---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Fri 11/07/03: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:43 AM - Ipods at Altitude (Treff, Arthur) 2. 07:43 AM - MFJ-259B (Fergus Kyle) 3. 08:08 AM - Re: Ipods at Altitude (BobsV35B@aol.com) 4. 08:36 AM - Circuit breakers (Glen Matejcek) 5. 09:14 AM - circuit breakers (Glen Matejcek) 6. 10:03 AM - Re: circuit breakers (Matt Prather) 7. 11:14 AM - Re: Battery Chargers (MikeM) 8. 02:55 PM - Re: Circuit breakers (David Schaefer) 9. 04:18 PM - Re: Panel Input (royt.or@netzero.com) ________________________________ Message 1 _____________________________________ Time: 07:43:06 AM PST US Subject: AeroElectric-List: Ipods at Altitude From: "Treff, Arthur" --> AeroElectric-List message posted by: "Treff, Arthur" Old Bob, Thanks for the heads-up on the iPod, first I"ve heard of this problem. Any idea where your info came from about ipods not liking altitude and where I can get more on this? I know that the device is a hard disk, and as such it has heads that 'fly' over the disc surface at a dimension in the sub micro-inch region. I though that disks got into trouble above 25,000', but maybe not? Any help would be appreciated. Art ________________________________ Message 2 _____________________________________ Time: 07:43:06 AM PST US From: "Fergus Kyle" Subject: AeroElectric-List: MFJ-259B --> AeroElectric-List message posted by: "Fergus Kyle" Gabe, Excellent choice - bit pricey for one aircraft but super when shared. HOWEVER it is very delicate when it comes to power source. Dont fail to ensure that you provide the requisite voltage first, THEN turn it on - or the smoke retainer lets go and it takes the long road back to repair. You don't need to 'hook it up' physically as it does its job inductively and the manual should show this, otherwise give me a call privately and will advise. I belive the induction accessories are with the box. My experience, even with oldtimer hams, is never loan it out - as even the most careful tend to forget and putting a tenth of a watt thru will blow its brains out. Take it to them and perform the task yourself is the best policy. Nevertheless you will find the ideal components and settings to mate the antenna to the transmitter by means of the MFJ259B. Good hunting, Ferg VE3LVO Europa classic mono ________________________________ Message 3 _____________________________________ Time: 08:08:25 AM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: Ipods at Altitude --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 11/7/03 9:44:11 AM Central Standard Time, Arthur.Treff@Smartm.com writes: Thanks for the heads-up on the iPod, first I"ve heard of this problem. Any idea where your info came from about ipods not liking altitude and where I can get more on this? I know that the device is a hard disk, and as such it has heads that 'fly' over the disc surface at a dimension in the sub micro-inch region. I though that disks got into trouble above 25,000', but maybe not? Any help would be appreciated. Good Morning Art, It came up on The Beech-Owners list. I will see if I can locate the source, but I don't generally save much. Old Bob ________________________________ Message 4 _____________________________________ Time: 08:36:14 AM PST US From: "Glen Matejcek" Subject: AeroElectric-List: Circuit breakers MIME_BOUND_NEXTPART --> AeroElectric-List message posted by: "Glen Matejcek" Howdy- While comparison shopping on the web I discovered that one can get CB's that will work in ATC / automotive style fuse blocks. Does anyone have any insights as to the reliability / quality / applicability of these devices to our homebuilts? Glen Matejcek All-electric RV-8, pulling wires aerobubba@earthlink.net ________________________________ Message 5 _____________________________________ Time: 09:14:33 AM PST US From: "Glen Matejcek" Subject: AeroElectric-List: circuit breakers MIME_BOUND_NEXTPART --> AeroElectric-List message posted by: "Glen Matejcek" Howdy- While comparison shopping on the web I discovered that one can get CB's that will work in ATC / automotive style fuse blocks. Does anyone have any insights as to the reliability / quality / applicability of these devices to our homebuilts? Glen Matejcek All-electric RV-8, pulling wires aerobubba@earthlink.net ________________________________ Message 6 _____________________________________ Time: 10:03:48 AM PST US Subject: Re: AeroElectric-List: circuit breakers From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Hi Glen, I don't think I would use the breakers you are describing. The ones I have seen have moving parts (lowering reliability), and are more expensive than fuses. I especially wouldn't use any that automatically reset. That's just asking to periodically get smoke in the cockpit, should something in the system fail while in flight. The only advantage I can think of is that if you use the manually resettable style, you save the replacement cost of the fuse. But at less $.30 each for ATC fuses, I can't see that replacement costs are a real issue. If you design the system properly, you might only have to put fuses in the system once in its lifetime. Regards, Matt- N34RD > --> AeroElectric-List message posted by: "Glen Matejcek" > > > Howdy- > > While comparison shopping on the web I discovered that one can get CB's > that will work in ATC / automotive style fuse blocks. Does anyone have > any insights as to the reliability / quality / applicability of these > devices to our homebuilts? > > > Glen Matejcek > All-electric RV-8, pulling wires > aerobubba@earthlink.net > > ________________________________ Message 7 _____________________________________ Time: 11:14:40 AM PST US From: MikeM Subject: AeroElectric-List: Re: Battery Chargers --> AeroElectric-List message posted by: MikeM On Thu, 6 Nov 2003 Pacer15P@aol.com wrote: > Mike, > > Read your response about chargers and snake oil and agree with your comments. > I would appreciate your help with my questions. Hi Dick, hope you dont mind if I also forward my reply back to the list. > What charger, amp size, etc., would you recommend to slightly > charge or maintain a std lead acid 35 series aircraft battery? By "maintain", I assume you are concerned about what happens to the typical G35 aircraft battery during times when the aircraft is not flown regularly (say bi-weekly). The answer is complicated. As long as the aircraft is flown once every couple of weeks, assuming that the generating capacity in the aircraft exceeds the current being drawn by the instruments, avionics and lights, (so that the reserve capacity is available for charging the battery), and that the voltage regulator gets the battery voltage up to 14.2+ Volts for the duration of a flight, then you dont need to do anything involving external chargers. If the aircraft generation capacity or regulation is suspect, then instead of tinkering with chargers, you really should fix the root cause (which is install enough generating capacity, adjust the voltage regulator to produce said 14.2+ V, fly the airplane an hour or two every two weeks, etc.) The reason for the "every two weeks" statements above are based on the physics of flooded-cell batteries. There are two parts to prevent degradation of a battery which is sitting unused for periods of weeks to months. Lets call this "battery maintenance". Note that "maintenence" only needs to be done when the aircraft is not regularly flown, as in the winter months. First, you need to keep the battery from discharging itself even after disconnecting anything that draws current, which should be the case if you turn off your Master. Second, you need to periodically stir the acid in battery to prevent the acid from stratifying with the lowest specific gravity on top. All lead acid batteries loose charge just by sitting around. at 100 deg F, a G35 will loose 10%-20% of its capacity per month. In cold weather, the self discharge rate is much lower. So if you want to maintain a battery near full capacity, you have to replace the charge lost due to self discharge. It requires only ~ 0.25A to make up for the leakage. Preventing self discharge is usually accomplished by "floating" the battery using a voltage-limited charger, which puts out 13.5 +-0.1 V open-circuit. Most commercial automotive chargers such as you would get at Sears or Checker are not voltage limited accurately enough to leave them connected to a battery for more than 24 hours!!! They are suitable for recharging a run-down battery, but they must be manually disconnected after a few hours. The better models of the automotive chargers have a time clock shutoff which means you dont have to drive back to the airport to shut off the charger. If you have the disipline, you can "maintain" an unused battery through the winter months by giving it an 4-6 hour charge every 30 days or so, relying on the clock in the charger to shut it off, otherwise you have to drive back to airport to disconnect the charger. One of the primary causes of loss of capacity of batteries is sulfation of the lead plates; Sulfation happens when the battery is allowed to sit around in a partially or totally discharged state for long periods; sulfation is minimised by keeping the Specific Gravity of the acid high (fully charged) see: http://www.sierrasolar.com/design/b_leadbattery.htm The acid in a stationary battery (not being sloshed around in a car, boat, motorhome, airplane) will stratify, meaning that the Specific gravity at the top of the battery will be much less that at the bottom. Due to low SG at the top, the top parts of the plates will sulfate first, reducing the capacity and cold cranking amperage of the battery. The solution to stratification is to mechanically stir the acid, which happens normally if you take your battery for a ride in the car, or for a flight in the airplane. However, if the airplane/car is parked for six months, what then? A good substitute for mechanical agitation is to periodically (once every two weeks or so) connect the battery to a charger whose voltage is set to 14.4+ V for a few hours. In the industry this is sometimes called "equalization", but the primary benefit comes from charging the battery hard enough to evolve gas (hydrogen at one plate, oxygen at the other). The bubbles rise through the acid, stirring it as they go, mixing the weaker acid with the stronger. So, for total automatic unattended maintenance of batteries, the charger has to float at 13.5V continuously, and every two weeks or so, it needs to bump up the voltage to about 14.4V while delivering a few amps for a few hours, and then revert back to the float mode. If the aircraft is flown regularly, then you dont have to bother with equalization. > Is it feasible to leave the master switch "on" to activate the > solenoid and charge/maintain the battery thru the cigar > lighter circuit? > Do you think this might create any unforeseen > problems such as overheating the solenoid if left unattended > for several days at a time etc. Or is this just a plain bad > idea? Its just a bad idea. Overheating of the solenoid shouldn't be a problem, because the solenoid is rated for it. However, your charger has to deliver approximately 1.5A to the coil in the solenoid, plus whatever unswitched loads there are in the aircraft (like the fuel gauges) Suppose someone unplugs your charger? Now the solenoid/gauges will kill your battery. Its not hard to wire in a fused connector which will allow direct access to the battery with the master off. >Is it possible to overcharge a battery with today's low > amp chargers? Yes. You have to buy a charger specifically made for "float charging", like the BatteryTender http://www.batterytender.com/ If in doubt, connect your charger to a battery for 6 to 12 hours. Use an accurate digital voltmeter to measure the voltage between the battery terminals with the charger still charging. If the measured battery voltage after a few hours exceeds 13.6V, the charger is not suitable for long term float charging. In summary, if all you own is the typical Sears 10A charger with the time clock, then while the aircraft/motor home/boat is not being used, hook the charger to the battery with the time clock set to 6 hours. Go back and do it each month. That is the best you can do to prevent the battery from loosing capacity while inactive. During the six hours, the charger will put back the self discharge, and then it will bubble the battery just enough to stir the acid. This regemin is way better than just letting the battery sit idle for six months. MikeM (Batteries r us) Pacer '00Z Skylane '1MM ________________________________ Message 8 _____________________________________ Time: 02:55:47 PM PST US From: "David Schaefer" Subject: RE: AeroElectric-List: Circuit breakers --> AeroElectric-List message posted by: "David Schaefer" The only problem I found was that they are only available in 10,20,30 and 40 amp from BUSSMAN. Not the 1.5, 2, 5, 7 I needed for the panel etc. Regards, David -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Glen Matejcek Subject: AeroElectric-List: Circuit breakers --> AeroElectric-List message posted by: "Glen Matejcek" Howdy- While comparison shopping on the web I discovered that one can get CB's that will work in ATC / automotive style fuse blocks. Does anyone have any insights as to the reliability / quality / applicability of these devices to our homebuilts? Glen Matejcek All-electric RV-8, pulling wires aerobubba@earthlink.net = == == == == ________________________________ Message 9 _____________________________________ Time: 04:18:13 PM PST US Subject: AeroElectric-List: Re: Panel Input From: royt.or@netzero.com --> AeroElectric-List message posted by: royt.or@netzero.com Darwin, The panel in my simple Zenair Zodiac, N601RT, is similar to what you have planned. I have included my equipment differences between your plan and my actual panel in parenthesis Equipment list as follows (N601RT differences): Garmin 340 audio panel Garmin 430 GPS/Comm Garmin 106A CDI Garmin 330S transponder (N601RT Garmin 327) UPS SL 40 Comm (N601RT - Icom A23, not panel mounted wired to comm2) Trutrak 2 axis AP (N601RT - Digitrak) Dynon EFIS (N601RT uEncoder, Electric DG, AH, TC, 3 1/2 Airspeed) ACS2002 engine monitor (N601RT Grand Rapids EIS with fuel flow & Volt/Load meter from Lectric Bob) Approach systems wiring hub (N601RT panel built by Pacific Coast Avionics) EXP buss switch panel. (Acres of breakers, and switch breakers) Some sort of CD player (Portable CD/MP3 player, less than $50) Back up stuff will be 2.25" airspeed, altimeter, and T&B. (N601RT 2.25 altimeter) Ive added a 1 diameter clock from riderwearhouse (motorcycle goodies supplier). You could argue that the GPS has clock with seconds, but I prefer to have the analog display. See http://www.aerostich.com/riderwearhouse.store/3f94660209afda40271dd1f0ec070680/Offer/AddProduct/9027 I have independently powered backup GPS and comm provided with a GPS295 and Icom A23. Both of these have their own internal batteries and are powered from the plane under normal operation. The Garmin GPS295 is mounted on top of the glare shield, with a permanently mounted antenna AND wired to the Garmin 430. When I enter a flight plan in the 430, the flight plan is automatically loaded into the GPS295. Changes Id make plan to make are adding a dedicated antenna for the Icom A23 and making the A23 comm1 in the audio panel. Comm1 in the audio panel is significant because in the event of loss of power to the audio panel, comm1 is automatically connected to the headset. The uEncoder includes the compass module option and automatically provides air data information, including magnetic heading to the Garmin 430. The Rotax 912ULS in my plane has the standard 18A alternator and an optional 40A ND alternator driven by belt from the front of the engine. Each alternator has Bobs OV protections. Im using a single 18AH RG battery. Regards, Roy