charging system question(s)

[salzy]

Ridetard, you may or may not be getting what you need for an answer but I'm learning a pantload. Thanks for the question.

[barny7655]

The alternator puts out 16 to 23 VAC per 1000 revs , times that bye say 4000 revs = 90 VAC out put , be nice to know what it is at 6 k ,im sure that is in the range of the 5 to 150 VAC diode capacity to cope, i know alot of harness have been damaged over the yrs letting the stator to send out excess current supply,with out damage to other parts, some one dissconnect your harness rev it to 6 k and measure the AC voltage at the pins,be nice to know ? any ways good post , thanks for all your input  we are all learning , even at my age im still lol ,nice to get the brain rattling ,Barny

[Ridetard]

Thought I understood alternators, regulators and rectifiers.. Don't have a clue as to what you just said..

Rectifiers don't adjust.. That are simply one way valves for current flow.

Not sure what you mean after that but if you have a short or open you could get voltage spikes.. Diodes (rectifiers) usually short unless you put way too much current through them. Then they blow like a fuse.. 

then it is changed to DC bye the rectfier,regulator, to a stable DC voltage with out load,

The rectifier /  regulator does not supply stable DC, it typically supplies 1/2 wave, Fullwave (HD), or 3 phase rectified DC. All have ripple. The battery acts as a capacitor to make the voltage stable.. The shunt type regulator on an HD probably does not have the loop response to make the output real smooth though it may be able to chop some of the ripple. The regulator provides a load to the alternator when the voltage is at the battery full level.

Max

Max if I may, I believe he may be referring to a Zener diode which regulates DCV after the rectifier which I would wager is full wave rectification.. I would also speculate there is a capacitor or two in the regulator to smooth things out.   A typical diode has a specific voltage drop and current rating, so you get out what you put into it, period.  A good battery provides ballast.   

I have a single phase stator.  When running, voltage at the battery is 12.4.  Pull the stator and although the battery is under load(still running), the voltage will rise to 12.6 or so.  IN other words the charging system is pulling the battery down.  It has also been my experience that a bad regulator will discharge a battery when motor isnt running. 
I need to measure the stator output  under load while the bike is running and  connected to the regulator in order to check the the true stator output.

You guys are the best.

Happy fathers day.

[Ridetard]

6.  Regulator was replaced less than 3000 miles ago..while replacing the regulator I found one lead from the stator shorted directly to ground as the insulation was worn due to vibration.  I bet that put a hell of a load on the stator.
7.  The out put from the stator (cold at 2000 rpm is 45vac...hot 31vac.)

I've done some in-depth testing of (up to very large) power transformers, so I have some familiarity with this kind of stuff in general.

I'm thinking sitting here looking at a quick rough sketch that with the stator wired Delta I can get the system up and running with six diodes.  A single grounded stator lead would cause two windings to operate into a dead short for opposite halves of their AC waveforms.  That's not good, though certainly better than full-wave shorts.  It sounds as though you might have some compromised stator windings which get weaker with heat/use.

My original question WAS..the proper procedure for checking a stator.  What is the specific resistance of the coil? As well as the factory spec regarding AC output at various RPM.

I'll let you borrow the attachments pertinent to 09 Touring bikes, however applicable they may be for you, for some ideas.

I think I paid about $7 for the pair of shop and electrical manuals in PDF format somewhere off of ebay.  The internal links won't work for you in these excerpts.

[edit: the "stator_check" pdf file isn't coming back to me properly so I'm trying to replace it with another copy...]

Thanks for the tech sheets.   Exactly what I was looking for.

R/T

[HotRock]

E=I x R   

[Admiral Akbar]

Max if I may, I believe he may be referring to a Zener diode which regulates DCV after the rectifier which I would wager is full wave rectification..

Zeners, only, haven't been used in a long time.. Problem is that they don't regulate all that well when trying to dump a bunch of current through them. They have been replaced with an circuit that dumps current but still uses a zener as a reference. Most HDs are single phase, full wave.

IN other words the charging system is pulling the battery down.

I would be more inclined to believe it just ain't putting out..

It has also been my experience that a bad regulator will discharge a battery when motor isnt running.

While it's possible.. and depending on what you are calling the regulator (include the rectifier bridge?) the last time I saw that was on a generator system. Cutout relay would stick.. I doubt it's you problem since your battery would probably now be  dead..

I need to measure the stator output  under load while the bike is running and  connected to the regulator in order to check the the true stator output.

You are probably better off with a resistive load since the rest of the charging system will clamp the voltage and not give a true measure if the performance of the system.. You'd be better off finding a current probe or measuring the voltage drop across a precision shunt. Then using Ohm's law.

E=I x R 

Man, You are dating yourself here "E" hasn't been used since the 60s or 70s..



Max

[Ridetard]

Max if I may, I believe he may be referring to a Zener diode which regulates DCV after the rectifier which I would wager is full wave rectification..

Zeners, only, haven't been used in a long time.. Problem is that they don't regulate all that well when trying to dump a bunch of current through them. They have been replaced with an circuit that dumps current but still uses a zener as a reference. Most HDs are single phase, full wave.

IN other words the charging system is pulling the battery down.

I would be more inclined to believe it just ain't putting out..

It has also been my experience that a bad regulator will discharge a battery when motor isnt running.

While it's possible.. and depending on what you are calling the regulator (include the rectifier bridge?) the last time I saw that was on a generator system. Cutout relay would stick.. I doubt it's you problem since your battery would probably now be  dead..

I need to measure the stator output  under load while the bike is running and  connected to the regulator in order to check the the true stator output.

You are probably better off with a resistive load since the rest of the charging system will clamp the voltage and not give a true measure if the performance of the system.. You'd be better off finding a current probe or measuring the voltage drop across a precision shunt. Then using Ohm's law.

E=I x R 

Man, You are dating yourself here "E" hasn't been used since the 60s or 70s..



Max

''

Without opening up a regulator, I can only speculate.  To say "E" hasnt been used in a long time is false.   Is still part of any 101 curriculum.  Ohm's law will never change, thats like redefining.  E=mc2..I suppose that hasnt been used in a long time either?  .

And yes, my regulator output is lower then my actually battery VDC at idle when things warn up.  You can put it in "Ripply's believe or not", but fact is fact.

Zeners still have there place in industry, http://en.wikipedia.org/wiki/Zener_diode#Uses

I would like to see a schematic of a regulator, so we can turn this into a factual conversation rather then a bar stool argument.

[Admiral Akbar]

Well E might be use for in the high school stuff, E is more commonly used for energy..  E (energy) in the E = mc^2 is different then the E in E = IR. This E is electromotive force or EMF or Volts.. The 2 are different..

FWIW I didn't say zeners are obsolete. I design them into circuits all the time.. The make good voltage references, transient clamps and different protection circuits like limiting gate to source voltages on mosfets. In fact there is probably one in the regulator as a reference. The problem is that they make a poor regulator as they have a inherent resistance when in avalanche mode. Especially when dumping a lot of power..Look at the graph in the Wikipedia link.. 

When I get time I'll dig up the circuit they use for the regulator.. Pretty simple..OP amp, transistor or fet, zener, some resistors and maybe a cap..

Max

[Ridetard]

Update.

Checked the stator under load,(bike running everything connected) 15.5vac to 16.4vac regardless of rpm. (1000 rpm to 3000 rpm.
I have a bad regulator.

[salzy]

When you replace it, are you going with a single or three phase stator? Just curious?

[BB]

Ridetard, you can use a "megger" to test windings on a stator if you think it is braking down under load or with heat . Most starter / alternator shops have one . I work for Onan and we have one for testing stators on the generators. Hope this helps , good luck .

[barny7655]

Ride hard , pull your old one apart and tell us whether it is a dual purpose rectifier, regulator,not sure how to melt the  appoxy though,if i had one id do it my self,cheers Barny