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mark.bitterlich(at)navy.m
Guest

Posted: Wed Feb 20, 2008 2:56 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

The subject was written to warn the people that get bored from reading

"Mark and Brian" discussions.  Now you can't say you were not warned!  



If you went this far, .. Be advised that this is a discussion on

Alternators and Generators.  More of the same.  Interesting to few but

the very dedicated electronic types.  

Ok Brian... I'm going to take some pot shots here, and the YAK readers

will take it in the shorts from boredom I am sure!       



Double >>'s from me. 

Single >'s from Brian. 

No >'s, this reply. 

 	  Quote: 	
		  > P.s.  Another little tidbit between Alternators and Generators.

>

> 1.  If your batteries ever go totally dead in the air or on the 

> ground... I mean zero or really LOW battery voltage.... And the 

> alternator is not already on-line... It will never turn on.


	


 	  Quote: 	
		  Not entirely true. Self-exciting alternators will. 

Even a regular alternator will come on line if you can get all the 

loads off the bus first.


	


True.   Now name a light civil aircraft with a self-exciting alternator

installed.  The small B&C PMG "Alternator" will in fact do that.  It

also has no field input winding as you know. It uses permanent magnets.

Yes, the "Alternators" on the EA-6B Prowler have a PMG winding as well

that is then used to excite the main field.  These are indeed

self-exciting and it is agreed that such models exist.  These are 3

phase 30 KVA models by the way.  And yes, I have 38 years experience

working with self exciting alternators, (HANDS ON Brian) but I have yet

to see one on a Cessna.  If the readers of this list want to discuss the

power generating systems on a 747, then heck yes!  However, sorry... not

on the YAK LIST and not on the Chevy in your garage either.  



As far as a "regular" alternator coming on line with all loads

removed..... I'd like to see it done please.  I went out to my 68 Camaro

and tried it.  It did not work.  I went out to a Cessna 180 (1974 model)

and it did not work. Then a 182, then a Piper 140, then a YAK-52TW. No

cheese.  I suspect that what you are suggesting is connecting a wire

jumper directly from the output to the field.  Impossible to do

in-flight, and not a bright thing to do on the ground. If I am wrong

here, please correct me.  Never-the-less, I tried exactly that and it

failed to work.  



So yes, again with respect, your point in theory is entirely valid.

However, I do not consider it to be Germaine unless you can point to

exactly which make and model of aircraft, or even automobile that you

actually made it work on.  



 	  Quote: 	
		  > It needs a little juice to get it going so to speak.


	


 	  Quote: 	
		  That is true. OTOH the reason that the generator comes on-line without

the battery is the residual 
	


 	  Quote: 	
		  magnetism in the field. 


	


I concur, and a generator does not come from the factory that way.  It

has to be "FLASHED" in order to start working the very first time.

Agreed, some manufactures' did that for you back in the day.  Depending

on how long it "sat" it sometimes still needed it upon installation.   



 	  Quote: 	
		  The alternator has the same thing. 


	


Define what you mean by the "same thing".  An alternator NEVER needs to

be "flashed" coming out of the box.  It does NOT rely on self-induced

magnetism, and it is not a design FEATURE.... Except.... On very special

models usually found on commercial or military aircraft designed for the

express purpose of running WITHOUT any kind of battery at all.  



 	  Quote: 	
		  You can see this by disconnecting the 'B' lead, putting a voltmeter on

it, and spinning up the alternator. 
	


 	  Quote: 	
		  You will get some output. It should be enough to excite the field to

bootstrap the alternator to full 
	


 	  Quote: 	
		  output as long as nothing else is using that output. As I said, that is

how a self-exciting alternator 
	


 	  Quote: 	
		  gets going.  And most internally-regulated alternators are self

exciting.
	




Interesting theory.  How much does that meter load the output do you

think? Yes, I am sure you can get some voltage on a meter.  In my recent

experience, not enough current to get the field excited though.   It did

not work on any test I ran.  As you pointed out, there are a lot of "1

wire" alternators out there.  I have one on my 68 Camaro... A 100 amp

alternator.  It does NOT self-excite.  Period.    



 	  Quote: 	
		  But there is another issue. Neither a generator system nor an

alternator system should 
	


 	  Quote: 	
		  be operated without a battery in the circuit.  


	


I assume we have now jumped back to common general aviation aircraft,

because only a very few modern tactical military aircraft have ANY kind

of battery even installed! Granted some do have APU's.  However, take

the whole A-6 product line for example.  No battery except for

activating a spin assist circuit, and their alternators run the whole

aircraft without a problem....no batteries needed.   



This is an example of "reverse nit-picking" and I admit it.  Point is,

some systems were designed to be operated with a battery and some

without.  Some alternators can self excite, most can not. Discussions

then need to stay targeted on one thing at a time.  



ANYWAY....Yes, I agree.... On models designed to run with a battery it

is true that it is inadvisable to run the system without one. Unless

maybe your life is at stake.  Say, IFR at night.  Or, as a young Marine

trying to get back to the base after his battery had been stolen out of

his car and no money to buy a new one, and too honest to swipe someone

else's.  A 12 volt lantern battery WILL excite a car alternator enough

to get it going.  Been there, done that, have the tea-shirt. Drove 500

miles back to the base exactly that way.  



 	  Quote: 	
		  The battery is needed to stabilize the voltage. Without it you have

nothing to absorb the 
	


 	  Quote: 	
		  excess output when you load-dump. Neither an alternator nor a generator

can change its 
	


 	  Quote: 	
		  output suddenly. It takes time for the magnetism in the field to ramp

up or ramp down 
	


 	  Quote: 	
		  with a field current change. (Current lags voltage in an inductor if

you want to get technical.) 
	




Yes... I am familiar with AC theory Brian... And yes I remember ELI the

ICE man. But... You kind of make it sound like without the battery,

everything will self-destruct.  



 	  Quote: 	
		  That means that, without a battery, turn off the landing light and

watch the alternator or 
	


 	  Quote: 	
		  generator create an over voltage event.


	


Better yet, leave it on and watch it tend to smooth out voltage

excursions.  



That said, I went out to my YAK-50 last night and disconnected the

battery.  I then started it.  I then ran up the engine to about 50 % and

called the tower and flew it around the pattern with no battery

connected.  Nothing burnt out.  Everything worked fine. It was not much

of a risk really.  On a flight a few years ago I blew the battery fuse

in flight. Well... Actually the fuse holder fell apart... But same

thing.  I never even knew it until I idled the engine down and

everything in the cockpit went dead.  



This morning I went out to my old piece of junk Renault Alliance.  I

started the car.  I then rev'ed the engine up to 2000 RPM and

disconnected the battery.  It took two people to pull this stunt off.  I

then drove it around the block.  Nothing bad happened.  Of course I did

not have a $10,000 Avionics Stack fired up either.  



 	  Quote: 	
		  Now we have said WAY more about alternators and generators than anyone

else wanted to hear. 
	




Probably so.  



Mark Bitterlich



P.s.  Here is my opinion, and I have tried it.  If you are flying around

and suspect you have a bad battery, DO NOT TURN OFF THE ALTERNATOR to

check your battery voltage, it very well might not come back on with

zero, or even near zero battery voltage.  It is also entirely possible

that the aircraft will be subject to inductive voltage kicks from

operating that alternator without a battery (as Brian pointed out).

These might even be high enough to cause equipment damage under the

right conditions.  As the pilot in command, you'll have to make the

decision which possibility is worse for you.  However, my testing

confirms that if you turn off the alternator with a dead battery,

turning it back on will accomplish nothing unless you are lucky enough

to have just a little something left in the battery to excite the

alternator allowing it to get back on line.  



Next, regardless of alternator OR generator, if either is on-line and

you have a bad battery, the power you DO generate will power the landing

gear motor, will run all your lights, and HOPEFULLY will not damage your

avionics.   Given the tests I just ran in my aircraft, I would not

hesitate to do it.  And yes, the tower reported bad hum in my

transmissions.  However my little Apollo 360 GPS hung in there without a

hick-up. 



P.p.s.  And Brian, I am not saying you are WRONG in any way.  I am

saying that it is easy to switch back and forth between discussing

apples and oranges during any kind of electronic discourse of this

nature.  Apples remain apples and oranges remain orange.  However, when

you put them in the same bowl, we need to be careful not to act like

they are the same fruit.  My 2 cents anyway.

wlannon(at)persona.ca
Guest

Posted: Wed Feb 20, 2008 7:50 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

Well, I for one do not get bored reading "Mark and Brian" discussions. You 

both know much more than I do on this subject and I have been restoring and 

maintaining Warbird types for at least 40 years.

Probably because I'm too old to know any better I have nothing but positive 

things to say about the Bendix Eclipse generator, carbon pile regulator and 

control units used in these aircraft.

There are questions I would like to put to you but since these are specific 

to the above systems I would bore everyone else so will pass.

Keep up the good work.



Cheers;

Walt



---

brian-1927(at)lloyd.com
Guest

Posted: Wed Feb 20, 2008 9:14 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

 	  Quote: 	
		  > Not entirely true. Self-exciting alternators will.

> Even a regular alternator will come on line if you can get all the

> loads off the bus first.



 True.   Now name a light civil aircraft with a self-exciting  

 alternator

 installed.


	


Well, my CJ "Betty" did. Still does I am pretty sure. It is why you  

have to get the RPM up to about 2000 before the alternator comes on- 

line. After that it is fine even at idle until you shut it down.



 	  Quote: 	
		   As far as a "regular" alternator coming on line with all loads

 removed..... I'd like to see it done please.


	


If you have an internally-regulated alternator with the internal VR  

powered from a diode trio from the stator, your alternator will self- 

excite. Every IR alternator so wired I have tried did self-excite. I  

have done this with GM Delco, Ford Autolite, and Motorola.



 	  Quote: 	
		   I went out to my 68 Camaro

 and tried it.  It did not work.  I went out to a Cessna 180 (1974  

 model)

 and it did not work. Then a 182, then a Piper 140, then a YAK-52TW. No

 cheese.  I suspect that what you are suggesting is connecting a wire

 jumper directly from the output to the field.


	


No.



 	  Quote: 	
		   I concur, and a generator does not come from the factory that way.  It

 has to be "FLASHED" in order to start working the very first time.

 Agreed, some manufactures' did that for you back in the day.   

 Depending

 on how long it "sat" it sometimes still needed it upon installation.


	


Yes.



 	  Quote: 	
		  > The alternator has the same thing.



 Define what you mean by the "same thing".  An alternator NEVER needs  

 to

 be "flashed" coming out of the box.  It does NOT rely on self-induced

 magnetism, and it is not a design FEATURE.... Except.... On very  

 special

 models usually found on commercial or military aircraft designed for  

 the

 express purpose of running WITHOUT any kind of battery at all.


	


As with all steel armature pole pieces, if you apply a magnetic field  

for a long period of time it will become at least partially magnetized  

permanently. The residual magnetism in the armature will induce  

voltage in the stator. That voltage may be (probably is) less than  

battery voltage so you would never see enough output to charge the  

battery. But it is enough to turn on the internal VR which will then  

shunt the small available current into the field. This will increase  

the output which then increases the current in the field. This  

positive feedback process continues until the unit is fully on-line.



So I find your negative results very surprising. Every internally- 

regulated alternator I have used that is self-powered through the  

diode trio connected to the stator (independent of the normal diode  

bridge that feeds output to the B lead) has been self-exciting in the  

manner I have described.



 	  Quote: 	
		  > gets going.  And most internally-regulated alternators are self

 exciting.



 Interesting theory.


	


'Taint theory.



 	  Quote: 	
		   How much does that meter load the output do you

 think?


	


Nothing to speak of. If you you are looking at the B-lead you are  

getting two diode drops, not 1. That makes things worse. The diode  

trio works with a single diode drop hence you have almost an extra  

volt available from the feeble output of the stator from the residual  

magnetism in the rotor.



 	  Quote: 	
		   Yes, I am sure you can get some voltage on a meter.  In my recent

 experience, not enough current to get the field excited though.


	


Tap the diode trio.



 	  Quote: 	
		   It did

 not work on any test I ran.  As you pointed out, there are a lot of "1

 wire" alternators out there.  I have one on my 68 Camaro... A 100 amp

 alternator.  It does NOT self-excite.  Period.


	


I am surprised. You have just told me about the first one that did not  

self-excite that I have heard of. Remember, a "1-wire" alternator has  

to self excite or it must get some power from the battery. Actually  

most alternators get a tiny current from teh battery through the idiot- 

light circuit. The 100mA or so needed to light that lamp is more than  

enough to turn on the internal VR and the field even at idle. But if  

you disconnect the idiot light circuit the alternator has to self- 

excite. It will.



 	  Quote: 	
		  > But there is another issue. Neither a generator system nor an

 alternator system should

> be operated without a battery in the circuit.



 I assume we have now jumped back to common general aviation aircraft,

 because only a very few modern tactical military aircraft have ANY  

 kind

 of battery even installed!


	


Yes, I am talking about GA aircraft. Hell, I am talking about most  

aircraft. And no, I am not talking about current military aircraft  

with electrical systems designed not to need a battery. This whole  

discussion started with alternators and generators on Yak/CJ aircraft  

and that is where I thought we were. It is certainly possible to  

construct an alternator controller and output clamping system that  

will prevent a load-dump incident but the standard alternator (or  

generator) that is used in a run-of-the-mill automobile or GA aircraft  

doesn't have that.



 	  Quote: 	
		   Granted some do have APU's.  However, take

 the whole A-6 product line for example.  No battery except for

 activating a spin assist circuit, and their alternators run the whole

 aircraft without a problem....no batteries needed.



 This is an example of "reverse nit-picking" and I admit it.


	


Keine sheiss, meine Herr. I was talking about electrical systems in  

the aircraft we own, not necessarily the ones some of us are paid to  

fly into harm's way.



 	  Quote: 	
		   Point is,

 some systems were designed to be operated with a battery and some

 without.  Some alternators can self excite, most can not. Discussions

 then need to stay targeted on one thing at a time.



 ANYWAY....Yes, I agree.... On models designed to run with a battery it

 is true that it is inadvisable to run the system without one. Unless

 maybe your life is at stake.  Say, IFR at night.  Or, as a young  

 Marine

 trying to get back to the base after his battery had been stolen out  

 of

 his car and no money to buy a new one, and too honest to swipe someone

 else's.  A 12 volt lantern battery WILL excite a car alternator enough

 to get it going.  Been there, done that, have the tea-shirt. Drove 500

 miles back to the base exactly that way.


	


Sure, you can do it. If your loads remain relatively constant  

everything will work out fine without a battery. Even a honkin' big  

capacitor will do the trick. But if you take the battery out of the  

circuit, leave the alternator on, bring up the load with lights, pitot  

heat, butt-warmer, etc., and then turn off some large load, the output  

of the alternator will go a lot higher than you want for a short  

period of time. This is called a load-dump incident and you need  

something to absorb the extra output.



But even some spam-can electrical systems can run without a battery. I  

believe some of the Beechcraft are designed to run from their  

alternators without the battery on-line. It all depends on how you  

design the system.



But as a rule of thumb, running your electrical system in your car or  

GA aircraft (or CJ or Yak) without the battery on-line, you are asking  

for problems. Maybe not this time or the next but if you keep doing  

it, it will bite you in the butt some day.



 	  Quote: 	
		  



> The battery is needed to stabilize the voltage. Without it you have

 nothing to absorb the

> excess output when you load-dump. Neither an alternator nor a  

> generator

 can change its

> output suddenly. It takes time for the magnetism in the field to ramp

 up or ramp down

> with a field current change. (Current lags voltage in an inductor if

 you want to get technical.)



 Yes... I am familiar with AC theory Brian... And yes I remember ELI  

 the

 ICE man. But... You kind of make it sound like without the battery,

 everything will self-destruct.


	


No, I am saying that without the battery to provide a load for the  

momentary overvoltage situation caused by load-dump, you will get a  

big spike, the energy content of which is a function of the inductance  

of the field.



Most solid-state regulators for alternators and generators use a  

series pass transistor which switches on and off to pulse-width  

modulate the field current. (I will be happy to draw you a schematic  

but you can imagine a comparitor driving the base of the switch  

transistor, turning the transistor on when the voltage is below the  

setpoint and off when it is above.) The problem is that when the  

transistor switches off, the back EMF from the field is high enough to  

damage the switch transistor. So they put in a clamp diode to protect  

the transistor. The problem here is that the clamp diode allows the  

back EMF a low-impedance path to ground keeping current flowing in the  

field. This slows down the collapse of the field. This tends to hold  

the output of the alternator high for some number of milliseconds  

longer than you expect.



So imagine the situation now. You have a lot of loads on. The  

alternator is working its little butt off. The field current is pretty  

high. Suddenly you turn off the load. The bus voltage starts to rise.  

The VR shuts off the field but the collapsing B-field from the  

armature induces a big back-EMF. The clamp diode shunts the current  

from the back-EMF to ground which holds up the B-field. The output of  

the alternator continues to rise even tho' the VR has done the right  

thing and it is no longer sourcing field current. This goes on until  

the B-field collapses. This may take 10's or 100's of milliseconds. At  

that point the output of the alternator drops. If the battery is  

there, it absorbs the extra energy and the voltage on the bus moves  

only a little. If there is no device to absorb that extra energy, e.g.  

battery, capacitor, transorb, clamping zener, dedicated clamp circuit,  

etc., you will see a big spike. If there is enough energy in that  

spike it can damage the power supplies in your avionics.



Load dump is real.



 	  Quote: 	
		  > That means that, without a battery, turn off the landing light and

 watch the alternator or

> generator create an over voltage event.



 Better yet, leave it on and watch it tend to smooth out voltage

 excursions.  



 That said, I went out to my YAK-50 last night and disconnected the

 battery.  I then started it.  I then ran up the engine to about 50 %  

 and

 called the tower and flew it around the pattern with no battery

 connected.  Nothing burnt out.  Everything worked fine.


	


Doesn't your Yak-50 use a B&C PM alternator? They work differently and  

they will not exhibit load-dump effect. You need an alternator or  

generator with a field circuit. Also, the larger the alternator, the  

more profound the effect. You might see load-dump effect with a small  

field-circuit alternator but you will find that the energy in the  

spike is not enough to be a problem.



Hell, I would expect a PM alternator (dynamo) to run just fine without  

a battery.



But lets say you are still running the stock generator. I would not  

expect a load-dump event in your Yak-50. You aren't switching big  

loads off. You don't have anything like a landing-gear motor. Repeat  

your experiment, this time with the landing light and pitot-heat on.  

Turn them both off at the same time. I betcha you get a GOOD spike.

 	  Quote: 	
		   It was not much

 of a risk really.  On a flight a few years ago I blew the battery fuse

 in flight. Well... Actually the fuse holder fell apart... But same

 thing.  I never even knew it until I idled the engine down and

 everything in the cockpit went dead.



 This morning I went out to my old piece of junk Renault Alliance.  I

 started the car.  I then rev'ed the engine up to 2000 RPM and

 disconnected the battery.  It took two people to pull this stunt  

 off.  I

 then drove it around the block.  Nothing bad happened.  Of course I  

 did

 not have a $10,000 Avionics Stack fired up either.


	


And you probably did not create a load-dump. That is where the problem  

arises. Do that again and remove a big load, e.g. turn off the  

headlights. Put a 'scope on the bus. It will make a believer out of you.



Mark, I like you. You are one of the few people in this world I have  

discussions like this with. But in this case, for better or for worse,  

I am right about this. Go look up "load dump". Oh, and I stand by the  

self-exciting alternator too. 



 	  Quote: 	
		   P.s.  Here is my opinion, and I have tried it.  If you are flying  

 around

 and suspect you have a bad battery, DO NOT TURN OFF THE ALTERNATOR to

 check your battery voltage, it very well might not come back on with

 zero, or even near zero battery voltage.  It is also entirely possible

 that the aircraft will be subject to inductive voltage kicks from

 operating that alternator without a battery (as Brian pointed out).

 These might even be high enough to cause equipment damage under the

 right conditions.  As the pilot in command, you'll have to make the

 decision which possibility is worse for you.  However, my testing

 confirms that if you turn off the alternator with a dead battery,

 turning it back on will accomplish nothing unless you are lucky enough

 to have just a little something left in the battery to excite the

 alternator allowing it to get back on line.


	


For externally-regulated alternators, this is 100% true. This means  

almost all aircraft.



 	  Quote: 	
		   Next, regardless of alternator OR generator, if either is on-line and

 you have a bad battery, the power you DO generate will power the  

 landing

 gear motor, will run all your lights, and HOPEFULLY will not damage  

 your

 avionics.


	


Ah, landing gear. When the gear is finally down and the gear motor  

shuts off, look for one mutha' big-ass load-dump event. The dump it  

takes may be in your $20,000 glass PFD. 

 	  Quote: 	
		   Given the tests I just ran in my aircraft, I would not

 hesitate to do it.  And yes, the tower reported bad hum in my

 transmissions.  However my little Apollo 360 GPS hung in there  

 without a

 hick-up.



 P.p.s.  And Brian, I am not saying you are WRONG in any way.


	


Ah, good. Because I *am* right.



 	  Quote: 	
		   I am

 saying that it is easy to switch back and forth between discussing

 apples and oranges during any kind of electronic discourse of this

 nature.  Apples remain apples and oranges remain orange.  However,  

 when

 you put them in the same bowl, we need to be careful not to act like

 they are the same fruit.  My 2 cents anyway.


	


<sigh> And here I thought *I* was the most anal-retentive, pedantic  

asshole on this list!



(Love ya' Mark. 



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

l39parts(at)hotmail.com
Guest

Posted: Thu Feb 21, 2008 12:59 am Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

and now, Mark, all you need to do is go through and rebut Brian's points, point by point, then Brian will get mad and leave the list for a year.  It's deja vu all over again.

 	  Quote: 	
		   Subject: WARNING, DO NOT READ! It's a Mark & Brian discussion! 

 Date: Wed, 20 Feb 2008 17:50:44 -0500

 From: mark.bitterlich(at)navy.mil

 To: yak-list(at)matronics.com

 --> Yak-List message posted by: "Bitterlich, Mark G CIV Det Cherry Point, MALS-14 64E" <mark.bitterlich(at)navy.mil>

 The subject was written to warn the people that get bored from reading

 "Mark and Brian" discussions. Now you can't say you were not warned! 

 If you went this far, .. Be advised that this is a discussion on

 Alternators and Generators. More of the same. Interesting to few but

 the very dedicated electronic types. 

 Ok Brian... I'm going to take some pot shots here, and the YAK readers

 will take it in the shorts from boredom I am sure!  

 Double >>'s from me. 

 Single >'s from Brian. 

 No >'s, this reply. 

 >> P.s. Another little tidbit between Alternators and Generators.

 >>

 >> 1. If your batteries ever go totally dead in the air or on the 

 >> ground... I mean zero or really LOW battery voltage.... And the 

 >> alternator is not already on-line... It will never turn on.

 >Not entirely true. Self-exciting alternators will. 

 >Even a regular alternator will come on line if you can get all the 

 >loads off the bus first.

 True. Now name a light civil aircraft with a self-exciting alternator

 installed. The small B&C PMG "Alternator" will in fact do that. It

 also has no field input winding as you know. It uses permanent magnets.

 Yes, the "Alternators" on the EA-6B Prowler have a PMG winding as well

 that is then used to excite the main field. These are indeed

 self-exciting and it is agreed that such models exist. These are 3

 phase 30 KVA models by the way. And yes, I have 38 years experience

 working with self exciting alternators, (HANDS ON Brian) but I have yet

 to see one on a Cessna. If the readers of this list want to discuss the

 power generating systems on a 747, then heck yes! However, sorry... not

 on the YAK LIST and not on the Chevy in your garage either. 

 As far as a "regular" alternator coming on line with all loads

 removed..... I'd like to see it done please. I went out to my 68 Camaro

 and tried it. It did not work. I went out to a Cessna 180 (1974 model)

 and it did not work. Then a 182, then a Piper 140, then a YAK-52TW. No

 cheese. I suspect that what you are suggesting is connecting a wire

 jumper directly from the output to the field. Impossible to do

 in-flight, and not a bright thing to do on the ground. If I am wrong

 here, please correct me. Never-the-less, I tried exactly that and it

 failed to work. 

 So yes, again with respect, your point in theory is entirely valid.

 However, I do not consider it to be Germaine unless you can point to

 exactly which make and model of aircraft, or even automobile that you

 actually made it work on. 

 >> It needs a little juice to get it going so to speak.

 >That is true. OTOH the reason that the generator comes on-line without

 the battery is the residual 

 >magnetism in the field. 

 I concur, and a generator does not come from the factory that way. It

 has to be "FLASHED" in order to start working the very first time.

 Agreed, some manufactures' did that for you back in the day. Depending

 on how long it "sat" it sometimes still needed it upon installation. 

 >The alternator has the same thing. 

 Define what you mean by the "same thing". An alternator NEVER needs to

 be "flashed" coming out of the box. It does NOT rely on self-induced

 magnetism, and it is not a design FEATURE.... Except.... On very special

 models usually found on commercial or military aircraft designed for the

 express purpose of running WITHOUT any kind of battery at all. 

 >You can see this by disconnecting the 'B' lead, putting a voltmeter on

 it, and spinning up the alternator. 

 >You will get some output. It should be enough to excite the field to

 bootstrap the alternator to full 

 >output as long as nothing else is using that output. As I said, that is

 how a self-exciting alternator 

 >gets going. And most internally-regulated alternators are self

 exciting.

 Interesting theory. How much does that meter load the output do you

 think? Yes, I am sure you can get some voltage on a meter. In my recent

 experience, not enough current to get the field excited though. It did

 not work on any test I ran. As you pointed out, there are a lot of "1

 wire" alternators out there. I have one on my 68 Camaro... A 100 amp

 alternator. It does NOT self-excite. Period. 

 >But there is another issue. Neither a generator system nor an

 alternator system should 

 >be operated without a battery in the circuit. 

 I assume we have now jumped back to common general aviation aircraft,

 because only a very few modern tactical military aircraft have ANY kind

 of battery even installed! Granted some do have APU's. However, take

 the whole A-6 product line for example. No battery except for

 activating a spin assist circuit, and their alternators run the whole

 aircraft without a problem....no batteries needed. 

 This is an example of "reverse nit-picking" and I admit it. Point is,

 some systems were designed to be operated with a battery and some

 without. Some alternators can self excite, most can not. Discussions

 then need to stay targeted on one thing at a time. 

 ANYWAY....Yes, I agree.... On models designed to run with a battery it

 is true that it is inadvisable to run the system without one. Unless

 maybe your life is at stake. Say, IFR at night. Or, as a young Marine

 trying to get back to the base after his battery had been stolen out of

 his car and no money to buy a new one, and too honest to swipe someone

 else's. A 12 volt lantern battery WILL excite a car alternator enough

 to get it going. Been there, done that, have the tea-shirt. Drove 500

 miles back to the base exactly that way. 

 >The battery is needed to stabilize the voltage. Without it you have

 nothing to absorb the 

 >excess output when you load-dump. Neither an alternator nor a generator

 can change its 

 >output suddenly. It takes time for the magnetism in the field to ramp

 up or ramp down 

 >with a field current change. (Current lags voltage in an inductor if

 you want to get technical.) 

 Yes... I am familiar with AC theory Brian... And yes I remember ELI the

 ICE man. But... You kind of make it sound like without the battery,

 everything will self-destruct. 

 >That means that, without a battery, turn off the landing light and

 watch the alternator or 

 >generator create an over voltage event.

 Better yet, leave it on and watch it tend to smooth out voltage

 excursions. 

 That said, I went out to my YAK-50 last night and disconnected the

 battery. I then started it. I then ran up the engine to about 50 % and

 called the tower and flew it around the pattern with no battery

 connected. Nothing burnt out. Everything worked fine. It was not much

 of a risk really. On a flight a few years ago I blew the battery fuse

 in flight. Well... Actually the fuse holder fell apart... But same

 thing. I never even knew it until I idled the engine down and

 everything in the cockpit went dead. 

 This morning I went out to my old piece of junk Renault Alliance. I

 started the car. I then rev'ed the engine up to 2000 RPM and

 disconnected the battery. It took two people to pull this stunt off. I

 then drove it around the block. Nothing bad happened. Of course I did

 not have a $10,000 Avionics Stack fired up either. 

 >Now we have said WAY more about alternators and generators than anyone

 else wanted to hear. 

 Probably so. 

 Mark Bitterlich

 P.s. Here is my opinion, and I have tried it. If you are flying around

 and suspect you have a bad battery, DO NOT TURN OFF THE ALTERNATOR to

 check your battery voltage, it very well might not come back on with

 zero, or even near zero battery voltage. It is also entirely possible

 that the aircraft will be subject to inductive voltage kicks from

 operating that alternator without a battery (as Brian pointed out).

 These might even be high enough to cause equipment damage under the

 right conditions. As the pilot in command, you'll have to make the

 decision which possibility is worse for you. However, my testing

 confirms that if you turn off the alternator with a dead battery,

 turning it back on will accomplish nothing unless you are lucky enough

 to have just a little something left in the battery to excite the

 alternator allowing it to get back on line. 

 Next, regardless of alternator OR generator, if either is on-line and

 you have a bad battery, the power you DO generate will power the landing

 gear motor, will run all your lights, and HOPEFULLY will not damage your

 avionics. Given the tests I just ran in my aircraft, I would not

 hesitate to do it. And yes, the tower reported bad hum in my

 transmissions. However my little Apollo 360 GPS hung in there without a

 hick-up. 

 P.p.s. And Brian, I am not saying you are WRONG in any way. I am

 saying that it is easy to switch back and forth between discussing

 apples and oranges during any kind of electronic discourse of this

 nature. Apples remain apples and oranges remain orange. However, when

 you put them in the same bowl, we need to be careful not to act like

 they are the same fruit. My 2 ce========================&g==

Connect and share in new ways with Windows Live. Get it now!

brian-1927(at)lloyd.com
Guest

Posted: Thu Feb 21, 2008 8:55 am Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

On Feb 21, 2008, at 12:56 AM, Ron Davis wrote:



 	  Quote: 	
		   and now, Mark, all you need to do is go through and rebut Brian's  

 points, point by point, then Brian will get mad and leave the list  

 for a year.  It's deja vu all over again.


	


Hey, thanks for the vote of confidence Ron. I am sure you and I will  

be best-buds over brewskis in nothing flat.



Mark can do what he wants and rebut what he wants. It doesn't change  

the facts. What I wrote is correct and documented by others. You can  

look it up. Heck, you can even test it and prove it to yourself so it  

doesn't matter who you want to believe.



As for getting mad and leaving, mostly I reach a point where I get  

tired of the mailing lists I am on. The same discussions go on, mostly  

between the same people (including me). The noobs ask the same  

questions and get the same answers. My attempt to remedy that  

situation was met with outright hostility. So I decided to go do  

something else. By now I know the email addresses of the people I need  

to ask if I need real information about the Yak or CJ so I don't need  

the list.



For me the list is just a social thing and occasionally I can help  

someone like Craig who wanted to know something about his generator.  

Mark provided great specific detail in earlier messages and I provided  

background that I hoped would bring the forest back into view. It  

feels good to be able to help someone. But if it gets to the point  

where the feeling is too negative, well, I have better things to do  

with my life. I have people who want to learn to fly, people who want  

to learn to fly better, and I have little people who want to learn  

about science and engineering. That is a whole lot more rewarding than  

arguing with someone who hasn't done their homework.



(BTW, I am not referring to Mark in this. I know Mark has done his  

homework and I actually enjoy this sort of mental sparring. I know I  

have to have it sooo right that Mark can't trip me up on anything. 



Does that help you understand me a little better Ron? And please  

understand, I do not harbor any hard feelings. If and when we meet,  

the first beer *is* on me.

Brian Lloyd                         3191 Western Drive

brianl AT lloyd DOT com             Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

mark.bitterlich(at)navy.m
Guest

Posted: Thu Feb 21, 2008 2:44 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

I am sure I speak for Brian as well when I say that questions are always

welcomed. I can't promise an answer, but I would bet between the two of

us we could come close.   If they will bore everyone else, please direct

them to either:  mark.bitterlich(at)navy.mil  or

markbitterlich(at)embarqmail.com  



Mark

 



--

mark.bitterlich(at)navy.m
Guest

Posted: Thu Feb 21, 2008 2:58 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

Actually it was not me that drove Brian away last time.  It was people

who made ridiculous replies to his very sound logic and hard truths.

That said the only person I am going to correct in this message is you,

thank you very much and have a nice day and all that stuff. 



As an aside, there is a very basic truth between Brian and myself.  I

respect this gentleman's knowledge and I have never heard him espouse a

single viewpoint that did not make sense and was not based on excellent

logic and theory.  Every single time I have expressed a different point

of view than Brian, and we have these detailed discussions, I have

walked away with a different or broadened perspective on the matter.

Not once EVER has he made me angry.  I feel that he has some respect for

my ability in this field as well.  It is clear to both of us that what

each has learned has been accomplished with a lot of sweat and hard

work, to say nothing about experience.  It is both our profession and

our hobby. I could go on, but the real truth is that neither Brian nor

myself will ever walk away mad at each other from a simple difference in

view on a particular facet or aspect of electronics.  EVERY time that I

find myself not in agreement with Brian, the FIRST thing that comes to

my mind is: "What does he know that I do not?"   The second thing is:

"Be careful in case you are getting ready to make a fool out of yourself

here".   



Mark Bitterlich

 



--

mark.bitterlich(at)navy.m
Guest

Posted: Thu Feb 21, 2008 3:59 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

 	  Quote: 	
		  If you have an internally-regulated alternator with the internal 

VR powered from a diode trio from the stator, your alternator will 

self- excite. Every IR alternator so wired I have tried did

self-excite. 
	


 	  Quote: 	
		  I have done this with GM Delco, Ford Autolite, and Motorola.


	


I must be doing something wrong.  I went out to my Camaro... And I have

no idea who made it... Other than the fact that is the single wire type.

I started the engine and revved the engine up and then pulled the + wire

off the battery.  The Alternator stayed on and powered the car.  I then

lowered engine RPM to idle and the engine died.  What am I doing wrong

that you obviously are doing right?  



 	  Quote: 	
		  As with all steel armature pole pieces, if you apply a magnetic field 

for a long period of time it will become at least partially magnetized 

permanently. The residual magnetism in the armature will induce voltage


	


 	  Quote: 	
		  in the stator. That voltage may be (probably is) less than battery

voltage 
	


 	  Quote: 	
		  so you would never see enough output to charge the battery. But it is

enough 
	


 	  Quote: 	
		  to turn on the internal VR which will then shunt the small available

current 
	


 	  Quote: 	
		  into the field. This will increase the output which then increases the

current 
	


 	  Quote: 	
		  in the field. This positive feedback process continues until the unit

is fully 
	


 	  Quote: 	
		  on-line.


	


I understand the concept, agree with your reasons why.  I could not make

it work.  

What really bothers me is that I tried it a lot, so I clearly am doing

something different than you are, and I would like to know what.  My

conclusion at this point is that since you say it works for you, and I

can not get it to work for me, than I must be doing something different

from you and obviously wrong.  My only conclusion is that I have somehow

left a load on the alternator to the point where it can not achieve your

stated end stage.  On the airplanes, I started the engine and removed

the + wire off the battery as well.  I then again pulled the throttle to

idle and lost all electrical.  I THOUGHT I had all electrical turned off

in the aircraft under test, but I must have been in error?  



 	  Quote: 	
		  So I find your negative results very surprising. Every internally- 

regulated alternator I have used that is self-powered through the 

diode trio connected to the stator (independent of the normal diode 

bridge that feeds output to the B lead) has been self-exciting in 

the manner I have described.


	


I believe you.  I have not seen it happen.  I am perplexed.  If I am

wrong, that's ok.  However I would like to know why. 



 	  Quote: 	
		  'Taint theory.


	


Ok... I know that Brian.  I thought I was sure of my facts.  Now you

have me questioning them.  Ok... I am going to get an alternator and

belt drive it with an electric motor and run tests on what I can get out

of the blasted thing.  It may have to wait until I get back from Iraq.

I have all my interest right now targeted on building a multiple LNB

rack for an FTA dish.  



 	  Quote: 	
		  Tap the diode trio.


	


I did NOT do that!  



Alright... On my Camaro, I will disconnect the Alternator single wire

and leave it hanging.  I will start the motor and rev it up and see if I

can get any output.  I will leave the wire dangling with ZERO load.  I

did not do that last time and possibly that is why I can not duplicate

what you clearly have seen happen yourself.  



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

 	  Quote: 	
		  Sure, you can do it. If your loads remain relatively constant 

everything will work out fine without a battery. Even a honkin' 

big capacitor will do the trick. But if you take the battery out 

of the circuit, leave the alternator on, bring up the load with 

lights, pitot heat, butt-warmer, etc., and then turn off some 

large load, the output of the alternator will go a lot higher 

than you want for a short period of time. This is called a 

load-dump incident and you need something to absorb the extra 

output.


	


 	  Quote: 	
		  But even some spam-can electrical systems can run without a battery. 

I believe some of the Beechcraft are designed to run from their 

alternators without the battery on-line. It all depends on how 

you design the system.


	


 	  Quote: 	
		  But as a rule of thumb, running your electrical system in your 

car or GA aircraft (or CJ or Yak) without the battery on-line, 

you are asking for problems. Maybe not this time or the next but 

if you keep doing it, it will bite you in the butt some day.

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




We're on the same page here 100%.    

 	  Quote: 	
		  I am saying that without the battery to provide a load for the 

momentary overvoltage situation caused by load-dump, you will 

get a big spike, the energy content of which is a function of 

the inductance of the field.


	


No argument here either.  It is the same reason (in general) that diodes

are placed across the coils on relays.  



I left out your article on regulator theory.  I've always heard it being

explained as an "overshoot" caused by an immediate load reduction.  I

think your explanation is better than most that I've read, and I did not

intend to infer that load dump was anything but real or that it could

not damage avionics.  

Load dump is real, however the damage to Avionics can be greatly reduced

or eliminated with some simple care.  



 	  Quote: 	
		  Doesn't your Yak-50 use a B&C PM alternator? 


	


No... All stock.  Big ole heavy 3 KW 28 volt gen gen.  



 	  Quote: 	
		  They work differently and they will not exhibit load-dump effect. 


	


Understood.  Their "field" is pretty much a constant as I see it.



 	  Quote: 	
		  You need an alternator or generator with a field circuit. 

Also, the larger the alternator, the more profound the effect. 

You might see load-dump effect with a small field-circuit 

alternator but you will find that the energy in the spike 

is not enough to be a problem.



Hell, I would expect a PM alternator (dynamo) to run just fine without

a battery.
	




Concur.  



 	  Quote: 	
		  But lets say you are still running the stock generator. I would not 

expect a load-dump event in your Yak-50. You aren't switching big 

loads off. You don't have anything like a landing-gear motor. 

Repeat your experiment, this time with the landing light and pitot-heat

on.  
	


 	  Quote: 	
		  Turn them both off at the same time. I betcha you get a GOOD spike.


	


I intentionally avoided doing exactly that of course.  My intent was not

to say you were wrong, simply to say that it could be done if one was

even remotely careful.  Sadly, I do not have a landing light.  Fact is

the electrical load on a 50 is so trivial it is rather ridiculous to

have that monster generator in there in the first place.  

 	  Quote: 	
		  And you probably did not create a load-dump. 

That is where the problem arises. Do that again 

and remove a big load, e.g. turn off the headlights. 

Put a 'scope on the bus. It will make a believer out of you.


	


I did not mean in any way to trivialize the possible damage from voltage

spikes achieved by turning off highly inductive loads in an aircraft

with the battery disconnected.  What I meant to get across was that

using the knowledge given by knowledge of the theory, that one could

indeed operate with a dead battery and get away with it with little to

no damage using care.  



 	  Quote: 	
		  Mark, I like you. You are one of the few people in 

this world I have discussions like this with. But in 

this case, for better or for worse, I am right about 

this. Go look up "load dump". 


	


Well, I like you too!    Better yet, I trust your judgment.  I never

meant to argue with you about load dumping.  I portrayed my point of

view poorly if you left with that impression and I am sorry.  Your

points are all valid and I do not disagree with any of them.  I do admit

that I got the wrong impression from what you were saying too.  All

small points really.  



 	  Quote: 	
		  Oh, and I stand by the self-exciting alternator too. 


	


Yeah yeah... Well you have me doubting myself on that one as well.

Bothers the living hell out of me that I might have done something

wrong.  I will figure that out....  I did run the tests... Nothing

worked.  So, I must be doing something wrong if you are doing the same

darn thing and it DOES work.  When my tests failed, my conclusion was

not that your theory was wrong, only that there must not be enough

current available from the residual magnetism to get it all going.  I'll

do it again.  I can see where I might be able to get the car example to

work.  I can not see what I did wrong that caused the aircraft not to

work.  



 	  Quote: 	
		  For externally-regulated alternators, this is 100% true. This means

almost all aircraft.
	




WAIT!  Are you saying I was right about the aircraft?  So in reality the

only test that runs counter to your example is the car alternator on my

Camaro?  Really?  



 	  Quote: 	
		  Ah, landing gear. When the gear is finally down and the gear 

motor shuts off, look for one mutha' big-ass load-dump event. 

The dump it takes may be in your $20,000 glass PFD. 


	


Yep.  I agree that would be the biggest spike you would be likely to

achieve.  Good point.  



 	  Quote: 	
		  > P.p.s.  And Brian, I am not saying you are WRONG in any way.


	


 	  Quote: 	
		  Ah, good. Because I *am* right.


	


Yep, you USUALLY are.  HA!  



 	  Quote: 	
		   <sigh> And here I thought *I* was the most anal-retentive, pedantic

asshole on this list!
	




I guess you were wrong about that!    



Which brings to mind the quote:  "I once thought I made a mistake, but I

was in error"



Next question:  Are you currently doing ANYTHING with your ham ticket?

Other than encouraging others I mean.  I also wonder how many of the

list readers here are licensed hams? 



Mark

brian-1927(at)lloyd.com
Guest

Posted: Thu Feb 21, 2008 7:12 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

On Feb 21, 2008, at 3:56 PM, Bitterlich, Mark G CIV Det Cherry Point,  

MALS-14 64E wrote:

 	  Quote: 	
		  > If you have an internally-regulated alternator with the internal

> VR powered from a diode trio from the stator, your alternator will

> self- excite. Every IR alternator so wired I have tried did

 self-excite.

> I have done this with GM Delco, Ford Autolite, and Motorola.

 I must be doing something wrong.  I went out to my Camaro... And I  

 have

 no idea who made it... Other than the fact that is the single wire  

 type.

 I started the engine and revved the engine up and then pulled the +  

 wire

 off the battery.  The Alternator stayed on and powered the car.  I  

 then

 lowered engine RPM to idle and the engine died.  What am I doing wrong

 that you obviously are doing right?

No idea. It could be a bad diode trio that won't produce enough output  

to keep the internal VR alive without the idiot-light or the on/off  

line from the ignition switch. Check your diode trio.

 	  Quote: 	
		  > in the stator. That voltage may be (probably is) less than battery

 voltage

> so you would never see enough output to charge the battery. But it is

 enough

> to turn on the internal VR which will then shunt the small available

 current

> into the field. This will increase the output which then increases  

> the

 current

> in the field. This positive feedback process continues until the unit

 is fully

> on-line.

 I understand the concept, agree with your reasons why.  I could not  

 make

 it work.

Hey, stuff happens. If you feel motivated, pull the back case off and  

test the main diode bridge (6 diodes) and the diode trio.

 	  Quote: 	
		   What really bothers me is that I tried it a lot, so I clearly am doing

 something different than you are, and I would like to know what.  My

 conclusion at this point is that since you say it works for you, and I

 can not get it to work for me, than I must be doing something  

 different

 from you and obviously wrong.

Some alternators do get the power for their internal regulators from  

an external supply. You may just have a bad one or two. You would be  

amazed at just how many alternators are running around out there with  

burned out diodes and other problems.

 	  Quote: 	
		   My only conclusion is that I have somehow

 left a load on the alternator to the point where it can not achieve  

 your

 stated end stage.  On the airplanes, I started the engine and removed

 the + wire off the battery as well.  I then again pulled the  

 throttle to

 idle and lost all electrical.  I THOUGHT I had all electrical turned  

 off

 in the aircraft under test, but I must have been in error?

Well, the generator will drop off-line at low RPM. An alternator  

should produce enough output to keep itself alive. OTOH, if it is  

marginal its output might drop low enough that it stops working too.  

It all depends.

 	  Quote: 	
		  > So I find your negative results very surprising. Every internally-

> regulated alternator I have used that is self-powered through the

> diode trio connected to the stator (independent of the normal diode

> bridge that feeds output to the B lead) has been self-exciting in

> the manner I have described.

 I believe you.  I have not seen it happen.  I am perplexed.  If I am

 wrong, that's ok.  However I would like to know why.

So would I. I am guessing it is something about that particular  

alternator.

 	  Quote: 	
		  > 'Taint theory.

 Ok... I know that Brian.  I thought I was sure of my facts.  Now you

 have me questioning them.  Ok... I am going to get an alternator and

 belt drive it with an electric motor and run tests on what I can get  

 out

 of the blasted thing.  It may have to wait until I get back from Iraq.

 I have all my interest right now targeted on building a multiple LNB

 rack for an FTA dish.

Huh. I am pretty good at getting VSATs up and running. That's one of  

the things I was doing in Nigeria when I was there. Need help? I could  

stand to make a few bucks. 

 	  Quote: 	
		  > Tap the diode trio.

 I did NOT do that!

 Alright... On my Camaro, I will disconnect the Alternator single wire

 and leave it hanging.  I will start the motor and rev it up and see  

 if I

 can get any output.  I will leave the wire dangling with ZERO load.  I

 did not do that last time and possibly that is why I can not duplicate

 what you clearly have seen happen yourself.

Could be. I am thinking your alternator may not be completely healthy.

 	  Quote: 	
		   We're on the same page here 100%.

> I am saying that without the battery to provide a load for the

> momentary overvoltage situation caused by load-dump, you will

> get a big spike, the energy content of which is a function of

> the inductance of the field.

 No argument here either.  It is the same reason (in general) that  

 diodes

 are placed across the coils on relays.

Well, not quite. It *IS* overshoot. It comes not from the VR response  

time but rather the time it takes for the field to collapse. B-field  

in the rotor stores energy. That energy sustains the field current for  

some time after the VR turns it off. And it is worse with a clamping  

diode.

 	  Quote: 	
		   I left out your article on regulator theory.  I've always heard it  

 being

 explained as an "overshoot" caused by an immediate load reduction.

It is but it comes from the field not reducing instantly, not from the  

VR.

 	  Quote: 	
		   I

 think your explanation is better than most that I've read, and I did  

 not

 intend to infer that load dump was anything but real or that it could

 not damage avionics.

 Load dump is real, however the damage to Avionics can be greatly  

 reduced

 or eliminated with some simple care.

I agree.

 	  Quote: 	

> Doesn't your Yak-50 use a B&C PM alternator?

 No... All stock.  Big ole heavy 3 KW 28 volt gen gen.

> They work differently and they will not exhibit load-dump effect.

 Understood.  Their "field" is pretty much a constant as I see it.

Exactly.

 	  Quote: 	
		  > Turn them both off at the same time. I betcha you get a GOOD spike.

 I intentionally avoided doing exactly that of course.  My intent was  

 not

 to say you were wrong, simply to say that it could be done if one was

 even remotely careful.  Sadly, I do not have a landing light.  Fact is

 the electrical load on a 50 is so trivial it is rather ridiculous to

 have that monster generator in there in the first place.

And with no significant loads you will never see load dump. I bet you  

could run that all day without a battery and never have a problem.

 	  Quote: 	
		  > And you probably did not create a load-dump.

> That is where the problem arises. Do that again

> and remove a big load, e.g. turn off the headlights.

> Put a 'scope on the bus. It will make a believer out of you.

 I did not mean in any way to trivialize the possible damage from  

 voltage

 spikes achieved by turning off highly inductive loads in an aircraft

 with the battery disconnected.  What I meant to get across was that

 using the knowledge given by knowledge of the theory, that one could

 indeed operate with a dead battery and get away with it with little to

 no damage using care.

I agree with that. See, we are just a pair of agreeable chaps. Time  

for a group hug!

 	  Quote: 	
		  > Mark, I like you. You are one of the few people in

> this world I have discussions like this with. But in

> this case, for better or for worse, I am right about

> this. Go look up "load dump".

 Well, I like you too!    Better yet, I trust your judgment.  I  

 never

 meant to argue with you about load dumping.  I portrayed my point of

 view poorly if you left with that impression and I am sorry.  Your

 points are all valid and I do not disagree with any of them.  I do  

 admit

 that I got the wrong impression from what you were saying too.  All

 small points really.

As I have gotten older I find that I tend to not be completely clear  

in my writing. I need to fix that.

 	  Quote: 	
		  > Oh, and I stand by the self-exciting alternator too. 

 Yeah yeah... Well you have me doubting myself on that one as well.

 Bothers the living hell out of me that I might have done something

 wrong.  I will figure that out....  I did run the tests... Nothing

 worked.

I believe you. What's different? We need to figure that out, probably  

off list. 

 	  Quote: 	
		   So, I must be doing something wrong if you are doing the same

 darn thing and it DOES work.  When my tests failed, my conclusion was

 not that your theory was wrong, only that there must not be enough

 current available from the residual magnetism to get it all going.

And that could be. Not all internally-regulated alternators are self- 

exciting. Yours might not be.

 	  Quote: 	
		   I'll

 do it again.  I can see where I might be able to get the car example  

 to

 work.  I can not see what I did wrong that caused the aircraft not to

 work.

If you want to play with it, open up the back and add a wire to the  

power input to the VR. Now you can see what is happening inside your  

particular alternator.

 	  Quote: 	
		  > For externally-regulated alternators, this is 100% true. This means

 almost all aircraft.

 WAIT!  Are you saying I was right about the aircraft?

Spam cans, yeah.

 	  Quote: 	
		   So in reality the

 only test that runs counter to your example is the car alternator on  

 my

 Camaro?  Really?

Well, I spend a lot of time in the experimental aircraft area. Most  

use internally regulated automotive alternators and all that I have  

said is true. I have never seen a production aircraft that flies under  

a normal-category AC use an internally-regulated alternator until  

recently. You can now get internally-regulated alternators from Plane  

Power that are STC'd for many aircraft. I think they need an external  

power source for the VR and field tho'. They probably won't self-excite.

 	  Quote: 	
		  > Ah, landing gear. When the gear is finally down and the gear

> motor shuts off, look for one mutha' big-ass load-dump event.

> The dump it takes may be in your $20,000 glass PFD. 

 Yep.  I agree that would be the biggest spike you would be likely to

 achieve.  Good point.

>> P.p.s.  And Brian, I am not saying you are WRONG in any way.

> Ah, good. Because I *am* right.

 Yep, you USUALLY are.  HA!

> <sigh> And here I thought *I* was the most anal-retentive, pedantic

 asshole on this list!

 I guess you were wrong about that!  

Yeah, I guess I was. (hee hee)

 	  Quote: 	
		   Which brings to mind the quote:  "I once thought I made a mistake,  

 but I

 was in error"

Oh hell, I am wrong all the time. I just don't let anybody know. 

 	  Quote: 	
		   Next question:  Are you currently doing ANYTHING with your ham ticket?

 Other than encouraging others I mean.  I also wonder how many of the

 list readers here are licensed hams?

I am on the air but mostly using it to teach the kids about  

electricity and electronics. When I operate it is mostly PSK31. I am  

planning to play with MFSK. I am also building a couple of little I/Q  

transceivers using Tayloe mixers with all the modulation and  

demodulation being done in software. Other than that, not much.

And I think we have gone as far as we reasonably can with this topic  

on the Yak list. Let's continue privately.

--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)

I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry

PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

dave(at)davelaird.com
Guest

Posted: Thu Feb 21, 2008 8:20 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

Brian and Mark,



While I can appreciate someone who can assemble, or even spell,  a  

VSAT antenna, do either of you guys have

experience with a retro-encabulator?   



Please see the following video for fodder:



http://youtube.com/watch?v=PtuqjFf7-N4



Most of what he says in the video reminds me of the language in some  

of your posts!  



Enjoy,



Dave Laird

N63536  1983 CJ6A  "Betty"

Dallas  (ADS)



p.s.  Brian I put a B&C alternator into Betty a couple of years  

back....so she doesn't have your self excited Delco Truck Alternator  

anymore!

brian-1927(at)lloyd.com
Guest

Posted: Thu Feb 21, 2008 9:06 pm Post subject: WARNING, DO NOT READ! It's a Mark & Brian discussion!

On Feb 21, 2008, at 8:18 PM, Dave Laird wrote:



 	  Quote: 	
		   



 Brian and Mark,



 While I can appreciate someone who can assemble, or even spell,  a  

 VSAT antenna, do either of you guys have

 experience with a retro-encabulator?   



 Please see the following video for fodder:



 http://youtube.com/watch?v=PtuqjFf7-N4



 Most of what he says in the video reminds me of the language in some  

 of your posts!  


	


Jeez! The only difference is I use real words. Trust me, that makes it  

MUCH harder for someone to twig to my BS.



--

Brian Lloyd                         3191 Western Drive

brian HYPHEN 1927 AT lloyd DOT com    Cameron Park, CA 95682

+1.916.367.2131 (voice)             +1.270.912.0788 (fax)



I fly because it releases my mind from the tyranny of petty things . . .

— Antoine de Saint-Exupéry



PGP key ID:          12095C52A32A1B6C

PGP key fingerprint: 3B1D BA11 4913 3254 B6E0  CC09 1209 5C52 A32A 1B6C

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