can anyonwe tell me how to find the totl australian glider register? ron On 27 February 2013 20:55, tom claffey <[email protected]> wrote:
> Aircon? - I want one! :) > > ------------------------------ > * From: * Mike Borgelt <[email protected]>; > * To: * Discussion of issues relating to Soaring in Australia. < > [email protected]>; > * Subject: * Re: [Aus-soaring] LiFePo4 ~ Why not move to 24 volt systems? > * Sent: * Thu, Feb 28, 2013 12:44:04 AM > > You usually move to higher voltage to transmit greater power at the > same or lower current which reduces wiring weight. I suspect in light > aircraft the power requirement for the electrics is driven by systems other > than the avionics i.e electrically driven hydraulic pumps or simply > electrically driven flaps, landing gear retract etc. > There is consideration of going to 42 volts for cars for this reason. > > B50s work down to 10 volts, B300/B500/600/800 a little less. B400 and B700 > down to 4 volts.(internal boost regulator cuts in). A 12 v nominal SLA > battery is about to die at 11V terminal voltage when discharged at typical > glider rates. If you are losing more than 0.2 volts or so between the > battery and the instrument you need to fix the wiring, fuses switches etc. > > There doesn't seem to be any overwhelming reason to go to 24 volts in > gliders. I'll bet most "24 or 28 volt" avionics has a switch mode regulator > to get 14 volts before going to the rest of the gadget or simply to the 5 > volts or so required by the logic circuits. > > If we go to electric flaps and aircon like the Duckhawk this may change. I > think it has something like a 54 A-H battery. > > Mike > > > At 08:13 AM 28/02/2013, you wrote: > > Content-Type: multipart/alternative; > boundary="----=_NextPart_000_0056_01CE1593.E2557430" > Content-Language: en-us > > My contribution to the battery aspect of this thread is to question why we > are so infatuated by 12 volts? [I once wrote Standards, and Standards often > impede innovation] > > I also agree that the electrical systems must be designed and implemented > taking into consideration volts, amps, temperature high and low, wiring, > insulation, noxious gases, fusing, short circuit and thermal runaway, G > load, weight and many other factors > > At Oshkosh 2006 the Blue Mountains Avionics presentation said for light > aircraft the move to 24 volt systems was a no brainer, just so logical. > Most instrumentation and radio’s require 10 volts and a 12 volt system > decays to 10 volt reasonably fast. Microair’s need probably 10.5 before the > transmitter goes garbled, Cambridge falls over at about 8 volts. Mike > could perhaps comment on the minimums for Borgelt instruments. PDA’s and > XCSoar have a USB 5 volt input so may work longer on a 12 volt system? > Some avionics are designed for 35 volt DC maximum input [but XCOM and > Microair apparently have 16 ~ 17 volt maximum input specification] > > But starting with 24 volts gets much more out of the battery before > avionics fail. Even moving to say 16 volt to keep within radio > specification could lead to increased useful battery life. > > Cranking amps for starter motors is at the high drain end of the drain > spectrum but arguably is early in a batteries discharge cycle in the glider > application. > > So why not have 16 ~ 24 volt systems in gliders? > > Alan Wilson > [ARMIT Comm Eng] > Canberra > > *From:* [email protected] > [mailto:[email protected]] > *On Behalf Of *[email protected] > *Sent:* Wednesday, 27 February, 2013 8:58 PM > *To:* Discussion of issues relating to Soaring in Australia. > *Subject:* Re: [Aus-soaring] LiFePo4 > > Nice one Arie. > You do bring a bit of costing perspective into the argument here. > > The YouTube footage is interesting (horrific?), but I suspect basically > irrelevant. > > I think that any glider pilot who knows anything about the problem, does > not want to experience an inflight cockpit fire UNDER ANY CIRCUMSTANCES. I > know of one example, where the pilot was VERY happy to have survived the > experience - without having to bail out. He reported that fire - as in > burning - was NOT the problem. He reported that the amount of fumes and > smoke generated in an incredibly short time from the ignition of the > plastic wire covering due to shorting of the electrical system was in fact > the primary problem. For this unfortunate pilot, there were really two > problems: first he had to be able to breathe, and secondly he had to be > able to see what you are doing - basically impossible in a cockpit filled > with smoke! > > Re your statement "willing to replace a couple of batteries each year > ...." Probably a slip of the pen: As Bernard has pointed out a *high*quality > SLA gel cell type battery MAY last up to 9 or 10 years, but this is > hardly likely to be the norm. Five - seven years seems to be much more > realistic estimate. As far as I can tell, the life of the LiFePo4 batteries > is not claimed to be any better than this latter figure. > > At this point in time, LiFePo4 batteries are MUCH more expensive. However > I expect that in a few years time the price will have fallen, and many > glider pilots will be using these "new fangled" devices,. > > I suspect that I will need to replace my current glider batteries in the > near future. I do not have a max AUW of the non-loading bearing parts > problem - one valid argument for lighter batteries - and my power > consumption figures - high power consumption requirements are another valid > argument for using LoFePo4 - are relatively modest, so I have no intention > of using LifePo4 batteries for the replacement. > > What this whole discussion has crystallised for me is the requirement, > regardless of the type of battery selected, is to always use a high quality > battery manufactured by a reputable factory who stands behind their > product. [I have in the past tried "cheap" batteries, and regretted it.] > > Regards, > Gary > ----- Original Message ----- > From: Arie van Spronssen > To: Discussion of issues relating to Soaring in Australia. > Sent: Wednesday, February 27, 2013 6:56 PM > Subject: Re: [Aus-soaring] LiFePo4 > > Hi, > > When people start talking of glider batteries I laugh at their logic. We > have a toy that cost anywhere between 2 - 10k and upwards to keep in the > air each year (not including getting to and from the airfield and actually > getting it in the air) and they are not willing to replace a couple of > batteries each year for well under a $100. > > These fancy batteries may be ok but in the vast majority of gliders the > simple still works best and is cheap and safe. > > Yes I do play with these fancy batteries in my radio control toys but with > great care and they are always stored in a lipo safe bag. You only have to > watch this video to agree http://www.youtube.com/watch?v=mw8jb1KmAG8 yes > I know the newer ones are better but these are only small and look at how > they go up and even the newer ones can still have problems. > > regards, > Arie > > On 27/02/2013 12:52 PM, Future Aviation wrote: > > Hello all > > > > > > It just occurred to me that I have omitted to thank John > Parncutt > > > for his research and his willingness to share the findings with > us. > > > > > > Of course, in this context Mike Borgelt's professional advice > must > > > also be mentioned. Both contributions are extremely useful to > many > > > of my gliding friends including myself. Many thanks to both of > you! > > > > > > Believe it or not, the last set of SLA batteries powering the > engine > > > circuit in my ASH 25 lasted for 10 years. At the time I opted > for the > > > most expensive SLA batteries I could get my hands on and now it > appears > > > that the old saying holds indeed true. You only get what you > ........ > > > > > > Kind regards to > all. > > > > > > Bernard Eckey > > > > > > -----Original > Message----- > > > From: > [email protected] > > > [ > mailto:[email protected]] On Behalf Of > Mike > > > Borgelt > > > Sent: Wednesday, 27 February 2013 11:22 > AM > > > To: Discussion of issues relating to Soaring in > Australia. > > > Subject: Re: [Aus-soaring] > LiFePo4 > > > > > > As I said yesterday, do proper engineering on your battery > installation. > > > If you don't have real numbers for temperature limits, discharge > curves at > > > various rates, charging characteristics etc etc you aren't > doing > > > engineering, you're just > guessing. > > > A battery designed to start a racing motorbike and then be > recharged by the > > > alternator and floated at that voltage likely has quite > different > > > characteristics, design and longevity from one designed for > charging and > > > deep discharging over several hours then recharging. You can > also just stop > > > and get off the bike when the battery catches > fire. > > > Li batteries all need individual cell monitoring during charge > and use or at > > > least when charging after mostly > charged. > > > The problem with Ni MH batteries is the number of cells (10 for > a nominal 12 > > > V system). You will have at least one weaker cell which will > deep discharge > > > more than the others and will be undercharged or more likely the > other cells > > > will overcharge resulting in reduced battery life. Individual > cell > > > monitoring would help but with 10 cells vs 4 for Li it is a > pain. > > > 3 years isn't bad for a NiMH battery > pack. > > > Some people have a problem with max weight of non lifting parts > and a few > > > kilos saved may make the difference between flying in or > outside the > weight > > > and balance envelope. For these LiFEPO4 may be worthwhile but > use the > > > correct > cells. > > > The cylindrical Tenergy cells sold by these people have > engineering data and > > > are Underwriter Labs tested. The tests are published there too. > Start > > > here: > http://www.all-battery.com/lifepo4battery.aspx > > > I've dealt with them and they did what they said they > would. > > > Also these people may be of interest: The batteries seem to be > the same as > > > the Tenergy cells but with a different colour outer sleeve. > > > They have battery monitoring/cutoff circuitry available also. > You must use a > > > low voltage cutoff at > least. > > > http://lithbattoz.com.au > > > The old sealed lead acid batteries are OK. They are heavier > although in many > > > installations that may not matter. The capacity is usually > quoted at the 20 > > > hour rate. In modern gliders 1 amp continuous is not an unusual > load so > > > that's the 7 hour rate. Likely it is a 5 A-H battery at this > rate. Give it a > > > couple of dozen charge cycles and it is a 3 or 4 A-H battery and > you begin > > > to have problems. Note also the number of cycles you get is non > linear with > > > depth of discharge. Small % discharge you'll get lots of cycles. > Large % > > > discharge many, many fewer > cycles. > > > Size the battery to handle the longest flights and then use two > batteries. > > > Use one routinely, keep the other charged then when the first > battery dies > > > due to low capacity you have a known good battery. > > > Put that one in the first position then put a new one in > the standby > > > position. You should always have a good battery available > then. > > > If using some new type either learn enough to do an engineering > analysis or > > > find someone willing to do one for you. Otherwise these things > may get > > > needlessly banned or we have fires in gliders. It would be > embarrassing to > > > explain to your insurance compny why you had to bail out of your > burning > > > glider. > > > > > > Mike > > > > > > > > > _______________________________________________ > > > Aus-soaring mailing > list > > > > [email protected] > > > To check or change subscription details, > visit: > > > > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > > > > _______________________________________________ > > > Aus-soaring mailing > list > > > > [email protected] > > > To check or change subscription details, > visit: > > > > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > > > > > ------------------------------ > _______________________________________________ > Aus-soaring mailing list > [email protected] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring > ------------------------------ > No virus found in this message. > Checked by AVG - www.avg.com > Version: 2012.0.2238 / Virus Database: 2641/5635 - Release Date: 02/26/13 > > _______________________________________________ > Aus-soaring mailing list > [email protected] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring > > > _______________________________________________ > Aus-soaring mailing list > [email protected] > To check or change subscription details, visit: > http://lists.internode.on.net/mailman/listinfo/aus-soaring >
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