AeroElectric-List Digest Archive

Mon 01/03/11


Total Messages Posted: 15



Today's Message Index:
----------------------
 
     1. 04:34 AM - Re: is battery filter or dead weight? (Robert L. Nuckolls, III)
     2. 04:45 AM - Re: is battery filter or dead weight? (Jan de Jong)
     3. 06:36 AM - Re: Questions about the 9005 Low Voltage Module (Robert L. Nuckolls, III)
     4. 06:38 AM - Re: is battery filter or dead weight? (Robert L. Nuckolls, III)
     5. 06:45 AM - Re: is battery filter or dead weight? (Eric M. Jones)
     6. 02:13 PM - Re: Re: is battery filter or dead weight? (Robert L. Nuckolls, III)
     7. 02:19 PM - Regulator How Hot (rvg8tor)
     8. 04:36 PM - Re: is battery filter or dead weight? (Eric M. Jones)
     9. 05:33 PM - Re: Questions about the 9005 Low Voltage Module (Jared Yates)
    10. 07:09 PM - Re: Questions about the 9005 Low Voltage Module (Richard E. Tasker)
    11. 07:27 PM - Re: Re: is battery filter or dead weight? (Robert L. Nuckolls, III)
    12. 10:23 PM - CPC's (Tim Andres)
    13. 11:09 PM - Re: CPC's (Don)
    14. 11:31 PM - Re: CPC's (Werner Schneider)
    15. 11:43 PM - Re: CPC's (Don)
 
 
 


Message 1


  • INDEX
  • Back to Main INDEX
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 04:34:32 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: is battery filter or dead weight?
    At 11:23 AM 1/2/2011, you wrote: > >A question. >Is a fully charged 12V lead-acid battery held at 14V a voltage stabiliser? >People seem to think so but I doubt it. >If you disconnect the battery while the alternator consistently puts >out over 13V will there be much difference in AC components on the bus? >Is there an AC on top of DC internal impedance measurement out there >somewhere that I can't find a reference to? >I hope somebody knows more. I think you've already identified the battery filter myth . . . a myth I once propagated. There was a sort of "giant capacitor" quality ascribed to batteries that kind of made sense. Batteries are indeed a huge energy source/sink for their size. If you study battery behavior you'll discover that they are very non-linear devices. The term "internal impedance" does not describe a simple resistive or reactive loss. While a battery is being heavily discharged (say 12.0v and below) it can be said to have a very low internal impedance on the order of tens of milliohms. But while being charged at 14.0 volts and above, that impedance value rises. Worse yet, when the battery is fully charged, it's internal impedance goes waaayyyy up. This is why Mil-Std-704 tells us to EXPECT bus voltage excursions of 3v pk-pk over the range of 1000 to 5000 Hz on a 28v system (1/2 that on a 14 volt system). The expected/permissible levels drop off on either side of that band: Emacs! Further, 704 is silent as to whether or not there is a battery present. And it makes sense. A fully charge battery floating on a normal bus is electrically 'transparent'. If you experience an alternator runaway, the battery will offer a significant mitigating load that joins with system loads to drive the alternator into a current limited mode. This is helpful in holding down bus voltage while the ov protection system takes a few tens of milliseconds to shut it down. Obviously, when the alternator fails, the battery can be expected to provide the alternate source of energy albeit at reduced voltage. But as a "filter" small transients that we call noise, the battery is of no practical value. Dead weight? Hope not. The thoughtfully maintained battery is the most reliable source of energy on the airplane. Bob . . .


    Message 2


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 04:45:07 AM PST US
    From: Jan de Jong <jan_de_jong@casema.nl>
    Subject: is battery filter or dead weight?
    Thanks. I realise that the battery will not allow excursion below 12.5V and will be an increasing load above 15.5V as long as it lives. I wonder about its filtering role around 14V when it's neither drawing or supplying current which is the standard situation. What might be an equivalent load of capacitor, resistor and inductor combination? Jan The question is not urgent > Time: 02:37:38 PM PST US > From: "Noel R.C. Loveys" <noelloveys@yahoo.ca> > Subject: RE: AeroElectric-List: is battery filter or dead weight? > > > The battery in the circuit will help dissipate voltage spikes. If your > generator goes into an overvoltage charge situation it won't take long to > boil the battery. Once that happens the buss will go overvoltage too, > > Noel > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jan de > Jong > Sent: January 2, 2011 1:53 PM > Subject: AeroElectric-List: is battery filter or dead weight? > > > A question. > Is a fully charged 12V lead-acid battery held at 14V a voltage stabiliser? > People seem to think so but I doubt it. > If you disconnect the battery while the alternator consistently puts out > over 13V will there be much difference in AC components on the bus? > Is there an AC on top of DC internal impedance measurement out there > somewhere that I can't find a reference to? > I hope somebody knows more. > Thank you. > Jan de Jong >


    Message 3


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 06:36:22 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Questions about the 9005 Low Voltage Module
    At 07:57 AM 1/2/2011, you wrote: >Thanks Bob! Here are the readings that I get. Battery Voltage this >morning is 12.3. > >U107 Pin 1: 0 >U107 Pin 2: 2.38 >U107 Pin 3: .68 >U107 Pin 4: 0 >U107 Pin 7: 11.24 >U107 Pin 8: 11.49 > >U110 Pin 1: 0 >U110 Pin 2: 10.77 >U110 Pin 3: 0 >U110 Pin 4: 11.49 >U110 Pin 5: 7.66 >U110 Pin 6: 10.78 >U110 Pin 8: 11.49 Okay, all of the voltages you've measured are expected values with one exception. Pin 3 of U107 voltage is established by the voltage reference Z103 and SHOULD be within 30 millivolts or so of 2.50 volts. http://www.national.com/ds/LM/LM185-2.5.pdf The fact that you're reading only .68 volts suggests that Z013 is installed wrong. See data sheet for pinout orientation . . . Emacs! Note that the image is a BOTTOM view of the device. The pictures for assembly of the 9005 show the flat side of the device pointed toward the power transistor location. If you determine that the device IS installed wrong you should consider the best way to replace it. If you have the tools and experience to removed parts from a plated thru hole board, you have a high probability of re-using the original part. I very seldom pull a part off a board with any notion of reusing it. The value of the part is usually pretty small compared to the value of the whole. I usually clip the leads on the part to be removed so that they can be taken out of the holes one at a time thus minimizing hazard to the board. Bob . . .


    Message 4


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 06:38:46 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: is battery filter or dead weight?
    At 06:42 AM 1/3/2011, you wrote: > >Thanks. >I realise that the battery will not allow excursion below 12.5V and >will be an increasing load above 15.5V as long as it lives. >I wonder about its filtering role around 14V when it's neither >drawing or supplying current which is the standard situation. >What might be an equivalent load of capacitor, resistor and inductor >combination? I've never considered researching an "equivalency" . . . It would depend heavily both on size of the battery and its physical condition. Given that noise values for battery-in versus battery-out are indistinguishable from each other says that noise mitigation benefits, if any, are insignificantly small. Bob . . .


    Message 5


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 06:45:03 AM PST US
    Subject: Re: is battery filter or dead weight?
    From: "Eric M. Jones" <emjones@charter.net>
    It is a little hard to discover if big commercial aircraft have batteries at all. My guess is that they have some efficient small battery to start the APU, and not much more. Can an airplane be built without a battery? Sure. There is a large Russian airplane that can be parked all Winter, then started with the compressed air stored from a previous flight. If it doesn't start, you have your prisoners hand-pump in more compressed air. So having a battery is convenient for starting the airplane, and seems to be a stabilizing load for the alternator. If the battery is disconnected, plan on some other stabilization for the alternator, because what comes out of the alternator is a bumpy DC whose bumps are proportional the the alternator RPM. Modern electronics are perfectly capable of doing this as well as a big battery, but modern electronics are going to POL (Point-of-Load), where the "main" power supply is no longer forced to provide various voltages at various currents and various stabilities. Instead a single (and perhaps higher voltage) power line runs around the aircraft, and is then changed at the load to whatever the load needs by tiny little ICs. This has advantages from several angles, perhaps the main one being that the system supply and buses don't easily become obsolete. In my little airplane a-building, I plan an internally-regulated ND alternator and a power filter using a capacitor, and inductor, Zener and just a few other parts to give far better filtering than standard Cessnas. Why this is not routine practice mystifies me. I might also find a reason to put in a 1.0 F supercapacitor sitting on my shelf. Such a reason might be that it would reduce the wire size between my battery and the starter, while (it has been shown) cause the battery life to soar. -------- 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=325420#325420


    Message 6


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 02:13:30 PM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: is battery filter or dead weight?
    At 08:41 AM 1/3/2011, you wrote: > >It is a little hard to discover if big commercial aircraft have >batteries at all. My guess is that they have some efficient small >battery to start the APU, and not much more. Can an airplane be >built without a battery? Sure. There is a large Russian airplane >that can be parked all Winter, then started with the compressed air >stored from a previous flight. If it doesn't start, you have your >prisoners hand-pump in more compressed air. The first time I saw the B-57 Canberra, it was preparing to leave an air show at McConnell AFB http://www.b-57canberra.org/b-57sounds.htm Those were late 40s engines too. It was amazing to think that a thing which made so much smoke and noise was doing all that because it was the best-they-knew-how-to- do at the time. Other airplanes have used a variety of energy sources for engine cranking. I was once invited to crank up the flywheel on the engine for getting it started without success. It's not mean task. Our J-3 at 1K1 would start on the first pull of a blade . . . IF you carried out the right combination of preparation (and had the prop clocked right on the hub). Each system left the factory having met certain design goals. Those goals might be driven by some combination of customer specs, weight, costs, space, etc. Some of them caught on in the consumer markets, others were relegated to the annals of historical curiosities. >So having a battery is convenient for starting the airplane, and >seems to be a stabilizing load for the alternator. I think we've discussed and demonstrated that batteries are not "stabilizers" in the common sense of the word. The battery will assist a wound field alternator in getting started. However, the alternator doesn't need the battery to provide useful output. They will run self-excited as long as you don't hit the machine with a hi inrush load that exceeds it's output current rating thus stalling it. At Cessna in 1967 or so, we fiddled with ways to kick start alternators on the 337 should the battery become unavailable. Ideas included (1) array of D-cells OR (2) a 3-phase rectifier off the tach generator. These small energy sources could be tapped by means of a panel mounted push button to get the alternators on-line. They were operated in parallel with one regulator. Neither idea made it to production as I recall. We were sandbagging a failure that was very low on the ladder of probability. That was about 20 years before the idea of a dual feed e-bus blossomed. THAT would have been a very simple, low cost alternative to the dragons of the day. > If the battery is disconnected, plan on some other stabilization > for the alternator, because what comes out of the alternator is a > bumpy DC whose bumps are proportional the the alternator RPM. Have you ever put a 'scope on the bus of your car, started the engine, and taken trace pictures of the battery-connected versus battery disconnected? I was hard pressed to see any differences. System load had more effect on noise than the presence of a battery. I'd like to put a spectrum analyzer on the system sometime and get some real numbers. > Modern electronics are perfectly capable of doing this as well as > a big battery, but modern electronics are going to POL > (Point-of-Load), where the "main" power supply is no longer forced > to provide various voltages at various currents and various > stabilities. Instead a single (and perhaps higher voltage) power > line runs around the aircraft, and is then changed at the load to > whatever the load needs by tiny little ICs. This has advantages > from several angles, perhaps the main one being that the system > supply and buses don't easily become obsolete. What supplies and busses have or are becoming obsolete? Especially those which have or currently find favor in small airplanes? What are the design goals driving that "obsolescence"? Do these proposed technologies portend lower cost, higher reliability, less weight, increased performance? I recall visiting a booth at OSH about 15 years ago where the proprietor was demonstrating an advanced power distribution and control system. He had a control box with switches on it for nav, strobe, landing and taxi lights. One power/data wire came out of the box and ran to each of those fixtures. Digital data was transmitted to smart controllers over the power wire to turn them on/off. What could be simpler? One wire does it all. The implications for single points of failure, increased parts count, increased cost of ownership, etc were profound. I didn't see him there the next year. I have perhaps a dozen tools that will set a nail or stable style fastener. Some electric, some air driven. But sometimes the best way to drive a nail is with a hammer. Hammers have been around for a long time. >In my little airplane a-building, I plan an internally-regulated ND >alternator and a power filter using a capacitor, and inductor, Zener >and just a few other parts to give far better filtering than >standard Cessnas. Why this is not routine practice mystifies me. In what way? Cars, trucks and all manner of ground based vehicle have been doing these things for over 100 years to the tunes of hundreds of millions of examples. Airplanes to hundreds of thousands of examples. Is it your assertion that the designers of these vehicles have stubbed their intellectual toes and failed to exploit some process that promises improved performance at lower costs of ownership? As you fly along in any airplane of any age, are you painfully aware of some deficiency of performance that cries out for a quieter bus. >I might also find a reason to put in a 1.0 F supercapacitor sitting >on my shelf. Such a reason might be that it would reduce the wire >size between my battery and the starter, while (it has been shown) >cause the battery life to soar. Haven't heard of that one. Can you enlighten us as to the simple-ideas in physics that support these assertions? 1 Farad hit with a 100A load discharges at 100 volts per second. This means that the capacitor will support the battery for something on the order of 30 milliseconds after onset of a start cycle. How is this beneficial to battery life? Bob . . .


    Message 7


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 02:19:19 PM PST US
    Subject: Regulator How Hot
    From: "rvg8tor" <rvg8tor@comcast.net>
    I am planning to use the SD-20 as a back up power source, I have created an Electronic Equipment Bay out of the lower portion of the RV-8A forward baggage area. My battery is there, Hot battery bus and ground tabs. I have also installed the regulator for also SD-20 in this compartment. A friend asked how hot will that stuff get and I did not have an answer. The SD-20 regulator has a set point below normal bus voltage so it should only come on if the main alternator goes bad or is turned off, so with the regulator essentially at idle will it produce much heat, at the same token if operating on standby alternator, how hot will the regulator get. Thanks for any help. -------- Mike &quot;Nemo&quot; Elliott RV-8A QB (Fuselage) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=325485#325485


    Message 8


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 04:36:17 PM PST US
    Subject: Re: is battery filter or dead weight?
    From: "Eric M. Jones" <emjones@charter.net>
    > Haven't heard of that one. Can you enlighten us > as to the simple-ideas in physics that support > these assertions? 1 Farad hit with a 100A load > discharges at 100 volts per second. This means > that the capacitor will support the battery for > something on the order of 30 milliseconds after > onset of a start cycle. How is this beneficial > to battery life? Batteries are electrochemical are are thus affected by temperature. SuperCaps, being electrostatic have no such problem. Thus they are fastened near the starter and help immensely starting engines in cold climates, or with weak batteries one might suppose. Starting an engine is usually separated into three phases: Breakaway, takes the greatest current as the starter overcomes the static friction of the cold engine. A SuperCap helps enormously in this breakaway and load shares with current from the battery, albiet for a short time. Nobody said the initial current was 100A. In fact the SuperCap has the ability to discharge much faster than the battery--they are very low ESR. In my earlier life a problematic solenoid attached to a limited supply would just have a capacitor attached to it (and a diode and a resistor to discharge it fast and recharge it slowly) so that the capacitor would dump current through the coil. The plan I mentioned is similar. But hey, nobody said I suggest this for everyone. But I just might do it. -------- 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=325497#325497


    Message 9


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 05:33:44 PM PST US
    Subject: Re: Questions about the 9005 Low Voltage Module
    From: Jared Yates <email@jaredyates.com>
    That's great information, thank you for your help! I found the Digikey invoice and I think I might have ordered the wrong part. The national part is the Digikey LM285Z-2.5-ND http://www.national.com/ds/LM/LM185-2.5.pdf The one that I ordered is made by ON Semiconductor, Digikey LM285Z-2.5GOS-ND. http://www.onsemi.com/pub_link/Collateral/LM285-D.PDF I installed it with the flat side oriented as in the pictures, but didn't bother to check the spec sheets. National numbers the pins from right to left, as you pictured below. The ON Numbers them from left to right. The symbology with regards to the shape of the device seems to be the same between the two, so I'm not sure if the pin numbers are related to function or not. Now that I look at the descriptions, the ON is called a "DIODE REG MICROPWR 2.5V TO-92" while the National is called "IC VOLT REF MICROPWR 2.5V TO92-3." Does it look like that inadvertent substitution would be responsible here? In the worst case, I can order one of the National parts and execute the "snip and swap" as you describe. On Mon, Jan 3, 2011 at 9:31 AM, Robert L. Nuckolls, III < nuckolls.bob@aeroelectric.com> wrote: > At 07:57 AM 1/2/2011, you wrote: > > Thanks Bob! Here are the readings that I get. Battery Voltage this > morning is 12.3. > > U107 Pin 1: 0 > U107 Pin 2: 2.38 > U107 Pin 3: .68 > U107 Pin 4: 0 > U107 Pin 7: 11.24 > U107 Pin 8: 11.49 > > U110 Pin 1: 0 > U110 Pin 2: 10.77 > U110 Pin 3: 0 > U110 Pin 4: 11.49 > U110 Pin 5: 7.66 > U110 Pin 6: 10.78 > U110 Pin 8: 11.49 > > > Okay, all of the voltages you've measured are expected > values with one exception. Pin 3 of U107 voltage is > established by the voltage reference Z103 and SHOULD > be within 30 millivolts or so of 2.50 volts. > > http://www.national.com/ds/LM/LM185-2.5.pdf > > The fact that you're reading only .68 volts suggests > that Z013 is installed wrong. See data sheet for pinout > orientation . . . > > [image: Emacs!] > > Note that the image is a BOTTOM view > of the device. The pictures for assembly of > the 9005 show the flat side of the device > pointed toward the power transistor location. > > If you determine that the device IS > installed wrong you should consider the > best way to replace it. If you have the tools > and experience to removed parts from a plated > thru hole board, you have a high probability > of re-using the original part. > > I very seldom pull a part off a board with > any notion of reusing it. The value of the > part is usually pretty small compared to the > value of the whole. I usually clip the leads > on the part to be removed so that they can > be taken out of the holes one at a time thus > minimizing hazard to the board. > > > Bob . . . >


    Message 10


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 07:09:01 PM PST US
    From: "Richard E. Tasker" <retasker@optonline.net>
    Subject: Re: Questions about the 9005 Low Voltage Module
    Functionally, these are exactly the same parts. For some reason they chose to number the pins just the opposite of each other. However, if you installed it so that the flat is in the same orientation they would operate exactly the same. If you installed it based on the pin numbering, then that would be a problem. Dick Tasker Jared Yates wrote: > That's great information, thank you for your help! I found the > Digikey invoice and I think I might have ordered the wrong part. > The national part is the Digikey LM285Z-2.5-ND > http://www.national.com/ds/LM/LM185-2.5.pdf > The one that I ordered is made by ON Semiconductor, Digikey > LM285Z-2.5GOS-ND. > http://www.onsemi.com/pub_link/Collateral/LM285-D.PDF > I installed it with the flat side oriented as in the pictures, but > didn't bother to check the spec sheets. National numbers the pins > from right to left, as you pictured below. The ON Numbers them from > left to right. The symbology with regards to the shape of the device > seems to be the same between the two, so I'm not sure if the pin > numbers are related to function or not. Now that I look at the > descriptions, the ON is called a "DIODE REG MICROPWR 2.5V TO-92" while > the National is called "IC VOLT REF MICROPWR 2.5V TO92-3." Does it > look like that inadvertent substitution would be responsible here? In > the worst case, I can order one of the National parts and execute the > "snip and swap" as you describe. > > On Mon, Jan 3, 2011 at 9:31 AM, Robert L. Nuckolls, III > <nuckolls.bob@aeroelectric.com <mailto:nuckolls.bob@aeroelectric.com>> > wrote: > > At 07:57 AM 1/2/2011, you wrote: >> Thanks Bob! Here are the readings that I get. Battery Voltage >> this morning is 12.3. >> >> U107 Pin 1: 0 >> U107 Pin 2: 2.38 >> U107 Pin 3: .68 >> U107 Pin 4: 0 >> U107 Pin 7: 11.24 >> U107 Pin 8: 11.49 >> >> U110 Pin 1: 0 >> U110 Pin 2: 10.77 >> U110 Pin 3: 0 >> U110 Pin 4: 11.49 >> U110 Pin 5: 7.66 >> U110 Pin 6: 10.78 >> U110 Pin 8: 11.49 > > Okay, all of the voltages you've measured are expected > values with one exception. Pin 3 of U107 voltage is > established by the voltage reference Z103 and SHOULD > be within 30 millivolts or so of 2.50 volts. > > http://www.national.com/ds/LM/LM185-2.5.pdf > > The fact that you're reading only .68 volts suggests > that Z013 is installed wrong. See data sheet for pinout > orientation . . . > > Emacs! > > Note that the image is a BOTTOM view > of the device. The pictures for assembly of > the 9005 show the flat side of the device > pointed toward the power transistor location. > > If you determine that the device IS > installed wrong you should consider the > best way to replace it. If you have the tools > and experience to removed parts from a plated > thru hole board, you have a high probability > of re-using the original part. > > I very seldom pull a part off a board with > any notion of reusing it. The value of the > part is usually pretty small compared to the > value of the whole. I usually clip the leads > on the part to be removed so that they can > be taken out of the holes one at a time thus > minimizing hazard to the board. > > > 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 11


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 07:27:35 PM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: is battery filter or dead weight?
    Batteries are electrochemical and thus affected by temperature. SuperCaps, being electrostatic have no such problem. Thus they are fastened near the starter and help immensely starting engines in cold climates, or with weak batteries one might suppose. I'm having trouble calibrating "immensely" . . . Starting an engine is usually separated into three phases: Breakaway, takes the greatest current as the starter overcomes the static friction of the cold engine. A SuperCap helps enormously in this breakaway and load shares with current from the battery, albiet for a short time. Nobody said the initial current was 100A. In fact the SuperCap has the ability to discharge much faster than the battery--they are very low ESR. Absolutely . . . but while capacitors have a greater ability to deliver CURRENT, their ability to deliver ENERGY is the fact I'm wrestling with. Total energy stored on a 1F capacitor at 12v is CE(squared)/2 or 72 watt-seconds. The capacitor can deliver energy into the cranking task only until its terminal voltage drops to some value equal to the battery terminal voltage . . . lets assume a cold weather worst case of 8v whereupon the capacitor still contains 1*8^2/2 or 32 watt-seconds. Hence, the paralleled capacitor can offer 40 watt-seconds of stored energy to the task of getting the engine started for about 50 milliseconds topes . . . . Assume 100A (small engine) and 9 volts average for 10 seconds gives 100 * 9 * 10 = 9000 watt-seconds. So perhaps we see the capacitor contributing less than 1/2 of 1% into the first 1/20 of a second of a cranking scenario. Does this agree with your calibration of "immensely"? In my earlier life a problematic solenoid attached to a limited supply would just have a capacitor attached to it (and a diode and a resistor to discharge it fast and recharge it slowly) so that the capacitor would dump current through the coil. The plan I mentioned is similar. But of course . . . you're getting a boost for the purposes of aiding an event that takes perhaps 10 milliseconds total and a current level on the order of tens of amps . . . not ten seconds for hundreds of amps. These are not similar energy transfer scenarios. But hey, nobody said I suggest this for everyone. But I just might do it. Understand. You brought forth an idea that suggested "soaring battery life" . . . I'm just making sure I've not overlooked some new discovery. Bob . . .


    Message 12


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 10:23:34 PM PST US
    From: Tim Andres <tim2542@sbcglobal.net>
    Subject: CPC's
    I saw a interesting video tonight from EAA on using circular plastic connectors. http://www.eaavideo.org/video.aspx?v=713328494001 Can anyone tell me the part numbers for the connectors he's using? I'd like to use these for the stick grips and a few other places. I would like to use the same crimp pins he's using instead of the molex type, which is about all I could find on a search tonight. Thanks, Tim Andres


    Message 13


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 11:09:35 PM PST US
    From: "Don" <dsvs@ca.rr.com>
    Subject: CPC's
    That is a Danials crimper and the pins and sockets are machined . Steinair has both. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Tim Andres Sent: Monday, January 03, 2011 10:14 PM Subject: AeroElectric-List: CPC's I saw a interesting video tonight from EAA on using circular plastic connectors. http://www.eaavideo.org/video.aspx?v=713328494001 Can anyone tell me the part numbers for the connectors he's using? I'd like to use these for the stick grips and a few other places. I would like to use the same crimp pins he's using instead of the molex type, which is about all I could find on a search tonight. Thanks, Tim Andres


    Message 14


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 11:31:00 PM PST US
    From: Werner Schneider <glastar@gmx.net>
    Subject: Re: CPC's
    This are from Tycoelectronics: <http://www.tycoelectronics.com/catalog/minf/en/645> and here 493 products: <http://www.tycoelectronics.com/catalog/feat/en/c/10574?BML=10576,17560,23645,17584,17760> bulkier then the db9 I use but if you need more then 9 pins they might be your choice. Werner > Can anyone tell me the part numbers for the connectors he's using? I'd > like to use these for the stick grips and a few other places. I would


    Message 15


  • INDEX
  • Back to Main INDEX
  • PREVIOUS
  • Skip to PREVIOUS Message
  • NEXT
  • Skip to NEXT Message
  • LIST
  • Reply to LIST Regarding this Message
  • SENDER
  • Reply to SENDER Regarding this Message
    Time: 11:43:50 PM PST US
    From: "Don" <dsvs@ca.rr.com>
    Subject: CPC's
    Pins and sockets are on allied electronics catalog page 202 use DM20 p and s. Series 2 connectors are on page 199 -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Don Sent: Monday, January 03, 2011 11:07 PM Subject: RE: AeroElectric-List: CPC's That is a Danials crimper and the pins and sockets are machined . Steinair has both. -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Tim Andres Sent: Monday, January 03, 2011 10:14 PM Subject: AeroElectric-List: CPC's I saw a interesting video tonight from EAA on using circular plastic connectors. http://www.eaavideo.org/video.aspx?v=713328494001 Can anyone tell me the part numbers for the connectors he's using? I'd like to use these for the stick grips and a few other places. I would like to use the same crimp pins he's using instead of the molex type, which is about all I could find on a search tonight. Thanks, Tim Andres




    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
  • 7-Day List Browse
  •   http://www.matronics.com/browse/aeroelectric-list
  • Browse AeroElectric-List 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.

    -- Please support this service by making your Contribution today! --