, you are right that is a single point of failure and I'm not blowing you off on the issue but is has been discussed to death in other forums and it has become the standard method for the William Wynne Corvair conversion. Very quickly the theory is in the case of an engine failure there is generally going to be only to failure modes you can do anything about in the cockpit. One is the fuel system and one is the ignition system. With the single switch design you put in a fresh fuel pump and a fresh ignition system online. We do try to use the best Mil-Spec switch we can find to at least reduce the chance. The theory goes on that multiple switches introduces multiple single points of failure and while we hate them they are in every plane that ever flew and it also introduces switchology issues that have a greater chance of pilot error than does the single switch. I agree the more equipment fault resistant method would be 4 switches one for each pump and one for each ignition. But in the case of an engine outage the pilot then has to run through multiple switch settings to figure out the problem. It all comes down to the guy that designed the conversion came up with this method and there are a bunch of planes flying with it. I'm not tempted at this point to change it. [quote="mprather(at)spro.net] It's possible I don't clearly understand how you'll be wiring the fuel pumps and ignition system(s).. But it sounds like you are saying that there will be a single switch controlling everything. If so, I believe this switch represents a single point of failure, which is generally undesirable for flight critical electrical items - at least when it comes to switches... If the switch falls apart, the engine could stop running(?). Matt[/quote] -------- W.R. "Gig" Giacona 601XL Under Construction See my progress at www.peoamerica.net/N601WR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=187372#187372 ________________________________ Message 7 _____________________________________ Time: 09:41:56 AM PST US Subject: Re: AeroElectric-List: Re: Bridge Diodes use From: "Matt Prather" 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 > The Vf of a diode is a strongly influenced by current. A diode can be 0.7 > Vf at zero Amps, and 1.0 Vf at 10A and 1.2 Vf at 12.5. For this you have to read the data sheet. What?! Radio Shack doesn't supply one?! Then just > guess and hope you're right. Double up on the life insurance, too. > > > "In times of rapid change, experience could be your worst enemy." > --Jean Paul Getty > > -------- > 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=187361#187361 > > ________________________________ Message 8 _____________________________________ Time: 10:06:46 AM PST US From: "Robert Feldtman" Subject: Re: AeroElectric-List: Drilling Switch holes in aluminum? wouldn't the 1/2 inch do? 15/32 is only slightly smaller, I bet it would work fine. agree with dale's suggestion bobf On 6/10/08, Ron Shannon wrote: > > > On Tue, Jun 10, 2008 at 3:51 PM, Dale Rogers wrote: > >> >> Ron, >> >> Wrong kind of "punch". Take a lot at the Harbor Freight # 91201 punch >> set: >> >> [ http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91201] >> >> One drills a center/pilot hole for the through-bolt, which pulls the two >> halves of the punch together through the panel. No throat size to worry >> about. >> >> Dale R. >> COZY MkIV #0497 >> Ch. 13 > > > Yes, of course, but... still no 15/32" for the S700's. > > Ron > > ________________________________ Message 9 _____________________________________ Time: 10:25:55 AM PST US Subject: AeroElectric-List: Re: Bridge Diodes use From: "Eric M. Jones" > 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: 10:35:01 AM PST US From: Ken Subject: Re: AeroElectric-List: Re: Starting the REAL electrical work on my 601XL Gig I agree with you, keep it simple for single ignition and fuel injection. A thought for anyone who has not followed such discussions though is the case of systems that don't always fail passive. A real life example would be that the the primary ignition system starts sending out erratically timed sparks. My reflex action is to turn on the second ignition and fuel pump if the engine hickups in any way. All switches on. Time permitting, if that does not fix things, I next might try turning off the primary ignition. There are cases where that restored the engine. Can't do that though if the primary ignition is on the same switch as single fuel injection. Ken Gig Giacona wrote: > > > No, you are right that is a single point of failure and I'm not > blowing you off on the issue but is has been discussed to death in > other forums and it has become the standard method for the William > Wynne Corvair conversion. Very quickly the theory is in the case of > an engine failure there is generally going to be only to failure > modes you can do anything about in the cockpit. One is the fuel > system and one is the ignition system. With the single switch design > you put in a fresh fuel pump and a fresh ignition system online. We > do try to use the best Mil-Spec switch we can find to at least reduce > the chance. The theory goes on that multiple switches introduces > multiple single points of failure and while we hate them they are in > every plane that ever flew and it also introduces switchology issues > that have a greater chance of pilot error than does the single > switch. > > I agree the more equipment fault resistant method would be 4 switches > one for each pump and one for each ignition. But in the case of an > engine outage the pilot then has to run through multiple switch > settings to figure out the problem. > > It all comes down to the guy that designed the conversion came up > with this method and there are a bunch of planes flying with it. I'm > not tempted at this point to change it. > > > > > [quote="mprather(at)spro.net] > > It's possible I don't clearly understand how you'll be wiring the > fuel pumps and ignition system(s).. But it sounds like you are > saying that there will be a single switch controlling everything. If > so, I believe this switch represents a single point of failure, which > is generally undesirable for flight critical electrical items - at > least when it comes to switches... If the switch falls apart, the > engine could stop running(?). > > Matt[/quote] > ________________________________ Message 11 ____________________________________ Time: 10:41:10 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Re: Bridge Diodes use Eric M. Jones wrote: > The Vf of a diode is a strongly influenced by current. A diode can be 0.7 Vf at zero Amps, and 1.0 Vf at 10A and 1.2 Vf at 12.5. For this you have to read the data sheet. What?! Radio Shack doesn't supply one?! Then just guess and hope you're right. Double up on the life insurance, too. > > Wow! Hyperbole and fearmongering. All in the same post. Are you sure you don't work for those 'news" organizations that tell us how we're killing all our children with minute traces of pesticides in our apples? You could have a career there, you know. You're trying to sell a product with minor improvements in areas that don't matter. Your diode uses half the power. We get it. The only time that would possibly mean anything is in a power out situation. In that situation, it will be removed from the circuit with a switch. The rest of the time, the RadioShack solution is wasting 12W of heat. That is 0.016 horsepower [international], which will mean the difference between hitting the trees versus warbird type climb out (NOT!). If a system is so loaded that 12W makes a difference during normal operations the plane won't be flying much anyway. The alternator/generator will be constantly burning up. You state your solution doesn't weigh as much. OK. Some guys obsess over every ounce. More power to them. If I needed 100 of these, it might make a difference. The call out is for exactly one in most cases. The draft in the closed hangar when I weigh my plane will have more effect on the finish weight. The Radio Shack rectifier has been recommended, and presumably used by builders, for years. It has proven adequate to the tasks asked of it. It was chosen for its price, availability, and ease of construction. If it there had been any instance of them causing harm, financial or physical, someone somewhere would have said something about it. Enough with the smoke, mirrors and demagogy. You stated the benefits of your solution. Some see validity to your claims and buy your products, just like some people swear by mystery chemical fuel additives. Most took a look and responded with a big "Ho-hum". To suggest at this point that a Radio Shack rectifier would require someone to need more life insurance in an attempt to sell more product is at best ridiculous, and at worst downright scandalous. ________________________________ Message 12 ____________________________________ Time: 11:06:15 AM PST US Subject: Re: AeroElectric-List: Re: Bridge Diodes use From: "Matt Prather" > > snip > 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....) > Glad I can bust your chops a bit.. :) Stay cool... > -------- > Eric M. Jones > www.PerihelionDesign.com > 113 Brentwood Drive > Southbridge, MA 01550 > (508) 764-2072 > emjones@charter.net > Regards, Matt- ________________________________ Message 13 ____________________________________ Time: 11:29:36 AM PST US From: "Dave VanLanen" Subject: AeroElectric-List: Creation Of Wiring Diagram For builders that are creating a wiring diagram, what are you using to create it? Are you creating with pencil and paper, or have you found any way to computerize it? Is a tool such as TurboCAD capable of creating a large full-aircraft drawing that can then be printed out? Dave ________________________________ Message 14 ____________________________________ Time: 11:42:03 AM PST US From: "Ron Shannon" Subject: Re: AeroElectric-List: Drilling Switch holes in aluminum? On Wed, Jun 11, 2008 at 10:00 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 vendor's recommendation and not mount them even more loosely. So to respond to your query, no, I don't think 1/2" holes are a good idea for these switches. Ron ________________________________ Message 15 ____________________________________ Time: 11:42:03 AM PST US From: "Roger & Jean" Subject: AeroElectric-List: "Dead horse" Lets not beat the bridge diodes any more!! ________________________________ Message 16 ____________________________________ Time: 11:57:32 AM PST US From: Ernest Christley Subject: Re: AeroElectric-List: Creation Of Wiring Diagram Dave VanLanen wrote: > For builders that are creating a wiring diagram, what are you using to > create it? Are you creating with pencil and paper, or have you found any > way to computerize it? Is a tool such as TurboCAD capable of creating a > large full-aircraft drawing that can then be printed out? > > Dave > > I'm using Dia, an open-source diagramming tool. ________________________________ Message 17 ____________________________________ Time: 12:27:44 PM PST US From: LarryMcFarland Subject: Re: AeroElectric-List: Creation Of Wiring Diagram Hi Dave, I've found TurboCAD very nice for doing electrical plans and 3D drawings as well. It's a full featured program that's reasonable to buy. After a life with AutoCAD and ProE, it's a better personal solution for the individual designer. These drawings were done in version 10, but they've been maintained thru version 15. http://www.macsmachine.com/images/electrical/full/primary-wiring.gif http://www.macsmachine.com/images/largeassembly2/full/eltdwg.gif Awesome program easy to learn............ Larry McFarland at www.macsmachine.com Dave VanLanen wrote: > > For builders that are creating a wiring diagram, what are you using to > create it? Are you creating with pencil and paper, or have you found > any way to computerize it? Is a tool such as TurboCAD capable of > creating a large full-aircraft drawing that can then be printed out? > > Dave > > * > * ________________________________ Message 18 ____________________________________ Time: 12:39:33 PM PST US From: "Vernon Little" Subject: RE: AeroElectric-List: Creation Of Wiring Diagram Here's a link to a great schematic tool (free) and my RV-9A wiring diagram. I prefer to use electrical CAD toos for schematics, rather than the mechanical CAD packages. Click to www.vx-aviation.com (link at top or scroll to bottom of page. I have some other builders who've promised to provide me their schematics as well-- I'll post them as I get them. Thanks Vern Little -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ernest Christley Sent: June 11, 2008 11:54 AM Subject: Re: AeroElectric-List: Creation Of Wiring Diagram --> Dave VanLanen wrote: > For builders that are creating a wiring diagram, what are you using to > create it? Are you creating with pencil and paper, or have you found > any way to computerize it? Is a tool such as TurboCAD capable of > creating a large full-aircraft drawing that can then be printed out? > > Dave > > I'm using Dia, an open-source diagramming tool. ________________________________ Message 19 ____________________________________ Time: 12:58:41 PM PST US From: ptrotter@optonline.net Subject: Re: AeroElectric-List: Re: Bridge Diodes use All this banter has been very interesting, but I think some people are missing part of the point here. The power dissipation is only one issue in diodes and the lessor important issue in my opinion. It is easy to deal with heat dissipation with the proper heat sink. What concerns me is the voltage drop across a normal diode. I don't to want to lose 1.2 volts if the alternative is to lose less by using a Schotky diode that costs only pennies more. This is especially critical if your alternator fails and you are on battery alone. This voltage drop could be the difference between keeping things running properly and not. 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. 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. Paul Trotter RV-8 Finishing the Wiring ----- Original Message ----- From: Ernest Christley Subject: Re: AeroElectric-List: Re: Bridge Diodes use > > Eric M. Jones wrote: > > The Vf of a diode is a strongly influenced by current. A diode > can be 0.7 Vf at zero Amps, and 1.0 Vf at 10A and 1.2 Vf at > 12.5. For this you have to read the data sheet. What?! Radio > Shack doesn't supply one?! Then just guess and hope you're > right. Double up on the life insurance, too. > > > > > > Wow! Hyperbole and fearmongering. All in the same post. > > Are you sure you don't work for those 'news" organizations that > tell us > how we're killing all our children with minute traces of > pesticides in > our apples? You could have a career there, you know. > > You're trying to sell a product with minor improvements in areas > that > don't matter. Your diode uses half the power. We get it. The > only > time that would possibly mean anything is in a power out > situation. In > that situation, it will be removed from the circuit with a > switch. The > rest of the time, the RadioShack solution is wasting 12W of > heat. That > is 0.016 horsepower [international], which will mean the > difference > between hitting the trees versus warbird type climb out (NOT!). > If a > system is so loaded that 12W makes a difference during normal > operations > the plane won't be flying much anyway. The alternator/generator > will be > constantly burning up. You state your solution doesn't weigh > as much. > OK. Some guys obsess over every ounce. More power to them. > If I > needed 100 of these, it might make a difference. The call out > is for > exactly one in most cases. The draft in the closed hangar when > I weigh > my plane will have more effect on the finish weight. > > The Radio Shack rectifier has been recommended, and presumably > used by > builders, for years. It has proven adequate to the tasks asked > of it. > It was chosen for its price, availability, and ease of > construction. If > it there had been any instance of them causing harm, financial > or > physical, someone somewhere would have said something about it. > Enough > with the smoke, mirrors and demagogy. You stated the benefits > of your > solution. Some see validity to your claims and buy your > products, just > like some people swear by mystery chemical fuel additives. Most > took a > look and responded with a big "Ho-hum". To suggest at this > point that a > Radio Shack rectifier would require someone to need more life > insurance > in an attempt to sell more product is at best ridiculous, and at > worst > downright scandalous. > > > > > > > > ________________________________ Message 20 ____________________________________ Time: 01:00:22 PM PST US From: "Hinde, Frank George (Corvallis)" Subject: RE: AeroElectric-List: Creation Of Wiring Diagram When I built the RV I hand drew each of the circuits on the back of a white door in the shop with a Sharpie pen...Easy to correct and modifiy with a solvent rag as you go along..Its still there today and one day I may transfer it to a more "Portable" format..One day..:) -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ernest Christley Sent: Wednesday, June 11, 2008 11:54 AM Subject: Re: AeroElectric-List: Creation Of Wiring Diagram --> Dave VanLanen wrote: > For builders that are creating a wiring diagram, what are you using to > create it? Are you creating with pencil and paper, or have you found > any way to computerize it? Is a tool such as TurboCAD capable of > creating a large full-aircraft drawing that can then be printed out? > > Dave > > I'm using Dia, an open-source diagramming tool. ________________________________ Message 21 ____________________________________ Time: 02:34:31 PM PST US From: Richard Tasker Subject: Re: AeroElectric-List: Re: Bridge Diodes use I suspect that it wasn't that at all. I suspect it was just someone writing the installation document that "understood" that diodes have about 0.6V drop. It is quite obvious that whomever wrote this didn't know a whole lot about ratings and power dissipation. They didn't know that there is no such thing as a "12W" heatsink without knowing a few more parameters. On the other hand, kudos for trying to educate users! Dick Tasker Eric M. Jones wrote: > 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 22 ____________________________________ Time: 05:40:08 PM PST US From: Kevin Horton Subject: Re: AeroElectric-List: Drilling Switch holes in aluminum? On 11 Jun 2008, at 14:38, Ron Shannon wrote: > On Wed, Jun 11, 2008 at 10:00 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 vendor'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 job - the switches fit very well. -- Kevin Horton RV-8 (FInal Assembly) Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 23 ____________________________________ Time: 09:06:09 PM PST US From: "Dennis Jones" Subject: AeroElectric-List: Boost pumps Bob In the information you sent on the smoke pump wiring, you showed the ground being switched and the positive going directly to the pump. Should the electric fuel be wired the same way? 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