AeroElectric-List Digest Archive

Thu 08/15/13


Total Messages Posted: 15



Today's Message Index:
----------------------
 
     1. 12:33 AM - Re: AeroElectric-List Digest: 5 Msgs - 08/14/13 (Franz Fux)
     2. 08:37 AM - Failed brownout battery experiment (user9253)
     3. 09:28 AM - Re: Failed brownout battery experiment (Charlie England)
     4. 09:39 AM - Re: Failed brownout battery experiment (Robert L. Nuckolls, III)
     5. 10:05 AM - Re: Failed brownout battery experiment (Robert L. Nuckolls, III)
     6. 10:52 AM - Re: Failed brownout battery experiment (Ed)
     7. 11:00 AM - Re: Failed brownout battery experiment (Robert L. Nuckolls, III)
     8. 11:40 AM - Re: Failed brownout battery experiment (Jared Yates)
     9. 01:27 PM - Re: Failed brownout battery experiment (Charlie England)
    10. 01:36 PM - Re: Failed brownout battery experiment (Jared Yates)
    11. 04:10 PM - Re: Failed brownout battery experiment (Robert L. Nuckolls, III)
    12. 06:30 PM - Re: Failed brownout battery experiment (user9253)
    13. 08:04 PM - Re: Re: Failed brownout battery experiment (Robert L. Nuckolls, III)
    14. 08:30 PM - Re: Re: Failed brownout battery experiment (Ken)
    15. 08:57 PM - Re: Re: Failed brownout battery experiment (Robert L. Nuckolls, III)
 
 
 


Message 1


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    Time: 12:33:17 AM PST US
    From: "Franz Fux" <franz@lastfrontierheli.com>
    Subject: Re: AeroElectric-List Digest: 5 Msgs - 08/14/13
    unable to respond to any mail until the 20th of August,


    Message 2


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    Time: 08:37:18 AM PST US
    Subject: Failed brownout battery experiment
    From: "user9253" <fransew@gmail.com>
    The backup battery died for my Dynon D-180. My RV-12 is used for day VFR only. A backup battery is not a necessity. Instead of paying Dynon $130 every couple of years for a new backup battery, I thought of an alternative brownout circuit to prevent the D-180 from rebooting during engine start. Not wanting to add the weight of a 7ah lead acid battery, I decided to use a couple of AA batteries. I tapped into the load side of the start switch and connected to an AA battery holder, then to the External Backup Power input pin 15 on the back of the Dynon. I figured that 3 volts from the AA batteries in series with the aricraft's 8 volts during engine start would provide the Dynon with 11 volts, one volt above the minimum required. As you might have guessed, the experiment failed. The Dynon still reboots during engine start. Evidently the AA cells are unable to maintain their voltage and supply 1.5 amps for a couple of seconds during engine start. Should I repeat the experiment using "D" cells? Or is the whole idea flawed? Comments and suggestions appreciated. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=406766#406766


    Message 3


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    Time: 09:28:26 AM PST US
    From: Charlie England <ceengland7@gmail.com>
    Subject: Re: Failed brownout battery experiment
    On 08/15/2013 10:36 AM, user9253 wrote: > > The backup battery died for my Dynon D-180. My RV-12 is used for day V FR only. A backup battery is not a necessity. Instead of paying Dynon $ 130 every couple of years for a new backup battery, I thought of an alter native brownout circuit to prevent the D-180 from rebooting during engine start. Not wanting to add the weight of a 7ah lead acid battery, I deci ded to use a couple of AA batteries. I tapped into the load side of the start switch and connected to an AA battery holder, then to the External Backup Power input pin 15 on the back of the Dynon. I figured that 3 vol ts from the AA batteries in series with the aricraft's 8 volts during eng ine start would provide the Dynon with 11 volts, one volt above the minim um required. As you might have guessed, the experiment failed. The Dyno n still reboots during engine start. Evidently the AA cells are unable t o maintain their voltage and supply 1.5 amps for a couple of seconds duri ng engine start. Should I repeat the expe! > riment using "D" cells? Or is the whole idea flawed? > Comments and suggestions appreciated. > Joe > > -------- > Joe Gores > > Short answer: that (series connection of the AA's) won't work. You could insert them in place of the original backup battery, but the Dynon backup is recharged constantly by the plane's supply during normal operation. http://www.dynonavionics.com/docs/D180_Feature_Battery.html This means that the AA's will have charging voltage applied to them constantly, & you'll likely have an acidic mess in the D-180 fairly quickly. How about bringing the backup power terminals outside the unit, & making up a Ni-MH battery pack with the same voltage/AH rating as the Li-ion pack? It would be a bit larger & heavier, but nothing like a lead-acid battery. And really inexpensive. Charlie <http://www.dynonavionics.com/docs/D180_Feature_Battery.html>


    Message 4


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    Time: 09:39:55 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Failed brownout battery experiment
    At 10:36 AM 8/15/2013, you wrote: > >The backup battery died for my Dynon D-180. My RV-12 is used for >day VFR only. A backup battery is not a necessity. Instead of >paying Dynon $130 every couple of years for a new backup battery, I >thought of an alternative brownout circuit to prevent the D-180 from >rebooting during engine start. Not wanting to add the weight of a >7ah lead acid battery, I decided to use a couple of AA batteries. I >tapped into the load side of the start switch and connected to an AA >battery holder, then to the External Backup Power input pin 15 on >the back of the Dynon. I figured that 3 volts from the AA batteries >in series with the aricraft's 8 volts during engine start would >provide the Dynon with 11 volts, one volt above the minimum >required. As you might have guessed, the experiment failed. The >Dynon still reboots during engine start. Evidently the AA cells are >unable to maintain their voltage and supply 1.5 amps for a couple of >seconds during engine start. Should I repeat the experiment using >"D" cells? Or is the whole idea flawed? >Comments and suggestions appreciated. >Joe The 'brown out' event is just a few hundred milliseconds long. Also, without the knowledge afforded by schematics and/or design goals for performance of the back-up battery power input pin, the precise cause for the failure is unknown. How low can the battery back up pin go and still support the dynon over the duration of a brown-out transient? Does the back up battery pin draw any current when the ship's power is OFF? In other words, what conditions must exist to relieve the back-up battery pin of any load? What is the load current demand on a back-up battery? You can explore these questions with an adjustable power supply hooked to the back-up battery pin. Bob . . .


    Message 5


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    Time: 10:05:21 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Failed brownout battery experiment
    > > The 'brown out' event is just a few hundred milliseconds > long. See http://tinyurl.com/pyszrmf Bob . . .


    Message 6


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    Time: 10:52:09 AM PST US
    From: Ed <decaclops@gmail.com>
    Subject: Re: Failed brownout battery experiment
    Or just pull the breaker, (if you have one), for the Dynon and close it after engine start. That's what I've been doing with a D-10 for years. Ed Holyoke On 8/15/2013 9:27 AM, Charlie England wrote: > On 08/15/2013 10:36 AM, user9253 wrote: >> >> The backup battery died for my Dynon D-180. My RV-12 is used for day VFR only. A backup battery is not a necessity. Instead of paying Dynon $130 every couple of years for a new backup battery, I thought of an alternative brownout circuit to prevent the D-180 from rebooting during engine start. Not wanting to add the weight of a 7ah lead acid battery, I decided to use a couple of AA batteries. I tapped into the load side of the start switch and connected to an AA battery holder, then to the External Backup Power input pin 15 on the back of the Dynon. I figured that 3 volts from the AA batteries in series with the aricraft's 8 volts during engine start would provide the Dynon with 11 volts, one volt above the minimum required. As you might have guessed, the experiment failed. The Dynon still reboots during engine start. Evidently the AA cells are unable to maintain their voltage and supply 1.5 amps for a couple of seconds during engine start. Should I repeat the ex pe! >> >> riment using "D" cells? Or is the whole idea flawed? >> Comments and suggestions appreciated. >> Joe >> >> -------- >> Joe Gores >> >> > Short answer: that (series connection of the AA's) won't work. > > You could insert them in place of the original backup battery, but the > Dynon backup is recharged constantly by the plane's supply during > normal operation. > http://www.dynonavionics.com/docs/D180_Feature_Battery.html > This means that the AA's will have charging voltage applied to them > constantly, & you'll likely have an acidic mess in the D-180 fairly > quickly. > > How about bringing the backup power terminals outside the unit, & making > up a Ni-MH battery pack with the same voltage/AH rating as the Li-ion > pack? It would be a bit larger & heavier, but nothing like a lead-acid > battery. And really inexpensive. > > Charlie > <http://www.dynonavionics.com/docs/D180_Feature_Battery.html> > > * > > > * >


    Message 7


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    Time: 11:00:36 AM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Failed brownout battery experiment
    >Short answer: that (series connection of the AA's) won't work. > >You could insert them in place of the original backup battery, but >the Dynon backup is recharged constantly by the plane's supply >during normal operation. ><http://www.dynonavionics.com/docs/D180_Feature_Battery.html>http://www.dynonavionics.com/docs/D180_Feature_Battery.html > >This means that the AA's will have charging voltage applied to them >constantly, & you'll likely have an acidic mess in the D-180 fairly quickly. > >How about bringing the backup power terminals outside the unit, & >making up a Ni-MH battery pack with the same voltage/AH rating as >the Li-ion pack? It would be a bit larger & heavier, but nothing >like a lead-acid battery. And really inexpensive. Good input Charlie, If it's a lithium battery that's being replaced, then an array of 4 lithium cells could be fabricated to put in place of the factory product. In fact, if one tears a Dynon battery apart, the picture on the website suggests that the cell pack is made form four of these guys . . . http://tinyurl.com/krgpjtx So it seems that for about $16 you could refurbish the original pack . . . Referring to the D180_IM we read: [backup battery] Will operate the FlightDEK-D180 only if Master Power is not present. The transition from Master Power to External Backup Power will bring up a warning, requiring you to press ACK within 30 seconds to keep the unit operating. This warning will also display when transitioning from either Master or External Backup to Internal Battery power. This sounds like a free floating input from an external power source that is not intended to be charged from within the D180 nor is it loaded unless main power is missing and limited to 30 seconds of loading unless acknowledged by pilot input. So an external battery on the order of 10-14 volts will probably secure satisfactory brown-out performance. If a DIY refurb of internal battery using off the shelf, tabbed cells is not a option, then an external pak of cells tied to the bus through a series diode and perhaps a 200 ohms (limit charging current to very low value) would take care of brown-out events. This external pack might be 4 lithium cells or maybe 8 Ni-Mh cells intended to be (1) used hundreds of milliseconds per flight and (2) very lightly charged from the bus. Bob . . .


    Message 8


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    Time: 11:40:21 AM PST US
    Subject: Re: Failed brownout battery experiment
    From: Jared Yates <email@jaredyates.com>


    Message 9


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    Time: 01:27:07 PM PST US
    From: Charlie England <ceengland7@gmail.com>
    Subject: Re: Failed brownout battery experiment
    On 08/15/2013 01:00 PM, Robert L. Nuckolls, III wrote: >> Short answer: that (series connection of the AA's) won't work. >> >> You could insert them in place of the original backup battery, but >> the Dynon backup is recharged constantly by the plane's supply >> during normal operation. >> http://www.dynonavionics.com/docs/D180_Feature_Battery.html >> <http://www.dynonavionics.com/docs/D180_Feature_Battery.html> > >> This means that the AA's will have charging voltage applied to them >> constantly, & you'll likely have an acidic mess in the D-180 fairly >> quickly. >> >> How about bringing the backup power terminals outside the unit, & >> making up a Ni-MH battery pack with the same voltage/AH rating as the >> Li-ion pack? It would be a bit larger & heavier, but nothing like a >> lead-acid battery. And really inexpensive. > > Good input Charlie, > > If it's a lithium battery that's being replaced, > then an array of 4 lithium cells could be fabricated > to put in place of the factory product. In fact, > if one tears a Dynon battery apart, the picture > on the website suggests that the cell pack is > made form four of these guys . . . > > http://tinyurl.com/krgpjtx <http://tinyurl.com/krgpjtx> > > So it seems that for about $16 you could refurbish > the original pack . . . > > Referring to the D180_IM we read: > > *[backup battery] Will operate the FlightDEK-D180 only if Master > Power is not present. The transition from Master > Power to External Backup Power will bring up a > warning, requiring you to press ACK within 30 > seconds to keep the unit operating. This warning will > also display when transitioning from either Master or > External Backup to Internal Battery power. > > * This sounds like a free floating input from an > external power source that is not intended to be charged > from within the D180 nor is it loaded unless > main power is missing and limited to 30 seconds > of loading unless acknowledged by pilot input. > > So an external battery on the order of 10-14 > volts will probably secure satisfactory brown-out > performance. If a DIY refurb of internal battery > using off the shelf, tabbed cells is not a option, > then an external pak of cells tied to the > bus through a series diode and perhaps a 200 > ohms (limit charging current to very low value) > would take care of brown-out events. This external > pack might be 4 lithium cells or maybe 8 Ni-Mh > cells intended to be (1) used hundreds of milliseconds > per flight and (2) very lightly charged from > the bus. > > Bob . . . > > *From the same web page: * > The battery and charging circuitry are conveniently encased within the > EFIS itself and automatically charge that battery anytime external > power is applied. Charlie


    Message 10


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    Time: 01:36:49 PM PST US
    Subject: Re: Failed brownout battery experiment
    From: Jared Yates <email@jaredyates.com>
    Well, maybe the little circuit does something else... Charging was just a logical guess on my part. On Thu, Aug 15, 2013 at 4:25 PM, Charlie England <ceengland7@gmail.com> wrote: > On 08/15/2013 01:00 PM, Robert L. Nuckolls, III wrote: > > Short answer: that (series connection of the AA's) won't work. > > You could insert them in place of the original backup battery, but the Dynon > backup is recharged constantly by the plane's supply during normal > operation. > http://www.dynonavionics.com/docs/D180_Feature_Battery.html > > > This means that the AA's will have charging voltage applied to them > constantly, & you'll likely have an acidic mess in the D-180 fairly quickly. > > How about bringing the backup power terminals outside the unit, & making up > a Ni-MH battery pack with the same voltage/AH rating as the Li-ion pack? It > would be a bit larger & heavier, but nothing like a lead-acid battery. And > really inexpensive. > > > Good input Charlie, > > If it's a lithium battery that's being replaced, > then an array of 4 lithium cells could be fabricated > to put in place of the factory product. In fact, > if one tears a Dynon battery apart, the picture > on the website suggests that the cell pack is > made form four of these guys . . . > > http://tinyurl.com/krgpjtx > > So it seems that for about $16 you could refurbish > the original pack . . . > > Referring to the D180_IM we read: > > [backup battery] Will operate the FlightDEK-D180 only if Master > Power is not present. The transition from Master > Power to External Backup Power will bring up a > warning, requiring you to press ACK within 30 > seconds to keep the unit operating. This warning will > also display when transitioning from either Master or > External Backup to Internal Battery power. > > This sounds like a free floating input from an > external power source that is not intended to be charged > from within the D180 nor is it loaded unless > main power is missing and limited to 30 seconds > of loading unless acknowledged by pilot input. > > So an external battery on the order of 10-14 > volts will probably secure satisfactory brown-out > performance. If a DIY refurb of internal battery > using off the shelf, tabbed cells is not a option, > then an external pak of cells tied to the > bus through a series diode and perhaps a 200 > ohms (limit charging current to very low value) > would take care of brown-out events. This external > pack might be 4 lithium cells or maybe 8 Ni-Mh > cells intended to be (1) used hundreds of milliseconds > per flight and (2) very lightly charged from > the bus. > > Bob . . . > > > From the same web page: > > The battery and charging circuitry are conveniently encased within the EFIS > itself and automatically charge that battery anytime external power is > applied. > > > Charlie > >


    Message 11


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    Time: 04:10:07 PM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Failed brownout battery experiment
    > > >>The battery and charging circuitry are conveniently encased within >>the EFIS itself and automatically charge that battery anytime >>external power is applied. > >Charlie The opening thought for this thread was to search out an alternative to the expensive, built-in battery. If it can be cloned from stock cells, then that would be the obvious $low$ move. If not, then an external battery from li-ion or ni-mh with a trickle charge circuit would be a second choice. Doing the system integration to pin 15 was the unknown task . . . Bob . . .


    Message 12


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    Time: 06:30:48 PM PST US
    Subject: Re: Failed brownout battery experiment
    From: "user9253" <fransew@gmail.com>
    The Dynon D-180 has 3 power inputs, the Master Power input on pin 1, External Backup Power on pin 15, and internal backup power using Dynon's proprietary Li-Ion $130 battery. Pins 1 and 15 require between 10 and 30 volts. The D-180 draws about 1.5 amps. If voltage is available on pin 1, then the D-180 will not use power from pin 15. No power is used from either input when the unit is turned off. There is an alarm if power fails on pin 1. But the alarm will silence automatically when power is restored on pin 1. During engine start, the pilot never sees that alarm because it is only there for a millisecond. After the internal battery failed, I thought the same as Bob suggested: Buy 4 Li-Ion cells off eBay to replace the original ones. It seemed like a simple and inexpensive solution until the new cells arrived in the mail and I tried replacing the old ones. There is more to the battery pack than just batteries. There is a circuit board about 1/2" x 2" that is glued to the batteries. Evidently this circuit board monitors the voltage on each cell and charges each cell individually rather then treating all 4 cells as a single battery. After all, these are Li-Ion cells that could cause a fire if not charged properly. Normally I would never work on an electronic circuit with the power turned on. But one can not turn off a battery. Who knows if I damaged the circuit board by soldering live wires onto it in random sequence? Another problem is that the battery compartment opening is just barely big enough to slide Dynon's battery pack in. Just a few extra thousandths and the battery will not slide into the opening. Of course my battery pack was too high to go in. I took off some of the electrical tape and did manage to force it in. But being worried about cells shorting out to the metal enclosure, I took my batteries out and abandoned the idea. Why take a chance on a fire caused by my homemade Li-Ion battery pack? Running the internal battery wires and plug outside of the case is not an option because the battery compartment door is on the side of the case and blocked by the D-180 mounting tray. As Charlie pointed out, the internal battery cable puts out a charging voltage. I did not want to connect another type of battery to that. So I decided to use pin 15, the External Battery input which does not receive a charging voltage from the D-180. And it is accessible on the back of the case. I could just leave the D-180 turned off during engine start as Ed suggested. But I like having it on to give the altimeter time to stabilize. And monitoring electric fuel pump pressure is part of the pre-start checklist. One concern that I have with alkaline batteries in series with the start contactor supply is that the arc suppression diode on the starter contactor is forward biased to my alkaline batteries. But my batteries did not discharge after 24 hours. I will continue to experiment and post my results. Joe -------- Joe Gores Read this topic online here: http://forums.matronics.com/viewtopic.php?p=406818#406818


    Message 13


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    Time: 08:04:02 PM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Failed brownout battery experiment
    At 08:28 PM 8/15/2013, you wrote: > >The Dynon D-180 has 3 power inputs, the Master Power input on pin 1, >External Backup Power on pin 15, and internal backup power using >Dynon's proprietary Li-Ion $130 battery. Pins 1 and 15 require >between 10 and 30 volts. The D-180 draws about 1.5 amps. Okay, this means that 1 and 15 feed a switchmode power supply. This will be a constant wattage input of 14w max according to the manual. So an 18-pack of AA alkaline cells as a backup battery would offer a backup supply of 27 volts which would be loaded to the tune of 0.5A max for the few milliseconds of brownout. This figure is well within the capability of an AA alkaline. Given that the pak is loaded for hundreds of milliseconds once each flight, the battery pack service life should be measurable in years. Since it's only intended to provide brown-out mitigation, then you have no risk of latent failure going unnoticed before flight. Evidently this circuit board monitors the voltage on each cell and charges each cell individually rather then treating all 4 cells as a single battery. Yup, just about everybody is doing smart batteries when populated with li-ion cells. Given that you never plan to run these things down, they'll only need to support the brown-out transient. So a series array trickle charged through a resistor is not even going to warm up. In fact, you'd probably want to use only 3 cells so that you can produce a nearly constant current through a resistor. Say the cranking transient draws 1.5A at 11 volts from a string of 3 cells for 500 milliseconds. That's about 7J of energy max. Okay, assume 80% charging efficiency so over the next hour, you'll want to stuff about 10J back into the cells. 10J at 10v for in 1 second is about 1 amp of recharge current. For one hour, it's 1/3600 or 277 microamps! I suspect these cells would not be seriously insulted with say, 1 milliamp of 100% duty cycle trickle charge, so a 5K resistor with a diode in series to prevent back feed would offer a top-off-trickle charge to the array. A similar approach could be considered for ni-mh array. Problem is the self-discharge rate of these cells would probably disqualify them. So a free standing AA alkaline pak or drip-charged li-ion pak seem the most viable battery options. How about an active option? A step up module like this one http://tinyurl.com/m7t78eh could be set up to supply say 19 volts to pin 15 of the Dynon, but would certainly support 14 watts for 500 milliseconds during a brown-out. You might have some RFI issues with this necessitating some filters and perhaps a metallic enclosure . . . but it's small and the price is right. Bob . . .


    Message 14


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    Time: 08:30:21 PM PST US
    From: Ken <klehman@albedo.net>
    Subject: Re: Failed brownout battery experiment
    FWIW I have a similar dc to dc converter in a plastic box running a 28v Turn & Bank instrument off 12 volts and have no RFI issues. Ken On 15/08/2013 10:58 PM, Robert L. Nuckolls, III wrote: > <nuckolls.bob@aeroelectric.com> > > At 08:28 PM 8/15/2013, you wrote: >> >> The Dynon D-180 has 3 power inputs, the Master Power input on pin 1, >> External Backup Power on pin 15, and internal backup power using >> Dynon's proprietary Li-Ion $130 battery. Pins 1 and 15 require >> between 10 and 30 volts. The D-180 draws about 1.5 amps. > > Okay, this means that 1 and 15 feed a switchmode power > supply. This will be a constant wattage input of 14w > max according to the manual. So an 18-pack of AA alkaline > cells as a backup battery would offer a backup supply of > 27 volts which would be loaded to the tune of 0.5A max > for the few milliseconds of brownout. > > This figure is well within the capability of an AA > alkaline. Given that the pak is loaded for hundreds > of milliseconds once each flight, the battery pack > service life should be measurable in years. > > Since it's only intended to provide brown-out > mitigation, then you have no risk of latent failure > going unnoticed before flight. > > Evidently this circuit board monitors the voltage on each cell and > charges each cell individually rather then treating all 4 cells as a > single battery. > > Yup, just about everybody is doing smart batteries > when populated with li-ion cells. Given that you > never plan to run these things down, they'll only > need to support the brown-out transient. So a > series array trickle charged through a resistor > is not even going to warm up. In fact, you'd > probably want to use only 3 cells so that you can > produce a nearly constant current through a resistor. > > Say the cranking transient draws 1.5A at 11 volts > from a string of 3 cells for 500 milliseconds. That's > about 7J of energy max. Okay, assume 80% charging > efficiency so over the next hour, you'll want to > stuff about 10J back into the cells. 10J at 10v > for in 1 second is about 1 amp of recharge current. > For one hour, it's 1/3600 or 277 microamps! > > I suspect these cells would not be seriously > insulted with say, 1 milliamp of 100% duty > cycle trickle charge, so a 5K resistor with > a diode in series to prevent back feed would > offer a top-off-trickle charge to the array. > > A similar approach could be considered for > ni-mh array. Problem is the self-discharge > rate of these cells would probably disqualify > them. So a free standing AA alkaline pak or > drip-charged li-ion pak seem the most viable > battery options. > > How about an active option? A step up module > like this one > > http://tinyurl.com/m7t78eh > > could be set up to supply say 19 volts to > pin 15 of the Dynon, but would certainly > support 14 watts for 500 milliseconds during > a brown-out. > > You might have some RFI issues with this > necessitating some filters and perhaps > a metallic enclosure . . . but it's > small and the price is right. > > > Bob . . . > >


    Message 15


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    Time: 08:57:25 PM PST US
    From: "Robert L. Nuckolls, III" <nuckolls.bob@aeroelectric.com>
    Subject: Re: Failed brownout battery experiment
    At 10:20 PM 8/15/2013, you wrote: > >FWIW I have a similar dc to dc converter in a plastic box running a >28v Turn & Bank instrument off 12 volts and have no RFI issues. >Ken Good data . . . thank you. Bob . . .




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