Matronics Email Lists :: View topic

Matronics Email Lists
Web Forum Interface to the Matronics Email Lists

Get Email Distribution Too! FAQ Search Memberlist Usergroups Register

Profile Log in to check your private messages Log in

alternator
Goto page 1, 2 Next

Matronics Email Lists Forum Index -> JabiruEngine-List

View previous topic :: View next topic

Author Message

BobbyPaulk(at)comcast.net
Guest

Posted: Fri Apr 24, 2015 12:05 pm Post subject: alternator

List,



I have two flights of about 30 minutes each on my Jabiru 3300 after some repairs and a couple of modifications.



I changed the Alternator coils from 2 parallel circuits to 1 series circuit in accordance with Jabiru AVDALSR-087-1. It was working fine on the first flight and most of the second flight. Output was 14.6 volts while taxiing out. Halfway thru the second flight I turned on strobe lights to put a load on the alternator. I figure I was drawing no more than 11 amps. When I reduced power to enter downwind I smelled wires burning and noticed the battery voltage was down to 12.2. I turned off the strobes and landed. 

On inspection I found every other coil ( 6 ) in the alternator burned black and the alternator no longer worked. 



I am not going back with the original magnet / stator dynamo.



My question to the list is whether to go with the CAMit alternator or the Rotec. I am leaning toward the CAMit version since they are very familiar with the Jabiru / CAMit Engine. 



Does anyone know if the belt on either one can be changed without removing the aluminum back plate?



Bobby



Zodiac 601 XL "B"

Jabiru  3300  S/N  1141

Sensenich 64" x 51" Prop

Bing Carb 260 Main & 290 Needle Jet

Status - Flying  236 hrs. 

Do Not Archive



 [quote][b]

matronics(at)rtist.nl
Guest

Posted: Fri Apr 24, 2015 12:51 pm Post subject: alternator

CAMit for sure. As you say, they know       the engine very well (they built them for many years) and today       sell new engines with just this alternator setup.

       

       The aluminium spider needs to come off to change the belt, but       that should be easy with the old alternator parts removed, and       only a once-every-500-hours job.

       

       Rob

       

       On 4/24/2015 10:04 PM, BobbyPaulk(at)comcast.net (BobbyPaulk(at)comcast.net) wrote:

     

     [quote]                List,

         

         I have two flights of about 30 minutes each on my Jabiru           3300 after some repairs and a couple of modifications.

         

         I changed the Alternator coils from 2 parallel circuits to           1 series circuit in accordance with Jabiru AVDALSR-087-1. It           was working fine on the first flight and most of the second           flight. Output was 14.6 volts while taxiing out. Halfway thru           the second flight I turned on strobe lights to put a load on           the alternator. I figure I was drawing no more than 11 amps.           When I reduced power to enter downwind I smelled wires burning           and noticed the battery voltage was down to 12.2. I turned off           the strobes and landed. 

         On inspection I found every other coil ( 6 ) in the           alternator burned black and the alternator no longer worked. 

         

         I am not going back with the original magnet / stator           dynamo.

         

         My question to the list is whether to go with the CAMit           alternator or the Rotec. I am leaning toward the CAMit version           since they are very familiar with the Jabiru / CAMit Engine. 

         

         Does anyone know if the belt on either one can be changed           without removing the aluminum back plate?

         

         

         

         Bobby

         

         Zodiac 601 XL "B"

           JabiruÂ  3300Â  S/NÂ  1141

           Sensenich 64" x 51" Prop

           Bing Carb 260 Main & 290 Needle Jet

           Status - FlyingÂ  236 hrs. 

           

           

           Do Not Archive

       

        	  Quote: 	
		  

	
     [b]

nuckollsr

Joined: 24 Mar 2009
Posts: 95
Location: Medicine Lodge, KS

Posted: Sat Apr 25, 2015 4:19 am Post subject: alternator

At 15:51 2015-04-24, you wrote:

CAMit for sure. As you say, they know the engine very well (they 

built them for many years) and today sell new engines with just this 

alternator setup.



The aluminium spider needs to come off to change the belt, but that 

should be easy with the old alternator parts removed, and only a 

once-every-500-hours job.



Rob



On 4/24/2015 10:04 PM, BobbyPaulk(at)comcast.net wrote:

List,

I have two flights of about 30 minutes each on my Jabiru 3300 after 

some repairs and a couple of modifications.

I changed the Alternator coils from 2 parallel circuits to 1 series 

circuit in accordance with Jabiru AVDALSR-087-1. It was working fine 

on the first flight and most of the second flight. Output was 14.6 

volts while taxiing out. Halfway thru the second flight I turned on 

strobe lights to put a load on the alternator. I figure I was drawing 

no more than 11 amps. When I reduced power to enter downwind I 

smelled wires burning and noticed the battery voltage was down to 

12.2. I turned off the strobes and landed.

On inspection I found every other coil ( 6 ) in the alternator burned 

black and the alternator no longer worked.

I am not going back with the original magnet / stator dynamo.

My question to the list is whether to go with the CAMit alternator or 

the Rotec. I am leaning toward the CAMit version since they are very 

familiar with the Jabiru / CAMit Engine.

Does anyone know if the belt on either one can be changed without 

removing the aluminum back plate?



   I was astounded to learn of what was touted to be

   a 'Jabiru recommendation' to series up the windings

   on the alternator for 'improved performance'.

   This has the effect of DOUBLING the alternator's

   AC output voltage . . . and yes, you'll see

   improved bus voltage readings at low rpm.



   To paraphrase the astute observation by one

   of my favorite authors, "There ain't no such

   thing as a free lunch."



   Moving from parallel connection to series

   connection doubles output voltage while

   cutting current delivery capability by more

   than 1/2.  I.e. the POWER available from the

   alternator is unchanged but delivered at

   a higher voltage with lower current capability.



   There ARE regulator designs which would exploit

   virtually ALL the ENERGY available from the

   alternator at ANY practical voltage.



   In the legacy rectifier/regulator, current

   flowing in alternator windings is a mirror

   of that flowing out of the R/R. Rewiring the alternator

   while retaining the legacy regulator is all

   but guaranteed to produce the observed results.



   Going from parallel to series COMBINED with an

   upgrade of regulator technology would be a very good

   thing to contemplate.



   I'm having trouble believing that Jabiru

   engineers made such a recommendation; I'll

   bet it came from somebody down the distribution

   chain. In any case, ill-conceived. Replacing

   the alternator with a belt-driven, automotive

   derivative is also a practical option.





Bob . . .

-----------------------------

Bob Nuckolls

AeroElectric Connection

P.O. Box 130

Medicine Lodge, KS  67104-0130

Mobile: 316-209-7528

Web: http://aeroelectric.com

------------------------------

matronics(at)rtist.nl
Guest

Posted: Sat Apr 25, 2015 9:21 am Post subject: alternator

Hello Bob,

     

     As astounding as it sounds, this mod indeed comes from the Jabiru     factory themselves. Run a search for AVDALSR87 on Google and you     will find the PDF listed as the first hit, direct from the Jabiru     site. There is a second version (AVDALSR87-2) with a bit more     explanation around, but nowhere does either version mention the loss     of current delivery capability. It just touts the ability to charge     the battery at near-idle speeds. Several people asked Jabiru about     it and they claimed no loss of power from this mod. 

     

     Considering the same current draw from the plane's electric system     and the internal losses (= heat) in the alternator coil quadrupling     at equal current draw with this mod (going from 1/2R to 2R), it is     no surprise the coil will burn up.

     

     The belt driven alternative has two positive effects. First, there's     more electrical power available, also at low idle speed. Second, the     belt drive dampens torque pulses which helps keep the flywheel bolts     intact. Definitely te way to go.

     

     Rob

     

     

     > I was astounded to learn of what was touted to be

     > a 'Jabiru recommendation' to       series up the windings on the alternator

       > for 'improved performance'. This has the effect of DOUBLING       the

       > alternator's AC output voltage . . . and yes, you'll see       improved bus

       > voltage readings at low rpm.

       > 

       > To paraphrase the astute observation by one of my favorite       authors,

       > "There ain't no such thing as a free lunch."

       > 

       > Moving from parallel connection to series connection doubles       output

       > voltage while cutting current delivery capability by more       than 1/2.

       > I.e. the POWER available from the alternator is unchanged but

       > delivered at a higher voltage with lower current capability.

       > 

       > There ARE regulator designs which would exploit virtually ALL       the

       > ENERGY available from the alternator at ANY practical       voltage.

       > 

       > In the legacy rectifier/regulator, current flowing in       alternator

       > windings is a mirror of that flowing out of the R/R. Rewiring       the

       > alternator while retaining the legacy regulator is all but       guaranteed

       > to produce the observed results.

       > 

       > Going from parallel to series COMBINED with an upgrade of       regulator

       > technology would be a very good thing to contemplate.

       > 

       > I'm having trouble believing that Jabiru engineers made such       a

       > recommendation; I'll bet it came from somebody down the       distribution 

       > chain. In any case, ill-conceived. Replacing the alternator       with a

       > belt-driven, automotive derivative is also a practical       option.

       > 

       > 

       > Bob . . .

     

     

      [quote][b]

nuckollsr

Joined: 24 Mar 2009
Posts: 95
Location: Medicine Lodge, KS

Posted: Sat Apr 25, 2015 2:40 pm Post subject: alternator

At 11:00 2015-04-25, you wrote:

  	  Quote: 	
		  Hello Bob,

 

 As astounding as it sounds, this mod indeed comes from the Jabiru factory themselves. Run a search for AVDALSR87 on Google and you will find the PDF listed as the first hit, direct from the Jabiru site. There is a second version (AVDALSR87-2) with a bit more explanation around, but nowhere does either version mention the loss of current delivery capability. It just touts the ability to charge the battery at near-idle speeds. Several people asked Jabiru about it and they claimed no loss of power from this mod. 	


   That's sad . . . but I guess not a great surprise.

   More and more companies have become so siloed and

   victim to the 'let's farm that out' syndrome that

   they loose command and control over critical aspects

   of their products.



 

  	  Quote: 	
		  Considering the same current draw from the plane's electric system and the internal losses (= heat) in the alternator coil quadrupling at equal current draw with this mod (going from 1/2R to 2R), it is no surprise the coil will burn up. 	


   Agreed. 



  	  Quote: 	
		  The belt driven alternative has two positive effects. First, there's more electrical power available, also at low idle speed. Second, the belt drive dampens torque pulses which helps keep the flywheel bolts intact. Definitely te way to go. 	


   Yeah . . . but that PM alternator is so damned simple,

   elegant and robust. With the right electronics, it COULD

   be a significant ingredient in the recipe for success.

   Rotax too . . .



   I'm working on that . . .



 

 

 Bob . . . 



 

 -----------------------------

 Bob Nuckolls

 AeroElectric Connection

 P.O. Box 130

 Medicine Lodge, KS  67104-0130

 Mobile: 316-209-7528

 Web:  http://aeroelectric.com

 ------------------------------    [quote][b]

nuckollsr

Joined: 24 Mar 2009
Posts: 95
Location: Medicine Lodge, KS

Posted: Sat Apr 25, 2015 2:42 pm Post subject: alternator

Can anyone on the list give me a measurement of

AC volts developed by the stock, parallel wound

3300 PM alternator at idle speed. Need to know what

that speed is too . . .



Bob . . .

-----------------------------

Bob Nuckolls

AeroElectric Connection

P.O. Box 130

Medicine Lodge, KS  67104-0130

Mobile: 316-209-7528

Web: http://aeroelectric.com

------------------------------

gilles.thesee(at)free.fr
Guest

Posted: Sun Apr 26, 2015 4:06 am Post subject: alternator

Le 25/04/2015 18:00, Rob Turk a Ã©crit :

 	  Quote: 	
		   Hello Bob,



 As astounding as it sounds, this mod indeed comes from the Jabiru 

 factory themselves. Run a search for AVDALSR87 on Google and you will 

 find the PDF listed as the first hit, direct from the Jabiru site. 

 There is a second version (AVDALSR87-2) with a bit more explanation 

 around, but nowhere does either version mention the loss of current 

 delivery capability.


	


Rob and all,



I'm afraid I could not find any of those documents through a Google 

search, and the Jabiru official website doesn't seem to list them.

Would it be possible to obtain a direct link to those pdf's ?



Thanks,

Best regards,



Gilles

http://contrails.free.fr

matronics(at)rtist.nl
Guest

Posted: Sun Apr 26, 2015 7:22 am Post subject: alternator

Hi Bob,

     

     I had the cowl off today so it was easy to measure. My engine runs     800rpm idle, which produces 7.2V AC. At 1000rpm I measured 9.0V AC.     Please not that these were measured with a DVM and the alternator     output is probably not a clean sine wave.

     

     I didn't dare to leave the cockpit at higher rpm, but at 1400rpm my     'low charge' light goes out. Assuming linear beaviour that would be     at 12.6V AC

     

     Hope this helps,

     Rob

     

     On 4/26/2015 12:42 AM, Robert L Nuckolls III wrote:

     > --> JabiruEngine-List       message posted by: Robert L Nuckolls III

       > <bob.nuckolls(at)aeroelectric.com> (bob.nuckolls(at)aeroelectric.com)

       > 

       > Can anyone on the list give me a measurement of AC volts       developed by

       > the stock, parallel wound 3300 PM alternator at idle speed.       Need to

       > know what that speed is too . . .

       > 

       > 

       > 

       > Bob . . .

       > 

     

      [quote][b]

europa471

Joined: 08 Apr 2009
Posts: 35

Posted: Sun Apr 26, 2015 4:20 pm Post subject: alternator

Gilles



Try this link: 

http://jabiru.net.au/images/AVDALSR087-2_12_Pole_Alternator_Mod.pdf



If that doesnÂ´t work, IÂ´ll post the .PDF.



Regards



Lance



On 26/04/15 22:05, GTH wrote:

 	  Quote: 	
		   



 Le 25/04/2015 18:00, Rob Turk a Ã©crit :

> Hello Bob,

>

> As astounding as it sounds, this mod indeed comes from the Jabiru 

> factory themselves. Run a search for AVDALSR87 on Google and you will 

> find the PDF listed as the first hit, direct from the Jabiru site. 

> There is a second version (AVDALSR87-2) with a bit more explanation 

> around, but nowhere does either version mention the loss of current 

> delivery capability.



 Rob and all,



 I'm afraid I could not find any of those documents through a Google 

 search, and the Jabiru official website doesn't seem to list them.

 Would it be possible to obtain a direct link to those pdf's ?



 Thanks,

 Best regards,



 Gilles

 http://contrails.free.fr

nuckollsr

Joined: 24 Mar 2009
Posts: 95
Location: Medicine Lodge, KS

Posted: Sun Apr 26, 2015 7:21 pm Post subject: alternator

At 19:19 2015-04-26, you wrote:

 	  Quote: 	
		  

Sandford <lsandford(at)westnet.com.au>



Gilles



Try this link: 

http://jabiru.net.au/images/AVDALSR087-2_12_Pole_Alternator_Mod.pdf



If that doesnÂ´t work, IÂ´ll post the .PDF.


	


   I was able to download using link above. I see

   a citation for 12v (at) 900 rpm and elsewhere

   a citation of 40V at 3000 rpm. These two

   values are consistent with each other.



   This says that the paralleled winding produces

   about 20VAC at 3000 rpm . . . this was the

   value I was looking for.



   Thanks!





Bob . . .

-----------------------------

Bob Nuckolls

AeroElectric Connection

P.O. Box 130

Medicine Lodge, KS  67104-0130

Mobile: 316-209-7528

Web: http://aeroelectric.com

------------------------------

gilles.thesee(at)free.fr
Guest

Posted: Mon Apr 27, 2015 1:43 am Post subject: alternator

Le 27/04/2015 02:19, Lance Sandford a Ã©crit :

 	  Quote: 	
		   

 <lsandford(at)westnet.com.au>



 Gilles



 Try this link: 

 http://jabiru.net.au/images/AVDALSR087-2_12_Pole_Alternator_Mod.pdf




	


Lance and all,



Thank you for the link, and thank you for those who reponded privately.

It's great to get help so quickly.

Ironically, now Google works as expected and yields lots of responses^^!



Thanks again,

Best regards,

Gilles



http://contrails.free.fr

BobbyPaulk(at)comcast.net
Guest

Posted: Mon Apr 27, 2015 12:40 pm Post subject: Alternator

List 



I was getting 14.6 volts steady at 1200 and 1400 rpm while taxiing out. My amp meter hunts so I do not know what it was putting out ( Zero to 4 indicated ). After the first flight that had Icom radio, Dynon Efis, and the Ro-tec E mag I figured about five to seven amps with the radio not transmitting. The volt meter was still steady at 14.6. 



One thing I did observe was when I put the battery tender on it it only took about 10 minutes or less for the green light to come on. It usually takes 25 to 30 minutes. 



I believe the coils shorted out when I added load by turning on the strobes. After I removed the coils it looks like the varnish could have been rubbed off at the corner of the turn where the wires exit to the backside of the coils. I could not really tell since the wire was blackened and had no varnish left.  



One circuit was burned black ( all 6 coils ) while the other circuit was in tact. 

I knew it was a trade off by going to one series circuit in lieu of the 2 parallel but I was used to turning off the transponder on short final and the strobes after exiting the runway ( unless there was ground traffic).



Anyway I am afixin to order the CAMit 40 ~ 45 amp alternator and adapter kit. That ought to fix the problem unless I have another self induced uh-oh!



Thanks to all that responded ( no flames : )



bobby

 [quote][b]

nuckollsr

Joined: 24 Mar 2009
Posts: 95
Location: Medicine Lodge, KS

Posted: Mon Apr 27, 2015 2:23 pm Post subject: Alternator

At 15:39 2015-04-27, you wrote:

 	  Quote: 	
		  List

I was getting 14.6 volts steady at 1200 and 1400 rpm while taxiing 

out. My amp meter hunts so I do not know what it was putting out ( 

Zero to 4 indicated ). After the first flight that had Icom radio, 

Dynon Efis, and the Ro-tec E mag I figured about five to seven amps 

with the radio not transmitting. The volt meter was still steady at 14.6.

One thing I did observe was when I put the battery tender on it it 

only took about 10 minutes or less for the green light to come on. 

It usually takes 25 to 30 minutes.

I believe the coils shorted out when I added load by turning on the 

strobes. After I removed the coils it looks like the varnish could 

have been rubbed off at the corner of the turn where the wires exit 

to the backside of the coils. I could not really tell since the wire 

was blackened and had no varnish left.

One circuit was burned black ( all 6 coils ) while the other circuit 

was in tact.

I knew it was a trade off by going to one series circuit in lieu of 

the 2 parallel but I was used to turning off the transponder on 

short final and the strobes after exiting the runway ( unless there 

was ground traffic).

Anyway I am afixin to order the CAMit 40 ~ 45 amp alternator and 

adapter kit. That ought to fix the problem unless I have another 

self induced uh-oh!



Thanks to all that responded ( no flames : )



bobby


	




Sadly, your observations on the series-connected

alternator 'experiment' were somewhat predictable.

Sorry you've had to suffer the indignities imposed

by the laws of physics.



The PM alternator has been poorly exploited for the

best it has to offer. PM alternators are simple, long

lived, robust and not terribly inefficient. Unfortunately,

the rectifier/regulator combinations have NOT evolved

with the best that power electronics has to offer.



We're doing the rudimentary proof of concept studies

for a PM alternator R/R that will offer greater

maximum output commensurate with the alternator's

real ability to convert mechanical motion into

electrical energy.



The belt driven alternator is a low-risk albeit

heavier and more expensive alternative. It may indeed

be the most practical solution depending on you

use your airplane.



But it's possible that a modern R/R configuration will

breath new life into the PM alternator concept with

increased performance and system reliability.



We shall see .. .





Bob . . .

-----------------------------

Bob Nuckolls

AeroElectric Connection

P.O. Box 130

Medicine Lodge, KS  67104-0130

Mobile: 316-209-7528

Web: http://aeroelectric.com

------------------------------

BARRY CHECK 6

Joined: 15 Mar 2011
Posts: 738

Posted: Tue Apr 28, 2015 7:38 am Post subject: Alternator

Right you are Bob N.!

Things will NOT change until many more 'builders'...  Not Engineers, come to the realization that: You can't fool Mother Physics!  Physics is what it is and no matter how much hoping and praying you do, you CAN'T change it!  

When this issue first came up years ago I posted something like:  You can't get blood from a stone and why not just install a small AUTOMOTIVE alternator with built in ACU!  All sorts of responses surfaced...  I don't want to loose the extra HP the alternator will require.  Too much weight.  What do I do with the built in unit...  DUH!  Remove it! The only acceptable response was: I don't have room to install it - No room under the cowl.  Now, here I have feeling for the poor builder.  

Small alternators such as the MITSUBISHI are as small a large man's hand and put out 40 to 70 Amps.  Simple, easy to install, easy to diagnose, easy to regulate (built in), easy to replace if you breakdown at a remote airport...  Just SIMPLY EASY!  So, why kill yourself trying to get blood from a stone?  And I like Jabiru Engines...  I hate Rat-Tax (Rotex).

Barry

On Mon, Apr 27, 2015 at 6:21 PM, Robert L Nuckolls III <bob.nuckolls(at)aeroelectric.com (bob.nuckolls(at)aeroelectric.com)> wrote:

[quote]--> JabiruEngine-List message posted by: Robert L Nuckolls III <bob.nuckolls(at)aeroelectric.com (bob.nuckolls(at)aeroelectric.com)>

 

 At 15:39 2015-04-27, you wrote:

  	  Quote: 	
		   List

 I was getting 14.6 volts steady at 1200 and 1400 rpm while taxiing out. My amp meter hunts so I do not know what it was putting out ( Zero to 4 indicated ). After the first flight that had Icom radio, Dynon Efis, and the Ro-tec E mag I figured about five to seven amps with the radio not transmitting. The volt meter was still steady at 14.6.

 One thing I did observe was when I put the battery tender on it it only took about 10 minutes or less for the green light to come on. It usually takes 25 to 30 minutes.

 I believe the coils shorted out when I added load by turning on the strobes. After I removed the coils it looks like the varnish could have been rubbed off at the corner of the turn where the wires exit to the backside of the coils. I could not really tell since the wire was blackened and had no varnish left.

 One circuit was burned black ( all 6 coils ) while the other circuit was in tact.

 I knew it was a trade off by going to one series circuit in lieu of the 2 parallel but I was used to turning off the transponder on short final and the strobes after exiting the runway ( unless there was ground traffic).

 Anyway I am afixin to order the CAMit 40 ~ 45 amp alternator and adapter kit. That ought to fix the problem unless I have another self induced uh-oh!

 

 Thanks to all that responded ( no flames : )

 

 bobby

 	
 

 

 Sadly, your observations on the series-connected

 alternator 'experiment' were somewhat predictable.

 Sorry you've had to suffer the indignities imposed

 by the laws of physics.

 

 The PM alternator has been poorly exploited for the

 best it has to offer. PM alternators are simple, long

 lived, robust and not terribly inefficient. Unfortunately,

 the rectifier/regulator combinations have NOT evolved

 with the best that power electronics has to offer.

 

 We're doing the rudimentary proof of concept studies

 for a PM alternator R/R that will offer greater

 maximum output commensurate with the alternator's

 real ability to convert mechanical motion into

 electrical energy.

 

 The belt driven alternator is a low-risk albeit

 heavier and more expensive alternative. It may indeed

 be the most practical solution depending on you

 use your airplane.

 

 But it's possible that a modern R/R configuration will

 breath new life into the PM alternator concept with

 increased performance and system reliability.

 

 We shall see .. .

 

 

 

 

 Bob . . .

 

 

 -----------------------------

 Bob Nuckolls

 AeroElectric Connection

 P.O. Box 130

 Medicine Lodge, KS  67104-0130

 Mobile: [url=tel:316-209-7528]316-209-7528[/url]

 Web: http://aeroelectric.com

 ------------------------------ 

 

 ===========

 ne-List" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-List

 ===========

 ">http://forums.matronics.com

 ===========

 le, List Admin.

 ="_blank">http://www.matronics.com/contribution

 ===========

 

 

 

 



[b]

nuckollsr

Joined: 24 Mar 2009
Posts: 95
Location: Medicine Lodge, KS

Posted: Tue Apr 28, 2015 8:24 am Post subject: Alternator

At 10:37 2015-04-28, you wrote:

 	  Quote: 	
		  Right you are Bob N.!



Things will NOT change until many more 'builders'...  Not Engineers, 

come to the realization that: You can't fool Mother 

Physics!  Physics is what it is and no matter how much hoping and 

praying you do, you CAN'T change it!



When this issue first came up years ago I posted something 

like:  You can't get blood from a stone and why not just install a 

small AUTOMOTIVE alternator with built in ACU!  All sorts of 

responses surfaced...


	


     To be sure, the universe runs on physics and

     no matter what discipline one plies their

     talents, it all comes down to properties of

     materials and management of energy.



     The evolution of the PM alternator has roots

     on small bikes and RV's like snow-mobiles. They

     often mounted a "lighting coil" on the crankcase

     and spun a magnet close by to offer perhaps 20-30

     watts of AC to light a headlamp.



     The ghost of F. Kettering must have been smiling

     down on the endeavor as individuals began to

     ponder ways that the headlamp intensity could

     be maintained over full range of engine rpm . . .

     not limited to full bright at open throttle.



     So the simple rectifier/regulator came along

     with a crude voltage control profile that

     prevented serious overcharging of the battery.

     Keep in mind that ALL this was before rare

     earth and SLVA technologies.



     Yeah . . . it kinda worked okay. The regulators

     were simple silicon controlled rectifiers that

     were 'fired' as a dead short across the alternator

     when the bus voltage got too high. Hence, the

     alternator was fully loaded all the time. Furhter

     it had to be inherently current limiting to keep

     it from smoking when there were no system loads

     and the battery was fully charged.



     Then came rare earth magnets. About the same

     time, SLVA batteries pushed their flooded

     ancestors into a timely and well deserved

     place in history. A new breed of R/R came along

     which formed a bridge rectifier with SCR's in

     two legs of the bridge for control by some

     rudimentary electronics.



     Again, not the best we knew how to do but

     ADEQUATE to contemporary design goals. Examples

     example of this now dated technology include

     the successes logged by Rotax, B&C (The SD-8

     was B&C's first product. I was a collaborator

     on that development and helped them purchase

     the sand-castings for Electro-Mech standby

     generators for Bonanza's AND20000 pad

     drive pad).



     The improved alternators benefited from rare

     earth,  So while AVAILABLE AC power from

     the alternator went up . . . DC power demands

     on the airplanes being built went up too.

     Sadly, the R/R did not evolve with the power

     electronics side of the house.



     There has never been anything inherently EVIL

     or even grossly7 inept about the participants

     in this saga. Each feature from alternator

     to R/R, to battery, to evolution of the

     all-electric OBAM aircraft was plotting along

     with each technology driven by separate

     marketing and business models most of which

     hand nothing to do with the unique electrical

     environment that was evolving on OBAM aircraft.



     As a 45+ year observer and participant in art

     and science of systems design and fabrication,

     I can offer historical narrative above and

     propose the next big step in the evolution

     of the PM alternator as a practical, engine

     driven power source.



     The efficiency of the legacy triggered-bridge

     rectifier is terrible. I judge that these

     designs not only cripple the system's ability

     to deliver at low rpm and may toss off 20

     to 50% of total available energy as heat.



     The next step borrows from the energy management

     technologies ubiquitous in computers for decades.

     In the mean time, I would be cautious about

     bad-mouthing the PM alternator. Shortcomings

     in performance had little to do with design

     of the alternator and MUCH to do with design

     of the R/R.



     Did some development testing at B&C last week.

     Will probably be back there again this week.

     The ingredients that go into this recipe for

     success have existed for decades . . . it's

     a matter of picking the right combination . . .

     for properties of materials and management of

     energy.



Bob . . .

-----------------------------

Bob Nuckolls

AeroElectric Connection

P.O. Box 130

Medicine Lodge, KS  67104-0130

Mobile: 316-209-7528

Web: http://aeroelectric.com

------------------------------

matronics(at)rtist.nl
Guest

Posted: Tue Apr 28, 2015 8:55 am Post subject: Alternator

You said it, Bob. Modern technology switching regulators allow for wide 

input and constant output with high reliability, high efficiency and low 

weight.



On a Jabiru, a switching regulator must be designed to work with ~5:1 

input range (minimum 7 volt AC (at) 700rpm, maximum 35V(at)3300rpm.). The 

original windings are designed to deliver 20A, so at cruise of 2700rpm 

(~28V) it should deliver close to 500W of electrical power. If you'd use 

an efficient switcher you can get ~85-90% available, which translates to 

almost 30A(at)14.6V. Plenty for all but a flying Christmas tree. Oh, and a 

switching regulator would make it possible to go to a 28V system as 

well, saving weight on wiring.



Only concern I'd have with these is RF interference, these switchers 

aren't particularly clean..



Rob

On 4/28/2015 6:23 PM, Robert L Nuckolls III wrote:

 	  Quote: 	
		   

 <bob.nuckolls(at)aeroelectric.com>



 ...

     The next step borrows from the energy management

     technologies ubiquitous in computers for decades.

     In the mean time, I would be cautious about

     bad-mouthing the PM alternator. Shortcomings

     in performance had little to do with design

     of the alternator and MUCH to do with design

     of the R/R.



     Did some development testing at B&C last week.

     Will probably be back there again this week.

     The ingredients that go into this recipe for

     success have existed for decades . . . it's

     a matter of picking the right combination . . .

     for properties of materials and management of

     energy.



 Bob . . .

 -----------------------------

 Bob Nuckolls

 AeroElectric Connection

 P.O. Box 130

 Medicine Lodge, KS  67104-0130

 Mobile: 316-209-7528

 Web: http://aeroelectric.com

 ------------------------------

nuckollsr

Joined: 24 Mar 2009
Posts: 95
Location: Medicine Lodge, KS

Posted: Tue Apr 28, 2015 10:13 am Post subject: Alternator

At 11:54 2015-04-28, you wrote:

 	  Quote: 	
		  



You said it, Bob. Modern technology switching regulators allow for 

wide input and constant output with high reliability, high 

efficiency and low weight.



On a Jabiru, a switching regulator must be designed to work with 

~5:1 input range (minimum 7 volt AC (at) 700rpm, maximum 35V(at)3300rpm.


	


    The 5:1 range target assumes that the alternator's

    maximum rated ENERGY output is uniform over the

    range of RPM . . . which it is not.



 	  Quote: 	
		  . The original windings are designed to deliver 20A, so at cruise of 

2700rpm (~28V) it should deliver close to 500W of electrical power.


	


    What gage wire is used to wind those stators?



 	  Quote: 	
		    If you'd use an efficient switcher you can get ~85-90% available, 

 which translates to almost 30A(at)14.6V. Plenty for all but a flying 

 Christmas tree. Oh, and a switching regulator would make it 

 possible to go to a 28V system as well, saving weight on wiring.


	


   Based on the present state of development studies,

   I would expect a pretty good boost at cruise RPM

   perhaps as much as 50% over present capabilities.

   I would also expect USEFUL output to MUCH lower

   rpm levels than with the current technology. But

   hundreds of watts at idle is not in the cards

   without some re-design of the alternators. That

   would be the next phase of system upgrades.



 	  Quote: 	
		  Only concern I'd have with these is RF interference, these switchers 

aren't particularly clean..


	


   Switchmode regulators are widely used in a host

   of RFI sensitive environments. There is NO design

   that cannot be tailored to the most critical of

   EMC environments.



   I have desktop, consumer grade computer power supplies

   sitting right next to amateur radio equipment capable

   of sniffing microvolt level signals. I'm not suggesting

   that there aren't occasional 'birdies' but I've yet

   to be plagued by any of them. Got a nice HF transceiver

   I'll be putting into service as soon as I can get a new

   antenna up . . . I'll see if I need to modify those words.



   In any case, there's a LOT of computers co-existing in

   ham radio shacks . . . it can be done.



Bob . . .

-----------------------------

Bob Nuckolls

AeroElectric Connection

P.O. Box 130

Medicine Lodge, KS  67104-0130

Mobile: 316-209-7528

Web: http://aeroelectric.com

------------------------------

BobbyPaulk(at)comcast.net
Guest

Posted: Wed Apr 29, 2015 4:46 am Post subject: Alternator

Guys



Sometimes I know the outcome before I start but I have been known to beat a dead horse.



Just ask my kids.



The engine was on a stand, the flywheel off, and the coil / stator was begging me to change it : )



bobby

 [quote][b]

nuckollsr

Joined: 24 Mar 2009
Posts: 95
Location: Medicine Lodge, KS

Posted: Wed Apr 29, 2015 6:22 am Post subject: Alternator

At 07:45 2015-04-29, you wrote:

 	  Quote: 	
		  Guys

Sometimes I know the outcome before I start but I have been known to 

beat a dead horse.

Just ask my kids.

The engine was on a stand, the flywheel off, and the coil / stator 

was begging me to change it : )



bobby


	


  Do you have a 'carcass' stator I could have?





Bob . . .

-----------------------------

Bob Nuckolls

AeroElectric Connection

P.O. Box 130

Medicine Lodge, KS  67104-0130

Mobile: 316-209-7528

Web: http://aeroelectric.com

------------------------------

BobbyPaulk(at)comcast.net
Guest

Posted: Thu Apr 30, 2015 4:35 am Post subject: Alternator

Bob,



You are welcome to the stator "carcass".



Send me an e-mail off list whether to send to the P.O. Box or a street address. 



Hope you find something of interest. 



Question: Has anyone installed the CAMit Alternator on a Jabiru 3300 mounted on a Zodiac 601.



I would like to verify it clears the upper left engine mount. I believe it does but would like to double check before ordering. 



Bobby

 [quote][b]

Display posts from previous:

	Matronics Email Lists Forum Index -> JabiruEngine-List	All times are GMT - 8 Hours Goto page 1, 2 Next
Page 1 of 2

Jump to:

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum