---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 02/06/06: 12 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:12 PM - Re: 12 Volt DC Bench Power Supply (Bill Dube) 2. 03:12 PM - Re: Re: AeroElectric-List Digest: 29 Msgs - 02/04/06 (Bill Dube) 3. 03:19 PM - Re: 12 Volt DC Bench Power Supply (Bill Dube) 4. 06:46 PM - Flyable_Brassboards (Robert L. Nuckolls, III) 5. 07:19 PM - Alternator Stator Terminal (Roger & Alice Hoffman) 6. 07:19 PM - Alternator Stator Terminal (Roger & Alice Hoffman) 7. 08:24 PM - Bus Load Analysis (Jerry Grimmonpre) 8. 08:24 PM - Re: Alternator Stator Terminal (Robert L. Nuckolls, III) 9. 08:37 PM - Re: Flyable_Brassboards (Richard E. Tasker) 10. 10:06 PM - Re: Bus Load Analysis (Brian Lloyd) 11. 10:32 PM - Wire sizing. (DEAN PSIROPOULOS) 12. 11:15 PM - Re: 24v lamps in 14v system (Speedy11@aol.com) ________________________________ Message 1 _____________________________________ Time: 03:12:52 PM PST US From: Bill Dube Subject: Re: AeroElectric-List: 12 Volt DC Bench Power Supply --> AeroElectric-List message posted by: Bill Dube I use a Toshiba laptop power supply. I put clup leads on it. It delivers 15 volts @ 2 amps (good for charging batteries). I put a power doide in series with it to get 14.3 volts. (Just like the alternator with a full battery.) Brian Lloyd wrote: >--> AeroElectric-List message posted by: Brian Lloyd > > >Wngsfrmhvn@aol.com wrote: > > >>--> AeroElectric-List message posted by: Wngsfrmhvn@aol.com >> >>My first post to any list, so hope it works. >> >>I picked up a computer power supply a while back on a whim. 550 watt Antec, >>says it will deliver 24A at 12V, 40A at 5V, and 32A at 3.3V. Don't know if >>it goes to 13.8 or whether it's even suitable for benchtop use. It was $100 >>on eBay some time ago, prob not the best deal goin but... >> >> > >You can use computer supplies but many of them have minimum loads for >all three voltages for them to work properly. That means you have to >draw some current from the 5V and 3.3V outputs in order for the 12V >output to work properly. > >And, no, there usually isn't an adjustment that will let you crank up >the voltage to 13.8V. > >I have an old Astron 35A linear supply with variable voltage and current >limit. It works wonderfully for this kind of work. You set the current >limit just above what you expect to need and any accidental >short-circuit is protected by the supply's current limit. > > > ________________________________ Message 2 _____________________________________ Time: 03:12:52 PM PST US From: Bill Dube Subject: Re: AeroElectric-List: Re: AeroElectric-List Digest: 29 Msgs - 02/04/06 --> AeroElectric-List message posted by: Bill Dube The DC-DC converter will be pricey (and heavy.) Why not just run 12 volt position lights? If you have an experimental, may I suggest one of the LED position light kits I sell. Bill Dube' http://www.killacycle.com/Lights.htm speedy11@aol.com wrote: >--> AeroElectric-List message posted by: speedy11@aol.com > > Listers, >I have a question for you. >I have a 12V electrical system with two batteries and one alternator. I would like to power 24V position lights. What must I do to accomplish that? >Is there a 12V to 24V step up device that can be installed to power only those lights? I don't want to change the entire system to 24V. >Stan Sutterfield >www.rv-8a.net > > > > > > > > > ________________________________ Message 3 _____________________________________ Time: 03:19:35 PM PST US From: Bill Dube Subject: Re: AeroElectric-List: 12 Volt DC Bench Power Supply --> AeroElectric-List message posted by: Bill Dube Didn't realise you needed big amps. Iota is probably the most amps for the buck. You can switch it between 14.2 for charging and 13.8 for "float". Here is a listing: http://www.oksolar.com/battery_chargers/ Robert L. Nuckolls, III wrote: >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >At 09:50 PM 2/3/2006 -0500, you wrote: > > > >>--> AeroElectric-List message posted by: "J. Mcculley" >> >> >>Can someone recommend a source/model of bench power supply using 110V AC >>input with 12V DC output, capable of up to 15 amps DC? Thanks, >> >>Jim McCulley >> >> > > Do you really want 12v . . . or are you interested in > simulating an operating vehicle? 13.8v is a nominal bench > supply setting for emulating bus voltage. Here's a supply > I used to sell until they got so cheap that the margins > didn't fit my business model any more . . . > > > http://www.radiodan.com/misc/samlex1223.htm > > http://www.universal-radio.com/catalog/hamps/3747.html > > http://www.aaradio.com/cartfile/misc%20html/samlex.html > > > Bob . . . > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 06:46:53 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Flyable_Brassboards --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" Many times over the years, I've had to fabricate little circuits for some task wherein I needed the flexibility of a brass-board but with a reasonable degree of hardness suited for flight. I had occasion to dig out an old tool today for another task and thought I'd share it with the List. See: http://www.aeroelectric.com/Pictures/Tools/flyable_brassboard_1.jpg http://www.aeroelectric.com/Pictures/Tools/flyable_brassboard_2.jpg I cut down a strip of experimental brass-board stock and with a tad bit of sculpting on the belt sander, I was able to fit it to the inside of the lid on this die-cast box. Add a d-sub or other handy connector and you've got an enclosure with features that permit quick fabrication but with reasonable robustness for handling when closed up. If I expect unusual vibration, I'll use hot-glue to stick the components and wires down to the board. The hot glue doesn't run into the holes and strips off after the experiment is done. The circuit in the pictures is a gain of 100 amplifier I needed to amplify a strain gage signal up to the range of my poor-man's data acquisition system. The all-metal enclosure lends itself to the shielding of relatively sensitive circuits. I keep several such prepared boxes laying around and they've saved a lot of time when I needed to get something up and running . . . today. In this case, I'm setting up the data acquisition system to get some numbers on the performance of a Schumacher Wonder Charger . . . lots of push-buttons and indicators. Really cool battery charger. The goal is to deduce return on investment and real utility of this tool in the ownership and operation of and airplane (or any other vehicle fitted with a battery). I need a gain of 60 amplifier for the battery ammeter shunt. If any of you are inclined to craft specialty circuits that are best flight tested before committing to etched circuit board . . . or you just need a one-time circuit for a test, I can recommend the technique illustrated here. Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 5 _____________________________________ Time: 07:19:51 PM PST US From: "Roger & Alice Hoffman" Subject: AeroElectric-List: Alternator Stator Terminal --> AeroElectric-List message posted by: "Roger & Alice Hoffman" I'm wiring my experimental per Z-11. I have installed a Continental IO-240-B which came (new) with their (TCM) 60A Alternator installed. This alternator has a threaded terminal identified as 'Stator', as well as the terminals marked Battery, Field, and Ground. Can anyone tell me if this alternators 'stator' terminal needs a connection of some kind? Or leave it unconnected? A search of the archives revealed nothing to me, nor did the Continental Engine Operator's & Maintenance Manuals. Thanks in advance for any advice. R. Hoffman ________________________________ Message 6 _____________________________________ Time: 07:19:51 PM PST US From: "Roger & Alice Hoffman" Subject: AeroElectric-List: Alternator Stator Terminal --> AeroElectric-List message posted by: "Roger & Alice Hoffman" I'm wiring my experimental per Z-11. I have installed a Continental IO-240-B which came (new) with their (TCM) 60A Alternator installed. This alternator has a threaded terminal identified as 'Stator', as well as the terminals marked Battery, Field, and Ground. Can anyone tell me if this alternators 'stator' terminal needs a connection of some kind? Or leave it unconnected? A search of the archives revealed nothing to me, nor did the Continental Engine Operator's & Maintenance Manuals. Thanks in advance for any advice. R. Hoffman ________________________________ Message 7 _____________________________________ Time: 08:24:30 PM PST US From: "Jerry Grimmonpre" Subject: AeroElectric-List: Bus Load Analysis --> AeroElectric-List message posted by: "Jerry Grimmonpre" Hi all ... I humbly ask for input on the following and maybe create new thought ... Load analysis: Pitot heat load vs. load of AOA (angle of attack) Sport instrument. Rob are you here? When considering the imbalance of the load effects of these two items ... it seems we squander a lot of amps on pitot heat when the AOA could substitute while using about .4 amps and include audible warnings, as well, while landing at any weight. In my reading of the Lancair list, I've found there has been zero incidents of moisture problems in the AOA ports in the outer wing D sections. This included heavy rain with the airplane tied outside. If this port is not affected by moisture, it seems to follow that icing may be less of a problem with this delta P port. This applies to the AOA system called AOA Sport, where the pressure differential is measured at the outboard wing D section. When considering pitot heat, as a 7.5A continuous load, it would increase most Continuous Bus loads by near 30-40%. Powering-up an AOA system pales in comparison at only .4 amps. Those of you with the AOA Sport ... have you found any moisture or frozen ports? How many have found pitot heat cleared up their airspeed indications within moments of turning on the pitot heat? What I'm trying to get at here is: do you think pitot heat should be listed as continuous amps used, considering the availability of AOA and it's low demand on amps? Regards ... Jerry Grimmonpre' ________________________________ Message 8 _____________________________________ Time: 08:24:30 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Alternator Stator Terminal --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:18 PM 2/6/2006 -0800, you wrote: >--> AeroElectric-List message posted by: "Roger & Alice Hoffman" > > >I'm wiring my experimental per Z-11. I have installed a Continental >IO-240-B which came (new) with their (TCM) 60A Alternator installed. This >alternator has a threaded terminal identified as 'Stator', as well as the >terminals marked Battery, Field, and Ground. > >Can anyone tell me if this alternators 'stator' terminal needs a >connection of some kind? Or leave it unconnected? > >A search of the archives revealed nothing to me, nor did the Continental >Engine Operator's & Maintenance Manuals. > >Thanks in advance for any advice. > >R. Hoffman The "Stator" terminal is the center tap on a "Y" connected stator winding. This terminal has been used in a variety of ways to sense whether or not the engine was turning the alternator, as a signal to drive various alternator failure detectors, ect. I've not seen a useful application of this signal in years. It exists only on alternators with "Y" connected windings. In any case, you can ignore this terminal. Bob . . . < What is so wonderful about scientific truth...is that > < the authority which determines whether there can be > < debate or not does not reside in some fraternity of > < scientists; nor is it divine. The authority rests > < with experiment. > < --Lawrence M. Krauss > ________________________________ Message 9 _____________________________________ Time: 08:37:23 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Flyable_Brassboards --> AeroElectric-List message posted by: "Richard E. Tasker" I understand what you are doing and know that you understand the limitations of this type of breadboard and will not use it for long or in any flight critical application. However, I am not sure that everyone reading this list does. This type of breadboard is good for bench testing of relatively low frequency (<1MHz or so) circuits. It has a relatively large capacitance between pins/insertion points which limits the high frequency utility and can provide unwanted feedback in sensitive circuits. It is also not very secure unless it is new and from a good quality manufacturer. The insertion points tend to get loose with time, especially if one inserts a larger lead one time and a smaller lead the next. I would recommend that one use these boards as they were intended - try out the circuit on the bench in a nice benign environment. When you are satisfied that it will do what you want, then purchase one of the PCBs available that exactly mimic the insertion points and buses and solder your circuit on that (for instance, Radio Shack Catalog #: 276-170 - http://www.radioshack.com/search/index.jsp?kwCatId=&kw=breadboard - fifth one down on the page). They are also available from Digikey. This will give a circuit that is stable and robust and could be used as a permanent installation if so desired. The rest of your suggestion (using the aluminum box) is a great idea! Dick Tasker Robert L. Nuckolls, III wrote: >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >Many times over the years, I've had to fabricate little circuits >for some task wherein I needed the flexibility of a brass-board >but with a reasonable degree of hardness suited for flight. > >I had occasion to dig out an old tool today for another task >and thought I'd share it with the List. See: > >http://www.aeroelectric.com/Pictures/Tools/flyable_brassboard_1.jpg > >http://www.aeroelectric.com/Pictures/Tools/flyable_brassboard_2.jpg > >I cut down a strip of experimental brass-board stock and with >a tad bit of sculpting on the belt sander, I was able to fit it to >the inside of the lid on this die-cast box. Add a d-sub or other >handy connector and you've got an enclosure with features that >permit quick fabrication but with reasonable robustness for handling >when closed up. If I expect unusual vibration, I'll use hot-glue >to stick the components and wires down to the board. The hot glue >doesn't run into the holes and strips off after the experiment is >done. > >The circuit in the pictures is a gain of 100 amplifier I needed >to amplify a strain gage signal up to the range of my poor-man's >data acquisition system. The all-metal enclosure lends itself to >the shielding of relatively sensitive circuits. I keep several such >prepared boxes laying around and they've saved a lot of time when >I needed to get something up and running . . . today. > >In this case, I'm setting up the data acquisition system to get >some numbers on the performance of a Schumacher Wonder Charger . . . >lots of push-buttons and indicators. Really cool battery charger. >The goal is to deduce return on investment and real utility of >this tool in the ownership and operation of and airplane (or any >other vehicle fitted with a battery). I need a gain of 60 amplifier >for the battery ammeter shunt. > >If any of you are inclined to craft specialty circuits that >are best flight tested before committing to etched circuit >board . . . or you just need a one-time circuit for a test, >I can recommend the technique illustrated here. > > Bob . . . > -- Please Note: No trees were destroyed in the sending of this message. We do concede, however, that a significant number of electrons may have been temporarily inconvenienced. -- ________________________________ Message 10 ____________________________________ Time: 10:06:29 PM PST US From: Brian Lloyd Subject: Re: AeroElectric-List: Bus Load Analysis --> AeroElectric-List message posted by: Brian Lloyd Jerry Grimmonpre wrote: > I humbly ask for input on the following and maybe create new thought ... > Load analysis: Pitot heat load vs. load of AOA (angle of attack) Sport > instrument. > Rob are you here? I like AoA. It is one of the most useful instruments in an airplane. I also know that neither AoA nor ASI are going to be much use when the wing is iced up. Ice changes the airfoil shape and possibly the effective angle of incidence. The wing will stall at a different airspeed and probably a different angle of attack as separation of airflow is likely to occur sooner. So it doesn't much matter. Well, there is one thing: if your ASI is working and you experience stall buffet at some airspeed, at least the ASI will give you some idea when you are in the ballpark again. In that it might be of some use if the wing is iced up. And your AoA pressure ports will probably be covered with the ice anyway. But I still like that AoA instrument. I had one on my previous CJ6A and verified its calibration from 1/4G all the way up to 5Gs. It made flying acro a lot more comfortable because I could always just take the wing to zero alpha and wait until I had more airspeed to recover. I never had to deal with the airplane departing if I didn't want to. -- Brian Lloyd 361 Catterline Way brian-yak at lloyd dot com Folsom, CA 95630 +1.916.367.2131 (voice) +1.270.912.0788 (fax) I fly because it releases my mind from the tyranny of petty things . . . - Antoine de Saint-Exupery ________________________________ Message 11 ____________________________________ Time: 10:32:11 PM PST US From: "DEAN PSIROPOULOS" Subject: AeroElectric-List: Wire sizing. --> AeroElectric-List message posted by: "DEAN PSIROPOULOS" Lectric Bob: I've been doing the wiring diagrams for my all electric RV-6 and using some of your autocad stuff on the AEC CD as examples and starting points. Since I'm just hacking at Autocad these help get me going faster than if I had to start from scratch, thanks for sharing your hard work with us. Couple questions on wire sizing. I originally bought the Whelen strobe kit (A600) that has both the side and aft position lights with strobe in each wingtip mounted assembly (no tail position required). I later decided to buy the combination tail position light/strobe combo as an addition in order to help people see me better from the rear. I now have 5 position lights at 2.2 amps each for a total of 11 amps of load on the circuit. I would like to run them all from one switch and have ONE wire running from the switch down through the center console of the airplane through the spar to a distribution block under the floor. I've been scratching my head a little and reading and re-reading the section in your book about "Wire Selection and Installation". Using the chart for temp rise vs wire ga vs current capacity, it looks like a 16 GA wire would have appx a 30 deg C temp rise with 11 amps flowing through it. If I convert that to an appx Farenheit equivalent it becomes something like an 86 deg temp rise. If ambient is a Florida summer with the OAT at 90 deg (F) and I add these two temps together I get 176 degrees (F) temp in free air with 11 amps in the 16 GA wire, correct? Running this wire down through the tight confines of my center console means that it will be near several other wires and without lots of cooling air so I would assume that one would see the full 176 degrees around that wire in that confined space. This is not beyond the capabilities of the Tefzel wire I'm using but still very hot to the touch and warmer than I feel comfortable with. So if I drop down to a 14 GA wire it looks like the temp rise would be appx 13 deg C or 55 F which gives about a 145 deg wire temp in free air. The is still going to be pretty warm to the touch and I'm thinking maybe it should be derated a bit more but don't really want to run a 12 GA wire and am not 100% sure it's needed (although on a night flight that wire will see the full 11 amps for the entire period of time). Are my assumptions here correct and am I really going to experience 176 deg wire temp with 11 amps in a 16 GA wire on a 90 deg day? If so do you think dropping to 14 GA would be sufficient or should I make it larger? Since I don't really want to run a 12 GA wire through the tight space would two 16 or 14 GA wires work equally as well or would the current shared by each be unequal with the resultant heating of each wire also unequal (assuming they are tied together at both ends)? Is there a good "rule of thumb" for wire sizing with respect to temp rise (ie. Equipment that runs continuously should not have wire temps higher that would be uncomfortable to touch or some such thing). Since this wire is only about 6 feet long the voltage drop through it shouldn't be a significant factor that I see (4/1000 ohms per foot*6 feet*14 volts = .33 volts) so that leaves temperature. Also, I see on your diagrams for landing and recognition lights you show a resistor of unknown value between the ground connection and the light. I assume this is simply there to remind us that there is some loss in lines that long and also some loss in the return line (aircraft structure). Is this assumption correct or is there a reason for the resistors there? Any other word of wisdom would be most welcome. Thanks. Dean Psiropoulos RV-6A N197DM Knee deep in Autocad and wire ________________________________ Message 12 ____________________________________ Time: 11:15:10 PM PST US From: Speedy11@aol.com Subject: AeroElectric-List: Re: 24v lamps in 14v system --> AeroElectric-List message posted by: Speedy11@aol.com In a message dated 02/06/06 3:08:26 AM Eastern Standard Time, aeroelectric-list-digest@matronics.com writes: > Listers, >I have a question for you. >I have a 12V electrical system with two batteries and one alternator. I >would like to power 24V position lights. What must I do to accomplish that? >Is there a 12V to 24V step up device that can be installed to power only >those lights? I don't want to change the entire system to 24V. >Stan Sutterfield Have you considered changing the light bulbs in the position light fixtures? They're generally available in both 12 and 24 volt versions. Bob . . . The LED position lights are not available in 12V - only 24V. Is there a way to convert 12V to 24V so as to power the lights? Stan Sutterfield