Help with wiring please

[lloydy1]

Can some one please give me some direction on wiring my Ducati single please?

I am rebuilding my bike which was used for club racing by the previous owner, so the magneto was removed.

I am rebuilding her to use on the road, so I have bought a 6v-60w Flywheel Magneto Alternator which has two wires coming of it, red and black.

I am looking in the manual and all the wiring diagrams seem to have three wires coming from the magnets.

I am only putting a rear break light and horn on her, so I am not looking to fully wire, only to charge battery and gain spark.

can some one please explain which is the best way forward? I am a novice when it come to wiring so it would have to be in layman's terminology.

Thanks in advance.

[JimF]

On your alternator, are there two coils?

Do you see or do you recall if the two wires were connected one apiece to the two coils?

It may be that the other end of each coil is grounded, to the engine, and thus to the frame.

I just want to be sure that the coils are not internally connected to each other and not the engine before we move ahead.

Once we know this we can move forward.


Jim

[lloydy1]

On your alternator, are there two coils?

Do you see or do you recall if the two wires were connected one apiece to the two coils?

It may be that the other end of each coil is grounded, to the engine, and thus to the frame.

I just want to be sure that the coils are not internally connected to each other and not the engine before we move ahead.

Once we know this we can move forward.


Jim

Hi Jim,

There are 4 coils on the plate with the coils all connected to each other and the 2 main wires red and black are connected to 1 coil only.

Cheers, Dave

[JimF]

Hi Dave,

I am hoping more people will chime in here to get a feel for the nature or your power source.

Is this a wide case or a narrow case?

The question I guess is if all six coils are combining to create a single AC voltage. That AC voltage might thrn be fed into a bridge rectifier for conversion to DC, and then into a DC regulator to establish a constant (regulated) to run your electrical loads and recharge the battery.

Jim

[lloydy1]

Hi Jim,

I have included a couple of pictures for you to see what I have.

I have a NC.

Dave

[JimF]

I see four coils, one that I can see is grounded.

Also, the 60-watt alternator used in the Mach 1 did have but two wires which fed into the 'black box' rectifiter/regulator that mounted under the seat.

http://www.motoscrubs.com/Ducati_Electr ... _Equip.htm

Normally yellow wires were used since the voltage was AC (changing polarity) while in most electrical circles red insulation incicates a high DC potential and black could mean a ground for the DC voltage. But I think somebody used whatever wires they had so no harm/no foul.

You need to decide if you want to use the original Ducati unit or source a more modern regulator rectifier.

The narrowcast black box was very strange by today's standards; it used common mode chokes on an iron core to achieve voltage regulation, which is now done using semiconductors with greater precision.

Also I think the narrowcase black box was a half-wave rectifier (waiting for Bob to jump in) and a full wave rectifier could achieve a little bit more power.

You could maybe use the regulator/rectifier that came out with the narrowcase bikes. It is smaller and lighter, and I beilieve a bit more modern. It has to be mounted to something metal to help draw heat away from it.

But maybe I am jumping ahead of myslef. These two options assume you are going to stay at 6-volts. I think it's gone around here a few times that you could maybe get 12-volts out of the alternator.

What voltage were you hoping to set this up as?

Jim

[lloydy1]

I was going to stick with the 6v, due to the fact I am not running lights, just horn and rear break light. Plus I have an original 6v coil.

Cheers, Dave

[ducwiz]

Hi,

nice bike indeed.
What I see in your photos is the standard 6V-60W alternator of the 250 GT-Mach1 and 350 Sebring. It has a 2-phase stator winding, the center tap is grounded.
After the huge black "static" regulator went out of production, DUCATI had issued an instructional paper how to modify the stator for using with the new electronic type marked 34.41.06. This one is a low-side serial SCR type, which uses the center tap now as the positive output, thus routed via an additional red wire out from the crankcase of the newer singles (+ 2 yellow phase wires).
I have uploaded the paper here: http://minus.com/mMuSTzLft/, here you can also see the winding and connection scheme of the four coils.
During the modification described, you have to replace the 2-wire cable with a 3-wire type. Do not use household PVC insulated cable, because this is not resistant against mineral oil and high temperatures.
Another option: desolder an perfectly insulate the two center tap wires, then use a full-wave bridge regulator, or a bridge rectifier and a power zener (LUCAS?) or single phase SCR shunt regulator. Different japanese or chinese regulators for this purpose seem to be available on the market.

cheers Hans

[Jordan]

>Another option: desolder an perfectly insulate the two center tap wires, then use a full-wave bridge regulator, ...

cheers Hans
==========

Hi Hans,
Does this really work? I heard others say that the centre tapped alternator needs more attention before it will work properly with a full-wave rectifier.
If I remember correctly, they said that the coil-halves needs to be differently connected somehow, so as to most effectively provide current.
Sorry, I'm not sure of the detail, or even if this is correct.

Jordan

[lloydy1]

Hi Hans,

Thanks for the explanation , as I am a complete novice to electrics and electronics could you please attach some links to the regulator etc that I would need. I have copied and pasted the part number you put in your reply but all I get is and oxygen bottle regulator Sorry for being thick.

Dave