Stator wiring help!

[beebe]

I need some help on the stator wiring. I was under the impression that the CDI generated its coil voltage from the battery. So, I took the stator out to test this, but it appears that the Brown and Green wires from the CDI go to two poles on the stator. These two poles have larger windings, which leads me to believe they supply the high voltage the CDI uses to charge its capacitor for discharge into the coil. Can anybody confirm this?? Maybe the factory service manual says something about it???

I measure about 126 Ohms resistance across them, where as the white wires measure like 0.7 Ohms. This would confirm that there are more windings, and thus would produce higher voltage.

So, does the CDI have a couple diodes in there to use this voltage to charge the cap??? Could I make an inverter to supply the CDI with 600vac (or whatever it measures)???



What are the PVL guys doing? Do they have their own CDI?

[edit] Oh yeah, I tried starting it with the stator removed, and there was no spark.

[beebe]

It does not appear that banshee's have this feature...
So what does it do? Hmmmm....

[SCREAMER]

lighting ,charge coil is that big one :shock: shees have lighting :?
yep the green is the low speed coil 225 -red being high speed 5.3 . plus or minus 20 % on both per my falling apart @ the seams factory destruction manual.
pvl,s use thier own system ,yamahas stuff isnt used at all .a couple wires like a 80,s dirt bike & a kill switch is it . WHATCHA GOT BREWING @ BEEBE H.P.im going with that INDIAN ignition for the rzeds , they dynamic ballance the rotor,nice :!:

OLD RACER has the pvl know how,maybe he will chime in & give you the 411.

[beebe]

Thanks Screamer!

I'm trying to get that mini flywheel going. I put a pic in the 'engines' section. Its an experiment!

I thought it'd be plug and play, guess not! :?

Are those the resistance numbers you posted?

How do you measure it?

Green to Brown = 225 ohms Low speed coil
Red to Brown = 5.3 ohms High Speed coil

Does it say how the low and high speed coils work? What do they supply power to? My Haynes just shows them disappearing into the CDI.

Anyway, thanks again Screamer, it seems you're the only one who knows what I'm talking about? I gotta get me one of those manuals!

[SCREAMER]

ah no problem beebe,lucky guess on my behalf :o .i told ya years ago now to get the original ,i dont mean to sound like a broken record but it would sure speed up your R&D . KEEP UP THE GOOD WORK 8)
im always glad when i can help further your cause,seeing as we are all in a race to go 150 mph on our rides,WANNA RACE :D A COUPLE GRAND MORE & ITS OFF TO THE RACES FOR ME :D
yep those are resistance values , the brown wire is used in both tests & they fire up the cdi.
so you tried the total loss system & it wouldnt start :lol: dont try this one @ home now but in my haste to put a few miles on my new bullet b4 the next days race i ran it without the mag cover & didnt torque the rotor nut down . well it only took till 6th gear & just as things were getting fun the bike goes waaaaaaaaaaaa.fucking rotor left the crank & flew off down the road :x luckily for me i didnt get under a wheel or i would have been gator bait. ITS ALWAYS BETTER TO BE LUCKY THAN GOOD & IM GOING TO FIND OUT IF IT REALY IS BETTER THE SECOND TIME AROUND,PEACE MY SPEED FREAK :P
GETRDONE :!:

[beebe]

:shock: I've done the same thing with my scooter, but the cover kept it all inside!! So did you find your flywheel? Still usable? Hell, that thing was spinning pretty good, did it pass you on the road? :o

Does the high speed coil generate more voltage at high rpms? Can I just feed constant AC voltage into the low speed wires of the CDI and expect it to work without the stator?

I'll see what the outputs look like on a scope, and see if I can feed them in without the stator. Time for more experimenting...

[S10RZ350]

(adj T).


200watt (adj T.)

[smurph]

The low and high speed coils are there to provide nominal voltage to the CDI regardless of RPM. Inside the CDI, there must must some circuitry to switch from low speed to high speed coils. My feeling is that it this switch point is when the voltage on the two coils is the same, with bias given to the low speed input. This probably occurs very quickly and at very low RPM. So if you could figure what voltage the CDI wants, you could just feed that to both Red and Green inputs, with Brown being the common. The low speed coil is probably used to make for easier starting.

There are 2 stators out there for our U.S.A model 84-85 RZs. One for the RZ350L/N (84?), which was not sold in CA, and one for the RZ350NC (85?) that was sold in CA and the rest of the states.

RZ350L/N:
Br to G: 225 ohms +- 20 % (Low Speed)
Br to R: 5.3 ohms +- 20% (High Speed)
W to W: 0.4 ohms +- 20% @ 68 degrees F
CDI: 29K-50
Rotor/Flywheel: 29L-50

RZ350NC:
Br to G: 133 ohms +- 20 % (Low Speed)
Br to R: 5.3 ohms +- 20% (High Speed)
W to W: 0.5 ohms +- 20% @ 68 degrees F
CDI: 52Y-50
Rotor/Flywheel: 51L-50

So Stan, I think you have the 51L stator, based on your measurement on your low speed coil.

There is most definitely some diodes in the CDI to rectify the A/C output. In fact, if you could figure the correct polarity, one may be able to just feed the CDI inputs DC at the needed voltage.

Possibly unrelated to this post, now one can see why running a 52Y CDI on a 29L stator is problematic. The instructions for doing so call for switching the G and R wires.

My theory on the use of the 52Y CDI on a 29L stator is that by switching the G and R wires, the voltage crossover between the two coils happens so quickly, the 52Y CDI never switches over to the high speed input. So it remains on the low speed input (supplied by the high speed coil, in this case). It just happens to work. You just may need to kick a little harder to get the voltage up on the high speed coil quicker.

With that in mind, I propose a new way to adapt a 52Y CDI to a 29L stator. Why not add a 330 ohm resistor in parallel (between the G and Br wires) to the low speed coil. This would make the resistance between the G and Br wires approx. 133 ohms just like the 51L stator. And Ohm's law would do the rest and insure the 52Y CDI is happy.

Could someone that has a 52Y CDI hooked to a 29L stator test this? Let me re-phrase that... Could someone that has a 52Y CDI hooked to a 29L stator take a chance on creating a mushroom cloud over the test site? :)

Steve

[beebe]

Interesting. I put an oscilloscope on my bike and took some measurements, I'll post the results later.

In short, the output of the high/low speed coils is around 240v.

[beebe]

Ok, I ran the bike and measured the three charge coil wires with an oscilloscope. I measured from the wire to ground:







These are the general shapes of what the scope showed. I would assume that coming out of the coil would be some sort of AC. But it appears that these are just 1/2 of the AC waveform. I don't know enough about measurement, but I'm assuming we don't see the negative half of the AC because it is chopped out by diodes upstream in the CDI???

So to see what the charge coils are actually outputting, would I need to spin the rotor around the stator and measure with nothing connected?

Thus, if I were to feed the CDI what it needs, would I need to give it 240x2 ~= 500 vac??? OR ~200vdc?

Also, I'm guessing the CDI isn't too particular about wave shape and "cleanliness".

Interestingly, it runs with the brown wire disconnected, but disconnect any other and it wont run. I'll try swapping high and low speed wires and see if I can get it started.

Why not add a 330 ohm resistor in parallel (between the G and Br wires) to the low speed coil. This would make the resistance between the G and Br wires approx. 133 ohms just like the 51L stator.

I don't think the CDI looks "downstream" at the resistance. I think the lower resistance coils just have fewer windings and produce lower voltages. I'm thinking the reason the red and green wires are switched is due to internal re-wiring on the later CDI or stator??? If it shows the diagram, maybe the center-tap wire changed colors between the two models??? Just a guess.

[smurph]

On a magneto system, voltages are not fixed. The impedance (AC resistance) changes with frequency (a function of RPM). You may see voltages as high as 60 volts from just the dinky pickup coil.

So this is a different ball game as compared to our 60 cycle AC current where coils with a defined number of turns produce a defined amount of voltage.

Also, Im thinking the magneto is not an opposite pole type of AC generator, at least on the CDI source coils. The coils are close to each other and do not oppose one another. You don't have a positive magnetic pole over a coil at the same time there is a negative pole under it. What you may be seeing is a positive voltage being generated and a little negative voltage being created due to the flux field collapsing. Or bouncing.

Are you taking the readings between the Brown and Red wires and then the Brown and Green wires? Or are you reading the Green wire and Ground and Red wire and Ground? Because I don't know how the magnets on the rotor are polarized. Are their poles all pointed to the center? I suspect they are all positioned to produce mostly positive voltages on the coils. But then the manual states that the lighting coils produce a "full wave three phase". So maybe some of the magnets are polarized differently? I need to get a samll magnet and test this. I say this because if the magnets polarity is staggered, you should see a negative pulse too. Not a true sin wave, but a wave like this:



Take a look at this:



I have built a PCB based on this circuit. But I have not really tried it because I have some studying to do on this confounded stator! I have ideas about the low and high speed coils and there use. But as I said above, I only have theories. This circuit only assumes one source coil. And there are most definitely two on our RZs.

I gave up on the project over a year ago because Borut already has a nice affordable CDI replacement. I would be re-inventing the wheel, so to speak.

But this page has a lot of information that may interest you. http://www.sportdevices.com/ignition/ignition.htm Check out the ignition machine at the bottom. I have been gathering parts to build one. Guess what that motor is? :)

Also, there is something new at the top that I haven't see before and it does interest me. It's a DC -> DC converter circuit that could be integrated into the original CDI circuit.

Steve

[beebe]

I was measuring from the negative battery terminal to each wire respectively.

I measured the pickup coil output as well, it looked like:


I just put a small magnet inside the rotor, and it looks like the magnets are N-S circumferentially and evenly spaced:

But I have a Banshee rotor which has a stainless shield so I can't see the actual magnets.

Suppose the following, you have a half wave rectifier and a load:

If you put an oscilloscope between the diode and the AC input, what would you see? Would you see the un-changed AC input signal, or would you see the 1/2 wave rectified signal as affected by the diode? I don't know, maybe it would depend on where you clipped the probe ground wire??? Electrical is my weakness!

I'll have to read up on that site you posted, it looks interesting. But on the stock curve, the advance peaks at 4k rpm, do you think they did this for emissions? I'd say you could skip right to 6k+ where you're making power and are worried about detonation, then taper off as needed. Are you giving up that much ridability going to fixed timing? (i.e. PVL?)

The motor used to spin the ignition test machine? It looks like a router or something? PCB drill?

[smurph]

You got it! A router. Hook that puppy to a rheostat and a tach and there you go.

So the magnets are staggering the poles... You should get AC voltage from one coil then. Measure the voltage between the G/R wires an the Brown wire. Just like you did to get the resistance of the coils. Don't concern yourself with battery terminals, as it has nothing to do with the CDI source coils.

In your half wave rectifier, it does depend on where you probe it. If you probed each pin of the resistor, you would see a half wave. If you probed pin 1 of the diode (closest to the AC source) and pin 2 of the resistor (also closest to the AC source), you would see the full AC wave.

So for our efforts on the RZ CDI, probe the Green and brown wires. And then the Red and Brown wires.

BTW, I'm not EE expert. But I played one on T.V. :) I took a couple of EE classes when I was in college. So take all of this with a grain of salt. I can grok the simple stuff, but it's all from the classroom and text books. I have maybe 20 hours experience with an oscilloscope. (I sure would like to have one now though) I can understand circuits like the CDI circuit above, but I can not design them. But I can make many simple little devices like rectifiers and stuff. So I'm still learning... 20 years later. I still find it fascinating.

Steve

[beebe]

Ok, so today I ran it on the scope again:

First measurement between the brown and green wires:


The probe goes to the green wire, and the ground strap to the brown wire.

Then I moved the probe wire over to the red/white wire:



These measurements were taken at idle. At 5k rpm, Brown-Green remains about the same voltage, but Brown-Red jumps to 192v Pk to Pk.

Interesting.... So it looks like 200vac is what it needs???

[Shanelum58@gmail.com]

Hi shane here hopn sum1 can help me locate a good stator 4 my 81 rd 350 lc part no 4l0 81410 -50